Food Supplements

This invention relates, inter alia, to certain compositions, uses thereof, and to food supplements and drinks for human consumption containing the compositions.

The high consumption of wine in France is through to be an important dietary factor in the low incidence of coronary heart disease (CHD) mortality and has been suggested at least in part to provide a possible explanation for the phenomenon known as the "French Paradox" (Ranaud & De Lorgeril 1992), France being an exception compared with most other countries because CHD mortality is low despite a high intake of saturated fat.

There is a considerable literature on the alleged beneficial effects of rod wine in relation to prevention of coronary heart disease (CHD). Epidemiological data suggest the protection afforded by wine is superior to that of other alcoholic beverages such as beer and spirits, indicating that factors other than alcohol content in wine is contributing to the effect (St. Leger et al., 1979; Renaud & De Lorgeril 1992). In a prospective study in Copenhagen, Denmark various parameters (including alcohol intake, smoking habit and body mass index) were assessed in 13,285 people succeeded by a 12 year follow-up of mortality. It was shown that low to moderate intake of wine (but not beer or spirits) was associated with lower mortality from cardiovascular and cerebrovascular diseases and other causes (Gronbaek et al., 1995). These results confirmed those previously reported in the USA (Klatsky & Armstrong, 1993).

There is growing evidence that the free radical chain reaction of lipid peroxidation involving the oxidation of low density lipoproteins (LDL) plays an important contributory role in the development of atherosclerosis and CHD (Steinberg, 1993).

Frankel et al (Lancet 1993 341, 454-457) examined the ability of dilute, dealcoholised red wine to inhibit the oxidation of human LDL, in vitro, and found the wine to be very active as an antioxidant. The authors suggested that the routine consumption of red wine may "reduce oxidation of lipoproteins and reduce thrombotic phenomena". However, the authors admitted that "we need to know more about the pharmaco-kinetics of wine flavonoids and the absorption and metabolism of wine phenols . . . if we are to evaluate further the potential role of antioxidant compounds in red wine in reducing CHD".

Flavonoids belong to a group of substances called polyphenols (PP), so named because they contain two or more phenolic groups. Polyphenols occur abundantly in red wine and consist of a large number of different chemical substances of varying molecular weights. The chief polyphenol components of grapes and wine, and their concentrations, are described by Shahidi & Nazck (1995) in "Food phenolics: sources, chemistry, effects and applications" (Technomic Publishing Co., Lancaster Pa., USA) p136-146. Among the polyphenols are the following classes: flavonoids (a term often used to denote polyphenols in general, but more commonly in Europe to denote only the flavones), the flavanols, proanthocyanidins (also called procyanidols, procyanins, procyanidins and tannins) and anthocyanins.

The flavones are compounds with a basic structure shown in FIG. 2 in which two benzene rings (A and B) are linked with a heterocyclic six member ring C containing a carbonyl group. Ring B can be joined in position 2 (as illustrated) to give a flavone or to position 3 to give an iso flavone. Hydroxylation can occur at positions 3, 5, 7 and 3', 4', 5' to give compounds called flavonols. Typical examples of flavonols are: quercetin, (hydroxylated at positions 3, 5, 7, 3', 4'), kaempferol (hydroxylated at positions 3, 5, 7, 4'), and myricetin (hydroxylated at positions 3, 5, 7, 3', 4', 5'). They can exist naturally as the aglycone or as O-glycosides (e.g. D-glucose, galactose, arabinose, rhamnose etc). Other forms of substitution such as methylation, sulphation and malonylation are also found.

The flavonols have a basic structure shown in FIG. 3. The two most common flavanols are catechin (hydroxyl groups positions 5, 7, 3', 4') and its stereo-isomer opi-catechin. The hydroxyl groups can be esterified with gallic acid (shown in FIG. 4). The proanthocyanidins are polymers of catechin and/or epicatechin and can contain up to 8 units or more.

The anthocyanins are coloured substances with a basic structure shown in FIG. 5. They are sometimes called anthocyanidins. Typical examples are: cyanidin (hydroxylated at positions 3, 5, 7, 3', 4'), delphinidin (hydroxylated at positions 3, 5, 7, 3', 4', 5') and pelargonidin (hydroxylated at positions 3, 5, 7, 3'). The hydroxyl groups are usually glycosylated and/or methoxylated (e.g. malvidin at 3', 5').

Within the general term "polyphenols" are included the dihydroxy or tri hydroxy benzoic acids and the phytoalexins, a typical example of which is resveratrol (shown in FIG. 6).

The most widely used method for the determination of LDL oxidation is to employ the transition metal copper (specifically Cu.sup.2 + ions) as a catalyst to promote the oxidation of endogenous lipid hydroperoxides. Antioxidants present in LDL, especially alpha tocopherol, delay the oxidation process and produce a so called lag phase. The process can be easily followed in a UV spectrophotometer because the oxidation reaction produces conjugated dienes which can be continuously monitored at 234 nm (Esterbauer et al., 1989). To preserve LDL from oxidation during storage, EDTA is added to complex copper and other trace elements. This excess EDTA interferes with the copper catalysed oxidation. EDTA can be removed by dialysing the LDL preparation before addition of the copper ions or an excess of copper ions can be added to compensate for those complexed with EDTA.

The results of in vitro experiments somewhat similar to those described by Frankel et al., (Lancet 1993, cited above) were also reported by Frankel et al in 1995 (J. Agricult. and Food Chemistry 43, 890-894). The authors of this publication draw attention to the difficulty of interpreting in vitro data. Thus "Although the phenolic compounds have similar chemical properties, their reducing capacity is not a very precise predictor of their antioxidant activity. In the LDL oxidation assay and other tests for antioxidant activity, the system is typically heterogeneous and physical properties, such as lipophilicity, solubility and partition between the aqueous and lipid phases of LDL can become important in determining antioxidant activity".

Indeed, those skilled in the art appreciate that extrapolation from in vitro findings to in vivo situations is frequently inappropriate. As an example, the reader is referred to the publication of McLoone et al. (1995 Proc. Nutr. Soc. 54, Abstract 168A), which shows that although the compound lutein has the potential to inhibit LDL oxidation in vitro, supplementation of the diet of human volunteers with lutein for 2 weeks (which gave a 6-fold increase in the levels of lutein in plasma) had no effect on LDL oxidation.

Some in vivo trials have been conducted to investigate the possible health benefits of red wine. Fuhrman et al, (1995 Am. J. Clin. Nutr. 61. 549-554) found that "some phenolic substances that exist in red wine, but not on white wine, are absorbed, bind to plasma LDL, and may be responsible for the antioxidant properties of red wine" and provided, in their words, the first demonstration "that red wine consumption inhibits the propensity of LDL to undergo lipid perioxidation", and that this may contribute to attenuation of atherosclerosis. However, a study by Sharpe et al, the results of which were published (Q.J. Med. 1995 88, 101-108) nearly contemporaneously with those of Fuhrman et al, found that neither consumption of red wine nor white wine had any effect "on total cholesterol, triglycerides, HDL or measures of antioxidant status, including the susceptibility of LDL to oxidation".

De Rijke et al. also investigated the matter and conducted a randomized double-blind trial. They reported their findings in 1996 (Am. J. Clin. Nutr. 63, 329-334) and stated that "The results of this study do not show a beneficial effect of red wine consumption on LDL oxidation".

Thus, to summarize, there are several reports that dilute red wine can inhibit LDL oxidation in in vitro assays, but that these findings cannot necessarily be extended to the in vivo situation. Further, the in vivo data relating to inhibition of LDL oxidation by red wine consumption are at best conflicting and there is no clear evidence to suggest that red wine consumption has any effect on LDL oxidation.

A number of compositions are now publicly available which are prepared from wine or grape by-products and which may contain polyphenols (albeit at quite low levels in some of the compositions). Among these are French Paradox capsules (available from Arkopharma). French Paradox capsules are made by preparing an extract from mare (the grape skin waste remaining after wine fermentation). Most of the polyphenols present in the grape skins are alcohol-soluble, and so tend to be extracted into the fermenting wine. Hence, French Paradox capsules have actually rather low polyphenol content. (Other publicly available compositions include an anthocyanin-containing powder (obtainable from Sefcal) made from a grape skin extract, and which is used as a food colourant, and a proanthocyanidin-containing composition ("Endorelon") prepared from grape seeds.)

Even if French Paradox capsules containing significant amounts of polyphenols, it is not clear that oral consumption of such a synthetic polyphenol composition would exert the same therapeutic effect allegedly associated with red wine consumption. For example, as explained by Goldberg (1995 Clin. Chem. 41, 14-16) the alcohol content of wine keeps polyphenols in solution in wine and in the human intestine, such that they might be available for absorption. A synthetic, alcohol-free polyphenol powder may be completely ineffective because the polyphenols are insufficiently soluble in the intestine (in the absence of alcohol) to be absorbed. Additionally, absorption into the bloodstream may not be sufficient for any anti-oxidant effect to be exerted on LDL-intimate association of the polyphenols with the LDL fraction may be required.

It is recognised that many diseases are caused or provoked by a free radical oxidation mechanism e.g. cancer, cataracts, diabetes etc. Antioxidant nutrients such as vitamin E, vitamin C and others are thought to prevent free radical oxidation in many organs and tissues. Thus the absorption of polyphenols which are effective antioxidants are likely to have an effect on free radical/oxidation diseases in general, and the use of polyphenols may be much wider than a treatment or prevention of coronary heart disease.

Nevertheless, CHD is one of the major causes of mortality and morbidity in the western world, and therefore of particular interest. Pathogenesis of the condition consists essentially of a two stage process involving first the development of atherosclerotic plaques and then formation of a thrombus (clot) on the plaque (a process called thrombosis) which may cause arterial occlusion, the consequences of which can be myocardial infarction (MI) and sudden death. Other diseases which are caused by thrombosis and stroke and venous thrombosis. The initial stage in the formation of a thrombus is the aggregation of platelets which then release coagulation factors into the blood causing the production of fibrin clots. Once the blood clots are formed they can be removed by a process known as fibronolysis, which is essentially the dissolution of clots and the degradation of fibrin to degradation products. Thus there are at least two processes by which thrombosis can be prevented--inhibiting the aggregation of platelets, or increasing fibrinolysis.

Abnormal vascular smooth cell (VSMC) proliferation may contribute to the formation of obstructive lesions in coronary hearth disease, atherosclerosis, restenosis, stroke and smooth muscle neoplasms of the bowel and uterus, uterine fibroid or fibroma.

It has been known for many years that TGF-.beta. is one of the most potent cell growth inhibitors (Massague, 1990), and several authors have found that TGF-.beta. inhibits VSMC proliferation (Assolian, 1986; Bjorkerud, 1991; Owens, 1998; Kirschenlohr, 1993). Human VSMC produce TGF-.beta. in a latent, inactive form which is activated proteolytically by the serine protein plasmin, which in turn is obtained from plasminogen by a family of plasminogen activators (PAs), such as tissue plasminogen activator (tPA) (Lyons, 1990). An increase in total plasma TGF-.beta. is considered effective in inhibiting the growth of VSMC, since the latent form is converted into the active form by plasmin.

Several authors have developed methods for the estimation of the plasma level of TGF-.beta. and to search for pharmaceutical compounds which may stimulate TGF-.beta. production both in the latent and active form. In U.S. Pat. No. 5,545,569 (Grainger et al) a method is claimed for determining in vitro the effectiveness of compounds which increase the plasma level of TGF-.beta. and stimulate its production using the techniques described therein. W094/26303 (Grainger et al) discloses a method for maintaining or increasing the vessel lumen diameter in a diseased or injured vessel of a mammal by administering an effective amount of TGF-.beta. activator or production stimulator. The compound Tamoxifen (trans-2 [4 (diphenyl-1-butanyl)phenoxyl]-dimethyl ethylamine is claimed as being effective, since it stimulates the production of TGF-.beta., and increases the ratio of active to latent TGF-.beta.. Another compound showing activity is aspirin (Grainger, et al, 1995) which increases both total and active scrum TGF-.beta. in normal people but only total TGF-.beta. in patients with coronary heart disease.

An increase in platelet aggregation has also been significantly associated with prevalence (Elwood et al, 1991) and incidence (Thaulou et al, 1991) of CHD. Platelet aggregation is conveniently studied using a platelet aggregometer in which a suspension of platelets freshly obtained from blood is placed in contact with an agonist which causes aggregation. Many agonisits may be used but the most typical are arachidonic acid, ADP, collagen and thrombin. From a measurement of the maximum aggregation (%) it is possible to study the effects of the inhibitors of platelet aggregation which may be given orally or by injection to the subject. One of the most effective substances in preventing platelet aggregation is aspirin, which inhibits cyclo-oxygenase activity and formation of thromboxane, a necessary factor in thrombus formation (Moncada & Vane, 1979). Aspirin also prevents CHD, stroke and sudden death (Hennekens et al, 1988).

The fibrinolytic system constitutes a cascade of extra-cellular proteolytic reactions tightly regulated by activators and inhibitors. The enzyme tissue-type plasminogen activator (t-PA) converts plasminogen to plasmin, which in turn dissolves fibrin clots. t-PA is a glycoprotein synthesized in the endothelial cells, which is adsorbed on to fibrin in order to be activated. Plasminogen activator inhibitor (PAI)-1, is a serine protease inhibitor and acts as a specific inhibitor of t-PA. PAI 1 exists in three forms: active, latent, and as an inactive complex. It is synthesised in endothelial cells, liver and platelets.

In the circulation most tPA (95%) is complexed with PAI-1. Very little tPA and PAI-1 are in the free (active) form. A decreased fibrinolytic activity is thought to be due to an increase in PAI-1 level or activity, which results in decreased activation of plasminogen to plasmin by tPA. This is important because of reports of an association between decreased fibrinolytic activity and risk of CHD (Mehta et al, 1987) and MI. Impaired fibrinolysis, mainly due to elevation of plasma PAI-1, is a common finding in thrombotic disease. In the Northwick Park Heart Study, a prospective epidemiological study of middle aged men (40-54 at entry), Meade et al (1987) reported that a decreased fibrinolytic activity is a major independent risk factor for future CHD. Cross-sectional studies of patients with angina pectoris or previous myocardial infarction have consistently shown a decreased fibrinolytic activity in patients compared to control (Hamsten et al., 1985 and 1986; Johnson 1984; Paramo et al., 1985; Aznar et al., 1986; Francis 1988; and Olofson et al., 1989). PAI-1 concentrations have been shown to be higher in MI patients compared to controls (Hamsten et al., 1987).

Because of the role of platelet aggregation and fibrinolysis in the formation of thrombi, a method of decreasing platelet aggregation and/or increasing fibrinolysis could be employed as a method of treatment of thrombotic diseases in general, and CHD in particular.

In a first aspect the invention provides a flavonol-containing dry composition suitable for human consumption. Preferably the flavonol content of the composition comprises the compound kaempferol, myricetin or, most preferably, quercetin or a structural analogue thereof. It will be understood that reference to quercetin is intended to refer to the molecule as the aglycone, or as any glycoside thereof (typically an O-linked glycoside). Sugar residues which may be present in the glycoside include the following: arabinose, rhamnose, galactose and (preferably) glucose. The glycosides of quercetin tend to have acquired their own trivial names. For example, the rhamnose glycoside of quercetin is known as rutin.

Analogues of quercetin include those compounds which comprise a substituting group other than an --OH group at one or more of the positions 3, 5, 7, 3' and 4'. Other substituting groups include: lower alkyl (i.e. less than 5 carbon atoms) especially methyl or ethyl; acetyl; sulphyl; and malonyl. Desirably, in analogues of quercetin, only a few (i.e. preferably only one or two) of the positions are substituted with anything other than --OH groups.

Flavonols such as quercetin may readily be synthesised in vitro without great expense. Thus the composition of the invention may comprise a flavonol content prepared by chemical methods of synthesis.

Alternatively, as flavonols in general (including quercetin) are present in many naturally occurring substances, such as foodstuffs, the composition of the invention may comprise a flavonol (especially quercetin) content obtained from a naturally occurring source. Foodstuffs which contain quercetin in relatively large amounts include certain fruit and vegetables, such as apples and onions. Quercetin is also present in the polyphenol content of red wine. In particular therefore, the composition of the invention may comprise a flavonol content derived from plants. By way of explanation, such plant-derived compositions may comprise extracts of plants or parts thereof (such as tubers, fruit), which are processed in some way (e.g. by fermentation). Thus plant-derived compositions include aqueous or organic solvent extracts of plants or parts thereof, fruit juices and fermented liquors (e.g. wine) produced from plants or fruit juice, or composition obtained from any of the foregoing. The plant material is typically processed (physically and/or chemically) during production of the composition to extract polyphenols from the plant and so increase and enrich the polyphenol content of the composition. It will be appreciated by those skilled in the art that the composition of the invention is not intended to encompass within its scope naturally occurring foodstuffs or plant materials which have not been subjected to processing in any way.

Advantageously the composition may be such that the plant-derived material comprises at least 35% polyphenols, or more preferably at least 45% polyphenols.

The composition may be comprised wholly or substantially of the plant-derived material from which the flavonol content of the composition is obtained. Alternatively, the composition may comprise other material, such as flavourings, excipients, carriers and the like conventionally used in formulating compositions for human consumption.

It is preferred that the flavonol content of the composition as a whole is at least 0.01% (w/w), more preferably at least 0.1%, and most preferably at least 1-10%.

The composition of the invention is typically solid at atmospheric pressure (760 mm Hg) throughout the temperature range 10-20.degree. C. The composition may be particulate (e.g. powdered or granulated), or may be formed into capsules, tablets and the like.

The inventors have surprisingly found that compositions in accordance with the invention are effective, following oral consumption by human subjects, in inhibiting oxidation of plasma LDL, as measured by a number of criteria. Thus, the oral consumption of the composition is effective in increasing the lag phase in oxidation of isolated plasma LDL as determined by the method of Esterbauer et al (1989 Free Radic. Res. Commun. 6,67-75). Briefly, in this method, LDL isolated from a subject's plasma by ultracentrifuge is dialysed to remove EDTA, and copper ions (5 .mu.M) added to the LDL (present at 50 mg/L). The usual lag time before diene formation is about 50-60 min. Administration of the composition of the invention to the subject should give a prolongation of the lag time of preferably at least 2 minutes (or about 4% or more). The most preferred is in the range 5-25 minutes (or about 10-50%). In addition the composition is effective (following oral consumption) in reducing the amount of lipid peroxides in the plasma of human subjects (as assessed by the method of Gorog et al, 1994, and described below).

The composition may comprise flavonols (including quercetin) obtained from grapes (whole grapes or parts thereof, such as skins or juice), wine (especially red wine, which comprises much higher concentrations of polyphenols than white wine), or by-products and/or waste products of the wine-making process, such as pomace (i.e. the residue of crushed grapes following juice extraction) or marc (waste solids remaining after initial fermentation). However, flavonols such as quercetin are present in a wide range of naturally occurring materials, many of which contain a higher flavonol content than red wine and are considerably cheaper, and so may present more appropriate sources of flavonol. Examples of such materials include: fruit in general, such as apples (e.g. var. "Gravensteiner"), especially apple peel; pears (e.g. var. "Williams Christs"); bell peppers (e.g. var. "Yolo wonder"); red currants; black currants (particularly preferred as being relatively high in flavonols); lemons; cherries; cranberries; gooseberries; tomatoes; olives; and vegetables in general, including: radishes (e.g. var. "Saxa treib"); kohlfrabi (e.g. var. "Primavera"); horseradish; potatoes; onions; and asparagus.

In a particular (but not necessarily preferred) embodiment, the composition is derived from a red wine and comprises a representative profile of substantially all the flavonol compounds present in the wine (typically, although not necessarily, present in the composition substantially in the relative amounts representative of those in the wine from which the composition is derived). Such a composition may be referred to as a "total flavonol pool".

Flavonols may conveniently be obtained from red wine or other flavonol-containing liquids by absorption onto a chromatographic resin column, with elution of the polyphenol-enriched fraction from the column (typically following a washing step) by use of a 40-50% ethanol eluent, or other suitable organic solvent (such as methanol, acetone, ethyl acetate, dimethylene chloride, and chloroform--which may be in aqueous solution). The organic solvent is preferably relatively volatile (i.e. having a boiling point of between 30 and 85.degree. C. at 760 mm Hg pressure) and so readily driven off, to leave a substantially dry (i.e. less than 10% w/w H.sub.2 O) solid composition comprising flavonols. Such a method may successfully be used to obtain a total flavonol pool from red wine.

Alternatively, flavonols may be obtained from red wine or other flavonol-containing liquid by solvent extraction using a suitable organic solvent immiscible with the wine or other liquid. Alternatively, flavonols may be obtained from flavonol-containing solids by solvent extraction (typically extraction with an organic solvent such as ethanol or ethyl acetate)--the solids can then be separated from the solvent by filtration or centrifugation. The solvent may then be evaporated to leave a substantially dry, solid composition comprising flavonols.

In preferred embodiments, the composition is presented as a food supplement. This may be substance to add as an additional ingredient during manufacture of the foodstuff, or may be a separate substance to be consumed by an individual (e.g. as a tablet or capsule) substantially in isolation from (i.e. not mixed with) other food components prior to consumption (although, of course, the tablet or capsule may be taken with food). The invention thus includes within its scope a prepared product, particularly a prepared foodstuff (i.e. one which is not naturally occurring) comprising a composition in accordance with the invention. Alternatively, the composition may be presented as a solid to be made into a drink by mixing with a physiologically acceptable diluent (such as milk, water or other aqueous liquid).

The dosage of composition given to a subject is dependent on the degree of activity of the material but will be between 10 mg and 10 g per day. For the total flavonol pool obtained from red wine the preferred dose is 0.1-4.0 g/day, and more preferably 1-2 g/day, equivalent to 0.5 to 1 liter of red wine per day. The preferred dose of flavonol will be in the range 0.1-1000 mgs per day, preferably in the range 0.5-500 mgs per day, more preferably in the range 1-250 mgs per day.

Those skilled in the art will be able to take the preparation of flavonols obtained from wine, grapes or wine by products and to fractionate further to obtain compositions with more concentrated activity. This could be effected by column chromatography, solvent extraction, molecular sieves with semi-permeable membranes, or other method(s) conventionally used in the food industry. The advantage is that the weight of active substance is less, and the colour and taste of the supplement is modified beneficially.

Compositions in accordance with the invention may be prepared using the active flavonol agents in accordance with conventional food supplement or pharmaceutical practice. The diluents, excipients or carriers etc. which may be used are well known in the formulation art and the form chosen for any particular regimen will depend on the given context and the formulator's choice. In general the dose will depend on the concentration of flavonols (particularly quercetin) in the composition, and the identity of the flavonol compounds in question.

Moreover, the compositions may comprise any number of further components, such as those typically used in the food industry and/or in the pharmaceutical industry. Such components may include nutrients (especially trace elements and vitamins), antioxidants, therapeutic substances (especially those having a therapeutic effect in relation to prevention and/or treatment of CHD, in particular, aspirin), flavourings, and sweeteners (especially artificial sweeteners, such as aspartame etc.)

Examples of the above include the following: a carotenoid such as lutein, lycopene, or .alpha.-and/or .beta.-carotene; antioxidant nutrients or anti-inflammatory agents such as vitamin A, vitamin C, vitamin E (.alpha.-tocopherol and other active tocopherols), folic acid, selenium, copper, zinc, manganese, ubiquinone (coenzyme Q10), salicylic acid, 2,3-dihydroxy benzoic acid, and 2,5-dihydroxy benzoic acid.

Antioxidants such as carotenoids and vitamin E are partially destroyed in the gastro intestinal tract by oxidation. By inclusion of these compounds in the composition of the invention it is believed that this process is inhibited and more antioxidants are absorbed. Use of a composition comprising .alpha.-tocopherol and/or aspirin is especially preferred since it is believed that such a mixture affords a synergistic effect in the presence of flavonols.

Typical suitable daily doses of these additional components of the composition (and which may therefore be included in the composition such that normal consumption of the composition will give the appropriate dose) are as follows:

Thus, in one embodiment the composition takes the form of capsules, each capsule containing 500 mg of flavonol composition, with a suggested intake of one to four capsules per day. Another presentation is as a non-alcoholic drink which provides an effective dose of flavonols when dissolved in water (still or aerated) flavoured and sweetened to taste, or dissolved in a fruit juice e.g. grape, apple or orange etc.

Whilst it may be preferred for a number of reasons (e.g. social, religious, and economic) to provide an alcohol-free drink comprising the composition of the invention, such drinks can be fortified with alcohol (e.g. from vodka, gin, whisky) to give a desirable level of 5-15% alcohol depending on the consumer's taste.

Other presentations are as a food ingredient in dairy products such as milk and yoghurts, preserves, and dietary products intended as meal supplements or replacements. The above examples are illustrative only and are not intended to be limiting in any way.

In a second aspect the invention thus provides a method of inhibiting oxidation of plasma LDL in a human subject: the method comprising preparing a composition in accordance with the first aspect of the invention; and administering the composition to the subject.

The present inventors have found that not only does oral consumption of the composition of the invention inhibit oxidation of plasma LDL, the composition will also have the effect of stimulating production of transforming growth factor (TGF)-.beta. in vivo. Additionally the inventors have found that oral consumption of the composition of the invention will inhibit platelet aggregation and/or stimulate fibrinolysis, thereby decreasing the thrombotic tendency of an individual, which is of assistance in preventing and/or treating thrombotic diseases such as CHD, stroke. In particular, consumption of the composition is found to increase the level of tPA activity in plasma (as conveniently measured by means of assays such as the "Chromolize" assay [available from Biopool, Sweden] described below), the effect of which is to increase the net rate of fibrinolysis in the subject.

Accordingly in a third aspect the invention provides a method of stimulating TGF-.beta. production in a human subject; the method comprising preparing a composition in accordance with the first aspect of the invention; and administering the composition to the subject.

In a fourth aspect the invention provides a method of inhibiting platelet aggregation and/or stimulating fibrinolysis in a human subject, the method comprising preparing a composition in accordance with the first aspect of the invention; and administering the composition to the subject.

In a fifth aspect the invention provides for use of a composition, in accordance with the first aspect of the invention defined above, for the manufacture of a medicament for oral consumption by a human subject for inhibiting oxidation of plasma LDL in the subject.

In a sixth aspect the invention provides for use of a composition, in accordance with the first aspect of the invention defined above, for the manufacture of a medicament for oral consumption by a human subject for stimulating production of TGF-.beta. in the subject.

In a seventh aspect the invention provides for use of a composition, in accordance with the first aspect of the invention defined above. for the manufacture of a medicament for oral consumption by a human subject for inhibiting platelet aggregation and/or stimulating fibrinolysis in the subject (particularly by increasing the level of tPA activity in the plasma of the human subject).

The composition in accordance with the first aspect of the invention will typically confer all of the above-mentioned properties on a subject consuming the composition. The invention therefore also provides a method of making a medicament for oral consumption by a human subject for the purpose of effecting one or more of the following in the subject: inhibition of oxidation of plasma LDL; inhibition of platelet aggregation; stimulation of fibrinolysis; and stimulation of TGF-.beta. production; the method comprising preparing a composition in accordance with the first aspect of the invention; if necessary, mixing the composition with a physiologically acceptable excipient or carrier; and preparing unitary doses of the composition. Suitable methods of making the medicaments are well-known to those skilled in the relevant art.

Medicaments having this effect may take the form of food supplements or ingredients, as explained above, and should be useful in the prevention or treatment of coronary heart disease. Suitable doses of the medicaments, as explained previously, will depend on the concentration and identity of the flavonols in the composition, and on the severity of the disease state in the subject to be treated. However, as a general guide the dosage should preferably be sufficient to give the same amount of flavonol consumption as that provided by the consumption of at least one glass of wine per day (approximately equivalent to 0.25 gms of the total flavonol pool from real wine), but more preferably about 0.5-1.0 L of red wine per day (i.e. about 1.0-2.0 gms total wine flavonol).

The invention is further described by way of illustrative example and with reference to the accompanying drawings, in which:

FIG. 1 shows a graph of LDL oxidation against time (minutes);

FIG. 2 is a schematic representation of the core structure of flavones;

FIG. 3 is a schematic representation of the core structure of flavonols;

FIG. 4 is a schematic representation of the structure of gallic acid;

FIG. 5 is a schematic representation of the core structure of anthocyanins; and

FIG. 6 is a schematic representation of the structure of resveratrol.

About 2,000 liters of red wine (French 1993 Cabernet Sauvignon) was filtered to remove sediment and distilled under vacuum at 300 millibars pressure at 75 to 80.degree. C. for 1 minute, then cooled and concentrated under vacuum at 55.degree. C. and then quickly cooled down to 25.degree. C. by refrigeration. The concentrated wine was passed through a column (55 cm diameter, approximately 2 meters high) containing 65 liters of Diaion HP-20 resin. The column was washed with 250 liters of distilled water and the flavonols eluted with about 250 liters of 50% ethanol, over a period of 150 minutes or so. At the end of this time the eluate was free of polyphenols, as determined by the Folin-Ciocalteu method (described by Singleton & Rossi, 1965). The eluate was then concentrated to 35% dry matter under vacuum distillation and spray dried under nitrogen to produce about 2 kg of powder with a moisture content of 3 to 4%.

The polyphenol powder is rich in flavonols (such as quercetin) and is an excellent food ingredient having a dark red colour when dissolved in water or aqueous alcohol, being quite palatable, and giving a "bite" to the palate similar to that of red wind. The recommended daily dose is 1-2 g/day.

It is intended that references herein to the health benefits of the polyphenols, especially red wine polyphenols, refer essentially to the health benefits conferred by the flavonol fraction of the polyphenols, and in particular to quercetin and its close structural analogues and to kaempferol and myricetin.

Volunteer studies using wine polyphenols were conducted in order to determine the antioxidant activity of red and white wine and polyphenol preparations in healthy volunteers.

Subjects and Methods:

26 healthy men, aged 35 to 65, who were non-smokers, consuming a standard UK diet participated in a private and confidential study. Two weeks before the study the volunteers discontinued wine consumption. All the volunteers were asked to maintain their usual diet and lifestyle during the study. The volunteers were divided into groups which consumed the following wine or tea products with meals for two weeks in the quantities shown in table 1. The red wine was Cabernet Sauvignon (1993) and the white wine was from the region of Narbonne, France. The wine provided during the study was the only wine allowed during the experimental period. In addition the same subjects were given polyphenol powder prepared from the same batch of red wine used in the study. The powder was stored at -20.degree. C. (PP1) and a fresh sample prepared in June 1996 (PP2). The studies commenced at the beginning of September 1995 and lasted about one year.

Group Test Substance

1) Cabernet Sauvignon red wine (375 ml), containing 1.8 gms/L polyphenols

2) Vin ordinaire white wine (375 mls), containing 0.2 gms/L polyphenols

3) red wine pp powder (prepared from the same wine as given to group 1), 1 gm in two gelatine capsules

4) white wine containing in solution 1 gm red wine polyphenols (see below)

5) vodka and lemonade (10% v/v alcohol), 400 mls per day

6) 50 mgs/day anthocyanins, as grape skin extract (Sefcal, St Julien de Peyrolas, France) given as a drink

7) red wine marc (French Paradox.TM., Arkopharma, Nice, France) given as capsules (3 per day), each capsule comprising 250 mg marc

8) grape seed proanthocyanidins, as Endotelon.TM. capsules; (Sanofi-Winthrop, France) (3 per day), each capsule comprising 150 mg proaorhocyanidin

9) green tea extract (Polyphenon.TM., Mitsui Norin, Fujieda, Japan), 3 capsules per day, each capsule comprising 100 mg tea catechins as follows: 1.6% gallo catechin, 19.3% epigallo catechin, 6.4% epi catechins, 59.1% epigallo catechin gallate and 13.7% epicatechin gallate

Blood samples were drawn into K.sub.3 EDTA (1 mmol/L) 12 hours after the supper meal, before and at the end of the period of wine product consumption. Samples were centrifuged at 2000.times.g for 15 minutes at 4.degree. C. to obtain plasma. LDL was separated by density gradient ultracentrifugation using a Beckman bench top model Optima TLX with a TLA 100.4 rotor (Beckman, Palo Alto, Calif.), as follows: sodium bromide was added to plasma to a density of 1.3 g/ml and layered under a 1.006 g/ml density solution. Spinning took place at 100,000 RPM for 20 minutes at 4.degree. C. The orange/yellow LDL band was removed and spun with 1.154 and 1.063 g/ml density solutions for 30 minutes at 100,000 RPM and 4.degree. C.

The visible LDL layer was removed and dialysed with 10 mM phosphate buffered saline with 2 .mu.M EDTA for one hour using a dialysis cassette (Pierce Slide-A-Lyzer, Perstorp Biotec Company, USA) at 4.degree. C. for one hour, then with 10 mM phosphate buffered saline overnight.

Total polyphenols were determined in plasma and in the LDL fraction by the method of Singleton and Rossi (1965). Briefly, total polyphenols in plasma and LDL were measured by taking 125 .mu.l of plasma of 100 .mu.l of LDL and making up to 500 .mu.l with water. This mixture was added to 2.5 mls of Folin reagent (diluted 1:10) at 2.0 mls of sodium carbonate (75 gm/L). After mixing well the solution was incubated at room temperature for 2.5 hours and then centrifuged at 2,500 rpm for 8 minutes. The optical density of the supernatant was measured at 765 nm. Gallic acid was used as a standard for comparison.

Protein was determined by the Bradford Method (Bradford, 1976) using a kit containing for Bioquant reagent (Merck, Darmstadt, Germany).

Two independent methods were used to determine antioxidant activity.

1) Copper Oxidation of LDL

The lipoprotein (50 mg LDL protein/L) was incubated in the presence of copper sulphate (5 mM) at 37.degree. C. for 5 hours. Conjugated diene formation was continuously monitored by measuring the increase in absorbance at 234 nm and the lag time before diene-formation determined according to the method of Esterbauer, et al. (1989). FIG. 1 shows a graph of conjugated diene formation (as measured by absorbance at 234 nm) against time (in minutes). Typical curves are illustrated for samples taken at the start of the trial (0) and after 2 weeks. The lag phase is measured by extrapolating the linear part of the plots down to the x axis (as shown by the broken lines). Preferably, consumption of compositions in accordance with the invention will result in an increase of lag phase time of 2 minutes or more.

2) Plasma Lipid Peroxides

All plasma lipids and lipoproteins were selectively removed using PHM-L-liposorb (Calbiochem-Novabiochem UK). Dry PHM-L-liposorb (20 mg) was suspended in 0.25 ml of 150 mM sodium chloride containing 10 mM sodium citrate in a 2 ml brown micro centrifuge tube, the contents stirred and allowed to equilibrate for 5 minutes. Plasma (0.5 ml) or saline (blank) was then added to the liposorb suspensions, stirred and the tubes placed on a rotating mixer for 15 minutes. After centrifugation (12,000.times.g for 1 min) the supernatant was discarded and liposorb gel washed twice by 1.5 ml saline followed by stirring and centrifugation. The washed liposorb gel was suspended in 1.5 ml cholesterol oxidase-iodide reagent (BDH-Merck) and placed on a rotating mixer and stirred for 60 mins. After centrifugation (12,000.times.g for 3 min) at room temperature the optical density of the clear supernatant was measured in a spectrophotometer at 405 nm against a blank with saline, (Gorog et al, 1994).

Preferably consumption of compositions in accordance with the invention will result in a decrease in plasma lipid peroxide concentration of at least 0.1 .mu.mol/g protein.

Results

The values obtained were compared before and after treatment. Table 1 summarises the results which are given in detail in Tables 2 to 6. As shown in Table 1, those products containing abundant wine flavonols, and hence flavonols (i.e. red wine, PP1, and PP2, white wine+PP1) showed an increase in polyphenols in plasma and LDL and antioxidant activity in LDL, as measured by tests 1 and 2 above.

The two polyphenol powders (PP1, PP2) containing flavonols gave results of the same magnitude as the equivalent amount of red wine.

There was no effect with white wine, anthocyanin powder (Sefcal.TM., an extract from grape skins used as a food colorant) red wine pomace, French Paradox.TM. capsules (Arkopharma) or Endotelon.TM. (Sanofi-Winthrop, a proanthocyanidin preparation from grape seeds), nor with the green tea extract (Polyphenon.TM.) containing catechins and their esters, thus, not all polyphenols are equally active:--flavonols are preferred as having greater activity than other polyphenols, and quercetin is the preferred flavonol.

The active polyphenol preparation contained the pool of all the polyphenols and all the flavonols in the red wine, and was carefully processed so as to avoid their oxidation. Moreover it was shown that the polyphenol content of the plasma and isolated LDL was raised in those subjects receiving red wine or polyphenol obtained from red wine or grape skins.

In confirmation of the antioxidant activity of the preparation, a second assay was used in which plasma was treated with an absorbent resin which removed lipids and lipoproteins and the content of lipid peroxides determined in the resin. The content of lipid peroxides were decreased in the subjects given red wine or the polyphenol preparation. Again the magnitude of the effect of the polyphenol powder was equivalent to the amount of red wine from which it was obtained.

These experiments show conclusively that flavonols are absorbed after red wine ingestion and appear in the plasma and LDL, and that flavonols isolated from wine can have a similar effect. Moreover the absorbed flavonols have powerful antioxidant activity. The mode of action of the flavonols may be several. Primarily they can sequester metal ions such as copper and iron which promote the production of lipid peroxides in vido. These chelated ions are inactive as pro-oxidants. Flavonols, because of the high content of hydroxy groups, comprise chemical structures known to chelate metal ions, and thus destroy their catalytic properties.

Another section may be to act as a sacrificial substance which is oxidised before LDL, as is the case for alpha-tocopherol. However the invention is not limited to any one particular mode of action.

To investigate the importance of the removal of EDTA from the preparation before copper catalyst oxidation, a comparison was made using dialysis with and without EDTA, and a resin column method. When EDTA is added to the dialysate the prolongation of the lag time produced by red wine polyphenol powder did not occur or was markedly reduced. Dialysis without EDTA and the column method gave similar results. The failure of previous authors (dc Rijke et al, 1996) to obtain an effect of red wine in volunteers might be explained by the presence of EDTA in their preparations used for copper catalysed oxidation.

Conclusions

The antioxidant activity of 1 gram wine polyphenol powder is equivalent to a half a bottle of red wine. A daily dose of 1-2 g flavonol-containing polyphenol powder would have potential prophylactic activity against coronary heart disease. Other products such as grape skin extract used in the food industry as a colorant, a proanthocyanidin preparation, French Paradox capsules and a green tea extract containing catechins and their esters were inactive.

A capsule was prepared from the following ingredients by simple admixture and routine encapsulation.

Two to four capsules are taken daily with or after meals.

A capsule was prepared from the following ingredients by simple admixture and routine encapsulation.

At least three capsules per day should be taken with meals.

One gram wine polyphenolic powder, containing flavonols, is added to dry powder formula diet composition providing 405 Kcal per day (42 g protein. 43 g carbohydrate and 8 g fat, RDA of vitamins and minerals) retailed under the trade name Cambridge Diet (Cambridge Health Plan Ltd. Norwich, UK). One day's supply (3 meals/day) provides an intake of polyphenols equivalent to 0.5 L red wine/day.

0.5 g of total polyphenol pool obtained from red wine is added to 250 ml plain yoghurt containing strawberry flavour and sweetener. The red coloured polyphenol material enhances the appearance of the yoghurt, and provides a highly palatable foodstuff with health benefits.

The following formulation is that of a non-alcoholic drink provided as a powder to be mixed with water.

53 g of the powder is dissolved in 1 liter of water. A serving of 250 ml provides 0.75 g of active polyphenols.

The following is an alcoholic drink provided as a bottled ready-to-drink mix.

The polyphenol is dissolved in the flat (deaerated) tonic mix and then gassed with carbon dioxide under pressure to give an aerated drink. Aliquots of 450 ml are dispensed into bottles, the vodka added and the bottle sealed with a screw cap.

About 2000 Kg pomace obtained from white grapes was well stirred in a commercial mixer with 2500 L distilled water at 30.degree. C. for four hours. The mixture was then removed from the mixer and placed in a tank and allowed to settle for two hours, the supernatant was then drawn off and filtered to give a clear liquid. The same procedure was then employed as in example 1 or absorption of the polyphenols on the resin using similar quantities of Diaion HP-20 resin and eluting solvent.

On concentration of the aqueous ethanol solution to 35% dry matter a red coloured solid appeared weighing approximately 600 g. This was soluble in 10% aqueous alcohol and was then spray dried to give a solid insoluble in water but soluble in aqueous alcohol. The remaining solution was then spray dried under nitrogen to give 1.4 Kg of a red coloured material containing about 50% polyphenols. The composition of this was similar to that obtained in example 1.

This method has the disadvantage that the procedure to obtain the extract before absorption on the resin is more difficult and time consuming. Although the yield is less, the availability of grape skins cheaply has commercial advantages.

The powdered drink was reconstituted and administered to 5 volunteers for two weeks according to the protocol described in example 2. The results in the copper catalysed LDL oxidation assay were as follows:

It is concluded that an extract from grape skins (in this case white grapes), i.e. pomace, could be an effective antioxidant when taken orally for 2 weeks.

Plasma LDL (from the cohort of volunteers described in example 2) was separated by ultracentrifugation and dialysed against phosphate buffer as described in example 2. Polyphenol containing substances were analysed for their polyphenol content by the method of Singleton & Rossi (1965). Plasma LDL (0.05 .mu.g, LDL in 1.0 ml) was incubated with 100 .mu.l copper sulphate solution (final concentration 5 .mu.M) at 37.degree. C. and the lag time determined by the copper catalysed diene assay, as described in example 2. T.the ability of the polyphenol containing substances to prolong the lag time in vitro was determined by adding 4 .mu.g of polyphenol substance to 1 ml of LDL prior to the addition of the copper sulphate. The substances tested were as follows:

1) Cabernet Sauvignon red wine

2) Vin ordinaire white wine

3) Red wine polyphenols, prepared as described in example 1

4) Sefcal.TM. anthocyanin, as described in example 2

5) Endotclon.TM. proanthocyanidins, as described in example 2

6) French Paradox capsules (red wine marc), as described in example 2

7) Polyphenon.TM. (green tea catechins), as described in example 2

The results obtained in vivo by oral consumption of the test substances for 2 weeks are compared with the in vitro results in Table 7 below. The in vitro results are a mean of four determinations. The lag time was increased with all substances added at a level of 4 .mu.g/ml. The order of the magnitude of effect observed was: polyphenol powder=anthocyanins>green tea catechins>grape seed proanthocyanidins>red wine>white wine>red wine marc.

When the substances were taken orally and LDL separated and tested as described in example 2, only red wine and red wine polyphenols gave a prolongation of the lag time, all the other polyphenol containing substances were inactive. This clearly shows that it is impossible to predict the in vivo effect of a substance from in vitro results. The lack of activity of most of the substances in vivo might be due to their lack of absorption from the gut, or failure to be incorporated into LDL.

Twenty of the above mentioned volunteers from example 2 were divided into groups (A and B) of 6-9 subjects and were given for two weeks:

A) A blackcurrant flavoured drink (330 ml) containing 1 g total red wine polyphenols and mixed with a commercially available powder (sugar, citric acid, sodium citrate aspartame, synthetic flavour; Cambridge Manufacturing Co Ltd, Corby, UK) to which water was added immediately prior to consumption; or

B) Capsules containing red wine polyphenol powder as prepared above in a dose of 2 g red wine polyphenols/day.

The products were divided equally and taken after lunch and dinner.

Plasma samples were obtained and spun in an ultracentrifuge to obtain LDL as described in Example 2.

Three methods of treating the LDL before oxidation were employed as below.

Final dialysis without EDTA.

LDL was dialysed with 10 mM phosphate buffer saline containing 2 .mu.M EDTA for one hour using a dialysis cassette. (Pierce Slide-A-Lyzer Perstorp Biotec Company, USA) at 4.degree. C. for one hour, then with 10 mM phosphate buffer saline overnight.

b) Continuous dialysis with EDTA

LDL was removed and dialysed at 4.degree. C. as above except that dialysis throughout was with 10 .mu.M EDTA in 10 mM phosphate buffered saline.

c) Column treatment

LDL was passed through an EcNo-pac 10DG desalting column (Bio-Rad Labs, UK). The column was washed twice with treated 10 mM PBS [chelex-100 resin (Bio Rad, UK), 5 g/L PBS mixed and decanted]. 600 .mu.L LDL was then loaded on the column and eluted with 3 ml PBS buffer at a flow rate of 0.6 ml/min using an Ismatec IPC Peristaltic pump (Ismatec, Weston Super Mare, UK).

Copper catalysed peroxidation was then performed and the lag time measured as in example 2. The results are shown in Table 7.

Red wine polyphenol consumption either as a drink (1 g/day) or capsules (2 g/day) produced an increase in lag time (when EDTA was omitted from the final dialysate) of 30% and 21% respectively and also by the column method of 12% and 22% respectively. The addition of EDTA in the dialysate abolished the effect with 1 g/day red wine polyphenols and gave only a small increase in lag time of 7% with 2 g/day.

It is another object of the invention to provide an active flavonol preparation for the treatment of coronary heart disease and other diseases associated with smooth muscle cell proliferation such as atherosclerosis, restenosis, stroke and neoplasias of the bowel and uterus, uterine fibroid or fibroma.

The inventors have surprisingly found that it is possible to prepare a flavonol composition (e.g. from red wine) which when given orally to a human subject will stimulate the production of total and active TGF-.beta.-1.

It has been demonstrated that when red wine or a preparation of flavonols obtained from red wine provided as a powder or a drink are administered orally to man there is an increase in plasma total and active TGF-.beta.-1. White wine which contains little flavonols is inactive.

The dosage of flavonol preparation is dependent on the degree of activity of the material but will be between 10 mg and 10 g per day. For the total polyphenolic pool obtained from wine the preferred dose is 0.1-4 g/day and more preferably 1-2 g/day equivalent to 0.5 to 1 liter of red wine per day.

Red wine, white wine and a preparation of polyphenols obtained from red wine (as described previously in example 1) in the form of a powder or drink given by oral administration to human subjects, have been studied for their effects on plasma TGF-.beta..

Healthy volunteers (30 men aged 35 to 65 years) were asked to discontinue wine consumption for two weeks. They were given either 375 ml of red wine or white wine or 1 g total pool of red wine polyphenols (prepared from the same Cabernet Sauvignon wine as above) either as capsules or as a flavoured drink in 330 ml water. Each supplementation was consumed twice daily after meals for a period of two weeks.

Blood samples were drawn into K.sub.3 EDTA (1 mmol/L) after treatment and centrifuged to obtain the plasma, which was stored at -70.degree. C. prior to analysis. Total plasma polyphenols were measured by the method of Singleton and Rossi (1965). Total TGF-.beta.-1 was determined by immunoassy using two different polyclonal antibodies (methods 1 & 2, described below):

Method 1

Total (latent+active) TGF-.beta. was measured by a Quantikine.RTM. human TGF-.beta. immuno assay kit supplied by R&D systems (Abingdon, Oxford, UK). This assay employs the quantitative sandwich immunoassay technique. TGF-.beta. soluble receptor type II binds TGF-.beta.-1 which has been precoated on a microtitre plate. Standards and samples are pipetted into the wells and any TGF .beta. 1 present is bound by the immobilized receptor. After washing away any unbound substances an enzyme linked polyclonal antibody specific for TGF-.beta.-1 is added to the wells to sandwich the TGF-.beta.-1 immobilized during the first incubation. Following a wash to remove unbound antibody enzyme reagent a substrate solution is added to the wells which produces a colour with the enzyme. The intensity of the colour developed is proportional to the TGF-.beta.-1 present.

Before carrying out the assay, latent TGF-.beta. is converted into the active form by adding acetic acid and urea, incubating for 10 minutes and then neutralising with sodium hydroxide/HEPES solution. The method estimates (latent+active) TGF-.beta.-1. Activation of latent TGF .beta. was performed as follows: to 0.1 ml of plasma, 0.1 ml of 2.5 N acetic acid/10 M urea was added, mixed well and incubated for 10 minutes at room temperature. To this solution 0.1 ml of 2.7 N NaOH/1 HEPES was added to neutralise the sample, and mixed well. Prior to assay the activated plasma sample was diluted 10-fold with calibrator diluent serum RD6M supplied by the kit manufacturer.

The assay procedure was as follows: 200 .mu.l of sample or standard was added to each well of the microtitre plate. The plate was then covered with an adhesive strip of plastics material and incubated for 3 hours at room temperature. Each well was then aspirated and washed three times with 400 .mu.l of washing buffer. 200 .mu.l of TGF-.beta.1 conjugate was then added to each well and the plate again covered with a fresh adhesive strip and incubated at room temperature for 110 minutes. Wells were then aspirated and washed three times with 400 .mu.l of washing buffer. 200 .mu.l of substrate solution was added to the wells and the plate incubated for 20 minutes at room temperature. 50 .mu.l of 2 N H.sub.2 SO.sub.4 solution was then added to each well and the optical density measured at 450 nm.

Method 2

Essentially the same method was employed as above except that TGF-.beta. was not activated before estimation, and instead of the polyclonal antibody for TGF-.beta.-1 a BDA-19 antibody (R&D systems, Abingdon, Oxford, UK) was used instead. This method estimates an active form of TGF-.beta.-1.

Preferably, consumption of a composition in accordance with the invention will produce an increase of TGF-.beta.1 levels in the subject by at least 1.5 mg/ml as judged by Method 1, or at least 0.5 mg/ml as judged by Method 2.

Results

As shown in Table 8, plasma polyphenols were increased in red wine but not with white wine, and with the polyphenol capsules and drink. An increase in TGF-.beta.-1 was observed by both methods in red wine, and with the polyphenol capsules and drink but not white wine. This indicates that red wine polyphenols increase both the total amount (latent+active) TGF-.beta.-1 and of an active form of TGF-.beta.-1. It is concluded that wine polyphenols increase total TGF-.beta.-1 and have the potential to inhibit VSMC proliferation.

The inventors have additionally found surprisingly that it is possible to prepare a flavonol composition (e.g. from red wine) which when given orally to a human subject will inhibit platelet aggregation and stimulate fibrinolysis.

In particular it has been demonstrated that when a preparation of flavonols obtained from red wine is administered orally to man there is a decrease in platelet aggregation when arachidonic acid, ADP, collagen, or thrombin are used as agonists. Furthermore consumption of the polyphenol preparation increases tPA activity in the plasma of the subject.

The dosage of flavonol preparation is dependent on the degree of activity of the material but will be between 10 mg and 10 g per day. Where the composition comprises the total phenolic pool obtained from red wine the preferred dose in 0.1 to 4.0 g per day and more preferably 1 to 2 g, which is equivalent to 0.5 to 1.0 liter of red wine per day.

A red wine polyphenol composition was prepared as described previously (Example 1 above).

The diet of twelve healthy men aged 35 to 65 was supplemented with 2 g red wine polyphenols (as described in example 2) or aspirin (75 mg) daily for two weeks. Fasting citrated blood was collected as a baseline and at four hours and two weeks after commencement of the trial, as follows: blood was obtained from the antecubital vein, with the subject in the recumbent position, using minimal stasis, into a syringe containing 0.11 M citrate (1:9 v/v to blood). Platelet-rich plasma (PRP) was prepared by centrifugation of blood at 250 g for 10 minutes. Most of the PRP was removed and the platelet-poor plasma (PPP) was then prepared by centrifuging the residual blood at 2,500 g for 15 minutes. The concentration of platelets in the PRP was determined in a cell counter (Minos STX, ABX Ltd, Montpellier, France). Samples with a platelet count outside the range 150,000 to 350,000 per .mu.l were rejected. The PRP was allowed to rest for at least 30 minutes before commencement of the aggregation studies. The time between blood collection and platelet aggregation was never more than three hours.

Platelet aggregation was determined on the freshly prepared platelets using a PAP-4C aggregometer (BioData, Alpha Laboratories, Southampton, UK). A 200 .mu.l sample of PRP was added to a siliconised cuvette and incubated at 37.degree. C. for 3 minutes. Aggregation was induced by the addition of 20 .mu.l of the agonist (one of the following: arachidonic acid at 455 .mu.g/ml; 1.8 .mu.mol/L ADP; collagen at 43 .mu.g/ml obtained from BioData; thrombin at 0.11 U/ml, obtained from Sigma, Poole, Dorset, UK; all are final concentrations in the aggregation mixture). The platelet suspension was stirred at 1,000 rpm at 37.degree. C. for 5 minutes. Maximum aggregation (percent from baseline) was determined within this time. The value was a measure of the aggregatory potential of the platelets, a decrease indicating an anti-aggregatory response when comparing samples drawn before and after consumption of the test material. Statistical significance was assessed by paired the t-test.

The red wine polyphenol powder inhibited platelet aggregation either acutely or chronically as shown in Table 9. These effects are similar to but smaller than those observed with aspirin (75 mg per day), except for thrombin. In particular, the effect of the polyphenols on arachidonate-induced aggregation suggests an inhibition of platelet cyclo oxygenase activity. These results suggested that the red wine polyphenols have aspirin-like-effects, although there is an additional inhibitory effect on thrombin-induced aggregation.

The same trial was used to investigate levels of PAI-1 and tPA activity in the subjects. Blood was obtained from the antecubital vein, with the subject in the recumbent position using minimal stasis, into a syringe containing 0.5 M citrate, pH 4.3 (Stabilyte.TM., 1:9 v/v in blood). Plasma was prepared by centrifugation of blood at 2,500 g for 15 minutes at 4.degree. C. and frozen at -70.degree. C. immediately.

All three samples (baseline, 4 hours and 2 weeks) from a subject were quickly thawed at 37.degree. C. on the day of assay. tPA activities were determined using a commercially available kit (Chromolize.TM., from Biopool, Umea, Sweden) which is a bio-functional immunosorbent assay. Sample or standard (100 .mu.l) was added to each well. The microtitre plate was incubated in a plate shaker for 20 minutes, after which time the contents of the wells were discarded, and the wells washed 4 times. Next, 50 .mu.l of substrate solution was added to each well, followed by 50 .mu.l of plasminogen reagent, and the plate incubated for a further 90 minutes. Finally, 50 .mu.l of 1.7 M glacial acetic acid solution was added to each well and mixed for 15 seconds. Absorbances were measured at 405 nm, and the activity of tPA in the sample read from a linear calibration curve. The significance of the differences between baseline, 4 hour and 2 week values for each treatment was assessed by a two-tailed paired t-test. The results are shown in Table 10.

The enzyme tPA constitutes an important protein in the fibrinolytic pathway, and its activity is thought to play a major role in the fibrinolytic system. The physiological role of tPA is to activate plasminogen to plasmin, which degrades fibrin to soluble fibrin-degradation products. In the assay of tPA, the specific inhibitor PAI-1 is usually present in a large excess and must be prevented from quenching tPA activity. This is provided for by use of Stabilyte.TM. blood collection tubes, which provide mild acidification of the sample.

Because of PAI-1 values are known to be subject to diurnal variation, and additional trial was carried out in which the same subjects were studied using water as a placebo, instead of red wine polyphenols. The results are shown in Table 11.

Red wine polyphenols (2 g/day) produced a significant decrease in PAI-1 after 4 hours which was associated with a significant increase in tPA activity (table 10). No changes were seen after an overnight fast after 2 weeks' treatment. However, as shown in table 11, after 4 hours PAI-1 antigen concentration is decreased after administration of water, indicating that the effects on PAI-1 antigen concentration observed following polyphenol powder consumption were simply due to diurnal variation. Administration of water did not significantly increase tPA activity however, whilst red wine polyphenol powder gave a 2.7 fold increase in tPA activity. It is concluded that red wine polyphenols produce a beneficial effect in stimulating fibrinolysis by increasing tPA activity, but have no effect on PAI-1 antigen concentration. tPA promotes the formation of plasmin from plasminogen and plasmin converts the latent form of TGF-.beta. into its active form which then inhibits the growth of vascular smooth muscle cells (VSMC) which contribute to the growth of atherosclerotic plaques.

Preferably consumption of a composition in accordance with the invention will cause at least a 2% reduction in maximum platelet aggregation (as determined by the method described above) and/or an increase in tPA activity of at least 0.75 U/ml (as determined by the method described above).

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