Title:  Methods for treating or reducing prediposition to breast cancer, pre-menstrual syndrome or symptoms associated with menopause by administration of phyto-estrogen

United States Patent:  6,562,380

Issued:  May 13, 2003

Inventors:  Kelly; Graham Edmund (Northbridge, AU)

Assignee:  Novogen Research Pty Limited (New South Wales, AU)

Appl. No.:  910837

Filed:  August 13, 1997

Phyto-estrogen-containing health supplement compositions containing any two or more of Genistein, Daidzein, Formononetin and Biochanin A, or the natural glycosides thereof are administered for treating or reducing predisposition to breast cancer, pre-menstrual syndrome or symptoms of menopause.

DISCLOSURE OF INVENTION

The present invention concerns a health supplement specifically enriched for isoflavones selected from genistein, daidzein, formononetin and biochanin A, or their natural glycoside form, or their analogues, in sufficient amounts to improve the health of a human.

Preferably the supplement contains an excipient, a diluent, a carrier or the like, or else the supplement is mixed with food or can be consumed directly. It is also preferred that foodstuffs, are readily available, have no known toxic components, and are rich sources of isoflavones; such foodstuffs preferably being red clover or soya. It is also preferred that the ratio of genistein and/or it methylated derivative biochanin A to daidzein and/or its methylated derivative formononetin is between 1:2 to 2:1. Other plant components with oestrogenic activity including lignans, coumestans and flavones may also be present in the extract, but it is held that these are of secondary importance to the predominant isoflavones. The term phyto-oestrogens is used hereafter to indicate a predominance of isoflavones with lesser amounts of lignans, coumestans and flavones.

The invention also concerns a method of improving the health of a human by administering to the human a sufficient amount of phyto-oestrogen. Ideally, the phyto-oestrogen is administered regularly on a daily basis over a sufficient period such as at least a month. The health conditions which may be prevented or ameliorated include cancer of the breast, cancer of the prostate, cancer of the uterus, cancer of the bowel, benign (or cystic) breast disease, pre-menstrual syndrome (also known as pre-menstrual tension), or adverse symptoms associated with menopause in women. The method and supplement in accordance with the invention also improves the health of a human having elevated levels of blood cholesterol. The product also is useful in avoiding or ameliorating cancer in persons. The symptoms produced by these conditions and the general well-being is also improved by the use of these supplements

The phyto-oestrogen in accordance with the invention may be obtained from a number of different sources. Preferably the phyto-oestrogens are extracted from a clover such as red clover or subterranean clover or from soya which contain high levels of phyto-oestrogens. However, any source rich in phyto-oestrogens may be used instead, if desired.

Various different isoflavones have been identified from these sources - they are principally genistein, biochanin A, daidzein, formononetin and glycitein. In plants these compounds occur principally in a glycoside form bound to sugars such as glucose, with smaller amounts present as the aglucone forms. The formulae of the isoflavones are: ##STR1##

The structure of biochanin A is the same as for genistein but with a 4'-methoxy group, and similarly formononetin has the same structure as daidzein, but with a 4'-methoxy group.

Following ingestion by humans, the glycosidic isoflavones are hydrolysed to the aglucone form and biochanin A and formononetin are demethylated by bacterial fermentation to genistein and daidzein respectively. A small proportion of these free isoflavones are absorbed directly from the bowel and circulate in the blood. The bulk of the isoflavones, however, remain in the bowel and undergo fermentation to form various metabolites which also are absorbed into the bloodstream. The principal metabolites which have been identified are equol and O-desmethylangolensin.

In vitro and in vivo studies have indicated that genistein, biochanin A, equol, daidzein, formononetin all have oestrogenic activity in descending order. O-desmethylangolensin is only very weakly oestrogenic and glycitein is non-oestrogenic.

In animal and in vitro studies, genistein has been shown to have greater oestrogenic/anti-oestrogenic activity and SHBG-stimulating capacity than the other isoflavones or their metabolites (approximately 10 times that of daidzein and formononetin). However, the full range of biological effects of the different isoflavones have yet to be fully determined, and in particular their relative efficacies in the different biological effects such as oestrogenicity, hypocholesterolaemia, anti-angiogenesis, anti-oxidation, anti-carcinogenesis for example are not yet fully known.

It is thought that because the methyl forms (biochanin A and formononetin) ultimately are largely demethylated to their principals, genistein and daidzein, with improved biological efficacy, then it is unimportant whether the isoflavones are present in the claimed product in the methylated or demethylated forms.

Given that the relative biological importance of the two isoflavone groups (being genistein and daidzein) to human health remains unclear, and that each might indeed have different importance, plus the fact that both isoflavones are present in the diet in approximately equal proportions, then it is prudent that both isoflavones be present in the claimed product in approximately equal proportions.

Any leguminous plants such as detailed here could be used as sources of phyto-oestrogens (principally isoflavones with lesser amounts of lignans and coumestans): Indian liquorice (Abrus precatorius); various species of Acacia spp. including, A. aneura, A. cibaria, A. longifolia, and A. oswaldii; ground nut (Apio tuberosa); ground pea (Arachis hypogea); milk vetch (Astragalus edulis); marama bean (Bauhinia esculenta); sword bean (Cajanus cajan indicus); jack bean (Canavalia ensiformis); sword bean (Canavalia gladiata); seaside sword bean (Canavalia rosea); various Cassia spp. including C. floribunda, C laevigata, and C. occidentalis; carobbean (Ceratonia siliqua); chick pea (Cicer arietinum); yebnut (Cordeauxia edulis); various Crotalaria spp. including C. laburnifolia, and C. pallida; cluster bean (Cyamopsis psoralioides); tallow tree (Detariaum senegalense); sword bean (Entada scandens); balu (Erythrina edulis); soyabean (Clycine max); inga (Ingaedulis); Polynesian chestnut (Inocarpus fagifer); hyacinth bean (Lablab purpureus); grass pea or Indian vetch (Lathyrus sativus); cyprus vetch (Lathyrus ochrus); lentil (Lens culinaris); jumping bean (Leucaenal eucocephala); various Lupinus spp. including L. albus, L. luteus, L. angustifolium, L. mutabilis, and L. cosentinii; ground bean (Macotylma geocarpa); horse gram (Macrotyloma uniflorum); alfalfa (Medicago sativa); velvet bean (Mucuna pruriens); yam beans (Pachyrhyzuz erosus, P. tuberosus); African locust bean (Parkia clappertoniana); Parkia speciosa; oil bean tree (Pentaclethra macrophylla); various Phaseolus spp. including P. acutifolius, P. vulgaris, P. luntus, P. coccineus, P. adenathus, P. angulris, P. aureus, P. calcaratus, P. mungo, and P. polystachyus; garden pea (Pisum sativum); djenko bean (Pithecolobium lobatum); mesquite (various Prosopis spp.); goa bean (Psophocarpus scandens, P. tetragonolobus); various Psoralea spp.; Sesbania bispinosa; yam bean (Sphenostylis stenocarpa); tamarind (Tamarindus indica); fenugreek (Trigonella foenum-graecum); vetches (various Vivia spp. including V. sativa, V. atropurpurea, V. ervilia, and V. monantha); broad bean (Vicia faba); black grani (Vigna mungo); various Vigna spp. including V. radiata, V. aconitifolia, V. adanatha, V. angularus, V. tribolata, V. umbelata, and V. unguiculata; and, earth pea (Voandzeia subterranea).

The ideal sources of phyto-oestrogens for preparation of a supplement in accordance with the invention are preferably those which (i) are readily available, (ii) are relatively inexpensive, (iii) are readily and economically processed so as to yield the extract, (iv) have a high isoflavone content so as to provide high yields, and (v) have no known toxic components requiring selective removal or inactivation.

Certain clovers, such as red clover (T. pratense) and subterranean clover (T. subterranean) are the preferred sources. On a dry weight basis, these clovers contain the highest amounts of oestrogenic isoflavones of all legumes tested to date with levels of 3-5 g % (T. subterranean) and 1-3 g % (T. pratense). In comparison, soya flour has a level of 0.15-0.30 g %, lentils (0.08-0.12 g %), chick peas (0.07-0.13 g %), and garden peas (0.02-0.03 g %). Thus it can be seen that clovers contain approximately at least 10-30 times by weight the isoflavone content of other commonly available, human leguminous foodstuffs meaning that for manufacturing purposes, the yield of isoflavones per unit weight of plant material is many times greater from clover than from other legumes.

Red clover and subterranean clover also are common fodder crops and are readily grown and are widely available. Clovers also are comparatively cheaper ($200/tonne) than crops such as soya and lentils ($500/tonne).

With clovers, the isoflavones are recovered from the leaf rather than from the seed in the case of soya, beans, nuts and grams. This provides a substantially higher yield of isoflavones per unit area of pasture for clovers compared to other legumes because of the greater leaf matter compared to seed matter recovered per plant.

Clovers also have an extended growing season, and faster growth rates compared to those legumes such as soya, lentils or chick peas where the seed is the end-product. Clover can be cropped for its leaf content repeatedly over a single growing season. An additional benefit of this is that as phyto-alexins, the isoflavone content increases in response to the stress of cropping.

Thus it can be seen that in clovers versus other legumes provide a combination of (a) higher isoflavone content per dry weight of plant, (b) a higher yield of dry matter containing isoflavones per plant, and (c) a higher yield of dry matter per hectare.

An additional feature of clovers is that there are wide varieties of cultivars with widely differing isoflavone levels and types. This allows blending of different cultivars to achieve the desired ratio of the different isoflavones, although it is equally possible to use a single cultivar which provides the desired ratio.

Other legumes such as soyabean flour may be used for enrichment of phyto-oestrogens but the substantially poorer (approx. 10%) yield of isoflavones compared to clovers means that the manufacturing costs are substantially greater and there is substantially greater amounts of waste products which requires disposal or further treatment for re-use as a foodstuff. An alternative, however, to the use of whole soya for this purpose, is to use the hull, and hypocotyl (or germ) of the whole soyabean. The hull and hypocotyl represent only a small proportion by weight (8% and 2% respectively) of the intact bean. However, the coumestrol content of soya is concentrated in the hull, and the daidzein content of soya is concentrated in the hypocotyl. The two cotyledons which comprise the bulk of the soyabean (90% by weight) contain the bulk of the genistein content of soya. During standard processing of soyabeans, the hulls being a fibrous component with little or no perceived nutritional value normally are separated and removed by physical means. The hypocotyls become separated following the splitting of the cotyledons, and while these currently generally are not deliberately isolated, they may be separated and isolated by passing the disturbed soyabeans over a sieve of sufficient pore size to selectively remove the small hypocotyl. The hypocotyl contains approx. 1.0-1.5 g % isoflavones (95% daidzein, 5% genistein). The raw hypocotyl and hull material can be ground or milled to produce, for example, a dry powder or flour which then could be either blended or used separately as a dietary supplement in a variety of ways including, for example, as a powder, in a liquid form, in a granulated form, in a tablet or encapsulated form, or added to other prepared foodstuffs. Alternatively, it could be further processed to yield an enriched extract of phyto-oestrogens. Either or both of these materials also could be added to other leguminous material such as clover to provide the invention.

In plants, the oestrogenic isoflavones are restricted principally to the leaf, fruit and root; the stem and petiole contain very little. With soya and other common human legume foodstuff crops, the leaves are rarely regarded as foodstuff, indeed with these crops, the plants normally are allowed to die and dry out before the seed crop is harvested. Nevertheless, the fresh leaves of these crops could be regarded as a source of phyto-oestrogens for the invention although the much lower isoflavone content of the leaves of these crops compared to clovers, plus their generally slow growth compared to clovers, suggests that they would not be a preferred source of large-scale isoflavone enrichment.

To provide a similar amount of isoflavone to that contained in most traditional legume-rich diets (50-100 mg oestrogenic isoflavones/day) would require an average daily consumption of 3-6 g dry weight or 15-30 g wet weight of specially selected cultivars of clover with particularly high isoflavone levels. Clover grasses generally are not eaten by humans, except to a limited extent as sprouts of some of the pleasanter tasting varieties. Isoflavones are intensely astringent and are responsible in large part for the bitter taste of legumes. Thus the types of bean sprouts, clover sprouts and alfalfa sprouts generally available have been selected on the basis of cultivar and of age for pleasant taste, and in so doing inadvertently have been selected for low isoflavone content. Of the sprouts currently available in Western countries for human consumption, between approx. 100-250 g would need to be consumed daily to provide a dosage of 50-100 mg isoflavones. Certainly clovers and other legume sprouts are not generally eaten in such sufficient quantities by humans to obtain the advantages of the present invention.

The invention also concerns formulations containing the phyto-oestrogens discussed above together with a dietary suitable excipient, diluent, carrier, or with a food. Ideally the formulation is in the form of a pill, tablet, capsule, or similar dosage form

The formulations may be a variety of kinds, such as nutritional supplements, pharmaceutical preparations, vitamin supplements, food additives or foods supplemented with the specified active phyto-oestrogens of the invention, liquid or solid preparations, including drinks, sterile injectable solutions, tablets, coated tablets, capsules, powders, drops, suspensions, or syrups, ointments, lotions, creams, pastes, gels, or the like. The formulations may be in convenient dosage forms, and may also include other active ingredients, and/or may contain conventional excipients, carriers and diluents. The inclusion of the subject phyto-oestrogens in herbal remedies and treatments is also a preferred part of the invention.

The invention is also directed to the amelioration, prevention, or of various conditions responsive to treatment with the phyto-oestrogen substances of the invention. The preferred amounts to be administered to the human fall within 20-200 mg on a daily basis. More preferably the dosage is from 50-150 mg on a daily basis, and most preferably at a dosage of about 100 mg. If desired greater dosages can be administered for therapeutic reasons. In contrast to prior practices such high dosages were not possible. For example, dosages of up to or greater than 1000 mg may be suitable to treat some conditions. In order to obtain the benefits of the invention, the treatment with the isoflavones should continue for a considerable period, ideally for at least a month, and ideally continuously for the whole period for which the health improvement advantages should accrue.

The product according to the present invention yields a constant and accurately known amount of isoflavones. The product is also ideally a natural product, which has advantages for consumer acceptance, and in accordance with the supposed theory behind the invention may very possibly be one of the main causes for its beneficial effects. Whole legumes have a widely variable isoflavone content due to two main causes: the type of legume and the environmental effect. The type of legume typically has a wide range of isoflavone content. The miligram of isoflavone per hundred gram of whole foodstuff (dry weight) is given in the following table:

Thus common leguminous foodstuffs consumed in Western countries (broad beans, garden peas etc) have relatively low oestrogenic isoflavone content and exceptionally large amounts of these would need to be consumed daily to approximate those isoflavone levels consumed in traditional diets. Most Western cultures do not traditionally eat legumes with high isoflavone contents, and those soya products (milk, tofu etc) which are becoming increasingly popular in Western countries, also have relatively low isoflavone levels compared to whole soya, indicating that relatively large amounts of these would need to be consumed on a regular basis to deliver the required isoflavone levels.

The enviromental effect arises because the isoflavone levels in any species of plant depend greatly on the age of the plant, the climatic conditions where it is grown, the fertiliser and so forth. Therefore constant and consistant dosage is very difficult with ordinary whole foodstuffs. The accurately determined quality and quantity of the active isoflavones in the product, and its easy consumability when compared with the almost impossible task of eating huge amounts of often practically inedible foods, is therefore an import feature of the invention for preventing and helping in overcoming various health problems.

Among the various health problems, the treatment or prevention of high blood cholesterol levels, and the treatment of PMS and menopausal symptoms is especially important. The product of the invention modulates the production and/or function of endogenous sex hormones in humans to modify or produce health improving effects, including the following: (i) lowered levels of various blood lipoproteins including, for instance, low-density and very-low-density cholesterol leading to reduced risk of development of atherosclerosis; (ii) reduced risk of development of cancer of the prostate; (iii) reduced risk of cancer of the breast; (iv) reduced risk of development of cancer of the uterus; (v) reduced risk of development of cancer of the large bowel; (vi) reduced risk of development of the syndrome in women commonly referred to pre-menstrual syndrome (PMS), which includes pre-menstrual tension (PMT); (vii) reduced risk of development of many untoward symptoms (including dry vagina, peripheral flushing, depression etc) commonly associated in women with menopause; and for treating benign breast disease in women (benign or cystic breast disease associated with non-malignant swelling and tenderness of breast tissue). The invention therefore is directed to a method for the prophylaxis or treatment of a human, to combat conditions associated with phyto-oestrogen deficiency, which comprises administering to the human an effective amount of phyto-oestrogen principally isoflavone but which might also include relatively smaller amounts of lignans and coumestans, ideally in a concentrated form, wherein the isoflavones include genistein, and/or biochanin A, and/or daidzein, and/or formononetin.

Cancer of the breast generally is considered to be associated with oestrogenic dysfunction. Breast cancer cells may display more oestrogen receptors than normal breast cells and stimulation of these receptors by endogenous oestrogens is thought to be a prime source of stimulation of their malignant growth. Currently synthetic anti-oestrogens are being used to prevent or treat the growth of malignant breast cells. Isoflavones are potent anti-oestrogens that could be expected to help prevent or to successfully treat breast cancer. It has been reported that the risk of breast cancer in western societies is indirectly proportional to the level of phyto-oestrogens in the diet and to the amounts of phyto-oestrogen metabolites excreted in the urine.

Cancer of the prostate generally is considered to be associated with sex hormone dysfunction and the growth of prostatic cancer cells is influenced by oestrogens and androgens. The incidence of prostatic cancer is low in communities with high legume intake and, conversely, is high in Western socieites. Phyto-oestrogens are though to protect from development of prostatic cancer. One mechanism may be the effect of phyto-oestrogens on lowering the proportion of unbound:bound reproductive hormones in the blood. However, there is other evidence to suggest that phyti-oestrogens, particularly isoflavones, can have a direct influence on certain cellular enzymes within prostatic cells.

Pre-menstrual syndrome has uncertain aetiology and pathogenesis, although most certainly is associated with reproductive hormone dysfunction. It also is a syndrome which has reportedly lower incidence in communities maintaining traditional high-legume diets. It is proposed that phyto-oestrogens will alleviate this condition by restoring balance to oestrogen metabolism.

Menopausal syndrome is associated with changes in the oestrogen profile in the body with advancing age. Adverse clinical symptoms may be treated with oestrogen replacement therapy. There is evidence that foodstuffs high in phyto-oestrogens are a suitable alternative to synthetic hormones in this respect, producing alleviation of adverse clinical symptoms. Again, it is proposed that phyto-oestrogens will function by restoring balance to oestrogen metabolism.

Benign (or cystic) breast disease has unknown aetiology. However, its association in women with certain stages of the menstrual cycle is strongly suggestive of oestrogen dysfunction. There currently is no successful treatment of this condition. Phyto-oestrogens are proposed to successfully treat this condition by restoring balance to oestrogen metabolism. Atherosclerosis is associated with cholesterol metabolism which in turn is associated closely with oestrogen metabolism. The generally higher incidence of atherosclerosis in young men versus young women, the rising incidence in women following menopause, and the lower incidence in post-menopausal women receiving oestrogen replacement therapy, all point to the moderating influence of oestrogens on cholesterol metabolism. A prime effect of oestrogens on cholesterol metabolism is stimulation of the liver to process cholesterol, particularly the highly atherogenic low-density lipoproteins and very low-density lipoproteins, into bile salts. It is proposed that phyto-oestrogens have an important hypocholesterolaemic effect in humans. There may be a variety of mechanisms involved, but one may be the stimulation by phyto-oestrogens of cholesterol catabolism by the liver.

Claim 1 of 23 Claims

What is claimed is:

1. A method for treating or reducing the predisposition to at least one condition selected from the group consisting of pre-menstrual syndrome or symptoms associated with menopause, said method comprising administering to a subject having said at least one condition a therapeutically effective amount of a phytoestrogen-containing health supplement composition, said phytoestrogen being extracted from soya or clover and comprising any two or more members of the group consisting of Genistein, Daidzein, Biochanin A, Formononetin or the natural glycosides of any of said phyto-estrogens.
 

____________________________________________
If you want to learn more about this patent, please go directly to the U.S. Patent and Trademark Office Web site to access the full patent.