Clover isoflavones

Black cohosh may cause nausea, vomiting, hypotension, and even miscarriage. It is absolutely contraindicated in pregnancy. Red clover contains coumarins and should therefore be avoided with anticoagulants. Diets high in red clover isoflavones have reduced livestock fertility and theoretically could do the same in humans. Flaxseed may cause nausea, diarrhea, and flatulence. Cyanogenic nitrates in flax (especially in immature seed pods) have produced toxic reactions. 

In a meta-analysis of clinical trials of monopreparations containing red clover isoflavones, the reviewers noted that there was no apparent evidence of adverse events during short-term use of red clover, but long-term studies were... 

Red clover contains isoflavones, compounds that are structurally similar to the human hormone estradiol and capable of binding to estrogen receptors (Umland et al. 2000). Some studies have indicated that red clover isoflavones have a greater affinity for the estrogen receptor P (found primarily in bone, brain, heart, and vascular system) than estrogen receptor a (found primarily in uterus, breast, ovaries, and adrenal glands) (Beck et al. 2005 Dornstauder et al. 2001). 

A second meta-analysis, including six placebo-con-trolled red clover isoflavone trials, with doses ranging from 40 to 80 mg daily, and study duration from 12 to 16 weeks, concluded that adverse events did not differ between isoflavone and placebo groups, although the events were not well characterized in several trials. Gastrointestinal symptoms were generally the most common adverse events in both isoflavone and placebo groups (Nelson et al. 2006). 

In women aged 35 to 70 with at least one first-degree relative with breast cancer, administration of 40 mg of red clover isoflavones daily for 3 years did not result in any significant differences in breast density, endometrial thickness, serum cholesterol, follicle-stimulating hormone levels, or bone mineral density, as compared to placebo. In postmenopausal women, some differences in bone marker levels were seen between active and placebo groups at 6 and 12 months (Powles et al. 2008). 

An extract of a red clover isoflavone preparation increased MCF-7 breast cancer cell proliferation rates (Bodinet and Freudenstein 2004). A standardized red clover isoflavone extract (9% isoflavones by dry weight) showed an affinity for both estrogen receptor (ER) a and P with a significantly stronger affinity for the ERP receptor in a yeast two-plasmid system (Dornstauder et al. 2001). 

An ethanolic extract of a commercial red clover preparation inhibited the drug-metabolizing isoenzyme CYP3A4 in a fluorometric microtiter plate assay (Budzinski et al. 2000). Genistein and daidzein, metabolites of the predominant red clover isoflavones biochanin A and formononetin, were shown to inhibit the enzyme CYPIBI (Roberts et al. 2004). 

Hale, G.E., C.L. Hughes, S.J. Robboy, S.K. Agarwal, and M. Bievre. 2001. A double-blind randomized study on the effects of red clover isoflavones on the endometrium. Menopause 8(5) 338-346. 

Hidalgo, L.A., P.A. Chedraui, N. Morocho, S. Ross, and G. San Miguel. 2005. The effect of red clover isoflavones on menopausal symptoms, lipids and vaginal cytology in menopausal women A randomized, double-bUnd, placebo-controlled study. Gynecol. Endocrinol. 21(5) 257-264. 

Powles, T.J., A. Howell, D.G. Evans, et al. 2008. Red clover isoflavones are safe and well tolerated in women with a family history of breast cancer. Menopause Int. 14(1) 6-12. 

Lam ANC, Demasi M, James MJ, Husband AJ, Walker C (2004) Effect of red clover isoflavones on cox-2 activity in murine and human monocyte/macrophage cells. NutrCtmcer49(l) 89-93... 

Based on these facts, in 2008, a group of Department of Biotechnology, University of Natural Resources and Applied Life Sciences Vienna, Vienna, Austria examined the possibility of biochanin A (pratensol, 41) and formononetin (biochanin B, pratol, 42) (Figure 10) as their ligands against the hiunan aryl hydrocarbon receptor. Then, for the purpose, it was tested whether or not biochanin A (pratensol, 41) and formononetin (biochanin B, pratol, 42) of two red clover isoflavones in the prescription for the improvement of the menopausal eomplaints could transactivate the aryl hydrocarbon receptor (AhR). 

Trifolium pratense (red clover)" Isoflavones Women s health, e.g., hot flushes... 

Sivesind, E. Seguin, R (2005). Effects of the environment, cultivar, maturity, and preservation method on red clover isoflavone concentration. Journal of Agricultural and Food Chemistry, 53,6397-6402. 

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