Pharmacokinetics of isoflavones, daidzein and genistein, after ingestion of soy beverage compared with soy extract capsules in postmenopausal Thai women

Anupongsanugool, Ekasin; Teekachunhatean, Supanimit; Rojanasthien, Noppamas; Pongsatha, Saipin; Sangdee, Chaichan

doi:10.1186/1472-6904-5-2

Cited by 50 publications

(35 citation statements)

References 30 publications

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“…This was not unexpected since Epimedium brevicornum extract was about three orders of magnitude less potent than E 2 (Yap et al, 2005). Time point treatment interaction analyses indicated two peaks of bioactivity in sera of animals administered Epimedium brevicornum, consistent with human studies reporting a second flavonoid peak after consumption of soy foods (Anupongsanugool et al, 2005). This may be Animals were fed by gavage either vehicle, E 2 V (5 mg) or Epimedium brevicornum extract (500 mg) extract and blood collected at pre-determined time points for bioassays.…”

Section: Discussionsupporting

confidence: 82%

Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium

Yap

Shen

et al. 2007

Journal of Ethnopharmacology

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Section: Discussionsupporting

confidence: 82%

Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium

Yap

Shen

et al. 2007

Journal of Ethnopharmacology

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“…Whether these processing effects are relevant to humans is unknown, but there is certainly considerable reason for doubt. In humans, isoflavone pharmacokinetics appears to be similar in response to the consumption of soy foods and isoflavone supplements (116), and, with the exception of cholesterol reduction, the limited number of direct comparisons has shown similar effects of supplements and soy foods on health outcomes (117).…”

Section: Are Isoflavones Contraindicated For Some Women?mentioning

confidence: 99%

Perspectives on the soy–breast cancer relation

Messina

Wu²

2009

The American Journal of Clinical Nutrition

106

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There has been considerable investigation of the potential for soy foods to reduce risk of breast cancer. Initial enthusiasm for this research was partially based on the historically low incidence rates of breast cancer and high soy food intake in Japan. There are several putative soybean chemopreventive agents, but most cancer research has focused on isoflavones. Isoflavones possess both hormonal and nonhormonal properties relevant to carcinogenesis. Recent epidemiologic analyses indicate that among Asians high soy intake is associated with an approximate one-third reduction in the risk of both pre-and postmenopausal breast cancer. However, several lines of evidence suggest that to derive maximum protection against breast cancer, soy must be consumed early in life. This evidence is consistent with the lack of significant effects noted in clinical studies that have evaluated the effects of isoflavone-containing products on breast cancer risk markers. Isoflavones may exert their putative protective effects by stimulating breast cell differentiation in a manner similar to that which is thought to occur during early pregnancy. Finally, the ability of the isoflavone genistein to stimulate the growth of mammary tumors in ovariectomized athymic nude mice implanted with estrogen-sensitive breast cancer cells has raised concern that soy foods, and especially isoflavone supplements, are contraindicated for patients with breast cancer and women at high risk of breast cancer. However, findings from clinical studies, in which breast biopsies have been taken or breast tissue density measured after isoflavone exposure, are reassuring and contrast with the proliferative effects of conventional combined hormone therapy, although understanding of the effect of soy and isoflavones on breast tissues remains imprecise.Am J Clin Nutr 2009;89(suppl):1673S-9S.

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“…The increased plasma isoflavone levels in subjects given the isoflavone preparation is an important finding, as there have been several reports of significant variation in absorption of isoflavones in the literature and thus bioavailability (37)(38)(39)(40). Based on these controversial reports, we paid special attention to dose, multidose regimen to provide a consistent dose per day and the aglycone formulation of the purified isoflavones in this study.…”

Section: Discussionmentioning

confidence: 99%

A Phase II Randomized, Placebo-Controlled Clinical Trial of Purified Isoflavones in Modulating Steroid Hormones in Men Diagnosed With Localized Prostate Cancer

Kumar

Krischer

Allen

et al. 2007

Nutrition and Cancer

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Our purpose was to evaluate the safety and effectiveness of purified isoflavones in producing an increase in plasma isoflavones and a corresponding change in serum sex hormone binding globulin (SHBG) and steroid hormone levels in men diagnosed with early stage prostate cancer. In this Phase II randomized, double-blinded, placebo-controlled trial, 53 prostate cancer patients with a Gleason score of 6 or below were supplemented with 80 mg purified isoflavones or placebo for 12 weeks. Changes in plasma isoflavones, serum steroid hormones, and safety markers were analyzed from baseline to 12 wk. A total of 50 subjects completed the study. Although significant increases in plasma isoflavones (P < 0.001) was observed with no clinical toxicity, the corresponding modulation of serum SHBG, total estradiol, and testosterone in the isoflavone-treated group compared to men receiving placebo was nonsignificant. Increasing plasma isoflavones failed to produce a corresponding modulation of serum steroid hormone levels in men with localized prostate cancer. The study establishes the need to explore other potential mechanisms by which prolonged and consistent purified isoflavone consumption may modulate prostate cancer risk.

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Pharmacokinetics of isoflavones, daidzein and genistein, after ingestion of soy beverage compared with soy extract capsules in postmenopausal Thai women

Cited by 50 publications

References 30 publications

Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium

Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium

Perspectives on the soy–breast cancer relation

A Phase II Randomized, Placebo-Controlled Clinical Trial of Purified Isoflavones in Modulating Steroid Hormones in Men Diagnosed With Localized Prostate Cancer

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