Lignans and isoflavonoids in plasma
and prostatic fluid in men:
Samples from Portugal, Kong,
and the United Kingdom.
Morton MS Chan PSF Cheng C Blacklock N MatosFerreira
A AbranchesMonteiro L Hong Correia R Lloyd S Griffiths K
Prostate 1997 JUL 1;32(2):122-128
Morton MS, Univ Wales Coll Med, Tenovus Canc Res Ctr,
Dept Mass Spectrometry, Tenovus Bldg,
Heath Pk, Cardiff CF4 4XX, S Glam, WALES
BACKGROUND. Chinese men have lower incidences of prostate cancer compared to men from Europe and North America. Asians consume large quantities of soya, a rich source of isoflavanoids phyto-oestrogens and have high plasma and urinary levels of the se compounds. The mammalian lignans, enterolactone and enterodiol, are another group of weak plant oestrogens and are derived from seeds, cereals and grains. Vegetarians have high plasma and urinary concentrations of lignans. METHODS. The concentrations l ignans and isoflavonic phyto- oestrogens were determined by gas chromatography-mass spectrometry (GC-MS) in plasma and prostatic fluid from Portuguese, Chinese and British men consuming their traditional diets. RESULTS. In prostatic fluid the mean concent rations of enterolactone were 31, 162 and 20.3ng/ml for Hong Kong, Portugal and Britain respectively. Very high levels of enterolactone (>600ng/ml) were observed in the prostatic fluid of some of the men from Portugal.
Influence of isoflavones in soy protein
isolates on development of induced
prostate-related cancers in L-W rats.
Pollard M, Luckert PH
Nutr Cancer 1997;28(1):41-45
Pollard M, Univ Notre Dame, Lobund Lab,
Notre Dame,IN 46556 USA
Lobund-Wistar (L-W) rats are inherently susceptible to spontaneous and induced metastasizing adenocarcinomas in the prostate-seminal vesicle (P-SV) complex. L-W rats were fed soy protein isolates containing high isoflavones (genistein and daidzein ) or low isoflavones to determine their effects on development of induced P-SV tumors in two stages of the tumorigenic process. In rats fed the high- isoflavone-supplemented soy diet before initiation by methylnitrosourea (MNU), the incidence of induced p rostate- related cancer was reduced and the disease-free period was prolonged by 27% compared with rats fed the same diet but low in isoflavones. Rats fed the same diets, started after MNU, manifested suggestive bur less consistent results than those note d above. The incidence rates were of marginal significance, suggesting that the high intensity of the active induced disease may not represent the character of the slower-growing spontaneous (natural) disease. The delay of disease onset is of clinical significance.
Flavonoids, dietary-derived inhibitors
of cell proliferation and in vitro angiogenesis.
Fotsis T Pepper MS Aktas E Breit S Rasku
S Adlercreutz H Wahala K Montesano R Schweigerer L
Cancer Res 1997 JUL 15;57(14):2916-2921
Fotsis T, Univ Ioannina, Sch Med, Biol Chem Lab,
GR 45110 Ioannina, GREECE
Consumption of a plant-based diet can prevent the development and progression of chronic diseases associated with extensive neovascularization. Including solid malignant tumors. In previous studies, we have shown that the plant-derived isoflavonoid genistein is a potent inhibitor of cell proliferation and in vitro angiogenesis. In the present study, we report that certain structurally related flavonoids are more potent inhibitors than genistein, Indeed, 3-hydroxyflavone, 3',4'- dihydroxyflavone, 2',3'-dihydroxyflavone, fisetin, apigenin, and luteolin inhibited the proliferation of normal and tumor cells, as well as in vitro angiogenesis, at half-maximal concentrations in the low micromolar range. We have previously demonstrated that genistein concentrations in the urine of subjects consuming a plant- based diet is 30-fold higher than in subjects consuming a traditional Western diet. The wider distribution and the more abundant presence of flavonoids in the plant kingdom, together with the present results, suggest that flavonoids may contribute to the preventive effect of a plant-based diet on chronic diseases, including solid tumors.