Comparative study of concentration of isoflavones and lignans in plasma and prostatic tissues of normal control and benign prostatic hyperplasia.
OBJECTIVE
Isoflavones and lignans are phytoestrogens that have recently gained interest as dietary factors related to prostatic diseases. However, no data on the concentrations in prostate tissue in humans is available. Therefore, the concentrations of isoflavones and lignans in plasma and prostatic tissues according to the prostate volume were compared to determine their possible effect on the benign prostatic growth.


METHODS
Fasting plasma and prostatic tissue specimens were acquired from 25 men over 50 years of age with similar normal dietary habits and no previous history of drug intake that could affect the isoflavones and lignans levels. The tissue was acquired either during a transurethral resection of the prostate in 15 patients with benign prostatic hyperplasia (BPH) with prostate volume over 40 ml or during a radical cystoprostatectomy in 10 patients with bladder cancer with a prostate volume < 25 ml, who were used as the controls. Quantitative analysis of the isoflavones, specifically equol, daidzein and genistein and lignans, particularly enterodiol and enterolactone, was performed by gas chromatography-mass spectrometry.


RESULTS
The mean prostatic concentrations of enterodiol, enterolactone, equol and daidzein in the BPH and the control groups were similar. However, the mean prostatic concentration of genistein was significantly lower in the BPH group than in the control group (65.43 +/- 17.05 vs 86.96 +/- 37.75 ng/ ml, respectively, p=0.032). The plasma concentration of isoflavones and lignans in the two groups were comparable.


CONCLUSIONS
Isoflavones, but not lignans, have some influence the benign prostatic growth, and the prostatic concentration of genistein possibly has the closest association among them. More studies to further clarify the roles and mechanisms of isoflavone action on BPH including pharmacokinetic studies are recommended.
Hong
Sung Joon
SJ
Department of Urology, Yonsei University College of Medicine, C.P.O. Box 8044, Seoul 120-752, Korea. sjhong346@yumc.yonsei.ac.kr
Kim
Sun Il
SI
Kwon
Soo Mee
SM
Lee
Jong Ran
JR
Chung
Bong Chul
BC
D001769:Blood / Q000378:metabolism*; D006801:Humans; D007529:Isoflavones / Q000378:metabolism*; D017705:Lignans / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D011467:Prostate / Q000378:metabolism*; D011470:Prostatic Hyperplasia / Q000378:metabolism*; D012016:Reference Values
D007529:Isoflavones; D017705:Lignans