Genistein administration decreases serum corticosterone and testosterone levels in rats.
The phytochemical flavonoid genistein has been shown to act as a potent competitive inhibitor of human adrenocortical 3beta-hydroxysteroid dehydrogenase and cytochrome P450 21-hydroxylase activities in vitro [J. Steroid Biochem. Molec. Biol. 2002; 80: 355-363]. In the present study, we evaluated the effects of large amounts of genistein continuously administered to weanling rats, particularly on steroidogenesis at the pubertal stage in vivo. Serum concentrations of free and total genistein were significantly higher in the 40 mg/kg genistein administration group when compared with the control group. In genistein administered rats, adrenal weight was significantly higher. Furthermore, a clear expansion of cells was observed in hematoxylin and eosin stained tissue at the zona fasciculata and zona reticularis of the adrenal cortex. However in the testis, no differences in weights or histologic changes were observed. Serum corticosterone concentration significantly decreased to 50% of control levels by 40 mg/kg genistein administration and testosterone also tended to decrease with this dose of genistein. On the other hand, although serum follicle stimulating hormone was unchanged, adrenocorticotropic hormone and luteinizing hormone levels increased with genistein administration. These results suggest a significant effect of genistein on steroidogenesis in the adrenal gland and testis of rats, and this effect appeared to be more evident on steroid production in adrenals than in testis in vivo.
Ohno
Shuji
S
Department of Biochemistry, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa, Tokyo 142-8501, Japan. ohno@hoshi.ac.jp
Nakajima
Yonako
Y
Inoue
Koichi
K
Nakazawa
Hiroyuki
H
Nakajin
Shizuo
S
D000311:Adrenal Glands / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D003345:Corticosterone / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D005640:Follicle Stimulating Hormone / Q000097:blood; D019833:Genistein / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007279:Injections, Subcutaneous; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011467:Prostate / Q000187:drug effects / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013737:Testis / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D013739:Testosterone / Q000097:blood*
D004791:Enzyme Inhibitors; D013739:Testosterone; D000324:Adrenocorticotropic Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D019833:Genistein; D003345:Corticosterone