Biochanin A affects steroidogenesis and estrogen receptor-beta expression in porcine granulosa cells

摘要

Biochanin A, similar to other isoflavones, is present in soy and soy-based food, but predominantly in red clover. Red clover extract and biochanin A were reported to affect reproductive processes as well as to demonstrate menopause relief and anticancerogenic properties. Because porcine granulosa cells provide a suitable in vitro model for studying the intracellular mechanism of phytoestrogen action in the ovary, the objective of the study was to evaluate the in vitro effects of biochanin A on the following: (1) progesterone (P-4) and estradiol (E-2) secretion by granulosa cells, (2) viability of the granulosa cells, and (3) mRNA and protein expression of estrogen receptors alpha (ER alpha) and beta (ER beta) in the granulosa cells harvested from both medium (3-6 mm) and large (>= 8 mm) porcine ovarian follicles. RIA, alamarBlue assay, reverse transcriptase-polymerase chain reaction, and immunocytochemistry were used in the study to address the objectives. Biochanin A significantly inhibited P-4 and did not affect E-2 secretion by porcine granulosa cells regardless of the size of follicles that served as the source of the cells. Cell viability was not affected by the treatment. Biochanin A did not alter ER alpha and ER beta mRNA levels in the cultured porcine granulosa cells. In contrast, this isoflavone increased (P < 0.05) the immunoexpression of ER beta in the cells from both follicle types. In summary, biochanin A, similar to genistein and daidzein, affects follicular steroidogenesis and ER expression. Its effect on ER beta protein was more intense compared with other previously examined phytoestrogens