Evaluation of estrogenic and androgenic activity of butylated hydroxyanisole in immature female and castrated rats

We evaluated the estrogenic and androgenic activity of butylated hydroxyanisole (BHA) using immature rat uterotrophic assay and Hershberger assay. To investigate (anti-) estrogenicity, BHA alone or with 17β-estradiol was administered to 20-days-old immature female rats for three consecutive days. Absolute and relative uterine weights were significantly decreased by BHA (50, 100, 250, 500 mg/kg) alone and 17β-estradiol-stimulated weights of uterine and vagina were also decreased by BHA (500 mg/kg), while uterine epithelial cell height was not affected. In Hershberger assay, BHA alone or with testosterone propionate (TP) was administered daily to 51-days-old castrated male rats for 10 days. BHA alone or with testosterone propionate (TP) caused no significant effect on androgen-dependent accessory sex organ weights; seminal vesicle/coagulative glands, glans penis, Cowper's gland, ventral prostate gland and levator ani plus bulbocarvernosus muscle. Although, the relative weight of ventral prostate gland was increased by the co-treatment of BHA 250 mg/kg with TP 0.4 mg/kg compared to that of TP alone, the relative and absolute weights of other androgen-dependent organs and absolute and formalin-fixed ventral prostate gland weight showed no changes. Our studies suggest that BHA have anti-estrogenic activity for the decrease of uterine weight in immature female rat but have negligible effect on the androgenic activity in castrated male rats.