Effects of pterostilbene on treating hyperprolactinemia and related mechanisms

Hyperprolactinemia (HPRL) frequently causes primary menopause and reproductive disorders. Pterostilbene is known to have anti-inflammation and modulation on cell apoptosis. However, its role in treating HPRL and potential mechanisms remain unclear yet. Healthy female virgin SD rats were randomly assigned into control, HPRL model group, bromocriptine treatment group, and low (20 mg/kg) and high (40 mg/kg) pterostilbene treatment groups. All groups except control ones received metoclopramide hydrochloride injection for generating HPRL model. Uterus and ovarian index in all animals were monitored. Prolactin (PRL), estradiol (E2), follicle stimulating hormone (FSH) and luteinizing hormone (LH) were quantified by ELISA. Caspase 3 activity was assayed, with real time PCR measuring Bcl-2 and Bax mRNA levels. HPRL rats had lower uterus and ovarian index, accompanied with elevated PRL, caspase 3 activity, Bax expression, and decreased FSH, LH, E2 and Bcl-2 expression as compared to control group (p<0.05). Pterostilbene treatment significantly increased uterus and ovarian index, FSH, LH, E2 and Bcl-2 expression, and decreased PRL, caspase 3 activity and Bax expression as compared to control group (p<0.05). 40 mg/kg pterostilbene had similar efficacy as those of bromocriptine. Pterostilbene exerts its function in the treatment of HPRL via modulating apoptosis-anti-apoptosis homeostasis, inhibiting serum PRL level, and regulating secretion of gonadotropin hormones.