Milicia excelsa (Moraceae) reversed the effects of letrozole-induced aromatase inhibition in rats with polycystic ovary syndrome

Abstract

Objectives: Polycystic ovary syndrome (PCOS) is an endocrinopathy affecting 5-20% of women of childbearing age. There is no single drug for the treatment of PCOS and current therapies have significant side effects. This study evaluated the ability of Milica excelsa to improve PCOS symptoms in rats.

Methods: Induction of PCOS was achieved using letrozole (a reversible aromatase inhibitor; 1 mg/kg; given orally for 21 days). From day 22, PCOS rats received the aqueous extract of M. excelsa roots (14 and 140 mg/kg). Clomiphene citrate (1 mg/kg) was administered to the positive control. The negative and the normal controls received the vehicle (5% DMSO). Treatments were given orally for 7 or 14 days. Vaginal smears were scrutinized daily during the experiment. Body weight was measured hebdomadal. Animals were sacrificed after the two treatment periods for biochemical and histological analyses.

Results: Aromatase inhibition caused hyperandrogenism (p<0.001), overweight (p<0.001) and fat accumulation (p<0.001). It also blocked the estrous cycle at the diestrus phase and altered ovarian dynamics as evidenced by the accumulation of cystic (p<0.001) and atretic (p<0.001) follicles. In contrast, M. excelsa induced weight loss (p<0.001), reduction in fat weight (p<0001), and lower serum androgen and LH levels (p<0.001). It also restored the estrous cycle and improved ovarian dynamics by increasing the amount of Graafian follicles (p<0.001) and corpora lutea (p<0.001), and decreasing that of cystic and atretic follicles (p<0.001).

Conclusions: Milica excelsa corrected hyperandrogenism and overweight in PCOS animals, and reduced cyst formation and follicle atresia in their ovaries.

Keywords: Milicia excelsa; aromatase inhibition; estrous cycle; letrozole; polycystic ovary syndrome.