Astragalin reduces ovarian failure in an aged rat model of menopause by inhibiting granulosa cell apoptosis

A traditional Chinese medical (TCM) formula, containing five medicinal herbs including Morus alba L. (mulberry; Moraceae), has been shown to be effective in clinical trials for the management of menopausal symptoms. Mulberry has been used in TCM for thousands of years for the treatment of a wide range of women's reproductive disorders including breast cancer, dysmenorrhea, and menopause. Astragalin (AST), known chemically as kaemperferol-3-O-glucoside is a flavonoid glycoside isolated from mulberry fruits. The in vitro and in vivo activities of AST on ovarian granulosa cell (GC) apoptosis were investigated. The effects of AST on cadmium chloride-induced apoptosis in cultured rat ovary GCs were investigated using the MTT proliferation assay, the proliferation-related index and the Annexin V apoptosis assay. The in vivo effects of AST on 14-month old female rats were examined by measuring serum estrogen and progesterone levels, as well as the apoptosis rate of ovarian GCs by flow cytometry.

The in vitro results showed that AST stimulated GC proliferation, increased 17β-estradiol (E2) and progesterone (P4) secretion, and reduced cadmium chloride-induced apoptosis. In vivo, AST treatment of aged female rats resulted in significant increases of serum E2 and P4 levels, altered levels of serum FSH and LH levels, and reduced apoptosis in ovarian GC cells. Treatment with AST increased anti-apopotic protein Bax and reduced the pro-apoptotic protein Bcl-2 in cultured rat ovarian GCs.