Objective: To investigate the functional and metabolic alterations in cultured insulin resistant ovary model in vitro, and to observe the effect of berberine (Ber, a Chinese medical monomer) in improving insulin resistance (IR).
Methods: Ovary of mouse was cultured in vitro and treated by dexamethasone (Dex) to induce IR for establishing IR model ovary. The functional alteration in model ovary was assessed through detecting glucose and hormone levels in medium using RT-PCR, meanwhile, the expression of key molecules in insulin signal and steroid synthetic pathway were detected, and condition of IR improved by berberine was evaluated also.
Results: (1) The model ovary was made by Dex in dose- and acting time-dependent manner. After being treated by 300 nmol/L Dex for 48 h, the glucose uptake of ovary reduced from 9.05 +/- 0.75 mg/g to 2.48 +/- 0.29 mg/g (P < 0.05); it further decreased (from 9.59 +/- 1.74 mg/g to 1.94 +/- 0.19 mg/g, P < 0.01) under the stimulation of insulin, which proved that the IR model ovary was made successfully. Berberine significantly increased the glucose uptake of model ovaries (1.89 +/- 0.33 mg/g to 13.95 +/- 3.30 mg/g, P < 0.05). (2) As compared with control group, levels of testosterone (T) and androstenedione (A2) were higher, and levels of progesterone (P) and 17-hydroxyprogesterone (17-OHP) were lower significantly in the model. Berberine reversed the alternations of T, A2 and 17-OHP levels, but did not influence the level of P. (3) RT-PCR showed that the mRNA expressions of cytochrome 17-hydroxylase (CYP17) and mini-chromosome maintenance protein-2 (MCM-2) elevated, but extracellular regulated protein-1 (ERK-1), protein kinase B (AKT-2) and glycogen synthase kinase-3 (GSK-3beta) lowered in the medium after Dex inducing. Berberine treatment restored these molecular index obviously.
Conclusions: (1) Dex could induce IR in mouse ovary, which might enhance the androgenic synthesis. (2) Berberine could alleviate the degree of IR and the androgen synthesis, indicating that the Chinese sensitizing agents has favorable therapeutic effect for the treatment of polycystic ovaries.