Cryptotanshinone reverses ovarian insulin resistance in mice through activation of insulin signaling and the regulation of glucose transporters and hormone synthesizing enzymes

Objective: To investigate the effects of cryptotanshinone (CRY), an active component of Chinese medicine, on ovarian androgen production, Insulin resistance (IR), and glucose metabolism in mice.

Design: Animal model and in vitro tissue model.

Setting: University-affiliated laboratory.

Animal(s): Mice.

Intervention(s): Ovarian IR was induced by dexamethasone (DEX) in vivo. Animals were randomized to receive CRY treatment for 3 days or not. Ovulation rates, serum steroid levels, and glucose uptake in ovaries were quantified, and proteins in the phosphatidylinositol 3-hydroxy kinase pathway were measured. In vitro ovarian IR was also induced by DEX for 3 days. Ovarian steroid hormone secretion and glucose uptake were measured, and the hormone-synthesizing enzymes were determined by semiquantitative reverse transcription-polymerase chain reaction.

Main outcome measure(s): Ovarian glucose uptake, in vivo ovulation rate, serum and culture medium steroid level, and molecular expression of phosphatidylinositol 3-hydroxy kinase and steroidogenic enzymes.

Result(s): Dexamethasone significantly increased ovulation rates in vivo and increased T and E2 production and decreased ovarian glucose uptake in vivo and in vitro. Cryptotanshinone significantly reduced ovulation rates in vivo and decreased T and estrogen production in vitro. Cryptotanshinone attenuated the inhibition of DEX on Akt2 and suppressed the up-regulation of CYP11 and CYP17 expression by DEX.

Conclusion(s): Cryptotanshinone reversed DEX-induced androgen excess and ovarian IR in mice through activation of Insulin signaling and the regulation of glucose transporters and hormone-synthesizing enzymes. This suggests a potential role for CRY in treating the ovulatory dysfunction associated with PCOS.