The isoflavonoid calycosin inhibits inflammation and enhances beta cell function in gestational diabetes mellitus by suppressing RNF38 expression.

Gestational diabetes mellitus (GDM) is a medical complication and metabolic disorder associated with pregnancy. Calycosin is a traditional Chinese herbal medicine that is used for the treatment of multiple diseases. This study focused on exploring the effects and underlying mechanisms of Calycosin on GDM. The db/+ diabetic mice model of GDM was used to evaluate the effects of calycosin administration on the symptoms of GDM mice. Blood glucose, cytokine production (interleukin 6, IL-6; tumor necrosis factor-α, TNF-α), and insulin levels were measured by ELISA assay. The expression level of signal transducer and activator of transcription 3 (STAT3), ring finger protein 38 (RNF38), and SH2-containing protein tyrosine phosphatase 1 (SHP-1) were determined by Western Blot assay. Beta cell proliferation was assessed by CCK-8 assay. Our data indicated that administration of calycosin significantly improved the GDM symptoms in pregnant db/+ mice as demonstrated by reduced blood glucose, TNF-a, and IL-6 levels as well as increased insulin level, and body weight. Furthermore, we revealed that RNF38/SHP-1/STAT3 signaling should play a critical role in calycosin-promoted beta cell function, and forced expression of RNF38 attenuated the positive effects of calycosin on beta cells. Our study implied that calycosin exerts favorable effects on GDM mice via rebalancing insulin sensitivity and inflammatory response. [ABSTRACT FROM AUTHOR]