Plumbagin attenuates high glucose-induced trophoblast cell apoptosis and insulin resistance via activating AKT/mTOR pathway

Plumbagin, a bioactive phytoconstituent, is isolated from the root of Plumbago zeylanica L. Plumbagin pos-sesses antidiabetic effect to mediate glucose homeostasis, wound healing and diabetic nephropathy. However, the involvement of plumbagin in gestational diabetes mellitus (GDM) has not been reported yet. Trophoblast cell line (HTR8/SVneo) was incubated with high glucose to establish cell model of GDM. Cell viability and proliferation were detected by MTT and EdU staining. Flow cytometry was used to investigate cell apoptosis. Cell viability of HTR8/SVneo was reduced by high glucose or incubation of plumbagin. Plumbagin restored reduced cell viability and proliferation of HTR8/SVneo induced by high glucose. Plumbagin attenuated high glucose-induced cell apoptosis in HTR8/SVneo cells through upregulation of Bcl-2 and down-regulation of Bax, cleaved caspase-3 and cleaved caspase-9. Protein expression of glucose transporter type 4 (GLUT-4), insulin receptor (INSR)-B and INSR substrate (IRS1) was decreased in high glucose-induced HTR8/SVneo but increased by plumbagin. The suppressive effects of high glucose on phosphorylation of AKT and mTOR in HTR8/SVneo were reversed by plumbagin. Plumbagin improved high glucose-induced cell apoptosis and insulin resistance of HTR8/SVneo through activation of AKT/mTOR pathway, suggesting that plumbagin might be used as a potential strategy for the prevention of GDM.