Hypoglycemic Effect Of Vernonia Amygdalina On Type 2 Diabetic Mellitus And Regulation Of Hepatic Gluconeogenesis

Type 2 diabetes mellitus(T2DM)is one of the most serious health crisis in the past several decades.AMPK have emerged as an important pharmacological agent for improving insulin sensibility.Vernonia amygdalina(VA),a medicinal plant in the South African area,is used to treat many diseases in civil area.The present study investigates the efficacy of VA on insulin resistance regulation in streptozotocin(STZ)-induced diabetic mice and in palmitic acid(PA)-induced HepG2 cells.We also aimed to reveale the underlying mechanism involving in anti-diabetic actions of VA,in order to provide theoretical basis for T2DM clinical treatment.Our results showed that VA significantly reduced the levels of blood glucose,serum insulin and the homeostatic model assessment of insulin resistance(HOMA-IR)were significantly reduced to levels equivalent in non-diabetic mice.VA remarkably improved glucose tolerance at 6th week post-treatment.Moreover,VA triggered favorable changes in plasma lipids,that were identified by a significant decrease in TC,TG levels.In vitro,VA significantly down-regulated glucose production in PA-induced HepG2 cells.Furthermore,the expression of key gluconeogenic enzyme phosphoenolpyruvate carboxykinase(PEPCK)and glucose-6-phosphatase(G6Pase)were down-regulated significantly in PA-induced HepG2 cells and STZ-induced liver tissue following VA treatment.However,these beneficial changes in glucose production,gluconeogensis and the expression of PEPCK and G6Pase induced by VA were almost completely reversed by the AMPK inhibitor Compound C.Our data demostrated that VA exerted advantageous effects on glucose and lipid metabolism.These roles may be due to its beneficial effects on AMPK mediated inhibition of gluconeogensis.Therefore,our results suggested that VA may be a potential and effective medicinal herb against type 2 diabetes.