Evaluation of Antidiabetic Effects of the Traditional Medicinal Plant Gynostemma pentaphyllum and the Possible Mechanisms of Insulin Release

Autor: Wan Mohamud Wn, Harvest F. Gu, Lokman Ef, Claes-Göran Östenson
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Evidence-based Complementary and Alternative Medicine : eCAM
Evidence-Based Complementary and Alternative Medicine, Vol 2015 (2015)
ISSN: 1741-4288
1741-427X
Popis: Aims. To evaluate the antidiabetic effects ofGynostemma pentaphyllum(GP) in Goto-Kakizaki (GK) rat, an animal model of type 2 diabetes, and to investigate the mechanisms of insulin release.Methods. Oral glucose tolerance test was performed and plasma insulin levels were measured.Results. An oral treatment withGP(0.3 g/kg of body weight daily) for two weeks in GK rats improved glucose tolerance versus placebo group (P<0.01). Plasma insulin levels were significantly increased in theGP-treated group. The insulin release fromGP-treated GK rats was 1.9-fold higher as compared to the control group (P<0.001).GPstimulated insulin release in isolated GK rat islets at high glucose. Opening of ATP-sensitive potassium (K-ATP) channels by diazoxide and inhibition of calcium channels by nifedipine significantly decreased insulin response toGP. Furthermore, the protein kinase A (PKA) inhibitor H89 decreased the insulin response toGP(P<0.05). In addition,GP-induced insulin secretion was decreased after preincubation of GK islets with pertussis toxin to inhibit exocytoticGeproteins (P<0.05).Conclusion.The antidiabetic effect ofGPis associated with the stimulation of insulin release from the islets.GP-induced insulin release is partly mediated via K-ATP and L-type Ca2+channels, the PKA system and also dependent on pertussis toxin sensitiveGe-protein.
Databáze: OpenAIRE
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