We have previously shown the anti-diabetic effects of swertiamarin; however, pharmacokinetic analysis showed that swertiamarin had a plasma half-life of 1.3 h. Gentianine is an active metabolite of swertiamarin that possesses a pharmacophoric moiety. The aim of this study was to explore the possibility whether the anti-diabetic effect of swertiamarin is due to gentianine. Swertiamarin treatment had no significant effect on adipogenesis, or the mRNA expression of PPAR-γ and GLUT-4; however, there was a significant increase in the mRNA expression of adiponectin. On the other hand, treatment with gentianine significantly increased adipogenesis, which was associated with a significant increase in the mRNA expression of PPAR-γ, GLUT-4 and adiponectin. These findings suggest, for the first time, that the anti-diabetic effect of swertiamarin is due to gentianine, an active metabolite of swertiamarin.

No abstract

We have investigated antihyperlipidaemic effect of swertiamarin (50 mg/kg, oral once) isolated from the perennial herb Enicostemma littorale Blume in poloxamer 407 (P-407)-induced hyperlipidaemic rats. Rats were made hyperlipidaemic by intraperitoneal administration of P-407 (400 mg/kg). Serum lipid levels such as total cholesterol, triglycerides and low-density lipoprotein cholesterol increased significantly (P < 0.001) compared with normal control rats. All these changes were significantly prevented in the rats treated with swertiamarin. Serum high-density lipoprotein (HDL) cholesterol was found to be reduced in the P-407 control rats. However, administration of swertiamarin significantly (P < 0.01) increased HDL levels and it showed a significant lipid-lowering effect, as well as a high antiatherogenic potential. Overall swertiamarin is an effective lipid-lowering lead compound and can be useful for preventing atherosclerosis.

Dyslipidaemia is one of the major risk factors for cardiovascular disease in diabetes mellitus. Lipid changes associated with diabetes mellitus are attributed to increases in free fatty acid flux, secondary to insulin resistance. In the present study, we have investigated the beneficial effects of swertiamarin on dyslipidaemic conditions associated with type 2 diabetes in streptozotocin-induced type 2 diabetic rats. Swertiamarin (50 mg/kg, i.p.) administered once a day for 6 weeks resulted in significant (p < 0.001) reductions in serum triglycerides, cholesterol and low-density lipoprotein levels in diabetic animals as compared with diabetic control animals. Serum fasting glucose was significantly (p < 0.05) decreased, moreover, the insulin sensitivity index was significantly (p < 0.05) increased in swertiamarin treated animals. Overall the data suggest that swertiamarin has beneficial effects on diabetic associated complications such as dyslipidaemia.