Antihyperglycemic Activity of Swertia chirata on nSTZ-T2DM Rats: A Chronic Study

Aim: The present study aimed to investigate antidiabetic effects and to explore the underlying mechanism of S. chirata on neonatal-streptozotocin induced type 2 diabetic model (nSTZ-T2DM) rats.

Methodology: Stem-barks were collected from local market, identified from Bangladesh National Herbarium; 96% ethanol extract and overnight soaked water solution were prepared. T2DM was induced by a single ip injection of STZ to 48 hours Long Evans neonatal pups. After 3 months, T2DM adult rats (confirmed by OGTT) were divided into 4 groups: i) water control; ii) Glibenclamide (5 mg/kg bw); iii) soaked water (SCWS, 0.25 g/10 ml/kg bw) and iv) ethanol extract (SCE, 0.25 g/kg bw)treated groups respectively. Blood was collected by cutting tail tip on 0 and 21 day; by cardiac puncture on 28 day for measuring biochemical parameters. The data were analyzed using univariate & multivariate tools.

Results: SCE (p=0.003) and SCWS (p<0.001) treated group significantly improved OGTT of T2DM rats after three weeks administration. A significant decrease of fasting glucose level (p=0.01) and HOMA IR (p=0.01) were noticed in SCWS treated group after 28th day in comparison to initial day value respectively. Cholesterol was significantly decreased in SCWS on 28th day (p=0.02 and p=0.03) in comparison to water control and initial day respectively. Triglycerides was decreased in both treated groups and LDL level decreased by 42% in SCWS group respectively. Hepatic glycogen content of SCE was significantly increased (p=0.05) compared to water control. Serum ALT and creatinine level almost remained unchanged. A gradual fall of glucose absorption in SCE-krebs-glucose solution through GIT after 30 minutes was shown in Gut Perfusion Technique. Conclusion: S. chirata stem-bark possesses significant antihyperglycemic activity in T2DM rats which may be improved glucose tolerance, increased glycogenesis, decreased insulin resistance and total cholesterol level that may provide a rationale for using it in diabetic treatment.