Elucidation of Phytochemicals and Antidiabetic Activity of Methanolic Ex-tract of Piper betle Leaves on nSTZ-Induced Type 2 Diabetic Model Rats

Piper betle is an evergreen plant that has been claimed to possess various therapeutic properties including diabetes for a long period of time. The present study was undertaken to evaluate the antidiabetic effects of Piper betle (100% methanolic extract) on neonatal streptozotocin (nSTZ) induced type 2 diabetic (T2DM) model rats. P. betle methanolic extract preparation and phytochemicals screening test were done by following standard methods. Diabetes was induced in 48hrs rat pups by a single ip injection of STZ (90mg/kg bw). After three months, OGTT was done (glucose 2.5g/10ml/kg bw) to find out their glycemic status. Six normal and 18 T2DM Long Evans rats were chosen and divided them into four groups. Where group (i) was comprised of normal rats i) Normal water control (NWC); ii) Diabetic water Control (DWC), iii) Gliclazide (GT 20mg/5ml/kg bw) and iv) P. betle (1.25g/10ml/kg bw) extract treated groups respectively. In 28 days, experimental period groups (i) and (ii) received water orally (10ml/kg bw) respectively with a single feeding. 24 Blood samples were collected at the beginning by tail cut and cardiac puncture method was done at the end of the study under halothane anesthesia. Blood serum and dissected small portion of the liver were stored at -20˚C refrigerator for biochemical (fasting serum glucose, serum insulin, serum lipid profiles) and liver glyco-gen estimation. Statistical Analysis was done by using SPSS-16 software. Phytochemicals screening revealed that P. betle extract contain significant amount of tannins, flavonoids, phenols, and terpenoids. Oral consumption of P. betle showed that, a significant (P<0.01) reduction of FSG had been found when compared to the base line value. Moreover, while compared to the DWC a significant (P< 0.01) reduction of FSG has been found in P. betle treated group respectively. GT group also ameliorated FSG significantly (p<0.03) while compared to the base line value. Liver glycogen content was increased (24%) in P. betle treated rats when compared to the DWC group. Serum insulin level also increased significantly (P< 0.001) when compared to the baseline value. Furthermore, the consecutive treatment of P. betle resulted in a significant reduction of TG and Cholesterol (p<0.001 & p<0.02), a 10% decrease in LDL, and a significant increase in HDL (p<0.01). The findings of our study suggest that P. betle possesses significantly hypoglycemic and insulinomimetic properties due to the abundant sources of phytochemicals.