RETRACTED: Anti-diabetic activity of Swertia corymbosa (Griseb.) Wight ex C.B. Clarke aerial parts extract in streptozotocin induced diabetic rats.

Swertia corymbosa locally called as Shirattakuchi have a long history of use in Ayurveda herbal preparations in Indian traditional system of medicine. It has been used in folklore medicine for the treatment of diabetes.

The present study aimed to investigate the effect of the methanolic extract of Swertia corymbosa (SC) in diabetic and to analyze its chemical composition by HPLC-ESI/MS that may correlate with their pharmacological activities.

The in vitro anti-diabetic activity of the extracts was measured by using α-glucosidase and α-amylase enzyme inhibitory activity. The methanolic extract of Swertia corymbosa were administered orally (125, 250 and 500 mg/kg, for 28 days) to streptozotocin-induced diabetic rats. Hypoglycemic effects, oral glucose tolerance test, change in body weight and lipid profile, biochemical analysis and histopathological examination were assessed. High-performance liquid chromatography-electrospray ionization/mass spectrometry (HPLC-ESI/MS) method was also developed to analyze the chemical composition.

In vitro anti-dabetic study, the methanol extract of SC is found to be a potent inhibitor of α-glucosidase and α-amylase activity. Oral administration of SC and standard drug for 28 days caused a significant decrease in the concentrations of blood glucose level, total cholesterol (TC), serum triglycerides (TGs), low-density lipoprotein-cholesterol (LDL-C), malondialdehyde (MDA) and significant increase in the concentrations of high density lipoprotein-cholesterol (HDL-C), serum insulin and body weight. Furthermore, activities of antioxidative enzymes, including SOD, GPx, GSH and CAT were enhanced dosed dependently with SC. Histopathological studies of the pancreas showed the regeneration of the β-cells by extract which were earlier necrosed by streptozotocin. Ten major compounds such as loganic acid (1), swertiamarin (2), sweroside (3), gentiopicroside (4), isovitexin (5), amoroswertin (6), amarogentin (7), gentiacaulein (8), decussatin (9) and swertianin (10) were analyzed by HPLC-ESI/MS system.

These results demonstrate that SC aerial parts of methanolic extract is an effective anti-diabetic and antioxidant activities which provides the scientific proof for the folklore medicine.