Antidiabetic, antioxidant, and TNF-α lowering properties of extract of the traditionally used plant Ixeris gracilis in alloxan-induced diabetic mice

Context: Ixeris gracilis DC. Stebbins (Asteraceae) is a plant considered to be medicinal by local communities of Meghalaya, India. Objective: To evaluate the antidiabetic potential, antioxidant activity, and effect of the 80% methanolic extract of the leaves of Ixeris gracilis on tumor necrosis factor-alpha (TNF-alpha) expression. Materials and methods: Varying doses (250-1000 mg/kg body weight) were administered intraperitoneally to normoglycemic mice and their hypoglycemic properties noted for 24 h; the optimum dose observed was used to evaluate its antihyperglycemic activity and effect on glucose tolerance. In vitro antioxidant activity was analyzed by assessing the DPPH radicals scavenging ability of the extract and the total polyphenols, flavonoid, carbohydrate, and protein contents were determined. Diabetic mice were then subjected to daily intraperitoneal injections of the extract for 12 days after which the antioxidant enzyme activities in the tissues were assayed and serum TNF-alpha was evaluated by ELISA. Results: The extract displayed varying hypoglycemic activity. The dose of 250 mg/kg body weight exhibited potent antihyperglycemic activity and improved glucose tolerance. The extract was able to scavenge free radicals (IC50 57.544 mu g/ml) and contained polyphenol (76.269 +/- 0.204mg GAE/g dry wt), flavonoid (70.070 +/- 0.626mg rutin equivalent/g dry wt), protein (4.368 +/- 8.916 mg/g dry wt), and carbohydrate (558.189 +/- 0.002 mg/g dry wt). TNF-alpha level and overall activity of glutathione peroxidase and superoxide dismutase in the liver, kidney, and brain of extract-treated diabetic mice were improved. Conclusion: The study supports the inclusion of Ixeris gracilis in the list of plants with antidiabetic potential.