Antioxidant Potential, Hypoglycemic Effect and Safety of Ajuga chamaecistus Ging. ssp. tomentella (Boiss.) Rech. f. Aerial Parts

Background and objective: Ajuga species(Lamiaceae) are traditionally used in the treatment of jaundice, joint pain, sciatic nerve, and diabetes in different countries. The aim of this study was to investigate the antioxidant and hypoglycemic activities and safety of Ajuga chamaecistus ssp. tomentella. Methods: Antioxidant activity, radical scavenging effect, and total phenolics content of the aqueous and methanol extracts were assessed using ferric reducing antioxidant power (FRAP), 2, 2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging and Folin-Ciocalteu methods. Streptozotocin (STZ) induced diabetic mice were studied in separate groups comprising aqueous and methanol extracts (200, 400, 800 mg/kg), metformin (500 mg/kg) and a negative control group. Results: The n-butanol fraction showed the most phenolics content (26.5 mg GAE/g of extract) and the highest antioxidant power) 346.7 mmol FeІІ/g of extract) as well as the most considerable radical scavenging activity (IC50=15.34 µg/mL). In STZ-diabetic mice, repeated oral administration of all doses of extracts showed a significant decrease in plasma glucose levels after 3, 14 and 28 days. The results of acute toxicity study showed that the ethanol extract was non-toxic up to the dose of 6000 mg/kg. Based on the sub-chronic toxicity results, a significant decrease in cholesterol and triglyceride was observed after using the extract (1000 mg/kg) for 23rd and 45th days. Histopathology of animal tissues revealed no significant differences in animal tissues between treated and control groups after 23 and 45 days. Conclusion: our study indicated the antioxidant potential, safety and hypoglycemic effect of A. chamaecistus ssp. tomentella extracts.