Phytochemical and In vivo Pharmacological Evaluation of Ethyl Acetate Extract of Marrubium vulgare L (Leaves) for Anti-diabetic Activity

The present study aimed to investigate phytochemical contents and anti-diabetic activity of Marrubium vulgare L. leaves ethyl acetate extract. The qualitative chemical analysis revealed the presence of glycosides, alkaloids, flavonoids, phenols, saponins and steroids as the major constituents. In vitro α-amylase and α-glucosidase enzyme inhibitory activities (IC50 values) were 487.3 µg/mL and 392.95 µg/mL respectively, compared to acarbose (277.43 and 269.23 µg/mL respectively) for the dose dependent inhibition. No effects were observed on acute toxicity studies (OECD 423, 2000 mg/kg) which means that there is a large safety margin. The extract was administered orally for 28 days at 200 and 300 mg/kg respectively to streptozotocin induced diabetic rats and resulted in significant decrease in fasting blood glucose by 52% and 63% respectively as compared to 70% for metformin at 100 mg/kg. Therapeutic intervention showed improvement in body weight and decrease in the raised serum urea (46–52 %), uric acid (41–48 %) and creatinine (67–75 %) in comparison to diabetic control. In the experiments with everted jejunal sac, the extract (5 mg/mL) was able to inhibit the glucose absorption by 36.37%. Histological assessment of pancreatic tissue revealed a dose-dependent recovery of islet architecture with near normal architecture at 300 mg/kg. The results indicated that the extract of the ethyl acetate fraction of Marrubium vulgare L. has anti-diabetic property with no toxic effect and conformed with the traditional uses of Marrubium vulgare L. and further extraction of active constituents is desired.