Antidiabetic potential of aqueous extract of Citrus limonia leaves on experimental animal models

Several plants have been scientifically evaluated to be beneficial for diabetes mellitus management world over. Plants are important for pharmacological research and drug development, not only when bioactive phytocompounds are used directly as therapeutic agents, but also as starting materials for the synthesis of drugs or as models for pharmacologically active compounds. The present study is therefore an expansion towards developing a novel oral antidiabetic medicine of superior quality with negligible or no side effects. This study therefore, examined the glycemic power of Citrus limonia L. (Rutaceae) leaves aqueous extract in normal as well as diabetic models and the possible role of its phytocompounds in generating this bioactivity. The variable doses of 100, 200, 300, and 400 mg kg-1 body weight (bw) of the extract were administered orally to normal and streptozotocin (STZ) induced sub and mild diabetic rats. The dose of 300 mg kg-1 bw was ascertained as the most effective dose capable of reducing the blood glucose level (BGL) by 35.4% (p<0.001) at 6 h and 19.5% (p<0.001) at 3 h during fasting blood glucose (FBG) and glucose tolerance test (GTT) studies in normal rats, respectively. Whereas, the maximum fall observed in case of sub and mild diabetic rats during GTT studies was 24.4, and 33.8% (p<0.001), respectively, at the same interval of time. Moreover, chemical tests were carried out on the leaf extract using standard procedures to identify the main classes of phytoconstituents present viz. terpenoids, flavonoids, alkaloids, tannins, carbohydrates and glycosides, saponins as well as steroids. This verification clearly proves that the aqueous extract of Citrus limonia leaves holds potent hypoglycemic effect as well as strong antidiabetic potential which may be due to the presence of certain class of compounds in the extract as evident from preliminary phytochemical screening.