Biochemical evaluation of antihyperglycemic and antioxidative effects of Morinda citrifolia fruit extract studied in streptozotocin-induced diabetic rats

The hypoglycemic and antioxidative effects of Morinda citrifolia fruit extract were evaluated in streptozotocin (STZ)-induced diabetic rats. The ethanolic extract of Morinda citrifolia fruit at a concentration of 300 mg/kg body weight/rat/day was orally administered to STZ-induced diabetic rats for a period of 30 days. The elevated levels of blood glucose, glycosylated hemoglobin, blood urea, and serum creatinine in the diabetic rats reverted back to near normal after treatment with the noni fruit extract. Similarly significant decrease in the levels of plasma insulin and hemoglobin were elevated to near normal after treatment with fruit extract, suggesting the antihyperglycemic effect of Morinda citrifolia fruit. Determination of thiobarbituric acid reactive substance (TBARS), hydroperoxides, and both enzymatic and nonenzymatic antioxidants evidenced the antioxidative potential of the extract of noni fruit, which in turn may be responsible for its hypoglycemic potential. Alterations observed in the activities of pathophysiological enzymes such as serum aspartate transaminase (AST), serum alanine transaminase (ALT), and serum alkaline phosphatase (ALP) in the serum of control and experimental groups of rats revealed the tissue protective nature of Morinda citrifolia fruits, and the results of all the biochemical parameters analyzed were comparable with glyclazide, the standard reference drug.