Antidiabetic and antihyperlipidemic activity of ethyl acetate:isopropanol (1:1) fraction of Vernonia anthelmintica seeds in streptozotocin induced diabetic rats.

Ethanolic extract prepared from the seeds of Vernonia anthelmintica was evaluated for its antihyperglycemic activity in STZ (Streptozotocin) induced diabetic rats. Administration of ethanolic extract at a dosage of 0.50 g/kg bw produced the maximum fall (82%) in the blood glucose levels in diabetic rats after 6 h of treatment. Bioassay-directed fractionation using silica gel column chromatography was performed. Among the five fractions (A1, B1, C1, A2 and B2) obtained, of an initial chromatographic separation of the ethanolic extract, fraction A2 (100 mg/kg bw) showed the maximum antihyperglycemic activity which is significantly higher than that of the reference drug glibenclamide (20 mg/kg bw). Administration of the active fraction (100 mg/kg bw) for 45 days resulted in significant reduction in plasma glucose, HbA1(C), cholesterol, triglycerides, LDL, VLDL, free fatty acids, phospholipids and HMG-CoA reductase in STZ diabetic rats. In addition to that, significant decrease in plasma insulin, protein, HDL and hepatic glycogen observed in STZ diabetic rats, was normalized after 45 days of treatment with the active fraction of V. anthelmintica seeds. From the present study, it is evident that, the seeds of V. anthelmintica possess significant antidiabetic and antihyperlipidemic property without evident toxic effects.

Isolation and characterization of a novel antihyperglycemic protein from the fruits of Momordica cymbalaria.

AIM OF THE STUDY: A new antihyperglycemic protein was identified in the aqueous extract of fruits of Momordica cymbalaria by bioassay-guided fractionation. The study was aimed at isolation and characterization of this protein. MATERIALS AND METHODS: The active principle was purified to homogeneity by ammonium sulphate precipitation, gel filtration column chromatography on Sephadex G-50 followed by reverse phase HPLC. Its N-terminal amino acid sequence was identified and compared in the protein data bank. Optimum dose and route of administration of the active principle was determined in STZ induced diabetic rats. RESULTS: A 17kDa protein with an isoelectric point of 5.0 was identified as the active principle of antidiabetic action present in the aqueous extract of fruits of MC. It is named as M.Cy protein and found to be a novel protein by comparing its N-terminal amino acid sequence with those in the protein data bank. It did not produce any hypoglycemia in either normal or diabetic rats. CONCLUSIONS: The results suggest that 'M.Cy protein', present in the fruits of Momordica cymbalaria is an effective antihyperglycemic active principle in STZ induced diabetic rats at a dose of 2.5mg/kg b.w.