Comparative Evaluation of Hypoglycaemic Activity of Two Medicinal Plants in Alloxan Diabetic Rats

Aqueous extracts of the seeds of fenugreek (Trigonella foenum graecum) and fruits of bitter gourd (Momordica charantia) were tested for their hypoglycemic activity. The aqueous extracts or just the solvent alone (control) were orally administered daily for 7 days (short term) or 15 days (long term) to alloxan-induced diabetic rats. Blood glucose and plasma insulin levels and the subsequent effect on Oral Glucose Tolerance Test (OGTT) were monitored at 3, 6 and 9 h after the last administration. Daily administration of T. foenum graecum for 7 days failed to induce any significant change in the blood glucose levels. However, an extended 15-day treatment regimen was found to significantly reduce the blood glucose levels. The blood glucose levels were found to decrease at 6 and 9 h after the final administration of the extract. In contrast, both 7 and 15 days daily administration of M. charantia reduced the blood glucose levels drastically (p<0.05 and p<0.01, respectively). Significant reduction in blood glucose levels was observed at 6 and 9 h after the short-term treatment and at 3, 6 and 9 h after the long-term treatment. Long term administration of both T. foenum graecum and M. charantia was found to decrease blood glucose levels during OGTT at 30, 60 and 90 min when compared to OGTT of diabetic animals. There was no change in plasma insulin levels subsequent to administration of either T. foenum graecum or M. charantia. The observed results indicate that T. foenum graecum and M. charantia have hypoglycemic effect. The fact that the plasma insulin levels were unaltered suggests that the probable mechanism does not involve β-cell and may be attributable to decrease in intestinal absorption of glucose.