A Study of the Effect of Phyllanthus Amarus Extracts on Blood Glucose in Rabbits

Abstract

Aerial parts of Phyllanthus amarus are used by Traditional Healers of Tanga, northeastern Tanzania, to control symptoms of non-insulin dependent diabetes mellitus (NIDDM). An aqueous extract of the aerial parts, 0.1 and 1 g/kg body weight, significantly enhanced clearance of glucose from the blood as compared to controls during an oral glucose tolerance test (OGTT), using normal fasted albino rabbits (P = 0.05). The two doses of the extract reduced the area under the OGTT curve by 7.8% and 11.4%, respectively. Both doses had no effect on blood glucose in the unfed rabbits. Chlorpropamide, 0.1 g/kg body weight, showed a greater effect, than both doses, on glucose clearance in the fed state and on blood glucose in the fasted rabbits (P = 0.05). A methanol extract of the aerial parts, 1 g/kg body weight, worsened glucose tolerance causing a significant increase in area under the OGTT and fasting blood glucose curves (P = 0.05). We conclude that the aqueous extract contains a hypoglycaemic activity as claimed by traditional healers. This activity is absent in the methanol extract, thus emphasizing the importance of preparing extracts in the same way as the healers. Further work is required to isolate the active substance before proper comparison with a standard drug can be done.