Hypoglycaemic Activity of Centella asiatica (L) Urb

Abstract

The water extract of whole plant of Centella asiatica is used by traditional healers in the Haya tribe in Bukoba Region in Tanzania, in the management of both insulin and non-insulin dependent diabetes mellitus. Centella asiatica administered orally at a dose of 2 g/kg and 4 g/kg body weight produced a significant hypoglycaemic activity (P <0.05) in glucose primed fasted rabbits, with an average % mean deviation of 25.6 and 34.9 respectively, at a dose dependency ratio of 2:3. Fractions containing quaternary amine and triterpene given at a dose of 400 mg/kg body weight in fasted glucose primed rabbits produced a significant hypoglycaemic effect with a mean deviation of 74 % (quaternary amine) and 84% (triterpene) respectively, compared to tolbutamide that produced 62 % mean deviation. Unlike tolbutamide, Centella asiatica did not reduce blood sugar below normal levels. The aqueous extract of C. asiatica also significantly enhanced the uptake of glucose into isolated rat hemidiaphragm, incubated at 37 0 C for 3 h in Glucose Kreb Ringers buffer (GKBR) solution. Glucose uptake induced by C. asiatica extracts was comparable with the absorption caused by insulin. Glucose uptake was most significant in leaves, followed by roots, whole plant and stems. The experiment confirms the rationale of the use of Centella asiatica in both type 1 and type 11 diabetes mellitus.