Hypoglycaemic Activity of Dioscoretine from Tubers ofDioscorea dumetorumin Normal and Alloxan Diabetic Rabbits

• DOI: 10.1055/s-2006-960952
• Publication Date: 2007-01-15T10:10:47Z
• Authors: M. Iwu; C. Okunji; G. Ohiaeri; P. Akah; D. Corley; M. Tempesta
• Keywords: 0301 basic medicine; 03 medical and health sciences; Alkaloids; Plants, Medicinal; Alloxan; Animals; Hypoglycemic Agents; Rabbits; Bridged Bicyclo Compounds, Heterocyclic; Diabetes Mellitus, Experimental; 3. Good health

Dioscoretine isolated from the aqueous fraction of the methanol extract of Dioscorea dumetorum tubers when administered intra-peritoneally to normal and alloxan diabetic rabbits produces significant hypoglycaemic effects at a dose of 20 mg/kg. The fasting blood sugar in normoglycaemic rabbits was reduced from 112 mg/100 ml to 55 mg/100 ml after 4 hours. In alloxan diabetic rabbits, the blood sugar was lowered from 520 mg/100 ml to 286 mg/100 ml at the same time interval. The aqueous fraction of the methanol extract produced comparable effects at 100 mg/kg. The chloroform fraction of the same extract raised the fasting blood sugar of normal rabbits to 196 mg/100 ml after 6 h. The acute toxicity studies gave LD50 values of 1.4 g/kg for the aqueous fraction and 0.58 g/kg for dioscoretine when tested on mice. The hypoglycaemic effects were compared to those of tolbutamide.