Screening Mildly Hypoglycaemic Compounds: Obese British Angora Rabbits with Borderline Glucose Intolerance as Animal Model

An obese animal model having mild glucose intolerance was developed by intravenous administration of sub-optimal dose of alloxan to British Angora rabbits. Mild hypoglycaemic activity of crude extract prepared from leaves of a Nepalese herb Biophytum sensitivum, which was missed by the conventional diabetic animal models, was demonstrable in these animals. Initial fasting hyperglycaemia observed immediately after treatment with alloxan in these animals was followed by reverting of the fasting blood glucose to normal or near normal levels. However, the blood glucose levels rose to higher than normal values following oral glucose load in the 1 h, 2 h and 3 h samples, reflecting glucose intolerance which was stable for up to 4 mo. Hypoglycaemic effect in these animals, designated obese glucose-intolerant (OGI) rabbits, was judged by improvement in glucose tolerance, tested by prevention of blood glucose elevation following oral glucose load. Comparing the corresponding pre-treatment and post-treatment values could even quantitate the hypoglycaemic effect.