Antihyperglycemic and insulinomimetic activity of hydro alcoholic extracts of Anogeissus leiocarpus (Combretaceae)

Belonging to the family of Combretaceae, Anogeissus leiocarpus is a plant used by traditional practitioners to treat people living with diabetes mellitus in Togo (West Africa). The present study aimed to determine the hypoglycemic activity and the probable mechanism of action of the plant.

The hydroalcoholic extract and fractions of A. leiocarpus roots was evaluated on hyperglycemic mice by oral glucose tolerance test (OGTT) and on normoglycemic mice. The effect of the total extract and fractions was also measured in vitro on the adsorption and absorption of glucose ex vivo on intestine and skeletal muscles isolated from rats and in ovo on 11-day-old chicken embryos.

As the results, the total extract and fractions significantly (p< 0.0001) reduced hyperglycemia of mice compared to controls, 30 minutes after glucose overload. However, the more pronounced effect was observed with the supernatant fraction at 100 mg.kg^-1. On normoglycemic mice, the total extract at 500 mg.kg^-1 of the total extract did not lower (p>0.05) basal blood glucose levels compared to controls. In addition, the extract and fractions of A. leiocarpus in vitro adsorbed glucose, inhibited glucose intestinal absorption ex vivo and enhanced the glucose uptake by the muscle in the presence and absence of insulin compared to control group. In ovo, A. leiocarpus (0.03 and 0.06 mg / µL) induced a significant decrease (p <0.0001) in basal glycemia from the 30th min to 120 min.

In conclusion, the extract of A. leiocarpus has a strong antihyperglycemic activity similar to an insulin-mimetic effect.