Hypoglycemic, antihyperglycemic, and inhibitory effects of intestinal glucose absorption of a medicinal recipe of Parquetina nigrescens (Apocynaceae) and Erythrina senegalensis (Fabaceae) in the Wistar rat

Diabetes is a disease that is the fourth leading cause of hospitalization and death per year in the world. It is considered by WHO to be a public health problem. This study aims to evaluate the effects of a medicinal recipe, composed of Parquetina nigrescens (Apocynaceae) and Erythrina senegalensis (Fabaceae), on the glycemia of normoglycemic or carbohydrate overloaded rats and the intestinal absorption of glucose in Wistar rats. It appears that the aqueous extract of the drug recipe (RPNES) administered orally at doses of 600 and 800 mg/kg BW induces dose-dependent hypoglycemia in normoglycemic rats. The effects of this extract at 800 mg/kg BW on blood glucose are similar to that of glibenclamide (10 mg/kg BW), a standard sulfonylurea. Hyperglycemia caused by oral administration of glucose (4 g/kg BW) is significantly reduced in rats pretreated or post-treated with RPNES at 800 mg/kg BW. This extract is therefore a hypoglycemic and antihyperglycemic agent. Besides, RPNES (600 and 800 mg/kg BW) dose-dependently reduced the intestinal absorption of glucose in rats. The effects of RPNES at 800 mg/kg BW are similar to those of acarbose (0.2 mg/mL), a benchmark inhibitor of intestinal absorption. These results suggest that RPNES could contain molecules capable of inhibiting SGLT1 and GLUT2, just like the reference substance (acarbose).The hypoglycemic, antihyperglycemic and intestinal glucose absorption inhibiting effects of the aqueous extract of the medicinal recipe of Parquetina nigrescens and Erythrina senegalensis justify the use in the traditional medicine of this medicinal recipe against diabetes.