Conysa aegyptiaca (L.) Dryand ex. Aiton extract exhibite antioxydant activity and prevent hepatic glucose liberation in vitro

Abstract

Also called ahlonmè in Ewe, Conyza aegyptiaca (L.) Aiton (C. aegyptiaca) is one of the plants used for diabetes treatment in West Africa. In type 2 diabetes patients, enhanced glucose output by liver contributes to hyperglycemia and inhibition of hepatic glucose production favors glycemic control. In this study, we analyzed the effect of C. aegyptiaca on hepatic glucose release. Freshly collected liver from rats sacrificed under anesthesia was cut into small pieces. The pieces were thoroughly rinsed and incubated under stirring with appropriate dilutions of the extracts of C. aegyptiaca. Glucose level was determined in the incubation medium over time by Glucose Oxidase method. Aqueous and ethanolic extracts of C. aegyptiaca showed no larvae toxicity. The liver glucose liberation test showed that glucose levels decreased significantly (p <0.005) at all tested concentrations of extracts compared to control. Glucose level increased over time in the control medium without extract. When liver pieces were incubated with extract, glucose was kept at significantly (p <0.005) lower level compared to control. The maximum rate of inhibition of hepatic glucose release was achieved 20 minutes (p <0.001) and 30 min (p <0.005) after incubation respectively for the ethanolic and aqueous extracts. Glucose level measured in the incubation medium with the ethanolic extract is significantly (p <0.05) lower than that of the aqueous extract. Our results show that C. aegyptiaca extracts prevent hepatic glucose liberation and suggest that this property contributes to the antdiabetic effect of the plant.