Hypotensive Effects and Phytochemical Profile of Aqueous Extract and Fractions of <i>Desmodium velutinun</i> Leaves (Willd) D. C. (Fabaceae) in the Rat

Abstract

Desmodium velutinum (D. velutinum) is a plant of the family Fabaceae used in traditional Congolese medicine for the treatment of high blood pressure (HBP) or hypertension (HT). The present work evaluated the hypotensive activity and determined the phytochemical profile of the aqueous extract and fractions of Desmodium velutinun (Willd) D. C. (Fabaceae) in the rat. The hypotensive effect of the aqueous extract and different fractions (F1, F2, F3 and F4) was evaluated at the dose of 2.5 mg/kg in normotensive rats anesthetized with 15% urethane at 1.5 g/kg, i.p. (intraperitoneally). Our results showed that the F3 fraction after administration caused a significant decrease in blood pressure and heart rate which remained higher than that of the aqueous extract and fractions (F1, F2 and F4). The richness in polyphenolic and flavonoid compounds as well as the separating capacity of the eluent used within the F3 fraction clearly justifies the beneficial effects of the latter on blood pressure and heart rate compared with the extract and fractions (F1, F2 and F4). In a second part we carried out the qualitative (thin-layer chromatography) and quantitative (total polyphenols and flavonoids determination) analysis. The chemical compounds remained dominated by the polyphenolic and flavonoid groups, the content of total polyphenols and total flavonoids meets the following increasing order: (extract, F1, F2, F3 and F4). The results obtained could certify the use of Desmodium velutinun in traditional Congolese medicine.