Study of the toxicity and phytochemical activity of the aqueous extract of the recipe based on leaves of Brillantaisia patula T. Anderson (Acanthaceae) and Desmodium velutinum Willd (Fabaceae)

The Republic of Congo has an abundant flora rich in plant species. This study was conducted to evaluate the toxicity and phytochemical activity of the aqueous extract of the recipe (AER) based on Brillantaisia patula and Desmodium velutinum leaves. For the acute toxicity study, mice were fasted for 4 hours, then divided into groups of 3 mice and treated by gavage with the aqueous extract of the recipe (AER) at a dose of 5000 mg/kg. The behavior of the animals and mortality were observed for 48 hours after administration of the products. In the subacute toxicity study, rats were force-fed daily for 28 days with the aqueous extract of the recipe at a dose of 500 mg/kg/day. Before and throughout the study, weight gain and food consumption were recorded. We also analyzed the hematological and biochemical parameters of the rats at the end of the study.  The phytochemical activity of the aqueous extract of the recipe was determined by tube reactions and thin-layer chromatography. The results show that the aqueous extract of the recipe is slightly toxic, with an LD₅₀ greater than 5000 mg/kg. Hematological and biochemical analyses show a significant increase (p < 0.05) in blood platelet counts and mean corpuscular volume on the one hand, and an increase in ALT and AST levels on the other. Phytochemical activity revealed the presence of alkaloids, tannins, reducing sugars, oses and holosides, flavonoid derivatives, and saponosides. In conclusion, the aqueous extract of the recipe is slightly toxic and very rich in secondary metabolites.