Phytochemical Analysis and Bioactivities Studies of Fresh Leaves and Flowers from C. roseus, L. multiflora and P. amarus, Beninese Medicinal Plants Used Against Diabetes

Abstract

Traditional herbal medicines make up a large part of drug use. This work addressed an area of public health, the fight against diabetes. The present study aimed to carry out qualitative and quantitative screening of the secondary metabolites of extracts from the leaves and flowers of plants such as Catharanthus roseus, Lippia multiflora and Phyllanthus amarus, and to evaluate the antioxidant activity in their aqueous and ethanolic extracts, their larval toxicity and then to predict the antidiabetic activity. The results showed that its plants have in their various extracts some secondary metabolites such as alkaloids, tannins, flavonoids, coumarins, terpenoids, phenolic compounds, steroids, etc responsible for several interesting pharmaceutical activities. These medicinal plants showed a higher quantity of polyphenols in the hydro-ethanolic extracts, with levels of 60.65±0.13; 44.40±1.43 and 67.11±0.39 mg.eq/g respectively for C. roseus, L. multiflora and P. amarus and also a higher antioxidant potential for L. multiflora and P. amarus than the standard Vitamin C, with IC50 equal to 0.53 and 0.52 mg/mL respectively. Extracts are not toxic against larvae. These results are an important indicator of the hypoglycemic and anti-diabetic activity and confirmed the potential for use of these plants by the population in the fight against diabetes.