Preliminary Study to Assess the Antioxidant and Antibacterial Activity of Extracts from the Leaves of Morelia Senegalensis (A Rich)

Abstract

frican populations rely heavily on traditional medicine, which uses plants to treat human and animal diseases. However, scientific validation of this empirical knowledge concerning the efficacy, toxicity and dosage of the proposed treatments is urgently needed. The aim of this study was to evaluate the antioxidant and antibacterial activity of Morelia senegalensis leaf extracts on the 2,2-diphenyl-1-picrylhydrawyl (DPPH) radical and the (2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) ABTS cation radical and on four reference bacterial strains (E. coli 25922, E. coli 35218, E. faecalis 29212 and S. aureus 29213) using protocols already described in the literature. The phytochemical screening test revealed the presence of flavonoids, alkaloids, tannins, saponins, reducing compounds and sterols in Morelia senegalensis leaves. All the extracts showed antioxidant activity to varying degrees. The most active ethyl acetate (AE) extract had half-maximum inhibition concentration (IC50 )of 0.33 and 0.62 mg/mL for the ABTS and DPPH tests respectively, followed by DCM and EB extracts with IC50 of 0.86 and 0.88 mg/mL for the ABTS test respectively, while the vitamin C used as a reference was more active with IC50 of 0.04 and 0.06 mg/mL. Antibacterial activity showed inhibition diameters ranging from 7 to 16 mm depending on the concentration and strain considered. The ethyl acetate fraction was the most active on S aureus 29213 with an inhibition diameter of 16 mm at 50 mg/mL. These interesting results were confirmed by the Minimal Inhibitory Concentration inhibitory (MIC) and Minimal Bacterial Concentration (MBC) studies, which showed that all the extracts had a bactericidal effect on all the studied strains. Morelia senegalensis plant has shown promising preliminary results in the treatment of bacterial infections. Further studies are needed to isolate and characterize the secondary metabolites contained in the leaves of this plant.