Département de Génie Chimique et Procédés, Laboratoire d’Etude et de Recherche en Chimie, Université d’Abomey-Calavi, Ecole Polytechnique d’Abomey-Calavi, Cotonou, Benin
The present study aims to develop two medicinal plants used in Benin in the treatment of skin, urinary infections and septicemia. This study consists in determining the chemical composition, evaluating the antibacterial and antioxidant activities of the ethanolic, semi-ethanolic and aqueous extracts of the two plants investigated: Diospyros mespiliformis and Entada africana. The extracts of these plants were obtained by maceration for 72 hours. The identification of secondary metabolites carried out by the method of precipitation and staining in the tubes revealed the presence of tannins, saponosides, flavonoids, anthocyanins; alkaloids, coumarins, sterols and terpenes. The content of total phenolic compounds was estimated by the Folin-Ciocalteu method, it varies from 2455.36 ± 7.05 to 5141.51 ± 98.67 EAG / gMS for extracts of D. mespiliformis and 2261.00 ± 21.14 to 7256.6 ± 24.67 EAG / gMS for extracts of E. africana. The antioxidant activity of the extracts was evaluated by the anti-free radical test using the DPPH radical. The results obtained show that the extracts of E. africana have a higher free radical scavenging power than the extracts of D. mespiliformis. The antibacterial activity of the in vitro extracts against microorganisms is evaluated by two methods: diffusion on disc and microdilution. The results show that the ethanolic extract of D. mespiliformis exerts a bactericidal effect on S. aureus as well as the ethanolic and aqueous extracts of E. africana which have a bactericidal effect on the strains of S. aureus and SCN. These results show that the investigated extracts have antimicrobial properties and could be used in the fight against skin infections and septicemia. This justifies their use in traditional medicine.