Phytochemical screening and evaluation of antiradical and antibacterial activities of stem and root barks of Gardenia ternifolia Schumach. (Rubiaceae): A plant traditionally used in northern Côte d'Ivoire

Gardenia ternifolia is an Ivorian plant species used to treat tooth decay, hemorrhoidal crises, leprosy, skin diseases and rheumatism. The present study is based on phytochemical screening and evaluation of the antiradical and antibacterial activities of aqueous, hydroethanolic and ethanolic extracts of G. ternifolia stem and root barks. Phytochemical screening of secondary metabolites was carried out using tube color reaction methods and Thin Layer Chromatography (TLC). Phytochemical screening revealed the presence of polyphenols (flavonoids, coumarins, tannins), saponins, steroids and terpenoids in G. ternifolia stem and root extracts. Phenolic acids were revealed only in stems, while alkaloids were absent in both organs studied. Anti-radical activities were highlighted in both organs by qualitative and quantitative methods with respect to the DPPH free radical. However, quantitative spectrophotometric analysis showed better antioxidant activity in stems than in roots. Antibacterial activity assessed against 05 bacterial strains using the solid-medium diffusion and liquid-medium dilution methods showed that only the aqueous and ethanolic extracts of G. ternifolia stems were absolutely bactericidal against the Staphylococcus aureus strains tested (S.a ATCC 29213, S.a 06 UB/22 and S.a 27 UB/22). The results obtained could give the stems the ability to treat infections caused by S. aureus bacteria.