Phytochemical Screening and in-vitro Antibacterial Activity of 96% Ethanolic Extract of Khaya grandifoliola (Meliaceae) against Methicillin-Resistant Staphylococcus aureus (MRSA) Strains of Hospital Origin

Abstract

Objective: As part of efforts to promote medicinal plants found in the flora of Ivory Coast, this study focused on Khaya grandifoliola C. DC. (Meliaceae : Sapindales). The aim is to conduct a phytochemical study and evaluate the antibacterial activity of the bark of the Khaya grandifoliola trunk. Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes serious morbidity and mortality worldwide. Methodology: The extract from the bark of the Khaya grandifoliola C. DC. (Meliaceae : Sapindales)trunk was obtained by maceration for 24 hours in 96% absolute ethanol and subjected to phytochemical tests to detect the presence of polyphenols, flavonoids, coumarins, tannins, sterols, polyterpenes and saponins as secondary metabolites. Its antibacterial activity was evaluated on methicillin-resistant Staphylococcus aureus strains of hospital origin and a reference strain ATCC 29213. Results: The ethanolic extract of Khaya grandifoliola C. DC. (Meliaceae : Sapindales) exhibited antibacterial activity against all Staphylococcus strains, with bacterial growth inhibition diameters ranging from 15.7±0.6 to 22.3±0.6 mm at 200mg/mL; from 15.7±0.6 to 20.3±0.6 mm at 100mg/mL and from 13.7±0.6 to 18.7±0.6 mm at 50mg/mL. The ethanolic extract of Khaya grandifoliola C. DC. (Meliaceae : Sapindales) was active on the strains tested with minimum inhibitory concentrations (MIC) ranging from 12.5 to 3.12 mg/mL. It was bactericidal on all strains of Staphylococcus aureus. Conclusion: The results of the study revealed that the ethanolic extract of Khaya grandifoliola C. DC. (Meliaceae : Sapindales) was active at different concentrations on all strains tested, which justifies its traditional use in the treatment of certain bacterial diseases.