Phytochemical Profiling and Anti-MRSA Activity of Extracts from Moringa oleifera Lam. and Senna occidentalis (L.) Link Cultivated under Organic Conditions

Abstract

The emergence of antibiotic-resistant bacterial strains, particularly Methicillin-Resistant Staphylococcus aureus (MRSA), is a major threat to global public health. In this context, medicinal plants represent a promising alternative for the discovery of new antimicrobial agents. The aim of this study was to explore the phytochemical profile and assess the antibacterial activity of extracts in solvents of different polarity from Moringa oleifera (leaves, stem bark, flowers) and Senna occidentalis (leaves, stem bark, seeds, pods) against clinical strains, including 10 MRSA strains, 4 methicillin-sensitive Staphylococcus aureus (MSSA) strains, and an ATCC 25923 strain for quality control. The extracts were obtained by maceration in water, ethanol (70 %) and dichloromethane, followed by concentration in a rotary evaporator. Phytochemical screening was carried out using conventional chemical reactions in a tube, enabling the presence of secondary metabolites such as flavonoids, tannins, alkaloids, saponins, sterols, triterpenes, anthocyanosides, coumarins and reducing compounds to be identified. Assessment of the antimicrobial activity, using disk diffusion and broth dilution methods, revealed that M. oleifera flower extract exhibited marked antibacterial activity, with an inhibition zone of more than 10 mm and a bactericidal effect with a MBC/MIC ratio ≤ 4. In comparison, S. occidentalis showed more modest activity. These results suggest that M. oleifera extracts could be an effective natural alternative in the treatment of infections caused by resistant strains of staphylococci.