In-vitro Synergistic Antimicrobial Activity of Melia azedarach and Solanum incanum Ethanolic Leaf Extracts Against the Staphylococcus aureus

Abstract

The increasing challenges of adverse drug reactions, costly medicines, and antimicrobial resistance necessitate the exploration of safe and effective antimicrobial agents. This study aimed to evaluate the antimicrobial activity of ethanol leaf extracts from Melia azedarach and Solanum incanum against Staphylococcus aureus, a clinically significant pathogen known for its resistance to conventional antibiotics. The research design employed was an experimental study with three concentrations of the plant extracts (1g/ml, 1.4g/ml, and 2g/ml) tested against Staphylococcus aureus, and the standard antimicrobial agent, ciprofloxacin, served as a positive control, while ethanol served as a solvent control. The samples were prepared, and the experiments were conducted in triplicate, following established protocols. The choice of Melia azedarach and Solanum incanum was scientifically justified based on their well-documented traditional medicinal uses and previous reports of antimicrobial activity. Ethical approval was obtained from the Kabarak University Research Ethics Committee (KUREC), and a research permit was obtained from the National Commission for Science, Technology, and Innovation (NACOSTI). The results demonstrated significant anti-staphylococcal activity for both extracts, with Melia azedarach exhibiting superior efficacy compared to Solanum incanum at all concentrations tested. Moreover, the combined extracts displayed enhanced antimicrobial effects against Staphylococcus aureus compared to the individual extracts. Phytochemical analysis revealed the presence of tannins, coumarins, flavonoids, and anthraquinones in both extracts, with higher levels of steroidal glycosides in Solanum incanum. We recommend further phytochemical and pharmacological investigations to identify the active antimicrobial constituents in these plants. These findings hold promise in the development of novel therapeutic agents to combat infectious diseases, offering Melia azedarach and Solanum incanum as potential sources for drug development.