In Vitro Evaluation of the Cytotoxic, Antioxidant, and Antimicrobial Activities of Azadirachta indica Leaf Extracts

Azadirachta indica is a medicinal plant with potential therapeutic applications. This study evaluated the in vitro cytotoxic, antioxidant, antibacterial, and antifungal activities of its leaf fractions obtained using n-hexane, chloroform, ethyl acetate, and methanol. Cytotoxicity was assessed using the brine shrimp lethality assay, while antioxidant activity was determined using the DPPH radical-scavenging assay. Antimicrobial activity was evaluated against Escherichia coli, Staphylococcus aureus, Aspergillus fumigatus, and Mucor spp. The chloroform fraction exhibited the lowest estimated LC₅₀ (151.6 µg/mL), indicating the greatest cytotoxicity. The n-hexane fraction showed the strongest antioxidant activity among the extracts, with an IC₅₀ of 87.50 µg/mL. Ethyl acetate demonstrated the highest antibacterial activity against E. coli (14.0 mm) and S. aureus (11.0 mm). The n-hexane fraction showed the greatest inhibition of A. fumigatus (9.0 mm). These findings indicate solvent-dependent biological activities warranting further investigation