ABSTRACT
BACKGROUND: Casuarina equisetifolia belongs to the Casuarina species with the most extensive natural distribution, which contain various phytochemicals with potential health benefits. This study aimed to investigate the chemical composition and biological activities of different extracts of Casuarina equisetifolia. METHODS: The n-hexane extract was analyzed for its unsaponifiable and fatty acid methyl esters fractions, while chloroform, ethyl acetate, and butanol extracts were studied for their phenolic components. Six different extracts of C. equisetifolia needles were evaluated for their total phenolic content, total flavonoid content, and their antioxidant, antimicrobial, and cytotoxic activities. RESULTS: The n-hexane extract contained mainly hydrocarbons and fatty acid methyl esters, while ten phenolic compounds were isolated and identified in the chloroform, ethyl acetate, and butanol extracts. The methanolic extract exhibited the highest total phenolic and flavonoid content, highest antioxidant activity, and most potent cytotoxic activity against HepG-2 and HCT-116 cancer cell lines. The ethyl acetate extract showed the most significant inhibition zone against Staphylococcus aureus and Bacillus subtilis. CONCLUSION: Casuarina equisetifolia extracts showed promising antioxidant, antimicrobial, and cytotoxic activities. Overall, Casuarina equisetifolia is a versatile tree with a variety of uses, and its plant material can be used for many different purposes.