RESUMEN
Aims: To determine antioxidant, cytotoxic and antimicrobial activities of organic extracts from leaves of Acridocarpous orientalis (qafas) from Sultanate of Oman. Study Design: Brine shrimp test, DPPH assay and Disc diffusion method. Place and Duration of Study: School of Pharmacy, University of Nizwa, Oman, December 2012. Methodology: Hexane, chloroform, ethylacetate and hydroalcoholic extract were obtained by Kupchan’s partitioning of ethanol extract isolated from leaves of A. orientalis by maceration. Antioxidant activity was determined by free radical scavenging of (2,2- diphenyl-1-picrylhydrazyl, DPPH). The antimicrobial activity was checked using agar disc diffusion method against Gram-positive bacteria (Staphylococcus aureus) and two Gramnegative bacteria (Escherichia coli and Pseudomonus aeruginosa). Brine shrimp test was used to measure cytotoxic activity. Results: All extracts demonstrated potential antioxidant activities, hydroalcoholic extract showed the strongest activity (RC50 = 6.11 g/ml). The order of antioxidant activity was hydro alcohol > ethyl acetate > chloroform > hexane extract. Ethylacetate extract showed low activity against Pseudomonus aeruginosa. None of the extracts was found to be active against brine shrimp larvae. Conclusion: A. orientalis could be considered as a good source of antioxidant compounds.