The current study was conducted to prepare different polarities extracts and evaluate their antimicrobial and cytotoxic activities from the aerial parts of Cleome austroarabica (C. austroarabica) which was collected from the initial campus of the University of Nizwa. The coarse powder was extracted with direct methanol by using a maceration method. The extract residue was fractionated by using various organic solvents with increasing polarity. The agar disc and brine shrimp lethality (BSL) bioassays were used to assess the antimicrobial and cytotoxic activities of the aerial extracts of C. austroarabica. Four concentrations (2000, 1000, 500, 250 mg/ml) of each extract were used to determine the antimicrobial activity against two Gram (+) bacteria: Staphylococcus aurous (S. aurous), Enterococcus faecalis (E. aurous) and two Gram (
) bacteria: Haemophilus Influenza (H. Influenza), and Escherichia coli (E. coli). Brine shrimp organisms were used to assess the cytotoxic activities of various polarities aerial extracts and the fractions of chloroform extract. The antimicrobial activity results showed that all polarities extracts at different concentrations did not give any activity against the tested bacteria. The cytotoxic activity of all polarities aerial extracts displayed activity within the value of LC50 385.25–640.25 lg/ml in the order of chloroform > hexane > hydro alcoholic > ethyl acetate > methanol extract. However, the isolated all chloroform fractions showed high LC50 activity compared to control. The further extensive study will be needed to confirm the antimicrobial and cytotoxic activities of the crude extracts and to isolate the active ingredients from the highest activity aerial extracts.

The current study was conducted to prepare different polarities extracts and evaluate their antimicrobial and cytotoxic activities from the aerial parts of Cleome austroarabica (C. austroarabica) which was collected from the initial campus of the University of Nizwa. The coarse powder was extracte...