Brine shrimp lethality and antibacterial activity of extracts from the bark of Schleichera oleosa

Objective:To determine the antibacterial efficacy and brine shrimp toxicity of extracts(hexane,dichloromethane,ethyl acetate,methanol and water)obtained from the bark of Schleichera oleosa.Methods:The powdered bark sample was Soxhlet extracted sequentially in hexanes,dichloromethane,ethyl acetate,methanol and water.Antibacterial evaluation was carried out by following the agar diffusion method and amoxicillin disc was used as a reference.Slightly modified Meyer’s method was used to determine the toxicity of the extracts in brine shrimps.Results:Among the nine bacterial strains tested,the methanolic and aqueous extracts showed promising antibacterial efficacy against Serratia marcescens,Escherarichia coli,Bacillus subtilis and Micrococcus luteus.None of the extracts were found significantly toxic to brine shrimps.Conclusions:Strong antibacterial activity and low brine shrimp toxicity of methanolic and aqueous extracts can provide new antibacterial compounds.