Antibacterial Screening and Brine Shrimp (Artemia salina) Toxicity of Securidaca Longepedunculata (Polygalaceae) Root Bark

Abstract

This study was undertaken to investigate, the antibacterial activities of crude water and ethanolic extracts of Securidaca longepedunculata root bark on six bacterial strains (Salmonella typhimurium, Klebsiella sp., Escherichia coli, Staphylococcus areus, Pseudomonas aeroginosa, and Shigella).  Standard methods, which revealed the potential for antibacterial activity against the tested organisms, were used. The result of phytochemical screening demonstrated the presence of steroid, flavonoids, cynogenic, glycoside, anthraquinones, and flavotannin in the solvents used. The alkaloids were only present in the ethanol extract, while Saponin was found in water extract alone. Thin layer chromatography demonstrated four and two spots for ethanol and aqueous extracts respectively.  Aqueous water had the highest percentage yield of 12.6%, when compared with that of the ethanol extract at 10%. The brine shrimp lethality assay, was associated with various degrees of toxicity.  LC₅₀ of 0.32 µg/ml was associated with mortality rate of 100%, 93%, and 83% for the 1000,100, and 10 μg/ml concentrations prepared respectively.  The crude water extract had LC₅₀ of 3.01 µg/ml, with 100%, 83%, and 70% mortality rates for these concentrations, with a 95% confidence interval.