Journals Proceedings

Abstract

Plants contain natural products which have been recognized as building blocks for primary health care. Sterculiar tragacantha Lindl, used traditionally in Nigeria for the treatment of boils, diarrhea, gonorrhea, edema, gout, whitlow, fevers and malaria is one of such plants. The prevalence of drug resistant pathogenic microbes as well as the oxidative damage to cells by excess free radicals that lead to degenerate diseases, constitute major health hazards to man. In this regard, extracts of the stem bark of S. tragacantha Lindl was investigated for their toxicity to brine shrimps and ability to scavenge hydroxyl radical and inhibit microbial growth. Air dried and ground stem bark of the plant was extracted with methanol and partitioned in n-hexane and ethyl acetate. Hydroxyl radical scavenging assay of the three extracts obtained revealed that the percentage inhibition for all the extracts was above 90% at 0.625 mg/ml which is higher than that of one of the antioxidant standard (ascorbic acid) used for the assay. The ethyl acetate and methanol extracts were toxic with LC50 value of 487.03 μg/ml and 482.80 μg/ml respectively, while the hexane was non toxic with LC50 value >1000 μg/ml in the brine shrimp lethality test. Bioactive compounds have been found to be often toxic to shrimp eggs. All the extracts demonstrated activity against the ten microbes: Staphylococcus aureus, Esherichia coli, Bacillus subtilis, Pseudomonas aerugunosa, Salmonella typhi, Klebsiellae pneumonia, Candida albicans, Aspergillus niger, Penicillum notatum, Rhizopus stolonifer used in the antimicrobial assay. Preliminary phytochemical screening revealed the presence of saponin, tannins, alkaloids, phenols, cardiac glycosides, resins and antraquinones as the secondary metabolites present in the extracts. The ability of the extracts to scavenge hydroxyl radicals and inhibit growth of microorganisms makes the plant a potential source of antioxidant and antimicrobial compounds and also validates the ethno medicinal use of Sterculiar trangacantha Lndl.