Antibacterial activity of eight medicinal plants against Diarrhoea pathogens

The studies involve the phytochemical screening and antibacterial activity of leaf extracts eight medicinal plants. The selected plants were Timarindus indica, Guiera senegalensis, Prosopis africana, Deterium  microcarpum, Citrus aurantifolia, Psidium guajava, Acacia nilotica and Momordica charantia. Methanolics  and aqueous leaf extracts revealed the presences of alkaloids, tannins, phenols and flavonoid in high  amount in most of the plants. Volatile oil was only detected in C. aurantifolia. Clinical isolates of Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Citrobaceter sp. were tested for susceptibility to the extracts. The methanolic and aqueous extracts of P. africana  exhibited high antibacterial activity with 100% inhibition of all isolates. D. microcarpum showed 100% and 50% activity for aqueous and methanolic extracts respectively while the aqueous extract of G. senegalensis and A. nilotica showed 83.5% inhibition. The MIC and MBC was determined only on the extract that exhibited high activity (10-20mm zones of inhibition) on the tested organisms. The MIC of highly active extract of P. africana and aqueous of G. senegalensis and D. microcarpum were observed to be lower for all isolate (0.156mg/ml - 0.625mg/ml) than the less active extract (2.5mg/ml and 10-40mg/ml). the results obtained in this study shows that P. africana, G. senegalensis, D. microcarpum and T. indica are potentials sources of antimicrobial agents.Keywords: Antibactrial activity, Medicinal plants, Diarrhoeal patogens, Selected plants, Phytochemical screening

Inhibitory activity of xanthine oxidase by fractions Crateva adansonii

Objective: To study the inhibitory effect of various extracts from Crateva adansonii (C. adansonii) used traditionally against several inflammatory diseases such as rheumatism, arthritis, and gout, was investigated on purified bovine milk xanthine oxidase (XO) activity. Methods: Xanthine oxidase inhibitory activity was assayed spectrophotometrically and the degree of enzyme inhibition was determined by measuring the increase in absorbance at 295 nm associated with uric acid formation. Enzyme kinetics was carried out using Lineweaver-Burk plots using xanthine as the substrate. Results: Among the fractions tested, the chloroform fraction exhibited highest potency (IC50 20.2±1.6 μg/mL) followed by the petroleum ether (IC50 30.1±2.2 μg/mL), ethyl acetate (IC50 43.9±1.4 μg/mL) and residual (IC50 98.0±3.3 μg/mL) fractions. The IC50 value of allopurinol used, as the standard was 5.7±0.3 μg/mL. Conclusions: Enzyme inhibition mechanism indicated that the mode of inhibition was of a mixed type. Our findings suggest that the therapeutic use of these plants may be due to the observed Xanthine oxidase inhibition, thereby supporting their use in traditional folk medicine against inflammatory-related diseases, in particular, gout