Phytochemical screening and antimicrobial efficacy of Alternanthera nodiflora extracts

The phytochemical constituents and antimicrobial activities of Alternanthera nodiflora extracts were analyzed. Plant sample was extracted using methanol and water. Qualitative phytochemical screening revealed the presence of alkaloids, carotenoid, flavonoids, terpenoids, cardiac glycosides, phenols and saponins while tannins were absent in both extracts. The antimicrobial potential of the extracts was tested against Staphylococcus aureus, Escherichia coli and Salmonella typhi, Candidaalbicans and Aspergillus niger. The Susceptibility patterns of the test organisms to varying concentrations (100mg/ml, 75mg/ml, 50mg/ml and 25mg/ml) of both extracts were determined by Kirby Bauer method. From this study, antimicrobial activity of the plant extracts was highest at 100mg/ml with Methanolic extract having more antimicrobial activity than aqueous extract. The extracts showed high activity against Candida albicans but no activity was observed against Aspergilus niger while the highest antibacterial activity of the extract was observed against Staphylococcus aureus.The higher antimicrobial activity in methanolic extract than aqueous extracts could be attributed to the degree of polarity of the extraction solvent.Key words: Alternanthera nodiflora, Phytochemicals, Antimicrobial activity, Extracts.