In vitro antimicrobial activity and preliminary phytochemical screening of some plant extracts

Abstract

Antimicrobial activity of five solvent extracts of local plants was evaluated in vitro, with four strains of bacteria viz., Salmonella typhi, Escherichia coli, Shigella flexneri (gram -ve), Staphylococcus aureus (gram +ve) and four strains of fungi viz., Alternaria alternata, Penicillium notatum, Aspergillus niger, Penicillium digitatum microorganism. The in vitro antibacterial and antifungal activities were tested by agar disc diffusion method. The most active antibacterial plants were Vitex negundo, Tagetes erecta and antifungal plants were Xanthium strumarium, Vitex negundo and Tagetes erecta, respectively. The significant antimicrobial activities of potent extracts were compared with the standard antimicrobiotics, Ciprofloxacin and Fluconazole for bacteria as well as fungi respectively at 1 mg/ml concentration. Preliminary phytochemical analysis of V. negundo leaf, X. strumarium, M. pruriens, C. bonduc seed and T. erecta flower extracts generally revealed the presence of Alkaloids, Steroids, Terpenoids, Phenols, Saponins, Anthraquinones, Amino acids, Carotenoids, Flavonoids and Tannins at various concentrations. The results obtained in this study suggest that X. strumarium, V. negundo, T. erecta can be used in treating diseases caused by these test organisms.