In vitro Antibacterial Activity of Ethanolic Extract of Equisetum arvense L

The ethanolic extract of stem from Equisetum arvense L was analyzed to find out the antibacterial activity against two Gram positive (Bacillus subtilis and Micrococcus luteus) and four Gram negative (Vibrio cholerae, Escherichia coli, Shigella flexneri and Shigella dysenteriae) bacteria. The antibacterial activity (measured by zoneof inhibition) for the extract increased with the increasing concentration of the extract. E. coli showed maximum sensitivity (inhibition zone 32 mm) among all the bacteria studied. Both Gram positive and Gram negative bacteria were found to be sensitive indicating the broad spectrum activity of the extract. Shigella dysenteriae and Vibrio cholerae were insensitive to the extract. Preliminary phytochemical screening indicated the presence of phenolics, tannins, glycosides, alkaloids, saponins, terpenoids and flavonoids.