Antibacterial and phytochemical studies of Euphorbia hirta Linn. against respiratory tract pathogens

Euphorbia hirta was evaluated for antibacterial activity against human pathogenic bacterial strains. Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae causing respiratory tract infections. Petroleum ether, acetone, methanol and water extracts of E. hirta were screened for antibacterial activity by cup-plate method at sample concentration of 200 mg/ml. The result of antibacterial activity revealed that methanolic extracts of the plant exhibited maximum activity as compared to petroleum ether, acetone and water. Minimum inhibitory concentration (MIC) of the methanolic extract of the plant was also calculated against the pathogens. S. aureus was the most susceptible bacteria. Phytochemical screening of the extracts revealed the presence of alkaloids, flavonoids, tannins, phenolics, saponins, glycosides, amino acids and steroids. The presence of these bioactive constituents has been linked to the antimicrobial activity of the plant.