Evaluation of Antibacterial Activity of Tribulus terrestris L. Growing in Iran

Tribulus terrestris is used as a urinary anti-infective in folk medicine. To validate this use, the in vitro antibacterial activity of methanolic extracts of different parts (fruits, stems plus leaves and roots) of T. terrestris L. growing in Iran was evaluated against four reference bacteria by broth dilution assay and agar diffusion assay. The MIC value of the methanolic extracts of fruits and stems plus leaves against all bacteria was 2 mg/mL and the MIC value of roots against S. aureus, E. faecalis and E. coli was 4 mg/mL and the MIC value of roots against P. aeruginosa was 2 mg/mL. In agar diffusion assay, the methanolic extracts of all parts of the plant showed considerable activity against all bacteria.