Introduction: Tribulus was traditionally used as a diuretic, mild laxative, urolithiasis, dysurea for treatment of urinary tract problems including stones, cystitis and infections, particularly Gonohrea. Antimicrobial effects of methanol extract of Tribulus fruit on few gram positive and negative bacteria, the causative agents of some bacterial infections was evaluated and then compared with some in use antibiotics for these infections.
Materials and Methods: In this research as an experimental study, 40 gr powder of Tribulus fruit was dissolved in 100 ml pure methanol as a solvent with cold maseration method, the suspension was filtered after 5 day. The filtered suspension was concentrated with rotary evaporator apparatus in vaccum and was then dilluted with methanol to yield different concentrations. The antimicrobial activity of the extract and antibiotical were examined with disc diffusion and tube dilution standard methods to measure the diameter of inhibition zones, minimal inhibitory concentra tion and minimal bacterial concentration.
Results: The results were shown that the antimicrobial effect of the methanol extract of Tribulus fruit on ATCC strains of Streptococcus faecalis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeroginosa had bactriostatic effect with the concentration of 400, 200, 100, 100 µg / ml in order. The comparison of urinary tract infections, including Oxacilin, Ciprofloxacin, Penicilin G, Gentamycin, Cotrimoxazole, Nalidixic acid and Nitroforantoin were shown that Tribulus fruit extract in concentration used in this research had a similar or even better effect than some antibiotics on some of the bacteria used in this evaluation.
Conclusion: The Tribulus fruit extract has an efficient bactriostatic and bactricidal activity of few gram positive and negative bacteria, the causative agents of some bacterial infections and these effects are comparable to those antibiotics in use for treatment of these infections. Tribulus fruit extract could be suggested for treatment of these infections after the pharmacological and clinical complementary studies.