Investigated inhibitory effect of aqueous extract of pistachio leaf (Pistacia atlantica) on the isolates of pathogenic Escherichia coli and Candida albicans from urinary and vaginal samples

Pistacia atlantica is one of the medicinal plants native to Iran and known for its antimicrobial properties. Therefore, the present study aimed to investigate the antibacterial and antifungal effects of the aqueous extract of P. atlantica leaves on clinical isolates of Escherichia coli and Candida albicans in vivo.

In this descriptive-cross-sectional study, the minimum inhibitory concentration (MIC) and minimum bactericidal/ fungicidal concentration (MBC/MFC) of aqueous extract of pistachio leaf were determined on 60 isolates of E. coli and 60 isolates of C. albicans, according to CLSI protocol at concentrations of 0.125-100 mg/ml. The obtained results were analyzed using R software at a significance level of 0.05.

The mean minimum inhibitory concentrations of coriander extract for E. coli and C. albicans clinical isolates were obtained at 45.3±1.0 and 43.7±1.1 mg/ml, respectively. The comparison of the minimum concentration of growth inhibitor and lethality of clinical isolates with standard E. coli strain was not significantly different (P=0.65); nonetheless, the standard strains of C. albicans were significantly different from the clinical isolates of this fungus (P<0.001).

As evidenced by the results of the present study, the aqueous extract of P. atlantica leaves has inhibitory effects on the clinical isolates of E. coli and C. albicans. Therefore, it is possible to use the aqueous extract of this plant in isolation or in combination with other drugs to treat urinary tract and vaginal infections.