Antimicrobial effect of different extracts of Nerium oleander L on standard and clinically isolated microorganism

In folk medicine, Nerium oleander L is used as cardiotonic, diuretic and as local in treating fungal infections. In this research the antimicrobial and antifungal effects of Nerium oleander was studied. In this study, aqueous, methanol and chloroform extracts were prepared by maceration and soxhelet methods. Different concentrations of each extract were applied on standard and nosocomial microorganisms by agar dilution, disk and cylinder plate methods. Microorganisms such as S. aureus, P. aerogenosa and C. albicans were taken from blood, feces, spinal fluid, wound, vagina and so on. Cloxacillin, gentamicin and clotrimasol were used as positive controls. The results showed that, among extracts, methanol extract had significant antimicrobial and antifungal effects, which was comparable to that of standard antibiotics. Chloroform extract showed no effect. Effect of methanol extract on microorganisms was as follow; 500mg/100ml of extract was equal to 1mg/100ml cloxacillin on S. aureus and 2mg/100ml gentamicin on P. aerogenosa respectively. 2g/100ml of extract was equal to 0.4mg/100ml clotrimasol on C. albicans. The methanol extract of Nerium oleander exerts significant effect compare to standard drugs.