Antimicrobial Activities of some Plant Extracts against Phytopathogenic Fungi and Clinical Isolates in Iran

Natural products from plants as environmentally safe options have received attention for controlling various phytopathogenic diseases. In this study, the antimicrobial activities of three plant aqueous and alcoholic extracts (Salvia officinalis, Peganum harmala and Oxalis corniculata) against phytopathogenic fungi (10 fungal isolates associated with diseased tomato fruits) and clinical isolates (10 bacterial isolates) and Candida albicans, as a pathogenic yeast model, were investigated in the Gilan province of northern Iran.

After phytochemical screening of plant extracts, antimicrobial activity of the extracts evaluated by standard methods for determination of MIC and MBC. Results of the phytochemical screening of aqueous and alcoholic leaf extracts of the selected three plants revealed the presence of saponins, steroids, tannins, glycosides, alkaloids and flavonoids.

All three extracts of the plants tested showed varying degrees of antimicrobial activities against both phytopathogenic fungi and bacteria. Generally, the methanol extracts were more active than other extracts for S. officinalis and P. harmala, whereas for O. corniculata water extract showed more antimicrobial activity.

The study has been able to establish and document the important medicinal plants which can be used in the management of phytopathogens and infectious diseases in Iran