Evaluation of antimicrobial potential of successive extracts of Ulmus wallichiana Planch

BACKGROUND: The plant Ulmus wallichiana Planch. is found in hills of Uttarakhand, India. Bark of U. wallichiana is commonly used as traditional healer for bone fracture of animals as well as human beings and also used as wound healer remedy. OBJECTIVE: The present study was designed to evaluate antimicrobial potential of various extracts of U. wallichiana bark. MATERIALS AND METHODS: Soxhlet extraction method was used for preparation of different extracts viz. petroleum ether, chloroform, ethyl acetate, ethanol and aqueous. Antioxidant activity was determined by DPPH and FRAP assay method. In vitro antimicrobial activity was evaluated using agar well diffusion method. RESULTS: Ethyl acetate extract exhibited the highest significant antioxidant activity. Antibacterial activity was performed against Escherichia coli, Bacillus subtilis, Staphylococcusaureus and Pseudomonas aeruginosa. Amongst the various extracts tested, only ethyl acetate exhibited highest zone of inhibition as compared to other extracts and greater than standard drug. Chloroform extract also showed moderate zone of inhibition. Antifungal activity was evaluated against Aspergillus fumigates and Aspergillus flavus. The ethyl acetate extract showed maximum zone of inhibition as compared to other extracts. Chloroform extract showed mild antifungal activity. Chloramphenicol and nystatin were used as a positive control as antibacterial and antifungal agent respectively. Furthermore, the highest percentage of phenolic and flavonoid compounds was estimated in ethyl acetate extract. CONCLUSION: The ethyl acetate extract of U. wallichiana showed the highest antimicrobial activity, and should be further investigated for isolating active compound(s) responsible for antimicrobial activity.