Biological screening of seventeen medicinal plants used in the traditional systems of medicine in Pakistan for antimicrobial activities

Abstract

Antibacterial properties of 51 aqueous, ethanolic and n-hexane extracts of seventeen medicinal plants from fourteen families used in the traditional system of medicines in Pakistan were tested against ten commonly prevalent gram negative and gram positive bacteria. In particular we examined the enteric pathogens and yeast using agar well diffusion method. The extracts of Eucalyptus globulus, Emblica officinalis and Sphaeranthus were found to have high levels of activity against all ten of the microorganisms. Ethanolic extracts of Azadirecta indica, Cedrella toona, Punicia granatum, Berginia ciliata and Lawsonia alba have shown considerable activity. Aqueous extracts of B. ciliata, L. alba and P. granatum have also shown low to moderate antimicrobial activity. The hexane extracts of the other fourteen medicinal plants and extracts from Calotropics procera, Melia azdirecta, Myrtus communis, Berberis aristata, Aspholedus tinuipholius had either no activity against most of the organisms or moderate activity against few organisms. Antibacterial activity of some of these plant extracts was comparable with commercially available antibiotics. Pakistan has a rich flora with broad potential for new antimicrobial agents which can be used as a substitute for current antibiotics against which wide spread resistance has developed. Key words: Antimicrobial properties, crude extracts, Pakistani medicinal plants.