Antimicrobial and phytochemical studies on 45 Indian medicinal plants against multi-drug resistant human pathogens

Ethanolic extracts of 45 Indian medicinal plants traditionally used in medi cine were studied for their antimicrobial activity against certain drug-res istant bacteria and a yeast Candida albicans of clinical origin. Of these, 40 plant extracts showed varied levels of antimicrobial activity against on e or more test bacteria. Anticandidal activity was detected in 24 plant ext racts. Overall, broad-spectrum antimicrobial activity was observed in 12 pl ants (L. inermis, Eucalyptus sp., H. antidysentrica, H. indicus, C. equisti folia. T. belerica, T. chebula, E. officinalis, C. sinensis, S. aromaticum and P. granatum). No correlation was observed between susceptibility of tes t strains with plant extracts and antibiotic resistance behaviour of the mi crobial strains (Staphylococcus aureus, Salmonella paratyphi, Shigella dyse nteriae, Escherichia coil, Bacillus subtilis, Candida albicans). Qualitativ e phytochemical tests, thin layer chromatography and TLC-bioautography of c ertain active extracts demonstrated the presence of common phytocompounds i n the plant extracts including phenols, tannins and flavonoids as major act ive constituents. (C) 2001 Published by Elsevier Science Ireland Ltd.