ANTIMICROBIAL POTENCY AGAINST MICROBES FOUND IN CLINICAL SAMPLES AND TOXICITY STUDIES ON SELECTED MEDICINAL PLANTS

The antib acterial and antifungal activi ties of Terminalia arjuna, Tephrosia purpurea and Thuja occidentalis extracts w ere investigated against the standard drugs , which are presen tly available in the market as G entam i cin, Cephradine , Amoxicillin c lavulanate, Norfloxacin and Itraconazole . W ell m ethod was used for antimicrobial activity and the zone s of inhibition were measured in m illi m eters . The antibacterial activity was observed on three gram negative bacteria i.e. Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa and one gram positive bacteria i.e. Staphy lococcus aureus . The antifungal activity was investigat ed against Candida albicans and Aspergillus niger . The cytotoxic effects (LD 50 ) of the crude extracts we re also observed on brine shrimps ( Artemia salina ) using E toposide a s an internal standard . The crude extract of T . arjuna bark exhibited less potent antimicrobial activity as compare d to crude extract of T . arjuna heart wood. Bark extract of T. arjuna show ed no cytotoxic activity but heart wood extract sho w ed this activit y in b rine s hrimp b ioassay technique . The crude extract of T . purpurea show ed positive cytotoxic, potent antibacterial but no antifungal activity . The crude extract of T . occidentalis show ed good antibacterial low antifungal and low cytotoxic activity. T. arjuna showed most potent antimicrobial and cytotoxic activity while T. Purpurea and T. oocidentalis posses less potent activities.