Antimicrobial screening of ethnobotanically important stem bark of medicinal plants

The stem barks are the rich sources of tannins and other phenolic compounds. Tannins inhibited the growth of various fungi, yeast, bacteria and virus. Hence, ten stem barks of ethnomedicinally important plants were screened for antibacterial and antifungal activities against human pathogenic strains. Air-dried and powdered stem bark of each plant was extracted with 50% aqueous ethanol, lyophilized and the dried crude extracts were used for the screening against 11 bacteria and 8 fungi. Antibacterial and antifungal activities were performed according to microdilution methods by NCCLS. The plants Prosopis chilensis, Pithecellobium dulce, Mangifera indica showed significant antibacterial and antifungal activities against Streptococcus pneumonia, Enterobacter aerogenes, Klebsiella pneumonia and Candida albicans with MIC of 0.08mg/ml. Pithecellobium dulce bark also showed significant antibacterial activity against Bacillus cereus. The bark of Pithecellobium dulce has more or less similar activity against the known antibiotic and may be considered as potent antimicrobial agent for various infectious diseases.