Antimicrobial and Preliminary Cytotoxic effects of Ethanol extract and its fractions of Anthocephalus cadamba (Roxb.) Miqstem bark

Abstract

Anthocephalus cadamba(Roxb.) Miq, Rubiaceae, is an important Bangladeshi medicinal plant for its traditional uses against different types of diseases. Therefore, the present study investigated for its potential antimicrobial and cytotoxic activities of petroleum ether (pet. ether) and chloroform fractions of ethanol extract of Anthocephalus cadamba stem bark. The antimicrobial potentialities were evaluated by disc diffusion method against four Gram-positive, six Gram-negative bacteria and six species of fungi at a concentration 500 µg/disc.Kanamycin 30 µg/disc was used as the standard drug. The chloroform fraction showed maximum activity against almost all bacteria. Shigella dysenteriae, Escherichia coli and Pseudomonus aeruginosa showed better sensitivities to chloroform fraction with the zone of inhibition 24.1, 22.3 and 22.1 mm respectively while pet. ether fraction showed mild sensitivities. Bacillus cereus and Klebsiella pneumonia were two bacteria amongst ten showed lowest activities to the extracts. In case of antifungal activity screening, the chloroform fraction induced significantzone of inhibition16.6, 15.7 and 13.2 mm by Aspergillus flavus, Candida albicans and Aspergillus niger.These two fractions were subjected to brine shrimp lethality test to evaluate cytotoxicity. The LC₅₀values for pet. ether, chloroform fractions and standard vincristine sulphate were 17.78, 15.66 and 12.02µg/ml respectively.The present study revealed that chloroform fractions of ethanol extracts of stem bark possess potent antimicrobial activities along with moderate cytotoxicities that may lead to new drug development.