Antibacterial and cytotoxic antibacterial potential of ethanol extract and fractions from Aristolochia galeata Mart. ex Zucc

Abstract

The aim of this investigation was to evaluate the phytochemical, antibacterial and cytotoxic activities of ethanol extract and hexane, dichlorometane, ethyl acetate and hydroethanolic fractions from Aristolochia galeata’s rhizomes. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were evaluated by the broth microdilution assay to investigate the antibacterial activity of various extracts and fractions of A. galeata against Gram-positive and Gram-negative bacteria. The cytotoxicity of plant samples was evaluated in human cervix carcinoma cell line (HeLa) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. The phytochemical study showed the presence of main secondary metabolites, steroids, flavonoids, coumarins and alkaloids. The ethanol extract and their fractions presented antimicrobial activity against Gram-positive bacteria, and Staphylococcus aureus was regarded the most sensitive strain with MIC of 250 µg/ml for the ethanol extract. The dichlorometane fraction showed bactericidal activity with the value of 1250 µg/ml and moderate cytotoxicity in front of the HeLa cell line tested (CC50 = 90 µg/ml). The results showed that A. galeata had effective antibacterial activity against Gram-positive bacteria and compounds extracted from A. galeata Mart. ex Zucc could be used as possible antimicrobials. The good antimicrobial activity and the low cytotoxicity presented by the hexane fraction can be promised for the new molecules with antibiotic activity. Key words: Aristolochia galeata, antibacterial activity, minimal inhibitory concentration, cytotoxic activity, phytochemistry.