Antimicrobial activity of a plant anthocyanine against some human pathogens

Phytochemicals are secondary metabolites produced by medicinal plants. Some haveshown significant antimicrobial activity to disease causing bacteria’s that have developed resistance strains to synthesized drugs. Therefore this investigation is aimed atinvestigating the antimicrobial property and to confirm the growth inhibitory activity of anthocyaninfrom Phyllanthus muellerianus plant leaves extract against human pathogen such as Escherichia coli, Staphylococcus aureus, and Salmonella typhi. Spectroscopic (UV/Vis, FT-IR and 1H NMR) techniques were employed in characterization, while disc diffusion method was used for antimicrobial property and to confirm the growth inhibitory activities.UV-Vis absorption spectrum shows peaks at 313 nm and 482 nm being attributes of anthocyanin. According to FT-IR and 1H NMR investigations the tested sample have cyanidin glycoside and peonidin glycoside. Phyllanthus muellerianus plant leaves extractdemonstrated promising activity against the test organisms. The extract exhibits activity on all the test organisms producing zones of inhibition ranging from 11-18mm. The activity was more pronounced (MIC 4.0 mg/mL) against S. typhi while the least activity was against E. coli (MIC 50mg/mL). However, the S. typhi and E. coli were inhibited in all concentration of extract assayed respectively. The minimum inhibition concentration (MIC) showed that the extract had lowest MIC value (4.0 mg/mL) against S. typhi.This investigation therefore supports the traditional medicinal use of P. muellerianus leaves as a source of antimicrobial agents.