title: Breaking the resistance of Escherichia coli: Antimicrobial activity of Berberis lycium Royle.
abstract: The antimicrobial activity of root bark of Berberis lycium and its principal component berberine was tested against a panel of microbial strains using agar well diffusion test and further analyzed using micro-broth dilution method. Preliminary analysis, on the basis of zone of Inhibition (ZOI) showed that the methanolic extract of B. lycium was highly effective against Escherichia coli (ZOI 41 ± 1 mm). Among the bacterial strains E. coli was found to be most susceptible and among fungi Candida albicans was the most susceptible for berberine as well as the crude methanolic extract of the plant. Methanolic extract of the plant was more effective for E. coli (MIC 1.7 ± 1.18; MBC 2.4 ± 1.18) than berberine (MIC 3.5 ± 0.57) (p < 0.05), whereas berberine was more effective than crude extracts for C. albicans. In addition, E. coli showed the development of resistant colonies after 72 h when tested with berberine but the development of such colonies was not observed with the methanolic extract of the plant. This could be due to the presence of resistance breaking molecules in the crude methanolic extract of B. lycium. Also the MIC index of crude methanolic extract was 1.39 for E. coli, which showed the mode of action to be bactericidal. HPLC analysis revealed the presence of berberine at highest concentration in methanolic extract of the plant, followed by aqueous extract. Potentiation of this berberine by resistance breaking molecules in the crude extract could be a possible explanation for its strong effectiveness.
authors.affiliation: Centre of Research for Development, University of Kashmir, Srinagar, J&K, India. Electronic address: maliktsf@gmail.com.
authors.forename: Tauseef Ahmad
authors.initials: TA
authors.lastname: Malik
authors.affiliation: Centre of Research for Development, University of Kashmir, Srinagar, J&K, India.
authors.forename: Azra N
authors.initials: AN
authors.lastname: Kamili
authors.affiliation: Centre of Research for Development, University of Kashmir, Srinagar, J&K, India.
authors.forename: M Z
authors.initials: MZ
authors.lastname: Chishti
authors.affiliation: Department of Zoology, University of Kashmir, Srinagar, J&K, India.
authors.forename: Shazia
authors.initials: S
authors.lastname: Ahad
authors.affiliation: Centre of Research for Development, University of Kashmir, Srinagar, J&K, India.
authors.forename: Mudasir A
authors.initials: MA
authors.lastname: Tantry
authors.affiliation: Astrophysical Sciences Division, Nuclear Research Laboratory, BARC, Zakura, Srinagar, J&K, India.
authors.forename: P R
authors.initials: PR
authors.lastname: Hussain
authors.affiliation: PK-PD Toxicology Division, Indian Institute of Integrative Medicine (CSIR), Jammu-Tawi, J&K, India.
authors.forename: R K
authors.initials: RK
authors.lastname: Johri
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology; D028142:Berberis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects*; D005658:Fungi / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D010936:Plant Extracts
keywords: Antimicrobial resistance; Berberine; Berberis lycium; HPLC