title: Antimicrobial Activities of Methanol, Ethanol and Supercritical CO2 Extracts of Philippine Piper betle L. on Clinical Isolates of Gram Positive and Gram Negative Bacteria with Transferable Multiple Drug Resistance.
abstract: Piper betle L. has traditionally been used in alternative medicine in different countries for various therapeutic purposes, including as an anti-infective agent. However, studies reported in the literature are mainly on its activities on drug susceptible bacterial strains. This study determined the antimicrobial activities of its ethanol, methanol, and supercritical CO2 extracts on clinical isolates of multiple drug resistant bacteria which have been identified by the Infectious Disease Society of America as among the currently more challenging strains in clinical management. Assay methods included the standard disc diffusion method and the broth microdilution method for the determination of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentrations (MBC) of the extracts for the test microorganisms. This study revealed the bactericidal activities of all the P. betle leaf crude extracts on methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii, with minimum bactericidal concentrations that ranged from 19μg/ml to 1250 μg/ml. The extracts proved to be more potent against the Gram positive MRSA and VRE than for the Gram negative test bacteria. VRE isolates were more susceptible to all the extracts than the MRSA isolates. Generally, the ethanol extracts proved to be more potent than the methanol extracts and supercritical CO2 extracts as shown by their lower MICs for both the Gram positive and Gram negative MDRs. MTT cytotoxicity assay showed that the highest concentration (100 μg/ml) of P. betle ethanol extract tested was not toxic to normal human dermal fibroblasts (HDFn). Data from the study firmly established P. betle as an alternative source of anti-infectives against multiple drug resistant bacteria.
authors.affiliation: Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines.
authors.forename: Demetrio L
authors.initials: DL
authors.lastname: Valle
authors.affiliation: Biology Department, De La Salle University, Taft Avenue, Manila, 0922, Philippines.
authors.forename: Esperanza C
authors.initials: EC
authors.lastname: Cabrera
authors.affiliation: Institute of Biology and Natural Science Research Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines.
authors.forename: Juliana Janet M
authors.initials: JJ
authors.lastname: Puzon
authors.affiliation: Institute of Biology and Natural Science Research Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines.
authors.forename: Windell L
authors.initials: WL
authors.lastname: Rivera
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002245:Carbon Dioxide / Q000737:chemistry; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002648:Child; D025924:Chromatography, Supercritical Fluid; D024901:Drug Resistance, Multiple, Bacterial; D000431:Ethanol / Q000737:chemistry; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000382:microbiology; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D008297:Male; D000432:Methanol / Q000737:chemistry; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D031721:Piper betle / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry; D065507:Vancomycin-Resistant Enterococci / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D012997:Solvents; D002245:Carbon Dioxide; D000431:Ethanol; D000432:Methanol