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.

Screening Antibacterial Effects of Vietnamese Plant Extracts Against Pathogens Caused Acute Hepatopancreatic Necrosis Disease in Shrimps

“…We observed that four of five examined plants, including P. guajava, P. amanus, P. betel, and R. tomentosa, showed antibacterial activities at different levels. These results were similar to previous studies that reported these plants' effects on bacteria [31][32][33][34][35][36][37] and further give evidence to explain their Vietnamese ethnic applications in bacterial diseases [12,13]. In addition, our results demonstrated that among all tested plants, P. amanus and R. tomentosa had outstanding effects on AHPND-caused bacteria, as they always represented the strongest activities, regardless of applied investigation methods (agar disc diffusion or broth dilution) and also regardless of tested strains (V. parahaemolyticus …”

Chemical Composition, Toxicity and Antifungal Activities of Megaphrynium macrostachyum (K. Schum) Leaf Extract against Foodborne Fungi

“…1 filter paper) and the methods used were based on methods adopted by Adekunle and Ikumapayi (2006) and Valle et al (2016).…”

Attenuation of Adhesion, Biofilm Formation and Quorum Sensing ofCampylobacter jejunibyEuodia ruticarpa

“…One of the promising ways to reduce health hazards and economic losses due to the food-borne microorganisms is the use of natural and organic antimicrobials, such as natural plant compounds (Sirsat et al, 2009). In particular, ethanol solution extracts of different plants have been proposed to control food pathogens (Serio et al, 2014) and multidrug resistant bacteria (Valle et al, 2016). Euodia ruticarpa (A.…”