Enhancing Antibiotics Efficacy by Combination of Kuraridin and Epicatechin Gallate with Antimicrobials against Methicillin-Resistant <i>Staphylococcus aureus</i>

oleh: Ben Chung-Lap Chan, Nilakshi Barua, Clara Bik-San Lau, Ping-Chung Leung, Kwok-Pui Fung, Margaret Ip

Format: Article
Diterbitkan: MDPI AG 2023-01-01

Deskripsi

Background: <i>Staphylococcus aureus</i> is an opportunistic pathogen and a major cause of nosocomial and community-acquired infections. The alarming rise in Methicillin-resistant <i>S. aureus</i> (MRSA) infection worldwide and the emergence of vancomycin-resistant MRSA strains have created an urgent need to identify new and alternative treatment options. Triple combinations of antimicrobials with different antimicrobial mechanisms may be a good choice to overcome antimicrobial resistance. Methods: In this study, we combine two natural compounds: kuraridin from <i>Sophora flavescens</i> and epicatechin gallate (ECG) from <i>Camellia sinensis</i> (Green tea), which could provide the best synergy with antibiotics against a selected panel of laboratory MRSA with known resistant mechanisms and clinical community-associated (CA) and hospital-associated (HA) MRSA as well. Results: The combined use of ECG and kuraridin was efficacious in inhibiting the growth of a panel of tested MRSA strains. The antibacterial activities of gentamicin, fusidic acid and vancomycin could be further enhanced by the addition of ECG and kuraridin. In time-kill study, when vancomycin (0.5 μg/mL) was combined with ECG (2 μg/mL) and kuraridin (2 μg/mL), a very strong bactericidal growth inhibition against 3 tested strains ATCC25923, MRSA ST30 and ST239 was observed from 2 to 24 h. ECG and kuraridin both possess anti-inflammatory activities in bacterial toxin-stimulated peripheral blood mononuclear cells by suppressing the production of inflammatory cytokines (IL-1β, IL-6 and TNFα) and are non-cytotoxic. In a murine pneumonia model infected with ATCC25923, MRSA ST30 or ST239, the combined use of ECG and kuraridin with vancomycin could significantly reduce bacterial counts. Conclusions: The present findings reveal the potential of ECG and kuraridin combination as a non-toxic herbal and antibiotics combination for MRSA treatment with antibacterial and anti-inflammatory activities.