Pithecellobium clypearia extract enriched in gallic acid and luteolin has antibacterial activity against MRSA and reduces resistance to erythromycin, ceftriaxone sodium and levofloxacin

作者：C. Liu, Hui Huang, Qian Zhou, Bingqian Liu, Yang Wang, P. Li, Kang Liao, Weiwei Su · 发表于：Journal of Applied Microbiology · 年份：2020 · DOI：10.1111/jam.14668 · 被引用次数：20 · 研究领域：Bacterial biofilms and quorum sensing、Antimicrobial Resistance in Staphylococcus、Antimicrobial Peptides and Activities

Antibiotic adjuvants can give a second life to the antibiotics to which bacteria are highly resistant. We evaluated the antimicrobial effects of extracts from Pithecellobium clypearia against methicillin‐resistant Staphylococcus aureus (MRSA) and also the potential for synergy with several antibiotics. For this study, four extracts from P. clypearia were tested on MRSA using the broth microdilution method for activity assessment. The ethyl acetate fraction (S20b) had the strongest antibacterial activity against MRSA among the fractions tested. In all, 14 compounds such as gallic acid and luteolin in S20b were analysed by UFLC‐Q‐TOF‐MS/MS. S20b combined with erythromycin showed synergy effects against MRSA and combined with ceftriaxone sodium and levofloxacin showed additive effects against MRSA. Electron microscopy showed that extract S20b damaged the MRSA cell wall and K+ efflux measurements indicated that extract S20b increased cell membrane permeability. Moreover, S20b suppression of PBP2a expression was assessed by Western blot. Furthermore, an in vivo study was used to investigate the therapeutic potential of S20b based on a mouse pneumonia model. The in vitro study results have shown that S20b not only inhibits MRSA growth directly but also reduces the resistance of MRSA to the evaluated antibacterial agents. Based on the in vivo study, it can be concluded that S20b can treat pneumonia in the mouse model. This study is the first research to demonstrate that S20b can inh...