TITLE:
Epigallocatechin Gallate-Stearate Enhances the Efficacy of Antibiotics
AUTHORS:
Ayuni Yussof, Umme Habiba, Deborah Liaw, Tinchun Chu, Lee H. Lee
KEYWORDS:
EGCG, EGCG-Stearate, Antibiotic Resistance, Disk Diffusion Methods
JOURNAL NAME:
Open Journal of Medical Microbiology,
Vol.9 No.3,
August
30,
2019
ABSTRACT: Introduction: The rise in antibiotic resistant cases has caused a global concern. Researchers around the world are trying to find a novel alternative to combat this issue. Green tea with its many health benefits, including antibacterial and antiviral activity, has shown to be one of the most promising candidates to be used as an agent to solve this problem. Objective: This study focuses on evaluating the synergistic effects of antibiotics and two green tea polyphenols: epigallocatechin gallate (EGCG), and its modified lipophilic form epigallocatechin gallate stearate (EGCG-S). Methods: In this study, twelve antibiotics and eight bacteria: Gram-positive Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis) and Bacillus megaterium (B. megaterium); Gram-negative Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Serratia marcescens (S. marcescens), and Enterobacter aerogenes (E. aerogenes); and acid-fast Mycobacterium smegmatis (M. smegmatis) were used. Antibacterial synergism profiling of EGCG, EGCG-S and antibiotics has been established using a disk diffusion assay. Results: The results revealed that both 1% of EGCG and 1% EGCG-S enhanced the antimicrobial activities on antibiotics in various bacteria. Antimicrobial susceptibility study indicated that EGCG-S was able to enhance some antibiotics from the resistant category to intermediate or susceptible and/or from intermediate category to susceptible. Both EGCG and EGCG-S worked comparably on Gram-positive bacteria; in S. aureus, both compounds enhanced 5 antibiotics (AM10, CF30, C30, S10 and TE30) activities while EGCG-S had higher efficiency. B. megaterium were susceptible to most of the antibiotic treatment, thus the impact of EGCG and EGCG-S was insignificant. EGCG-S worked better than EGCG on Gram-negative bacteria; converted 9 antibiotics susceptibility in E. coli and P. aeruginosa, and 8 antibiotics in E. aerogenes. EGCG and EGCG-S also showed synergism on acid-fast bacteria M. smegmatis with EGCG-S has much higher efficiency than EGCG. Conclusion: The results suggested that EGCG-S might be a promising antibacterial synergistic agent with antibiotics to combat antibiotic-resistant bacteria.