Antibacterial Activity of Epigallocatechin Gallate (EGCG) against Shigella flexneri

Abstract

Shigella flexneri (S. flexneri), a major intestinal pathogen, is a global public health concern. The biofilms formed by S. flexneri threaten environmental safety, since they could promote the danger of environmental contamination and strengthen the disease-causing properties of bacteria. Epigallocatechin gallate (EGCG) is an important catechin in tea, which has a high antibacterial activity. However, its antibacterial mechanism is still unclear. This research aims to quantify the antibacterial function and investigate the possible mechanism of EGCG inhibition of S. flexneri. The minimum inhibitory concentration (MIC) of EGCG against planktonic S. flexneri in the investigation was measured to be 400 μg/mL. Besides, SDS-PAGE and field emission scanning electron microscopy showed that EGCG interfered with protein synthesis and changed bacteria morphology. Through controlling the expression of the mdoH gene, EGCG was found to be able to prevent an S. flexneri biofilm extracellular polysaccharide from forming, according to experiments utilizing the real-time PCR test. Additional research revealed that EGCG might stimulate the response of S. flexneri to oxidative stress and prevent bacterial growth. These findings suggest that EGCG, a natural compound, may play a substantial role in S. flexneri growth inhibition.

Antimicrobial resistance and mechanisms of epigenetic regulation

“…Zhang et al. found that EGCG prevented Shigella flexneri biofilm extracellular polysaccharide from forming through reducing the expression of mdoH gene ( Zhang et al., 2023 ). These findings suggest that epigenetic drugs have the potential to be used as a treatment for patients with multidrug-resistant bacterial infections.…”

“…With the deepening of research, Serra et al thought that EGCG directly interfered with the assembly of curli fimbriae into amyloid fibrils and reduced the synthesis of CsgD (activator of curli fimbriae and cellulose biosynthesis) by promoting the expression of RybB ncRNA, ultimately inhibited the formation of cell membranes and affected biofilm-mediated antibiotic resistance and host defense (Serra et al, 2016) As well as, EGCG was found to be a suitable natural drug targeting LuxS/AI-2 system of H. pylori by high-throughput screening and molecular dynamics simulation (Ashok et al, 2023). Zhang et al found that EGCG prevented Shigella flexneri biofilm extracellular polysaccharide from forming through reducing the expression of mdoH gene (Zhang et al, 2023). These findings suggest that epigenetic drugs have the potential to be used as a treatment for patients with multidrugresistant bacterial infections.…”

Plant‐derived virulence arresting drugs as novel antimicrobial agents: Discovery, perspective, and challenges in clinical use

“…qRT-PCR data revealed a significant down-regulation in the transcription level of a biofilm-related gene called mdoH. Inhibition of the gene expression of mdoH may contribute to a lower level of polysaccharide synthesis and thus disturb the biofilm formation in S. flexneri (Zhang et al, 2023). EGCG also could be a potential QSI against P. aeruginosa infection due to it significantly down-regulated the expression of QS-regulatory genes, inhibited the biofilm formation, and reduced the production of VFs in a dose-dependent manner.…”

Structural Modification of Epigallocatechin-3-gallate to (2R,3R)-5,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)chroman-3-yl l-valinate in Four Steps

“…Unlike green tea, black tea involves a fermentation process in its preparation, during which these phenolic compounds are oxidized to form new compounds, such as theobromine and theaflavin, thereby diminishing the EGCG content in black tea. EGCG exhibits a broad spectrum of biological activities, including hypoglycemic [1], antibacterial [2], antiviral [3], antioxidant [4], anti-atherosclerotic [5], antitumor [6] and anti-inflammatory [7] effects. Therefore, tea and its extract have been widely commercialized, commonly in the pharmaceutical, healthcare, and food industries [8][9][10].…”