Interactions of Tea-Derived Catechin Gallates with Bacterial Pathogens

Abstract

Green tea-derived galloylated catechins have weak direct antibacterial activity against both Gram-positive and Gram-negative bacterial pathogens and are able to phenotypically transform, at moderate concentrations, methicillin-resistant Staphylococcus aureus (MRSA) clonal pathogens from full β-lactam resistance (minimum inhibitory concentration 256–512 mg/L) to complete susceptibility (~1 mg/L). Reversible conversion to susceptibility follows intercalation of these compounds into the bacterial cytoplasmic membrane, eliciting dispersal of the proteins associated with continued cell wall peptidoglycan synthesis in the presence of β-lactam antibiotics. The molecules penetrate deep within the hydrophobic core of the lipid palisade to force a reconfiguration of cytoplasmic membrane architecture. The catechin gallate-induced staphylococcal phenotype is complex, reflecting perturbation of an essential bacterial organelle, and includes prevention and inhibition of biofilm formation, disruption of secretion of virulence-related proteins, dissipation of halotolerance, cell wall thickening and cell aggregation and poor separation of daughter cells during cell division. These features are associated with the reduction of capacity of potential pathogens to cause lethal, difficult-to-treat infections and could, in combination with β-lactam agents that have lost therapeutic efficacy due to the emergence of antibiotic resistance, form the basis of a new approach to the treatment of staphylococcal infections.

Effect-Directed Profiling of 17 Different Fortified Plant Extracts by High-Performance Thin-Layer Chromatography Combined with Six Planar Assays and High-Resolution Mass Spectrometry

“…As for the observed antibacterial activity of Eschscholzia ( 18 ), its alkaloids have demonstrated antifungal [ 19 ] and some even antibacterial potential [ 20 , 21 ]. In accordance with our findings is also the well documented antibacterial activity of green tea [ 22 , 23 ] and grape pomace [ 24 ]. Extracts and essential oils of lemon balm [ 25 ] and rosemary [ 26 ] have also proven antibacterial activity, which confirms our results.…”

“…Catechins in green tea and meadowsweet were therefore in part responsible for the activities of both plants. The antibacterial activity of green tea is ascribed in particular to galloylated catechins such as (−)-epicatechin gallate and (−)-epigallocatechin gallate [ 6 , 22 , 23 ].…”

Antioxidant Properties of Lyophilized Rosemary and Sage Extracts and its Effect to Prevent Lipid Oxidation in Poultry Pátê

“…Additionally, the high concentration of catechin in the rosemary extract may be responsible for the strong inhibitory action against all the pathogenic bacteria tested in this study. In fact, catechin and epigolocatechin gallate from teas were able to inhibit and kill some Gram-positive and Gram-negative bacterial species [19]. Though the ethanolic extract of sage did not inhibit the Staphylococcus aureus at the concentrations tested in this study (MIC > 5 mg/mL), it did inhibit the bacteria Samonella enteritidis and Bacillus cereus at higher concentrations of 0.63 mg/mL and 1.25 mg/mL, respectively.…”

Green Tea-Derived Epigallocatechin Gallate Inhibits Acid Production and Promotes the Aggregation of <b><i>Streptococcus mutans</i></b> and Non-Mutans Streptococci

“…Green tea infusions and green tea extract-based beverages are the main sources of EGCG intake in daily life. Green tea-derived catechins (tea-derived polyphenols) account for 10-15% of the weight of dried green tea leaves, and EGCG accounts for 50-70% of total catechins in green tea [Yang et al, 2009;Khan and Mukhtar, 2018;Taylor, 2020]. More than 1 mg/mL EGCG can be released into green tea infusions, which is considered to be safe [Liu et al, 2014;Dekant et al, 2017;Koch et al, 2018].…”