Antimicrobial properties of green tea catechins

Abstract

Extracts of leaves from the tea plant Camellia sinensis contain polyphenolic components with activity against a wide spectrum of microbes. Studies conducted over the last 20 years have shown that the green tea polyphenolic catechins, in particular (-)-epigallocatechin gallate (EGCg) and (-)-epicatechin gallate (ECg), can inhibit the growth of a wide range of Gram-positive and Gram-negative bacterial species with moderate potency. Evidence is emerging that these molecules may be useful in the control of common oral infections, such as dental caries and periodontal disease. Sub-inhibitory concentrations of EGCg and ECg can suppress the expression of bacterial virulence factors and can reverse the resistance of the opportunistic pathogen Staphylococcus aureus to beta-lactam antibiotics. For example, relatively low concentrations of ECg can sensitize methicillin-resistant S. aureus (MRSA) clinical isolates to levels of oxacillin that can be readily achieved in clinical practice. Catechin gallates such as ECg intercalate into phopsholipid bilayers and it is likely that they affect both virulence and antibiotic resistance by perturbing the function of key processes associated with the bacterial cytoplasmic membrane.

Evaluation of the pH and titratable acidity of teas commercially available in Brazilian market

“…The literature has reported many different properties of this tea against dental caries due to presence of their catechins [32][33] . Furthermore, green tea has components which can inhibit matrix metalloproteinase that are present on saliva and on mineralized dental tissues 34 decreasing the dental erosion/ abrasion in situ 35 .…”

Inhibitory Effects of Commercial and Enriched Green Tea Extracts on the Growth of Brochothrix thermosphacta, Pseudomonas putida and Escherichia coli

“…Furthermore, other authors have found that the broth assay were more efficient than agar assays for a large number of antibiotics (Baker, Stocker, Culver, & Thornsberry, 1991). According to Hara (2001), the EGC, EGCG and ECG catechins seem to be the most potent antibacterial agents and the activity of catechins alone is reported to be modest (Taylor, Hamilton-Miller, & Stapleton, 2005). Hence, the observed results may be considered as a synergistic effect between the different compounds found in green tea.…”

Inhibición de la expresión del sistema agr de Staphylococcus aureus resistente a meticilina mediante el uso de polifenoles totales de hojas de aguacate mexicano (Persea americana var. drymifolia)

“…drymifolia), así como su perfil fitoquímico funcional. (Motamedi et al, 2014;Bezerra dos Santos et al, 2015, Taylor et al, 2005. La actividad bactericida puede deberse en parte a la presencia de saponinas; estos compuestos tienen la capacidad de romper las membranas de los microorganismos modificando la tensión superficial del medio extracelular (Nassiri y Hosseinzadeh, 2008).…”