Inhibitory effect of catechin against the superantigen staphylococcal enterotoxin B (SEB)

Abstract

Staphylococcal superantigens (SsAgs) have gained attention as one of the factors aggravating atopic dermatitis (AD) and several potential mechanisms of AD aggravation by SsAgs have been reported. Tea catechin has been found to have many unique antimicrobiological activities such as antibacterial, antiviral, antifungal and antitoxic effects. In the present study, we investigated the inhibitory effect of the green tea catechin extract, Polyphenon, and (-)-epigallocatechin gallate (EGCg) on staphylococcal enterotoxin B (SEB) and its mechanisms of action, and we also discuss the possibility of therapeutic benefits for AD patients of tea catechin. Polyphenon inhibited the lethal toxicity of SEB and the SEB-induced production of TNF-alpha, IFN-gamma and IL-4 following its intraperitoneal administration to BALB/c mice. Although Polyphenon is composed of several isomers among which EGCg is approximately 50% of the total, we considered that most of the inhibitory effect of Polyphenon in mice could be attributed to EGCg. EGCg was immediately bound to SEB molecules and neutralized SEB in a dose- and incubation time-dependent manner without molecular weight alteration of the SEB molecule. Furthermore, EGCg inhibited SEB-induced TNF-alpha and IFN- gamma production and IL-2, IFN-gamma, IL-10 and IL-12 p40 mRNA expression in human PBMCs from normal donors in a dose-dependent manner. Inhibition of SsAg-induced T-cell activation by catechin was observed in both in vivo and in vitro studies, suggesting that catechin may be useful in the treatment of AD.

Inhibition of Bacterial Toxin Activity by the Nuclear Stain, DRAQ5™

“…Some of these molecules act by precipitating the targeted toxin from solution (Choi et al , 2007; Hisano et al , 2003; Verhelst et al , 2013). We found that Draq5 inhibits toxin activity by directly modifying membrane structure, a finding that is similar to a previously reported finding that resveratrol inhibits cholera toxin (CT) activity by disrupting internalization of the toxin but not binding to the cell membrane (Morinaga et al , 2010).…”

Green tea extracts attenuate doxorubicin-induced spermatogenic disorders in conjunction with higher telomerase activity in mice

“…Although there have been a number of studies on the antitoxic effects of catechins [31][32][33][34][35], only a few studies of Fig. 2 Final body weight of mice.…”

Anti‐infective properties of epigallocatechin‐3‐gallate (EGCG), a component of green tea

“…In experiments using Bagg albino (BALB/c) mice and human PBMCs another interesting antibacterial effect of EGCG was demonstrated, polyphenon, consisting of 50% EGCG, neutralized staphylococcal enterotoxin B in a dose- and incubation time-dependent manner by binding to enterotoxin B molecules (Hisano et al, 2003). Further work is needed to determine the effects of EGCG against different enterotoxins, and whether EGCG has neutralization properties against other staphylococcal superantigens such as toxic shock syndrome toxin.…”