مهار استرپتولیزین O توسط آلیسین- یک ترکیب فعال موجود در سیر

Title

Inhibition of Streptolysin O by allicin, an active component of garlic

English Abstract

Streptolysin O (SLO) is a potent cytolytic toxin produced by almost all strains of group A streptococci and considered important virulence factor for this organism. In this study we investigated the effect of allicin and aqueous garlic extract on haemolytic activity of SLO. All tested materials potentially inhibited the SLO haemolytic activity. Allicin neutralizes SLO in a dose- and time-dependent manner. Fifteen minute incubation of SLO with 35 µg concentration of allicin, totally inhibited haemolytic activity of SLO (IC50 = 5.97 µg). The inhibitory activity of old extract of garlic was equipotent as pure allicin (IC50 = 6.27 µg; p < 0.05). In contrast fresh extract of garlic inhibits the SLO haemolytic activity at lower concentrations (IC50 = 1.59 µl; 1.9 µg allicin). The inhibitory effect of the allicin was restored by addition of reducing agent DTT at 2 mM, suggesting that allicin likely inhibits the SLO by binding to cysteinyl residue in the binding site. These results indicate a new activity for allicin and may be proposed as an alternative drug against streptococcal diseases.

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