Is it true that plant-derived polyphenols are always beneficial for the human? In vitro study on Leonurus cardiaca extract properties in the context of the pathogenesis of Staphylococcus aureus infections.

Is it true that plant-derived polyphenols are always beneficial for the human? In vitro study on Leonurus cardiaca extract properties in the context of the pathogenesis of Staphylococcus aureus infections. J Med Microbiol. 2016 Aug 8; Authors: Micota B, Sadowska B, Podsedek A, Paszkiewicz M, Sosnowska D, Rozalska B Abstract The aim of the study was to determine whether Leonurus cardiaca L. herb extract (LCE) used at subinhibitory concentration modifies the characteristics of S. aureus, important in the pathogenesis of invasive infections originating from the bloodstream, in a way favorable for the human host. Polyphenol rich LCE, a common ingredient in the pharmaceutical products used for various cardiovascular and nervous system disorders, had shown interesting antibacterial and anti-biofilm properties in our previous studies. Our current findings indicate that the following S. aureus characteristics were decreased, depending on the LCE concentration: i) formation of aggregates in plasma, ii) adherence to a fibrin coated surface, iii) staphylocoagulase-dependent plasma clotting, iv) bacterial survival in whole human blood in an ex vivo model, v) expression of cell surface protein A (SpA), vi) synthesis of -toxin. However, staphylococcal tolerance to exogenous hydrogen peroxide was enhanced after pre-incubation with LCE, possibly due to the increased activity of bacterial antioxidant enzymes: a possibility confirmed by the higher pro...
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research