Evaluation of antioxidant activity of NG-R1 saponin against bacterial cells in induced oxidative stress - a preliminary study.

Abstract

Notoginsenoside R1 (NG-R1) is isolated from Panax notoginseng, a medicinal herb well-known for its long use in traditional Chinese medicine. NG-R1 is relatively under-studied in research on bacteria. The aim of the study was to investigate antioxidant properties of NG-R1 saponin of selected bacterial strains of intestinal microbiota that may be involved in the pathogenesis of thromboembolic diseases. Enterococcus faecalis and Escherichia coli were used in the study. The study determined the concentration of hydroperoxides, the level of lipid peroxidation, as well as carbonyl groups and free thiol groups. The research carried out in this way will allow determination of the influence of the above factors on bacteria living in intestinal microbiota. An evaluation of selected parameters of oxidative stress allowed to check whether the tested compound could reduce the pro-thrombotic activity of bacteria that were stimulated with H2O2. It was found that NG-R1 reduced hydroperoxide levels in both types of bacteria. In turn, lipid peroxidation initiated by H2O2 was suppressed by NG-R1. Hydrogen peroxide led to a strong increase in the level of carbonyl groups in Enterococcus faecalis and, to a lesser extent, in Escherichia coli. The addition of NG-R1 to the medium significantly reduced the level of carbonyls. Additionally, NG-R1 also induced a significant increase in the level of free thiol groups. Obtained results indicate that NG-R1 may have a protective effect on the intestinal microbiom through mechanisms involving changes in the redox state.