Ginsenoside Rg3 promotes inflammation resolution through M2 macrophage polarization

Background: Ginsenosides have been reported to have many health benefits, including anti-inflammatory effects, and the resolution of inflammation is now considered to be an active process driven by M2-type macrophages. In order to determine whether ginsenosides modulate macrophage phenotypes to reduce inflammation, 11 ginsenosides were studied with respect to macrophage polarization and the resolution of inflammation. Methods: Mouse peritoneal macrophages were polarized into M1 or M2 phenotypes. Reverse transcription-polymerase chain reaction, Western blotting, and measurement of nitric oxide (NO) and prostaglandin E2 levels were performed in vitro and in a zymosan-induced peritonitis C57BL/6 mouse model. Results: Ginsenoside Rg3 was identified as a proresolving ginseng compound based on the induction of M2 macrophage polarization. Ginsenoside Rg3 not only induced the expression of arginase-1 (a representative M2 marker gene), but also suppressed M1 marker genes, such as inducible NO synthase, and NO levels. The proresolving activity of ginsenoside Rg3 was also observed in vivo in a zymosan-induced peritonitis model. Ginsenoside Rg3 accelerated the resolution process when administered at peak inflammatory response into the peritoneal cavity. Conclusion: These results suggest that ginsenoside Rg3 induces the M2 polarization of macrophages and accelerates the resolution of inflammation. This finding opens a new avenue in ginseng pharmacology

Electronic Effect in Methanol Dehydrogenation on Pt Surfaces: Potential Control during Methanol Electrooxidation

Establishing a relationship between the catalytic activity and electronic structure of a transition-metal surface is important in the prediction and design of a new catalyst in fuel cell technology. Herein, we introduce a novel approach for identifying the methanol oxidation reactions, especially focusing on the effect of the Pt electronic structure on methanol dehydrogenation. By systematically controlling the electrode potential, we simplified the reaction paths, excluding other unfavorable effects, and thereby obtained only the methanol dehydrogenation activity in terms of the electronic structure of the Pt surface. We observed that the methanol dehydrogenation activity of Pt decreases when the position of the d-band center relative to the Fermi level is lower, and this fundamental relation provides advanced insight into the design of an optimal catalyst as the anode for direct methanol fuel cells