Mouse Gpx2 (Glutathione peroxidase 2) ELISA Kit

A large body of evidence highlights that propolis exerts many biological functions that can be ascribed to its antioxidant and anti-inflammatory components, including different polyphenol classes. Nevertheless, the molecular mechanisms are yet unknown. The aim of this study is to investigate the mechanisms at the basis of propolis anti-inflammatory and antioxidant activities. The effects of two brown and green propolis extractschemically characterized by RP-HPLC-PDA-ESI-MSnon the expression levels of miRNAs associated with inflammatory responses (miR-19a-3p and miR-203a-3p) and oxidative stress (miR-27a-3p and miR-17-3p), were determined in human keratinocyte HaCat cell lines, treated with non-cytotoxic concentrations. The results showed that brown propolis, whose major polyphenolic components are flavonoids, induced changes in the expression levels of all miRNAs, and was more active than green propolis (whose main polyphenolic components are hydroxycinnamic acid derivatives) which caused changes only in the expression levels of miR-19a-3p and miR-27a-3p. In addition, only brown propolis was able to modify (1) the expression levels of mRNAs, the target of the reported miRNAs, which code for Tumor Necrosis Factor-alpha (TNF-alpha), Nuclear Factor, Erythroid 2 Like 2 (NFE2L2) and Glutathione Peroxidase 2 (GPX2), and (2) the protein levels of TNF-alpha and NFE2L2. In conclusion, brown and green propolis, which showed different metabolite profiles, exert their biological functions through different mechanisms of action.

Menadione (MD), a simplest synthetic quinone used with reactive oxygen species (ROSs) generating agents, causes damages to Saccharomyces cerevisiae KNU5377. To understand antioxidant defense mechanisms under adaptive stress response, we have performed biochemical analyses and the genome-wide gene expression analysis after exposure to 120 mu M of MD with and without adaptation. KNU5377 could survive at higher concentration of MD, 680 mu M for I h, comparing with S. cerevisiae W303, ATCC24858 as reference strains. Glutathione peroxidase (GPX2), thioredoxin peroxidase 2 (TSA2), and thioredoxin reductase (TRR2) were up-regulated over 10-fold after treatment of 120 mu M. Superoxide dismutase (SOD1), catalase (CTA1), glucose-6-phosphate dehydrogenase (ZWF1), glutathione peroxidase (GPX2, HYR1), glutathione reductase (GLR1), thioredoxin peroxidase (AHPI), and thioredoxin 2 (TRX2) were also strongly induced after adaptation. Additionally, transcriptional analysis of those genes was well corresponded with up-regulated protein expression and enzyme activity. Antioxidant defense mechanisms containing SOD1, ZWF and TRX2 maybe orchestrate by the different levels at the same time and function to produce effective defense systems. These results suggest that specific mechanisms including the three proteins were well organized for acquiring adaptive response to MD in this strain. (c) 2006 Elsevier Ltd. All rights reserved.