Glutathione Reductase (GR) Assay Kit

Glutathione reductase (GR) is a pivotal flavoenzyme essential for maintaining cellular redox homeostasis. It is abundantly expressed in tissues with high metabolic activity, such as the liver and brain. GR specifically catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG) to its reduced form (GSH), thereby sustaining intracellular GSH pools. As a master antioxidant, GSH directly scavenges reactive oxygen species and serves as a co-substrate for glutathione peroxidase (GPx), underpinning critical processes including detoxification, DNA synthesis, and immune regulation. GR activity quantification is critical for evaluating oxidative stress-related disorders, drug development, and toxicological assessments.

This kit can detect GR activity in samples such as cells, tissue homogenates, or erythrocytes by colorimetric method. The detection principle is based on the cascade reaction of GR catalyzing the reduction of GSSG to GSH: GR first uses NADPH to reduce GSSG to GSH, and then the newly generated GSH reacts with the substrate DTNB to form yellow TNB and GSSG. When GSSG/GSH was excessive in the reaction system and GR activity became the rate-limiting step, the formation rate of TNB is positively correlated with GR activity. GR enzyme activity changes can be evaluated by detecting the absorbance changes of TNB at 412 nm.

Figure 1. Glutathione reductase measured in liver samples