A study on the effects of inhibition mechanism of curcumin, quercetin, and resveratrol on human glutathione reductase through in vitro and in silico approaches

Abstract

Glutathione reductase (GR) is a major antioxidant enzyme essential to maintain GSH/GSSG ratio by catalyzing recovery of reduced glutathione (GSH) from oxidized glutathione (GSSG). Because of this vital task, the inhibition of GR is an important target in the treatment of many diseases, so we aimed to identify natural and new GR inhibitors to be guide for drug design.

For this purpose, two different approaches were used. The first one is in vitro inhibition, the first phase of which was the purification of the enzyme from human erythrocyte by 2’, 5’-ADP Sepharose 4B affinity chromatography, and then the in vitro inhibition effects of curcumin, quercetin, and resveratrol were examined. The second one is in silico study, which was performed to elucidate the drug-likeness, active site identification and inhibition mechanisms of these compounds.

hGR was isolated from human erythrocytes with 7.036 EU/mg protein specific activity and 48.97% yield. Then, IC₅₀ values were as 17.25 ± 3.8 µM, 57.8 ± 14.2 µM, and 520 ± 96.7 µM for curcumin, quercetin, and resveratrol respectively. Docking studies of compounds were performed against hGR receptors with induced-fit docking method. The compound showed Glide score as 10.519 kcal/mol, −9.789, and −8.133 respectively.

In conclusion, it was seen that curcumin is the much better inhibitor than quercetin and resveratrol for hGR according to both in vitro and in silico studies. Curcumin, a potential inhibitor of hGR, can be used in drug design to target the glutathione system in cellular injury.

Communicated by Ramaswamy H. Sarma

Keywords:

• Glutathione reductase
• inhibition
• phenolic compounds
• in silico study
• inducer fit docking

Human and animal rights

No humans or animals were used in this study. The human blood used in the examination is the waste blood supplied from Erzurum Turkish Red Crescent Blood Centre.

Acknowledgements

The authors are indebted to Dr. Halide Sedef Karaman for contribution to the docking study process of this article. The authors thank to Dr. Merve GEÇİKLİ from English Language Teaching Department of Atatürk University for language editing of manuscript.

Disclosure statement

The author(s) declared that they have no conflict of interest.

Additional information

Funding

This work was supported by a grant from the Scientific Research Project of Atatürk University of Turkey [Grant Number: FAD-2017-6107].