Effects of some analgesic anaesthetic drugs on human erythrocyte glutathione reductase: an in vitro study

Inhibitory effects of some analgesic and anaesthetic drugs on human erythrocyte glutathione reductase were investigated. For this purpose, human erythrocyte glutathione reductase was initially purified 2139-fold in a yield of 29% by using 2', 5'-ADP Sepharose 4B affinity gel and Sephadex G-200 gel filtration chromatography. SDS polyacrylamide gel electrophoresis confirmed the purity of the enzyme by sharing a single band. A constant temperature (+4C) was maintained during the purification process. Diclofenac sodium, ketoprofen, lornoxicam, tenoxicam, etomidate, morphine and propofol exhibited inhibitory effects on the enzyme in vitro using the Beutler assay method. Ki constants and IC50 values for drugs were determined from Lineweaver-Burk graphs and plotting activity % versus [I] graphs, respectively. The IC50 values of diclofenac sodium, ketoprofen, lornoxicam, propofol, tenoxicam, etomidate and morphine were 7.265, 6.278, 0.3, 0.242, 0.082, 0.0523 and 0.0128mM and the Ki constants were 23.972.1, 22.147.6, 0.420.18, 0.4180.056, 0.130.025, 0.07250.0029 and 0.01650.0013mM, respectively. While diclofenac sodium, ketoprofen, lornoxicam, tenoxicam etomidate and morphine showed competitive inhibition, propofol displayed noncompetitive inhibition.