Effects of some antibiotics on human erythrocyte glutathione reductase: anin vitrostudy

Abstract

Inhibitory effects of some antibiotics on purified human erythrocyte glutathione reductase were investigated. Human erythrocyte glutathione reductase was purified 2800-fold (29% yield) at 48C using 2 0 , 5 0 -ADP Sepharose 4B affinity gel and Sephadex G-200 gel filtration chromatography. SDS polyacrylamide gel electrophoresis showed a single band for the enzyme. Imipenem, rifamycin, sulfanylacetamide, ceftazidime, chloramphenicol, seftriaxon, vancomycin, cefuroxime and ornidazole exhibited inhibitory effects but clindamycin, lincomycin, amoxicillin, amikacin exhibited activatory effects on the enzyme in vitro. The IC 50 values of imipenem, rifamycin, sulfanylacetamide, ceftazidime, chloramphenicol, seftriaxon, vancomycin, cefuroxime and ornidazole were 0.030, 0.146, 0.59, 2.476, 2.36, 2.88, 4.83, 15.43 and 19.632 mM, respectively, and the K i constants were 0.06^0.01, 0.275^0.10, 0.85^0. 05, 3.59^0.51, 3.85^0.40, 3.71^0.60, 15.11^2.50, 23.50^2.94 and 28.49^6.50 mM, respectively. While imipenem, rifamycin, sulfanylacetamide, ceftazidime, chloramphenicol and seftriaxon cefuroxime and ornidazole showed competitive inhibition, vankomycine displayed noncompetitive inhibition.

Effects of some analgesic anaesthetic drugs on human erythrocyte glutathione reductase: anin vitrostudy

“…The resultant solution was clear, and contained partially purified enzyme. Then it dialysed at 48C in 1 mM EDTA þ 10 mM K-phosphate buffer (pH 7.5) for 2 h with two changes of buffer [16]. Partially purified enzyme solution was kept at 48C.…”

“…Active fractions were collected and dialyzed with equilibration buffer. All of the procedures were performed at 48C [16].…”

“…The packed red cells were washed three times with KCl (0.16 M) and hemolyzed with 5 volume of ice-cold water and then centrifuged (48C, 10,000 £ g, for 30 min) to remove the ghosts and intact cells [16].…”

“…In each fraction, enzyme activity was determined at 340 nm. Active fractions were collected and stored at 2 208C for testing the enzyme purity by electrophoresis [16].…”

Susceptibility of cord blood antioxidant enzymes glutathione reductase, glutathione peroxidase and glutathione S-transferase to different antibiotics:in vitroapproach

“…Some studies found either increases or decreases in mammalian enzyme activities, and the inhibitor or activator effects of some antibiotics have been rarely investigated. Nevertheless, a few recent investigations regarding the inhibitory actions of different type of drugs and chemicals on GR have been reported by our group [9][10][11][12][13][14][15] . Cefuroxime is a second-generation cephalosporin antibiotic whereas ceftriaxone, ceftizoxime and cefoperazone are third-generation cephalosporin antibiotics.…”