Oxidative stress induced by cadmium in the plasma, erythrocytes and lymphocytes of rats: Attenuation by grape seed proanthocyanidins
Authors: V Manoharan
B Nazima
S Miltonprabu
Journal: Human & Experimental Toxicology (2016)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Cadmium; ROS; erythrocytes; grape seed proanthocyanidin; oxidative stress
Affiliations: Department of Zoology, Faculty of Science, Annamalai University, Chidambaram, Tamil Nadu, India., Department of Zoology, Faculty of Science, Annamalai University, Chidambaram, Tamil Nadu, India .

Abstract:  The present study has been designed to investigate the ameliorative effect of grape seed proanthocyanidins (GSP) on cadmium (Cd)-induced oxidative damage in rat erythrocytes. Twenty four male Wistar rats were divided into four groups: control, GSP-treated group (100 mg kg(-1) body weight (BW)), Cd-treated group (cadmium chloride, 5 mg kg(-1) BW), and GSP + Cd-treated group in which GSP was orally pre-administered 90 min before Cd intoxication for 4 weeks. At the end of the experimental period, blood samples were collected by cardiac puncture and were processed for various biochemical estimations. The extent of oxidative damage in isolated rat erythrocyte membrane was assessed by measuring lipid peroxidation, enzymatic and non-enzymatic content, calcium ion (Ca(2+))/magnesium ion (Mg(2+))-ATPase and sodium ion (Na(+))/potassium ion (K(+))-ATPase activities, free iron, calcium, hydrogen peroxide (H2O2) concentration, and osmotic fragility. Our results unveiled that Cd intoxication significantly increased the erythrocyte lipid peroxidation markers and decreased the activity of enzymatic and non-enzymatic markers in erythrocytes. Conversely, GSP pretreatment significantly prevented the decrease in the activities of antioxidant enzymes and membrane-bound ATPases. GSP also restored the levels of iron, calcium, and H2O2 in Cd-treated rats. Conformational changes in erythrocytes of various groups were also determined using morphological and ultrastructural electron microscopic analysis. The findings of our study clearly revealed that GSP affords superior protection against Cd-induced reactive oxygen species generation, lipid peroxidation, and free radical generation in Cd-treated rats, which presumably reflects the ability of this flavonoid to protect erythrocytes and lymphocytes of rats from the toxic effects of Cd. 

Retracted: No

PubPeer comments:
 ![file] , 
 ![file] , 
 The interaction for endogenous RIG-I and ZNF598 is almost undetectable, even after poly(I:C) stimulation ![file] , 
 Thank you for reading our manuscript. #1 is a comment comparing Fig 3A and Supplemental Figure S2E blots. Since Supplemental Figure S2E is an experiment of a reporter gene assay and Fig 3A is an experiment of the immunoprecipiation assay to detect the ubiquitination of RIG-I, there are differences in their methods. #1 comment is an issue related to the expression levels of exogenously expressed ZNF598 and the exposure time of western blotting. Exposure time of western blotting is adjusted to avoid the saturation of overexpressed ZNF598, and thus the endogenous ZNF598 bands were faint in those experimental conditions. In #2 comment, Fig 3B and Fig 2I are compared. In Fig 2I, we generated ZNF598 KO HeLa cells using CRISPR-Cas9 system. We isolated several KO clones and found that ZNF598 KO hardly affected the RIG-I protein levels. The issue seems to be related to a variability of the western blotting data. It is well known that there are several technical difficulties to detect the physical interaction between endogenous proteins, such as the antibody titers and the ability to precipitate the antigen. #3 comment is related to those the technical difficulties, but we confirmed that ZNF598 bound to RIG-I as described in our paper. ,