Induction of Oxidative Stress in Erythrocytes of Male Rats Subchronically Exposed to a Mixture of Eight Metals Found as Groundwater Contaminants in Different Parts of India

Abstract

Exposure of animals and humans to different metal components through contaminated drinking water can result in a wide range of adverse clinical conditions. Toxicological consequences arising from the concurrent repeated exposure to multiple metal contaminants are not known. The purpose of the present study was to evaluate the oxidative stress-inducing potential of a mixture of eight metals (arsenic, cadmium, lead, mercury, chromium, nickel, manganese, iron), representative of groundwater contamination in different areas of India, in erythrocytes of male rats subchronically exposed to environmentally relevant doses via drinking water. The selection of these metals, as determined by literature survey of groundwater contamination in India, was primarily based on the frequency of their occurrence and contamination level above World Health Organization maximum permissible limit (MPL) in drinking water. Male albino Wistar rats were exposed to the metal mixture at 0, 1, 10, and 100 times the mode concentrations (the most frequently occurring concentration) of the individual metals in drinking water for 90 days. In addition, one group of rats was also exposed to the mixture at a concentration equal to the MPL of individual components. The oxidative stress in erythrocytes was evaluated by assessing the magnitude of malondialdehyde production and reduced glutathione (GSH) content and the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione reductase (GR) after 30, 60, and 90 days of exposure. MPL and 1x dose levels did not cause any changes. The mixture at 10x and 100x doses caused dose- and time-dependent effects. After 30 days, the 10x dose did not cause any changes except increase in SOD activity. The 100x dose increased the activities of SOD, catalase and GR and the GSH level, but caused no alterations in lipid peroxidation (LPO) and GPx activity. After 60 days, the 10x dose did not cause any changes. The 100x dose increased LPO and decreased all the antioxidant parameters, except GSH. After 90 days, both 10x and 100x levels elevated LPO. The 10x dose decreased GSH level and activities of SOD and catalase, but not of GPx and GR, whereas the 100x dose decreased all the antioxidative systems. Overall, the present study demonstrates that the subchronic exposure of male rats to the mixture of metals via drinking water results in induction of oxidative stress and concomitant reduction in antioxidative defense system in erythrocytes at 10 and 100 times the mode concentrations of the individual metals in contaminated groundwater.

Argan oil (Argania spinosa L) Provides protection against mercuric

“…Mercury induced oxidative stress turn to severe; the inbuilt mechanism of body fails to alleviate the damage. It has been demonstrated that mercury decreases the anti-oxidative systems and produces oxidative damages via H 2 O 2 generation therby leading to lipid peroxidation [25,26]. All these possible mechanisms of mercuric chloride toxicity may lead to the formation of reactive oxygen species (ROS), as found in the present investigation.…”

Impact of cadmium on the level of hepatic metallothioneins, essential elements, and selected enzymes in the experimental rat model

“…It has been shown that the activity of GR rises up after 30 days of peroral application and after 60 and/or 90 days the activity slightly lowers. That may be connected with other probably nonenzymatic antioxidative mechanisms (Jadhav et al 2007). Domanska et al (1999) observed changes in glutathione S-transferase activity produced by repeated exposure of male Wistar rats to Cd in the response to each subsequent exposure.…”

“…Via this mechanism, GSTs participate in detoxification of xenobiotics (Board 1981). Jadhav et al (2007) had exposed male Wistar rats to the element mixture (arsenic, cadmium, lead, mercury, chromium, nickel, manganese, iron) in drinking water for 90 days. The results demonstrated that the subchronic exposure of male rats to the mixture of metals via drinking water results in induction of oxidative stress and concomitant reduction in antioxidative defense system in erythrocytes.…”

Quality Assessment of Waterside River, Ogbor Hill Aba 4: Effect of Three-Point Samples on Hepatic Histo-Morphology and Some Seric Bio-Functional Indicators of Wistar Rats

“…These changes could imply that the significantly high content of some heavy metals (lead, nickel and chromium) in notably the downstream and midstream samples of WRO may have intoxicated the rats liver resulting to the observed histomorphologic changes. Histomorphologic changes confirmed persistent toxic assault on organs in collaboration with seric chemistry results and at times as could not be detected by seric results [16,[40][41][42] . The congestion of central vein of the liver as noted in this study was consistent with hepatic response to heavy metals toxic assault in various animal models [6,7,[37][38][39]43,44] .…”