Dose dependent changes in oxidative stress, hematological variables, tissue pathology, and apoptosis following chronic sodium tungstate exposure in rats

Abstract

Tungsten (W) toxicity has been identified as one of the major health concerns in the last decade. It has been identified in few hazardous waste sites and proposed for inclusion in the Environmental Protection Agency National Priorities List. The purpose of this study was to provide biochemical basis for understanding the tungstate induced interference in different organs and blood. Male Wistar rats were exposed to the concentration of 50, 100 and 200 ppm of tungstate in drinking water for 120 days. The hematological profiling was done after 15, 30 and 120 days. The biochemical estimation of oxidative stress parameters and histopathology of different organs were performed after 120 days. Significant reduction in the WBC and RBC counts, and hemoglobin levels was observed after exposure to 200 ppm of tungstate for 120 days. Significant alterations were observed in oxidative stress markers, being more pronounced in the liver and spleen. This was consistent with elevated number of apoptotic cells in spleen, and high tungstate concentration in blood, liver and spleen. Hence, we can conclude that the free radical induced oxidative stress which alters the antioxidant response are the possible mechanisms behind tungstate toxicity as we observed alterations in hematological parameters, histopathological observations, number of apoptotic cells, and bio-distribution of W. The study provides useful data for assessing the need to conduct health checkup in individuals living near hazardous waste sites or other sites associated with W exposure. Also, it provides information for assessing the potential health risks associated with tungstate toxicity.

Keywords

• Sodium Tungstate
• Histopathology
• Apoptotic cells
• Oxidative stress markers
• Toxicity
• Rat