Effect of co-exposure to multiple metals (Pb, Cd, Cr, Hg, Fe, Mn and Ni) and metalloid (As) on liver function in Swiss albino mice.

Abstract

The study examined the cumulative toxic effect of multiple elements, As, Pb, Cd, Cr, Hg, Fe, Mn and Ni on the liver function and their association with inflammation and apoptosis. To explore the health consequence of simultaneous exposure to multiple metals and metalloid, male and female Swiss Albino mice were randomly divided into 14 groups and subjected to different doses [MPL (maximum permissible limit), 1×, 5×, 10×, 50× or 100×] of metal(loid)s mixture via drinking water for 8 weeks. Data showed that combined effect of multiple elements impaired the liver function. This was associated with significant decrease in the antioxidant enzymes and the elevation in lipid peroxidation for high exposure dose of 50× and 100× (p < 0.05). The metal(loid)s mixture exposure led to significant increase (p < 0.05) in cytokines, TNF-α, IL-6 and effector caspases (3 and 6) in exposure groups above 10× dose. Histopathological observation also revealed significant damage in the hepatic tissue on exposure to high dose. Dose dependent accumulation of respective elements (As, Cd, Cr, and Pb) in the liver was observed in each of the exposure groups. However, similar dose related increment was not observed for essential metals such as Ni, Fe and Mn. Differential accumulation of metals in the liver may be attributed to the effect of co-contaminant exposure, which could affect the divalent cation absorption due to antagonism and competitive transport process. Overall findings in this study manifest the complexity of possible joint effect of co-exposure to multiple metals and metalloid on the liver function.