Combined Effects of Fluoride and Arsenic on Mitochondrial Function in the Liver of Rat

Biochemical and/or molecular mechanisms of arsenic or fluoride toxicity in experimental animals have been widely investigated in the recent past. However, their combined effects on target cells/organelle are poorly understood. The present study was executed to delineate their combined effects on mitochondrial function in the liver of rat. Female Wistar rats (140 ± 20 g) were force fed individually or in combination with sodium arsenate (4 mg/kg body weight) and sodium fluoride (4 mg/kg body weight) for 90 days. Thereafter, established markers of mitochondrial function viz. mitochondrial lipid peroxidation, oxidative phosphorylation, ATPase, succinic dehydrogenase, and caspase-3 activity were determined. Cytochrome C release and oxidative DNA damage were also estimated in the liver of respective groups of rats. The study showed significant differences in these results amongst the three groups. Observations on parameters viz. LPO, cytochrome-C, caspase-3, and 8-OHdG suggested an antagonistic relationship between these two elements. Results on ATPase, SDH, and ADP:O ratio indicated synergism. It is concluded that As^III + F in combination may express differential effects on signalling pathways and proapoptotic/antiapoptotic proteins/genes that contribute to liver cell death. Interaction of As and F with mitochondria.