Effect of antioxidants and biotransformation inhibitors on 1,2,3‐trichlorobenzene nephrotoxicity in vitro

Chlorinated benzenes are used as chemical intermediates in the manufacture of a wide range of commercial products and are environmental contaminants in soil and waste water. Toxicity induced by chlorobenzenes includes nephrotoxicity with in vivo nephrotoxicity associated with rat α2u‐globulin. A recent study in our laboratory demonstrated that trichlorobenzenes (TCBs) are directly toxic to the kidney, with 1,2,3‐TCB being the most potent nephrotoxicant in isolated renal cortical cells (IRCC) from male Fischer 344 rats. The purpose of this study was to evaluate several antioxidants and inhibitors of biotransformation pathways to determine their impact on 1,2,3‐TCB nephrotoxicity. IRCC (~4 million cells/ml; 3 ml) were incubated with shaking at 37°C under a 95% oxygen/5% carbon dioxide atmosphere with 1,2,3‐TCB (1.0 mM) or vehicle (dimethyl sulfoxide) for 60 min with or without a pretreatment. General cytotoxicity was determined by assessing trypan blue exclusion of IRCC, measuring changes in lactate dehydrogenase (LDH) release, and quantitating ATP levels. 1,2,3‐TCB cytotoxicity was reduced by all antioxidants (ascorbate, glutathione, alpha‐tocopherol) and general cytochrome P450 (CYP) inhibitors (metyrapone and piperonyl butoxide), but not by peroxidase inhibitors (mercaptosuccinate, indomethacin). Several selective CYP inhibitors (isoniazid, omeprazole, sulfaphenazole, oleandomycin, thiotepa) were tested, and all provided some protection against 1,2,3‐TCB cytotoxicity. Protective pretreatments also generally attenuated 1,2,3‐TCB‐induced reductions in ATP levels. These results suggest that free radicals/oxidative stress and CYP‐mediated biotransformation play a role in 1,2,3‐TCB nephrotoxicity in vitro. Support or Funding Information Supported in part by NIH grant P20GM103434. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .