Cytotoxic effect and role of exogenous antioxidants in carpet dust mediated toxicity in rat hepatocytes in vitro.

Carpet industries bear a great deal of economic and commercial significance in India. In order to safe guard the workers against the health hazards caused by dust in their occupational environment; it necessitates studying the biological importance of these dusts. The present study was designed to investigate the toxicity of carpet dust (knotted and tuffted) on isolated rat hepatocytes. The hepatocytes were isolated by collagenase perfusion method and cells were incubated with different concentration of carpet dust (100-5000 microg/10(6) cells) with various time (30-180 min) intervals. An exogenous antioxidant vitamin-E also used to find out the role of antioxidants and free radical production in carpet dust mediated toxicity. Cell viability by trypan blue exclusion and leakage of enzyme lactate dehydrogenase (LDH) were determined. Reduced glutathione (GSH), formation of thiobarbituric acid reactive substance (TBARS) were also measured. A significant decrease in the cell viability was observed after 60, 180 min upon incubation with tuffted carpet dust, while knotted carpet dust caused a significant decrease in the viability after 180 min. LDH leakage was parallel to the cell viability. Thiobarbituric acid reactive substance was significantly increased at 30 and 60 min with carpet dust treated hepatocytes. Dust at 1000 and 5000 microg dose level showed significantly increased formation of TBARS at 30 min incubation. However, when hepatocytes were co-incubated with carpet dust and Vit-E (10, 15 microM), a significant decrease in LDH release and TBARS production was observed while 15 microM Vit-E showed an enhanced protection than 10 microM Vit-E treated hepatocytes. The effect of carpet dust on cell viability, LDH leakage, TBARS production, GSH depletion was time and dose-dependent. Moreover, we observed that tuffted carpet dust causes greater effect than knotted one on the above mentioned parameters. Our studies also revealed that Vit-E in culture media diminishes the carpet dust mediated toxicity.