Cytotoxicity of Airborne Particulates Sampled Roadside in Rodent and Human Lung Fibroblasts

抄録

The number of diesel-powered vehicles has been increasing in Japan in recent years. And chronic exposure to relatively low levels of diesel exhaust may be a risk factor for respiratory diseases. It has been demonstrated that the airborne particulates sampled at a roadside contain exhaust from diesel engines. The present study has been undertaken to evaluate the cytotoxicity of airborne particulates in human and Chinese hamster lung fibroblast cell lines (WI-38 and CHL/IU). Conversion of mitochondrial MTS, leakage of lactate dehydrogenase (LDH), and the effect on cell proliferation curves were monitored. A dose–related effect of airborne particulate extracts was observed in MTS and LDH leakage assay with both cell lines. Crude extract was most cytotoxic in the MTS assay and had a significant effect on cell proliferation. The response of extracts and fractions of these extracts on MTS assay were similar to the effect on cell proliferation in both cell systems. An increase in LDH leakage was detected in all extracts and fractions except crude extract. In comparison, CHL/IU proved to be more sensitive than WI-38 in MTS assay, but most extracts and fractions were more toxic to WI-38 in LDH leakage assay. These results suggest that even a small amount of substances in airborne particulates was toxic to both cell systems.