RESUMO
Diesel particulate extract (DPE), which is a significant constituent of airborne particle pollution, has a strong association with the development of cancer and respiratory diseases. Fulvic acid (FA), a plentiful organic macromolecule found in water, has the capability to modify particle surface charge and adsorption capacity when combined with minerals. Nevertheless, there is a scarcity of data regarding the influence of their interaction on DPE toxicity. To examine the impact of environmental factor on the toxic effects of DPE, we used the Caenorhabditis elegans (C. elegans) model to investigate the reproductive toxicity of DPE and FA on insulin signaling pathway. C. elegans were subjected to a semi-fluid medium (NGG) containing different concentrations of DPE or DPE + FA in order to assess germline apoptosis and the expression of important genes in the insulin signaling pathway. Through several mutant strains, we found that daf-2, age-1, pdk-1, akt-1 and daf-16 were involved in DPE-induced apoptosis. Furthermore, and the expression levels of these genes significantly altered. The ratio of daf-16 translocation to nucleation, as well as the amount of reactive oxygen species (ROS), exhibited a dose-response relationship, however, the presence of FA could altered these effects. The results revealed that the insulin signaling pathway plays a vital role in mediating the harmful effects caused by DPE, whereas environmental factors have a substantial impact on its toxicity. Moreover, it was noted that semi-fluid medium could effectively replicate three-dimensional exposure circumstances closely resembling those observed in actual situations.