Immunotoxicity study of crude oil gaseous pollutants in development of the rat embryonic and neonates' development

Environmental pollution, especially oil and gas pollutants, has devastating effects on maternal and fetal health. In this study, the direct effects of petroleum gases on the development and function of the immune system during prenatal and neonatal periods in rats were investigated. Pregnant rats (N=36) were divided into two groups: one exposed to pollutants and one serving as the control group. The group of pollutants was exposed to oil vapors in the vivarium compartment for 5 hours per day starting from the first day of pregnancy. Fetal spleen samples were taken on day 20 of embryonic life to investigate the expression of tumor necrosis factor alpha (TNF-α), interferon beta-1 (IFN-β1), alpha lymphotoxin (LT-α), and Transforming Growth Factor-β1 (TGF-β1) genes. The total serum immunoglobulins and antibody titer to sheep red blood cells were evaluated when the neonates were 45 days old. Innate immune responses were investigated in terms of serum bactericidal, lysozyme, myeloperoxidase, anti-protease, and complement activity. The expression of the mentioned genes in newborns was also evaluated at the ages of 15 and 30 days compared to the control group. The results indicated a significant decrease in the activity of lysozyme, complement, and myeloperoxidase, as well as a non-significant reduction in the serum bactericidal activity and humoral immune response of the pollutant group compared to the control group. The expression levels of LT-α and IFN-β1 were reduced, while the expressions of TNF-α, IL-1, and IL-10 were elevated in the embryos exposed to pollutants. An age-related increase in TNF-α and TGF-β1 was observed in the offspring of the pollutant group. In conclusion, petroleum vapors have been shown to have a destructive and significant effect on the innate, humoral, and cellular immune responses of fetuses and neonates. The mechanisms involved in these destructive effects can be investigated in future studies.