Investigating the Effects of Sulfur Dioxide Gas on the Level of Pro - Inflammatory Cytokines IL-6 and TNF-a and Hippocampal Cell Changes in Mice

Cytokine levels increase in response to air pollution. Air pollution is one of the most important factors affecting the general health of society and has become a concern in large and industrial cities. One of the        air- polluting components is sulfur dioxide (SO2). Based on epidemiological studies, SO2 aggravates various diseases such as cardio- pulmonary, cancer, progressive neurological diseases such as Alzheimer's, etc. The purpose of this study was to investigate the effects of sulfur dioxide gas on the level of pro- inflammatory cytokines IL-6 and TNF-α and hippocampal cell changes in mice.

This research was based on an experimental-laboratory study. Twenty- Four mice were randomly divided into 4 groups (control, Experimental (a) once with a high dose, Experimental (b) one week every day for 5 minutes with a low dose, Experimental (c) 3 weeks every day for 5 minutes with a low dose). In order to expose the animals to SO2 gas, a chamber was used. After the period, the mice were anesthetized and blood samples weretaken from the heart to analyze the inflammatory factors. After the perfusion, the brain was removed from the skull and entered the passage stages. Then cutting and staining the tissue slices, the neuronal density of different hippocampus regions was examined by the dissector method, and the data were analyzed by one- way ANOVA and Tukey's supplementary test.

The results showed that the amount of IL-6 in the experimental group b (P < 0.05) and c (P < 0.001) increased significantly compared to the control group. In addition, the amount of TNF-α also increased significantly in experimental group B (P < 0.05) and C (P < 0.001) compared to the control group. Also, the neuronal density of different areas of the hippocampus decreased in all groups compared to the control group, which is more significant in the experimental group (c) (P < 0.05).

It seems that the amount of IL-6, TNF-α increased in the experimental groups that were exposed to gas. Also, the neuronal density in all areas of the hippocampus of rats in the experimental groups was lower than in the control group.