Background: Arsenic was used in medicine, cosmetics industry, and agriculture. Nowadays, using arsenic in endodontics has greatly declined due to the severe damage to vital pulp tissue, and periodontium. Folic acid is one of the forms of vitamin B9 and it possesses a significant antioxidant effect. Zinc performs proapoptotic, anti-inflammatory and protective antioxidant activities.
Objective: Evaluation of effect of folic acid and zinc chloride (ZnCl2) on arsenic treated pulp tissue of rats.
Methodology: Twenty-five rats were divided into five groups; each group consisted of 5 rats: Group (1); served as a control without any treatments. Experimental groups (2,3 and 4); arsenic treated group, folic acid treating in arsenic treated group and ZnCl2 treating in arsenic treated group sequentially. After 24 hours from the last dose, specimens were taken and processed for H&E, and immunohistochemical stains: Nrf2 and TNF-α, morphometric analysis and statistical analysis.
Results: Groups 1,3 and 4 showed mostly Nrf2 negative immunoreactivity in odontoblastic cell layer and faint Nrf2 immunoreactivity in pulp tissue. But group 2 had strong Nrf2 positive immunoreactivity in cytoplasm and nucleus of disorganized odontoblastic cell layer and in pulp tissue. Groups 1 and 3 showed very weak TNF-α immunoreactivity in pulp tissue. But group 2 had very strong positive TNF-α immunoreactivity in pulp tissue. While group 4 showed TNF-α negative immunoreactivity in pulp tissue.
Conclusion: As2O3 has a toxic effect on pulp tissue through increasing the reactive oxygen species. ZnCl2 has a powerful detoxification effect more than folic acid in arsenic treated pulp tissue.