TOXIC EFFECTS OF FORMALDEHYDE ON CELLULAR IMMUNITY AND POSSIBLE RELATIONSHIP TO ITS RISK OF CARCINOGENESIS: AN EXPERIMENTAL STUDY

El-Nagdy, Samah Adel; Elgezawy, Ebtesam; Nasif, Khalid

doi:10.21608/zjfm.2019.20232.1043

TOXIC EFFECTS OF FORMALDEHYDE ON CELLULAR IMMUNITY AND POSSIBLE RELATIONSHIP TO ITS RISK OF CARCINOGENESIS: AN EXPERIMENTAL STUDY

Document Type : Original Article

Authors

¹ Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Zagazig University, Zagazig

² Clinical Pathology Dept., Assiut University Hospitals ,Assiut

³ Department of Medical biochemistry - faculty of medicine -Minia university

10.21608/zjfm.2019.20232.1043

Abstract

Exposure to formaldehyde (FA) can occurs either in the environment or in workplaces due to its common use in laboratory, industry, household and cosmotic products. This study was carried out to assess toxic effects of subacute exposure to FA on immune system in adult male albino rats and possible relationship to its risk of carcinogenesis. Methods: Fifty adult male albino rats were used for 28 days as follow: Group I: (20 rats) subdivided equally into group Ia negative control and group Ib positive control. Formaldehyde group: included 30 rats divided equally into groups II, III & IV received FA by oral gavage at doses of 20, 40 and 80 mg/kg respectively. Methods: At the end of the study, spleen of each rat was dissected and subjected to histopathological examination, immunohistochemical staining for CD4+ and comet assay. Blood samples were withdrawn and used for evaluation of T-lymphocytes subsets (CD3+, CD4+ and CD8+), CD19+ B-lymphocytes and CD56+ natural killer (NK) cells by flow cytometric analysis and cytokines profiles of interleukin 10 (IL-10) & interferon-gamma (IFN-γ) by enzyme-linked immunosorbent assay (ELISA) technique. Results: Histopathological and immunohistochemical studies showed decrease in the size of lymphocytes follicles with congestion of sinusoids and decreased expression for CD4+ in FA treated rats. Comet assay detected DNA damage in splenocytes of FA group. There was significant decrease in all T-lymphocytes subsets in groups III &IV with no significant difference was detected in group II. B- lymphocytes showed a significant increase in groups III & IV, however NK cells revealed a significant decrease only in group IV. Assessment of cytokines detected a significant increase in IL-10 in all FA-treated rats, while IFN-γ was decreased in groups III & IV. Conclusion: Formaldehyde exposure resulted in a dose-dependent immunotoxic effects and these effects may be related to its risk of carcinogenesis.

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