Background: Formaldehyde (FA) is a common indoor and outdoor pollutant found in many products. The toxicity of formaldehyde is of concern to all who work closely with it such as embalmers, anatomists, histology technicians, and medical students. Omega-3 in fish oil is one of the most important polyunsaturated fatty acids (PUFA) that have anti-inflammatory and antioxidant activity. Materials and methods: Thirty adult male albino rats were divided into three equal groups. Group, I was a control group, Group II rats were exposed to formaldehyde inhalation for 4 weeks. Group III were exposed to formaldehyde inhalation and were administered orally with a 300mg/kg/day Omega-3 for 4 weeks. After 24 hr of the last dose, the animals were dissected. Hearts and lungs were processed for examination after Haematoxylin and eosin, Masson trichome and immunohistochemical stains. Results: The rats treated with formaldehyde inhalation showed significant changes in the normal architecture of both lung and heart. The lung showed congestion and mass appeared on one lobe and increase in the area percent of collagen fibers. Immune-expression of tumor necrosis factor-alpha (TNF-α), and caspase- 3 were increased in the lung and heart compared to the control. Omega-3 fatty acids can ameliorate the pathological changes, decrease the fibrosis and the immune-expression in both lung and heart.
Conclusion: Formaldehyde was associated with many histopathological changes in both lung and heart and the Omega-3 can ameliorate these changes.