THE EFFECT OF FORMALDEHYDE ON THE LIVER OF ADULT MALE ALBINO RATS AND POSSIBLE PROTECTIVE ROLE OF VITAMIN C

Background: Formaldehyde is found in different kinds of medicine and industrial products, cigarette smoke, and even numerous vegetables, fruits and seafood that have been illegally preserved with formalin. The water soluble vitamin C is a strong antioxidant that scavenges free radicals and other reactive nitrogen and oxygen species. Even in small amounts, vitamin C can defend nucleic acids, lipids and proteins against oxidative damage. Objectives: the aim of this study is to elucidate the possible changes that take place in the liver of adult male albino rats after intraperitoneal injection of formaldehyde and the possibility of oral vitamin C’s hepatoprotectivity against it. Design: forty-five adult male albino rats were utilized in this work. These animals were allocated randomly into three main groups. Group I (control groups) included 3 subgroups each contained 9 rats : –ve control received no treatment , +ve control which were injected intraperitoneally by 1 ml of  distilled water  for 10 days and vit.C +ve control group which received a daily dose of ascorbic acid (100mg/kg bw) dissolved in distilled water by gavage for 10 days. Group ΙΙ: contained 9 rats, which were injected intraperitoneally with a daily dose of formaldehyde (10mg/kg BW) for 10 days. Group IΙΙ: contained 9 rats that were injected intraperitoneally with a daily dose of formaldehyde (10mg/kg BW) concomitantly with daily dose of ascorbic acid (100mg/kg BW) by gavage for 10 days. By the end of the experiment, blood samples were collected for biochemical study of ALT (Alanine aminotransferase), AST (Aspartate aminotransferase) and albumin and all animals were anaesthetized by ether inhalation. Liver specimens were dissected out and weighed then subjected to histopathological, immunohistochemistry, and morphometrical examination. Results: Administration of formaldehyde at a dose of 10 mg/kg caused increase in serum activities of ALT and AST ,but regarding albumin ,it remained unaffected .It caused increase in the liver weights and  induced several histopathological changes in the liver of adult male albino rats as congested dilated central veins, portal veins and blood sinusoids with increase in the thickness of the wall of the portal vein. Meanwhile, some hepatic lobules showed multiple necrotic foci around central and portal veins. On the other hand, vit.C partially improved the state of oxidative stress as evidenced by iNOS (inducible nitric oxide synthase) immunohistochemistry. It also reduced the degree of hepatic fibrosis as evidenced by Mallory trichrome histochemical staining. Conclusion: Exposure to formaldehyde led to pronounced hepatic damage which is partially limited by vit.C coadministration. Recommendations: Many special precautions should be taken to limit the occupational and environmental exposure and the level of food and water contamination with formaldehyde and use vit.C as a supplement to limit the toxic effects on the liver.