Biochemical, histopathological and immunohistochemical investigation of carnosine effects on formaldehyde-induced oxidative damage and irisin hormone alterations in lung and liver of rats

Biochemical, Histopathological and Immunohistochemical Investigation of Carnosine Effects on Formaldehyde-Induced Oxidative Damage and Irisin Hormone Alterations in Lung and Liver of Rats Objective: The amount of formaldehyde (FA) exceeding the physiological doses damages the tissues, reduces the antioxidant capacity and impairs the regulation of the energy metabolism. Carnosine, an antioxidant molecule, may serve to offset the harmful effects of formaldehyde exposure. Additionally, since formaldehyde impairs the normal physiology of the energy metabolism, there may be a correlation between irisin amount and formaldehyde exposure. Therefore, the present study aims to examine whether carnosine (100 mg/kg/day) has favorable effects on liver and lung tissues of male rats exposed to mild, moderate, and high doses of formaldehyde (8 h/day; 5 days/week) and how irisin quantities in these tissues and the serum change after carnosine supplementation and to show how carnosine supplementation affects apoptosis and total oxidant and antioxidant capacity. Materials and Methods: The study included 48 Sprague-Dawley type male rats, weighing 260-280 gr and 8-10 weeks of age. Irisin levels of the serum, liver and lung tissue supernatants were analyzed by ELISA, while the REL method was used to determine total oxidant/antioxidant capacity. Irisin production by the tissues was detected immunohistochemically. Results: Increasing doses of FA decreased serum and tissue irisin and total antioxidant levels relative to the controls, as also to increases in TUNEL expressions, total oxidant level, oxidant and apoptotic indices. Irisin expression was seen in Kupffer cells of the liver and parenchymal cells of the lungs. Conclusion: While FA exposure reduces irisin levels and total oxidant capacity in the serum, liver and lung tissues of rats in a dose-dependent manner and increases the total antioxidant capacity; carnosine supplementation reduces the oxidative stress and restores the histopathological and biochemical signs. Keywords: Rat, Formaldehyde, Carnosine, Irisin, TAS/TOS, TUNEL.