Pre-and postnatal exposition to fluorides induce changes in rats liver morphology by impairment of antioxidant defense mechanisms and COX induction

Introduction: Fluorides are common in the environment and are absorbed mostly in the stomach and gut, it can easily move through cell membranes and its accumulation can cause harmful effects in skeletal and soft tissues. One of the most important F- accumulation sites is the liver. The aim of this study was to determine whether F- can cause inflammation in rat liver by affecting the activity of antioxidant enzymes and changes in the synthesis of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2). Materials and methods: An in vivo model of prenatal and postnatal exposure to sodium fluoride (NaF) was used to carry out the experiment. Animals from control group received tap water to drink, while animals exposed to F-received drinking water containing NaF, 50 mg/L. In serum and liver we analyzed F-concentration, in liver - antioxidant enzymes activity, PGE2 and TXB2 concentration and immunolocalization of COX1 and COX2 proteins were measured. Results: We observed significant changes in F-concentration only in liver. The results of this study showed that F-affects antioxidant enzymes activity, COX2 protein expression and PGE2 synthesis in liver. Also, in some regions of the liver of rats exposed to F-, the hepatocytes were diffusely altered, with changes resembling microvesicular steatosis. Conclusion: Chronic exposure to F- during development causes an accumulation of this element in the liver and changes in antioxidant enzymes activity and cyclooxygenase expression. Long term exposure to this element is toxic to the liver and can cause disturbances in its homeostasis. (C) 2018 Elsevier Ltd. All rights reserved.