Potential Protective Effect of Riboflavin Against Pathological Changes in the Main Organs of Male Mice Induced by Fluoride Exposure

Long-term exposure to excessive fluorine could cause damage to various tissues and organs in human and animals. However, there is no effective antidote to prevent and cure fluorosis except for avoiding fluoride intake. As an essential nutrient, riboflavin (VB2) has been identified to relieve oxidative stress and inflammation in animal tissues caused by other toxic substances, whether it can alleviate the damage caused by fluoride is unknown. For this, 32 ICR male mice were allocated to four groups of eight each. They were treated with 0 (distilled water), 100 mg/L sodium fluoride (NaF), 40 mg/L VB2, and their combination (100 mg/L NaF plus 40 mg/L VB2) via the drinking water for 90 consecutive days, respectively. The content of bone fluoride and the histomorphology of the main organs including liver, kidney, cerebral cortex, epididymis, small intestine, and colon were evaluated and pathologically scored. The results found that fluoride caused the pathological changes in liver, kidney, cerebral cortex, epididymis, small intestine, and colon at varying degrees, while riboflavin supplementation reduced significantly the accumulation of fluoride in bone, alleviated the morphological damage to cerebral cortex, epididymis, ileum, and colon. This study provides new clues for deeply exploring the mechanism of riboflavin intervention in fluorosis.