Oxidative stress from reflux esophagitis to esophageal cancer: the alleviation with antioxidants

The incidence of reflux esophagitis increases in world, affecting approximately 20% of Western populations and its consequent lesion, Barrett's esophagus (BE), established as the primary precursor lesion of esophageal adenocarcinoma (EAC) or Barrett associated adenocarcinoma (BAA), is also increasing in incidence in Asian countries as well as Western countries. The fact that surveillance strategies have not had a major benefit in decreasing the incidence of EAC increased attention to arrest or delay the progression of BE to EAC. Since sustained inflammation and consequent oxidative stress plays core pathogenic role in reflux esophagitis, BE, and BAA, attention paid to anti-inflammatory and antioxidative agents in the treatment of reflux esophagitis. Since the risk of esophagitis is associated with hiatal hernia, body mass index, and duodenogastric reflux, and acid exposure, lifestyle modification and agents to control gastric acidity might be mainstay for treatment, but several studies consistently showed the implication of robust oxidative stress in reflux associated esophageal diseases. In this review article, the pathogenic implication of oxidative stress will be introduced in the development of reflux esophagitis, BE, and EAC. Also, since there is great interest in complete healing of reflux esophagitis and chemoprevention to prevent or slow malignant transformation, the contribution of antioxidants or antioxidative agents, which was delivered during SFRR-Asia 2015 (Chiangmai, Thailand), will be described. Also, the molecular mechanisms how the antioxidative drugs, rebamipide, ecabet sodium, and pantoprazole exerted significant protection from acids or bile acids-associated esophagitis are included.