Epigenetic changes in inflammatory genes and the protective effect of cooked rhubarb on pancreatic tissue of rats with chronic alcohol exposure

Abstract

Chronic alcohol consumption, which is observed worldwide, can damage pancreatic tissue and promote pancreatitis. Rhubarb is a widely used traditional Chinese herbal medicine for treating pancreatitis in China. However, few pharmacological studies have investigated its epigenetic regulation. In this study, we investigated whether chronic exposure to alcohol can alter inflammatory gene expression and the epigenetic regulation effect of cooked rhubarb in the pancreatic tissue of rats. First, changes in inflammatory cytokine DNA methylation (IL-10, IL-1α, TNF-α, NF-κB and TGF-β) were detected in pancreatic tissue of Sprague-Dawley rats with varying alcohol exposure times (4, 6, 8, or 12 weeks), and then with varying doses of cooked rhubarb treatment (3, 6, or 12 g/day). DNA methylation levels, related RNA concentrations and protein expression of specific inflammatory cytokines, and histopathological score were analysed in pancreatic tissue of Sprague-Dawley rats. The results showed that chronic alcohol exposure (8 weeks) reduced the level of IL-1α DNA methylation and increased its protein expression in acinar cells (P < 0.05). In the acinar cells, the level of IL-10 DNA methylation increased, resulting in a reduction of protein expression (P < 0.05). Simultaneously, chronic alcohol exposure increased the pathological damage to the pancreas (P < 0.05). Finally, cooked rhubarb treatment (3 g/kg/day) effectively alleviated these changes in pancreatic tissue from chronic alcohol exposure (P < 0.05). These results indicate that chronic exposure to alcohol leads to changes in DNA methylation and protein expression of inflammatory genes, and cooked rhubarb may have a protective effect on the pancreatic tissue of rats.