Grape Seed Polyphenols Ameliorated Dextran Sulfate Sodium-Induced Colitis via Suppression of Inflammation and Apoptosis

Abstract

Background: Ulcerative colitis (UC) is an inflammatory bowel disease. Its onset is typically gradual, usually followed by periods of spontaneous remission and subsequent relapses. Grape seed polyphenols (GSP), a natural product extracted from grape seeds, have strong anti-inflammatory functions. Objectives: In this study, we investigated whether GSP has an inhibitory effect on UC and its related mechanism or not. Methods: We induced UC by 2.5% dextran sulfate sodium (DSS) and GSP at different doses (500 and 750 mg/kg body weight per day) was administrated to the mice by gavage. Body weight, diarrhea, and bloody stool were recorded every day to evaluate disease activity index. Hemotoxylin-eosin staining and immunohistochemical staining were used to identify the histological damages and inflammatory infiltration in colon tissues. Real-time polymerase chain reaction was used to evaluate mRNA expression of interleukin (IL)-6, IL-1 beta, and tumor necrosis factor (TNF)-alpha and the expression of phosphorylated-signal transducer and activator of transcription 3 (STAT3) and STAT3 were assessed by western blot. The immunofluorescent assay was used to evaluate the apoptosis of intestinal epithelial cells (IECs). Results: GSP could alleviate the loss of body weight, diarrhea, bloody stool, the mucosal damage, and inflammatory infiltration. GSP could also downregulate the mRNA expression of inflammatory cytokines IL-6, IL-1 beta, and TNF-alpha as well as the phosphorylation of STAT3 and ameliorate the apoptosis of IECs. Conclusions: Our study suggests that GSP has protective effects against DSS-induced UC, which may through suppression of inflammation and apoptosis.