Chitosan-tripolyphosphate/Eudragit® S100 nanoparticles containing quinic acid and ferulic acid ameliorate ulcerative colitis in rats via modulating Th17 cells and pro-inflammatory cytokines.

BACKGROUND: Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disease (IBD) that causes superficial mucosal inflammation. Ferulic acid (FA) and quinic acid (QA) have wide-spectrum biological activities such as anti-inflammatory and antioxidant. Therefore, the present study aimed to anti-inflammatory effects of FA and QA in chitosan nanoparticles cross-linked by tripolyphosphate/Eudragit® S100 (CS-TPP/EU S100) as a colon drug delivery system for UC.

MATERIALS AND METHODS: Eighty rats were randomly divided into ten groups (n = 8). Colitis was induced by intrarectal administration of 4 % AA, and rats orally received FA, QA, and CS-TPP/EU S100 NPs. The rats' rectum was evaluated for macroscopic disease activity index (DAI) score and microscopic damage. Then, Th17 cell frequency and related cytokines expression levels were quantified by immunofluorescence assay and real-time PCR, respectively. Pro-inflammatory cytokines were measured by ELISA.

RESULTS: Treatment with mesalazine, FA, FA/CS-TPP/EU S100 NPs, QA, QA/CS-TPP/EU S100 NPs, FA/QA, and FA/QA/CS-TPP/EU S100 NPs significantly increased colon length and decreased macroscopic damage, DAI score, colon weight, histological damage score, and Th17 cell frequency. Additionally, cytokine expression and pro-inflammatory cytokines were downregulated compared to the UC group.

CONCLUSION: FA/QA/CS-TPP/EU S100 NPs showed the best effect in the treatment of UC by modulating Th17 cells and pro-inflammatory cytokines.