Houttuynia cordata Polysaccharide Ameliorates Chronic Inflammation-Induced Intestinal Impairment by Zonula Occludens-1 in Rats

This study aimed to investigate the protective effects of Houttuynia cordata polysaccharide (HCP) against chronic intestinal inflammation in rats that were subjected to low-dose lipopolysaccharide once weekly for 6 weeks. Here, administration of HCP significantly restored morphological changes in the intestine along with enhancement of antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase activities, and reduction of malondialdehyde contents. HCP treatment was also found to attenuate the inflammatory mediators nitric oxide, inducible nitric oxide synthase, total nitric oxide synthase, and interleukin-1beta (IL-l beta) and enhanced the production of short-chain fatty acids. Correspondingly, a significant elevation of zonula occludens-1 (ZO-1) was displayed in the intestine of HCP-treated rats, indicating that the intestinal mechanical barrier could be repaired by HCP treatment. Therefore, these findings suggested that HCP performed protective effects against chronic inflammation-induced intestinal impairment through alleviating inflammation, modifying the redox system, and recovering the intestinal mechanical barrier, mediated by the control of ZO-1 in rats.