High molecular weight hyaluronic acid drastically reduces chemotherapy-induced mucositis and apoptotic cell death

Oral and intestinal mucositis (OIM) are debilitating inflammatory diseases initiated by oxidative stress, resulting in epithelial cell death and are frequently observed in cancer patients undergoing chemo-radiotherapy. There are currently few preventative strategies for this debilitating condition. Therefore, the development of a safe and effective mucositis mitigating strategy is an unmet medical need. Hyaluronic acid (HA) preparations have been tentatively used in oral mucositis. However, the protective effects of HA in chemotherapy-induced mucositis and their underlying mechanisms remain to be fully elucidated. This study aimed to assess these mechanisms using multiple formulations of enriched HA (Mucosamin^®), cross-linked (xl-), and non-crosslinked high molecular weight HA (H-MW-HA) in an oxidative stress-induced model of human oral mucosal injury in vitro and an in vivo murine model of 5-flurouracil (5-FU)-induced oral/intestinal mucositis. All tested HA formulations protected against oxidative stress-induced damage in vitro without inducing cytotoxicity, with H-MW-HA also significantly reducing ROS production. Daily supplementation with H-MW-HA in vivo drastically reduced the severity of 5-FU-induced OIM, prevented apoptotic damage and reduced COX-2 enzyme activity in both the oral and intestinal epithelium. In 5-FU-injected mice, HA supplementation also significantly reduced serum levels of IL-6 and the chemokine CXCL1/KC, while the serum antioxidant activity of superoxide dismutase was elevated. Our data suggest that H-MW-HA attenuates 5-FU-induced OIM, at least partly, by impeding apoptosis, inhibiting of oxidative stress and suppressing inflammatory cytokines. This study supports the development of H-MW-HA preparations for preventing OIM in patients receiving chemotherapy.

Higher expression of Th1/Th2-related cytokines in the intestine of Wistar rats with ligature-induced periodontitis

OBJECTIVE

This study aimed to investigate the impact of ligature-induced periodontitis (LIP) on histopathological and immunological outcomes in the colon of Wistar rats.

BACKGROUND

It has been repeatedly shown that inflammatory bowel disease (IBD) patients are at higher risk of developing periodontitis and presenting worse oral health than non-IBD patients. However, whether the chronic inflammatory process around teeth contributes to the pathophysiology of IBD needs to be further explored.

MATERIALS AND METHODS

Thirteen Wistar rats were allocated into LIP (n = 7) and controls (n = 6). Half of the colon was processed for histopathological analyses and immunohistochemical (CD45); the other half was homogenized for immunological analyses. Periodontal destruction was confirmed by measuring the distance from the cementum-enamel junction to the mandible's apical position of the mesial interproximal bone. The immunological analyses were performed with the Bio-Plex Th1/Th2 assay.

RESULTS

There was a significantly higher interproximal bone loss in LIP compared to controls. The LIP group showed a moderate infiltrate of inflammatory cells, predominantly mononucleated cells in the intestinal tissues. There was significantly higher expression of GM-CSF, IFN-γ, IL-1α, IL-1β, IL-2, IL-4, IL-5, IL-10, IL-12 (p70), IL-13, and TNF-α in the intestinal tissues of LIP group compared to controls.

CONCLUSION

Ligature-induced periodontitis was associated with an overexpression of Th1/Th2-related cytokines in the colon of Wistar rats.