Therapeutic Potential of Oligo-Fucoidan in Mitigating Peritoneal Dialysis-Associated Fibrosis

Peritoneal dialysis (PD) serves as a home-based kidney replacement therapy with increasing utilization across the globe. However, long-term use of high-glucose-based PD solution incites repeated peritoneal injury and inevitable peritoneal fibrosis, thus compromising treatment efficacy and resulting in ultrafiltration failure eventually. In the present study, we utilized human mesothelial MeT-5A cells for the in vitro experiments and a PD mouse model for in vivo validation to study the pathophysiological mechanisms underneath PD-associated peritoneal fibrosis. High-glucose PD solution (Dianeal 4.25%, Baxter) increased protein expression of mesothelial–mesenchymal transition (MMT) markers, such as N-cadherin and α-SMA in MeT-5A cells, whereas it decreased catalase expression and stimulated the production of reactive oxygen species (ROS). Furthermore, macrophage influx and increased serum pro-inflammatory cytokines, such as IL-1β, MCP-1, and TNF-α, were observed in the PD mouse model. Interestingly, we discovered that oligo-fucoidan, an oligosaccharide extract from brown seaweed, successfully prevented PD-associated peritoneal thickening and fibrosis through antioxidant effect, downregulation of MMT markers, and attenuation of peritoneal and systemic inflammation. Hence, oligo-fucoidan has the potential to be developed into a novel preventive strategy for PD-associated peritoneal fibrosis.