Use of fucoidan to treat renal diseases: A review of 15 years of clinic studies

Fucoidan is a sulfated polysaccharide extracted from brown seaweeds. Studies have shown that fucoidan has curative effects on the chronic renal failure, acute kidney injury, and diabetic nephropathy both in vitro and in vivo. Saccharina japonica is the most economically important brown seaweed cultivated in China and is consumed as a marine vegetable in East Asia. Over the past thousand years, Chinese people have traditionally used this plant to cure edema, a symptom of kidney diseases. The fucoidan extracted from Saccharina japonica is composed primarily of fucose and galactose with smaller amounts of other monosaccharides. Structure–activity relationship studies reveal that the molecular weight, monosaccharide compositions, the sulfation degree and the positions of sulfates influences the renoprotective activity. Low molecular weight fucoidan exhibits better activity than fucoidan. Pharmacological studies indicate that fucoidan inhibits renal fibrosis and glomerular sclerosis by reducing the accumulation of extracellular matrix. In addition, fucoidan reduces the inflammatory response and P-selectin expression, maintains the glomerular basement membrane and glomerular structural integrity, improves glomerular filtration function, and protects renal glycosaminoglycans from abnormal degradation. The effective constituent of Haikun Shenxi capsule (HSC) is the fucoidan extracted from Saccharina japonica. HSC was approved for treating renal diseases by the Chinese Food and Drug Administration in 2003. Based on the results of peer-reviewed publications, we will recapitulate the structure, pharmacology, reported clinical cases, clinical efficacy, and future perspectives of HSC. This review will summarize the knowledge of HSC gained in China to stimulate in-depth academic and clinical studies of HSC world widely.