Effects of chitosan on oxidative stress and related factors in hemodialysis patients

Abstract

In recent world-wide studies, chitosans were tested as a dietary supplement for inhibiting the absorption of certain lipids and bile acids. We previously demonstrated the antioxidative and renoprotective potential of chitosan supplementation in chronic renal failure using 5/6 nephrectomized rats. In this study, we report the effects of chitosan on oxidative stress and related factors in hemodialysis patients. The ingestion of chitosan over a 12-week period resulted in a significant decrease in serum indoxyl sulfate and phosphate levels, compared with the levels prior to the start of the study. The ingestion of chitosan also resulted in a lowered ratio of oxidized to reduced albumin and a decrease in the level of advanced oxidized protein products. In in vitro studies, chitosan solutions were found to bind 38.5% of the indoxyl sulfate and 17.8% of the phosphate, respectively. Further, the oxidized albumin ratio was correlated with serum indoxyl sulfate levels in vivo. These results suggest that the ingestion of chitosan results in a significant reduction in the levels of pro-oxidants, which include uremic toxins, in the gastrointestinal tract, thereby inhibiting the subsequent development of oxidative stress in the systemic circulation. In addition, the long-term ingestion of chitosan has the potential for use in treating hyperphosphatemia in hemodialysis patients.