Antioxidant and renoprotective activity of chitosan in nephrectomized rats.

The effect of chitosan on oxidative stress and chronic renal failure was investigated using 5/6 nephrectomized rats. The ingestion of chitosan over a 4-week period resulted in a significant decrease in total body weight, glucose, serum creatinine and indoxyl sulfate levels (P=0.0011, P=0.0006, P=0.0012, and P=0.0005, respectively), compared with the non-treated nephrectomized group. The ingestion of chitosan also resulted in a lowered ratio of oxidized to reduced albumin (P=0.003) and an increase in biological antioxidant potential (P=0.023). Interestingly, 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, such as uremic toxins, in the gastrointestinal tract, thereby inhibiting the subsequent development of oxidative stress in the systemic circulation.The effect of chitosan on oxidative stress and chronic renal failure was investigated using 5/6 nephrectomized rats. The ingestion of chitosan over a 4-week period resulted in a significant decrease in total body weight, glucose, serum creatinine and indoxyl sulfate levels (P=0.0011, P=0.0006, P=0.0012, and P=0.0005, respectively), compared with the non-treated nephrectomized group. The ingestion of chitosan also resulted in a lowered ratio of oxidized to reduced albumin (P=0.003) and an increase in biological antioxidant potential (P=0.023). Interestingly, 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, such as uremic toxins, in the gastrointestinal tract, thereby inhibiting the subsequent development of oxidative stress in the systemic circulation

Design and Evaluation of An Extended-Release Olmesartan Tablet Using Chitosan/Cyclodextrin Composites

Sustained-release olmesartan tablets (OLM) were prepared by the simple, direct compression of composites of anionic sulfobutyl ether-β-cyclodextrin (SBE-β-CD) and cationic spray-dried chitosan (SD-CS), and were evaluated for use as a sustained release preparation for the treatment of hypertension. An investigation of the interaction between OLM and SBE-β-CD by the solubility method indicated that the phase diagram of the OLM/SBE-β-CD system was the AL type, indicating the formation of a 1:1 inclusion complex. The release of OLM from tablets composed of the SD-CS/SBE-β-CD composite was slow in media at both pH 1.2 and at 6.8. The in vitro slow release characteristics of the SD-CS/SBE-β-CD composite were reflected in the in vivo absorption of the drug after normal rats were given an oral administration of the preparation. Furthermore, the SD-CS/SBE-β-CD composite continuously increased the antihypertensive effect of OLM in hypertensive rats, compared with that of the drug itself. These results suggest that a simple mixing of SD-CS and SBE-β-CD can be potentially useful for the controlled release of a drug for the continuous treatments of hypertension