Potential role of nuclear factor-kappaB in the induction of nitric oxide and tumor necrosis factor-alpha by oligochitosan in macrophages.

Oligochitosan, having an average molecular weight of 1000 Da and a degree of N-acetylation below 15%, can be obtained by either chemical or enzymic hydrolysis of chitosan. The present investigation demonstrated that oligochitosan can significantly increase the activity of inducible nitric oxide synthase (iNOS) and induce the synthesis of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) in macrophages. Moreover, nuclear factor-kappaB (NF-kappaB) protein levels in nuclear extract are increased in response to oligochitosan. Blocking NF-kappaB with specific inhibitor results in decreased levels of NO and TNF-alpha. These results indicate that NF-kappaB plays a potential role in the induction of NO and TNF-alpha by oligochitosan in macrophages.