Protective effect of chitin oligosaccharides against lipopolysaccharide-induced inflammatory response in BV-2 microglia

Chitin oligosaccharides (NA–COS) of two different molecular weight ranges (below 1 and 1–3 kDa) were examined for their capabilities against lipopolysaccharide-induced inflammatory responses in BV-2 murine microglia. It was found that NA–COS reduced the level of nitric oxide (NO) and prostaglandin E2 (PGE2) production by suppressing the expression of NO synthase (iNOS) and cyclooxygenase (COX)-2 without significant cytotoxicity. Furthermore, the inhibitory effects of NA–COS on generation of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were determined. Notably, NA–COS exerted anti-inflammatory activities via blocking degradation of inhibitor of kappaB-alpha (IκB-α), translocation of nuclear factor (NF)-κB, and phosphorylation of mitogen-activated protein kinases (MAPKs) in a dose-dependent manner. These findings provide mechanistic insights into the anti-inflammatory and neuroprotective actions of NA–COS in BV-2 microglia.