Anti-inflammatory effects of silkworm hemolymph on lipopolysaccharide-stimulated macrophages

Abstract

Macrophages participate in several inflammatory pathologies such as sepsis and arthritis. We investigated the effect of silkworm hemolymph (SH) on the LPS-induced pro-inflammatory macrophages. SH inhibits LPS-induced nitric oxide (NO) production in RAW 264.7 cells and murine peritoneal macrophages. The decreased NO was reflected as a decreased amount of inducible nitric oxide synthase (iNOS) mRNA and protein. It was also found that SR inhibited pro-inflammatory cytokines, IL-1 beta, IL-6, and TNF-alpha production. To elucidate the mechanism by which SR inhibits NO production and iNOS expression, we investigated that SR suppressed I kappa B phosphorylation, which leads to the activation of NF-kappa B followed by degradation of I kappa B. This observation suggests that SH is a potential therapeutic modulator for inflammation-associated disorders.