Anti-inflammatory effects of β-1,3-1,6-glucan derived from black yeast Aureobasidium pullulans in RAW264.7 cells

β-glucan derived from the black yeast Aureobasidium pullulans (A. pullulans) is one of the natural products attracting attention due to its high potential for application as a functional food and pharmaceutical. A highly soluble, low-molecular-weight β-glucan (LMW-AP-FBG) was obtained from the fermentation culture medium of A. pullulans via mechanochemical ball milling. We investigated the anti-inflammatory effect of LMW-AP-FBG using lipopolysaccharide (LPS)-stimulated murine macrophages (RAW264.7 cells). LMW-AP-FBG significantly inhibited the production of inflammatory cytokines including TNF-α, IL-6, and IL-1β, as well as nitric oxide (NO) and prostaglandin E2 (PGE2). The anti-inflammatory mechanism involved suppression of NF-κB and MAPK signaling pathways, and inhibition of COX-2 and iNOS gene expression.