Sanleng acid is an unsaturated fatty acid compound that can be isolated from the hexane extract of Magnolia sieboldii (MsHE). MsHE inhibits the expression of inflammatory mediators like COX-2 and pro-inflammatory cytokines such as TNF-α and IL-1β, while enhancing the expression of tight junction proteins (claudin-4, claudin-5) to protect epithelial cell barrier function, thereby exhibiting anti-inflammatory activity. This compound may be relevant for research related to reflux esophagitis (RE).