Immuno-modulatory effects of macluraxanthone on macrophage phenotype and function

Macluraxanthone was previously reported to have many biological activities, including anti-cholinesterase, anti-oxidant, anti-cancer, anti-malarial and anti-inflammatory effects. The aim of the current study was to further characterise the effect of macluraxanthone on human macrophage, a type of immune cell that has been implicated in the development of various inflammatory diseases. The expression of surface markers and cytokine production by THP-1 human macrophages following treatment with macluraxanthone were investigated. Macluraxanthone was shown to promote polarisation of M1-like pro-inflammatory macrophages by increasing the percentage of macrophages expressing CD86, while decreasing their CD14, CD11b and CD80 expression. However, in the presence of the pro-inflammatory stimulus lipopolysaccharide, macluraxanthone significantly decreased TNF-α and IL-10 cytokine production.