DHA inhibits pro-inflammatory cytokine release and oxidative stress induced by LPS in primary macrophages. LPS (100 ng/ml)-treated primary macrophages were treated with DHA (20 µM) for 6 h. (A) Representative images of immunofluorescence analyses performed on primary macrophages using anti-CD68 (green) and anti-F4/80 (red) antibodies. The mRNA expression levels of (B) IL-1β, (C) TNF-α and (D) IL-6 in primary macrophages were determined (n=4-6). (E) IL-1β, (F) TNF-α and (G) IL-6 protein levels in the culture supernatant of primary macrophages were determined (n=4-6). (H) ROS production, (I) MDA content, (J) SOD activity and (K) GSH content in primary macrophages were determined (n=4-6). Data are expressed as the means ± standard error of the mean. *P<0.05, **P<0.01, ***P<0.001. DHA, dihydroartemisinin; LPS, lipopolysaccharide; ROS, reactive oxygen species; MDA, malondialdehyde; SOD, superoxide dismutase; GSH, glutathione.