Anti‐inflammatory effect of Antirrhinum majus extract in lipopolysaccharide‐stimulated RAW 264.7 macrophages

Antirrhinum majus (AM) has attracted attention as a rich source of phytochemicals, which are beneficial for human health. However, the anti‐inflammatory effects of AM have not been studied scientifically. Therefore, we investigated the antioxidative properties and anti‐inflammatory effects of AM extract (AME) in lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophages. AME showed high radical‐scavenging ability. Viability of RAW 264.7 cells was not significantly altered by AME at the concentrations of 0–300 µg/ml. LPS‐induced nitric oxide (NO) production was decreased by treatment with 0–300 µg/ml AME in a concentration‐dependent manner. AME pretreatment significantly inhibited the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) in a concentration‐dependent manner. AME also considerably inhibited the mRNA and protein expression of inflammatory cytokines, such as tumor necrosis factor‐a (TNF‐α), interleukin‐1 β (IL‐1β), and interleukin‐6 (IL‐6). These findings provide a foundation for further studies and use of AM in nutraceuticals.