Cardamonin attenuates phorbol 12-myristate 13-acetate-induced pulmonary inflammation in alveolar macrophages

Pulmonary inflammation involves complex immune responses in which alveolar macrophages release pro-inflammatory proteins and cytokines. Cardamonin is a spice component that exerts anti-inflammatory and anti-oxidative properties against pulmonary inflammation. Herein, the aim of this research is to investigate the effects of cardamonin on pulmonary inflammation and its mechanism. Pulmonary inflammation in mice was induced by intratracheal administration of PMA. PMA-stimulated acute fibrosis, pulmonary edema, and inflammatory responses were ameliorated by oral administration of cardamonin in vivo. In MH-S alveolar macrophages, PMA-induced pro-inflammatory responses, including iNOS, COX-2, MMP-9 and cytokines expressions were reduced by cardamonin. The anti-oxidative Nrf2/HO-1 axis was also provoked by cardamonin in MH-S alveolar macrophages. In addition, MMP-9 expression induced by PMA is also decreased by the down-stream metabolites of HO-1, indicating that HO-1 expression partially contributes to the anti-inflammatory effect exerted by cardamonin. In this study, cardamonin demonstrates anti-inflammatory and anti-oxidative effects on PMA-induced pulmonary inflammation and activating Nrf2/HO-1 axis in alveolar macrophages. Cardamonin also ameliorates pulmonary inflammation, rapid fibrosis in vivo, suggesting powerful health benefits.