Tetrahydrocoptisine Protects Rats from LPS-Induced Acute Lung Injury

Recent studies show that nuclear factor-kappa B (NF-κB) signaling pathway plays a key role in contributing to the development of lipopolysaccharide (LPS)-induced acute lung injury (ALI). Tetrahydrocoptisine is one of the main active components of Chelidonium majus L. and has been described to be effective in suppressing inflammation. The aim of the present study is to evaluate the protective effect of tetrahydrocoptisine on LPS-induced ALI in rats and clarify its underlying mechanisms of action. We found that in vivo pretreatment with tetrahydrocoptisine to rats 30 min before inducing ALI by LPS markedly decreased the mortality rate, lung wet weight to dry weight ratio, and ameliorated lung pathological changes. Meanwhile, tetrahydrocoptisine significantly inhibited the increase of the amounts of inflammatory cells, total protein content, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) secretion in the bronchoalveolar lavage fluids (BALFs). Furthermore, tetrahydrocoptisine inhibited myeloperoxidase (MPO) accumulation in lung tissue and alleviated TNF-α and IL-6 production in serum. Additionally, immunohistochemistry showed that tetrahydrocoptisine efficiently reduced nuclear factor-kappa B (NF-κB) activation by inhibiting the translocation of NF-κBp65. In conclusion, our results demonstrate that tetrahydrocoptisine possesses a protective effect on LPS-induced ALI through inhibiting of NF-κB signaling pathways, which may involve the inhibition of pulmonary inflammatory process.