Protective effect of total alkaloids on lipopolysaccharide-induced acute lung injury

Background: Corydalis denticulato-bracteata Fedde is used as a traditional herbal medicine for the treatment of pneumonia. However, there is no scientific evidence, which validate the use of total alkaloids of denticulato-bracteata Fedde in the literature. Materials and methods: Male Kunming mice were randomly divided into seven groups (n = 12, each): control group, total alkaloids alone (200 mg/kg, intragastric gavage), LPS group, and three different doses (50, 100, and 200 mg/kg, intragastric gavage) for total alkaloids-treated groups, Dexamethasone (5 mg/kg, intraperitoneally) group. Corresponding drugs or vehicles were given 24 and 1 h before lipopolysaccharide (LPS) administration (5 mg/kg, intraperitoneally). The severity of pulmonary injury was evaluated 6 h after LPS challenge. Results: As revealed by survival study, pretreatment with total alkaloids significantly reduced LPS-induced death. We also found that total alkaloids pretreatment markedly decreased the lung wet-to-dry weight ratios and significantly attenuated histopathologic changes. Moreover, total alkaloids decreased the production of the tumor necrosis factor α and nitric oxide in the serum and bronchoalveolar lavage fluid. Total alkaloids pretreatment also reduced LPS-induced inducible nitric oxide synthase and p65 nuclear factor kappa B protein expression in the lung. Conclusions: This study indicates that total alkaloids may have a protective effect against LPS-induced acute lung injury. This protective effect of total alkaloids seems to result from inhibition of nuclear factor kappa B activation, which causes the reduction of inflammatory markers such as tumor necrosis factor α and inducible nitric oxide synthase.