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In drowning victims, acute respiratory failure and hypoxia are very common, 1) and hypoxia-induced organ damage due to pulmonary edema caused by aspiration of water has been recognized as a major cause of death in near-drowning victims. [2][3][4] But the exact mechanisms remain unclear. Previous clinical studies have shown that white blood cell and neutrophils apparently increased in most acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) drowning patients' plasma with bilateral diffuse or localized alveolar infiltrates on chest X-ray obtained shortly after arrival. 5) In seawater aspiration-induced ALI rabbits model, the infiltration of inflammatory cells are increased in alveolar spaces with evidence of increasing of myeloperoxidase (MPO) activity and tumor necrosis factor-a (TNF-a) concentration in lung tissue. 6) These results may provide a potential mechanism that inflammation could partly explain the lung injury following seawater aspiration.Danshen, a traditional medical ingredient herbal drug deriving from dried roots of Salvia miltiorrhiza BUNGE, has been widely used in the treatment of acute or chronic diseases as circulatory, cerebrovascular disorders. 7) Tanshinone IIA (TIIA), one of the major active components of Danshen, has been reported to protect against lipopolysaccharide (LPS)-induced lung injury in mice.8) It is also shown that TIIA has an anti-inflammatory effect through the inhibition of nuclear factor-kB (NF-kB) activity 9) and the expression of inflammatory mediators such as nitric oxide, TNF-a, interleukin-1 (IL-1) and interleukin-6 (IL-6) in macrophage cells.10) Whether TIIA plays a protective effect on lung injury following seawater aspiration is unknown.Macrophage migration inhibitory factor (MIF) is recognized as a proinflammatory cytokine which derived from many cell types including macrophages and T lymphocytes.11) It is reported that serum MIF levels are significantly increased in ALI patients or animal model compared to healthy controls, as revealed MIF is a putative biomarker in ALI.12) Additionally, after activating NF-kB, MIF can induce the production of subsequent cytokines.13) The selective inhibition of inflammatory cytokine activities may remain an important goal for the effective treatment of acute lung injury.In the present study, we reported that TIIA treatment significantly attenuated seawater aspiration-induced lung injury. It was probably associated with downregulation of MIF and the subsequent inhibition of NF-kB activity as well as expression of IL-6 and TNF-a. MATERIALS AND METHODSChemicals Tanshinone IIA (sulfonate, purity is 99%) was purchased from the National Institute for the Control of Pharmaceutical and Biological Products (NICPBP, Beijing, China). The kits for determination of myeloperoxidase activity were obtained from Jiancheng Bioengineering Institute (Nanjing, China). Anti-phospho-NF-kB p65 and anti-b-actin monoclonal antibodies were obtained from Santa Cruz Biotechnology Inc. (Santa Cruz, CA, U.S.A.). Anti-MIF monoclonal antibody was g...

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1. Tanshinone IIA (TIIA) is one of the main active components of the Chinese herb, Danshen. In the present study, we investigated the role of apoptosis in seawater exposure-induced acute lung injury (ALI), and explored the effects of TIIA on lung injury, apoptosis, and protein kinase B (Akt) and extracellular signal-regulated protein kinase (ERK) pathways in seawater-challenged rats. The rats were randomly divided into four groups: (i) naive group, no drug was given; (ii) TIIA control group, TIIA (50 mg/kg) was given intraperitoneally; (iii) seawater (SW) group, seawater (4 mL/kg) was given; and (iv) TIIA/SW group, TIIA (50 mg/kg) was injected intraperitoneally 10 min after seawater instillation. 2. The results showed that TIIA treatment significantly improved seawater exposure-induced lung histopathological changes, alleviated the decrease in PaO(2) , and reduced lung oedema, vascular leakage and cell infiltration. As shown by terminal deoxynucleotidyl transferase-mediated nick end labelling (TUNEL) assay, seawater exposure induced apoptosis in lung tissue cells. Furthermore, seawater exposure also changed apoptosis-related factors Bcl-2 and caspase-3, and caused a reduction in the activation of Akt and ERK1/2 pathways. Furthermore, TIIA treatment decreased the number of apoptotic cells, reversed changes in Bcl-2 and caspase-3, and upregulated the activation of Akt and ERK1/2 in seawater-challenged rats. 3. In conclusion, the data suggest that apoptosis might play an important role in seawater exposure-induced lung injury and that TIIA could significantly attenuate the severity of ALI and apoptosis in seawater-challenged rats, which is possibly through modulation of Akt and ERK1/2 pathways.