Tubeimoside I attenuates inflammation and oxidative damage in a mice model of PM2.5‑induced pulmonary injury

In the present study, the effects of tubeimoside I (TBMS1) on particulate matter <2.5 µm in diameter (PM2.5)‑induced pulmonary injury and its mechanisms of action were investigated. Male BALB/c mice were randomly assigned into five groups (n=10/group): Control, PM2.5, PM2.5 + TBMS1 45 mg/kg, PM2.5 + TBMS1 90 mg/kg and PM2.5 + TBMS1 180 mg/kg. The dose of the PM2.5 suspension administered to the mice was 40 mg/kg via nasal instillation. The PM2.5 + TBMS1 groups received TBMS1 daily orally for 21 consecutive days, while the mice in the control and PM2.5 groups received equivalent volumes of PBS. Subsequently, lactic dehydrogenase, acid phosphatase, alkaline phosphatase, albumin, tumor necrosis factor‑α and interleukin‑6 protein levels in bronchoalveolar lavage fluid were determined. Oxidative stress was evaluated by detecting the protein levels of malondialdehyde, superoxide dismutase and inducible nitric oxide synthase, and the level of nitric oxide in lung tissue. Lastly, histopathological images of lung sections were obtained to observe changes in the lung tissue with treatment. The results indicated that exposure to PM2.5 induced pathological pulmonary changes, and biofilm and parenchymal cell damage, and promoted inflammation and oxidative stress. Treatment with TBMS1 attenuated the development of PM2.5‑induced pulmonary injury. Its mechanisms of action were associated with reducing cytotoxic effects, levels of inflammatory mediators and oxidative damage. In conclusion, the results of the present study indicate that TBMS1 is a potential therapeutic drug for treating PM2.5‑induced pulmonary injury.