The therapeutic efficacy of Ulinastatin for rats with smoking inhalation injury

Smoke inhalation injury represents a major cause of mortality in burn patients and is associated with a high incidence of pulmonary complications. Ulinastatin (UTI) has been widely used as a drug for patients with severe burn, sepsis, severe acute pancreatitis, and multiple organ dysfunction syndrome. In view of the critical role of inflammatory response in pathogenesis of smoke inhalation-induced lung injury and the anti-inflammatory effects of UTI, we hypothesized that treatment with UTI could lessen smoke inhalation-induced lung injury. In this study, fifty-four rats were equally randomized to three groups: Sham group (ambient air inhalation), Control group (smoke inhalation injury) and UTI treatment group (UTI treatment plus smoke inhalation injury). At sampling, bronchoalveolar lavage fluid was performed to determine total protein concentration and pro-inflammatory cytokine levels. Lung tissues were collected for the measurement of wet/dry ratio, myeloperoxidase, histopathology, hydroxyproline, collagens I and III, and western blotting. Our present work exhibited that UTI attenuated the lung histopathological alterations, improved the pulmonary function, inhibited neutrophil accumulation and mitigated pulmonary edema. In addition, UTI mitigated the inflammatory response, and further prevented the initiation of downstream inflammatory cascades: NF-κB and p-JNK. Importantly, UTI also mitigated smoke inhalation-induced pulmonary fibrosis as evidenced by Masson–Goldner trichrome staining with the content of hydroxyproline and collagens I and III. In conclusion, our data demonstrated that UTI protected rat against smoke inhalation-induced acute lung injury and the subsequent development of pulmonary fibrosis.

► Ulinastatin ameliorated the smoke inhalation-induced lung injury.
► Ulinastatin inhibited smoke inhalation-induced over-activity of p-JNK and NF-κB.
► Ulinastatin lessened the smoke inhalation-induced pulmonary fibrosis formation.