Shenmai injection alleviates acute lung injury in a severe acute pancreatitis rat model via heme oxygenase-1 upregulation

Background: To determine the effect of Shenmai injection (SMI) on acute lung injury (ALI) induced by severe acute pancreatitis (SAP) in rats. Methods: Forty male Sprague-Dawley (SD) rats were grouped into 4 categories: SAP group, sham surgery (SS) group, SAP + SMI group, SAP + SMI + Zinc protoporphyrin (ZnPP) group. Rats in the SAP group were intravenously injected with 1.6 ml/kg saline 30 minutes after induction of SAP models. Rats in the SAP + SMI group were intravenously injected with 1.6 ml/kg SMI, while those in the SAP + SMI + ZnPP group rats were intravenously injected with 1.6 ml/kg SMI and 30 mg/kg ZnPP via intraperitoneal injection. Twenty-four hours after SAP induction, the rats were sacrificed. Excised lung tissues were histologically examined, protein concentration in bronchoalvelar lavage fluid (BALF) was measured and lung wet-to-dry (W/D) weight ratio was calculated. The protein and mRNA levels of the tumor necrosis factor (TNF) -α, heme oxygenase (HO) -1 and interleukin (IL) -10 in blood and tissue samples were measured.Results: SMI treatment attenuated SAP-induced ALI as evidenced by lower scores of lung damage compared with untreated SAP group (p＜0.05). SMI also abolished the SAP-induced rise in BALF and W/D ratio protein concentrations (p＜0.05). Moreover, SMI treatment increased HO-1, IL-10 levels but decreased TNF-α level in serum and tissue samples (p＜0.05). However, inhibition of HO-1 expression by ZnPP led to significant inhibition of all the changes.Conclusions: SMI can alleviate SAP-induced ALI through HO-1 upregulation.