Improvement of sepsis-related acute lung injury through Naringin by regulating TGF-β1/Smad2 signaling pathway / 国际中医中药杂志

ABSTRACT

Objective:To investigate the protective effect of naringenin on acute lung injury related with sepsis; To discuss its possible mechanism.Methods:Totally 30 male SD rats were randomly divided into sham-operation group, model group, naringin low-, medium- and high-dosage groups, with 6 rats in each group. The sepsis-related acute lung injury model was established by cecal ligation and puncture in all groups except the sham-operation group. After modeling, naringin low-, medium- and high-dosage groups were given naringin 20 mg/kg, 40 mg/kg and 80 mg/kg, respectively for gavage, while the sham-operation group and the model group were given the same volume of distilled water by gavage, once a day, for 2 days. Pathological changes in lung tissue were observed using HE staining. The levels of 1L-1, IL-6 and IL-18 in bronchoalveolar lavage fluid (BALF) were measured by ELISA; the expression of TNF-α in lung tissue was detected by immunofluorescence histopathology; the expressions of TGF-β1, TGF-βR1 and Smad2 were detected by Western Blot. An agonist group and a naringin plus agonist group were set up, with 6 mice in each group, and the expressions of TGF-β1 and Smad2 protein in the lung tissue of each group were detected by immunohistochemical staining to verify the effect of naringin on the expressions of TGF-β1 and Smad2 protein.Results:Compared with the model group, the pathological injury of lung tissue in naringin groups were obviously alleviated, and the levels of IL-1β, IL-6 and IL-18 in BALF decreased ( P<0.01), the protein expressions of TNF-α, TGF-β1, TGF-βR1 and Smad2 in lung tissue decreased ( P<0.01 or P<0.05). Further verification found that the expressions of TGF-β1 and Smad2 in the agonist group increased ( P<0.01), while the expressions of TGF-β1 and Smad2 in the naringin agonist group decreased ( P<0.01). Conclusion:Naringin can reduce the inflammatory response in the lung of the rats to protect against sepsis-related acute lung injury, and its protective effect could be related to the inhibition of the TGF-β1/Smad2 signaling pathway.