Salidroside alleviates paraquat-induced rat acute lung injury by repressing TGF-β1 expression.

Objective: This study was designed to investigate the protective effects of salidroside (SDS) via suppressing the expression of transforming growth factor-β1 (TGF-β1) in rat acute lung injury (ALI) induced by paraquat (PQ) and to explore the potential molecular mechanisms.

Methods: A total of 90 male rats (190-210 g) were randomly and evenly divided into 9 groups: control group, PQ groups (4 groups), and PQ + SDS groups (4 groups). The rats in control group were treated with equal volume of saline intraperitoneally. The rats in PQ groups were exposed to PQ solution (20 mg/kg) by gastric gavage for 1, 6, 24, and 72 hours, respectively. The rats in PQ + SDS groups were intraperitoneally injected once with SDS (10 mg/kg) every 12 hours after PQ perfusion. Pulmonary pathological changes were observed by hematoxylin and eosin (HE) staining. The expression of TGF-β1 and the mRNA were evaluated by immunohistochemical (IHC) scoring and real time quantitative reverse transcription polymerase chain reaction (real-time qRT-PCR), respectively.

Results: SDS alleviated the symptoms of PQ induced ALI. Moreover, SDS reduced the expression of the inflammatory cytokine TGF-β1 including TGF-β1 IHC scores (at each time point from 6 to 72 hours after PQ perfusion) and mRNA level (at each time point from 1 to 72 hours after PQ perfusion) compared with PQ groups (P < 0.05).

Conclusion: SDS alleviated the pulmonary symptoms of PQ-induced ALI, at least partially, by repressing inflammatory cell infiltration and the expression of TGF-β1 resulting in delayed lung fibrosis.