Objective: To explore the effect of Xuebijing plus methylprednisolone in a rat model of pulmonary fibrosis induced by bleomycin.
Methods: Eighty Wistar rats were randomly divided into 5 groups of control, model control, Xuebijing, methylprednisolone and combined treatment (Xuebijing plus methylprednisolone). Pulmonary fibrosis model was induced by an intra-tracheal injection of bleomycin. The treatment groups were administrated with 4.5 ml · kg(-1) · d(-1) Xuebijing and 4.5 ml · kg(-1) · d(-1) physiologic saline, 4.5 ml · kg(-1) · d(-1) methylprednisolone and 4.5 ml · kg(-1) · d(-1) physiologic saline, or 4.5 ml · kg(-1) · d(-1) methylprednisolone and 4.5 ml · kg(-1) · d(-1) Xuebijing respectively by intraperitoneal injection. And the control and model control groups received 9 ml · kg(-1) · d(-1) physiological saline. The animals were sacrificed at Days 14 and 28 respectively. The degrees of lung inflammation and pulmonary fibrosis were detected by hematoxylin & eosin and Masson staining. The serum levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were assessed by enzyme-linked immunosorbent assay (ELISA). The expression of transforming growth factor-β1 (TGF-β1) in lung tissue was evaluated by immunohistochemical staining.
Results: Compared between the combined treatment and model control groups, at Days 14 and 28, the degree of alveolitis ((1.09 ± 0.30) vs (2.03 ± 0.25) and (0.75 ± 0.27) vs (1.78 ± 0.36) ng/L) , the degree of pulmonary fibrosis ((0.91 ± 0.19 )vs (1.34 ± 0.23) and (0.75 ± 0.27) vs (1.78 ± 0.36)) . The expression of TGF-β1 in lung tissue ((12.11 ± 3.06)% vs (17.70 ± 2.70)% & (10.96 ± 2.53)% vs (16.72 ± 2.20)%). And the serum level of TNF-α ((68.39 ± 9.28) vs (90.94 ± 11.16) ng/L & (67.14 ± 10.88) vs (81.73 ± 7.23) ng/L) all significantly decreased (all P < 0.05). At Day 14, the serum level of IL-6 in the combined treatment group significantly decreased as compared with the model control group ((199 ± 31) vs (250 ± 43)ng/L, P = 0.036). At Day 28, no statistic difference was found ( (192 ± 25) vs (227 ± 24)ng/L, P = 0.058).
Conclusions: The combined treatment of methylprednisolone and Xuebijing is more effective in a rat model of pulmonary fibrosis. And its mechanism is associated with the reduced levels of IL-6 and TNF-α and TGF-β1 expression in lung tissue.