Effects Of Andrographolide On Bleomycin-Induced Rat Pulmonary Fibrosis

Objective:To investigate the effects of andrograph-olide on bleomycin (BLM)-induced pulmonary fibrosis in Rats. Methods:90 healthy SD male rats were randomly divided into 6 groups on average. They were normal saline (NS) group, BLM group, prednisone (Pred) group and different doses of androgr-apholide groups (andrographolide A group 62.5mg/kg, andrograp-holide B group 125mg/kg and andrographolide C group 250mg/kg). Intratracheal instillation of BLM was given to BLM group, Pred group and andrographolide A, B, C group, and NS was given to NS group through intratracheal. And then NS (NS group, BLM group), Pred (Pred group) or andrographolide (andrograoholide A, B, C group) was given to rats by gavage every day. Five rats of each group were killed respectively at day 7,14,28 after intratracheal instillation. Alveolitis and fibrosis were observed by HE and Masson staining. Real-time fluorescent quantitative reverse transcription-polymerase chain reaction (FQ RT-PCR) was performed to detect collagen I and III mRNA expression in lung tissue, and the concentration of TNF-αand TGF-β1 in bronchoalveolar lavage fluid (BALF) was determined by enzyme-linked immunosorbnent assay. Blood urea nitrogen (BUN), creatinine (Cr) and alanine aminotransferase (ALT), aspartate aminotransferase (AST) were also examined. Results:(1) The comparison of AST,ALT,BUN,Cr in different doses of group andrographolide, NS group, BLM group and Pred group had no statistical significance. (2) Alveolar septal edema, inflammatory cell infiltration and fibrosis were not found in NS group. A great deal of inflammatory cells infiltration into the alveolar were observed in BLM group at day 7. The alveolitis was still heavy at day 14, but inflammatory cells were significantly reduced, and the number of the fibroblasts and matrix in alveolar septum were obviously increased. At the same time, alveolar structure was damaged and alveolar septum widened; the inflammation relieved, pulmonary fibrosis increased, parts of alveolar space was disappeared and severe fibrosis was found at day 28. It was similar in pathomorphology between andrographolide A group and BLM group. A lot of inflammatory cells infiltration and local accumulation were observed at day 7 in group andrographolide B, C and Pred. Lung tissue edema was not obvious, and the pathological change of fibrosis at day 14,28 was more significantly reduced than group andrographolide A and BLM. (3) The concentration of TGF-β1,TNF-αin BALF of NS group at each time point was significantly lower than group Pred, BLM, andrographolide A, B, C at the same time point, and the difference had statistical significance (P<0.05). The concentration of TGF-β1 and TNF-a in BALF of BLM group at day 7,14,28 was higher than Pred group, andrographolide B group and andrographolide C group, and the difference had statistical significance (P<0.05). Compared with BLM group, the concentration of TGF-β1 and TNF-αin BALF of andrographolide A group had no statistical significance. (4) The expression of collagenⅠandⅢmRNA in lung tissue of NS group at each time point was significantly lower than group Pred, BLM, andrographolide A, B, C at the same time point, and the difference had statistical significance (P<0.05). The expression of collgen I and III mRNA in lung tissue of BLM group at day 7,14,28 was higher than Pred group, andrographolide B group, and andrographolide C group, and the difference had statistical significance (P<0.05). Compared with BLM group, the expression of collagen I and III mRNA in lung tissue of andrographolide A group had no statistical significance. Conclusion:In bleomycin-induced rat pulmonary fibrosis, a certain dosage of andrographolide could attenuate alveolitis and fibrosis, decrease mRNA expression of collagen I and III in lung tissue and decrease the concentration of TNF-αand TGF-β1 in BALF. It had no side effects on liver and kidney function.