The Effects Of Andrographolide On The Expression Of PDGF And Hydroxyproline In Lung Tissue In Rat Pulmonary Fibrosis

Objective:To investigate the effect of andrographolide on the expression of PDGF and hydroxyproline in lung tissue in rat pulmonary fibrosis.Methods:Ninety adult male SD rats were randomly divided into six groups on average. They were normal saline (NS) group,pingyangmycin(PYM) group,prednisone(PNS) group and different doses of andrographolide groups(AND A group 62.5mg/kg,AND B group 125mg/kg and AND C group 250mg/kg),and each group had fifteen rats. Intratracheal instillation of PYM was given to PYM group, PNS group and AND A, B, C group, while NS group with 0.9% NaCl solution. A day later, NS(NS group and PYM group),PNS(PNS group) and andrographolide(AND A, B, C group) were administrated on rats by gavage on time every day.Each group was again divided into 3 subgroups on average,which were sacrificed at day 7,14 and 28. Blood urea nitrogen (BUN),creatinine (Cr) and alanine aminotransferase (ALT),aspartate aminotransferase (AST) were examined; The lung tissue of rats HE and Masson staining were performed to observe the extent of alveolitis and fibrosis; Platelet derived growth factor (PDGF) protein in lung tissue was assessed by immunohistochemistry; Hydroxyproline content was also detected. Results: (1)Compared with NS group, there was no statistical difference in the concentration of BUN,Cr,ALT,AST in serum of rats in the other groups (P> 0.05); (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 PYM 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 AND A group and PYM group. A lot of inflammatory cells infiltration and local accumulation were observed at day 7 in group AND B, C and PNS. The pathological change of fibrosis at day 14,28 was more significantly reduced than group AND A and PYM. (3) The expression of PDGF protein in NS group was low,while the other groups were obviously high(P<0.05); Compared with PYM group, the expression of PDGF in PNS group and andrographolide groups was lower at day 7,14,28 (P<0.05); Compared with PNS group and AND A group,the expression of PDGF in AND B group and AND C group was lower at day 7,14 (P<0.05). (4)The content of hydroxyproline of lung tissue in NS group was low, while the other groups were obviously high (P<0.05); Compared with PYM group, the content of hydroxyproline in PNS group and all andrographolide groups was lower at day 7,14,28(P<0.05); Compared with PNS group, the content of hydroxyproline in AND B and C groups were lower at day 7,14 (P<0.05). Conclusion:A certain dose of andrographolide could abate the alveolitis,decrease the level of PDGF protein and hydroxyproline in lung tissue, ameliorate the extent of pulmonary fibrosis,and there was no toxic side effect of liver and kidney in pingyangmycin-induced rat pulmonary fibrosis.