Effects Of Grape Seed Procyanidins On Pulmonary Fibrosis Rats Induced By Bleomycin

Objective To study the effects of grape seed procyanidins( GSP) on pulmonary fibrosis induced by bleomycin(BLM) in rats and its mechanism.Methods Forty-five SD male rats were divided into normal group(group N, n=15), model group(group M, n=15) and GSP group(group G,n=15). BLM and physiological saline mix solution0.25mL(5mg?kg-1) was intratracheally instilled to the rats in the group M and group G to set up the model of pulmonary fibrosis, and the same volume of physiological saline was given to the rats in the group N. Two days after the surgery, the rats in the group G were fed with GSP and physiological saline mix solution0.1ml?10g-1(500mg?kg-1) daily, and the rats in the group N and group M were fed with physiological saline 0.1ml?10g-1daily. At the 7th, 14 th and28th day after administration, five rats of each group were sacrificed and the lung tissue was collected. Some lung tissue was used for pathological examination and hydroxyproline(HYP) of lung tissue homogenate was determined. The expression of vascular endothelial growth factors(VEGF)and vascular endothelial cell growth factor receptor 1(VEGFR1) mRNAlevels was determined by RT-qPCR. VEGF and VEGFR1 protein was analyzed by Western blot.Results At each time point, Ashcroft score in the group M was higher than that in the group N(P<0.01)and group G(P<0.05). Lung tissue of rats in the group N had no obvious pathological changes, while that in the group M appeared severe alveolar inflammation and lung fibrosis.Compared with that in the group M, alveolar inflammation and fibrosis of lung tissue of rats in the group G reduced significantly at each observation point. HYP content, expression of VEGF and VEGFR1 protein and mRNA levels in lung tissue of rats in the group M were obviously higher than those in the group N( P<0.01) at each observation point. HYP content,VEGF protein and mRNA levels in the group G were lower than those in the group M(P<0.05 or P<0.01). At the 7th, 14 th day after administration,VEGFR1 protein and mRNA levels of lung tissue in the group G were lower than those in the group M(P<0.05), and with no statistic difference between two groups at 28 th day(P>0.05).Conclusion GSP can inhibit pulmonary fibrosis, and reducing the expression of VEGF and VEGFR1 protein and mRNA levels in lung tissue may be one of its mechanisms.