Therapeutic Effect And Mechanism Of Resveratrol In Rats With Chronic Obstructive Pulmonary Disease

Objective: This study aims to observe the effect of resveratrol(Res)on lung function and pathology,and cardiac structure and function of rats with smoke-induced chronic obstructive pulmonary disease(COPD)lung function;to investigate the effect of resveratrol on the expression of inflammatory cytokines,IL-32?IL-18 and TNF-?,matrix metalloproteinases(MMP-2 and MMP-12),tissue inhibitor of metalloproteinase,TIMP-1,and apoptosis factors,Casepase-1 and Casepase-8,in lung tissue of rats with COPD;and to discuss the therapeutic value of resveratrol in COPD by inhibiting inflammation,MMP/TIMPS imbalance,and apoptosis.Methods:1 COPD was induced by smoke.Forty male SD rats were randomly divided into four groups: control group,smoking group,budesonide group,and resveratrol group Except for the control group,all rats in each group were exposed to 20 cigarettes for one hour each time,twice daily at intervals of five hours for four months.The resveratrol group was gavaged with resveratrol(30 mg/kg/d)once daily prior to smoke exposure from the day of smoke exposure.The budesonide group received nebulized budesonide(2 mg/rat)once daily in the last month.After four months,the body weight of rats was measured,total and differential leukocyte counts in bronchoalveolar lavage fluid(BALF)were determined,lung histopathology was observed,and right ventricular hypertrophy index and cardiac function were measured.2 The protein expression of TNF-?? IL-18? IL-32?MMP-2?MMP-12?caspase-1and caspase-8 in lung tissue of rats was measured by immunohistochemistry and western blotting,respectively.The mRNA expression of TNF-??IL-18?IL-32?MMP-2?MMP-12?caspase-1and caspase-8 in lung tissue of rats was determined by real-time PCR.Results:1 General condition of ratsBefore the experiment,no significant difference was noted in smoothness and shininess of hair,activity,and responsiveness to external stimuli among four groups of rats.After the experiment,rats in the control group had smooth,shiny hair,and was active and properly responsive to external stimuli.Rats in the smoking group were slow,ponderous,and quiet,had a reduced food intake,coarse,dry hair,yellow teeth,and decreased responsiveness to external stimuli.Compared with the smoking group,the resveratrol and budesonide groups were more active,and had a relatively normal food intake.There was no significant difference between the resveratrol and budesonide groups.2 Measurement of body weightThere was no significant difference in body weight among the four groups(P>0.05).At the end of the experiment,the smoking group had a significantly decreased body weight compared with the control group(P< 0.01);and compared with the smoking group,the budesonide group and the resveratrol group had a significantly increased body weight(P<0.01,P<0.05).Although weight gain in the resveratrol group was not as significant as that in the budesonide group,no significant difference was noted between the two groups(P>0.05).3 Measurement of lung function in ratsFEV0.2 was significantly lower in the smoking group than in the control group(P<0.01);compared with the smoking group,FEV0.2 was increased in the resveratrol and budesonide groups(both P<0.05);the increase in the resveratrol group was not as significant as that in the budesonide group(P>0.05).FVC was significantly higher in the smoking group than in the control group(P<0.01);compared with the smoking group,FVC was significantly decreased in the resveratrol and budesonide groups(both P<0.01);the decrease in the resveratrol group was not as significant as that in the budesonide group(P>0.05).FEV0.2/FVC was significantly lower in the smoking group than in the control group(P<0.01);compared with the smoking group,FEV0.2/FVC was increased in the resveratrol and budesonide groups(both P<0.05);the increase in the resveratrol group was not as significant as that in the budesonide group(P>0.05).4 Observation of pathological changesIn the control group,the lungs appeared to be smooth and elastic,ruddy in color,and even in texture;and intact and continuous tracheal wall,with a clear structure and regularly arranged epithelial cilia,was observed under a microscope.Compared with the control group,the lungs appeared to be larger,pale,poorly elastic,and uneven in texture in the smoking group;trachea with small lumens,thick walls,and lodging,disordered,and missing epithelial cilia were observed under a microscope;infiltration of neutrophils,monocytes and lymphocytes was observed around the walls of bronchioles and small bronchi;and alveoli were enlarged,alveolar walls were thinned,some alveoli fused,and emphysema was developed.Compared with the smoking group,the lungs appeared to be slightly smaller in the resveratrol group;alveoli were still enlarged;some alveoli fused,but at a relatively more limited level;infiltration of inflammatory cells around the bronchial wall was reduced;hyperplasia of airway smooth muscle was mild;and cilia lodging and tracheal mucosal exfoliation were alleviated.Compared with the smoking group,the lungs appeared to be slightly smaller,more elastic,and more even in texture in the budesonide group;alveoli were still enlarged,but to a smaller degree;infiltration of neutrophils,monocytes and other inflammatory cells around the bronchial wall was obviously reduced;cilia lodging and depletion were alleviated.Overall,slightly better results were observed in the budesonide group than in the resveratrol group.MAN was significantly lower in the smoking group compared with the control group;it was significantly increased in the resveratrol and budesonide groups compared with the smoking group(both P<0.01);the increase was more significant in the resveratrol group than in the budesonide group(P>0.05).MLI was significantly lower in the smoking group than in the control group;compared with the smoking group,it was increased in the budesonide group(P<0.05)and significantly increased in the resveratrol group(P<0.01);the increase was more significant in the resveratrol group than in the budesonide group(P> 0.05).BWT/D was significantly higher in the smoking group than in the control group;it was significantly decreased in the resveratrol and budesonide groups compared with the smoking group(both P<0.01);BWT/D was lower in the resveratrol group than in the budesonide group(P>0.05).5 EchocardiographyLVEF was significantly lower in the smoking group compared with the control group(P<0.01);compared with the smoking group,it was significantly increased in the budesonide group(P<0.01)and increased in the resveratrol group(P<0.05);and it was significantly lower in the resveratrol group than in the budesonide group(P<0.01).mPAP was significantly higher in the smoking group than in the control group(P<0.01);compared with the smoking group,it was significantly decreased in the resveratrol and budesonide groups(both P < 0.01);and it was lower(P>0.05).RVAWd was significantly higher in the smoking group than in the control group(P<0.01);compared with the smoking group,it was significantly decreased in the resveratrol and budesonide groups(both P<0.01);and it was significantly lower in the resveratrol group than in the budesonide group(P<0.01).There was no significant difference in LVPWd and LVAWd among the four groups(bothP>0.05).6 Right ventricular hypertrophy indexThe right ventricle was enlarged in the smoking group,with a significant increase in right ventricular hypertrophy index compared with the control group(P<0.01).Compared with the smoking group,the right ventricular hypertrophy index was decreased in the resveratrol and budesonide groups(both P <0.05).The decrease was more significant in the resveratrol group than in the budesonide group,but there was no significant difference between the two groups(P>0.05).7 Total and differential BALF leukocyte countsTotal leukocyte count was significantly higher in the smoking group than in the control group(P<0.01);compared with the smoking group,it was significantly decreased in the resveratrol and budesonide groups(both P< 0.01);and it was significantly lower in the budesonide group than in the resveratrol group(P<0.01).Neutrophil count was significantly higher in the smoking group than in the control group(P<0.01);compared with the smoking group,it was significantly decreased in the resveratrol and budesonide groups(both P<0.01);and it was significantly lower in the budesonide group than in the resveratrol group(P<0.01).Monocyte count was significantly higher in the smoking group than in the control group(P<0.01);compared with the smoking group,it was significantly decreased in the resveratrol group(P<0.01),but it was not significantly different from the budesonide group(P>0.05);and it was significantly higher in the budesonide group than in the resveratrol group(P<0.01).Lymphocyte count was significantly lower in the smoking group than in the control group(P<0.05);compared with the smoking group,it was significantly increased in the resveratrol and budesonide groups(both P<0.01);the increase was more significant in the resveratrol group than in the budesonide group(P>0.05).5 Comparison of protein expression of TNF-?,IL-18,IL-32,MMP-2,MMP-12,TIMP-1,caspase-1and caspase-8 in the alveolar wall and the membrane and cytoplasm of bronchial epithelial cells by immunohisto-chemitryCompared with the control group,the expression of TNF-?,IL-18,IL-32,MMP-2,MMP-12,caspase-1and caspase-8 was increased in the smoking group,and that of TIMP-1 was decreased.Compared with the smoking group,the expression of TNF-?,IL-18,IL-32,MMP-2,MMP-12,caspase-1and caspase-8 was decreased in the resveratrol and budesonide groups,and that of TIMP-1 was increased.Compared with the smoking group,TIMP-1 protein expression was increased in the resveratrol and budesonide groups.Compared with the budesonide group,the expression of caspase-1 and caspase-8 was increased in the resveratrol group.6 Comparison of protein expression of TNF-?,IL-18,IL-32,MMP-2,MMP-12,TIMP-1,caspase-1and caspase-8by western blottingCompared with the control group,the expression of TNF-?,IL-18,IL-32,MMP-2,MMP-12,caspase-1,and caspase-8 was increased in the smoking group,and that of TIMP-1 was decreased.Compared with the smoking group,the expression of TNF-?,IL-18,IL-32,MMP-2,MMP-12,caspase-1,and caspase-8 was decreased in the resveratrol and budesonide groups,and that of TIMP-1 was increased.Compared with the smoking group,TIMP-1 protein expression was increased in the resveratrol and budesonide groups.Compared with the budesonide group,the expression of caspase-1 and caspase-8 was increased in the resveratrol group.7 Comparison of RNA expression of TNF-?? IL-18,IL-32,MMP-2,MMP-12,TIMP-1,caspase-1and caspase-8 by RT-PCRCompared with the Control group,the expression of TNF-?,IL-18,IL-32,MMP-2,MMP-12,caspase-1,andcaspase-8 increased significantly than Smoking(P<0.01),TIMP-1 decreased significantly(P<0.01).Compared with the smoking group,resveratrol group and budesonide group TNF-?,IL-18,MMP-2,IL-32,MMP-12 and caspase-1 expression decreased significantly(P <0.01),TIMP-1 and caspase-8 expression was elevated(respectively P<0.05,P<0.01);resveratrol group compared with budesonide group TNF-?,MMP-2 decreased(P < 0.05),IL-18,MMP-12,caspase-1,Caspase-8 decreased significantly(P < 0.01),TIMP-1 increased significantly(P < 0.01)IL-32 no change(P > 0.05).Conclusions:1 Cigarette smoke-induced COPD was successfully developed in rats in the four-month experiment.After administration of resveratrol,leukocyte and neutrophil counts were decreased in the walls of bronchioles and small bronchi and alveoli in rats with COPD,and lung function was improved significantly,representing no significant difference from the budesonide group.Right ventricular structure and function were improved significantly,and the resveratrol group was slightly better than the budesonide group.2 TNF-?,IL-18,IL-32,MMP-2,MMP-12,TIMP-1,caspase-1and caspase-8play an important role in the pathogenesis and development of COPD.Resveratrol treatment may be an effective treatment of COPD by reducing pulmonary inflammation,improving the protease-antiprotease imbalance,and inhibiting apoptosis.