Basic Study on Inhibitory Effect of Sulforaphane on Inflammatory Response and Alleviation of Airway Remodeling in COPD Rats / 广州中医药大学学报

ABSTRACT

Objective To investigate the ameliorative effect of sulforaphane on inflammatory response and airway remodeling in rats with chronic obstructive pulmonary disease(COPD).Methods Seventy-five SD rats were randomly divided into the normal group,the model group,and the low-,medium-,and high-dose groups of sulforaphane,with 15 rats in each group.Except for the normal group,the COPD model was prepared in the remaining group using aroma smoke inhalation combined with intratracheal droplet lipopolysaccharide(LPS)method.After the successful modelling,the rats were administered the drug by gavage for 28 days.At the end of the administration,the general conditions of the rats in each group were observed,and the lung function[forced vital capacity(FVC),peak expiratory flow-rate(PEF),forceful expiratory volume in 1 second(FEV1)]was examined,and the pathological changes of the lung tissues were observed by hematoxylin-eosin(HE)staining method,and the indexes of airway remodeling(thickness of the bronchial wall,thickness of the smooth muscle)were measured;the enzyme-linked immunosorbent assay(ELISA)was used to examine the lung function of the rats.The levels of inflammatory factors[tumor necrosis factor α(TNF-α),interleukin 1β(IL-1β)]were detected in lung tissue by enzyme-linked immunosorbent assay(ELISA),and changes in the protein expressions of Toll-like receptor 4(TLR4),myeloid differentiation factor 88(MyD88),and nuclear transcription factor κB(NF-κB)were detected in lung tissue by Western Blot.Results(1)The rats in the model group had dry and lack of glossy fur,obvious coughing and nose scratching,shortness of breath,slow movement,and preferred to arch their backs and lie curled up;the rats in the low-,medium-and high-dose groups of sulforaphane showed significant improvement in shortness of breath,coughing,and other abnormal manifestations.(2)HE staining showed that the airway wall and smooth muscle of rats in the model group were thickened,the airway epithelium was damaged,and alveolar destruction,fusion,and massive infiltration of inflammatory cells were seen;the histopathological changes in the lungs of rats in the low-,medium-and high-dose groups of sulforaphane improved to varying degrees,with the airway wall becoming thinner,the degree of alveolar destruction being reduced,and the infiltration of inflammatory cells being reduced.(3)Compared with the normal group,FVC,PEF and FEV1 were significantly reduced in the model group(P＜0.05),and the levels of TNF-α and IL-1β,bronchial wall thickness,smooth muscle thickness,and the expression levels of TLR4,MyD88 and NF-κB were significantly increased in the model group(P＜0.05);and in comparison with the model group,the levels of FVC,PEF,and FEV1 were significantly increased in the rats in the sulforaphane low-,medium-,and high-dose groups(P＜0.05),and the levels of TNF-α,IL-1β,bronchial wall thickness,smooth muscle thickness,and the expression levels of TLR4,MyD88,and NF-κB were significantly decreased(P＜0.05)compared with the model group.Conclusion Sulforaphane helps to inhibit the inflammatory response,attenuate airway remodeling,and improve the pathological injury and lung function of lung tissue in rats with COPD,and its mechanism may be related to the inhibition of TLR4,MyD88,and NF-κB protein expressions.