Modified Wuhutang Alleviates Airway Inflammation and Down-regulates Expression of Muc5AC， STAT3， NF-κB， and NLRP3 in Lung Tissues of RSV-infected Asthmatic Mice / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore effect of modified Wuhutang on airway inflammation and expression of mucin （Muc） 5AC， signal transducer and activator of transcription 3 （STAT3）， nuclear factor kappa B （NF-κB）， and NOD-like receptor thermal protein domain associated protein 3 （NLRP3） in respiratory syncytial virus （RSV）-infected asthmatic mice. MethodSeventy male BALB/c mice of 6-8 weeks old were randomized into normal control （CON）， asthma （ovalbumin， OVA）， RSV infection-induced asthma （OVA+RSV）， high-， medium-， and low-dose （4.08， 2.04， 1.02 g·kg-1·d-1， respectively） modified Wuhutang， and dexamethasone （Dxms， 0.1 g·kg-1d-1） groups （n=10）. The model of asthma was established by sensitization and atomization inhalation with OVA. The RSV infection-induced asthma model was established by three consecutive RSV nasal infusions （1.0 × 106 PFU·mL-1， 50 μL）. Wuhutang was administrated by gavage， and Dxms by intraperitoneal injection. The CON group was given the same amount of normal saline by gavage. The mice were anesthetized with 2.5% pentobarbital sodium 24 h after the last administration， and then the lung tissue was stained by hematoxylin-eosin （HE） and Van Gieson （VG） for observation of airway inflammation. The immunohistochemical assay was employed to detect the expression of Muc5AC. Western blot was employed to determine the protein levels of phosphorylated （p）-STAT3， STAT3， p-NF-κB， NF-κB， and NLRP3. ResultCompared with the CON group， the OVA group presented airway inflammatory cell infiltration， tissue hyperemia and edema， and collagen fiber deposition. The OVA+RSV group showed severer airway inflammatory cell infiltration and tissue hyperemia and edema than the OVA group. Compared with the OVA+RSV group， modified Wuhutang alleviated the airway inflammatory cell infiltration， tissue hyperemia and edema， and collagen fiber deposition， and the high-dose group had the best performance. Compared with the CON group， the OVA group and the OVA+RSV group showed increased expression level of Muc5AC （P<0.01）. Compared with the OVA+RSV group， modified Wuhutang reduced the expression level of Muc5AC， and the reduction was significant in the high-dose group （P<0.05）. Compared with the high-dose modified Wuhutang group， Dxms lowered the expression level of Muc5AC （P<0.05）. Compared with the CON group， the OVA and OVA+RSV groups showed up-regulated protein levels of p-STAT3， p-NF-κB， and NLRP3 （P<0.05， P<0.01）. Compared with the OVA+RSV group， modified Wuhutang down-regulated the protein levels of p-STAT3， p-NF-κB， and NLRP3 （P<0.01）. Compared with the high-dose modified Wuhutang group， the Dxms group showed up-regulated levels of p-STAT3， p-NF-κB proteins （P<0.01）. ConclusionModified Wuhutang can reduce airway inflammation and down-regulate the expression of Muc5AC， p-STAT3， p-NF-κB， and NLRP3 in RSV-infected asthmatic mice， which suggests that Wuhutang reduces airway inflammation in RSV-infected asthma by regulating the STAT3/NF-κB signaling pathway.