OBJECTIVE

2

To investigate the effects and potential mechanisms of Xiaoqinglong decoction on airway inflammation in asthma with syndrome of cold retention accumulation in lung based on the metastasis-associated lung adenocarcinoma transcript 1 （MALAT1）.

METHODS

2

Forty Wistar rats were randomly divided into blank group， model group， dexamethasone group （positive control， 1 mg/kg）， and Xiaoqinglong decoction group （2.72 g/kg）， with 10 rats in each group. A rat model of asthma with syndrome of cold retention accumulation in lung was established， and the corresponding drugs were administered once daily starting from the second day of modeling for 21 consecutive days. Lung histopathological changes and lung function were evaluated. The levels of superoxide dismutase （SOD）， malondialdehyde （MDA）， interferron-γ （IFN-γ）， tumor necrosis factor α （TNF-α）， and interleukin-13 （IL-13） in serum were measured， and the mRNA expressio

n levels of MALAT1， TNF-α， IL-13， IFN-γ， and transient receptor potential melastatin 2 （TRPM2） in lung tissue were determined. Twenty C57BL/6J wild-type mice and twenty C57BL/6J

MALAT1

（－/－）

mice were randomly divided into wild-type model group， wild-type Xiaoqinglong decoction group，

MALAT1

（－/－）

model group， and

MALAT1

（－/－）

Xiaoqinglong decoction group， with 10 mice in each group. The same asthma model was established， and Xiaoqinglong decoction was administered once daily for 21 days starting from the second day of modeling. The serum levels of SOD， MDA， IFN-γ， TNF-α and IL-13 were measured， along with the mRNA and protein expression levels of TRPM2 in lung tissue.

RESULTS

2

The results of the rat experiment showed that， compared with model group， the airway resistance， functional residual capacity， the serum levels of IL-13， TNF-α and MDA as well as inflammatory infiltration and collagen fiber deposition in lung tissue， and the expressions of IL-13， TNF-α and TRPM2 in lung tissue were all significantly decreased in the treatment group （

P

＜0.05 or

P

＜0.01）. The peak expiratory flow， forced expiratory flow at 50% of forced vital capacity， the serum levels of SOD and IFN-γ， and the expression levels of IFN-γ and MALAT1 in lung tissue were significantly increased （

P

＜0.05 or

P

＜0.01）. The results of the mice experiment demonstrated that， compared with the wild-type model group， serum levels of IL-13， TNF-α and MDA in wild-type xiaoqinglong decoction group were significantly reduced （

P

＜0.05 or

P

＜0.01）， while serum IFN-γ levels and SOD activity were significantly increased （

P

＜0.01）. Compared with the wild-type Xiaoqinglong decoction group， the

MALAT1

（－/－）

Xiaoqinglong decoction

group showed significantly decreased serum IFN-γ levels and S

OD activity （

P

＜0.01）， along with significantly increased levels of IL-13， TNF-α and MDA （

P

＜0.05 or

P

＜0.01）， as well as significantly elevated TRPM2 mRNA and protein expression in lung tissue （

P

＜0.05）.

CONCLUSIONS

2

Xiaoqinglong decoction may alleviate airway inflammation by regulating the expression of MALAT1， modulating oxidative stress， inhibiting TRPM2 activation， and reducing the release of pro-inflammatory cytokines.