Objective:

2

To elucidate the mechanism of Banxia Houpo Decoction (BHD) in treating gastroesophageal reflux disease (GERD) by integrating and utilizing the compound analysis

network pharmacology

and empirical verification.

Methods:

2

Ultra-high performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS) was utilized to identify the primary compounds in BHD. Network pharmacology was employed to retrieve target genes. A GERD rat model was developed and 32 SD rats were randomly divided into model

BHD-L (3 g/kg)

BHD-H (6 g/kg)

and mosapride (0.75 mg/kg) groups using a random number table

8 rats in each group. Eight rats without the construction of a GERD model were selected as the blank group. Esophageal damage was evaluated through visualization and histopathology evaluation. 5-hydroxytryptamine (5-HT) levels in serum and lower esophageal sphincter (LES) were determined by ELISA. LES contractility was measured with a force transducer

and serotonin transporter (SERT) and 5-HT4R expressions in LES were assessed by RT-PCR

Western blot

and immunofluorescence staining

respectively.

Results:

2

UPLC-HRMS analysis identified 37 absorption peaks and 157 compounds in BHD. Functional enrichment identified SERT as a significant target for LES contractility. Histopathological findings indicated less severe esophageal mucosal damage in the BHD-H group compared with the model group. Although serum 5-HT levels showed no significant difference

5-HT concentration in LES tissue was notably higher in the BHD-H group (

P

<

0.05). Within the range from 10

-10

to 10

-7

mmol/L

LES contractility in the BHD-H and mosapride groups was significantly increased (

P

<

0.05). Within the range from 3×10

-7

to 3×10

-6

mmol/L 5-HT

LES contractility in the BHD-H group was increased (

P

<

0.05). No significant difference was detected within the range from 10

-5

to 10

-4

mmol/L 5-HT. Notably

SERT expression in the BHD-H group assessed by RT-PCR

Western blot

and immunofluorescence staining were significantly lower than that in the m

odel group (all

P

<

0.01); while 5-HT4R expression remained unchanged.

Conclusion:

2

BHD may increase LES contractility by inhibiting SERT expression in LES tissue.