Banxia Xiexin decoction promotes gastric lymphatic pumping by regulating lymphatic smooth muscle cell contraction and energy metabolism in a stress-induced gastric ulceration rat model

The roles of lymphatic pumping disorder in gastrointestinal diseases have drawn increasing research attentions. A Traditional Chinese medicine (TCM) formula Banxia Xiexin decoction (BXD) has definite therapeutic effect in treating stress-induced gastric ulceration (SIGU) and many other gastrointestinal diseases, but its effect on gastric lymphatic pumping (GLP) remains unclear. This study used tracer-aided in vivo imaging to illustrate BXD’s GLP recovery effect in a SIGU rat model, and explored the underlying mechanisms via RNA sequencing (RNA-Seq) and transcriptomic analysis of gastric lymphatic vessel (GLV). The result indicated the possible mechanisms included smooth muscle contraction signaling pathway activation, energy supply restoration, energy metabolic program modulation and fatty acid degradation reduction. The most probable target of these mechanisms was the lymphatic smooth muscle cells (LSMCs) which drove the GLP. The transcriptomic results were further validated by the assessments for expression level of key genes and proteins. By GLP recovery and lymphostasis clearance, BXD effectively ameliorates the accumulation of inflammatory cytokines and metabolic wastes in the stomach, which contributes a lot to its efficacy in treating SIGU and other gastrointestinal diseases. In vivo GLP imaging were performed on SIGU rat model, and the lymphatic dynamic parameters were evaluated. Gastric antrum tissues and serum were collected for macroscopic, histopathological and ulcerative parameters analysis. Gastric lymphatic vessel (GLV) tissues were collected for RNA-Seq assays. Differentially expressed genes (DEGs) were screened from RNA-Seq result and submitted for transcriptomic analysis. Key DEGs and their derivative proteins were measured by qRT-PCR and WB.