[Nuclear magnetic resonance-based metabolomics revealed metabolite profiles participate in intervention effect of refined moxibustion in gastric ulcer model rats].

OBJECTIVE: To investigate the effect of refined moxibustion on expression of gastric mucosal epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF), and changes of metabolite profiles in gastric ulcer (GU) rats, so as to analyze its mechanism underlying improvement of GU. METHODS: Male SD rats were randomized into control, model, acupoint moxibustion groups (n=6 per group). The GU model was induced by cold-restraint stress. The ignited refined moxa was applied to bilateral "Liangmen" (ST21) and "Zusanli" (ST36) for 3 cones/acupoint, once daily for 7 days. Then, we employed 1H NMR-based metabolomics approach to analyze the metabolic profiles of serum and stomach tissue samples. The conventional histopathological changes of the gastric mucosa were observed by H.E. stain and the expressions of EGFR and VEGF in the gastric mucosa were detected by immunohistochemistry. RESULTS: Compared to the control group, the expression levels of EGFR and VEGF were significantly increased in the model group (P<0.01, P<0.05), and further notably up-regulated in the acupoint moxibustion group (P<0.001, P<0.01). Results of H.E. staining showed damage of the folds of gastric mucosa, disordered arrangement of the glands, infiltration of inflammatory cells and unclear structure of gastric mucosa in the model group, which was relatively milder in the acupoint moxibustion group. 1H-NMR technical analysis showed that in comparison with the control group, 11 and 11 metabolites in the stomach extract and plasma were increased, 10 in the gastric tissue and 3 in the plasma were decreased in the GU model group; while in comparison with the model group, 17 differently expressed metabolites in the gastric extract and 10 metabolites in the plasma restored to their levels of control group after the acupoint moxibustion intervention. These metabolites participate in 12 metabolic pathways including glycine, serine and threonine metabolism, glutathione metabolism, glycine metabolism, alanine, aspartic acid and glutamic acid metabolism, purine metabolism, glyoxylic acid and digarboxylic acid metabolism, biosynthesis of aminoacyl-tRNA, amino sugar and nucleotide sugar metabolism, cysteine and methionine metabolism, citrate cycle, pyruvate metabolism, and the mutual conversion of pentose and glucuronate，suggesting their involvement in moxibustion-induced improvement of GU. CONCLUSION: Refined moxibustion at ST21 and ST36 can up-regulate the expression of EGFR and VEGF in the gastric mucosa and lessen gastric mucosal injury, which may be related to its effects in reducing GU-induced metabolic disorders, including sugar, purine, amino acid, and phospholipid metabolism and antioxidant defense system.

[Endogenous metabolites involving effects of moxibustion on injured gastric mucosal tissue in rats with stomach heat or cold syndrome based on nuclear magnetic resonance spectroscopy].

OBJECTIVE: To investigate the profile of metabolites of gastric mucosa involving the effectiveness of moxibustion in the treatment of syndromes of stomach heat (SH) and stomach cold (SC) by 1H-nuclear magnetic resonance (1H-NMR) spectroscopy in rats, so as to reveal its mechanisms underlying improvement of gastric disorders. METHODS: Male SD rats were randomly divided into control, SH-model, SC-model, SH-moxibustion and SC-moxibustion groups (n＝6 rats/group). The SH-model and SC-model were established by gavage of pepper liquid plus ethanol, and ice water plus NaOH, respectively. Moxibustion was applied to bilateral "Zusanli" (ST36) and "Liangmen"(ST21) for 20 min, once daily for 7days. Histopathological changes of the gastric tissue were observed by H．E. staining. Differential metabolites in the gastric mucosal tissue were detected and the relevant metabolic pathways analyzed by using 1H-NMR, pattern recognition method，and online MetPA (http: //www.metaboanalyst.ca). RESULTS: Compared with the control group, the body mass was decreased significantly from the 4th to 14th day after modeling (P<0.05，P<0.01). After the treatment, the body mass was obviously increased from the 10th day on in both SH-EA and SC-EA groups relevant to the SH and SC model group, respectively (P<0.05，P<0.01). H．E. staining showed severe damage of the columnar epithelial structure of the gastric mucosa and inflammatory cell infiltration in the SH group, and inflammatory cell infiltration in the SC model group, which were relatively milder in both moxibustion groups. 1H-NMR analysis displayed a total of 16 potential biomarkers in the injured gastric mucosa of SH syndrome and 14 biomarkers for the SC syndrome after mode-ling, and 13 metabolites related to SH moxibustion and 8 metabolites related to SC moxibustion after moxibustion interventions, respectively. After moxibustion, among the 13 differential metabolites of the SH syndrome, the effectively up-regulated candidates were isoleucine, creatinine, choline and lactate (P<0.05), and the down-regulated ones were choline phosphate, glycine, alanine, urine pyrimidine, tyrosine, phenylalanine, hypoxanthine, adenosine and nicotinamide (P<0.05). Among the 8 metabolites related to the SC syndrome, creatinine, ethanolamine, choline, adenosine and nicotinamide were markedly increased (P<0.05), and glycine, creatine phosphate and tyrosine remarkably decreased in their levels after moxibustion (P<0.05). MetPA showed that moxibustion could regulate 10 metabolic pathways for SH syndrome and 7 metabolic pathways for SC syndrome. Metabolites and metabolic pathways are mainly involved in functions of amino acid metabolism, energy metabolism and inflammatory response. CONCLUSION: The idea of "moxibustion could be used for heat syndrome" has metabolic substance basis, and its efficacy in repairing the injured gastric mucosa involves regulation of amino acid metabolism, energy balance and inflammation response, and moxibustion for SH and SC syndromes has both generality and specificity in regulating metabolic activities.