Study on the treatment effect of Bx decoction on rat models of reflux esophagitis

Objective: To explore the mechanism of BAN-XIA-XIE-XIN Decoction (Bx Decoction) treatment in rat models of reflux esophagitis. Methods: Rat models of reflux esophagitis were prepared with the method previously reported from this laboratory. Twenty-five models each were left untreated, treated with cisapride (2.5 mg/kg/d) or treated with BAN-XIA-XIE-XIN Decoction (BX) 5.78m/kg/d) respectively. All the models were sacrificed after 4 weeks, acid contents in gastric juice, cholic acid contents in duodenal juice as well as calcitonin-gene-related peptide (CGRP) (with RIA) contents in lower esophageal tissue and plasma were measured. Histologic examination of lower esophageal tissue for degree of esophagitis was also performed in all the models. Besides, 25 animals underwent sham operation only and served as controls. Results: The positive rates of pathologic changes (mucosal inflammation, squamous cell hyperplasia, lamina propria extension and mucosal erosion) were all significantly higher in the non-treated models than those in the BX treated models (P<0.01). Acid contents in gastric juice were significantly lowered with pH significantly increased in the BX treated group (P<0.01). The CGRP contents in esophageal tissue in the BX treated models, though remains lower than those in the 25 animals with sham operation only, were significantly higher than those in non-treated models (P<0.01). The plasma contents of CGRP in the BX-treated models remained significantly higher than those in sham-operation animals (P<0.01), decrease from the very high levels in untreated model was not large enough to be significant. Conclusion: BX-decoction might exert its protective effect on esophageal mucosa through lowering of gastric acidity with modulation of CGRP synthesis. (authors)