Objective: This study investigated the effects of Terminalia chebula Retz. (TC) and its two processed products Rubia cordifolia L. per Terminalia chebula Retz. (RTC) and Euphorbia fischeriana Steud per Terminalia chebula Retz. (ETC) on the secretory activity of somatostatin cells in the small intestine in mice.
Methods: A total of 168 twenty-day-old SPF Kunming mice were randomly divided into seven groups, i.e., the control (saline, 0.1 g/kg), high TC, RTC, ETC and low TC, RTC, and ETC groups, and administered drugs for 28 days. The cellular localization and expression of SS in the small intestine were assessed by immunohistochemistry after drug delivery for 7, 14, 21 or 28 days.
Results: The somatostatin（SS）protein was widely distributed in the small intestines of mice. Immunoreactivity gradually decreased in the duodenum to the ileum. SS immunoreactivity was significantly lower in the high TC, RTC, ETC and low RTC, and ETC groups compared with the control group after drug delivery for 28 days. The efficacy of RTC was better than that of ETC and obviously better than that of TC. The efficacies of high dosages of TC and its processed products were better than those of low dosages of the drugs. SS cells of various shapes, including cone-, spindle-, and ellipse-shaped SS cells, were observed. A large number of SS cells were found in the intestinal gland epithelium and intestinal lamina propria in the control group, and these cells were widely distributed in epithelial cells in the intestinal mucosa and intestinal gland epithelium in the experimental groups.
Conclusions: This study indicates that TC and its processed products play an important role in inhibiting the secretion of SS to different degrees. The effect of the RTC at a dosage of 4.0 g·kg–1 BW is the best.