ABSTRACT
<p><b>OBJECTIVE</b>To explore the effect of Changji'an Capsule (CA) on mRNA expressions of neuropeptide Y (NPY) in the hypothalamus and colon and serum levels of adreno-cortico-tropic hormone (ACTH) in rats of diarrhea predominant irritable bowel syndrome (IBS-D) model rats.</p><p><b>METHODS</b>Totally 48 SD rats were randomly divided into six groups, i.e., the normal control group, the model group, the Pinaverium Bromide group (PB, 0.018 g/kg), the high dose CA group (2.812 g/kg), the medium dose CA group (1.406 g/kg), and the low dose CA group (0.703 g/kg), 8 in each group. The IBS-D rat model was established by using separation of breast milk + stimulation of acetic acid + constraint of four limbs. Normal saline was given to rats in the normal control group and the model group. All medication lasted for 14 successive days by gastrogavage. The serum content of ACTH was detected by enzyme linked immunosorbent assay (ELISA). The expressions of NPY mRNA in the colon and the hypothalamus were detected using real-time fluorescence quantitative PCR.</p><p><b>RESULTS</b>Compared with the normal control group, the serum ACTH content significantly increased (P < 0.01), the NPY mRNA expression in the colon and the hypothalamus obviously decreased (P < 0.01) in the model control group. Compared with the model group, the serum ACTH obviously decreased in the high dose CA group, the medium dose CA group, and the PB group (P < 0.01, P < 0.05). The NPY mRNA expression in the colon and the hypothalamus were obviously up-regulated in the high dose CA group, the medium dose CA group, the low dose CA group, and the PB group (P < 0.05).</p><p><b>CONCLUSIONS</b>CA could modulate the abnormity of brain-gut axis of IBS-D rats possibly by up-regulating NPY mRNA expressions in the hypothalamus and the colon and down-regulating the ACTH content in the hypothalamic-pituitary-adrenal axis.</p>