Abstract: Objective: To investigate the ameliorative effect of Mirabilis jalapa root extract on loperamide-induced constipation in
mice, providing experimental evidence for its development and application in constipation treatment. Methods: A constipation model
was established in mice by intragastric administration of loperamide. The animals were randomly divided into a normal control group, a
model group, a positive control group, and low-, medium-, and high-dose M. jalapa extract groups, with continuous administration for
7 days. Defecation function was assessed by general condition, first black stool excretion time, the number of fecal pellets within 6
hours, and fecal water content. Gastric phenol red retention and small intestinal transit rate were measured using the phenol red
method. Colonic water content was determined to evaluate colonic hydration. Results: Compared with the normal group, the model mice
exhibited a significantly prolonged time to first black stool, reduced fecal pellet number, decreased fecal and colonic water content,
along with increased gastric phenol red retention and decreased intestinal transit rate (P<0.05), confirming successful model establishment.
Compared with the model group, medium- and high-dose M. jalapa extract significantly shortened the time to first black stool,
increased fecal pellet number within 6 hours, and improved fecal and colonic water content as well as small intestinal transit rate (P<
0.05). The high-dose extract also markedly reduced gastric phenol red retention (P<0.05), indicating enhanced gastric emptying and
intestinal motility. Conclusion: M. jalapa root extract effectively relieves constipation in mice, improves gastric emptying and small
intestinal transit function, increases fecal and colonic water content, and exerts a clear laxative effect with gastrointestinal motilitypromoting
potential.

Key words: Mirabilis jalapa, constipated mice, gastrointestinal motility, loperamide