Abstract: Objective: To study the effect of Semen Plantaginis polysaccharidesm on defecating function in constipated mice. Methods: Male Kunming mice were randomly divided into control group, model control group, positive control group and 3 dosages groups. Mice of 3 dosages groups were administered with different concentrations of polysaccharides from Semen Plantaginis (0.1, 0.2, 0.4g/kg bw) by mouth for 8 days; mice of control group and model control group were administered with distilled water of 20 ml/kg bw for 8 days; the mice of positive control group were administered with Maren Wan of 1.0 g/kg bw for 8 days. Then the time for the first black feces to be excreted and the number mice feces within 5 hours was observed, water percent of mice feces and ink propelling rates was mensurated. Results: Semen Plantaginis Polysaccharides could markedly shorten the time for the first black feces to be excreted, Increased the number of mice feces within 5 hours. Water percent of mice feces and ink propelling rates were markedly increased too. Conclusion: Semen Plantaginis polysaccharides has the effect ofd efaecation.

Key words: Semen Plantaginis polysaccharides, defecation, mice, constipation