薬理と治療

Abstract

Objectives We have revealed the efficacy and safety of Aquilaria subintegra （agarwood）leave extract on constipation-related symptoms. To evaluate the effect of low dosage of agarwood leaves extract, two clinical trials were performed in this study. Methods Clinical trial-1. We conducted a double-blinded, placebo-controlled, crossover trial in seventeen healthy volunteers-（ages 20 to 65 years old）with mild constipation. For the trial, we prepared a tablet containing a mixed powder of 75 mg agarwood leaves- extract and 75 mg dextrin. The subjects ingested placebo or 150 mg of the agarwood leave extrac（t 2 tablets daily） for 4 weeks. Clinical trial-2. We conducted the trial, which methods were the same as clinical trial-1, with twofold dosage of the agarwood leave extract. Fifteen healthy volunteers with mild constipation were participated in this trial. In each trial, the primary endpoints were changes in self-reported stool smell and the frequency of defecation. Results Clinical trial-1. No significant differences were indicated in any endpoints. And any clinically critical adverse events were not observed in this trial. Clinical trial-2. Significant improvements were indicated in the primary endpoints, the stool volume and the total frequency of defecation. Especially, the stool smell was improved at first week in the intake period of agarwood leaves extract tablets. In addition, any clinically critical adverse events were not observed during the trial. Conclusions Present results suggested that the intake of 300 mg of the agarwood leave extract serves to relieve constipation without adverse effects.