Open Access Research article

Laxative effects of agarwood on low-fiber diet-induced constipation in rats

Mamoru Kakino1, Shigemi Tazawa2, Hiroe Maruyama2, Kazuhiro Tsuruma1, Yoko Araki2, Masamitsu Shimazawa1 and Hideaki Hara1*

Author Affiliations

1 Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu 501-1196, Japan

2 Nagara Research Center, API Co., Ltd., 692-3 Nagarayamasaki, Gifu 502-0071, Japan

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BMC Complementary and Alternative Medicine 2010, 10:68  doi:10.1186/1472-6882-10-68

Published: 15 November 2010

Abstract

Background

Agarwood (Aquilaria sinensis), well known as incense in Southeast Asia, has been used as a digestive in traditional medicine. We investigated the laxative effects of an ethanol extract of agarwood leaves (EEA) in a rat model of low-fiber diet-induced constipation.

Methods

A set of rats was bred on a normal diet while another set was placed on a low-fiber diet to induce constipation. The laxative effect of agarwood was then investigated on both sets of rats.

Results

Pretreatment of normal rats with single dose of EEA (600 mg/kg, p.o.) significantly increased frequency and weight of stools. Also, treatments with EEA (300 and 600 mg/kg, p.o.) for 14 days caused a significant increase in stool frequency and weight. Feeding of the animals with a low-fiber diet resulted in a decrease in stool weight, frequency, and water content and also delayed carmine egestion. A single treatment with EEA (600 mg/kg) or senna (150 and 300 mg/kg) significantly increased stool frequency, weight, and water content and also accelerated carmine egestion in the model rats. Once daily administrations of EEA (150 mg/kg), for 14 days, caused a significant increase in water content of stools. The higher doses of EEA (300 and 600 mg/kg) significantly increased frequency, weight, and water content of the stools while accelerating carmine egestion in the constipated rats. Senna (150 and 300 mg/kg) produced similar effect as the higher doses of EEA but, in addition, induced severe diarrhea.

Conclusion

These findings indicate that EEA has a laxative effect, without causing diarrhea, in a rat model of low-fiber diet-induced constipation. These findings suggest that EEA may be highly effective on constipation as a complementary medicine in humans suffering from life style-induced constipation.