1. Laxative effects and mechanism of action of Brazilian green propolis.
- Author
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Mamoru Kakino, Hiroshi Izuta, Kazuhiro Tsuruma, Yoko Araki, Masamitsu Shimazawa, Kenji Ichihara, and Hideaki Hara
- Subjects
THERAPEUTIC use of plant extracts ,LAXATIVES ,ANALYSIS of variance ,ANIMAL experimentation ,CLONIDINE ,CONSTIPATION ,FECES ,GASTROINTESTINAL motility ,GUINEA pigs ,GUMS & resins ,ILEUM ,MICE ,ORAL drug administration ,T-test (Statistics) ,PLANT extracts ,DATA analysis software ,THERAPEUTICS - Abstract
Background: Brazilian green propolis is reported to have wide range of biological properties including antibacterial, anti-inflammatory, anti-influenza, and antioxidant activities. In the digestive system, a protective effect of propolis on gastric ulcer has been reported, but a laxative effect has not yet been reported. We investigated the effect and the mechanism of action of water and ethanol extracts of Brazilian green propolis. Methods: We examined the laxative effect of propolis on stool frequency by administering orally an ethanol extract of propolis (EEP) or a water extract of propolis (WEP) at 10, 50, 100, or 500 mg/kg to normal mice. We then investigated the effects of propolis using constipation model mice induced by two types of drugs, loperamide (a µ opioid receptor agonist) and clonidine (an α-2 adrenergic receptor agonist). We also investigated the effects of WEP on gastrointestinal transit and contractional tension of the ileum to uncover the mechanism of action of WEP. Results: Treatment with WEP, but not with EEP, significantly increased the weight of stools (p<0.01 at 500 mg/kg). WEP treatment significantly restored stool frequency and stool weight in clonidine-induced constipation model mice, but not in loperamide-induced constipation model mice. WEP treatment did not affect gastro-intestinal transit, but significantly increased the contractional tension of the isolated ileum of guinea pigs. This increase was inhibited by an acetylcholine receptor antagonist (atropine), but not by a 5-HT receptor antagonist (GR113808). Conclusion: These findings indicate that WEP has laxative effects both in normal mice and in clonidine-induced constipation model mice. The laxative effects of WEP might be mediated by increased contractional tension of the ileum exerted at least in part via activation of an acetylcholine receptor. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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