Planta Med 2011; 77 - PM94
DOI: 10.1055/s-0031-1282852

An approach to studying the mechanism of action of STW 5 in functional dyspepsia using the restraint stress model in rats

MT Khayyal 1, H Abdel Aziz 2, W Wadie 1, HF Zaki 1, O Kelber 3, D Weiser 3
  • 1Department of Pharmacology, Faculty of Pharmacy, Cairo University, Kasr-El-Aini Street, 11562 Cairo, Egypt
  • 2Departments of Pharmacology, Faculty of Pharmacy, Heliopolis University, Egypt and Institute of Pharmaceutical Chemistry, Hittorfstr. 58, 48149Münster, Germany
  • 3Scientific Department, Steigerwald Arzneimittelwerk GmbH, Havelstr.5, 64295 Darmstadt, Germany

While the clinical efficacy of medicinal plants as therapeutic options in treating functional gastrointestinal diseases is widely accepted, the understanding of their mechanisms of action still remains uncertain. Two models for stress-induced functional dyspepsia were performed in order to choose the more adequate one for testing sensitivity changes of the fundus to various mediators. In one model, maternal separation (1) was performed on weanling rats starting from postnatal day 2 for 3h each day for 3 weeks. Rats were then allowed to mature to an adult age. The other model was that of restraint stress (2,3). Adult animals were restrained for 90min/day for 1 week. The animals were eventually sacrificed, the stomach fundus was isolated and its sensitivity in vitro to carbachol, potassium chloride, serotonin and adrenaline was tested. The sensitivity of the fundus strips from restrained rats towards these agents was more depressed than those from maternally separated ones. That model was therefore chosen to test the efficacy of STW 5 in restoring sensitivity to the agents mentioned. A group of animals received STW 5 orally once daily for 2 weeks before subjecting them to restraint stress. Treatment with STW 5 was effective in normalizing the depressed responses exhibited by animals subjected to restraint stress. Samples of blood were taken to assess levels of CRF and ghrelin. The findings throw further light on the mechanisms underlying the therapeutic usefulness of STW 5 in functional dyspepsia, especially when triggered by psychological stress.

Keywords: Functional dyspepsia, STW 5, Stomach fundus, restraint-stress

References: 1. Cheung CK et al. (2010) Gastroenterology138: S-766

2. Zhang H et al. (2008) Phytomedicine 15: 602–611.

3. Zheng J et al. (2009) Am J Physiol Regul Integr Comp Physiol 296: R1358- R1365.