Journal of Medicinal Plants Research Vol. 6(12), pp. 2266-2275, 30 March, 2012 Available online at http://www.academicjournals.org/JMPR DOI: 10.5897/JMPR10.409 ISSN 1996-0875 ©2012 Academic Journals Full Length Research Paper Anti-ulcer activity of Swietenia mahagoni leaf extract in ethanol-induced gastric mucosal damage in rats Salmah Al-Radahe 1 , Khaled Abdul-Aziz Ahmed 2,3 *, Suzy Salama 2 , Mahmood Ameen Abdulla 2 , Zahra A. Amin 2 , Saad Al-Jassabi 1 and Harita Hashim 4 1 Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia. 2 Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. 3 Department of Medical Sciences, Faculty of Dentistry, Ibb University, P. O. Box 70627, Ibb, Yemen. 4 Department of Biology, Faculty of Applied Science, University Teknologi MARA 40450 Shah Alam, Malaysia. Accepted 13 April, 2011 Swietenia mahagoni (West Indian mahogany) has been reported to have medicinal uses, such as treatment for hypertension, cancer, amoebiasis, chest pains and intestinal parasitism. The present study was performed to evaluate the acute toxicity and anti-ulcer activity of S. mahagoni ethanol leaf extract against ethanol-induced gastric ulcer. 24 rats included in this study were divided into 4 groups with 6 rats each group. Group 1 rats (ulcer control group) were pre-treated with vehicle (Carboxyl methyl cellulose). Group 2 (reference group) was orally pretreated with 20 mg/kg omeprazole. Group 3 and 4 (experimental groups) were orally pre-treated with S. mahagoni ethanol leaf extract at 250 and 500 mg/kg doses, respectively. After one hour later, all groups received absolute ethanol to generate gastric mucosal injury. After an additional hour, all the rats were sacrificed and the ulcer areas of the gastric walls were determined. Grossly, the ulcer control group exhibited severe mucosal injury, whereas pre- treatment with either omeprazole or plant extract resulted in significantly protection of gastric mucosal injury and increase in mucus production. Flattening of gastric mucosal folds was also observed in rats pretreated with S. mahagoni leaf extract. Histological studies of the gastric wall of ulcer control group revealed severe damage of gastric mucosa, along with edema and leucocytes infiltration of the submucosal layer compared to rats received either omeprazole or S. mahagoni leaf extract where there was marked gastric protection along with reduction or absence of edema and leucocytes infiltration of the submucosal layer. Acute toxicity study with a higher dose of plant extract at 5 g/kg did not reveal any toxicological signs in rats. In conclusions, the present findings suggest that S. mahagoni ethanol leaf extract exhibit an anti-ulcer activity against ethanol-induced gastric ulcer in experimental animals. Key words: Swietenia mahagoni leaf extract, gastric ulcer, histology. INTRODUCTION Various parts of Swietenia mahagoni have been used as folk medicine for the treatment of hypertension, malaria, cancer, amoebiasis, chest pains, fever, anemia diarrhea, dysentery, depurative and intestinal parasitism (Nagalakshmi et al., 2001; Maiti et al., 2007). Other studies have showed other medicinal values of S. mahagoni plant like antibacterial (Majid et al., 2004) and *Corresponding author. E-mail: khaaah@gmail.com. antioxidant activities (Sahgal et al., 2009a) as well as diabetes therapy (Li et al., 2005). The biologically active ingredients, tetranortriterpenoids and fatty acids, are considered to be responsible for these therapeutic effects (Bacsal et al., 1997). Previous phytochmical investigations on S. mahogani have led to the isolation of more than 45 limonoids belonging to the structural types of andirobin, gendunin, mexicanolide, phragmalin, triterpens, tetranortriterpenes, and chlorgenic acid (Abdelgaleil et al., 2006; Chen et al., 2007). From S. Mahagoni, eighteen tetranotriterpenoids Wer isolated (Kadota et al., 1990) and the presence of