doi: 10.1111/j.1472-8206.2009.00726.x ORIGINAL ARTICLE Gastroprotection of (-)-a-bisabolol on acute gastric mucosal lesions in mice: the possible involved pharmacological mechanisms Nayrton Fla ´vio Moura Rocha a , Edith Teles Vena ˆncio a , Brinell Arcanjo Moura a , Maria Izabel Gomes Silva a , Manoel Rufino Aquino Neto a , Emiliano Ricardo Vasconcelos Rios a , Damia ˜o Pergentino de Sousa b , Silva ˆnia Maria Mendes Vasconcelos a , Marta Maria de Franc ¸a Fonteles a , Francisca Cle ´a Florenc ¸o de Sousa a * a Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceara ´, Rua Cel. Nunes de Melo 1127, CEP 60430-270 Fortaleza, Brazil b Department of Physiology, Federal University of Sergipe, CEP 49100-000 Sa ˜o Cristo ´va ˜o Sergipe, Brazil INTRODUCTION Peptic ulcer is an injury of the gastric and duodenal mucosa which occurs where the epithelium is exposed to acid or pepsin [1]. Smoke, stress, alimentary deficiency and use of non-steroidal anti-inflammatory drugs (NSAID), may increase the incidence of gastric ulcer [2]. Intragastric administration of ethanol to mice rapidly induces gastric mucosal lesions, which are commonly used to study both the pathogenesis and therapy of human ulcerative disease. Ethanol rapidly penetrates the gastroduodenal mucosa causing membrane damage, exfoliation of cells and erosion. The subsequent increase in mucosal permeability, together with the release of vasoactive products from mast cells, macrophages, and other blood cells may lead to vascular injury, necrosis, and ulcer formation [3]. Indomethacin, a prostaglandin synthesis inhibitor, is a classic representative of NSAIDs. These drugs are com- monly used to treat inflammatory states and reduce the Keywords a-bisabolol, essential oil, gastric ulcer, GSH Received 10 October 2008; revised 13 March 2009 accepted 23 March 2009 *Correspondence and reprints: clea@ufc.br, cleaflorenco@ yahoo.com.br ABSTRACT (-)-a-Bisabolol is an unsaturated, optically active sesquiterpene alcohol obtained by the direct distillation essential oil from plants such as Vanillosmopsis erythropappa and Matricaria chamomilla. (-)-a-Bisabolol has generated considerable economic interest, since it possesses a delicate floral odor and has been shown to have anti-septic and anti-inflammatory activity. The aim of this work was to evaluate the gastroprotective action of (-)-a-bisabolol on ethanol and indomethacin-induced ulcer models in mice, and further investigate the pharmacological mechanisms involved in this action. The oral administration of (-)-a-bisabolol 100 and 200 mg/kg was able to protect the gastric mucosa from ethanol (0.2 mL/animal p.o.) and indomethacin-induced ulcer (20 mg/kg p.o.). Administration of L-NAME (10 mg/kg i.p.), glibenclamide (10 mg/ kg i.p.) or indomethacin (10 mg/kg p.o.) was not able to revert the gastroprotection promoted by (-)-a-bisabolol 200 mg/kg on the ethanol-induced ulcer. Dosage of gastric reduced glutathione (GSH) levels showed that ethanol and indomethacin reduced the content of non-protein sulfhydryl (NP-SH) groups, while (-)-a-bisabolol significantly decreased the reduction of these levels on ulcer-induced mice, but not in mice without ulcer. In conclusion, gastroprotective effect on ethanol and indometh- acin-induced ulcer promoted by (-)-a-bisabolol may be associated with an increase of gastric sulfydryl groups bioavailability leading to a reduction of gastric oxidative injury induced by ethanol and indomethacin. ª 2009 The Authors Journal compilation ª 2009 Socie ´ te ´ Franc ¸aise de Pharmacologie et de The ´ rapeutique Fundamental & Clinical Pharmacology 24 (2010) 63–71 63