Anthocleista vogelii (Loganiaceae) PLANCH. is used in Cameroonian ethnomedicine for the treatment of stomach ache and for curing fever and is used as purgative. Further investigations have shown that the stem bark of this plant possesses potent antiulcer properties. We have investigated the cytoprotective and antisecretory actions of 1-hydroxy-3,7,8-trimethoxyxanthone (AV), the xanthone obtained from the methanol extract of the stem bark. Oral administration of AV at the doses of 1, 2, and 5？mg/kg prevented in a dose-dependent manner ulcers induced by HCl/ethanol (60.90 to 93.22%), Indometacin (46.86 to 89.68%), and pylorus ligation (0.00 to 70.69%). AV reduced pylorus-ligated gastric acid secretion from 134.17？mEq/l in the controls to 118.55, 121.50, and 96.93？mEq/l, respectively, for the 1, 2, and 5？mg/kg doses and increased mucus secretion significantly in a dose-dependent manner in all experimental models. The cytoprotective and antisecretory properties of AV could thus be due to its ability to strengthen gastric mucosal defences through enhanced gastric mucus production. 1. Introduction In Africa and some parts of Europe, gastric peptic ulcers represent 20% of all peptic ulcers [1]. Ulcer results from the imbalance between damaging factors within the lumen and protective mechanisms within the gastroduodenal mucosa [2]. It has been observed that many patients practice automedication using nonsteroidal anti-inflammatory drugs and other classes of drugs [3] that increase the incidence and the prevalence of this ailment. A good number of drugs are now available for the treatment of peptic ulcer and these drugs are broadly classified into two main groups: those that offer cytoprotection by virtue of their effects on mucosal defensive factors and those that decrease or counter acid-pepsin secretion [4]. Reports on clinical evaluation of these drugs show that there are incidences of relapses and adverse effects and danger of drug interactions during ulcer therapy [4]. Hence, the search for antiulcer drugs continues and has also been extended to herbal drugs in order to find sources for new and cheaper novel molecules, which offer better protection and decrease the incidence of relapse. We have demonstrated in previous works the antiulcer properties of the aqueous and methanol extracts of the stem bark of Anthocleista vogelii in rats [5]. This plant is a small tree, which grows in the tropical rain forest areas of West Africa [6]. In African traditional medicine, the stem bark and leaves are used as an anti-inflammatory and antidiabetic and also in the
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