ANTI-ULCERS PROPERTIES AND SAFETY PROFILE ASSESSMENT OF AQUEOUS STEM BARK EXTRACT OF Alstonia boonei De Wild (APOCYNACEAE) IN RODENTS
MEZUI CHRISTOPHE *
Department of Animal Biology, Higher Teachers’ Training College, ENS, University of Yaoundé I, P.O.Box 047, Yaoundé, Cameroon
SIWE TCHOKOMENI GAËL
Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, P.O.Box 812, Yaoundé, Cameroon
AMANG ANDRE PERFUSION
Department of Biological Sciences, Faculty of Science, University of Maroua, P.O. Box 814, Maroua, Cameroon
ESSONG OLIVIER
Department of Animal Biology, Higher Teachers’ Training College, ENS, University of Yaoundé I, P.O.Box 047, Yaoundé, Cameroon
BOUMZINA LEFILS
Department of Animal Biology, Higher Teachers’ Training College, ENS, University of Yaoundé I, P.O.Box 047, Yaoundé, Cameroon
EFFOUBA NICAISE
Department of Biology, Higher Teachers’ Training College, ENS, University of Bamenda, Cameroon
ETENDE ATSAMA FRANÇOIS
Department of Animal Biology, Higher Teachers’ Training College, ENS, University of Yaoundé I, P.O.Box 047, Yaoundé, Cameroon
TAN PAUL VERNYUY
Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, P.O.Box 812, Yaoundé, Cameroon
*Author to whom correspondence should be addressed.
Abstract
Purpose: The present work was carried out to evaluate the anti-ulcer activities and the safety level of the aqueous stem bark extract of Alstonia boonei.
Methods: Gastric ulcers were induced respectively by oral administration of indomethacin (50 mg/kg) (acute ulcers) and by an injection of 30% glacial acetic acid in the stomach wall (chronic ulcers). At the end of the assay, mucus secretion, ulcers measurements and stomach histology were realized. Acute toxicity using a single dose of 2000 mg/kg was administered to mice and effects were observed for 14 days. The sub-acute toxicity of the aqueous extract at doses 200 mg/kg, 400 mg/kg and 800 mg/kg, was also studied on rats for 28 days. The control group received distilled water and satellite test groups received the extract (800 mg/kg). Anthropometric, haematological and biochemical parameters were measured and histological sections of liver, kidneys, lungs were realized.
Results: The extract showed ulcers inhibition rates of 27.69%, 37.55% and 57.75% as well as healing rates of 60.69%, 75.06% and 99.37% for the doses of 100, 200 and 400 mg/kg, respectively. At the same time, mucus secretion showed a significant increase (p<0.001) at all the doses. Acute toxicity test showed no signs of toxicity such as general behaviour change, mortality or change in gross appearance of internal organs. Subacute assay revealed few modifications in biochemical parameters in treated groups compared with controls, as well as slight disturbances of the histological structures of liver and kidneys.
Conclusion: The extract demonstrated optimal cytoprotective and ulcer healing activities (at the recommended safe dose of 200 mg/kg) which involved the stimulation of gastric mucus secretion and gastric mucosal re-epithelialisation.
Keywords: Alstonia boonei, gastric ulcers, acute toxicity, subacute toxicity, apocynaceae