Antiulceer activity, Phytochemical screening acute toxicity and bioavailability of Azadirachta indica (Meliaceae) aqueous Leaf extract in wistar rats

Pharmacotoxicology and pharmacokinetics, Université of Yaoundé I
June, 2018


Introduction: This alternative form of medicine, in the recent years has gained its place and most often involves the use of one or more plant or parts of plants. The Neem Tree has been tested and proven for several pathologies. This study investigates its effect on the prevention and treatment of ulcers
Objectives: To qualitatively identify the secondary metabolites present in the aqueous leaf extract of A. indica, screen the serum of rats dosed with the extract for the presence of these secondary metabolites, investigate its antiulcer activity and evaluate the acute oral toxicity.
Method: The extract was screened according to the Odebiyi-Sofowora method, for the presence of secondary metabolites and ions. Antacid properties of the NLEa were investigated through the FDA test for antacids, the acid neutralization capacity and buffering capacity. Ulcers were induced using the HCL/ethanol (150 mM/60%) model. Three doses (12.5, 25 and 50 mg/Kg) of the extract were compared with a positive and negative control, for antiulcer activity. Acute toxicity was at a single dose, 2000 mg/Kg of NLEa. The rat serum was screened to evaluate possible bioavailability.
Results: The phytochemical screening of the aqueous leaf extract showed the presence of mucilage, tannins specifically catechin, flavonoids, total polyphenols, coumarins and phlobotannins, as well as ferric, iodide, carbonate, sulphite ions, as well as proteins. Six out of seven of the phytochemicals found in the plant were bioavailable. The NLEa fulfilled the conditions for an antacid. The preventive and curative studies showed significant reduction in the ulcer surface at 50 mg/Kg. The administration of 2000 mg/Kg was well tolerated with no lethality during the study.
Conclusion: This study proves that the aqueous extract of Azadirachta indica leaves has gastro-protective and gastric healing activities in rats at 50 mg/Kg. It is bioavailable, and at the dose of 2000 mg/Kg, it is safe.