Phytochemical Screening, Evaluation of Anti-Peptic Ulcer Activities of Aqueous Leaf Extract of Neem Azadirachta indica A. Juss (Meliaceae) in Wistar Rats

Abstract

Introduction: Peptic ulcer disease (PUD) is a major public health concern, affecting up to 10% of the world’s population. This disease results from an imbalance between the gastro protective and aggressive factors of the gastric mucosa. Prevalence of PUD is about 10% in Cameroon and conventional medications used to treat ulcers are not easily accessible to the population in the rural areas. The drugs are expensive to the poor population and comes with numerousside effects, thus causing many patients residing in rural areas to rely on herbal medicines. The herbal medicines include herbs, herbal materials, herbal preparations and finished herbal products, that contain as active ingredients parts of plants, or other plant materials, or combinations). World Health Organization (WHO), records that at least 80% of the world’s population depends on herbal medicine products. Herbal therapy is believed toto promote healthier living. Azadirachta indica is a treethat is common in the Northern parts and sparsely distributed in the Northwest Region of Cameroon. It is used as a remedy for several pathologies, amongst which we have gastric ulcers which is our area of interest. Objectives: To qualitatively identify the secondary metabolites present in the aqueous leaf extract of A. indica and investigate its preventive and curative activity on gastric ulcers Methods: The aqueous leaf extract was phytochemically screened following the method used by Prashanth and Krishnaiah. The extract was screened for the presence of sulphite ions which could be useful in ulcer prevention/healing. For in vitro investigations, the antacid properties (using the Food and Drug Administration (FDA) test) was tested, the acid neutralization capacity, acid neutralization speed (Rossett-Rice method) and buffering capacity (Holber’s method). Ulcers were induced using the absolute ethanol and hydrochloric acid experimental model. Various biochemical parameters such as the: MDA, Catalase, Glutathione, Pepsin, SOD, ASAT, ALAT, Creatinine, XO, and total proteins, were quantified. Ulcer preventive and curative properties of three doses (12.5, 25 & 50 mg/Kg) of the extract were compared with a positive control (Sucralfate 25 mg/Kg) and a negative control Histological studies of the stomach were conducted, after samples were exposed to herbal products. Results: Phytochemical screening of the A. indica aqueous leaf extract showed the presence of mucilage, tannins specifically catechin, flavonoids, total polyphenols, coumarins and phlobotannins. The leaf extract tested positive for ferric, iodide, carbonate, sulphite ions, as well as proteins. These bioactive molecules showed promising antiulcer and antioxidant properties. The neem leaf extract (NLE) fulfilled the FDA conditions for an antacid, had a capacity to buffer an acid milieu for about 40 minutes and had a neutralization capacity well within the designed pH range of 3.5 – 5. The preventive and curative studies showed significant reduction in the gastric juice and ulcer surface. A percentage inhibition of 71.27 in the preventive studies and percentage regeneration of 99.33 for curative studies was obtained from rats dosed at50 mg/Kg body weight. Conclusion: This study showed that the aqueous extract of Azadirachta indica leaves had a promising gastro-protective and gastric healing activities in rats at 50 mg/Kg.