Evaluation of the Gastric Antiulcer Efficacy of Helianthus annuus L, Leaves Extract and Fractions

Peptic ulcer disease is one of the most common gastrointestinal diseases worldwide. Its treatment is becoming increasingly difficult due to the implication of Helicobacter pylori and its increasing resistance to antimicrobial agents leading to a cyclical course of exacerbation and remission. This study evaluated the antiulcer effects of methanol leaf extract and fractions of Helianthus annuus. The crude extract was prepared by cold maceration with methanol. A portion of the extract (300 g) was partitioned with n-hexane, ethyl acetate and methanol to yield n-hexane (HF), ethyl acetate (EF) and methanol (MF) fractions respectively. The extract was subjected to oral acute toxicity (LD50) and phytochemical studies. The antiulcer activity of the extract and fractions was evaluated in rat experimental ulcer models induced with aspirin, ethanol and histamine. Omeprazole and Tween 80 served as the standard drug and negative control respectively. Activities related to antiulcer properties such as effect on gastrointestinal transit and antimicrobial activities were investigated. Outcome measures were ulcer index, percentage ulcer protection, percentage gastrointestinal inhibition and antimicrobial potency. Ulcers induced by the three ulcerogens were significantly (p < 0.05) ameliorated by the extract and the fractions. The extract and fractions significantly (p < 0.05) inhibited gastrointestinal motility in mice. They exhibited potent antibacterial activity but were devoid of anti-fungicidal property. At a dose of 5000 mg/kg (p.o), the extract caused no obvious signs of toxicity or death in mice. Phytochemical analysis revealed the presence of saponins, tannins, flavonoids, steroids, glycosides, terpenoids, as well as reducing sugars. The results show that the leaves of Helianthus annuus possess antiulcer properties with n-hexane fraction offering best ulcer protection. Cytoprotection, antispasmodic, as well as antibacterial actions may account for the mechanisms of the antiulcer effects.