%0 Journal Article
%T Antioxidant Capacity, Cytoprotection, and Healing Actions of the Leaf Aqueous Extract of Ocimum suave in Rats Subjected to Chronic and Cold-Restraint Stress Ulcers
%A Paul V. Tan
%A C. Mezui
%A G. E. Enow-Orock
%A G. Agbor
%J Ulcers
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/150780
%X We evaluated the qualitative chemical composition and tested the antiulcer actions on cold/restraint stress ulcers, the healing effect on chronic acetic acid-induced gastric ulcers, and the in vivo and in vitro antioxidant capacity of Ocimum suave extract. Triterpenes, flavonoids, sugars, phenols, sterols, and multiple bonds were among the phytochemicals detected. The extract (250¨C500£¿mg/kg) dose-dependently inhibited the formation of gastric ulcers induced by cold/restraint stress (52.30%¨C83.10%). The prophylactic actions were associated with significant increases in gastric mucus production. There was significant histological healing of chronic ulcers following 14-day treatment with O. suave extract (250¨C500£¿mg/kg). We also evaluated the efficacy of O. suave extract in cold/restraint-induced oxidative stress in rat stomach tissue. O. suave (500£¿mg/kg) ameliorated the decreased levels of reduced glutathione from 0.85 (control group) to 2.08£¿nmol/g tissue. The levels of SOD and catalase were also improved in rats treated with O. suave extract. The extract had a high phenol content (899.87£¿mg phenol/g catechin equivalent), in vitro DPPH radical scavenging activity (89.29%), and FRAP (antioxidant capacity) (212.64£¿mg/g catechin equivalent). The cytoprotective and ulcer healing effects of the extract are attributed to enhanced mucus production and the antioxidant properties which may likely be associated with the high presence of flavonoids and polyphenols. 1. Introduction The stressful nature of modern life makes the gastroduodenal viscus susceptible to physical and nervous stress. In the latter situation, vagal stimulation can cause hypersecretion of acid and pepsin resulting in gastroduodenal ulceration enhanced by the release of stress hormones of the steroid type [1]. Experimentally-induced ulcers of the cold/restraint type in laboratory animals are regularly used to mimic the real life stress situation in humans and permit the evaluation of the stress ulcer inhibiting effects of drugs and plant-derived antiulcer preparations. Lipid peroxidation has been linked to the mechanism of cold stress ulcer induction. In rats, water immersion/restraint stress stimulates lipid peroxidation and sulphydryl oxidation via oxygen free radicals generated by the xanthine-xanthine oxidase system, and infiltrated neutrophils in gastric mucosal tissue are involved in the progression of acute gastric mucosal lesions [2]. Oxygen-derived free radicals are cytotoxic and promote tissue injury, while radical scavengers stimulate the healing of refractory peptic ulcers [3].
%U http://www.hindawi.com/journals/ulcers/2013/150780/