The exact pathogenesis of ulcer continues to elude scientists and medical researchers, but a common ground has been proposed. Ulcers are produced when any factor causes an imbalance between the protective factors (mucus and bicarbonate) and aggressive factors (acid and pepsin) in the stomach. The disease has been reported to have high recurrence and mortality rates especially in complicated cases (1, 2). Such factors could range from natural causes (gastric cancer), infections (Helicobacter pylori-H.pylori) and lifestyle (drugs, non steroidal anti-inflammatory agents, alcohol, stress and cigarette smoking) (3, 4).

Current treatment of ulcers in developing countries has been largely suppression of pain, with little or no strategy aimed at a cure. Herbal medicine is fast emerging as an alternative treatment to available synthetic drugs for treatment of ulcer possibly due to lower costs, availability, fewer adverse effects and perceived effectiveness.

Gastric ulcer, one of the most widespread, is believed to be due to an imbalance between aggressive and protective factors (5). The gastric mucosa is continuously exposed to potentially injurious agents such as acid, pepsin, bile acids, food ingredients, bacterial products (H. pylori) and drugs (6). These agents have been implicated in the pathogenesis of gastric ulcer including enhanced gastric acid and pepsin secretion, inhibition of prostaglandin synthesis and cell proliferation growth, diminished gastric blood flow and gastric motility (7).

The goals of treating peptic ulcer disease are to relieve pain, heal the ulcer and prevent ulcer recurrence. Currently there is no cost-effective treatment that meets all these goals. Hence, efforts are on to find a suitable treatment from natural product sources.

Many tropical herbs have been scientifically reported to possess potent anti-ulcer activity (8–10). Capparis zeylanica Linn. (C.zeylanica) commonly known as ‘Asadhua’ in Oriya and ‘Ardanda’ in Hindi is a branched thorny, sub-scandent climbing shrub found throughout India (11). It has been used as a ‘Rasayana’ drug in the traditional Ayurvedic system of medicine. In Northern India, the leaves are widely used as counter-irritant, febrifuge and as a cataplasm in swellings (12), boils and piles (13). Traditionally it is also used as antidote to snake bite, to cure swelling of testicle, small pox, boils, cholera, colic, hemiplegia, neuralgia, sores, pneumonic and pleurisy (14).

Whole plant showed the presence of saponin, p-hydroxybenzoic, syringic, vanillic, ferrulic and p-coumanic acid. Leaves and seeds showed presence of β-carotene, thioglycoside, glycocapparin, n-tricortane, α-amyrin and fixed oil where as root bark showed presence of an alkaloid, a phytosterol, a water soluble acid and a mucilaginous substance (15, 16) . Capparis species has been reported to have antihelmintic, anti microbial and anti inflammatory activities (17, 18). The dried leaves of few species from the genus Capparis, steeped in vinegar were reported to be used for treatment of ulcers (19).

Preliminary phytochemical screening of the Methanolic Extract of C.zeylanica (MECZ) revealed that presence of alkaloids, flavonoids, carbohydrates, glycosides, tannins, terpenoids, phenols and absence of fixed oils and steroids. No visible change was observed in any animal and all survived till 24 hr; thus based on preliminary study, different extracts of C.zeylanica were found to be safe for further biological studies, as no lethality was observed at 1000 mg/kg (p.o) in mice. Acute toxicity results showed that the LD50 was greater than 5000 mg/kg.

In aspirin plus pylorus ligation induced gastric ulcer, the methanol extract of C.zeylanica showed significant reduction in gastric volume, free acidity and ulcer score (% ulcer inhibition 57.83% as compared to control (Table 1). From Table 2 it can be observed that the number of lesions in HCl-ethanol induced peptic ulcer group was significantly high and the methanol extract of C.zeylanica pre-treated group depicted marked reduction (p<0.01) in gastric lesion (% ulcer inhibition 88.5%) as compared to control (Table 2).

Results for indomethacin model can be viewed in Table 3. There was an absolute production of severe ulcers in all the rats using this model and ulcer inhibition was seen in all the treatment groups. Ulcer inhibition was highest with 200 mg/kg MECZ (83.78%, p>0.01) and lowest with Sucralfate (48.74%).

The anti-ulcer activity of the methanol extract of C.zeylanica against ethanol, aspirin and indomethacin-induced ulcers was established in this study. Results of acute toxicity showed that the plant is safe as exemplified by its use as food in domestic and wild animals. The extract protected the stomach against ethanol's necrotic damage and its effect was more pronounced than sucralfate, a cytoprotective agent.

Ethanol has been shown to increase the risk of ulcer in humans (2), but produces potent ulceration in rats (26). Ethanol challenge induces gastric injury due to production of oxygen free radicals leading to increased lipid peroxidation, which causes damage to cell and cell membrane presenting as red streaks of sores (27). The protection by the extract of this type may suggest a possible cytoprotective mechanism of action.

Indomethacin model produces its ulceration by mechanism well understood. It causes an inhibition of the production of endogenous cytoprotective prostaglandins (28). However, with the inhibition of ulcer in this model by the extract, it is possible that the plant produces a cytoprotection similar to those of Omeprazole in the indomethacin model. The secondary metabolites identified may also have been responsible for the anti-ulcer activity of this plant as flavonoids have been reported to possess anti-ulcer activity in various experimental models of ulcers (29).

In aspirin plus pylorus ligation induced gastric ulcer model, the methanol extract of C. zeylanica reduced the gastric volume, free acidity and ulcer index thus showing the anti-secretory mechanism involved in the extracts for their anti-ulcerogenic activity. Ulcer index parameter was used for the evaluation of anti-ulcer activity since ulcer formation is directly related to factors such as gastric volume, free and total acidity. In case of vehicle control, aspirin plus pylorus ligation increased the acid secretion, which in turn caused increase in gastric volume, low pH, increased free and total acidity resulting into increase in ulcer index (30).

Ulcer protection may be attributed to any of these phytochemical constituents as flavonoids, tannins and saponins which have been shown to produce anti-ulcerogenic and anti-gastric activity (31). However, until specific constituents are isolated and characterized, exact mechanism of action cannot be ascertained. Studies on the sub acute and chronic toxicity of the extract are however in progress.