Abstract

The gastroduodenal cytoprotective potential of the leaf aqueous extract of Ocimum suave(Lamiaceae) was investigated in rats using several ulcer-inducing methods. The anti-Helicobacter property of the extract was further assessed in vitro against Helicobacter pyloriCCUG-39500. The results obtained indicated that in all cases, orally administered extract (125 to 500 mg/kg) dose-dependently prevented lesion formation, with significant increases in gastric mucus production. The dose-500 mg/kg completely inhibited HCl/ethanol lesions but intraperitoneal indomethacin did not significantly reduce this effect. Honey-250 mg/kg, in combination with the extract-250 mg/kg, offered 50% prevention of ethanol-induced lesions, but O. suave alone (500 mg/kg) was more potent (62% inhibition) compared with honey alone (35% inhibition) at the same dose. In pylorus ligation, gastric acidity (91 mEq/L) was high compared with the controls (68 mEq/L), but 79% lesion inhibition was achieved. Mucus secretion (116 mg at 500 mg/kg) was most significant in highly acidic gastric environments compared with the controls (53 mg). The extract (12 mg) had anti-H. pylori effects (inhibition diameter, 33 mm; minimum inhibitory concentration (MIC), 1.17 mg/ml; minimum bactericidal concentration (MBC), 2.34 mg/mg). The cytoprotective actions of the extract are associated with its gastric mucosal re-enforcing effects. The extract possesses both anti-Helicobacterand gastro-duodenal cytoprotective effects, and may be useful in an antiulcer regimen without antimicrobial, antacids and antisecretory agents.

Key words: Helicobacter pylori, Ocimum suave, cytoprotection, gastroduodenal ulcer.