Anti-Helicobacter and gastroduodenal cytoprotective actions of the leaf aqueous extract of Ocimum suave (Lamiaceae)

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.