Gastroprotective effects of both aqueous and ethanolic extracts of lemon verbena leaves against indomethacin-induced gastric ulcers in rats

Objective: Lemon verbena (Lippia citriodora) has protective effect agonist gastrointestinal complications. Therefore, we aimed to investigate the protective effects of aqueous and ethanolic extracts of Lippia citriodora leaves on reducing the gastric ulcer induced by indomethacin. Methods & Materials: The rats were divided into groups receiving aqueous and ethanolic extracts of Lemon verbena (50, 100 and 200 mg/kg), zileuton (100 mg/kg), montelukast (10 mg/kg) or 1% tween 80 in the presence or absence of indomethacin (100 mg/kg). The protective materials were administered half an hour before administration of indomethacin. Sixty minutes after administration of indomethacin, the neutrophil percentage was determined, and four hours later, the histopathologic evaluation and malondialdehyde (MDA) measurement in gastric tissue were conducted. Results: Indomethacin produced macroscopic stomach ulcers and increased the neutrophils percentage and MDA level compared to the control group (P<0.001). Co-administration of indomethacin and zileuton, montelukast and ethanolic extract (200 mg/kg) (P<0.001), 200 mg/kg of aqueous extract (P<0.05) reduced ulcer compared to indomethacin group (P<0.001). The ethanolic extracts (100 and 200 mg/kg) and aqueous extract (200 mg/kg) reduced the MDA level (P<0.001). The ethanolic extract (50, 100 and 200 mg/kg), and aqueous extract (200 mg/kg) significantly decreased the neutrophils percentage compared to indomethacin group (P<0.001). Conclusion: Aqueous and ethanolic extracts of Lemon verbena (200 mg/kg) have protective effect on indomethacin-induced gastric ulcers similar to zileuton and montelukast. Ethanolic extract of lemon verbena exhibits higher gastroprotective effect than aqueous extract. The proposed mechanism may be by inhibiting the lipoxygenase enzyme, and inhibition of lipid peroxidation.

Keywords:

NSAIDs , Indomethacin , gastric ulcer , Lemon verbena , Lippia citriodora