Background: Evidences show that Aloe vera (A. vera), Camellia sinensis, Hibiscus sabdariffa and Sophora alopecuroides may prevent gastric ulcer induced by non-steroidal anti-inflammatory drugs (NSAIDs).

Objective: To examine the protective potential of these plants against indomethacin-induced gastric ulcer in the rat.

Methods: Saline, A. vera leaf gel powder and 70% alcoholic extracts of the other 3 plants (100, 400, 800 mg/kg) and omeprazole (30 mg/kg) were gavaged to the groups of 10 animals for 4 consecutive days. Gastric ulcers were induced by the onetime gavage of indomethacin (30 mg/kg). On the fifth day, each group was pretreated with physiological saline as control, extract (100, 400 or 800 mg/kg) or omeprazole (30 mg/kg) 30 min before the indomethacin administration. The animals were killed 6 h after the indomethacin administration. The stomachs were removed, opened along the greater curvature and washed in physiological saline. A person unaware of the type of treatment received by the animals examined the stomachs under a 3-fold magnifier. The areas and lengths of hemorrhagic lesions induced by indomethacin were measured using a dial caliper and the sum of measurements for each animal was referred to as the ulcer index.

Results: All doses of the A. vera leaf gel powder and extracts reduced the ulcer index significantly compared to the control group (p < 0.05).

Conclusion: These plants have protective effect against NSAID-induced gastric ulcer in the rat. The A. vera leaf gel seems noticeably more effective than the other 3 plants in this respect.