Apigenin improves chronic gastric ulcer in rats: The implication of COX-1/2 and 5-LOX signaling pathways.

Peptic ulcer is a prevalent gastrointestinal illness. The aim is to investigate the possible implication of cyclooxygenase (COX)-1/2 and 5-lipoxygenase (5-LOX) signaling pathways in apigenin therapeutic effect on acetic acid-induced chronic gastric ulcer maintained with indomethacin. Rats were divided into 5 groups (n = 10): control, ulcer, omeprazole+ulcer, apigenin+ulcer, and apigenin only groups. Evaluations were for serum oxidative stress markers, gastric acidity, histopathology, immunohistochemistry, and scanning electron microscope (SEM). The ulcer group demonstrated body weight loss, increase in gastric acidity, decline in superoxide dismutase (SOD) and catalase (CAT) antioxidant activity, increase in malondialdehyde (MDA) level, decrease in COX-1 immuno-expression, and increase in COX-2 and 5-LOX immuno-expressions. Furthermore, histopathology revealed mucosal sloughing, and parietal cell degeneration, in addition to completely degenerated mucosa. These parameters were modulated in apigenin-treated group compared to ulcer one, via improved weight gain (37.11 vs. 21.23 g) (omeprazole = 30.95), increased gastric pH (5.82 vs. 3.98) (omeprazole = 4.63), elevated SOD and CAT levels (98.14 vs. 30.31, and 500.19 vs. 132.11 U/ml) (omeprazole = 70.44 and 362.42), decreased MDA levels (3.07 vs. 28.11 ng/ml) (omeprazole = 5.51), decreased ulcer index (0.31 vs. 7.19) (omeprazole = 2.63), increased parietal cell count (625.73 vs. 334.51 cell/mm) (omeprazole = 604.69), increased COX-1 immunostain percentage (25.28 vs. 10.92) (omeprazole = 17.46), lowered COX-2 and 5-LOX immunostain percentages (10.12 vs. 42.95, and 18.32 vs. 43.62) (omeprazole = 17.02 and 23.83). In conclusion, apigenin mitigates chronic gastric ulcer parameters via involvement of COX-1/2 and 5-LOX signaling pathways, having the upper hand over omeprazole.