Got ulcers? Fight it with arugula. Turns out that this salad add on helps reduce stomach-acid serotonin that can irritate gastric ulcers, the type of peptic ulcers that form in the abdominal wall and can cause severe pain. Arugula does more than stimulate liver health, it helps prevent cancer and it affects ulcer activity by limiting acid serotonin or by regulating hormones that ptotect the gastric-wall lining. Plus, it has high levels of antioxidants, which experts believe may contribute to its anti-ulcer properties.