TNF and ulcerative colitis: In a study, it was discovered that psoralen (5, 10, 20 mg/kg), a coumarin component isolated from PCL, could, in a dose-dependent manner, lower the expression of IL-6, IL-1, and TNF-inflammatory factors in serum and colonic tissues of mice with ulcerative colitis and reduce inflammatory cell infiltration, and had a positive therapeutic effect on the ulcerative colitis in mice that was brought on by dextran sodium sulfate [77].