TNF and brain inflammatory disease: Administration of icariin (30, 60, 120 mg/kg/day) for 17 consecutive days increased spatial learning and memory and reduced tumor necrosis factor-α (TNF-α), interleukin-1(IL1) and cyclooxygenase-2 (COX-2) expression in a rat model with brain inflammation induced by lipopolysaccharide (LPS) [35].