A method of treating one or more diseases caused by abnormal production of TNF-α in a patient in need thereof, wherein said disease is selected from the group consisting of cachexia related to infectious disease, septic shock, chronic rheumatoid arthritis, ulcerative colitis, Crohn disease, osteoarthritis, Kawasaki's disease, multiple sclerosis, Behchet's disease, systemic lupus erythematosus, rejection during bone marrow transplantation, multiple organ failure, malaria, AIDS, meningitis, hepatitis, and type-II diabetes, comprising administering to said patient in need thereof an effective dose of a kavalactone selected from the group consisting of methysticin, yangonin, and dihydrokavain.