The present invention provides a TNF-.alpha. production inhibitor
containing a kavalactone as an active ingredient, which inhibitor has
high safety, exerts an excellent effect of inhibiting TNF-.alpha.
production, and is useful as a drug or an animal drug for preventing,
ameliorating, or treating diseases such as cachexia attributed to cancer
or infectious diseases, chronic rheumatoid arthritis, inflammatory
diseases, osteoarthritis, systemic lupus erythematosus (SLE), rejection
during bone marrow transplantation, multiple organ failure, AIDS,
meningitis, hepatitis, and type-II diabetes. The present invention also
provides a preventive, ameliorating, or therapeutic agent for diseases
caused by abnormal production of TNF-.alpha., the agent containing a
kavalactone as an active ingredient.