Remedies or preventives containing cyclopentenone compounds as the active ingredient

A method for treating or preventing a disease that requires immunoregulation for its treatment or prevention, a disease that requires suppression of inflammation for its treatment or prevention, a disease that requires inhibition of tumor necrosis factor production for its treatment or prevention, a disease that requires inhibition of a fungus for its treatment or prevention, a disease that requires inhibition of cell adhesion for its treatment or prevention, a disease that requires activation of NK cells for its treatment or prevention or a disease that requires induction of heat shock protein for its treatment or prevention, the method comprising

• administering to a subject in need thereof a pharmaceutical composition which contains as an active ingredient, in an amount sufficient therefor, of at least one compound of formula (I):
• wherein R1 and R2 may be identical or different from each other, and are hydrogen, an aliphatic group, an aromatic group or an aromatic aliphatic group, or an optical isomer or salt thereof.