Abstract: This invention relates to combinations, compositions, and methods using or having a substituted dialkyl ether, substituted aryl-alkyl ether, substituted dialkyl thioether, substituted dialkyl ketone, or substituted-alkyl compound, or a pharmaceutically acceptable salt thereof, as an active component for preventing or treating osteoarthritis, preventing or inhibiting cartilage damage, preventing or treating rheumatoid arthritis, improving joint function, alleviating pain, and the like in a patient in need thereof.