Treatment of arthritis and substances for use in such treatment

A method of treating the symptoms of arthritis comprising administering an effective amount of an anthraquinone derivative derived from one of the following formulae A and B ##STR3## in which formulae X is an --OH or a --NH.sub.2 group, in either of which there is a further substituent of at least one solubilising group selected from --(CH.sub.2).sub.n --COOH groups, --CHOH--(CH.sub.2).sub.n --COOH groups, --CO--(CH.sub.2).sub.n --COOH groups, --CH.sub.2 --O--(CH.sub.2).sub.n --COOH groups, --CH.sub.2 --O--CO --(CH.sub.2).sub.n --COOH groups, --O--(CH.sub.2).sub.n --COOH groups, --CH.sub.2 NH.sub.2 groups, --CH.sub.2 NHMe groups, --CH.sub.2 --NMe.sub.2 groups, --CH.sub.2 --NHEt groups, --CH.sub.2 --NEt.sub.2 groups, --SO.sub.3 H groups, --SO.sub.2 NH.sub.2 groups and pharmaceutically acceptable salts of such groups, wherein n is 0, or any integer not exceeding 10, and which may be substituted with no more than one additional hydroxyl group, or a pharmacological equivalent of a hydroxyl group, that must be in the 4,5 or 8 positions only, and in which there may be one or more inactive substituents selected from methyl, ethyl, propyl, butyl, methoxy and ethoxy groups, chlorine, bromine and iodine atoms, or the pharmacological equivalent of any such anthraquinone derivative.