Substituted 9-benzyladenines: inhibitors of inflammation associated with the delayed hypersensitivity skin reaction

Effect of nonsteroidal anti-inflammatory and other pharmacological agents on tuberculin reaction

Nonsteroidal anti-inflammatory and other pharmacological agents were tested in the efferent arc of the tuberculin skin reaction in the guinea pig. A low but significant inhibition was produced by the acidic anti-inflammatory agents, including the arylalkanoic acids, the anthranilic acids, indomethacin, and phenylbutazone. Some nonacidic anti-inflammatory agents also were inhibitory; benzydamine caused a high inhibition. Except for methotrexate, the antineoplastic--antimetabolite agents were not potent inhibitors. Inhibition without toxicity was produced by the coumarin anticoagulants, the diuretics, chloroquine, tilorone, and the following immunoregulators: antithymocyte gamma-globulin, cyclophosphamide, and penicillamine. Levamisole, colchicine, heparin, and niridazole were inhibitory but produced lethality either at or above the effective dose.

Structure-activity profile of substituted purines and inflammation in the delayed hypersensitivity skin reaction

Substituted purines were tested for their effectiveness in inhibiting the delayed hypersensitivity skin reaction (DHSR) caused by tuberculin in the guinea-pig. Among the tested purines were naturally occurring derivatives of guanine and adenine, including cyclic AMP. Based on the structure-activity profile, a class of purines was identified, the members of which were very effective inhibitors of inflammatory aspects of the DHSR and are characterized by a benzyl group in position 9, an amino or alkylamino group in position 6, and various substituents in position 2. This class of 2-substituted-9-benzyladenines was more effective in the DHSR than some antimetabolites, particularly the structurally related mercaptopurines.