Inhibitory Effects of Hydrangenol Derivatives on the Activation of Hyaluronidase and their Antiallergic Activities

Antiallergic drugs such as disodium cromoglycate (DSCG) and tranilast are strong inhibitors of hyaluronidase. On developing new active antiallergic agents, we aimed principally at the inhibitory effects of hydrangenol derivatives on the activation of hyaluronidase. Among the compounds tested, the hydrangenol derivatives, BT-1 and BT-2, showed strong inhibitory effects. Antiallergic activities of BT-1 and BT-2 were also evident from the fact that they inhibited the histamine release from rat peritoneal mast cells induced by antigen and compound 48/80, and from the suppressive effect on 48 h homologous passive cutaneous anaphylaxis (PCA) in rats.