[Anti-inflammatory, analgesic and antipyretic activities of alpha-(p-thenoylphenyl)-propionic acid (TN-762) (author's transl)].

We reported in our previous paper that TN-762, a potent inhibitor of prostaglandin biosynthesis, has marked inhibitory activity on acute experimental inflammation. In this paper, the anti-inflammatory, analgesic, and antipyretic activities of TN-762 were assessed in animal models, and compared with those of indomethacin, ketoprofen and ibuprofen. TN-762 inhibited the sustained paw edema induced by mustard in rats during administration for 3 days, but after final administration, the inhibitory activity was decreased rapidly and was less then that of ketoprofen and indomethacin. TN-762 also inhibited the proliferation of granuloma induced by means of cotton pellet and granuloma pouch methods, and the adjuvant arthritis in rats. The inhibitory activity of the compound on inflammatory proliferation was more potent than that of ibuprofen, but slightly less than that of ketoprofen and less than about 1/10 times that of indomethacin. Indomethacin markedly inhibited the body weight gain at a high dose, while TN-762 did not affect it. Therefore, TN-762 was proven to have an inhibitory effect on subacute and chronic inflammation at low doses without toxic effects, but the compound appeared to have a less of an inhibitory effect on secondary or late stages of inflammation than on primary stage inflammation. TN-762 inhibited the acute paw edema induced by nystatin, and the inhibitory activity was the same as that of ketoprofen and indomethacin. The pathogenesis of nystatin edema has been considered to be due to lysosomal labilization. This result suggests that TN-762 has a potent membrane stabilizing action which is considered to be one of the necessary mechanisms in anti-inflammatory action. On the other hand, TN-762 showed the same potent analgesic effect as ketoprofen and indomethacin as observed by the acetic acid writhing and modified Haffner's methods in mice and by the Randall-Selitto's method in rats. However the antipyretic effect of TN-762 was significantly less than that of ketoprofen and indomethacin.