Pharmacological study of Kako-bushi-matsu: Analgesic action and acute toxicity.

The analgesic effect and the acute toxicity of a medical drug "kako-bushi-matsu" (S-01), which was produced through several processing of raw aconite roots, were examined in comparison with those of ibuprofen, indomethacin and aspirin. S-01 (p.o.) inhibited the acetic acid- and phenylquinone-induced writhing dose-dependently. From the ED50 values, indomethacin showed more potent inhibitory action on the phenylquinone-induced writhing than on the acetic acid-induced writhing. Ibuprofen and aspirin showed the same tendency as indomethacin. The potency of the writhing inhibition by S-01 was almost to the same degree in both writhing methods. In the tail pressure method, S-01 raised the pain threshold ratio to almost the same degree as ibuprofen did. In Randall-Selitto's method, the analgesic effect of S-01 on inflamed foot was less than that of ibuprofen. In the normal foot, S-01 raised the pain threshold ratio dose-dependently, but ibuprofen did not influence the pain threshold ratio. On adjuvant-induced arthritic pain, S-01 and ibuprofen had an analgesic action, and this action of S-01 was less than that of ibuprofen. The oral LD50 value of S-01 was more than 10,000 mg/kg in mice and rats of both sexes. The above evidence indicates that S-01 has analgesic action and suggests that the mode of the analgesic action of S-01 may differ from those of ibuprofen, indomethacin and aspirin, which inhibit prostaglandin biosynthesis.