ANTI-INFLAMMATORY EFFECT OF α—SPINASTEROL

a-Spinasterol was isolated from Bupleururn chinense DC. The compound was shown to suppress markedly the swelling of the hind paw induced by injection of carrageenin in intact and in adrenalectomized rats and mice. It also showed significant suppressive effects on scald oedema of the hind paw in rats and on proliferation of granulation tissue of croton oil induced air pouch granuloma in rats. Some inhibition of exudation of the granuloma pouch was also observed. In addition, α-spinasterol was found to significantly reduce the fever induced by se injection of 15% yeast suspension 20 ml/kg in rats. The ip LD₅₀ of α-spinasterol in mice was 478.8±9.28 mg/kg.Experimental results indicate that the mechanism of antiinflammatory effects of α-spinasterol is rather complicated. Marked inhibitory effects on synthysis or release of prostaglandin E (PGE) and bradykinin (BK) as well as on phlogistic effect of PGE2, BK, histamine and 5-HT were demonstrated. Inhibition of leucocyte migratory response was also observed. These actions of α-spinasterol seem not to be related to stimulation of the pituitary-adrenal axis. However, the weight of adrenal gland was increased significantly by ip of α-spinasterol 48 mg/kg once daily for 7 successive days.