Anti-inflammatory effect of saikogenin A.
Saikogenin A, an anti-inflammatory drug, is present in the crude extract of a Chinese herbal plant called Tsai-Fu. Saikogenin A was less effective in adrenalectomized rats than in normal rats in reducing the carrageenin-induced edema. Serum corticosterone and ACTH were increased in the saikogenin A-treated rats, supporting the view that stimulation of hypothalamopituitary-adrenal system is responsible for the anti-inflammatory effect of saikogenin A. This is further supported by the findings that saikogenin A did not affect the spontaneous release of corticosterone but it facilitated the ACTH-induced release. In addition, cyclic AMP in isolated pituitary and adrenal glands was increased by saikogenin A. A role for cyclic AMP as the second messenger is thus considered. Otherwise, the direct action of saikogenin A on the process of inflammation cannot be ruled out because saikogenin A also functioned in the adrenalectomized rats and it inhibited the release of histamine induced by compound 48/80. Reduction of the vascular permeability was also observed in the saikogenin A-treated rats. These results suggest that the anti-inflammatory action of saikogenin A are due to an increase in corticosterone caused by the release of ACTH and a direct effect on the process of inflammation.
D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002199:Capillary Permeability / Q000187:drug effects; D002351:Carrageenan; D003345:Corticosterone / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis; D004487:Edema / Q000188:drug therapy; D005260:Female; D006636:Histamine Release / Q000187:drug effects; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D009828:Oleanolic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012502:Sapogenins / Q000494:pharmacology*
D000893:Anti-Inflammatory Agents; D012502:Sapogenins; C009198:saikogenin A; D009828:Oleanolic Acid; D002351:Carrageenan; D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP; D003345:Corticosterone; D007213:Indomethacin