Inhibition of 11 beta-hydroxysteroid dehydrogenase obtained from guinea pig kidney by some bioflavonoids and triterpenoids
Zhang, Y.D.; Wang, M.S.
Zhongguo Yao Li Xue Bao 18(3): 240-244
1997
ISSN/ISBN: 0253-9756 PMID: 10072942 Document Number: 477104
AIM: To study the inhibitory effect of some bioflavonoids and triterpenoids on 11-beta-hydroxysteroid dehydrogenase (11-beta-OHSD) from guinea pig kidney. METHOD: The 11-beta-OHSD of kidney cortex microsomes in addition of cortisol was incubated in the presence of NADP, Triton DF-18, and the test compounds at 37 degree C for 1 h. The enzyme activity was assayed by measuring the rate of conversion of cortisol to cortisone eluted with HPLC gradient analysis. RESULTS: The IC-50 (95% confidence limits) values of glycyrrhizic acid, naringenin, fisetin, emodin were 254 (202 - 320), 336 (270 - 418), 470 (392 - 564), and 527 (425 - 653) mu-mol cntdot L-1, respectively. The inhibitory effect of oleanolic acid was 2-fold stronger than that of astramembranin I. The mode of action of naringenin was competitive inhibition. CONCLUSION: The test compounds inhibited the 11-beta-OHSD in kidney cortex with different potencies as glycyrrhizic acid did.