Inhibition of 11 beta-hydroxysteroid dehydrogenase obtained from guinea pig kidney by some bioflavonoids and triterpenoids
Abstract
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
degrees 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 IC50 (95% confidence limits) values of glycyrrhizic acid,
naringenin, fisetin, emodin were 254 (202-320), 336 (270-418), 470 (392-564), and
527 (425-653) mumol.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.
Keywords:
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
degrees 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 IC50 (95% confidence limits) values of glycyrrhizic acid,
naringenin, fisetin, emodin were 254 (202-320), 336 (270-418), 470 (392-564), and
527 (425-653) mumol.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.