RT Journal Article
SR Electronic
T1 Mechanism for inhibitory effect of cannabidiol on microsomal testosterone oxidation in male rat liver.
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 880
OP 889
VO 16
IS 6
A1 S Narimatsu
A1 K Watanabe
A1 I Yamamoto
A1 H Yoshimura
YR 1988
UL http://dmd.aspetjournals.org/content/16/6/880.abstract
AB Effects of four cannabinoids [cannabidiol (CBD), delta 8-tetrahydrocannabinol, delta 9-tetrahydrocannabinol, and cannabinol] on hepatic microsomal oxidation of testosterone (17 beta-hydroxy-androst-4-ene-3-one) were examined in adult male rats. Only CBD (30 microM) competitively inhibited 2 alpha-hydroxy-testosterone (2 alpha-OH-T) and 16 alpha-OH-T formation by hepatic microsomes but did not affect androstenedione (androst-4-ene-3,17-dione) and 7 alpha-OH-T formation. Kinetic analyses demonstrated that the inhibitory profile of CBD for testosterone oxidation was different from those of SKF 525-A, which caused competitive inhibition for 2 alpha- and 16 alpha-hydroxylations and noncompetitive inhibition for 6 alpha-hydroxylation, and of metyrapone, which inhibited only 6 beta-hydroxylation competitively. CBD also suppressed formation of 2 alpha-OH-T, 16 alpha-OH-T, and androstenedione from testosterone, catalyzed by a reconstituted system containing hepatic cytochrome P-450 purified from phenobarbital-treated rats. Pretreatment of the rat with CBD (10 mg/kg, ip, once a day for 3 days) decreased testosterone oxidation at the 2 alpha-, 16 alpha-, and 17-positions and increased 7 alpha-OH-T formation, while total cytochrome P-450 content was decreased. These results suggest that CBD suppresses hepatic testosterone oxidation at the 2 alpha-, 16 alpha-, and 17-positions through selective inhibition of the male-specific cytochrome P-450 in the adult male rat.