Cytotoxicity of flutamide and 2-hydroxyflutamide and their effects on CYP1A2 mRNA in primary rat hepatocytes.
OBJECTIVE
To compare the cytotoxicity of flutamide and its active metabolite 2-hydroxyflutamide and their effects on cytochrome P-450 1A2 mRNA in primary rat hepatocytes.


METHODS
After the isolation of hepatocytes a nd t he primary incubation for 4 h, flutamide and 2-hydroxyflutamide were added respectively to the medium at the concentration of 10, 20, and 50 mg/L and incubated for 8 h. Cytotoxicity of hepatocytes was assessed by Trypan blue exclusion, lactate dehydrogenase (LDH) leakage, percentage of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) release, and reduced glutathione (GSH). The effect of flutamide and 2-flutamide on the CYP1A2 mRNA level was further analyzed by Northern blot.


RESULTS
After incubation for 8 h, cell viability was observed by Trypan blue exclusion. The increase of ALT and AST activity and the decrease of glutathione content were also noted at 10, 20, and 50 mg/L of flutamide and 50 mg/L of 2-hydroxyflutamide as compared with normal rat hepatocytes. Induction of CYP1A 2 mRNA were 2-, 5-, and 7.5-fold at 10, 20, and 50 mg/L of flutamide and 3.5-fold at 50 mg/L of 2-hydroxyflutamide.


CONCLUSIONS
Cytotoxicity of flutamide and its effect on CYP1A2 mRNA were stronger than those of its active metabolite 2-hydroxyflutamide in primary rat hepatocytes.
Wang
Hai-Xue
HX
Department of Pharmacology, School of Pharmacy, Fudan University, Shanghai 20 0032, China.
Ma
Xiao-Chao
XC
Deng
Qiao-Lin
QL
Li
Duan
D
D000726:Androgen Antagonists / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D019388:Cytochrome P-450 CYP1A2 / Q000096:biosynthesis* / Q000235:genetics; D005485:Flutamide / Q000031:analogs & derivatives* / Q000494:pharmacology*; D022781:Hepatocytes / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley
D000726:Androgen Antagonists; D012333:RNA, Messenger; C014290:hydroxyflutamide; D005485:Flutamide; D019388:Cytochrome P-450 CYP1A2