This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Jhee, E.-C. Articles by Lotlikar, P. D. Search for Related Content PubMed PubMed Citation Articles by Jhee, E.-C. Articles by Lotlikar, P. D.

Effect of Butylated Hydroxyanisole Pretreatment on Aflatoxin B₁-DNA Binding and Aflatoxin B₁-Glutathione Conjugation in Isolated Hepatocytes from Rats¹

Fels Research Institute, Temple University School of Medicine, Philadelphia, Pennsylvania 19140

The effect of 2(3)-tert-butyl-4-hydroxyanisole (BHA) pretreatment of rats on both aflatoxin B₁ (AFB₁)-DNA binding and AFB₁-glutathione has been examined with isolated hepatocytes and in intact rats. Young male F344 rats were fed AIN-76A diet with or without 0.75% BHA for 2 weeks. Even though there were no significant differences in either cytochrome P-450 or reduced glutathione contents, there were marked differences in AFB₁ metabolism in isolated hepatocytes from these two groups. Thus, at the 33 nM AFB₁ level, AFB₁-DNA binding was 3-fold higher in control compared to BHA-treated hepatocytes whereas AFB₁-glutathione conjugation was 5-fold higher in treated compared to controls. Even at higher AFB₁ concentrations (2 and 10 µM), DNA binding was 4–6-fold higher in controls whereas thiol conjugation was 5–9-fold higher in treated compared to control hepatocytes. Addition of 0.5–1.0 mM diethylmaleate did not have any significant effect in control hepatocytes whereas its presence produced about 70–100% increase in DNA binding with 65–80% inhibition of thiol conjugation in treated hepatocytes. Addition of 1 mM styrene oxide caused 75–100% and 4–8-fold increase in AFB₁-DNA binding in control and treated hepatocytes, respectively, with corresponding decreases in thiol conjugation. In intact rats, BHA treatment reduced hepatic AFB₁-DNA binding to 15% of controls with concomitant increase in biliary excretion of AFB₁-reduced glutathione conjugate. It appears that the induced cytosolic GSH S-transferases after BHA treatment of rats play a significant role in inhibiting hepatic AFB₁-DNA binding and AFB₁ hepatocarcinogenesis presumably by inactivation of the reactive AFB₁-epoxide.

¹ This paper is dedicated to Dr. Sidney Weinhouse with deep appreciation and gratitude on the occasion of his 80th birthday.

Supported by Grants CA-40855 and CA-1227 and Training Grant CA-09214 (P. G., a trainee on this grant) from the National Cancer Institute, Department of Health and Human Services; by Grant SIG-6 from the American Cancer Society; and the Samuel S. Fels Fund of Philadelphia. A preliminary report on this work has appeared recently (46).

² Present address: Department of Biochemistry, ChonBuk National University, College of Dentistry, Chonju, Korea, 560-020.

³ To whom requests for reprints should be addressed.

Received 9/ 8/88. Revised 12/ 9/88. Accepted 12/19/88.