Original Article

The Effects of Vitamin B Complexes on AAF Hydroxylation by Rat Liver Microsomal Cytochrome P-450

Young Sook Hong, Bok Hoi Kim, Nak Eung Sung
Author Information & Copyright
Department of Biochemistry, School of Medicine, Ewha womans University, Korea.
Corresponding author: Nak Eung Sung. Department of Biochemistry, School of Medicine, Ewha Womans University, Korea.

Copyright ⓒ 1980. Ewha Womans University School of Medicine. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Published Online: Jul 24, 2015

Abstract

The effects of vitamin B complexes on both ring and N-hydroxylation of 2-ace-tylaminofluorene by rat hepatic microsomal fraction were studied.

In the presence of thiamine-Hcl during incubation, the total hydroxy-AAF was increased by 50.3%. 0.1mM and 1.0mM riboflavin inhibited only total hydroxy-AAF with 56.7% and 85.0 whereas N-hydroxy AAF was increased to some extent. 1.0mM niacin did not have much effect on the total hydroxy-AAF, but 0.1mM niacin decreased the total dydroxy-AAF by 28.6%. Presence of p-amino-benzoic acid, calcium pantothenate, pyridoxal-Hcl or vitamin B12 inhibited the total hydroxy-AAF to some extent. But the radio of ring-and N-AAF hydroxylation was not changed by these vitaminn B complexes.

Our present results suggest that vitamin B complexes were not effective in vitro metabolism of 2-AAF to N-hydroxy AAF(activation step of AAF) by a cytochrome p-450 dependent mixed function oxidase system.