• Applied Microscopy
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• v.27 no.2
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• pp.197-215
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• 1997

A morphologic study on the effect of butylated hydroxytoluene (BHT) on experimental hepatocarcinogenesis induced by 3'-methyl-4-dimethyl aminoazobenzene (3'-MeDAB) was investigated. A total of 110 Sprague-Dowley male rats weighting about 200 g each were used for the experiment, and divided into 4 groups; the 3'-MeDAB, BHT, 3'-MeDAB/BHT treated group, and the control group. Four to eight rats of each group were sacrified on the 4th, 8th, 14th and 16th experimental weeks, with continuous pelletized feeding containing 0.09% 3'-MeDAB and 0.5% BHT. The liver was examined by transmission and scanning electron microscopy. The results were as follows; Electron microscopically, the fine structure of the hepatocytes remained consistently abnormal up to 16 weeks after the 3'-MeDAB treatment. There was no significant difference in the groups observed earlier than in the ones observed later. Many subcellular changes were observed : nuclear change, decreased glycogen, mitochondrial abnormalities, disaggregated rough endoplasmic reticulum, marked proliferation of smooth endoplasmic reticulum, dilatation and distortion of bile canaliculi, increased lysosomes, apoptotic bodies, migration of bile ductule cell. In the BHT treated group, the ultrastructural changes of hepatocytes were not significant, except for the lipid droplets and proliferated smooth endoplasmic reticulum among hepatocytes depending on the experimental duration. The various subcellular changes of 3'-MeDAB/BHT treated groups were simillar to those of the 3'-MeDAB treated group, but the degree of changes in the 3'-MeDAB/ BHT treated group decreased compared with those of the 3'-MeDAB treated group. These results suggest that dietary butylated hydroxytoluene has a protective/inhibitory effect on the hepatocarcinogenesis induced by 3'-methyl-4-dimethyl -aminoazobenzene.

• Toxicological Research
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• v.11 no.2
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• pp.215-221
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• 1995

This paper examines the effects of dietary polyunsaturated fatty acid/saturated fatty acid (p/s) ratios and butylated hydroxytoluene (BHT) on the hepatic microsomaI mixed-function oxidase sy. stem in 2~acetylaminofiuorene (2-AAF) treated rats. Sprague-Dawley male rats were fed the diet of beef tallow (p/s 0.08), beef tallow plus soybean oil (p/s 1.0), and soybean oil (p/s 4.0) at the level of 15%fat and with or without 0.3% BHT. After 2-AAF was injected twice at the ages of 23 and 27 weeks, cholesterol/phospholipid molar ratio, thiobarbituric acid reactive substances (TBARS) level, cytochrome P450, cytochrome $b_5$, NADPH-cytochrome $b_5$, and NADPH-cytochrome c reductase activity were measured from isolated hepatic microsomal fractions. In the beef tallow (p/s 0.08) and beef tallow plus soybean oil (p/s 1.0) groups, cholesterol/phospholipid molar ratio showed decreasing tendency by 2-AAF and BHT. Cytochrome P-450 content was decreased in the group of soybean oil (p/s 4.0) and NADPH-cytochrome c reductase activity was increased by 2-AAF and BHT in all the dietary groups. While TBARS levels were increased by 2-AAF in all the dietary groups, they were reduced by BHT in the soybean oil (p/s 4.0) group. These results suggest that long term intake of soybean oil (p/s 4.0) diet induced changes in the nature of microsomal membrane and induced less cytochrome P-450, low level feeding of BHT increased cytochrome c reductase activity and lowered microsomal lipid peroxidation levels, which were increased by 2-AAF treatment.