Ethanol effects on lipid peroxidation and glutathione-mediated defense in rat small intestine: role of dietary fats.
The effect of ethanol feeding for 5 weeks on lipid peroxidation status of small intestine was studied in rats maintained on either a rat pellet (RP) or a semisynthetic diet containing coconut oil (CCO), corn oil (CO), or fish oil (FO). Highest rate of iron/ascorbate-induced lipid peroxidation was observed in intestinal mucosa of FO-fed rats, which was further elevated (p < 0.05) upon ethanol administration. Purified brush borders from all the ethanol-treated dietary groups were more susceptible to iron-induced lipid peroxidation. Level of nonprotein thiols was increased by ethanol feeding to rats given CO or FO. FO-fed rats exhibited increased activities of glutathione reductase (GR), glutathione-S-transferase (GST), and catalase (Cat). Glutathione peroxidase (GPx) was the lowest in the CCO group. Ethanol-treated FO group exhibited increased GST and GPx activities compared to controls, whereas in rats fed the RP or CO diet, ethanol feeding significantly decreased GST activity. GR and Cat activities were not affected under these conditions. Thus, ethanol exposes the small intestinal mucosa to oxidative stress. The effects were more pronounced in rats fed n-3 fatty acid-rich (FO) diet. The corresponding rise in GPx and GST levels may reflect the adaptive changes in intestine.
Kaur
M
M
Department of Biochemistry, Panjab University, Chandigarh, India.
Kaur
J
J
Ojha
S
S
Mahmood
A
A
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D002374:Catalase / Q000378:metabolism; D000074263:Coconut Oil; D003314:Corn Oil / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage*; D000431:Ethanol / Q000494:pharmacology*; D005395:Fish Oils / Q000008:administration & dosage; D005978:Glutathione / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism*; D007501:Iron / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D010938:Plant Oils / Q000008:administration & dosage; D051381:Rats; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D004041:Dietary Fats; D005395:Fish Oils; D010938:Plant Oils; D017392:Thiobarbituric Acid Reactive Substances; D000431:Ethanol; D003314:Corn Oil; D007501:Iron; D002374:Catalase; D005979:Glutathione Peroxidase; D005982:Glutathione Transferase; D005978:Glutathione; D001205:Ascorbic Acid; D000074263:Coconut Oil