Reduced protein oxidation in Wistar rats supplemented with marine ω3 PUFAs

• Published in: Free radical biology & medicine Vol. 55; pp. 8 - 20
• Main Authors: Méndez, Lucía, Pazos, Manuel, Gallardo, José M., Torres, Josep L., Pérez-Jiménez, Jara, Nogués, Rosa, Romeu, Marta, Medina, Isabel
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2013
• Subjects: actin; albumins; alpha-linolenic acid; Animals; antioxidant activity; blood proteins; Dietary intervention; Dietary Supplements; Docosahexaenoic acid; Docosahexaenoic Acids - pharmacology; Eicosapentaenoic acid; Eicosapentaenoic Acid - pharmacology; erythrocytes; fatty acid composition; Female; Fish oil; fish oils; fluorescein; free fatty acids; Free radicals; gels; kidneys; Linoleic acid; Linolenic acid; linseed; Linseed Oil - pharmacology; liver; nutritional intervention; oxidation; Oxidation-Reduction - drug effects; Oxidative stress; protective effect; Protein carbonylation; Proteins - chemistry; Proteins - metabolism; proteomics; Rats; Rats, Wistar; skeletal muscle; Soybean Oil - pharmacology; soybeans; vegetable oil; Wistar rats; GC/FID; Oxidative stress; Protein carbonylation; DTT; MDA; Docosahexaenoic acid; 1/2-DE; Wistar rats; ASS; AST; DNPH; Dietary intervention; Free radicals; PUFA; AKR; EDTA; SDS–PAGE; Fish oil; Linoleic acid; ARA; LC–ESI–IT–MS/MS; Linolenic acid; LA; ALA; EPA; ROS; DHA; Eicosapentaenoic acid; FTSC
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2012.11.004

The potential effects of various dietary eicosapentaenoic acid (EPA; 20:5) and docosahexaenoic acid (DHA; 22:6) ratios (1:1, 2:1, and 1:2, respectively) on protein redox states from plasma, kidney, skeletal muscle, and liver were investigated in Wistar rats. Dietary fish oil groups were compared with animals fed soybean and linseed oils, vegetable oils enriched in ω6 linoleic acid (LA; 18:2) and ω3 α-linolenic acid (ALA; 18:3), respectively. Fish oil treatments were effective at reducing the level of total fatty acids in plasma and enriching the plasmatic free fatty acid fraction and erythrocyte membranes in EPA and DHA. A proteomic approach consisting of fluorescein 5-thiosemicarbazide (FTSC) labeling of protein carbonyls, FTSC intensity visualization on 1-DE or 2-DE gels, and protein identification by MS/MS was used for the protein oxidation assessment. Albumin was found to be the most carbonylated protein in plasma for all dietary groups, and its oxidation level was significantly modulated by dietary interventions. Supplementation with an equal EPA:DHA ratio (1:1) showed the lowest oxidation score for plasma albumin, followed in increasing order of carbonylation by 1:2 <2:1 ≈ linseed < soybean. Oxidation patterns of myofibrillar skeletal muscle proteins and cytosolic proteins from kidney and liver also indicated a protective effect on proteins for the fish oil treatments, the 1:1 ratio exhibiting the lowest protein oxidation scores. The effect of fish oil treatments at reducing carbonylation on specific proteins from plasma (albumin), skeletal muscle (actin), and liver (albumin, argininosuccinate synthetase, 3-α-hydroxysteroid dehydrogenase) was remarkable. This investigation highlights the efficiency of dietary fish oil at reducing in vivo oxidative damage of proteins compared to oils enriched in the 18-carbon polyunsaturated fatty acids ω3 ALA and ω6 LA, and such antioxidant activity may differ among different fish oil sources because of variations in EPA/DHA content. [Display omitted] ► Fish oil diets reduce plasmatic total fatty acids compared to soybean oil. ► Fish oil treatments are effective at incorporating EPA and DHA into the tissues. ► Fish diets reduce protein oxidation in plasma, skeletal muscle, kidney, and liver. ► A ratio of 1:1 for EPA:DHA provides the highest antioxidant protection to proteins. ► We identified several proteins with strong redox regulation by dietary EPA/DHA.