Dietary docosahexaenoic acid does not promote tissue lipid peroxide formation to the extent expected from the peroxidizability index of the lipids

Abstract

Changes in susceptibility of tissues to lipid peroxidation were investigated in rats after ingestion of oxidation-prone docosahexaenoic acid (C22:6n-3). Lipid peroxide levels in the liver, kidney and testis increased concomitant with increases in the peroxidizability indices calculated from the fatty acid composition of tissue total lipids. However, even in these cases, the lipid peroxides were not increased to the levels expected from the peroxidizability indices of these tissues, and thus no tissue injury was recognized. When low level of vitamin E was given to rats, the lipid peroxide levels of liver, kidney and testis nearly coincided with the peroxidizability indices of these tissues, where the cell injuries were observed as well. The mechanisms of defense to suppress lipid peroxide levels below the peroxidizability indices in normal vitamin E administration were presumed to be due to enhanced antioxidative function in the tissues mediated primarily by vitamin E, ascorbic acid and glutathione, and also to increased incorporation of docosahexaenoic acid into neutral lipids and phosphatidylethanolamine in the tissues, probably leading to acquiring stability against oxidative attack. Owing to these suppressive mechanisms, physiological efficacy of n-3 fatty acids may be exerted effectively.

Addition of docosahexaenoic acid, but not arachidonic acid, activates glutathione and thioredoxin antioxidant systems in murine hippocampal HT22 cells: potential implications in neuroprotection

“…Remarkably, HHE levels were very low even at 48 h supplementation with DHA and, in fact, we have no evidence of significant phospholipid peroxidation, even though the peroxidablity index calculated for DHA‐treated samples increased by more than two‐fold compared to BSA‐treated cells. In agreement with our results, several studies have point out that dietary supplementation with DHA does not promote tissue lipid peroxide formation to the extent expected from the peroxidablity values of lipids in different organs from rats (Saito ; Saito and Kubo ). Overall, these data indicates that DHA (or its oxidized metabolites) triggers the activation of antioxidant mechanisms to control the progression of oxidative damage and to neutralize the generation of lipid peroxides.…”

Carnosine Alleviates Knee Osteoarthritis and Promotes Synoviocyte Protection via Activating the Nrf2/HO-1 Signaling Pathway: An In-Vivo and In-Vitro Study

“…The levels of oxidative stress related biomarkers were estimated using the previous protocols [ 56 ]. In all groups, all parameters were checked in the knee OA tissue samples.…”

More than Just Wine: The Nutritional Benefits of Grapevine Leaves

“…Although it is described in the literature that the higher the PI values, the greater the susceptibility to lipid peroxidation, Min Jeong Kang and co-workers proved that a high polyunsaturated/saturated fatty acid ratio diet has a beneficial effect on cardiovascular disease risk even without antioxidant when the PI value is the same, above 80 [78]. This is because a high P/S ratio diet makes it difficult to increase lipid peroxidation because of the high concentrations of PUFA [79]. There are very few studies about what the optimal PI value might be hence further studies are encouraged to evaluate this index in the everyday diet.…”