Docosahexaenoic acid

About: Docosahexaenoic acid is a research topic. Over the lifetime, 14412 publications have been published within this topic receiving 620852 citations. The topic is also known as: all-cis-DHA & all-cis-docosa-4,7,10,13,16,19-hexaenoic acid.

Docosahexaenoic acid induces apoptosis in MCF-7 cells in vitro and in vivo via reactive oxygen species formation and caspase 8 activation.

Abstract: Background The present study sought to further investigate the in vitro and in vivo anticancer effects of a representative omega-3 fatty acid, docosahexaenoic acid (DHA), with a focus on assessing the induction of oxidative stress and apoptosis as an important mechanism for its anticancer actions. Methodology/Principal Findings In vitro studies showed that DHA strongly reduces the viability and DNA synthesis of MCF-7 human breast cancer cells in culture, and also promotes cell death via apoptosis. Mechanistically, accumulation of reactive oxygen species and activation of caspase 8 contribute critically to the induction of apoptotic cell death. Co-presence of antioxidants or selective inhibition or knockdown of caspase 8 each effectively abrogates the cytotoxic effect of DHA. Using athymic nude mice as an in vivo model, we found that feeding animals the 5% fish oil-supplemented diet for 6 weeks significantly reduces the growth of MCF-7 human breast cancer cells in vivo through inhibition of cancer cell proliferation as well as promotion of cell death. Using 3-nitrotyrosine as a parameter, we confirmed that the fish oil-supplemented diet significantly increases oxidative stress in tumor cells in vivo. Analysis of fatty acid content in plasma and tissues showed that feeding animals a 5% fish oil diet increases the levels of DHA and eicosapentaenoic acid in both normal and tumorous mammary tissues by 329% and 300%, respectively. Conclusions/Significance DHA can strongly induce apoptosis in human MCF-7 breast cancer cells both in vitro and in vivo. The induction of apoptosis in these cells is selectively mediated via caspase 8 activation. These observations call for further studies to assess the effectiveness of fish oil as a dietary supplement in the prevention and treatment of human breast cancer.

Fatty acid composition of oils from 21 species of marine fish, freshwater fish and shellfish.

Abstract: The fatty acid composition of body lipids was determined by GLC for 14 species of saltwater fish, three species of freshwater fish and four species of shellfish. In addition, liver lipids of two species and egg lipids of one species were analyzed for comparison with the fish body lipids. The various species ranged from lean to fatty and contained from 0.7~15.5% oil in the tissues. Certain major fatty acids were found to vary widely among the species, as follows: 1.6~8.0% myristic, 9.5~33.4% palmitic, 2.0~11.2% palmitoleic, 5.2~29.1% oleic, 0.7~10.5% eicosenoic, 5.0~21.5% eicosapentaenoic, 0.2~11.6% docosenoic and 5.9~26.2% docosahexaenoic acids. Analyses of two separate mullet-oil samples illustrated the wide differences that are possible for a single species caught during different seasons. Significant differences in the amt of particular fatty acids were found in comparing freshwater-fish analyses with analyses for marine fish. Oysters and scallops showed large amt of pentaenoic and hexaenoic acids in their oils.

Omega-3 Fatty Acids Improve Recovery, whereas Omega-6 Fatty Acids Worsen Outcome, after Spinal Cord Injury in the Adult Rat

Abstract: Spinal cord injury (SCI) is a cause of major neurological disability, and no satisfactory treatment is currently available. Evidence suggests that polyunsaturated fatty acids (PUFAs) could target some of the pathological mechanisms that underlie damage after SCI. We examined the effects of treatment with PUFAs after lateral spinal cord hemisection in the rat. The omega-3 PUFAs alpha-linolenic acid and docosahexaenoic acid (DHA) injected 30 min after injury induced significantly improved locomotor performance and neuroprotection, including decreased lesion size and apoptosis and increased neuronal and oligodendrocyte survival. Evidence showing a decrease in RNA/DNA oxidation suggests that the neuroprotective effect of omega-3 PUFAs involved a significant antioxidant function. In contrast, animals treated with arachidonic acid, an omega-6 PUFA, had a significantly worse outcome than controls. We confirmed the neuroprotective effect of omega-3 PUFAs by examining the effects of DHA treatment after spinal cord compression injury. Results indicated that DHA administered 30 min after spinal cord compression not only greatly increased survival of neurons but also resulted in significantly better locomotor performance for up to 6 weeks after injury. This report shows a striking difference in efficacy between the effects of treatment with omega-3 and omega-6 PUFAs on the outcome of SCI, with omega-3 PUFAs being neuroprotective and omega-6 PUFAs having a damaging effect. Given the proven clinical safety of omega-3 PUFAs, our observations show that these PUFAs have significant therapeutic potential in SCI. In contrast, the use of preparations enriched in omega-6 PUFAs after injury could worsen outcome after SCI.

Dietary supplementation of omega-3 polyunsaturated fatty acids improves insulin sensitivity in non-insulin-dependent diabetes.

Abstract: The effect of dietary omega-3 polyunsaturated fatty acids on the lipid composition and fluidity of erythrocyte membranes, and on in vivo insulin sensitivity was studied in 6 non-insulin-dependent diabetic (NIDD) patients. An 8 weeks daily supplementation of 3 g of the omega 3 fatty acids eicosapentaenoic and docosahexaenoic acid resulted in an increase of the membrane phospholipid unsaturation and the sphingomyelin content. Erythrocyte membrane fluidity, measured with electron spin resonance of intact erythrocytes and with fluorescence polarization of erythrocyte ghosts, did not change. The in vivo insulin stimulated glucose uptake was estimated by determining the metabolic clearance rate (MCR) of glucose in the steady state of a simultaneous infusion during 150 min of glucose (33 mumol/kg/min) and insulin (50 mU/kg/hr). The MCR of glucose increased in all patients; from 3.93 +/- 0.55 - 4.69 +/- 0.74 ml/kg/min (mean +/- SEM, p less than 0.05). Plasma triglyceride concentrations fell from 1.9 +/- 0.3 - 1.2 +/- 0.2 mmol/l (mean +/- SEM, p less than 0.05). We conclude that in NIDDs dietary supplementation of omega 3 fatty acids improves in vivo insulin sensitivity and lowers plasma triglyceride levels, while erythrocyte membrane fluidity remains unaltered.