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 (DHA) blunts liver injury by conversion to protective lipid mediators: protectin D1 and 17S-hydroxy-DHA

Abstract: Docosahexaenoic acid (DHA) is a omega-3 essential fatty acid that reduces the incidence and severity of a number of diseases. Recently, a novel series of DHA-derived lipid mediators with potent protective actions has been identified. In this study we demonstrate that dietary amplification of these DHA-derived products protects the liver from necroinflammatory injury. In vitro, supplementation of hepatocytes with DHA significantly reduced hydrogen peroxide-induced DNA damage, evaluated by the "comet assay," and oxidative stress, determined by measurement of malondialdehyde levels. In vivo, dietary supplementation of mice with DHA ameliorated carbon tetrachloride-induced necroinflammatory damage. In addition, hepatic cyclooxygenase-2 expression and PGE2 levels were significantly reduced in mice fed DHA-enriched diets. In these animals, increased hepatic formation of DHA-derived lipid mediators (i.e., 17S-hydroxy-DHA (17S-HDHA) and protectin D1) was detected by HPLC-gas chromatography/mass spectrometry analysis. Consistent with these findings, synthetic 17-HDHA abrogated genotoxic and oxidative damage in hepatocytes and decreased TNF-alpha release and 5-lipoxygenase expression in macrophages. In a transactivation assay, 17-HDHA acted in a concentration-dependent manner as a PPARgamma agonist. Taken together, these findings identify a potential role for DHA-derived products, specifically 17S-HDHA and protectin D1, in mediating the protective effects of dietary DHA in necroinflammatory liver injury.

Effect of long-term fish oil supplementation on vitamin e status and lipid peroxidation in women

Abstract: Fifteen young (22-35 y) and 10 older (51-71 y) women received six capsules of fish oil (Pro-Mega)/d, providing a total of 1,680 mg eicosapentaenoic (EPA), 720 mg docosahexaenoic (DHA), 600 mg other fatty acids, and 6 IU vitamin E. Blood was collected before and after 1, 2 and 3 mo of supplementation. Compliance was confirmed by the significant increase in plasma EPA and DHA in all women. Older women had a significantly higher increase in EPA and DHA than did young women (10-fold increases in EPA and 2.5-fold increases in DHA vs. 8-fold in EPA and 2-fold in DHA for older and young women, respectively). The decrease in the arachidonic acid:EPA ratio was more dramatic in the older women. Plasma total triglycerides (TG) decreased significantly, and the ratio of polyunsaturated fatty acids to saturated fatty acids was significantly (P less than 0.01) increased. Plasma vitamin E levels did not change significantly after supplementation; however, after 3 mo of supplementation by young women, plasma vitamin E was significantly lower than after 1 mo. The vitamin E: TG ratio was significantly increased and vitamin E:(EPA + DHA) significantly decreased. All women showed a significant increase in plasma lipid peroxide through mo 2 of supplementation. After 2 mo, older women had significantly higher lipid peroxide levels than young women. The lipid peroxide:TG ratio, which declined by mo 3, was still significantly higher than baseline. These data indicate that although long-term fish oil supplementation may be beneficial in reducing plasma total TG, susceptibility of plasma lipids to free radical attack is potentiated.(ABSTRACT TRUNCATED AT 250 WORDS)