Dietary docosahexaenoic acid has little effect on peroxisomes in healthy mice

Evolutionary History of Rhus chinensis (Anacardiaceae) From the Temperate and Subtropical Zones of China Based on cpDNA and Nuclear DNA Sequences and Ecological Niche Model

To explore the origin and evolution of local flora and vegetation, we examined the evolutionary history of Rhus chinensis, which is widely distributed in China’s temperate and subtropical zones, by sequencing three maternally inherited chloroplast DNAs (cpDNA: trnL-trnF, psbA-trnH, and rbcL) and the biparentally inherited nuclear DNA (nuDNA: LEAFY) from 19 natural populations of R. chinensis as well as the ecological niche modeling. In all, 23 chloroplast haplotypes (M1–M23) and 15 nuclear alleles (N1–N15) were detected. The estimation of divergence time showed that the most recent common ancestor dated at 4.2 ± 2.5 million years ago (Mya) from cpDNA, and the initial divergence of genotypes occurred at 4.8 ± 3.6 Mya for the nuDNA. Meanwhile, the multimodality mismatch distribution curves and positive Tajima’s D values indicated that R. chinensis did not experience population expansion after the last glacial maximum. Besides, our study was also consistent with the hypothesis that most refugia in the temperate and subtropical zones of China were in situ during the glaciation.

In vitro effects of selenite and mercuric chloride on liver thiobarbituric acid-reactive substances and non-protein thiols from rats: influences of dietary cholesterol and polyunsaturated and saturated fatty acids

OBJECTIVE

We measured the in vitro effects of mercuric chloride (Hg2+) and selenite (Se4+) on hepatic 2-thiobarbituric acid-reactive substances (TBARS) and non-protein sulfhydryl (NPSH) levels of rats fed diets enriched with polyunsaturated or saturated fatty acids with and without cholesterol.

METHODS

Male Wistar rats (21 d old) were assigned to one of four groups and fed diets containing 20% soybean oil, 20% soybean oil plus 1% cholesterol, 20% coconut oil, or coconut oil plus 1% cholesterol. After the feeding period (6 wk), body weight gain was equal in all groups. TBARS levels and NPSH content were measured after in vitro exposure to mercuric chloride (100 microM) and sodium selenite (25 microM) for 1 h.

RESULTS

The lipid peroxidation, measured as TBARS levels in the control group, were statistically higher in hepatic homogenates of rats fed diets containing soybean oil than in groups fed coconut oil (P = 0.009). However, cholesterol supplementation did not change TBARS levels. Selenite alone did not modify TBARS production, whereas mercury alone significantly increased TBARS levels. Moreover, Se4+ protected against mercury-induced lipid peroxidation only in rats fed diets containing coconut oil. In the control group, dietary fat acids did not change NPSH levels. Selenite produced higher oxidative effects toward NPSH content, whereas Hg2+ decreased NPSH levels only in liver from rats fed diets containing soybean oil. NPSH levels were higher after concomitant exposure to Se4+ and Hg2+ chloride that after exposure to Se4+ alone, suggesting an interaction between Hg2+ and Se4+. Catalase activity was higher in animals fed diets containing soybean oil. Dietary cholesterol decreased glutathione peroxidase activity.

CONCLUSION

Together these results indicated that the protective effect of Se4+ against mercury-induced lipid peroxidation depends on dietary fat saturation.

Secondary carnitine deficiency and impaired docosahexaenoic (22:6n-3) acid synthesis: a common denominator in the pathophysiology of diseases of oxidative phosphorylation and beta-oxidation

A critical analysis of the literature of mitochondrial disorders reveals that genetic diseases of oxidative phosphorylation are often associated with impaired beta-oxidation, and vice versa, and preferentially affect brain, retina, heart and skeletal muscle, tissues which depend on docosahexaenoic (22:6n-3)-containing phospholipids for functionality. Evidence suggests that an increased NADH/NAD(+) ratio generated by reduced flux through the respiratory chain inhibits beta-oxidation, producing secondary carnitine deficiency while increasing reactive oxygen species and depleting alpha-tocopherol (alpha-TOC). These events result in impairment of the recently elucidated mitochondrial pathway for synthesis of 22:6n-3-containing phospholipids, since carnitine and alpha-TOC are involved in their biosynthesis. Therapeutic supplementation with 22:6n-3 and alpha-TOC is suggested.

Fat intake and fatty acid profile in plasma phospholipids and adipose tissue in patients with Crohn's disease, compared with controls

OBJECTIVES

Fatty acid metabolism is involved in the immune response and inflammation processes in patients with Crohn's disease (CD). Fatty acid changes may be relevant to the clinical course of the disease. The aim of this study was to compare the qualitative and quantitative fat intake and fatty acid composition of plasma phospholipids and adipose tissue in a defined population of CD patients with those in matched controls.

METHODS

Dietary fat intake and fatty acid profile of plasma phospholipids and adipose tissue were assessed in two patient populations: 20 patients with recently diagnosed CD and 32 patients with longstanding (> 10 yr) CD clinically in remission, matched for age and gender with healthy controls.

RESULTS

We observed no significant differences in quantitative or qualitative fat intake between CD patients and controls. Percentages of linoleic acid and alpha-linolenic acid in plasma phospholipids or adipose tissue were not significantly different between patients and controls. However, we observed a significantly (p < 0.05) lower percentage of the sum of the n-3 fatty acids, with significantly (p < 0.01) higher levels of clupanodonic acid (22:5n-3) and significantly (p < 0.05) lower levels of docosahexaenoic (22:6n-3) and arachidonic acid (20:4n-6). The aberrant fatty acid profile was more evident in patients with longstanding CD than in patients with recently diagnosed CD.

CONCLUSION

The aberrant fatty acid profile found in these CD patients is a result of altered metabolism rather than of essential fatty acid malabsorption. The reported findings may be important in the pathophysiology of CD and hence in the choice of fatty acids to be used when therapeutic supplementation is considered in CD patients.