Peroxisome proliferators enhance linoleic acid metabolism in rat liver. Increased biosynthesis of omega 6 polyunsaturated fatty acids.

The International Scientific Association for Probiotics and Prebiotics (ISAPP), in its last consensus statement about prebiotics, defined polyunsaturated fatty acids (PUFAs) as “candidate prebiotics” due to a lack of complete scientific evidence. Previous studies have demonstrated the ability of microbiota to metabolize PUFAs, although the role of the resulting metabolites in the host is less known. Recent partial evidence shows that these metabolites can have important health effects in the host, reinforcing the concept of the prebiotic action of PUFAs, despite the data being mostly related to omega-6 linoleic acid and to lactobacilli taxon. However, considering that the symbionts in our gut benefit from the nutritional molecules that we include in our diet, and that bacteria, like all living organisms, cannot benefit from a single nutritional molecule, the concept of the “correct prebiotic diet” should be the new frontier in the field of gut microbiota research.

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Effect of hypophysectomy and replacement therapy on fatty acid metabolism in the rat testis

Biochemical Journal ◽

10.1042/bj1050537 ◽

1967 ◽

Vol 105 (2) ◽

pp. 537-543 ◽

Cited By ~ 19

Author(s):

Ajit Goswami ◽

William L. Williams

Keyword(s):

Fatty Acids ◽

Linoleic Acid ◽

Polyunsaturated Fatty Acids ◽

Time Course ◽

Acid Metabolism ◽

Testicular Tissue ◽

Tracer Dose ◽

Threefold Increase ◽

Hypophysectomized Rats ◽

Time Course Study

1. The influence of pituitary gonadotrophins and of testosterone on the conversion of linoleic acid into other polyunsaturated fatty acids by rat testicular tissue was studied. 2. In immature hypophysectomized rats, follicle-stimulating hormone caused a threefold increase in the incorporation of radioactivity from [1−14C]linoleic acid into testicular lipids; the distribution of 14C in the polyunsaturated fatty acids, however, was not significantly affected. 3. In mature hypophysectomized rats, the hormonal treatments had less pronounced effects on 14C incorporation into testicular lipids, but caused a significant increase in the percentage of 14C incorporated into polyunsaturated fatty acids of the ω–6 series, luteinizing hormone and testosterone having the more pronounced influences. 4. A time-course study of the appearance of radioactivity in the ejaculated spermatozoa of rabbits, after they had been given a tracer dose of [1−14C]linoleic acid, indicated that incorporation of radioactivity into spermatozoa occurred during all stages of spermatogenesis.

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Abstract 20: Circulating Omega-6 Polyunsaturated Fatty Acids and Total and Cause-Specific Mortality: the Cardiovascular Health Study

Circulation ◽

10.1161/circ.129.suppl_1.20 ◽

2014 ◽

Vol 129 (suppl_1) ◽

Author(s):

Jason H Wu ◽

Rozenn Lemaitre ◽

Irena King ◽

Xiaoling Song ◽

David Siscovick ◽

...

Keyword(s):

Fatty Acids ◽

Linoleic Acid ◽

Polyunsaturated Fatty Acids ◽

Cardiovascular Health ◽

Cox Regression ◽

Total Mortality ◽

Health Study ◽

Cardiovascular Health Study ◽

Specific Mortality ◽

Omega 6

Background: While omega-6 polyunsaturated fatty acids (n-6 PUFA) have been recommended to reduce CHD, controversy remains about benefits vs. harms, including depending on types of n-6 PUFA and diseases examined. Aims: To assess associations of circulating n-6 PUFA including linoleic acid (LA, the major dietary PUFA), Γ-linoleic acid (GLA), dihomo-Γ-linoleic acid (DGLA), and arachidonic acid (AA),with incident total and cause-specific mortality in the Cardiovascular Health Study (CHS), a community-based US cohort. Methods: Among 2,692 participants age≥65y and free of CVD at baseline, plasma phospholipid n-6 PUFA were measured at baseline using standardized methods. All-cause and cause-specific mortality, and total (fatal or nonfatal) incident CHD and stroke, were assessed and adjudicated centrally. Associations of PUFA biomarkers with risk were assessed by multivariable Cox regression. Results: During 33,091 person-years of follow-up (1992-2010), 1920 deaths occurred (including 660 cardiovascular deaths), as well as 414 fatal and 410 nonfatal CHD events, and 150 fatal and 384 nonfatal strokes. In multivariable models, higher LA was associated with lower risk of total mortality, with extreme quintile HR 0.84 (95% CI 0.71-0.98, P- trend 0.002). Lower death was largely attributable to CVD rather than non-CVD causes, especially nonarhythmic CHD mortality (HR 0.50, 95% CI 0.31-0.80, P- trend 0.001). Phospholipid GLA, DGLA, and AA levels were not associated with total or cause-specific mortality; e.g., for AA and CHD death, the extreme quintile HR was 0.98 (95% CI 0.71-1.37, P- trend 0.72). Evaluated semi-parametrically, LA showed graded (monotonic) inverse associations with total mortality ( Figure 1A ). There was little evidence that associations of n-6 PUFA with total mortality varied by age, sex, race, or plasma n-3 PUFA (Bonferroni corrected P =NS, Figure 1B ). Conclusion: Higher circulating LA, but not other n-6 PUFA, is inversely associated with total and CHD mortality in older adults.

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