Supplementation of a γ-tocopherol-rich mixture of tocopherols in healthy men protects against vascular endothelial dysfunction induced by postprandial hyperglycemia

Mah, Eunice; Noh, Sang K.; Ballard, Kevin D.; Park, Hea Jin; Volek, Jeff S.; Bruno, Richard S.

doi:10.1016/j.jnutbio.2012.04.015

Cited by 32 publications

(27 citation statements)

References 54 publications

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“…Support for this is suggested by the subtle differences in the TG response curve; walnut oil elicited a more rapid increase than did whole walnuts. Furthermore, postprandial endothelial function is impaired after consumption of a high-fat meal (31); thus, greater bioavailability of nutrients in the oil portion (i.e., ALA and g-tocopherol) may have blunted this response and contributed to the differential effects observed between whole walnuts and walnut oil (32). Moreover, in an almond study conducted by Ellis et al (33), the bioaccessibility of almond fat was hampered by cell wall integrity such that mechanical manipulation and chewing did not enable complete release of intracellular lipids for enzymatic digestion and absorption.…”

Section: Discussionmentioning

confidence: 99%

Acute Consumption of Walnuts and Walnut Components Differentially Affect Postprandial Lipemia, Endothelial Function, Oxidative Stress, and Cholesterol Efflux in Humans with Mild Hypercholesterolemia

Berryman

Grieger

West

et al. 2013

The Journal of Nutrition

105

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Walnut consumption improves cardiovascular disease risk; however, to our knowledge, the contribution of individual walnut components has not been assessed. This study evaluated the acute consumption of whole walnuts (85 g), separated nut skins (5.6 g), de-fatted nutmeat (34 g), and nut oil (51 g) on postprandial lipemia, endothelial function, and oxidative stress. Cholesterol efflux (ex vivo) was assessed in the whole walnut treatment only. A randomized, 4-period, crossover trial was conducted in healthy overweight and obese adults (n = 15) with moderate hypercholesterolemia. There was a treatment × time point interaction for triglycerides (P < 0.01) and increased postprandial concentrations were observed for the oil and whole walnut treatments (P < 0.01). Walnut skins decreased the reactive hyperemia index (RHI) compared with baseline (P = 0.02) such that a difference persisted between the skin and oil treatments (P = 0.01). The Framingham RHI was maintained with the oil treatment compared with the skins and whole nut (P < 0.05). There was a treatment effect for the ferric reducing antioxidant potential (FRAP) (P < 0.01), and mean FRAP was greater with the oil and skin treatments compared with the nutmeat (P < 0.01). Cholesterol efflux increased by 3.3% following whole walnut consumption in J774 cells cultured with postprandial serum compared with fasting baseline (P = 0.02). Walnut oil favorably affected endothelial function and whole walnuts increased cholesterol efflux. These 2 novel mechanisms may explain in part the cardiovascular benefits of walnuts.

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Section: Discussionmentioning

confidence: 99%

Acute Consumption of Walnuts and Walnut Components Differentially Affect Postprandial Lipemia, Endothelial Function, Oxidative Stress, and Cholesterol Efflux in Humans with Mild Hypercholesterolemia

Berryman

Grieger

West

et al. 2013

The Journal of Nutrition

105

View full text Add to dashboard Cite

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“…However, not all have been evaluated in clinical trials pertaining to alleviation of oxidative stress and endothelial dysfunction. To date, most clinical trials investigating the effects of supplementation on oxidative stress and endothelial dysfunction have focused on the traditional exogenous antioxidants vitamins C and E. As with aerobic exercise training, antioxidant therapies utilizing vitamins C and E have been shown in clinical trials to reduce systemic biomarkers of oxidative stress in both healthy adults (Mah et al, 2013) and patients with preexisting vascular diseases (Abdollahzad et al, 2009). In addition, administration of vitamins C and E has been shown in some (Skyrme-Jones, O'Brien, Berry, & Meredith, 2000) but not all studies (McKechnie, Rubenfire, & Mosca, 2002;Title, Cummings, Giddens, Genest, & Nassar, 2000) to acutely improve flowmediated dilation (FMD) in patients with preexisting endothelial dysfunction.…”

Section: Antioxidant Supplementationmentioning

confidence: 99%

Reactive Oxygen and Nitrogen Species

Salisbury¹,

Bronas

2015

Nursing Research

111

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“…There are clinical implications for our studies because the g-CEHC concentrations that produced these benefits in vitro were based on blood levels reported in our previous study that demonstrated supplemental g-T protects against endothelial dysfunction induced by postprandial hyperglycemia in healthy men. 6 Phosphorylation of eNOS is involved in regulation of eNOS activity, and consequently NO production. 21 For example, increased eNOS Ser1177 phosphorylation results in greater NO production in endothelial cells.…”

Section: Discussionmentioning

confidence: 99%

“…6 Cells cultured in 5 mM glucose þ 20 mM mannitol were used as osmotic controls. In selected experiments, cells were treated for 10 min with 100 nM insulin, or saline (vehicle control) to evoke eNOS phosphorylation and NO production as previously described.…”

Section: Haecs Culture and Treatmentmentioning

confidence: 99%

γ−Carboxyethyl hydroxychroman, a metabolite of γ−tocopherol, preserves nitric oxide bioavailability in endothelial cells challenged with high glucose

Bharath

Qian

et al. 2016

Exp Biol Med (Maywood)

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Endothelial dysfunction occurs when there are imbalances between factors that regulate the synthesis and degradation of nitric oxide (NO ), and has been reported in patients with hyperglycemia and insulin resistance. We reported that supplementation with g-tocopherol (g-T) in humans limits impairments in endothelial function otherwise induced by postprandial hyperglycemia. Given the rapid metabolism of g-T into g-carboxyethyl hydroxychroman (g-CEHC), we hypothesized that the vasoprotective activities of g-T could be attributed to its metabolite g-CEHC. To test this, human aortic endothelial cells (HAECs) treated with 0 (vehicle control) or 3 mM g-CEHC for 24 h prior to incubation with normal (5 mM) or high (25 mM) glucose for 48 h. High-glucose increased levels of uncoupled endothelial nitric oxide synthase (eNOS) as evidenced by reduced (p < 0.05) eNOS dimer:monomer. High glucose also prevented insulin-stimulated increases in p-Akt Ser473 : total Akt, p-eNOS Ser1177: total eNOS, and NO production.These adverse changes were accompanied by increased (p < 0.05) reactive oxygen species and mRNA expression of inflammatory mediators (VCAM-1, E-selectin, IL-8). However, each deleterious response evoked by high glucose was prevented when HAECs were incubated with g-CEHC prior to the high glucose challenge. Taken together, our data support the hypothesis that vascular protection provided by g-T in vivo may be elicited through the bioactivity of its metabolite, g-CEHC. Furthermore, it is possible that the antioxidant and anti-inflammatory activities of g-CEHC may mediate this protective activity.

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Supplementation of a γ-tocopherol-rich mixture of tocopherols in healthy men protects against vascular endothelial dysfunction induced by postprandial hyperglycemia

Cited by 32 publications

References 54 publications

Acute Consumption of Walnuts and Walnut Components Differentially Affect Postprandial Lipemia, Endothelial Function, Oxidative Stress, and Cholesterol Efflux in Humans with Mild Hypercholesterolemia

Acute Consumption of Walnuts and Walnut Components Differentially Affect Postprandial Lipemia, Endothelial Function, Oxidative Stress, and Cholesterol Efflux in Humans with Mild Hypercholesterolemia

Reactive Oxygen and Nitrogen Species

γ−Carboxyethyl hydroxychroman, a metabolite of γ−tocopherol, preserves nitric oxide bioavailability in endothelial cells challenged with high glucose

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