The effect of omega-3 and vitamin E on oxidative stress and inflammation: Systematic review and meta-analysis of randomized controlled trials

Moosavian SP, Arab A, Mehrabani S, Moradi S, Nasirian M

Int J Vitam Nutr Res. 2019 Aug 23:1-11. doi: 10.1024/0300-9831/a000599. [Epub ahead of print]

Abstract

Background: Several studies have investigated the effect of omega-3 fatty acids and vitamin E on oxidative stress and inflammation, but their findings are inconsistent. The aim of this meta-analysis is to elucidate the overall effects of co-supplementation with omega-3 fatty acids and vitamin E on oxidative stress and inflammation. Methods: We searched titles, abstracts, and keywords of relevant articles indexed in PubMed, ISI, Scopus, and Google Scholar databases up to December 2018 to identify eligible RCT studies. Random effects model was used to estimate the pooled effect of co-supplementation with omega-3 fatty acids and vitamin E on oxidative stress and inflammation. Results:Overall, 7 RCTs with 504 participants were included in this meta-analysis. We found that co-supplementation with omega-3 fatty acids and vitamin E decreased hs-CRP (weighed mean difference (WMD) = -2.15 mg/L; 95% CI: -3.40, -0.91 mg/L; P < 0.001) concentrations and increased total antioxidant capacity (TAC) (WMD = 92.87 mmol/L; 95% CI: 31.97, 153.77 mmol/L; P = 0.03), and nitric oxide levels (NO) (WMD: 6.95 μmol/L; 95% CI: 3.86, 10.04, P < 0.001) compared with control group. Omega-3 fatty acids and vitamin E had no significant effect on malondialdehyde (MDA) (WMD: 1.54 mmol/L; 95% CI: -1.29, 4.36; P = 0.196), and glutathione (GSH) (WMD: 20.87 mmol/L; 95% CI: -20.04, 61.6, P = 0.31) levels. Conclusion: The present meta-analysis found that omega-3 fatty acids and vitamin E co-supplementation significantly decreased hs-CRP and increased NO and TAC, although it had no significant effect on MDA and GSH.

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The Potential Physiological Role of γ-Tocopherol in Human Health: A Qualitative Review

Thompson MD, Cooney RV

Nutr Cancer. 2019 Aug 22:1-18. doi: 10.1080/01635581.2019.1653472. [Epub ahead of print]

Abstract

Chronic aging-related diseases result in the greatest burden to the health care system, yet there is little agreement on optimal levels of vitamins or the functional significance of many other dietary molecules in disease prevention. This review presents accumulated information regarding the role of γ-tocopherol in the prevention of nitrogen oxide-mediated damage and its impact on aging-related diseases. γ-Tocopherol is ubiquitous in the diet and levels appear to be physiologically regulated such that levels rise in response to inflammation and deficiencies in certain key vitamins. The unique antioxidant properties of γ-tocopherol, whereby DNA-damaging nitrogen dioxide is rapidly converted to nitric oxide, suggest a mechanistic justification for a functional role in the prevention of DNA damage over time. Data from cell, animal, and human studies indicate that γ-tocopherol appears to have significant beneficial effects, protecting cells from inflammatory damage; however, interpretation of epidemiologic studies is complex due to the paradoxical rise in levels of γ-tocopherol in response to known etiologic risk factors. Current knowledge of its antioxidant mechanism of action, apparent physiological regulation, and impact on various enzymatic pathways suggests γ-tocopherol may have a functional role in maintaining human health. Its utility as a biomarker and the consequences of its deficiency deserve further study.

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Effect of vitamin E in non-alcoholic fatty liver disease: a systematic review and meta-analysis of randomised controlled trials

Amanullah I, Khan YH, Anwar I, Gulzar A, Mallhi TH, Raja AA

Postgrad Med J. 2019 Aug 21. pii: postgradmedj-2018-136364. doi: 10.1136/postgradmedj-2018-136364. [Epub ahead of print]

Abstract

The efficacy of vitamin E among patients with non-alcoholic fatty liver disease (NAFLD) is unclear. The current qualitative and quantitative analyses aimed to ascertain the efficacy of vitamin E on clinical outcomes of patients with NAFLD. A systematic search of randomised controlled trials (RCTs) was performed using databases (PubMed, ProQuest, Scopus, EBSCOhost and Ovid) from inception to July 2018. Trials meeting the inclusion criteria were subjected to quality assessment using the Jadad Scoring. All trials meeting the prerequisites information for meta-analysis were subjected to quantitative synthesis of results. Nine RCTs (five in adults and four in children) were included. Four of the five RCTs on adults demonstrated significant improvements in alanine transaminase and other liver function surrogates in patients with NAFLD. On the other hand, only one of the four RCTs conducted on children showed significant improvements in liver functions with the use of vitamin E. Although quantitative synthesis of available data revealed insignificant differences between vitamin E and placebo, still the use of vitamin E improves the level of alanine transaminase and aspartate transaminase by -1.96 and -0.59, with heterogeneity of I2=67% and I2=0%, respectively. Adjuvant vitamin E therapy provides significant biochemical and histological improvements in adult patients with NAFLD, while paediatric patients showed insignificant efficacy compared with placebo. Lifestyle interventions along with vitamin E can provide much better results. Data, including the impact of vitamin E on hepatic histology, are still lacking. Moreover, the short duration of trials limits the conclusion on the safety and efficacy of proposed treatments.

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Maternal omega-3 fatty acids and vitamin E improve placental angiogenesis in late-onset but not early-onset preeclampsia

Kasture V, Sundrani D, Dalvi S, Swamy M, Kale A, Joshi S

Mol Cell Biochem. 2019 Aug 16. doi: 10.1007/s11010-019-03599-4. [Epub ahead of print]

Abstract

Abnormal placental vasculature is associated with preeclampsia. Preeclampsia is of two types, i.e., early- and late-onset preeclampsia (LOP), both having different etiologies. We have earlier demonstrated low levels of omega-3 fatty acids and vitamin E in women with preeclampsia. The current study examines the effect of maternal omega-3 fatty acids and vitamin E supplementation on angiogenic factors in a rat model of preeclampsia. Pregnant rats were divided into a total of five groups control, early-onset preeclampsia (EOP); LOP; EOP supplemented with omega-3 fatty acid and vitamin E and LOP supplemented with omega-3 fatty acid and vitamin E. Preeclampsia was induced by administering L-nitroarginine methylester (L-NAME) at the dose of 50 mg/kg body weight/day. The vascular endothelial growth factor gene expression and protein levels were lower (p < 0.01 for both) in animals from both EOP as well as LOP groups (p < 0.01). In the EOP group, the protein levels of VEGF receptor-1 were also lower (p < 0.01). Supplementation of omega-3 fatty acids and vitamin E to LOP improved the levels of VEGF and VEGF receptor-1 only in the LOP but not in the EOP group. In the EOP group, the gene expression of hypoxia inducible factor 1 alpha (HIF-1α) in the placenta was higher (p < 0.05) and supplementation normalized these levels. Our findings indicate that maternal supplementation of omega-3 fatty acids and vitamin E has differential effect on preeclampsia subtypes.

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Synthesis of Daidzein Glycosides, α-Tocopherol Glycosides, Hesperetin Glycosides by Bioconversion and Their Potential for Anti-Allergic Functional-Foods and Cosmetics

Fujitaka Y, Hamada H, Uesugi D, Kuboki A, Shimoda K, Iwaki T, Kiriake Y, Saikawa T

Molecules. 2019 Aug 16;24(16). pii: E2975. doi: 10.3390/molecules24162975.

Abstract

Daidzein is a common isoflavone, having multiple biological effects such as anti-inflammation, anti-allergy, and anti-aging. α-Tocopherol is the tocopherol isoform with the highest vitamin E activity including anti-allergic activity and anti-cancer activity. Hesperetin is a flavone, which shows potent anti-inflammatory effects. These compounds have shortcomings, i.e., water-insolubility and poor absorption after oral administration. The glycosylation of bioactive compounds can enhance their water-solubility, physicochemical stability, intestinal absorption, and biological half-life, and improve their bio- and pharmacological properties. They were transformed by cultured Nicotiana tabacum cells to 7-β-glucoside and 7-β-gentiobioside of daidzein, and 3′- and 7-β-glucosides, 3′,7-β-diglucoside, and 7-β-gentiobioside of hesperetin. Daidzein and α-tocopherol were glycosylated by galactosylation with β-glucosidase to give 4′- and 7-β-galactosides of daidzein, which were new compounds, and α-tocopherol 6-β-galactoside. These nine glycosides showed higher anti-allergic activity, i.e., inhibitory activity toward histamine release from rat peritoneal mast cells, than their respective aglycones. In addition, these glycosides showed higher tyrosinase inhibitory activity than the corresponding aglycones. Glycosylation of daidzein, α-tocopherol, and hesperetin greatly improved their biological activities.

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Comparing the effects of Portulaca oleracea seed hydro-alcoholic extract, valsartan, and vitamin E on hemodynamic changes, oxidative stress parameters and cardiac hypertrophy in thyrotoxic rats

Pakdel R, Vatanchian M, Niazmand S, Beheshti F, Rahimi M, Aghaee A, Hadjzadeh MA

Drug Chem Toxicol. 2019 Aug 15:1-8. doi: 10.1080/01480545.2019.1651330. [Epub ahead of print]

Abstract

The present study compared the effects of Portulaca oleracea (P. oleracea) seed hydro-alcoholic extract, valsartan, and vitamin E on hemodynamic changes, oxidative stress markers and cardiac hypertrophy in a model of thyrotoxicosis. The hyperthyroid state was induced by intraperitoneal injection of levothyroxine (100 µg/kg) for 4 weeks in male adult rats. After 2 weeks, vitamin E (20 mg/kg), valsartan (8 mg/kg), and P. oleracea seed extract (400 mg/kg) were administered in three groups of thyrotoxic rats. The control group was given a daily injection of normal saline. Systolic blood pressure and heart rate were measured on three occasions with tail cuff. At the end of the fourth week, the animals were scarified and serum samples and heart tissue were collected for biochemical and histological studies. The levothyroxine increased heart rate and systolic blood pressure. A lower heart rate and reduced systolic blood pressure were observed in groups receiving valsartan and P. oleracea extract. The heart weight/body weight ratio increased in groups treated with levothyroxine, but in a microscopic study, cardiomyocyte width was not different between the groups. Levothyroxine increased the level of malondyaldehide and NO metabolite but reduced the thiol concentration, superoxide dismutase, and catalase activities. However, treatment with vitamin E and P. oleracea extract increased the thiol concentration, superoxide dismutase and catalase activities while decreasing malondyaldehide level. In addition, treatment with P. oleracea extract and valsartan decreased NO metabolite level. Treatment with P. oleracea extract improved levothyroxine induced oxidative stress and hemodynamic changes. These effects may be for antioxidant components.

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Alpha-Tocopherol during lactation and after weaning alters the programming effect of prenatal high salt intake on cardiac and renal functions of adult male offspring

Cabral EV, Vieira LD, Sant'Helena BRM, Ribeiro VS, Farias JS, Aires RS, Paz ST, Muzi-Filho H, Paixão AD, Vieyra A

Clin Exp Pharmacol Physiol. 2019 Aug 14. doi: 10.1111/1440-1681.13161. [Epub ahead of print]

Abstract

Maternal salt overload programs cardiovascular and renal alterations in the offspring. However, beneficial and harmful effects of high dose vitamin E supplementation have been described in humans and animals. We investigated the hypothesis as to whether cardiac and renal alterations can be programmed by gestational salt overload, and can become further modified during lactation and after weaning. Male Wistar rats were used, being the offspring of mothers that drank either tap water or 0.3 M NaCl for 20 days before and during pregnancy. α-Tocopherol (0.35 g/kg) was administered to mothers daily during lactation or to their offspring for 3 weeks post-weaning. Systolic blood pressure (tcSBP) was measured in juvenile rats aged 210 days. The response of mean arterial pressure (MAP) and heart rate (HR) to intravenous infusion of angiotensin II (Ang II) was also examined. Left ventricle plasma membrane (PMCA) and sarcoplasmic reticulum Ca2+-ATPase (SERCA) activities, and certain parameters of renal function, were measured. Maternal saline programmed for increased body mass and kidney mass/body mass ratio, increased tcSBP, increased mean arterial pressure and heart rate with anomalous response to infused Ang II. In the heart, saline increased PMCA and α-Tocopherol per se increased PMCA/SERCA. In the kidney, the most remarkable result was the silent saline programming of CrCl , which was sensitized for a sharp decrease after α-Tocopherol. In conclusion, the combination of maternal saline overload and high α-Tocopherol immediately after birth leads to simultaneous cardiovascular and renal alterations in the young offspring, like those encountered in type V cardiorenal syndrome.

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