Gamma-tocotrienol attenuates the aberrant lipid mediator production in NLRP3 inflammasome-stimulated macrophages

Kim Y, Gromovsky AD, Brown JM, Chung S

J Nutr Biochem. 2018 Jun 4;58:169-177. doi: 10.1016/j.jnutbio.2018.05.007. [Epub ahead of print]

Abstract

The activation of NLRP3 inflammasome in innate immune cells is associated with enhanced production of pro-inflammatory lipid mediator eicosanoids that play a crucial role in propagating inflammation. Gamma-tocotrienol (γT3) is an unsaturated vitamin E that has been demonstrated to attenuate NLRP3-inflammasome. However, the role of γT3 in regulating eicosanoid formation is unknown. We hypothesized that γT3 abolishes the eicosanoid production by modulating the macrophage lipidome. LPS-primed bone marrow-derived macrophages (BMDM) were stimulated with saturated fatty acids (SFA) along with γT3, and the effects of γT3 in modulating macrophage lipidome were quantified by using mass spectrometry based-shotgun lipidomic approaches. The SFA-mediated inflammasome activation induced robust changes in lipid species of glycerolipids (GL), glycerophospholipids (GPL), and sphingolipids in BMDM, which were distinctly different in the γT3-treated BMDM. The γT3 treatment caused substantial decreases of lysophospholipids (LysoPL), diacylglycerol (DAG), and free arachidonic acid (AA, C20:4), indicating that γT3 limits the availability of AA, the precursor for eicosanoids. This was confirmed by the pulse-chase experiment using [³H]-AA, and by diminished prostaglandin E₂ (PGE₂) secretion by ELISA. Concurrently, γT3 inhibited LPS-induced cyclooxygenases 2 (COX2) induction, further suppressing prostaglandin synthesis. In addition, γT3 attenuated ceramide synthesis by transcriptional downregulation of key enzymes for de novo synthesis. The altered lipid metabolism during inflammation is linked to reduced ATP production, which was partly rescued by γT3. Taken together, our work revealed that γT3 induces distinct modification of the macrophage lipidome to reduce AA release and corresponding lipid mediator synthesis, leading to attenuated cellular lipotoxicity.

Nor Azman NHE, Goon JA, Abdul Ghani SM, Hamid Z, Wan Ngah WZ

Antioxidants (Basel). 2018 May 28;7(6). pii: E74. doi: 10.3390/antiox7060074.

Abstract

BACKGROUND:

Tocotrienol and tocopherol are known to prevent numerous degenerative diseases. The aim of this study is to compare the effects of tocotrienol-rich fraction (TRF) with α-tocopherol (α-TF) on the antioxidant status of healthy individuals aged between 50 and 55 years.

METHODS:

Volunteers were divided into groups receiving placebo (n = 23), α-TF (n = 24) and TRF (n = 24). Fasting venous blood samples were taken at baseline (0 month), 3 months and 6 months of supplementation for the determination of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities as well as for reduced glutathione (GSH) and oxidized glutathione (GSSG) concentrations.

RESULTS:

CAT and GPx were unaffected by TRF and α-TF supplementations. SOD activity increased significantly after six months of TRF supplementation. Analysis by gender showed that only female subjects had significant increases in SOD and GPx activities after six months of TRF supplementation. GPx activity was also significantly higher in females compared to males after six months of TRF supplementation. The GSH/GSSG ratio increased significantly after six months of TRF and α-TF supplementation in only the female subjects.

CONCLUSION:

TRF and α-TF supplementation exhibited similar effects to the antioxidant levels of older adults with TRF having more significant effects in females.

Rajagopalan P, Jain AP, Nanjappa V, Patel K, Mangalaparthi KK, Babu N, Cavusoglu N, Roy N, Soeur J, Breton L, Pandey A, Gowda H, Chatterjee A, Misra N

J Dermatol Sci. 2018 May 21. pii: S0923-1811(18)30215-9. doi: 10.1016/j.jdermsci.2018.05.003. [Epub ahead of print]

Abstract

BACKGROUND:

Skin acts as a protective barrier against direct contact with pollutants but inhalation and systemic exposure have indirect effect on keratinocytes. Exposure to diesel exhaust has been linked to increased oxidative stress.

OBJECTIVE:

To investigate global proteomic alterations in diesel particulate extract (DPE)/its vapor exposed skin keratinocytes.

METHODS:

We employed Tandem Mass Tag (TMT)-based proteomics to study effect of DPE/DPE vapor on primary skin keratinocytes.

RESULTS:

We observed an increased expression of oxidative stress response protein NRF2, upon chronic exposure of primary keratinocytes to DPE/its vapor which includes volatile components such as polycyclic aromatic hydrocarbons (PAHs). Mass spectrometry-based quantitative proteomics led to identification 4490 proteins of which 201 and 374 proteins were significantly dysregulated (≥1.5 fold, p ≤ 0.05) in each condition, respectively. Proteins involved in cellular processes such as cornification (cornifin A), wound healing (antileukoproteinase) and differentiation (suprabasin) were significantly downregulated in primary keratinocytes exposed to DPE/DPE vapor. These results were corroborated in 3D skin models chronically exposed to DPE/DPE vapor. Bioinformatics analyses indicate that DPE and its vapor affect distinct molecular processes in skin keratinocytes. Components of mitochondrial oxidative phosphorylation machinery were seen to be exclusively overexpressed upon chronic DPE vapor exposure. In addition, treatment with an antioxidant like vitamin E partially restores expression of proteins altered upon exposure to DPE/DPE vapor.

CONCLUSIONS:

Our study highlights distinct adverse effects of chronic exposure to DPE/DPE vapor on skin keratinocytes and the potential role of vitamin E in alleviating adverse effects of environmental pollution.

Aghadavod E, Soleimani A, Hamidi G, Keneshlou F, Heidari A, Asemi Z

Iran J Kidney Dis. 2018 May;12(3):156-162.

Abstract

INTRODUCTION:

Patients with diabetic nephropathy (DN) may benefit from vitamin E‘s antilipid and antioxidant activities. This study aimed to evaluate the effects of high-dose vitamin E supplementation on markers of cardiometabolic risk and oxidative stress in patients with DN.

MATERIALS AND METHODS:

This randomized controlled trial was carried out on 54 patients with DN that were randomly divided into 2 groups to receive vitamin E supplement (800 IU/d) or placebo for 12 weeks. Fasting blood samples were obtained at baseline and after the 12-week intervention to determine markers of cardiometabolic risk and oxidative stress.

RESULTS:

Vitamin E supplementation, compared with the placebo, resulted in a significant reduction in serum total cholesterol (-14.3 ± 29.9 mg/dL versus -0.8 ± 13.1 mg/L, P = .03), low-density lipoprotein cholesterol (-16.4 ± 28.5 mg/dL versus 0.1 ± 17.2 mg/L, P = .01), and ratio of total cholesterol to high-density lipoprotein cholesterol ratio (-0.5 ± 0.7 versus 0.1 ± 0.5, P = .001), and a significant elevation in vitamin Elevels (39.7 ± 12.4 nmol/mL versus -0.5 ± 1.3 nmol/mL, P < .001) and high-density lipoprotein cholesterol levels (1.4 ± 3.7 versus -2.1 ± 5.1 mg/L, P = .006). It also resulted in a significant elevation in plasma glutathione levels.

CONCLUSIONS:

Our study demonstrated that high-dose vitamin E supplementation for 12 weeks had favorable effects on lipid profile and glutathione levels of patients with DN, except for triglycerides, very low-density lipoprotein cholesterol, nitric oxide, and total antioxidant capacity levels.

Sarac M, Bakal U, Kuloglu T, Tartar T, Aydin S, Yardim M, Artas G, Kazez A

Ann Clin Lab Sci. 2018 May;48(3):345-354.

Abstract

INTRODUCTION:

Delay in the diagnosis of ovarian torsion leads to serious histopathological changes and many problems, including infertility. Various agents have been investigated to minimize detorsion-associated potential injury. This study was performed to study the effects of carnosine and vitamin E on tissue and serum expression of Nucleobindin 2 (NUCB2)/nesfatin-1, ghrelin, adropin, and irisin to determine whether they have protective effects in cases of ovarian torsion.

MATERIAL AND METHOD:

Seventy-eight rats were allocated evenly into 13 groups. All rats, excluding those in the control and sham groups and Groups (G) III, IV, and V, were subjected to ovarian torsion for 12 hours. The groups were designated as follows: G-I (control), G-II (sham), G-III (vitamin E), G-IV (carnosine), G-V (carnosine + vitamin E), G-VI (torsion), G-VII (torsion + detorsion), G-VIII (torsion + vitamin E), G-IX (torsion + carnosine), G-X (torsion + carnosine + vitamin E), G-XI (torsion + detorsion + vitamin E), G-XII (torsion + detorsion + carnosine), and G-XIII (torsion + detorsion + carnosine + vitamin E). Serum levels of NUCB2/nesfatin-1, ghrelin, adropin, and irisin were measured by ELISA. Immunohistochemical methods were used to measure the expression of these hormones in ovarian tissue.

RESULTS:

The levels of NUCB2/nesfatin-1 immunoreactivity were increased in G-VII, G-XI, and G-XII (p<0.05). The immunoreactivity of ghrelin was significantly decreased in G-VI, G-IX, G-XI, and G-XII. However, adropin immunoreactivity did not differ significantly between the groups (p>0.05). The level of irisin immunoreactivity was decreased in G-VI, G-VII, and G-VIII (p<0.05). The serum levels of NUCB2/nesfatin-1, ghrelin, adropin, and irisin paralleled the tissue immunohistochemical results.

CONCLUSION:

Carnosine and vitamin E protected the ovaries from ischemia-reperfusion injury in ovarian torsion. These antioxidants, especially carnosine, may be useful for the treatment of ovarian torsion.

Pervez MA, Khan DA, Ijaz A, Khan S.

Turk J Gastroenterol. 2018 Mar;29(2):170-176. doi: 10.5152/tjg.2018.17297.

Abstract

BACKGROUND/AIMS:

Non-alcoholic fatty liver disease (NAFLD) is a growing public health problem worldwide and is associated with increased morbidity and mortality. Currently, there is no definitive treatment for this disease. δ-Tocotrienol has potent anti-inflammatory and antioxidant properties and may reduce liver injury in NAFLD. The present study aims to evaluate the efficacy and safety of δ-tocotrienol in the treatment of NAFLD.

MATERIALS AND METHODS:

The present study was a randomized, double-blind, placebo-controlled pilot study conducted in patients aged > 20 years, belonging to both sexes, having ultrasound-proven fatty liver disease, having a fatty liver index (FLI) of ≥ 60, and persistent elevation of alanine transaminase. A total of 71 patients were assigned to receive either oral δ-tocotrienol (n=35, 300 mg twice daily) or placebo (n=36) for 12 weeks. At the baseline and at the end of the study, clinical and biochemical parameters, including lipid profile, liver function tests, high-sensitivity C-reactive protein (hs-CRP), and malondialdehyde (MDA) were measured. Body mass index and FLI were calculated, and ultrasound grading of hepatic steatosis was performed.

RESULTS:

Out of 71 enrolled patients, 64 patients, 31 in the δ-tocotrienol group and 33 in the placebo group, completed the study. After 12 weeks of supplementation, δ-tocotrienol showed greater efficacy than placebo by decreasing serum aminotransferases, hs-CRP, MDA, and FLI score (p<0.001). However, it did not improve hepatic steatosis on ultrasound examination. No adverse effects were reported.

CONCLUSION:

δ-Tocotrienol was safe, and it effectively improved aminotransferase levels and inflammatory and oxidative stress markers in patients with NAFLD. Large-scale randomized clinical trials are warranted to further support these findings.

Kumar MR, Reddy GR

Hum Exp Toxicol. 2018 Mar;37(3):295-308. doi: 10.1177/0960327117698540. Epub 2017 Mar 23.

Abstract

This study was planned to determine arsenic (As) (10 mg/kg body weight given through oral gavage) induced behavioral and cholinergic perturbations in three different age groups of rats; young (postnatal day 21), adult (3 months), and aged (18 months) at 7 days post-acute exposure ( n = 6 for each of the four groups of all three age points). Further, we also evaluated the ameliorative effect of essential metal zinc (Zn; 0.02% through drinking water) and an antioxidant, α-tocopherol (vitamin E; 125 mg/kg body weight through oral gavage) against As-induced neurotoxicity. As exposure showed significant alterations in behavioral functions (open-field behavior, total locomotor activity, grip strength, exploratory behavior, and water maze learning). Cholinergic studies in three brain regions (cerebral cortex, cerebellum, and hippocampus) of different age groups also showed significant increase in acetylcholine levels and a decrease in acetylcholinesterase activity. These effects were more pronounced in hippocampus followed by cerebral cortex and cerebellum. Among the three different age points, aged animals were found to be more vulnerable to the As-induced toxicity as compared to young and adult animals suggesting that As neurotoxicity is age dependent. These As-induced alterations were significantly reversed following supplementation with Zn or vitamin E. However, vitamin E was found to elicit greater protection as compared to Zn in restoring the altered behavioral and cholinergic perturbations, providing evidence for As-induced oxidative damage.

Pourafshar S, Johnson SA, Keshavarz B, Feresin RG, Khalil DA, Chai SC, Arjmandi BH

Menopause. 2018 Mar;25(3):336-342. doi: 10.1097/GME.0000000000001003.

Abstract

OBJECTIVE:

Menopause is associated with adverse changes in hematological parameters. Although the antioxidative and anti-inflammatory properties of vitamin E have been previously demonstrated, the effects of vitamin E on hematopoietic parameters are not well-documented. This study investigated the effects of supplemental vitamin E on hematological parameters in a rat model of ovarian hormone deficiency.

METHODS:

Twelve-month-old female Sprague-Dawley rats were either sham-operated (Sham) or ovariectomized (Ovx). Animals were randomly divided among five treatment groups (n = 12/group) as follows: Sham; Ovx; Ovx + 300, Ovx + 525, or Ovx + 750 mg/kg diet of vitamin E for 100 days.

RESULTS:

Compared with Sham, ovariectomy increased leukocyte subpopulation counts including lymphocytes (2.01 × 10/mm; 95% confidence interval [CI] 0.11, 4.03; P = 0.03), monocytes (0.35 × 10/mm; 95% CI 0.60, 0.11; P = 0.01), neutrophils (0.72 × 10/mm; 95% CI 0.26, 1.19; P = 0.01), eosinophils (0.07 × 10/mm; 95% CI 0.12, 0.30; P = 0.00), and basophils (0.13 × 10/mm; 95% CI 0.04, 0.21; P = 0.02). Medium dose (MD) (-0.26 × 10/mm; 95% CI -0.47, -0.05; P = 0.007) and high dose (HD) (-0.22 × 10/mm; 95% CI -0.43, -0.01; P = 0.037) supplemental vitamin E attenuated Ovx-induced increases in monocyte counts. Low dose (LD) (-0.55 × 10/mm; 95% CI -0.95, -0.15; P = 0.003), MD (-0.61 × 10/mm; P = 0.001), and HD (-0.54 × 10/mm; 95% CI -0.95, -0.14; P = 0.004) supplemental vitamin E attenuated Ovx-induced increases in neutrophil counts. LD (-0.05 × 10/mm; 95% CI -0.08, -0.11; P = 0.006), MD (-0.05 × 10/mm; 95% CI -0.08, -0.11; P = 0.005), and HD (-0.05 × 10/mm; 95% CI -0.09, -0.01; P = 0.004) supplemental vitamin E also attenuated the Ovx-induced increase in eosinophil counts. Only LD (-0.09 × 10/mm; 95% CI -0.17, -0.02; P = 0.009) supplemental vitamin E attenuated the Ovx-induced increase in basophil counts. The remaining hematological parameters assessed were not significantly affected by ovariectomy or supplemental vitamin E.

CONCLUSION:

These findings suggest that vitamin E in the form of α-tocopherol acetate may provide protection against ovarian hormone deficiency-associated adverse changes in hematological parameters.

Zang S, Chen J, Song Y, Bai L, Chen J, Chi X, He F, Sheng H, Wang J, Xie S, Xie W, Yang Y, Zhang J, Zheng M, Zou Z, Wang B, Shi J

Adv Ther. 2018 Feb;35(2):218-231. doi: 10.1007/s12325-018-0670-8. Epub 2018 Feb 6.

Abstract

INTRODUCTION:

Vitamin E is one of the most promising agents for nonalcoholic steatohepatitis (NASH) treatment, and its drug responsiveness may be closely associated with haptoglobin (Hp) genotype. However, its efficacy and safety remain unknown in China. This clinical trial of vitamin E versus placebo for the treatment of nondiabetic patients with nonalcoholic steatohepatitis (VENS) is conducted to evaluate (a) the efficacy and safety of treatment with vitamin E softgel (300 mg/day) determined from standardized histologic scoring of liver biopsies, (b) whether treatment with vitamin E improves biochemical parameters, cytokines, anthropometric parameters, controlled attenuation parameter (CAP), and transient elastography (TE) values determined by Fibroscan and health-related quality of life (SF-36), (c) whether the efficacy of vitamin E treatment is associated with the Hp genotype in nondiabetic adults with NASH.

METHODS:

VENS is a multicenter, randomized, double-masked, placebo parallel controlled trial to evaluate the efficacy and safety of treatment with vitamin E softgel in nondiabetic adults with NASH versus treatment with placebo in China. Liver biopsies are read by a pathological evaluation committee independently according to the NASH Clinical Research Network (CRN) scoring system. The NAFLD activity score (NAS) represents the sum of scores for steatosis, lobular inflammation, and hepatocyte ballooning. The definition of histologic improvement requires all three of the following criteria to be met: (a) either improvement in NAS by at least 2 points or post-treatment NAS score no higher than 3, (b) at least 1-point improvement in the score for ballooning, and (c) no worsening of fibrosis stages. We plan to recruit 120 biopsy-proven NASH patients from13 centers in China. Participants will be randomly assigned to groups treated with either with vitamin E (100 mg, tid) or placebo for 96 weeks then followed by 24 weeks of post-treatment observation. Biochemical parameters, cytokines, anthropometric parameters, CAP and TE values, Hp genotype, and several questionnaires will be collected as per the schedule. This protocol was approved by the Ethics Committee of Hangzhou Normal University Affiliated Hospital to ensure patients safety, and R&G Pharmastudies Co., Ltd. was established for monitoring the accumulated interim data to review efficacy and quality of data collection and overall study management.

RESULTS:

As a preliminary study, a mobile phone application (app) for lifestyle modification and database recording ( http://laiyivens.365hy.com ) was exploited for every participant. The percentage of NAFLD patients with Hp 2-2 allele is much higher than that of Western patients (65.71% vs 36%, respectively), which suggests that the Chinese benefit more from vitamin E treatment.

CONCLUSION:

VENS is the first randomized controlled trial (RCT) to evaluate the efficacy of Vitamin E in treating nondiabetic NASH patients in China.

Ghlissi Z, Hakim A, Mnif H, Kallel R, Zeghal K, Boudawara T, Sahnoun Z

Saudi J Kidney Dis Transpl. 2018 Jan-Feb;29(1):10-18. doi: 10.4103/1319-2442.225205.

Abstract

This study was carried out to evaluate spontaneous renal regeneration after stopping colistin methanesulfonate (CMS), which induces tubular damage, and the curative effect of Vitamin E (vit E) in rats. Animals were given the following: sterile saline (n = 6), 300,000 IU/kg/ day of CMS (n = 24), or 450,000 IU/kg/day of CMS (n = 24) for seven days. Each CMS group was subdivided into four subgroups (n = 6) and sacrificed as follows: (i) 12 h after stopping CMS, (ii) two weeks after stopping CMS, (iii) two weeks after stopping treatment with vit E, and (iv) two weeks after stopping treatment with olive oil. Subsequently, plasma creatinine (pCr), urine N-acetyl-b-D-glucosaminidase (NAG), renal tissue level of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione reductase (GSH), and renal histology were tested. CMS-induced tubular damage increased the NAG and MDA levels and decreased the SOD and GSH activities. After two weeks of stopping CMS, there was no significant renal recovery. However, treatment with vit E improved tubular regeneration and reduced the biochemical impairments. Two weeks might not be long enough for significant spontaneous renal regeneration. Improvement of renal parameters by vit E could be explained by the reduction of oxidative stress damage.