Effect of alpha-tocopherol and dose sensitivity on pancreatitis formation in rats with experimental pancreatitis

Deniz Tazeoğlu, Cüneyt Akyüz, Mehmet Gökçeimam, Gülçin Harman Kamalı, Ayhan Özsoy, Servet Rüştü Karahan

Ulus Travma Acil Cerrahi Derg . 2021 Nov;27(6):605-612. doi: 10.14744/tjtes.2020.89054.

Abstract

Background: Acute pancreatitis is an inflammatory disease accompanied by pancreatic inflammation characterized by acinar cell damage and leukocyte infiltration in the tissue. At present, mortality and morbidity rates are high despite the current treatment of pancreatitis; therefore, new studies and treatment studies are needed. In this study, the effects of alpha-tocopherol on different doses of L-arginine-induced experimental acute pancreatitis model were investigated.

Methods: Thirty adult male Sprague-Dawley albino rats were randomly divided into four groups; control (sham) group (n=6), acute pancreatitis group (n=8), low-dose alpha-tocopherol (200 mg/kg once intraperitoneal [IP]) group (n=8), and high dose alpha-tocopherol (400 mg/kg once ip) group (n=8). Experimental acute pancreatitis model was created by a single IP dose of 5 g/kg of L-arginine. Alpha-tocopherol was administered in a single dose intraperitoneally, 30 min before the creation of the experimental model of acute pancreatitis induced by L-arginine induction in Groups 3 and 4. Tissue and blood samples were taken under anesthesia 72 h after L-arginine injection; then the rats were sacrificed by decapitation. Serum amylase, lipase, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-alpha, and C-reactive protein (CRP) levels were examined. Pancreatic tissue samples were examined under a light microscope for histopathological examination.

Results: When the acute pancreatitis group (Group 2) was compared to the control group (Group 1), serum amylase, lipase, IL-1β, IL-6, TNF-alpha, and CRP levels were all significantly increased (p<0.05 for all). Histopathological examination showed significant difference in edema (p<0.001) and inflammation (p=0.007) scores. When the low (Group 3) and high (Group 4) dose alpha-tocopherol groups were compared to Group 2, amylase, lipase, IL-1β, IL-6, TNF-alpha, and CRP parameters were statistically significantly lower (p<0.05 for all). In the histopathological comparison of Groups 2, 3, and 4, edema and inflammation scores were decreased in Groups 3 and 4 compared to Group 2. Comparing Group 4 to Group 3, lipase (p<0.01), IL-6 (p=0.038), and TNF-alpha (p=0.002) levels were significantly decreased; no significant difference was observed in the histopathological evaluation.

Conclusion: Alpha-tocopherol was found to reduce inflammation and pancreatic damage in acute pancreatitis and was more effective in high doses.

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Different forms of vitamin E and metabolite 13′-carboxychromanols inhibit cyclooxygenase-1-catalyzed thromboxane in platelets, and tocotrienols and 13′-carboxychromanols are competitive inhibitors of 5-lipoxygenase

Na-Young Park, Suji Im, Qing Jiang

J Nutr Biochem . 2021 Oct 25;108884. doi: 10.1016/j.jnutbio.2021.108884. Online ahead of print.

Abstract

Cyclooxygenase (COX-1 and COX-2)- and 5-lipoxygenase (5-LOX)-catalyzed biosynthesis of eicosanoids play important roles in inflammation and chronic diseases. The vitamin E family has four tocopherols and tocotrienols. We have shown that the metabolites of δ-tocopherol (δT) and δ-tocotrienol (δTE), i.e., δT-13′-carboxychromanol (COOH) and δTE-13′-COOH, respectively, inhibit COX-1/-2 and 5-LOX activity, but the nature of how they inhibit 5-LOX is not clear. Further, the impact of tocopherols and tocotrienols on COX-1/-2 or 5-LOX activity has not been fully delineated. In this study, we found that tocopherols and tocotrienols inhibited human recombinant COX-1 with IC50s of 1-12 µM, and suppressed COX-1-mediated formation of thromboxane in collagen-stimulated rat’s platelets with IC50s of 8-50 µM. None of the vitamin E forms directly inhibited COX-2 activity. 13′-COOHs inhibited COX-1 and COX-2 enzyme activity with IC50s of 3-4 and 4-10 µM, respectively, blocked thromboxane formation in collagen- and ionophore-stimulated rats’ platelets with IC50s of 1.5-2.5 µM, and also inhibited COX-2-mediated prostaglandins in stimulated cells. Using enzyme kinetics, we observed that δT-13′-COOH, δTE-13′-COOH and δTE competitively inhibited 5-LOX activity with Ki of 1.6, 0.8 and 2.2 µM, respectively. These compounds decreased leukotriene B4 from stimulated neutrophil-like cells without affecting translocation of 5-LOX from cytosol to the nucleus. Our study reveals inhibitory effects of vitamin E forms and 13′-COOHs on COX-1 activity and thromboxane formation in platelets, and elucidates mechanisms underlying their inhibition of 5-LOX. These observations are useful for understanding the role of these compounds in disease prevention and therapy.

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Untargeted serum metabolites profiling in high-fat diet mice supplemented with enhanced palm tocotrienol-rich fraction using UHPLC-MS

Danial Efendy Goon, Sharaniza Ab-Rahim, Amir Hakimi Mohd Sakri, Musalmah Mazlan, Jen Kit Tan, Mardiana Abdul Aziz, Norizal Mohd Noor, Effendi Ibrahim, Siti Hamimah Sheikh Abdul Kadir

Sci Rep . 2021 Oct 25;11(1):21001. doi: 10.1038/s41598-021-00454-9.

Abstract

Excessive high fat dietary intake promotes risk of developing non-alcoholic fatty liver disease (NAFLD) and predisposed with oxidative stress. Palm based tocotrienol-rich fraction (TRF) has been reported able to ameliorate oxidative stress but exhibited poor bioavailability. Thus, we investigated whether an enhanced formulation of TRF in combination with palm kernel oil (medium-chain triglycerides) (ETRF) could ameliorate the effect of high-fat diet (HFD) on leptin-deficient male mice. All the animals were divided into HFD only (HFD group), HFD supplemented with ETRF (ETRF group) and HFD supplemented with TRF (TRF group) and HFD supplemented with PKO (PKO group). After 6 weeks, sera were collected for untargeted metabolite profiling using UHPLC-Orbitrap MS. Univariate analysis unveiled alternation in metabolites for bile acids, amino acids, fatty acids, sphingolipids, and alkaloids. Bile acids, lysine, arachidonic acid, and sphingolipids were downregulated while xanthine and hypoxanthine were upregulated in TRF and ETRF group. The regulation of these metabolites suggests that ETRF may promote better fatty acid oxidation, reduce oxidative stress and pro-inflammatory metabolites and acts as anti-inflammatory in fatty liver compared to TRF. Metabolites regulated by ETRF also provide insight of its role in fatty liver. However, further investigation is warranted to identify the mechanisms involved.

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Vitamin E supplementation in inflammatory skin diseases

Enzo Berardesca, Norma Cameli

Dermatol Ther . 2021 Oct 16;e15160. doi: 10.1111/dth.15160. Online ahead of print.

Abstract

Vitamin E is a powerful lipophilic antioxidant that protects membranes from lipid peroxidation, and consequently, oxidative damage. Oxidative stress plays a role in the development of neurodegenerative diseases. Vitamin E supplementation is recommended in patients with vitamin E deficiency due to fat malabsorption. The addition of vitamin E to the diet slows Alzheimer’s disease progression and protects older patients against respiratory infections. Recent studies also point to the involvement of oxidative stress in the pathology of immune-mediated skin diseases, such as atopic dermatitis and psoriasis. We reviewed the available clinical trials that investigated the role of vitamin E supplementation in preventing and treating atopic dermatitis and psoriasis. Data from these studies point to a positive role of vitamin E supplementation in these diseases. Still, due to limitations in study design, further evidence is needed to reach a definite conclusion.

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Modulation of NFκB signalling pathway by tocotrienol: A systematic review

Nurul Alimah Abdul Nasir, Muhammad Zulfiqah Sadikan, Renu Agarwal

Asia Pac J Clin Nutr . 2021 Sep;30(3):537-555. doi: 10.6133/apjcn.202109_30(3).0020.

Abstract

Tocotrienols have been reported to exert anticancer, anti-inflammatory, antioxidant, cardio-protective and boneprotective effects through modulation of NFκB signalling pathway. The objective of this systematic review is to evaluate available literature showing the effect of tocotrienols on NFκB signalling pathway and identify the potential mechanisms involved. A comprehensive search was conducted using PubMed and SCOPUS databases using the keywords “tocotrienol” and “NFκB” or “nuclear factor kappa b”. Main inclusion criteria were English language original articles showing the effect of tocotrienol on NFκB signalling pathway. Fifty-nine articles were selected from the total of 117 articles initially retrieved from the literature search. Modulation of regulatory proteins and genes such as inhibition of farnesyl prenyl transferase were found to be the mechanisms underlying the tocotrienol-induced suppression of NFκB activation.

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Exploration of Long-Chain Vitamin E Metabolites for the Discovery of a Highly Potent, Orally Effective, and Metabolically Stable 5-LOX Inhibitor that Limits Inflammation

Konstantin Neukirch, Khaled Alsabil, Chau-Phi Dinh, Rossella Bilancia, Martin Raasch, Alexia Ville, Ida Cerqua, Guillaume Viault, Dimitri Bréard, Simona Pace, Veronika Temml, Elena Brunner, Paul M Jordan, Marta C Marques, Konstantin Loeser, André Gollowitzer 1 2, Stephan Permann, Jana Gerstmeier, Stefan Lorkowski, Hermann Stuppner, Ulrike Garscha, Tiago Rodrigues, Gonçalo J L Bernardes, Daniela Schuster, Denis Séraphin, Pascal Richomme, Antonietta Rossi, Alexander S Mosig, Fiorentina Roviezzo, Oliver Werz, Jean-Jacques Helesbeux, Andreas Koeberle

J Med Chem . 2021 Aug 12;64(15):11496-11526. doi: 10.1021/acs.jmedchem.1c00806. Epub 2021 Jul 19.

Abstract

Endogenous long-chain metabolites of vitamin E (LCMs) mediate immune functions by targeting 5-lipoxygenase (5-LOX) and increasing the systemic concentrations of resolvin E3, a specialized proresolving lipid mediator. SAR studies on semisynthesized analogues highlight α-amplexichromanol (27a), which allosterically inhibits 5-LOX, being considerably more potent than endogenous LCMs in human primary immune cells and blood. Other enzymes within lipid mediator biosynthesis were not substantially inhibited, except for microsomal prostaglandin E2 synthase-1. Compound 27a is metabolized by sulfation and β-oxidation in human liver-on-chips and exhibits superior metabolic stability in mice over LCMs. Pharmacokinetic studies show distribution of 27a from plasma to the inflamed peritoneal cavity and lung. In parallel, 5-LOX-derived leukotriene levels decrease, and the inflammatory reaction is suppressed in reconstructed human epidermis, murine peritonitis, and experimental asthma in mice. Our study highlights 27a as an orally active, LCM-inspired drug candidate that limits inflammation with superior potency and metabolic stability to the endogenous lead.

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Effect of δ-Tocopherol on Mice Adipose Tissues and Mice Adipocytes Induced Inflammation

Chikako Kiyose, Haruka Takeuchi, Yoshimi Yabe, Tomoki Nojima, Mana Nagase, Chie Takahashi-Muto, Rieko Tanaka-Yachi

J Oleo Sci . 2021 Aug 6. doi: 10.5650/jos.ess21124. Online ahead of print.

Abstract

The study aim was to evaluate the potential anti-inflammatory effects of vitamin E analogs, especially α-tocopherol and δ-tocopherol. We used male C57BL/6JJcl mice, which were divided into four groups: the control (C), high-fat and high-sucrose diet (H), high-fat and high-sucrose diet+α-tocopherol (Ha) and high-fat and high-sucrose diet+δ-tocopherol (Hd) groups. The mice were fed for 16 weeks. To the high-fat and high-sucrose diet, 800 mg/kg of α-tocopherol or δ-tocopherol was added more. The final body weight was significantly higher in the H group than in the C group. On the other hand, the final body weight was drastically lower in the Ha group and Hd group than in the H group. However, the energy intake was not significantly different among all groups. Therefore, we assumed that α-tocopherol and δ-tocopherol have potential anti-obesity effect. Besides, inflammatory cytokine gene expression was significantly higher in the epididymal fat of the H group than in the C group. These results showed that inflammation was induced by epididymal fat of mice fed a high-fat and high-sucrose diet for 16 weeks. Unfortunately, addition of α-tocopherol or δ-tocopherol to the diet did not restrain inflammation of epididymal fat. Investigation of the anti-inflammatory effects of α-tocopherol or δ-tocopherol in co-cultured 3T3-L1 cells and RAW264.7 cells showed that δ-tocopherol inhibited increased gene expression of the inflammatory cytokines, IL-1β, IL-6, and iNOS. These results suggest that an anti-inflammatory effect in the δ-tocopherol is stronger than that in the α-tocopherol in vitro. We intend to perform an experiment by in vivo sequentially in the future.

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Effects of Co-administration of Vitamin E and Lithium Chloride on Chronic Constriction Injury-induced Neuropathy in Male Wistar Rats: Focus on antioxidant and anti-inflammatory mechanisms

Kingsley Dominic Esu, Ahmed Olalekan Bakare, Bamidele Victor Owoyele

Pain Pract . 2021 Aug 5. doi: 10.1111/papr.13064. Online ahead of print.

Abstract

Objectives: This study investigated the antinociceptive effects of co-administration of lithium chloride (LiCl) and vitamin E (Vit. E) on chronic constriction injury (CCI)-induced peripheral neuropathy in male Wistar rats. It further explored the anti-inflammatory and neuroprotective properties of LiCl and Vit. E which may be complementary to the antinociceptive effects of the two substances.

Methods: Thirty-six male Wistar rats, 190.00 ± 10.00 g of body weight (b.w) were randomly assigned to six experimental groups and administered with either normal saline, Vit. E, LiCl, or their combination, once daily for twenty-one (21) days. CCI was used to induce NP and mechanical allodynia was assessed using von Frey filaments and pinprick test. Open field maze (OFM) was used to assess the exploratory behaviour. Biochemical parameters were assessed in the dorsal root ganglion (DRG) after twenty-one days of treatment.

Results: Mechanical allodynia was developed in rats following CCI. Co-administration of LiCl and Vit.E. synergistically reduced mechanical hyperalgesia in rats which were significantly different compared with the single administration of either Vit.E. or LiCl. Combined doses of Vit.E. and LiCl significantly increases the explorative behaviour in the OFM. CCI increased malondialdehyde (MDA), tumour necrotic factor-alpha (TNF-α), calcitonin gene-related polypeptide (CGRP), calcium ion (Ca2+ ), and reduced superoxide dismutase (SOD) activities. Co-administration of LiCl and Vit.E. significantly reduced MDA, TNF-α, but increased SOD compared with ligated control.

Discussion: The findings revealed that the synergistic effects of the co-administration of Vit. E and LiCl in ameliorating neuropathic pain are mediated by their anti-inflammatory and antioxidant properties.

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Controlled Release of the α-Tocopherol-Derived Metabolite α-13′-Carboxychromanol from Bacterial Nanocellulose Wound Cover Improves Wound Healing

Jessica Hoff, Berit Karl, Jana Gerstmeier, Uwe Beekmann, Lisa Schmölz, Friedemann Börner, Dana Kralisch, Michael Bauer, Oliver Werz, Dagmar Fischer, Stefan Lorkowski, Adrian T Press

Nanomaterials (Basel) . 2021 Jul 28;11(8):1939. doi: 10.3390/nano11081939.

Abstract

Inflammation is a hallmark of tissue remodeling during wound healing. The inflammatory response to wounds is tightly controlled and well-coordinated; dysregulation compromises wound healing and causes persistent inflammation. Topical application of natural anti-inflammatory products may improve wound healing, in particular under chronic pathological conditions. The long-chain metabolites of vitamin E (LCM) are bioactive molecules that mediate cellular effects via oxidative stress signaling as well as anti-inflammatory pathways. However, the effect of LCM on wound healing has not been investigated. We administered the α-tocopherol-derived LCMs α-13′-hydroxychromanol (α-13′-OH) and α-13′-carboxychromanol (α-13′-COOH) as well as the natural product garcinoic acid, a δ-tocotrienol derivative, in different pharmaceutical formulations directly to wounds using a splinted wound mouse model to investigate their effects on the wounds’ proinflammatory microenvironment and wound healing. Garcinoic acid and, in particular, α-13′-COOH accelerated wound healing and quality of the newly formed tissue. We next loaded bacterial nanocellulose (BNC), a valuable nanomaterial used as a wound dressing with high potential for drug delivery, with α-13′-COOH. The controlled release of α-13′-COOH using BNC promoted wound healing and wound closure, mainly when a diabetic condition was induced before the injury. This study highlights the potential of α-13′-COOH combined with BNC as a potential active wound dressing for the advanced therapy of skin injuries.

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Effects of tocotrienols supplementation on markers of inflammation and oxidative stress: A systematic review and meta-analysis of randomized controlled trials

Ban-Hock Khor, Hui-Ci Tiong, Shing Cheng Tan, Sok Kuan Wong, Kok-Yong Chin, Tilakavati Karupaiah, Soelaiman Ima-Nirwana, Abdul Halim Abdul Gafor

PLoS One . 2021 Jul 23;16(7):e0255205. doi: 10.1371/journal.pone.0255205. eCollection 2021.

Abstract

Studies investigating the effects of tocotrienols on inflammation and oxidative stress have yielded inconsistent results. This systematic review and meta-analysis aimed to evaluate the effects of tocotrienols supplementation on inflammatory and oxidative stress biomarkers. We searched PubMed, Scopus, and Cochrane Central Register of Controlled Trials from inception until 13 July 2020 to identify randomized controlled trials supplementing tocotrienols and reporting circulating inflammatory or oxidative stress outcomes. Weighted mean difference (WMD) and corresponding 95% confidence interval (CI) were determined by pooling eligible studies. Nineteen studies were included for qualitative analysis, and 13 studies were included for the meta-analyses. A significant reduction in C-reactive protein levels (WMD: -0.52 mg/L, 95% CI: -0.73, -0.32, p < 0.001) following tocotrienols supplementation was observed, but this finding was attributed to a single study using δ-tocotrienols, not mixed tocotrienols. There were no effects on interleukin-6 (WMD: 0.03 pg/mL, 95% CI: -1.51, 1.58, p = 0.966), tumor necrosis factor-alpha (WMD: -0.28 pg/mL, 95% CI: -1.24, 0.68, p = 0.571), and malondialdehyde (WMD: -0.42 μmol/L, 95% CI: -1.05, 0.21, p = 0.189). A subgroup analysis suggested that tocotrienols at 400 mg/day might reduce malondialdehyde levels (WMD: -0.90 μmol/L, 95% CI: -1.20, -0.59, p < 0.001). Future well-designed studies are warranted to confirm the effects of tocotrienols on inflammatory and oxidative stress biomarkers, particularly on different types and dosages of supplementation. PROSPERO registration number: CRD42020198241.

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