Effects of vitamin A and vitamin E on attenuation of titanium dioxide nanoparticles-induced toxicity in the liver of male Wistar rats

Moradi A, Ziamajidi N, Ghafourikhosroshahi A, Abbasalipourkabir R

Mol Biol Rep. 2019 Jun;46(3):2919-2932. doi: 10.1007/s11033-019-04752-4. Epub 2019 Mar 18.

Abstract

The increasing application of titanium dioxide nanoparticles (NTiO₂) in life and the toxicity potential of these nanoparticles have raised concerns about their detrimental effects on human health. This study was conducted to investigate the hepatoprotective effects of vitamin Eand vitamin A against hepatotoxicity induced by NTiO₂ in rats. Thirty-six male Wistar rats were randomly divided into six groups of six rats each. Intoxicated group received 300 mg/kg NTiO₂ for two weeks by gavage. Groups treated with vitamin E (100 IU/kg), vitamin A (100 IU/kg) and mixture of these vitamins were orally administered for 3 weeks (started 7 days before NTiO₂ administration). In order to investigate the redox changes, total antioxidant capacity, total oxidant status, and lipid peroxidation were determined in liver tissue as well as activity of antioxidant enzymes including superoxide dismutase, glutathione peroxidase, and catalase. In addition, inflammatory responses were assessed by measuring the expression of NF-κB (mRNA) and TNF-α (mRNA and protein). Histopathological analysis and measurement of liver enzymes (ALP, ALT, AST, and LDH in serum) were also done to determine hepatic injury. In liver, NTiO₂ caused hepatic injury, redox perturbation, and reduction of antioxidant enzymes and elevation of inflammatory mediators, significantly. However, treatment with vitamins was able to significantly ameliorate these alterations. This study highlights the antioxidant and anti-inflammatory properties of vitamins A and E against toxicity of NTiO₂ and poses the use of these vitamins to mitigate the toxic effects of this nanoparticles in NTiO₂-contained products.

Yumusak N, Sadic M, Akbulut A, Aydinbelge FN, Koca G, Korkmaz M

Bratisl Lek Listy. 2019;120(4):263-269. doi: 10.4149/BLL_2019_048.

Abstract

OBJECTIVES:

The aim of the present study was to investigate the radioprotective effect of vitamin E in the prevention of radioiodine (RAI) induced gastrointestinal damage.

METHOD:

Twenty-four rats were randomly divided into three groups as follows: Group-1 was untreated control group, Group-2 was orally administered single dose of 111 MBq RAI, and Group-3 was orally administered 111 MBq RAI and 1 mL of oral vitamin E. Vitamin E was started two days before RAI administration and was continued for five days once daily after RAI. Pathomorphological parameters of gastrointestinal tissues (stomach, small intestines and bowels) were measured using Hematoxylin-Eosin and Masson’s trichrome staining.

RESULTS:

Varying degrees of inflammation, edema, ulcer, mucosal degeneration, necrosis and fibrosis were seen in the stomach, small intestine and bowel tissues of the rats in both study groups and not in the control group. The differences were statistically significant between these groups for all parameters (p < 0.05). The histopathological damage in the vitamin E treated group was significantly less than the damage in the RAI only group (p < 0.05 for all pathomorphological parameters).

CONCLUSION:

The results of this study showed that vitamin E has a radioprotective property with antiinflammatory and antifibrotic effects protecting against gastrointestinal damage caused by radioiodine.

Ranard KM, Kuchan MJ, Erdman JW Jr

Lipids. 2019 May;54(5):289-299. doi: 10.1002/lipd.12149. Epub 2019 Apr 16.

Abstract

Of the antioxidant vitamin E isoforms, α-tocopherol (αT) and γ-tocopherol (γT) are the most abundant in the human diet, and αT is consumed from both natural and synthetic sources. αT and γT may differentially impact inflammation and influence cardiovascular outcomes, in part by modulating gene expression. The goal of this study was to compare the effects of natural αT, synthetic αT, and γT on gene expression in two human cell lines. Human aortic smooth muscle cells (HASMC) and endothelial cells (HAEC) were either: (1) treated with 25 μM tocopherolsalone, or (2) pretreated with tocopherols prior to a pro-inflammatory cytokine (tumor necrosis factor-alpha, TNF-α) stimulation. The expression of atherosclerosis-related genes was measured using RT² Profiler PCR arrays. Tocopherol treatments alone did not significantly modulate the expression of genes in unstimulated HASMC or HAEC. TNF-α stimulation significantly upregulated genes involved with apoptosis and stress response in both cell lines. Pretreating cells with tocopherols did not normalize the gene expression changes induced by TNF-α. However, αT pretreatments, but not γT pretreatments, attenuated TNF expression in both HASMC and HAEC. These findings suggest that under stimulated conditions, αT modestly modulates the expression of selective genes and that αT may be more anti-inflammatory than γT.

Ranard KM, Kuchan MJ, Erdman JW Jr

Lipids. 2019 Apr 16. doi: 10.1002/lipd.12149. [Epub ahead of print]

Abstract

Zainal Z, Abdul Rahim A, Khaza'ai H, Chang SK

Int J Mol Sci. 2019 Apr 10;20(7). pii: E1764. doi: 10.3390/ijms20071764.

Abstract

Synthetic therapeutic drugs for asthma, a chronic airway inflammation characterised by strong eosinophil, mast cell, and lymphocyte infiltration, mucus hyper-production, and airway hyper-responsiveness, exhibit numerous side effects. Alternatively, the high antioxidant potential of palm oil phytonutrients, including vitamin E (tocotrienol-rich fractions; TRF) and carotene, may be beneficial for alleviating asthma. Here, we determined the therapeutic efficacy of TRF, carotene, and dexamethasone in ovalbumin-challenged allergic asthma in Brown Norway rats. Asthmatic symptoms fully developed within 8 days after the second sensitization, and were preserved throughout the time course via intranasal ovalbumin re-challenge. Asthmatic rats were then orally administered 30 mg/kg body weight TRF or carotene. TRF-treated animals exhibited reduced inflammatory cells in bronchial alveolar lavage fluid. TRF- and carotene-treated rats exhibited notable white blood cell reduction comparable to that from dexamethasone. TRF- and carotene-treatment also downregulated pro-inflammatory markers (IL-β, IL-6, TNF-α), coincident with anti-inflammatory marker IL-4 and IL-13 upregulation. Treatment significantly reduced asthmatic rat plasma CRP and IgE, signifying improved systemic inflammation. Asthmatic lung histology displayed severe edema and inflammatory cell infiltration in the bronchial wall, whereas treated animals retained healthy, normal-appearing lungs. The phytonutrients tocotrienol and carotene thus exhibit potential benefits for consumption as nutritional adjuncts in asthmatic disease.

Takahashi K, Yanai S, Takisawa S, Kono N, Arai H, Nishida Y, Yokota T, Endo S, Ishigami A

Arch Biochem Biophys. 2019 Mar 15;663:120-128. doi: 10.1016/j.abb.2019.01.003. Epub 2019 Jan 8.

Abstract

BACKGROUND:

Vitamin C (l-ascorbic acid, VC) and vitamin E (α-tocopherol, VE) play important physiological roles as endogenous antioxidants in many tissues and organs. However, their roles in the brain remain entirely elusive. We established senescence marker protein 30 (SMP30)/α-tocopherol transfer protein (αTTP) double knockout (DKO) mice as a novel VC and VE double-deficiency model and examined the effect of VC and VE double-deficiency on brain functions.

METHODS:

DKO and wild-type (WT) mice were divided into the following two groups: mice in the CE (+) group were supplied with sufficient amounts of VC and VE and mice in the CE (-) group were deficient in both VC and VE. After 8 weeks of CE (+) or CE (-) treatments, a battery of behavioral experiments was conducted to analyze cognitive functions, including memory, through the Morris water maze and Pavlovian fear conditioning tasks.

RESULTS:

The plasma VC and VE levels in DKO-CE (-) mice and VE level in WT-CE (-) mice were almost completely depleted after 8 weeks of the deficient treatment. The behavioral study revealed that the general behaviors, including locomotor activity and anxiety level, were not influenced by the CE (-) treatment in DKO and WT mice. However, in the Pavlovian fear conditioning task, DKO-CE (-) mice showed impaired conditioned fear memory compared with that of DKO-CE (+) mice. Furthermore, increased mRNA expression was observed in inflammatory-related genes, such as IL-6, TNFα, F4/80, and Mcp-1, in the hippocampus of DKO-CE (-) mice.

CONCLUSIONS:

The findings of this study provide evidence that VC and VE deficiency led to impaired conditioned fear memory possibly caused by neuroinflammation in the brain.

Ghani SMA, Goon JA, Azman NHEN, Zakaria SNA, Hamid Z, Ngah WZW

Clinics (Sao Paulo). 2019 Mar 7;74:e688. doi: 10.6061/clinics/2019/e688.

Abstract

OBJECTIVES:

This study aims to compare the differential gene expression resulting from tocotrienol-rich fraction and α-tocopherol supplementation in healthy older adults.

METHODS:

A total of 71 eligible subjects aged 50 to 55 years from Gombak and Kuala Lumpur, Malaysia, were divided into three groups and supplemented with placebo (n=23), α-tocopherol (n=24) or tocotrienol-rich fraction (n=24). Blood samples were collected at baseline and at 3 and 6 months of supplementation for microarray analysis.

RESULTS:

The number of genes altered by α-tocopherol was higher after 6 months (1,410) than after 3 months (273) of supplementation. α-Tocopherol altered the expression of more genes in males (952) than in females (731). Similarly, tocotrienol-rich fraction modulated the expression of more genes after 6 months (1,084) than after 3 months (596) and affected more genes in males (899) than in females (781). α-Tocopherol supplementation modulated pathways involving the response to stress and stimuli, the immune response, the response to hypoxia and bacteria, the metabolism of toxins and xenobiotics, mitosis, and synaptic transmission as well as activated the mitogen-activated protein kinase and complement pathways after 6 months. However, tocotrienol-rich fraction supplementation affected pathways such as the signal transduction, apoptosis, nuclear factor kappa B kinase, cascade extracellular signal-regulated kinase-1 and extracellular signal-regulated kinase-2, immune response, response to drug, cell adhesion, multicellular organismal development and G protein signaling pathways.

CONCLUSION:

Supplementation with either α-tocopherol or tocotrienol-rich fraction affected the immune and drug response and the cell adhesion and signal transduction pathways but modulated other pathways differently after 6 months of supplementation, with sex-specific responses.

Rodriguez-Duarte J, Galliussi G, Dapueto R, Rossello J, Malacrida L, Kamaid A, Schopfer FJ, Escande C, López GV, Batthyány C

Br J Pharmacol. 2019 Mar;176(6):757-772. doi: 10.1111/bph.14561. Epub 2019 Feb 3.

Abstract

BACKGROUND AND PURPOSE:

Atherosclerosis is characterized by chronic low-grade inflammation with concomitant lipid accumulation in the arterial wall. Anti-inflammatory and anti-atherogenic properties have been described for a novel class of endogenous nitroalkenes (nitrated-unsaturated fatty acids), formed during inflammation and digestion/absorption processes. The lipid-associated antioxidant α-tocopherol is transported systemically by LDL particles including to the atheroma lesions. To capitalize on the overlapping and complementary salutary properties of endogenous nitroalkenes and α-tocopherol, we designed and synthesized a novel nitroalkene-α-tocopherol analogue (NATOH) to address chronic inflammation and atherosclerosis, particularly at the lesion sites.

EXPERIMENTAL APPROACH:

We synthesized NATOH, determined its electrophilicity and antioxidant capacity and studied its effects over pro-inflammatory and cytoprotective pathways in macrophages in vitro. Moreover, we demonstrated its incorporation into lipoproteins and tissue both in vitro and in vivo, and determined its effect on atherosclerosis and inflammatory responses in vivo using the Apo E knockout mice model.

KEY RESULTS:

NATOH exhibited similar antioxidant capacity to α-tocopherol and, due to the presence of the nitroalkenyl group, like endogenous nitroalkenes, it exerted electrophilic reactivity. NATOH was incorporated in vivo into the VLDL/LDL lipoproteins particles to reach the atheroma lesions. Furthermore, oral administration of NATOH down-regulated NF-κB-dependent expression of pro-inflammatory markers (including IL-1β and adhesion molecules) and ameliorated atherosclerosis in Apo E knockout mice.

CONCLUSIONS AND IMPLICATIONS:

In toto, the data demonstrate a novel pharmacological strategy for the prevention of atherosclerosis based on a creative, natural and safe drug delivery system of a non-conventional anti-inflammatory compound (NATOH) with significant potential for clinical application.

Ran L, Liu AB, Lee MJ, Xie P, Lin Y, Yang CS

Biofactors. 2019 Jan 29. doi: 10.1002/biof.1492. [Epub ahead of print]

Abstract

Tocopherols (T) and tocotrienols (T3), all existing in α, β, γ, and δ-forms, are the eight forms of vitamin E (VE). In this study, we investigated the effects of gut microbiota on the degradation and tissue levels of different VE forms by treating mice with antibiotics in drinking water for 12 days. The mice also received an intragastric (i.g.) dose of VE mixture (mVE; α-T, γ-T, δ-T, γ-T3, and δ-T3, each at a dose of 75 mg/kg) every morning. Antibiotic treatment significantly increased the blood levels of all VE forms in mice that received an i.g. dose of mVE in the morning, 3 h before sacrifice. Without this morning dose, the blood levels of α-T were at the normal physiological levels, but those of the other VE forms were much lower; and the levels of all VE forms were not significantly affected by antibiotics. The liver levels of these VE forms were generally higher and followed the same pattern as the serum. On the contrary, the levels of most side-chain degradation metabolites of VE forms in the serum, liver, kidney, urine, and fecal samples were significantly decreased by antibiotics. The increased bioavailability of VE by antibiotics is probably due to increased absorption of VE or its decreased degradation by gut microbes. The results demonstrate the important roles of gut microbiota in the degradation of VE and in decreasing the bioavailabilities of VE forms.

Dobrzyński M, Kuropka P, Leśków A, Herman K, Tarnowska M, Wiglusz RJ

Adv Clin Exp Med. 2019 Jan 24. doi: 10.17219/acem/99613. [Epub ahead of print]

Abstract

BACKGROUND:

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can cause adverse effects in many organs. Toxic effects are caused due to the formation of a TCDD complex with the cytoplasmatic aryl hydrocarbon receptor (AhR), whose mechanism of action is similar to that of the estrogen receptor (ER). Some substances, including α-tocopherol (E) and acetylsalicylic acid (ASA), can reduce the toxic effects of TCDD in offspring.

OBJECTIVES:

The objective of this study was to evaluate the co-expression of AhR and ER in the incisors of rat offspring whose mothers were exposed to TCDD, using immunohistochemical and histological techniques. Moreover, the possible protective role of E and ASA was investigated.

MATERIAL AND METHODS:

Four groups of 2-day-old rat offspring, whose mothers were intoxicated by TCDD before mating, were established: control group (C), TCDD group, TCDD+E group and TCDD+ASA group.

RESULTS:

In the TCDD group, there was an increase in ER expression and a decrease in AhR expression in comparison with the C group. In the TCDD+E and TCDD+ASA groups, there was a weak or negative ER expression and slightly stronger expression of AhR than in the TCDD group.

CONCLUSIONS:

The co-expression of AhR and ER during tooth development suggests the role of AhR and ER in the control of this process. Both receptors are also involved in the process of detoxification of TCDD. The increase in AhR in TCDD+E and TCDD+ASA groups indicate a preventive action of antioxidant and antiinflammatory pharmaceutics, which may limit negative effects of TCDD.