Inhibition of Osteocyte Membrane Repair Activity via Dietary Vitamin E Deprivation Impairs Osteocyte Survival

Hagan ML1, Bahraini A, Pierce JL, Bass SM1, Yu K, Elsayed R, Elsalanty M, Johnson MH3, McNeil A, McNeil PL, McGee-Lawrence ME

Calcif Tissue Int. 2018 Oct 24. doi: 10.1007/s00223-018-0487-0. [Epub ahead of print]

Abstract

Osteocytes experience plasma membrane disruptions (PMD) that initiate mechanotransduction both in vitro and in vivo in response to mechanical loading, suggesting that osteocytes use PMD to sense and adapt to mechanical stimuli. PMD repair is crucial for cell survival; antioxidants (e.g., alpha-tocopherol, also known as Vitamin E) promote repair while reactive oxygen species (ROS), which can accumulate during exercise, inhibit repair. The goal of this study was to determine whether depleting Vitamin E in the diet would impact osteocyte survival and bone adaptation with loading. Male CD-1 mice (3 weeks old) were fed either a regular diet (RD) or Vitamin E-deficient diet (VEDD) for up to 11 weeks. Mice from each dietary group either served as sedentary controls with normal cage activity, or were subjected to treadmill exercise (one bout of exercise or daily exercise for 5 weeks). VEDD-fed mice showed more PMD-affected osteocytes (+ 50%) after a single exercise bout suggesting impaired PMD repair following Vitamin E deprivation. After 5 weeks of daily exercise, VEDD mice failed to show an exercise-induced increase in osteocyte PMD formation, and showed signs of increased osteocytic oxidative stress and impaired osteocyte survival. Surprisingly, exercise-induced increases in cortical bone formation rate were only significant for VEDD-fed mice. This result may be consistent with previous studies in skeletal muscle, where myocyte PMD repair failure (e.g., with muscular dystrophy) initially triggers hypertrophy but later leads to widespread degeneration. In vitro, mechanically wounded MLO-Y4 cells displayed increased post-wounding necrosis (+ 40-fold) in the presence of H₂O₂, which could be prevented by Vitamin E pre-treatment. Taken together, our data support the idea that antioxidant-influenced osteocyte membrane repair is a vital aspect of bone mechanosensation in the osteocytic control of PMD-driven bone adaptation.

Sajjad S, Malik H, Saeed L, Hashim I, Farooq U, Manzoor F

Physiol Res. 2018 Oct 23. [Epub ahead of print]

Abstract

Current study evaluated the synergistic potential of propolis and Vitamin E against sublethal toxicity of aluminum chloride on different biochemical parameters and liver histology. Swiss albino mice (n=42) were randomly divided into five groups. Group I received 0.2 ml of 0.9 % saline solution, Group II received Propolis (50 mg/kg b.w.), Group III received Vitamin E (150 mg/kg b.w.), Group IV received AlCl3 50 mg/kg b.w., Group V received AlCl3 + Propolis, Group VI received AlCl3 + Vitamin E and Group VI received AlCl3 + propolis + Vitamin E. Blood and tissue samples were collected after 7 and 21 days. The body weight of the animals significantly increased in all groups except group IV. The concentration of serum high density lipoprotein significantly decreased in group IV and increased in group V, VI and VII. The level of aspartate aminotransferase, alanine transferase, alkaline phosphatase, triglycerides, total cholesterol, and low density lipoprotein significantly increased in AlCl3 treated group and increased in group V, VI and VII. Tissue sections were processed and stained by hematoxylin and eosin. Group II showed cellular necrosis. Group V, VI showed decreased number of vacuolization, sinusoidal spacing and macrophage cell infiltration. Group VI showed less degenerative changes in the third week. Vitamin E and propolis in combination with Al provides more protection against AlCl3 induced toxicity.

Ambrogini P, Albertini MC, Betti M, Galati C, Lattanzi D, Savelli D, Di Palma M, Saccomanno S, Bartolini D, Torquato P, Ruffolo G, Olivieri F, Galli F, Palma E, Minelli A, Cuppini R

Mol Neurobiol. 2018 Oct;55(10):7822-7838. doi: 10.1007/s12035-018-0946-7. Epub 2018 Feb 22.

Abstract

Seizure-triggered maladaptive neural plasticity and neuroinflammation occur during the latent period as a key underlying event in epilepsy chronicization. Previously, we showed that α-tocopherol (α-T) reduces hippocampal neuroglial activation and neurodegeneration in the rat model of kainic acid (KA)-induced status epilepticus (SE). These findings allowed us to postulate an antiepileptogenic potential for α-T in hippocampal excitotoxicity, in line with clinical evidence showing that α-T improves seizure control in drug-resistant patients. To explore neurobiological correlates of the α-T antiepileptogenic role, rats were injected with such vitamin during the latent period starting right after KA-induced SE, and the effects on circuitry excitability, neuroinflammation, neuronal death, and microRNA (miRNA) expression were investigated in the hippocampus. Results show that in α-T-treated epileptic rats, (1) the number of population spikes elicited by pyramidal neurons, as well as the latency to the onset of epileptiform-like network activity recover to control levels; (2) neuronal death is almost prevented; (3) down-regulation of claudin, a blood-brain barrier protein, is fully reversed; (4) neuroinflammation processes are quenched (as indicated by the decrease of TNF-α, IL-1β, GFAP, IBA-1, and increase of IL-6); (5) miR-146a, miR-124, and miR-126 expression is coherently modulated in hippocampus and serum by α-T. These findings support the potential of a timely intervention with α-T in clinical management of SE to reduce epileptogenesis, thus preventing chronic epilepsy development. In addition, we suggest that the analysis of miRNA levels in serum could provide clinicians with a tool to evaluate disease evolution and the efficacy of α-T therapy in SE.

Anoushirvani AA, Poorsaadat L, Aghabozorgi R, Kasravi M

Open Access Maced J Med Sci. 2018 Oct 21;6(10):1857-1861. doi: 10.3889/oamjms.2018.333. eCollection 2018 Oct 25.

Abstract

BACKGROUND:

Paclitaxel-induced peripheral neuropathy is the most important side effect limiting the use of this medication.

AIM:

This study aimed to compare the effects of omega-3 and vitamin E on the incidence of peripheral neuropathy in patients receiving Taxol.

METHODS:

In this clinical trial, 63 patients who were a candidate for receiving taxol, were enrolled based on inclusion and exclusion criteria. In group O, patients received 640 mg omega-3 three times a day, and group E, received 300 mg vitamin E two times a day. Patients took the supplements up to three months after the onset of Taxol. Group P received placebo for a similar period. All patients referred to a neurologist for electrophysiological evaluation before the onset of chemotherapy and at months 1 and 3. The presence of neuropathy and its progression was recorded by the neurologist.

RESULTS:

Neurological examination in this study indicated that 6 patients (28.6%) in Group O, 7 patients (33.3%) in group E, and 15 patients (71.4%) in placebo group started peripheral neuropathy. There was a significant difference between intervention groups and the placebo group (p = 0.0001) and no significant difference between intervention groups (p = 0.751).

CONCLUSION:

Our data suggested that vitamin E and omega-3 may significantly reduce the incidence of Paclitaxel-induced peripheral neuropathy. Routine administration of such supplements that have no special side effect for patients under chemotherapy may greatly enhance their quality of life.

Chalouati H, Ben Sâad MM, Payrastre L

Toxicol Mech Methods. 2018 Oct 3:1-8. doi: 10.1080/15376516.2018.1506847. [Epub ahead of print]

Abstract

The protective effects of α-Tocopherol (vitamin E) on liver injury induced by hexachlorobenzene (HCB) were investigated in adult male rats of Wistar strain. Animals were randomly divided into six groups of eight rats each. Group 1 and 2 have received HCB, dissolved in olive oil, at a dose of 4 mg or 16 mg/kg b.w., respectively. Group 3 and 4 were treated by the same doses of HCB (4 mg and 16 mg/kg b.w.) after 1 h of pretreatment with α-tocopherol at a dose of 100 mg kg^-1 b.w. The other two groups served as controls; which received either olive oil only, a solvent of HCB, or α-tocopherol. A significant increase in hepatic lipid peroxidation (LPO) and GSH activity were observed following HCB administration. The activities of antioxidant enzymes like superoxide dismutase and catalase were significantly decreased while glutathione peroxidase was significantly increased following HCB administration. Similarly, a significant increase in plasma levels of various marker enzymes [aminotransferase (aspartate aminotransférase (AST) and alanine aminotransferase (ALT)), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH)] and a decrease of total protein level were observed. Pretreatment with vitamin E of HCB treated rats ameliorated all biochemical parameters to near normal values. Liver histological study confirmed biochemical parameters and the beneficial role of vitamin E.

Singh I, Nair RS, Gan S, Cheong V, Morris A

Pharm Dev Technol. 2018 Oct 3:1-7. doi: 10.1080/10837450.2018.1509347. [Epub ahead of print]

Abstract

The drawbacks associated with chemical skin permeation enhancers such as skin irritation and toxicity necessitated the research to focus on potential permeation enhancers with a perceived lower toxicity. Crude palm oil (CPO) is obtained by direct compression of the mesocarp of the fruit of the oil palm belonging to the genus Elaeis. In this research, CPO and tocotrienol-rich fraction (TRF) of palm oil were evaluated for the first time as skin permeation enhancers using full-thickness human skin. The in vitro permeation experiments were conducted using excised human skin mounted in static upright ‘Franz-type’ diffusion cells. The drugs selected to evaluate the enhancing effects of these palm oil derivatives were 5-fluorouracil, lidocaine and ibuprofen: compounds covering a wide range of Log p values. It was demonstrated that CPO and TRF were capable of enhancing the percutaneous permeation of drugs across full-thickness human skin in vitro. Both TRF and CPO were shown to significantly enhance the permeation of ibuprofen with flux values of 30.6 µg/cm² h and 23.0 µg/cm² h respectively, compared to the control with a flux of 16.2 µg/cm² h. The outcome of this research opens further scope for investigation on the transdermal penetration enhancement activity of pure compounds derived from palm oil.

Kimura Y, Asa M, Urano Y, Saito Y, Nishikawa K, Noguchi N

Biochimie. 2018 Oct;153:203-209. doi: 10.1016/j.biochi.2018.07.004. Epub 2018 Jul 7.

Abstract

Although 24(S)-hydroxycholesterol (24S-OHC) plays an important role to maintain homeostasis of cholesterol in the brain, it induces neuronal cell death at high concentrations. 24S-OHC-induced cell death was suppressed by γ-tocopherol (γ-Toc) but not by γ-tocotrienol (γ-Toc3) in a similar way to α-tocopherol (α-Toc) and α-tocotrienol (α-Toc3) in human neuroblastoma SH-SY5Y cells. Both γ-Toc and γ-Toc3 significantly inhibited cumene hydroperoxide-induced cell death, as previously shown in the case of α-Toc and α-Toc3. Lipid droplet-like structure formation induced by 24S-OHC was suppressed by neither γ-Toc nor γ-Toc3. The phosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII) was induced by 24S-OHC, which was suppressed by CaMKII phosphorylation-site inhibitor mM3 but not by calmodulin-binding-site inhibitor KN62. A calcium chelator, BAPTA-AM, inhibited calcium ionophore A23187-induced CaMKII phosphorylation but not 24S-OHC-induced CaMKII phosphorylation. Receptor-interacting protein kinase 1 (RIPK1) phosphorylation induced by 24S-OHC was not inhibited by either mM3 or KN62, suggesting that CaMKII activation does not affect RIPK1 phosphorylation. Knockdown of RIPK1 using siRNA induced not only inhibition of CaMKII phosphorylation but also reduction of total CaMKII protein levels, suggesting that RIPK1 may regulate CaMKII signalling. 24S-OHC-induced RIPK1 phosphorylation was inhibited by neither α-Toc nor α-Toc3. In contrast, CaMKII phosphorylation induced by 24S-OHC was significantly suppressed by α-Toc but not by α-Toc3. These results suggest that CaMKII activation is involved in the mechanism of 24S-OHC-induced cell death and that Toc inhibits the cell death via inhibition of CaMKII activation through a RIPK1 phosphorylation-independent pathway.

Antosik A, Czubak K, Cichon N, Nowak P, Zbikowska H

Transfus Med Hemother. 2018 Oct;45(5):347-354. doi: 10.1159/000486605. Epub 2018 Mar 9

Abstract

BACKGROUND:

To investigate i) the effects of Trolox® or mannitol, which represent two different classes of antioxidants, on oxidative changes generated in manually isolated red blood cells (RBCs) from citrate-phosphate-dextrose (CPD) preserved whole blood, followed by up to 20 days refrigerated storage, and ii) whether Trolox supplemented to the blood bank-manufactured saline-adenine-glucose-mannitol (SAGM) preserved RBC units would offer better storage conditions compared with SAGM alone.

METHODS:

The percentage of hemolysis and extracellular activity of lactate dehydrogenase (LDH) was measured to assess RBC membrane integrity. Lipid peroxidation, reduced glutathione (GSH) levels and total antioxidant capacity (TAC) were quantified by thiobarbituric acid-reactive substances (TBARS), Ellman’s reagent and 2, 2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS^.+) based assay, respectively.

RESULTS:

Trolox was little more effective than mannitol in protecting against progressive RBC hemolysis. Trolox (0.125-3.125 mmol/l) inhibited storage-induced leakage of LDH, lipid peroxidation, and to a lesser extent GSH depletion. Mannitol at these concentrations neither inhibited TBARS formation nor prevented GSH depletion. RBC units stored in SAGM-Trolox had significantly lower hemolysis, LDH leakage, and lipid peroxidation level compared to RBCs stored in SAGM.

CONCLUSION:

There is evidence of the beneficial effects of supplementing RBC-additive solutions with membrane-interacting antioxidants such as vitamin E analogues.