Targeting melanoma stem cells with the Vitamin E derivative δ-tocotrienol

Marzagalli M, Moretti RM, Messi E, Marelli MM, Fontana F, Anastasia A, Bani MR, Beretta G, Limonta P

Sci Rep. 2018 Jan 12;8(1):587. doi: 10.1038/s41598-017-19057-4

Abstract

The prognosis of metastatic melanoma is very poor, due to the development of drug resistance. Cancer stem cells (CSCs) may play a crucial role in this mechanism, contributing to disease relapse. We first characterized CSCs in melanoma cell lines. We observed that A375 (but not BLM) cells are able to form melanospheres and show CSCs traits: expression of the pluripotency markers SOX2 and KLF4, higher invasiveness and tumor formation capability in vivo with respect to parental adherent cells. We also showed that a subpopulation of autofluorescent cells expressing the ABCG2 stem cell marker is present in the A375 spheroid culture. Based on these data, we investigated whether δ-TT might target melanoma CSCs. We demonstrated that melanoma cells escaping the antitumor activity of δ-TT are completely devoid of the ability to form melanospheres. In contrast, cells that escaped vemurafenib treatment show a higher ability to form melanospheres than control cells. δ-TT also induced disaggregation of A375 melanospheres and reduced the spheroidogenic ability of sphere-derived cells, reducing the expression of the ABCG2 marker. These data demonstrate that δ-TT exerts its antitumor activity by targeting the CSC subpopulation of A375 melanoma cells and might represent a novel chemopreventive/therapeutic strategy against melanoma.

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Tocotrienol supplementation suppressed bone resorption and oxidative stress in postmenopausal osteopenic women: a 12-week randomized double-blinded placebo-controlled trial.

Shen CL, Yang S, Tomison MD, Romero AW, Felton CK, Mo H

Osteoporos Int. 2018 Jan 12. doi: 10.1007/s00198-017-4356-x. [Epub ahead of print]

Abstract

Tocotrienols have shown bone-protective effect in animals. This study showed that a 12-week tocotrienol supplementation decreased concentrations of bone resorption biomarker and bone remodeling regulators via suppressing oxidative stress in postmenopausal osteopenic women.

INTRODUCTION:

Tocotrienols (TT) have been shown to benefit bone health in ovariectomized animals, a model of postmenopausal women. The purpose of this study was to evaluate the effect of 12-week TT supplementation on bone markers (serum bone-specific alkaline phosphatase (BALP), urine N-terminal telopeptide (NTX), serum soluble receptor activator of nuclear factor-kappaB ligand (sRANKL), and serum osteoprotegerin (OPG)), urine calcium, and an oxidative stress biomarker (8-hydroxy-2′-deoxyguanosine (8-OHdG)) in postmenopausal women with osteopenia.

METHODS:

Eighty-nine postmenopausal osteopenic women (59.7 ± 6.8 year, BMI 28.7 ± 5.7 kg/m2) were randomly assigned to three groups: (1) placebo (430 mg olive oil/day), (2) low TT (430 mg TT/day, 70% purity), and (3) high TT (860 mg TT/day, 70% purity). TT, an extract from annatto seed with 70% purity, consisted of 90% delta-TT and 10% gamma-TT. Overnight fasting blood and urine samples were collected at baseline, 6, and 12 weeks for biomarker analyses. Eighty-seven subjects completed the 12-week study.

RESULTS:

Relative to the placebo group, there were marginal decreases in serum BALP level in the TT-supplemented groups over the 12-week study period. Significant decreases in urine NTX levels, serum sRANKL, sRANKL/OPG ratio, and urine 8-OHdG concentrations and a significant increase in BALP/NTX ratio due to TT supplementation were observed. TT supplementation did not affect serum OPG concentrations or urine calcium levels throughout the study period. There were no significant differences in NTX level, BALP/NTX ratio, sRANKL level, and sRANKL/OPG ratio between low TT and high TT groups.

CONCLUSIONS:

Twelve-week annatto-extracted TT supplementation decreased bone resorption and improved bone turnover rate via suppressing bone remodeling regulators in postmenopausal women with osteopenia. Such osteoprotective TT’s effects may be, in part, mediated by an inhibition of oxidative stress.

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Vitamin E inhibits the UVAI induction of “light” and “dark” cyclobutane pyrimidine dimers, and oxidatively generated DNA damage, in keratinocytes

Delinasios GJ, Karbaschi M, Cooke MS, Young AR

Sci Rep. 2018 Jan 11;8(1):423. doi: 10.1038/s41598-017-18924-4.

Abstract

Solar ultraviolet radiation (UVR)-induced DNA damage has acute, and long-term adverse effects in the skin. This damage arises directly by absorption of UVR, and indirectly via photosensitization reactions. The aim of the present study was to assess the effects of vitamin E on UVAI-induced DNA damage in keratinocytes in vitro. Incubation with vitamin E before UVAI exposure decreased the formation of oxidized purines (with a decrease in intracellular oxidizing species), and cyclobutane pyrimidine dimers (CPD). A possible sunscreening effect was excluded when similar results were obtained following vitamin E addition after UVAI exposure. Our data showed that DNA damage by UVA-induced photosensitization reactions can be inhibited by the introduction of vitamin E either pre- or post-irradiation, for both oxidized purines and CPD (including so-called “dark” CPDs). These data validate the evidence that some CPD are induced by UVAI initially via photosensitization, and some via chemoexcitation, and support the evidence that vitamin E can intervene in this pathway to prevent CPD formation in keratinocytes. We propose the inclusion of similar agents into topical sunscreens and aftersun preparations which, for the latter in particular, represents a means to mitigate on-going DNA damage formation, even after sun exposure has ended.

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Ischemia-Reperfusion Injury of Sciatic Nerve in Rats: Protective Role of Combination of Vitamin C with E and Tissue Plasminogen Activator

Apostolopoulou K, Konstantinou D, Alataki R, Papapostolou I, Zisimopoulos D, Kalaitzopoulou E, Bravou V, Lilis I, Angelatou F, Papadaki H, Georgiou CD, Chroni E

Neurochem Res. 2018 Jan 11. doi: 10.1007/s11064-017-2465-8. [Epub ahead of print]

Abstract

An ischemia/reperfusion injury of rat’s sciatic nerve was experimentally developed. In this model, we measured the in vivo production of superoxide radical, as a marker of oxidative stress and the occludin expression as an indicator of blood-nerve barrier function and we examined potential protective innervations against these abnormalities. Right sciatic nerves of the animals underwent 3 h of ischemia followed by 7 days of reperfusion and were divided into three groups: ischemic, pretreated with vitamin C in conjunction with vitamin E and treated with tissue plasminogen activator. Compared to measurements from left sciatic nerves used as sham, the ischemic group showed significantly increased superoxide radical and reduced expression of occludin in western blot and immunohistochemistry. No such differences were detected between sham and nerves in the vitamin or tissue plasminogen activator groups. It is suggested that the experimental ischemia/reperfusion model was suitable for studying the relationship between oxidative state and blood-nerve barrier. The reversion of abnormalities by the applied neuroprotective agents might prove to be a clinically important finding in view of the implication of vascular supply derangement in various neuropathies in humans.

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The use of 99mTc-phytate for assessment the protective effect of vitamin E against hepatotoxicity induced by methotrexat in rat

Amirfakhrian H, Abedi SM, Sadeghi H, Azizi S, Hosseinimehr SJ

Nucl Med Rev Cent East Eur. 2018 Jan 10. doi: 10.5603/NMR.a2018.0006. [Epub ahead of print]

Abstract

In this study, we investigated the protective effect of vitamin E against methotrexate (MTX)-induced hepatotoxicity by quantitative liver 99mTc-phytate uptake and liver imaging and to compare its effect with histopathology in rat. Rats were divided into five groups as control, solvent, Vit E (100 mg/kg), MTX (20 mg/kg), Vit E + MTX and. Vit E was intraperitoneally administrated for 17 days before MTX injection and continued for 4 days. 99mTc-phytate was injected through the tail of rats after the drug administration. The percentage of the injected dose per gram of liver and spleen tissues (%ID/g) was calculated. Liver imaging was obtained with gamma camera. In other experiment, liver of treated rats were assessed for histopathology. 99mTc-phytate uptake per gram tissue of the livers as %ID/g in control, solvent, MTX, Vit E, Vit E + MTX and MTX groups were 8.99%  1.37, 8.53%  2.91, 8.65%  3.84, 3.22%  1.09 and 8.38%  2.68. Vit E administration with MTX resulted in a significant increasing in the level of %ID/g. Vit E treatment improved the shape of live in planner image. Histophatological examinations showed a protective effect of Vit E against MTX-induced hepatoxicity in rats. The results showed that Vit E significantly attenuates the MTX-induced hepatotoxicity in rats, and 99mTc-phytate uptake in liver as well as liver image to be acceptable techniques for assessment of liver and spleen damages and/or their tissues protective effects in animal model.

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Vitamin transporters in mice brain with aging

Marcos P, González-Fuentes J, Castro-Vázquez L, Lozano MV, Santander-Ortega MJ, Rodríguez-Robledo V, Villaseca-González N, Arroyo-Jiménez MM

J Anat. 2018 Jan 8. doi: 10.1111/joa.12769. [Epub ahead of print]

Abstract

Its high metabolic rate and high polyunsaturated fatty acid content make the brain very sensitive to oxidative damage. In the brain, neuronal metabolism occurs at a very high rate and generates considerable amounts of reactive oxygen species and free radicals, which accumulate inside neurons, leading to altered cellular homeostasis and integrity and eventually irreversible damage and cell death. A misbalance in redox metabolism and the subsequent neurodegeneration increase throughout the course of normal aging, leading to several age-related changes in learning and memory as well as motor functions. The neuroprotective function of antioxidants is crucial to maintain good brain homeostasis and adequate neuronal functions. Vitamins E and C are two important antioxidants that are taken up by brain cells via the specific carriers αTTP and SVCT2, respectively. The aim of this study was to use immunohistochemistry to determine the distribution pattern of these vitamin transporters in the brain in a mouse model that shows fewer signs of brain aging and a higher resistance to oxidative damage. Both carriers were distributed widely throughout the entire brain in a pattern that remained similar in 4-, 12-, 18- and 24-month-old mice. In general, αTTP and SVCT2 were located in the same regions, but they seemed to have complementary distribution patterns. Double-labeled cell bodies were detected only in the inferior colliculus, entorhinal cortex, dorsal subiculum, and several cortical areas. In addition, the presence of αTTP and SVCT2 in neurons was analyzed using double immunohistochemistry for NeuN and the results showed that αTTP but not SVCT2 was present in Bergmann’s glia. The presence of these transporters in brain regions implicated in learning, memory and motor control provides an anatomical basis that may explain the higher resistance of this animal model to brain oxidative stress, which is associated with better motor performance and learning abilities in old age.

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Vitamin E (α‑tocopherol) ameliorates aristolochic acid‑induced renal tubular epithelial cell death by attenuating oxidative stress and caspase‑3 activation.

Wu TK, Pan YR, Wang HF, Wei CW, Yu YL

Mol Med Rep. 2018 Jan;17(1):31-36. doi: 10.3892/mmr.2017.7921. Epub 2017 Oct 27.

Abstract

Aristolochic acid (AA) is a component identified in traditional Chinese remedies for the treatment of arthritic pain, coughs and gastrointestinal symptoms. However, previous studies have indicated that AA can induce oxidative stress in renal cells leading to nephropathy. α‑tocopherol exists in numerous types of food, such as nuts, and belongs to the vitamin E isoform family. It possesses antioxidant activities and has been used previously for clinical applications. Therefore, the aim of the present study was to determine whether α‑tocopherol could reduce AA‑induced oxidative stress and renal cell cytotoxicity, determined by cell survival rate, reactive oxygen species detection and apoptotic features. The results indicated that AA markedly induced H2O2 levels and caspase‑3 activity in renal tubular epithelial cells. Notably, the presence of α‑tocopherol inhibited AA‑induced H2O2 and caspase‑3 activity. The present study demonstrated that antioxidant mechanisms of α‑tocopherol may be involved in the increased survival rates from AA‑induced cell injury.

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Vitamin E can improve behavioral tests impairment, cell loss, and dendrite changes in rats’ medial prefrontal cortex induced by acceptable daily dose of aspartame.

Rafati A, Noorafshan A, Jahangir M, Hosseini L, Karbalay-Doust S

Acta Histochem. 2018 Jan;120(1):46-55. doi: 10.1016/j.acthis.2017.11.004. Epub 2017 Nov 21.

Abstract

Aspartame is an artificial sweetener used in about 6000 sugar-free products. Aspartame consumption could be associated with various neurological disorders. This study aimed to evaluate the effect of aspartame onmedial Prefrontal Cortex (mPFC) as well as neuroprotective effects of vitamin E. The rats were divided into seven groups, including distilled water, corn oil, vitamin E (100mg/kg/day), and low (acceptable daily dose) and high doses of aspartame (40 and 200mg/kg/day) respectively, with or without vitamin E consumption, for 8 weeks. Behavioral tests were recorded and the brain was prepared for stereological assessments. Novel objects test and eight-arm radial maze showed impairmentoflong- and short-termmemoriesin aspartame groups. Besides, mPFC volume, infralimbic volume, neurons number, glial cells number, dendrites length per neuron,and number of spines per dendrite length were decreased by 7-61% in the rats treated with aspartame. However, neurons’ number, glial cells number, and rats’ performance in eight-arm radial mazes were improved by concomitant consumption of vitamin E and aspartame. Yet, the mPFC volume and infralimbic cortex were protected only in the rats receiving the low dose of aspartame+vitamin E. On the other hand, dendrites length, spines number,and novel object recognition were not protected by treatment with vitamin E+aspartame. The acceptable daily dose or higher doses of aspartame could induce memory impairments and cortical cells loss in mPFC. However, vitamin E could ameliorate some of these changes.

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The possible protective effects of vitamin E and selenium administration in oxidative stress caused by high doses of glucocorticoid administration in the brain of rats.

Beytut E, Yilmaz S, Aksakal M, Polat S

J Trace Elem Med Biol. 2018 Jan;45:131-135. doi: 10.1016/j.jtemb.2017.10.005. Epub 2017 Oct 16.

Abstract

Acute exposure to high doses of glucocorticoids (GCs) may potentially increase the basal levels of reactive oxygen species (ROS) by altering the defence capacity against oxidative damage. Also, antioxidants may affect the oxidative breakdown of tissues. Therefore, the aim of this work was to determine the effects of dietary intake vitamin E and selenium (Se) on lipid peroxidation (LPO) as thiobarbituric acid reactive substances (TBARS) and on the antioxidative defence mechanisms in the brain of rats treated with high doses of prednisolone. Two hundred and fifty adult male Wistar rats were randomly divided into five groups. The rats were fed a normal diet, but groups 3, 4, and 5 received a daily supplement in their drinking water of 20mg vitamin E, 0.3mg Se, and a combination of vitamin E and Se, respectively, for 30days. For 3days subsequently, the control (group 1) was treated with a placebo, and the remaining 4 groups were injected intramuscularly with 100mg/kg body weight (bw) prednisolone. After the last administration of prednisolone, 10 rats from each group were killed at 4, 8, 12, 24, and 48h and the activities of enzymes selenium-glutathione peroxidase (Se-GSH-Px) and catalase (CAT), and the levels of reduced glutathione (reduced GSH) and TBARS in their brains were measured. Se-GSH-Px and CAT enzyme activities, and reduced GSH levels in the prednisolone treatment group (group 2) began to decrease gradually at 4h (p<0.01, p<0.05, respectively), falling respectively to 60, 50, and 40% of the control levels by 24h (p<0.001, p<0.01), and recovering to the control levels at 48h. In contrast, prednisolone administration caused an increase in the brain TBARS, reaching up to six times the level of the control at 24h (p<0.001). However, supplementation with vitamin E and Se had a preventive effect on the elevation of the brain TBARS and improved the diminished activities of antioxidative enzymes and the levels of reduced GSH. Therefore, the present study attempts to determine the sequence of cellular membrane damage in the brain of the rats after high doses GC administration and the possible roles in vivo of vitamin E and Se, and their combination.

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The effects of vitamin E on brain derived neurotrophic factor, tissues oxidative damage and learning and memory of juvenile hypothyroid rats.

Baghcheghi Y, Beheshti F, Shafei MN, Salmani H, Sadeghnia HR, Soukhtanloo M, Anaeigoudari A, Hosseini M

Metab Brain Dis. 2017 Dec 30. doi: 10.1007/s11011-017-0176-0. [Epub ahead of print]

Abstract

The effects of vitamin E (Vit E) on brain derived neurotrophic factor (BDNF) and brain tissues oxidative damage as well as on learning and memory impairments in juvenile hypothyroid rats were examined. The rats were grouped as: (1) Control; (2) Propylthiouracil (PTU); (3) PTU-Vit E and (4) Vit E. PTU was added to their drinking water (0.05%) during 6 weeks. Vit E (20 mg/kg) was daily injected (IP). Morris water maze (MWM) and passive avoidance (PA) were carried out. The animals were deeply anesthetized and the brain tissues were removed for biochemical measurements. PTU increased the escape latency and traveled path in MWM (P < 0.001). It also shortened the latency to enter the dark compartment of PA as well as the time spent in the target quadrant in probe trial of MWM (P < 0.01-P < 0.001). All the effects of PTU were reversed by Vit E (P < 0.01-P < 0.001). PTU administration attenuated thiol and BDNF content as well as the activities of superoxide dismutase (SOD) and catalase (CAT) in the brain tissues while increased molondialdehyde (MDA). Moreover, Vit E improved BDNF, thiol, SOD and CAT while diminished MDA. The results of the present study showed that Vit E improved BDNF and prevented from brain tissues oxidative damage as well as learning and memory impairments in juvenile hypothyroid rats.

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