Blog Archives

Tocotrienols activate Nrf2 nuclear translocation and increase the antioxidant-related hepatoprotective mechanism in mice liver

Ahmed Atia, Nadia Salem Al-Rawaiq, Azman Abdullah

Curr Pharm Biotechnol . 2020 Sep 27. doi: 10.2174/1389201021666200928095950. Online ahead of print.

Abstract

Background: The most common preparation of tocotrienols is the tocotrienol-rich fraction (TRF). This study aimed to investigate whether TRF induced liver Nrf2 nuclear translocation and influenced the expression of Nrf2-regulated genes.

Methods: In the Nrf2 induction study, mice were divided into control, 2000 mg/kg TRF and diethyl maleate treated groups. After acute treatment, mice were sacrificed at specific time points. Liver nuclear extracts were prepared and Nrf2 nuclear translocation was detected through Western blotting. To determine the effect of increasing doses of TRF on the extent of liver nuclear Nrf2 translocation and its implication on the expression levels of several Nrf2-regulated genes, mice were divided into 5 groups (control, 200, 500 and 1000 mg/kg TRF, and butylated hydroxyanisole-treated groups). After 14 days, mice were sacrificed and liver RNA extracted for qPCR assay.

Results: 2000 mg/kg TRF administration initiated Nrf2 nuclear translocation within 30 min, reached maximum level around 1 h and dropped to half-maximal levels by 24 h. Incremental doses of TRF resulted in dose-dependent increases in liver Nrf2 nuclear levels, along with concomitant dose-dependent increases in the expressions of Nrf2-regulated genes.

Conclusion: TRF activated the liver Nrf2 pathway resulting in increased expression of Nrf2-regulated cytoprotective genes.

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A first description of ataxia with vitamin E deficiency associated with MT-TG gene mutation

Marwa Maalej, Fatma Kammoun, Marwa Kharrat, Wafa Bouchaala, Marwa Ammar, Emna Mkaouar-Rebai, Chahnez Triki, Faiza Fakhfakh

Acta Neurol Belg . 2020 Sep 26. doi: 10.1007/s13760-020-01490-4. Online ahead of print.

Abstract

Ataxia with isolated vitamin E deficiency (AVED) is a rare autosomal recessive cerebellar ataxia disorder that is caused by a mutation in the alpha-tocopherol transfer protein gene TTPA, leading to a lower level of serum vitamin E. Although it is almost clinically similar to Friedreich’s ataxia, its devastating neurological features can be prevented with appropriate treatment. In this study, we present a patient who was initially diagnosed with Friedreich’s ataxia, but was later found to have AVED. Frataxin gene screening revealed the absence of GAA expansion in homozygous or heterozygous state. However, TTPAgene sequencing showed the presence of the c.744delA mutation, leading to a premature stop codon (p.E249fx). In addition, the result of mutational analysis of MT-DNA genes revealed the presence of several variants, including the m.10044A>G mutation in MT-TG gene. Here, we report for the first time the coexistence of both mitochondrial and nuclear genes mutations in AVED.

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Interrelation between Plasma Concentrations of Vitamins C and E along the Trajectory of Ageing in Consideration of Lifestyle and Body Composition: A Longitudinal Study over Two Decades

Alexandra Jungert, Monika Neuhäuser-Berthold

Nutrients . 2020 Sep 25;12(10):E2944. doi: 10.3390/nu12102944.

Abstract

Although the interrelation between vitamins C and E has been demonstrated on an experimental level, its impact on biomarkers in community-dwelling subjects along the trajectory of ageing has not yet been shown. The present longitudinal study investigates the determinants and interrelation of vitamins C and E plasma concentrations in 399 subjects aged ≥60 years with a median follow-up time of 12 years. Linear mixed-effects models were used to analyze the influence of age, sex, body composition, dietary intake, physical activity, smoking and supplement/drug use on plasma vitamin C, plasma α-tocopherol and α-tocopherol/total cholesterol ratio. At baseline, median plasma concentrations of vitamin C and α-tocopherol were 74 and 35 µmol/L. Absolute fat-free mass, physical activity, use of supplements, and plasma α-tocopherol were main determinants of plasma vitamin C in the course of ageing. For the α-tocopherol/total cholesterol ratio, age, use of supplements, use of lipid-modifying drugs, and plasma vitamin C were main determinants. The results reveal a stable positive interrelation between plasma concentrations of vitamins C and E along the trajectory of ageing independent of the other identified determinants. The possible regulatory mechanisms that could explain this robust positive interrelation remain to be elucidated.

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Isotretinoin and α-tocopherol acetate-loaded solid lipid nanoparticle topical gel for the treatment of acne

Shivani Gupta, Sarika Wairkar, Lokesh Kumar Bhatt

J Microencapsul . 2020 Sep 24;1-9. doi: 10.1080/02652048.2020.1823499. Online ahead of print.

Abstract

Aims: This study was aimed to develop Isotretinoin (ITN) and α-tocopherol acetate (α-TA) loaded solid lipid nanoparticle topical gel for better skin sensitivity and potentiation of efficacy.

Methods: ITN and α-TA-loaded solid lipid nanoparticles (AE-SLN) were prepared by microemulsion method with glyceryl mono-stearate as lipid and tween 80: butanol as surfactantmix and characterised. AE-SLN gel was evaluated for physicochemical characteristics, drug release, skin irritation and anti-acne activity in rats.

Results: AE-SLNs had mean particle size of 193.4 nm (zeta-potential -29 mV) and entrapment efficiency of 84%w/w for ITN and 77.4%w/w for α-TA. AE-SLN gel showed sustained drug release for 24 h with a final cumulative release of 95.8% w/w and 89.1%w/w for ITN and α-TA. AE-SLN gel showed no erythema or edoema in rabbits and potent efficacy in rat model of acne.

Conclusion: In conclusion, AE-SLN gel has the potential to use as a non-irritant topical formulation for the treatment of acne.

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Effects of vitamin E in a glucocorticoid induced cataract model in chicken embryo

A Vurmaz, A Ertekin, M Cem Sabaner, E Atay, E Bozkurt, A Bilir

Biotech Histochem . 2020 Sep 22;1-8. doi: 10.1080/10520295.2020.1818284. Online ahead of print.

Abstract

We investigated the antioxidant effects of vitamin E on a glucocorticoid (GC) induced model of cataracts in chick embryos. We used 70 fertilized eggs divided into seven groups as follows: phosphate-buffered saline (PBS) group, olive oil treatment (OO) group, hydrocortisone treatment (HC) group, olive oil and hydrocortisone treatment (OO + HC) group, 50 mg/kg vitamin E and hydrocortisone treatment (HC + VE (50)) group, 25 mg/kg vitamin E and hydrocortisone treatment (HC + VE (25)) group and 15 mg/kg vitamin E and hydrocortisone treatment (HC + VE (15)) group. On day 17, chick embryos were removed from the eggs and lens and liver tissues were excised. Cataract formation was evaluated and total antioxidant status (TAS), total oxidant status (TOS), malondialdehyde (MDA) and glutathione peroxidase (GPx) were measured in lens and liver tissues; MDA was measured only in liver. The lenses in the HC + VE (50) group exhibited significantly higher levels of GPx and TAS, and lower levels of TOS than for HC and OO + HC groups. The livers of the HC + VE (50) group exhibited significantly higher levels of GPx and lower levels of MDA than for the HC and OO + HC groups. The HC + VE (50) group lenses were evaluated as grade 1, because the nuclei were completely free of cataracts, likely due to the antioxidative effect of high dose VE. VE is an effective antioxidant agent that exhibits a dose-response effect, for ameliorating the negative effects of GCs.

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Vitamin E Deficiency Tied to Abnormal Nervous System Development in Model Organism

In research that could have key ramifications for women of childbearing age, the findings of a study by Oregon State University scientists have shown that embryos produced by vitamin E-deficient zebrafish have malformed brains and nervous systems. “This is totally amazing—the brain is absolutely physically distorted by not having enough vitamin E,” said research lead Maret Traber, PhD, a professor in the OSU College of Public Health and Human Sciences, and the Ava Helen Pauling Professor at Oregon State’s Linus Pauling Institute. Traber, and colleagues have published their findings in Scientific Reports, in a paper titled, “Vitamin E is necessary for zebrafish nervous system development.”

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Eczema treatment: Natural vitamin to help ease painful rash-like symptoms

Eczema is a long-term condition that causes the skin to become dry, itchy, red and cracked, according to the national health body. There are a variety of creams and treatments on the market all claiming to be the holy grail in helping to combat rash-like symptoms. According to studies, vitamin E could be the answer in helping to temporarily ease this painful skin condition.

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Vitamin E needed for proper nervous system development

In research with key ramifications for women of childbearing age, findings by Oregon State University scientists show that embryos produced by vitamin E-deficient zebrafish have malformed brains and nervous systems.

“This is totally amazing — the brain is absolutely physically distorted by not having enough vitamin E,” said Maret Traber, a professor in the OSU College of Public Health and Human Sciences.

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A Mechanical Mechanism for Vitamin E Acetate in E-cigarette/Vaping-Associated Lung Injury

Mitchell DiPasquale, Omotayo Gbadamosi, Michael H L Nguyen, Stuart R Castillo, Brett W Rickeard, Elizabeth G Kelley, Michihiro Nagao, Drew Marquardt

Chem Res Toxicol . 2020 Sep 21;33(9):2432-2440. doi: 10.1021/acs.chemrestox.0c00212. Epub 2020 Sep 4.

Abstract

The outbreak of electronic-cigarette/vaping-associated lung injury (EVALI) has made thousands ill. This lung injury has been attributed to a physical interaction between toxicants from the vaping solution and the pulmonary surfactant. In particular, studies have implicated vitamin E acetate as a potential instigator of EVALI. Pulmonary surfactant is vital to proper respiration through the mechanical processes of adsorption and interface stability to achieve and maintain low surface tension at the air-liquid interface. Using neutron spin echo spectroscopy, we investigate the impact of vitamin E acetate on the mechanical properties of two lipid-only pulmonary surfactant mimics: pure 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and a more comprehensive lipid mixture. It was found that increasing vitamin E acetate concentration nonlinearly increased membrane fluidity and area compressibility to a plateau. Softer membranes would promote adsorption to the air-liquid interface during inspiration as well as collapse from the interface during expiration. These findings indicate the potential for the failure of the pulmonary surfactant upon expiration, attributed to monolayer collapse. This collapse could contribute to the observed EVALI signs and symptoms, including shortness of breath and pneumonitis.

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