A review on vitamin E natural analogues and on the design of synthetic vitamin E derivatives as cytoprotective agents.

Author(s):  
Panagiotis Theodosis-Nobelos ◽  
Georgios Papagiouvannis ◽  
Eleni A. Rekka

: Vitamin E, essential for human health, is widely used worldwide for therapeutic or dietary reasons. The differences in the metabolism and excretion of the multiple vitamin E forms are presented in this review. The important steps that influence the kinetics of each form and the distribution and processing of vitamin E forms by the liver are considered. The antioxidant as well as non-antioxidant properties of vitamin E forms are discussed. Finally, synthetic tocopherol and trolox derivatives, based on the design of multitarget directed compounds, are reviewed. It is demonstrated that selected derivatization of vitamin E or trolox structures can produce improved antioxidants, agents against cancer, cardiovascular and neurodegenerative disorders.

2020 ◽  
pp. 088532822097735
Author(s):  
Fedra P Zaribaf ◽  
Harinderjit S Gill ◽  
Elise C Pegg

Ultra-high molecular weight polyethylene (UHMWPE) can be made radiopaque for medical imaging applications through the diffusion of an iodised oil-based contrast agent (Lipiodol Ultra Fluid). A similar process is used for Vitamin E incorporated polyethylene which provides antioxidant properties. This study aimed to investigate the critical long-term properties of oil-infused medical polyethylene after 4 weeks of accelerated thermal ageing. Samples treated with an oil (Vitamin E or Lipiodol) had a higher oxidation stability than currently used medical grade polyethylene, indicated by a smaller increase in oxidation index after ageing (Vitamin E + 36%, Lipiodol +40%, Untreated +136%, Thermally treated +164%). The tensile properties of oil treated polyethylene after ageing were significantly higher than the Untreated and Thermally treated controls (p<0.05) indicating less mechanical degradation. There was also no alteration in the percentage crystallinity of oil treated samples after ageing, though the radiopacity of the Lipiodol treated samples reduced by 54% after ageing. The leaching of oil with time was also investigated; the leaching of Lipiodol and Vitamin E followed the same trend and reached a steady state by two weeks. Overall, it can be concluded that the diffusion of an oil-based fluid into polyethylene not only increases the oxidative and chemical stability of polyethylene but also adds additional functionality (e.g. radiopacity) providing a more suitable material for long–term medical applications.


2016 ◽  
Vol 56 (8) ◽  
pp. 1285 ◽  
Author(s):  
S. S. Chauhan ◽  
F. Liu ◽  
B. J. Leury ◽  
J. J. Cottrell ◽  
P. Celi ◽  
...  

Selenium (Se) and vitamin E are essential micronutrients for animal health and production. The major function of both Se and vitamin E is to prevent the oxidative damage of biological membranes and they can influence growth, reproduction, immune function, health, and product quality in ruminants. Both Se and vitamin E are important for maintaining low cellular and systemic concentrations of reactive oxygen species and lipid hydroperoxides, to ensure optimum cellular function. Discovery of various selenoproteins and vitamin E-responsive genes has contributed significantly to improving our understanding about multiple functions of Se and vitamin E. There is evidence that these functions extend beyond the classical antioxidant properties to immunomodulation and intracellular cell signalling and gene regulation. Research in recent years has also shown that supranutritional supplementation of Se and vitamin E is required to improve the performance of ruminants under certain stressful conditions such as heat stress and during transition period. Considering the growing awareness among consumers of the benefits of antioxidant-rich food, there is a great opportunity for the livestock industries to focus on producing antioxidant-enriched milk and meat products or functional foods. The present review focuses on the recent developments in understanding multiple functions of Se and vitamin E at the cellular and molecular level and the effects of supranutritional supplementation on ruminant performance. In addition, the paper also articulates the potential opportunities to produce functional foods enriched with antioxidants, and underlines the need for optimum supplementation of these micronutrients for efficient ruminant production.


2002 ◽  
Vol 61 (2) ◽  
pp. 191-202 ◽  
Author(s):  
Michael Grundman ◽  
Patrick Delaney

Oxidative damage is present within the brains of patients with Alzheimer's disease (AD), and is observed within every class of biomolecule, including nucleic acids, proteins, lipids and carbohydrates. Oxidative injury may develop secondary to excessive oxidative stress resulting from β-amyloid-induced free radicals, mitochondrial abnormalities, inadequate energy supply, inflammation or altered antioxidant defences. Treatment with antioxidants is a promising approach for slowing disease progression to the extent that oxidative damage may be responsible for the cognitive and functional decline observed in AD. Although not a uniformly consistent observation, a number of epidemiological studies have found a link between antioxidant intake and a reduced incidence of dementia, AD and cognitive decline in elderly populations. In AD clinical trials molecules with antioxidant properties such as vitamin E andGinkgo bilobaextract have shown modest benefit. A clinical trial with vitamin E is currently ongoing to determine if it can delay progression to AD in individuals with mild cognitive impairment. Combinations of antioxidants might be of even greater potential benefit for AD, especially if the agents worked in different cellular compartments or had complementary activity (e.g. vitamins E, C and ubiquinone). Naturally-occurring compounds with antioxidant capacity are available and widely marketed (e.g. vitamin C, ubiquinone, lipoic acid, β-carotene, creatine, melatonin, curcumin) and synthetic compounds are under development by industry. Nevertheless, the clinical value of these agents for AD prevention and treatment is ambiguous, and will remain so until properly designed human trials have been performed.


1996 ◽  
Vol 1996 ◽  
pp. 30-30
Author(s):  
C.O. Leskanich ◽  
K.R. Matthews ◽  
C.C. Warkup ◽  
R.C. Noble

The tissues of animals for food use have come to be associated with a predominance of saturated and monounsaturated fatty acids, the result of which has been to contribute to the perceived human dietary imbalance of fatty acids. The fact that porcine tissues assume a fatty acid composition similar to that of the respective diet has enabled the composition to be altered with respect to human dietary needs (Morgan et al, 1992). The fatty acid compositions of rapeseed and fish oils are characterised by a number of factors of relevance to human health recommendations (BNF, 1992). Thus, rapeseed oil contains a low content of saturates, a moderate content of linoleic acid and a high content of α-linolenic acid whilst fish oil contains high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Although benefiting the nutritional value of meat/fat, the feeding of increased levels of highly polyunsaturated fatty acids has the potential, in theory at least, of adversely affecting organoleptic and various physical properties. Such adverse effects could be manifested during and/or after the preparation and cooking of the meat or meat products at which times the oxidative degradation of fatty acids is maximised. The inclusion of dietary vitamin E has a range of beneficial effects on meat quality principally due to its antioxidant effects. The present experiment was an attempt to optimise the fatty acid composition of pork and pork products for human health purposes whilst not adversely affecting factors controlling consumer acceptability.


2012 ◽  
Vol 56 (7) ◽  
pp. 1131-1147 ◽  
Author(s):  
Guillermo Rodríguez-Gutiérrez ◽  
Garry G. Duthie ◽  
Sharon Wood ◽  
Phil Morrice ◽  
Fergus Nicol ◽  
...  

2018 ◽  
pp. e12733 ◽  
Author(s):  
Emad Karrar ◽  
Sujitraj Sheth ◽  
Willard Burton Navicha ◽  
Wei Wei ◽  
Hinawi Hassanin ◽  
...  

Author(s):  
L. P. Nilova ◽  
S. M. Malyutenkova

The results of studies of the biochemical composition and antioxidant properties of nuts sold in the consumer market of St. Petersburg were presented in the work. The objects of research were kernels of nuts: sweet almonds, hazelnuts, cashews, walnuts. Total Soxhlet lipids, fatty acid composition, vitamin E, fractional composition of tocopherols and phytosterols, total phenolic compounds and flavonoids, antioxidant activity by FRAP with ferric chloride, o-phenanthroline and Triton X 100 were determined in nuts. Nuts varied in lipid content (42.6–65.4%) with a predominance of unsaturated fatty acids from 80.4 to 92.4 relative%. Oleic acid prevailed in the fatty acids of almonds, hazelnuts and cashews, while linoleic acid prevailed in walnuts. Walnuts contained the highest amount of polyunsaturated fatty acids. The antioxidant properties of nuts were formed by a complex of water and fat-soluble antioxidants. Fat-soluble antioxidants included vitamin E with a predominance of ?-tocopherol in the kernels of sweet almonds and hazelnuts, ?-tocopherol - in walnuts and cashews. Only sweet almond kernels contained all the tocopherol fractions. ?- and ?-tocopherols were absent in hazelnut lipids, while ?-tocopherols were absent in cashews and walnuts. ?-sitosterol, campesterol and stigmasterol with a predominance of ?-sitosterol were identified in the composition of phytosterols in all nut kernels. Water-soluble antioxidants are mainly represented by phenolic compounds, the amount of which varies widely depending on the type of nuts: cashews


1999 ◽  
Vol 69 (2) ◽  
pp. 92-95 ◽  
Author(s):  
Chopra ◽  
Bhagavan

There are several reports in the literature on the relative bioavailabilities of RRR (natural) vs. all-rac (synthetic) forms of vitamin E in humans and animal models but none on the bioavailability of alpha-tocopherol in mixed vitamin E formulations. In the present study we examined the bioavailability of alpha-tocopherol in a typical commercially available product containing mixed tocopherols. We also tested a formulation containing all-rac-alpha-tocopherol with mixed tocopherols for purposes of comparison along with straight RRR-and all-rac-alpha-tocopheryl acetate as reference products. Normal male subjects were given one of the four formulations of vitamin E (800 IU per day in softgel capsule form for 10 days): 1. All-rac-alpha-tocopheryl acetate, 2. RRR-alpha-tocopheryl acetate, 3. RRR-alpha-tocopherol with mixed tocopherols, and 4. all-rac-alpha-tocopherol with mixed tocopherols. Both serum alpha- and gamma-tocopherols were determined by HPLC at baseline, and at days 2, 4, 7 and 10. The values for alpha- at baseline and 10 days were 0.80, 0.80, 0.80 & 0.79 mg/dl and 1.67, 1.72, 1.76 & 1.62 mg/dl. The values for gamma- were 0.28, 0.29, 0.30 & 0.29 mg/dl and 0.11, 0.08, 0.10 & 0.10 mg/dl. Thus the data show that a) the bioavailability of RRR-and all-rac-alpha-tocopherols is not affected by other tocopherols, and b) both RRR-and all-rac-alpha-tocopherol (free or esterified) significantly suppress the serum gamma tocopherol to the same extent. Furthermore, since there was no difference in the serum values of alpha-tocopherol between RRR-and all-rac-vitamin E given the same dose as IUs, the data also support the currently accepted ratio of 1.36 for the biopotency of RRR- vs. all-rac-alpha-tocopheryl acetate.


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