• Journal of Nutrition and Health
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• v.43 no.3
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• pp.304-314
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• 2010

Vitamin E has been a generic term for all tocopherol and tocotrienol derivatives. The most active form of vitamin E isoforms in vivo is regarded to be $\alpha$-tocopherol which is the only form defined as vitamin E in the US Food and Nutrition Board, causing controversy over setting dietary reference intake (DRI) of vitamin E. However, most of the countries other than the US maintain the original concept that all isoforms are accepted as vitamin E but with different biopotency. The roles of the isoforms of vitamin E other than $\alpha$-tocopherol have received continuous attention. Among them those of $\gamma$-tocopherol and $\alpha$-tocotrienol have been most studied in comparison with $\alpha$-tocopherol, since $\gamma$-tocopherol comprises major form of vitamin E in many plant seeds and those of the both vitamin E have been implicated in unique physiological functions. This review summarizes findings that have led a better understanding of vitamin E absorption, transport, tissue storage and various functions common and specific to vitamin E isoforms focusing $\alpha$- and $\gamma$-tocopherol as well as tocotrienols. It is expected to help redefining vitamin E and setting its DRI for Koreans.

• Nutritional Sciences
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• v.6 no.1
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• pp.20-24
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• 2003

The effect of a-tocopherol on the formation and accumulation of phospholipid hydroperoxides, especially of phosphatidylcholine hydroperoxides, in the tissues of 2, 2 -azobis Hydrochloride (AAPH) - dosed rats was investigated. In a-tocopherol supplemented rats, the activities of glutathione peroxidase, catalase and superoxide dismutase were significantly inhibited, compared with the AAPH group. AAPH treatment led to oxidation of phospholipids in the liver, lungs, brain, plasma and red blood cells (RBC), resulting in a notable increase in phosphatidylcholine hydroperoxide (PCOOH). All tissues of the rats given an $\alpha$-tocopherol supplement showed an attenuation of the stimulating effect of AAPH, leading to low levels of formation of PCOOH. Also, the rats injected with AAPH and a-tocopherol showed relatively normal-appearing hepatocytes, except for a little loss of the granules. With regards to the morphological appearance of the liver, it was observed that oral intakes of a -tocopherol resulted in an antioxidant defense against attacks of peroxyl radicals. Thus, we suggest that a-tocopherol is potentially helpful in protecting membrane phospholipids against oxidative damage in vivo.

• Nutrition Research and Practice
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• v.9 no.2
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• pp.192-198
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• 2015

BACKGROUND/OBJECTIVES: Vitamin E is a fat-soluble vitamin and functions primarily as a lipid antioxidant. Inadequate vitamin E status may increase risk of several chronic diseases. Thus, the objectives of this study were to estimate intake and plasma concentration of each tocopherol and to evaluate vitamin E status of Korean adults. SUBJECTS/METHODS: Three consecutive 24-h food recalls and fasting blood samples were collected from healthy 20- to 59-y-old adults (33 males and 73 females) living in the Seoul metropolitan area, South Korea. ${\alpha}$-, ${\beta}$-, ${\delta}$-, and ${\gamma}$-tocopherol intakes and plasma concentrations of tocopherols (${\alpha}$-, ${\delta}$-, and ${\gamma}$- tocopherol) were analyzed by gender. RESULTS: Dietary vitamin E and total vitamin E intake (dietary plus supplemental vitamin E) was $17.68{\pm}14.34$ and $19.55{\pm}15.78mg$ ${\alpha}$-tocopherol equivalents, respectively. The mean daily ${\alpha}$-tocopherol, and ${\gamma}$-tocopherol intakes were $3.07{\pm}2.27mg$ and $5.98{\pm}3.74mg$, respectively. Intakes of total vitamin E and each tocopherol of males were significantly higher than those of females (P < 0.05). Plasma ${\alpha}$-tocopherol concentration was $15.45{\pm}10.16$ of males and $15.00{\pm}4.54{\mu}mol/L$ of females, respectively. There were no significant differences in plasma tocopherol concentrations by gender ($P{\geq}0.05$). Plasma ${\alpha}$-tocopherol was negatively correlated with ${\gamma}$-tocopherol intake (P < 0.05). Twenty-three percent of the subjects had plasma ${\alpha}$-tocopherol concentrations < $12{\mu}mol/L$ indicating a biochemical deficiency of vitamin E. Approximately 8% and 9% of these participants had plasma ${\alpha}$-tocopherol:total lipid ratio less than $1.59{\mu}mol/mmol$ and plasma ${\alpha}$-tocopherol:total cholesterol ratio less than $2.22{\mu}mol/mmol$, respectively, which are also indicative of vitamin E deficiency. CONCLUSIONS: Vitamin E intakes of Korean adults were generally adequate with the Korean Dietary Reference Intakes for vitamin E. However, ${\alpha}$-tocopherol intake was lower than that reported in other countries, and 23% of the subjects in the current study were vitamin E deficient based on plasma ${\alpha}$-tocopherol concentrations.

• Korean Journal of Poultry Science
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• v.38 no.2
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• pp.129-136
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• 2011

The objective of this study was to evaluate the effects of different levels of ${\alpha}$-tocopherol and selenium in broiler diets on performance and physicochemical properties of chicken thigh meat. A total of 360 broiler chicks divided into six groups were fed a basal diet (control) or basal diet supplemented with 50 IU ${\alpha}$-tocopherol/kg (T1), 100 IU ${\alpha}$-tocopherol/kg (T2), 200IU ${\alpha}$-tocopherol/kg (T3), 0.3 ppm selenium/kg (T4), and 100 IU ${\alpha}$-tocopherol/kg + 0.3 ppm selenium/kg (T5) for five weeks. Growth performance and proximate composition of chicken thigh meat were not influenced by all dietary treatments, except for crude fat, which was significantly lower in the treatment with ${\alpha}$-tocopherol or selenium, or both compared to control. The dietary ${\alpha}$-tocopherol and selenium supplementation had no significant effects on pH, CIE $L^*$ (lightness), and $b^*$ (yellowness) values but TBARS (thiobarbituric acid reactive substance) values were decreased (P<0.05) by the addition of ${\alpha}$-tocopherol and selenium. CIE $a^*$ (redness) values increased significantly with added ${\alpha}$-tocopherol and selenium relative to the control (P<0.05). Likewise, changes in fatty acid composition in chicken thigh meat with the dietary supplementations with ${\alpha}$-tocopherol, selenium and their combination significantly increased (P<0.05) unsaturated fatty acid, whereas saturated fatty acid were decreased. It was concluded that the addition of 200 IU ${\alpha}$-tocopherol (T3) and 100 IU of ${\alpha}$-tocopherol plus 0.3 ppm selenium (T5) were most effectiveness in the improvements in the lipid oxidative stability of chicken meat when compared to the control.

• Nutritional Sciences
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• v.9 no.4
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• pp.323-329
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• 2006

To more accurately estimate vitamin A and vitamin E intake of Koreans, food composition databases of the tocopherol and carotenoid contents of Korean foods are needed. In this study, the tocopherol $(\alpha-,\;\gamma-,\;and\;\delta-)$ and carotenoid ($\alpha-carotene,\;\beta-carotene,\;\beta-ctyptoxanthin$, lutein, and zeaxanthin) contents of 12 Korean cooked combination foods commonly consumed by children in Kwangju, Republic of Korea, were determined using reversed-phase HPLC. All samples were obtained from 3 different households in Kwangju during summer, 2005. All cooked foods in this study had detectable quantities of $\alpha-tocopherol,\;\gamma-tocopherol$ except for shoegogimugook, and $\delta-tocopherol$ except for myulchibokkeum Doejigogibokkeum had the highest $\alpha-tocopherol$ content (0.64 mg/l00 g edible portion), and $\gamma-tocopherol\;and\;\delta-tocopherol$ contents of gimbab were the highest among the foods (1.01 and 0.26 mg/l00 g edible portion). $\beta-carotene$ was found in all food samples. Gimbab had the highest contents of $\alpha-carotene,\;\beta-carotene$, and lutein among Korean cooked combination foods (158.3, 266.6, and $375.4{\mu}g/100g$ edible portion). Miyukgook contained only $\beta-carotene$ ($2.5{\mu}g/100g$ edible portion). Considerable sample-to-sample variability in tocopherol and carotenoid compositions were observed in several Korean cooked combination foods included in this study. Some of these carotenoids $(\alpha-carotene,\;\beta-carotene,\;and\;\beta-cryptoxanthin)$ are vitamin A precursors. The findings of this study may be valuable for use in Korean databases as well as nutrient consumption research for vitamin A and vitamin E.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.347-352
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• 2003

In order to compare quality characteristics and oxidative stabilities of rice germs prepared under different roasting conditions, sensory evaluation, color value, tocols (tocopherol+tocotrienol) contents, and peroxide value were investigated. Optimum roasting temperatures for the best acceptability were 20, 10, and 6 min at 170, 180 and 190, respectively. Hunter color a values of rice germ increased as roasting temperature and time increased, whereas L value decreased. Peroxide values of unroasted, and roasted rice germs at $170^{\circ}C$ for 20 min, $180^{\circ}C$ for 10 min, and $190^{\circ}C$ for 6 min were 2.0, and 145.6, 169.5, and 182.9 meq/kg, respectively, after 9 days storage at $60^{\circ}C$. Four tocopherol and three tocotrienol isomers were identified, whereas no ${\beta}$-tocotrienol was detected. The major tocopherol and tocotrienol isomers in rice germ were ${\alpha}$-tocopherol and ${\alpha}$-tocotrienol, respectively. ${\alpha}$-Tocopherol content in roasted rice germ decreased significantly during storage, whereas those of ${\beta}$- and ${\gamma}$-tocopherols slowly decreased. ${\delta}$-Tocopherol had the highest stability among tocopherol isomers in roasted rice germ. Similar trends were observed in tocotrienol isomers.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.64-68
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• 1990

The stabilization effect of .alpha.-tocopherol incorporated into liposomal phospholipid membrane was investigated by fluorospectrophotometry and UV-visible spectretarded by the presence of .alpha.-tocopherol in the bilayer of liposomal phospholipid membrane relative to cholesterol-containing liposomes and pure phospholipid liposomes. .alpha.-tocopherol-containing liposomes prolonged the oxidation of liposomes-embedded heme as those of cholesterol-containing liposomes and pure phospholipid liposomes. Thus .alpha.-tocopherol-containing liposomes may be useful for the carrier systems of nutrients and drugs to phospholipid bilayer and stabilized liposomes.

• Korean journal of food and cookery science
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• v.27 no.6
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• pp.713-721
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• 2011

Korean cabbage (Brassica campestris L.ssp.pekinensis) is one of the major cruciferous vegetables. Cruciferous vegetables contain a rare series of secondary metabolites of amino acids called glucosinolates, as well as carotenoids, tocopherol, vitamin C and fibers. This study evaluated the effect of common cooking methods (boiling, microwaving, steaming and frying) on the phytochemical content (lutein, ${\beta}$-carotene, ${\gamma}$-tocopherol, and ${\alpha}$-tocopherol), and total antioxidant capacity of Korean cabbages, determined by DPPH assay and ABTS assay. Boiling caused a decrease in carotenoids, lutein and tocopherols. Microwaving and steaming were relatively good cooking methods for maintaining lutein, ${\beta}$-carotene, ${\gamma}$-tocopherol, and ${\alpha}$-tocopherol. The overall results of this study demonstrate that some domestic cooking procedures, specifically microwave and steaming, increased the bioaccessibility of carotenoids and tocopherol, highlighting the positive role of the nutritional properties of Korean cabbage.

• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.48-55
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• 1998

An acute ethanol load(50mmol/kg , i.p) resulted in an increase in peroxidation and a decrease in the levels of $\alpha$-tocopherol and ascorbate in rat cerebellum. Pretreatement with allopurinol(146$\mu$mol/kg, i.p) prevented the ethnol-induced increment in lipid peroxidation and decrease in $\alpha$-tocopherol content. However, the decrease of ascorbate was of greater magnitude when allopurinol was associated with ethanol. These results suggested that allopurinol. besides its action as a radical scavenger and xanthine oxidase inhibitor, might favor the regeneration of $\alpha$-tocopherol antioxidant acitviity was studied using ${\gamma}$-radiolysis in aerated ethanolic solutions. Even though allopurinol did not react by itself with $\alpha$-hydroxyethyl-peroxyl radicals [H3C-CH(OH)OO] , it enhance the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$tocopherol. The regeneration of $\alpha$-tocopherol from the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$-tocophero. The regeneration of $\alpha$-tocopherol from the $\alpha$-tocopherol radical by ascorbate remained as efficient in the presence of allopurinol as in its absence. The effects of allopurinol on the Vitamin E oxidation-reduction mechanism could be involoved in the beneficial effectof allopurinol on the biological cellular damages linked to free radical reactions.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.497-504
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• 2000

To document that effects of hyperbaric oxygen(HBO) and ${\alpha}-tocopherol$ on full-thickness skin grafts in rat, we performed full-thickness skin grafts bilaterally on each rats. The HBO-treated rats were received HBO twice daily for 90 minutes at 2 ATA. Surgical control rats were not treated with HBO. ${\alpha}-tocopherol$ treated rats were received the agent via oral gastric tube daily for 3 days preoperative and a fourth dose 1 to 2 hours postoperative. HBO plus ${\alpha}-tocopherol$ treated rats were received HBO and ${\alpha}-tocopherol$ as mentioned above. Biopsy specimens were taken from each rat at the time of grafting and on days 2, 4, 7, 10, 14, 21, and 28, then were processed for tissue-concentration of total glutathione(GSHt), oxidized/reduced glutathione level, and thiobarbituric acid-reactive substance(TBARS) levels. The percentage of viable graft on day 10 ranged from 67 to 93%, and was not significantly different among the each other groups. The percentage of viable graft were, however, higher in HBO plus ${\alpha}-tocopherol$ treated rats(78.6%) than in HBO alone treated rats(59.1%), ${\alpha}-tocopherol$ alone treated rats(66.7%) and surgical control rats(58.2%). TBARS concentration had a significant increase from preoperative concentration at day 2, and peak concentration at day 4(p<0.01). Concentration then decreased to preoperative concentration at day 28. GSHt concentration of free skin graft had a similar patteren of change in four groups and decreased significantly from preoperative concentration at day 2, returning to preoperative concentration by day 7(surgical control, HBO-treated, and ${\alpha}-tocopherol-treated$, alone) and 28(HBO plus ${\alpha}-tocopherol-treated$). Percentage of the concentration of reduced glutathione decreased in surgical control, HBO-treated and, ${\alpha}-tocopherol-treated$(p<0.05), and HBO plus ${\alpha}-tocopherol-treared$(p<0.01) on day 7 after surgery, whereas the concentration of oxidized increased significantly in HBO-treated(p<0.05), ${\alpha}-tocopherol-treated$(p<0.05), and HBO plus ${\alpha}-tocopherol-treated$(p<0.01).