Saturday, February 18, 2012

Phytochemicals in Foods - 11 Health Benefits of Tocopherols

Tocopherols are phytochemincals of which many have vitamin E activity, belonging to the group of Lipids, found abundantly in butter, egg yolk, milk fat, some vegetable and seed or nut oils, etc.

Health benefits
1. Antioxidative, anti-inflammatory, and anticarcinogenic activities
In the examination of the inhibition of inflammation as well as of cancer formation and growth in the lung and colon in animal models., using a tocopherol mixture that is rich in gamma-T (gamma-TmT, which contains 57%gamma-T), found that when given in the diet at 0.3%, gamma-TmT inhibited chemically induced lung tumorigenesis in the A/J mice as well as the growth of human lung cancer cell H1299 xenograft tumors. gamma-TmT also decreased the levels of 8-hydroxydeoxyguanosine, gamma-H2AX, and nitrotyrosine in tumors. More evident anti-inflammatory and cancer preventive activities of dietary gamma-TmT were demonstrated in mice treated with azoxymethane and dextran sulfate sodium. These results demonstrate the antioxidative, anti-inflammatory, and anticarcinogenic activities of tocopherols, according to "Inhibition of inflammation and carcinogenesis in the lung and colon by tocopherols" by Yang CS, Lu G, Ju J, Li GX.(1)

2. Cancer prevention
In the study of the cancer-preventive activities of tocopherols and tocotrienols, indicated that a gamma-tocopherol-rich mixture of tocopherols inhibits colon, prostate, mammary and lung tumorigenesis in animal models, suggesting that this mixture may have a high potential for applications in the prevention of human cancer. In this review, we discuss biochemical properties of tocopherols, results of possible cancer-preventive effects in humans and animal models and possible mechanisms involved in the inhibition of carcinogenesis. Based on this information, we propose that a gamma-tocopherol-rich mixture of tocopherols is a very promising cancer-preventive agent and warrants extensive future research, according to "Cancer-preventive activities of tocopherols and tocotrienols" by Ju J, Picinich SC, Yang Z, Zhao Y, Suh N, Kong AN, Yang CS.(2)

3. Bone formation
In the investigation of the antioxidant and anti-inflammatory properties of Alpha- and gamma-tocopherol, the two predominant isomers of vitamin E and their effects on bone metabolism, found that gamma-tocopherol may uncouple bone turnover, resulting in more bone formation than resorption. Vitamin E supplements in the form of alpha-tocopherol suppress serum gamma-tocopherol levels and may have negative effects on bone formation. Further research is needed to investigate the potential anabolic effect of gamma-tocopherol from food sources on bone, according to "Effects of vitamin E on bone turnover markers among US postmenopausal women" by Hamidi MS, Corey PN, Cheung AM.(3)

4. Liver fibrosis
In the study of Antiproliferative and proapoptotic effects of tocopherol and tocol on activated hepatic stellate cells, found that significant cell detachment was also observed in δ-tocopherol- and tocol-treated HSCs. Decreased protein expressions of α-smooth muscle actin and β1 integrin were observed in a dose-dependent manner. These results indicate that δ-tocopherol and tocol induce anoikis in activated HSCs, accordin g to "Antiproliferative and proapoptotic effects of tocopherol and tocol on activated hepatic stellate cells" by Yamaguchi N, Mezaki Y, Miura M, Imai K, Morii M, Hebiguchi T, Yoshikawa K.(4)

5. Antioxidant and Antidiabetic Activities
In the determination of the antioxidant and antidiabetic activities of proximate composition, amino acids, fatty acids, tocopherols, sterols, glucosinolate and phenolic content in extracts, found that all examined extracts were prominently rich in phenolics and glucosinates, and they showed potent antidiabetic and antihemolytic activity. The present study could be helpful in developing medicinal preparations for the treatment of diabetes and related symptoms, according to "Compositional Studies: Antioxidant and Antidiabetic Activities of Capparis decidua (Forsk.) Edgew" by Zia-Ul-Haq M, Cavar S, Qayum M, Imran I, de Feo V.(5)

6. Breast cancer
in the investigation of the breast cancer effect of vitamin E, consisting od eight different variants: α-, β-, γ-, and δ-tocopherols (saturated phytyl tail) and α-, β-, γ-, and δ-tocotrienols (unsaturated phytyl tail), indicated that , γ-tocopherol, and more recently δ-tocopherol, have shown greater ability to reduce inflammation, cell proliferation, and tumor burden. Recent results have shown that γ-enriched mixed tocopherols inhibit the development of mammary hyperplasia and tumorigenesis in animal models, according to "Chemopreventive Activity of Vitamin E in Breast Cancer: A Focus on γ- and δ-Tocopherol" by Smolarek AK, Suh N.(6)

7. Colon cancer
In the investigation of the effects of both alpha and gamma tocopherol on the expression of PPARgamma mRNA and protein in SW 480 colon cancer cell lines and measurement of the intracellular concentrations of vitamin E in SW 480 colon cancer cell lines, found that both alpha and gamma tocopherol can upregulate the expression of PPARgamma which is considered an important molecular target for colon cancer chemoprevention, according to "Gamma (gamma) tocopherol upregulates peroxisome proliferator activated receptor (PPAR) gamma (gamma) expression in SW 480 human colon cancer cell lines" by Campbell SE, Stone WL, Whaley SG, Qui M, Krishnan K.(7)

8. Antioxidant defense
in the study of salmon, a rich source of marine n-3 fatty acids, which may increase oxidative stress and, in turn, and its affect the antioxidant defense system in blood plasma and erythrocytes of pregnant women, found that besides, a concomitant increase in selenium and glutathione concentration as well as glutathione peroxidase and reductase activities were detected as pregnancy progressed. However, tocopherols, retinol, β-carotene, and coenzyme Q(10) decreased in late pregnancy. Collectively, our findings lead to the hypothesis that increased farmed salmon intake may increase antioxidant defenses during pregnancy, according to "Does Consumption of Two Portions of Salmon Per Week Enhance the Antioxidant Defense System in Pregnant Women?" by García-Rodríguez CE, D Mesa M, Olza J, Vlachava M, Kremmyda LS, Diaper ND, Noakes PS, Miles EA, Ramírez-Tortosa MC, Liaset B, Frøyland L, Rossary A, Farges MC, Vasson MP, Aguilera CM, Helmersson-Karlqvist J, Godfrey KM, Calder PC, Basu S, Gil A.(8)

9. The antioxidant and anti-inflammatory activities
In the investigation of the antioxidant and anti-inflammatory actions of tocopherols in mice and determination of whether the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is involved in these activities, indicated that the antioxidant and anti-inflammatory activities of γ-TmT in the colon are mostly due to the direct action of tocopherols in trapping reactive oxygen and nitrogen species, independent of the antioxidant enzymes and anti-inflammatory proteins that are regulated by Nrf2; however, Nrf2 knockout appears to affect the serum levels of tocopherol metabolites, according to "The antioxidant and anti-inflammatory activities of tocopherols are independent of Nrf2 in mice" by Li G, Lee MJ, Liu AB, Yang Z, Lin Y, Shih WJ, Yang CS.(9)

10. Cognitive effects
In the examination of the relation of all plasma vitamin E forms and markers of vitamin E damage (α-tocopherylquinone, 5-nitro-γ-tocopherol) to mild cognitive impairment (MCI) and Alzheimer's disease (AD). Within the AddNeuroMed-Project, plasma tocopherols, tocotrienols, α-tocopherylquinone, and 5-nitro-γ-tocopherol were assessed in 168 AD cases, 166 MCI, and 187 cognitively normal (CN) people, found that compared with cognitively normal subjects, AD and MCI had lower levels of total tocopherols, total tocotrienols, and total vitamin E. In multivariable-polytomous-logistic regression analysis, both MCI and AD cases had 85% lower odds to be in the highest tertile of total tocopherols and total vitamin E, and they were, respectively, 92% and 94% less likely to be in the highest tertile of total tocotrienols than the lowest tertile. Further, both disorders were associated with increased vitamin E damage. Low plasma tocopherols and tocotrienols levels are associated with increased odds of MCI and AD, according to "Tocopherols and tocotrienols plasma levels are associated with cognitive impairment" by Mangialasche F, Xu W, Kivipelto M, Costanzi E, Ercolani S, Pigliautile M, Cecchetti R, Baglioni M, Simmons A, Soininen H, Tsolaki M, Kloszewska I, Vellas B, Lovestone S, Mecocci P; AddNeuroMed Consortium.(10)

11. Renal effects
In the examination of whether γ-tocotrienol (GT3) protects against mitochondrial dysfunction and renal proximal tubular cell (RPTC) injury caused by oxidants, showed that report demonstrating the protective effects of GT3 against RPTC injury by: 1) decreasing production of ROS, 2) improving mitochondrial respiration, coupling, ΔΨ(m), and F₀F₁-ATPase function, 3) maintaining ATP levels, and 4) preventing RPTC lysis. Our data suggest that GT3 is superior to AT in protecting RPTCs against oxidant injury and may prove therapeutically valuable for preventing renal injury associated with oxidative stress, according to "γ-Tocotrienol protects against mitochondrial dysfunction and renal cell death" by Nowak G, Bakajsova D, Hayes C, Hauer-Jensen M, Compadre CM.(11)

12. Etc.


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