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Life Extension Magazine

LE Magazine June 2001

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The cancer studies

imageWhile vitamin E’s ability to inhibit cancer growth such as pancreas, breast and prostate has been shown by in vitro studies, now researchers at the University of California (UCLA) have found that the micronutrient may also serve a purpose in warding off gastric cancer too. An in vitro study looked at the effects of treating gastric cancer cells with doses of 25, 50 or 100 micrograms/milliliter of vitamin E. When researchers analysed the outcome after 24, 48 and 72 hours of incubating the treated malignant cells, they found that all three doses of vitamin E worked equally well at 72 hours to inhibit tumor growth, but that the 50 and 100 microgram/milliliter doses worked better at all time points. The authors concluded from their results that vitamin E effectively inhibits gastric carcinoma cell growth in vitro in a dose- and time-dependent manner.(35)

But vitamin E is not only proving effective at inhibiting cancer cell growth,(29) as it has also been shown to be among the antioxidant agents that can enhance the efficacy of chemotherapeutic agents, as well as decrease the side effects related to their cytotoxicity. For example, consider a recent study that looked at how vitamin E might assist in increasing the susceptibility of colon carcinoma cells to the chemotherapeutic agent, 5-fluorouracil (5 FU). Vitamin E, in conjunction with N-acetylcysteine (NAC), reduced intercellular oxidant levels by 500%, which increased pro-apoptotic bax protein expression and apoptotic response to a non-toxic dose of 5 FU in two colorectal cancer cell lines (colo 201 and colo 205).(36) Meanwhile, in another study, vitamin E was shown to oppose the toxic effects of the chemotherapeutic agent doxorubicin in the skin (as evidenced by increased theoredoxin reductase activity in skin, as well as increased glutathione peroxidase activity in the erethrocytes) and may therefore also alleviate cytotoxicity associated with chemotherapy treatment.(37)

HOW MUCH GAMMA-TOCOPHEROL?

Scientists suggest that those who take alpha-tocopherol vitamin E supplements should also supplement with at least 20% gamma-tocopherol. In response to these recom-mendations, Foundation members have been taking one capsule a day of a supplement called Gamma E Tocopherol that provides 210 mg of gamma-tocopherol in each capsule. This same amount of gamma-tocopherol (210 mg) is also included in the Life Extension Booster formula. Foundation members obtain additional protection in the Super CoQ10 softgel caps that are fortified with a tocotrienol complex that provides the gamma tocotrienol vitamin E fraction.

Since the average member takes between 400 IU and 1000 IU a day of alpha-tocopherol vitamin E , the 210 mg of gamma-tocopherol found in either Gamma E Tocopherol or Life Extension Booster more than fulfills this 20% gamma-tocopherol requirement.

Fertility

Apart from heart disease and cancer, vitamin E has also been recognized in terms of its ability to improve sperm function and promote healthy pregnancy, although this role was demonstrated several decades ago. In Japan, researchers demonstrated that vitamin E protects trophoblastic cells (these mediate fetal implantation and form a thin membrane to cover the fetus) against oxidative stress in the labyrinthine region of the placenta during its development.(25) Alpha-tocopherol transfer protein (alpha-TTP) is known to bind alpha-tocopherol and is associated with vitamin E deficiency, as has been shown in patients with ataxia. In essence, the alpha-tocopherol transfer gene expression modulates circulating levels of alpha-tocopherol. The researchers examined the effect of the protein in male mice fertility and in pregnant female mice, finding that alpha-tocopherol transfer protein did not affect male fertility, its expression related to severe impairment of the placentas that culminated in the death of the embryos at mid-gestation. Investigators then tried to administer excess vitamin E or a synthetic antioxidant supplement to pregnant female mice. In this case, results showed that the extra vitamin E, or antioxidant supplementation, prevented placental failure and allowed the mice to reach full-term. Other findings suggest that vitamin E also helps to protect sperm from oxidative insult that would tamper with its structural integrity and normal functioning.(23) Such findings trace back to vitamin E’s humble beginnings, before any relation to heart disease and cancer was made. Keep in mind that vitamin E was discovered in the 1920s after it was found that rats fed a vitamin E deficient diet could not reproduce. The term tocopherol now used to identify vitamin E comes from the Greek word meaning “to bear offspring.” Of course, as we are finding out, that name does not appropriately encompass the multi-faceted role that vitamin E is proving to play in overall health.

Conclusion

What the JAMA report helped confirm is the fact that taking a high dose of a single antioxidant may not be an effective way to prevent lipid peroxidation. Since most serious supplement consumers take vitamin C and CoQ10 along with their vitamin E, the results of this study would not appear to pertain to them. Those who take the gamma-tocopherol form of vitamin E should be especially comforted to know that they may be obtaining optimal protection against a wide range of toxic free radicals that induce lipid peroxidation.

References

1. Meagher, E. A., et al. Effects of Vitamin E on Lipid Peroxidation in Healthy Persons JAMA 2001 Mar 7; 285(9):1178-82.

2. Mawatari S, et al. Effects of ascorbic acid on peroxidation of human erythrocyte membranes by lipoxygenase. J Nutr Sci Vitaminol (Tokyo) 1999 Dec;45(6):687-99.

3. Stoyanovsky DA, et al. Endogenous ascorbate regenerates vitamin E in the retina directly and in combination with exogenous dihydrolipoic acid. Curr Eye Res 1995 Mar;14(3):181-9.

4. Chan AC. Partners in defense, vitamin E and vitamin C. Can J Physiol Pharmacol 1993 Sep;71(9):725-31.

5. Niki E. Interaction of ascorbate and alpha-tocopherol. Ann N Y Acad Sci 1987;498:186-99.

6. Scarpa M, et al. Formation of alpha-tocopherol radical and recycling of alpha-tocopherol by ascorbate during peroxidation of phosphatidylcholine liposomes. An electron paramagnetic resonance study. Biochim Biophys Acta 1984 Sep 28;801(2):215-9.

7. Vitamin E may protect against prostate cancer, December 19, 2000, Reuters Health. December 19, 2000.

8. Christen S, et al. gamma-tocopherol traps mutagenic electrophiles such as NO(X) and complements alpha-tocopherol: physiological implications. Proc Natl Acad Sci U S A 1997 Apr 1;94(7):3217-22.

9. Bowry, et al. Tocopherol-mediated peroxidation. The prooxidant effect of vitamin E on the radical-initiated oxidation of human low-density lipoprotein. Journal of the American Chemical Society v. 115 (July 14 ‘93) p. 6029-44.

10. Upston JM, et al. Oxidation of free fatty acids in low density lipoprotein by 15-lipoxygenase stimulate nonenzymic, alpha-tocopherol-mediated peroxidation of cholesteryl esters. J Biol Chem 1997 Nov 28;272(48): 30067-74.

11. Thomas SR, et al. Cosupplementation with coenzyme Q prevents the prooxidant effect of alpha-tocopherol and increases the resistance of LDL to transition metal-dependent oxidation initiation. Arterioscler Thromb Vasc Biol 1996 May;16(5):687-96.

12. Thomas SR, et al. Inhibition of LDL oxidation by ubiquinol-10. A protective mechanism for coenzyme Q in atherogenesis? Mol Aspects Med 1997;18 Suppl:S85-103.

13. Stocker R, et al. Ubiquinol-10 protects human low density lipoprotein more efficiently against lipid peroxidation than does alpha-tocopherol. Proc Natl Acad Sci U S A 1991 Mar 1;88(5):1646-50.

14. Thomas SR, et al. Oxidation and antioxidation of human low-density lipoprotein and plasma exposed to 3-morpholinosydnonimine and reagent peroxynitrite. Chem Res Toxicol 1998 May;11(5):484-94.

15. Traber MG. Does Vitamin E Decrease Heart Attack Risk? Summary and Implications with Respect to Dietary Recommendations. J Nutr 2001 Feb;131(2):395S-397S.

16. Wu D, et al. Vitamin E and Macrophage Cyclooxygenase Regulation in the Aged. J Nutr 2001 Feb;131(2):382S-388S.

17. Neuzil J, et al. Induction of cancer cell apoptosis by {alpha}-tocopheryl succinate: molecular pathways and structural requirements. FASEB J 2001 Feb 1;15(2):403-415.

18. Cinar MG, et al. Effect of dietary vitamin E supplementation on vascular reactivity of thoracic aorta in streptozotocin-diabetic rats. Pharmacology 2001 Jan;62(1):56-64.

19. Galli F, et al. Vitamin E, lipid profile, and peroxidation in hemodialysis patients. Kidney Int 2001 Feb;59(Suppl 78):148-154.

20. Mydlik M, et al. A modified dialyzer with vitamin E and antioxidant defense parameters. Kidney Int 2001 Feb;59(Suppl 78):144-147.

21. Roghani M, et al. Neuroprotective effect of vitamin E on the early model of Parkinson’s disease in rat: behavioral and histochemical evidence (1). Brain Res 2001 Feb 16;892(1):211-217.

22. Grant CA, et al. Treatable forms of retinitis pigmentosa associated with systemic neurological disorders. Int Ophthalmol Clin 2001 Winter;41(1):103-10.

23. Goldstein P, et al. Sex bodies and synaptonemal complexes of Balb/C mice: antioxidant intervention of oxyradical insult. Cytobios 2001;104(405):7-23.

24. Takacs P, et al. Increased circulating lipid peroxides in severe preeclampsia activate NF-{kappa}B and upregulate ICAM-1 in vascular endothelial cells. FASEB J 2001 Feb 1;15(2):279-281.

25. Jishage Ki K, et al. alpha -Tocopherol Transfer Protein Is Important for the Normal Development of Placental Labyrinthine Trophoblasts in Mice. J Biol Chem 2001 Jan 19;276(3):1669-1672.

26. Packer L, et al. Molecular Aspects of alpha-Tocotrienol Antioxidant Action and Cell Signalling. J Nutr 2001 Feb;131(2):369S-373S.

27. Meydani M. Vitamin E and Atherosclerosis: Beyond Prevention of LDL Oxidation. J Nutr 2001 Feb;131(2):366S-368S.

28. Chow CK. Vitamin E Regulation of Mitochondrial Superoxide Generation. Biol Signals Recept 2001 Jan;10(1-2):112-124.

29. Kline K, et al. Vitamin E: Mechanisms of Action as Tumor Cell Growth Inhibitors. J Nutr 2001 Jan;131(1):161S-163S.

30. Freedman JE, et al. Vitamin E Inhibition of Platelet Aggregation Is Independent of Antioxidant Activity. J Nutr 2001 Feb;131(2):374S-377S.

31. Rodriguez-Porcel M, et al. Hypercholesterolemia impairs myocardial perfusion and permeability: role of oxidative stress and endogenous scavenging activity. J Am Coll Cardiol 2001 Feb;37(2):608-15.

32. Jenkins JK, et al. Vitamin E inhibits renal mRNA expression of COX II, HO I, TGFbeta, and osteopontin in the rat model of cyclosporine nephrotoxicity. Transplantation 2001 Jan 27;71(2):331-4.

33. Jialal I, et al. Is there a vitamin E paradox? Curr Opin Lipidol 2001 Feb;12(1):49-53.

34. Neuzil J, et al. Selective cancer cell killing by alpha-tocopheryl succinate. Br J Cancer 2001 Jan 5;84(1):87-9.

35. Rose AT, et al. Alpha-tocopherol succinate inhibits growth of gastric cancer cells in vitro. J Surg Res 2001 Jan;95(1):19-22.

36. Adeyemo D, et al. Antioxidants enhance the susceptibility of colon carcinoma cells to 5-fluorouracil by augmenting the induction of the bax protein. Cancer Lett 2001 Mar 10;164(1):77-84.

37. Korac B, et al. Doxorubicin toxicity to the skin: possibility of protection with antioxidants enriched yeast. J Dermatol Sci 2001 Jan;25(1):45-52.

38. Gupta R, et al. Antioxidant and hypocholesterolaemic effects of Terminalia arjuna tree-bark powder: a randomised placebo-controlled trial. J Assoc Physicians India 2001 Feb;49:231-5.

39. Peus D, et al. Vitamin E analog modulates UVB-induced signaling pathway activation and enhances cell survival. Free Radic Biol Med 2001 Feb 15;30(4):425-432.

40. Jialal I, et al. The Effect of alpha-tocopherol on Monocyte Proatherogenic Activity. J Nutr 2001 Feb;131(2):389S-394S.

41. Fischer M, et al. Crux medicorum ulcerated radiation-induced fibrosis - successful therapy with pentoxifylline and vitamin E. Eur J Dermatol 2001 Jan;11(1):38-40.

42. Shimizu T, et al. Effects of n-3 Polyunsaturated Fatty Acids and Vitamin E on Colonic Mucosal Leukotriene Generation, Lipid Peroxidation, and Microcirculation in Rats with Experimental Colitis. Digestion 2001;63(1):49-54.

43. Siu AW, et al. N-acetyl-serotonin reduces copper (I) ion-induced lipid peroxidation in bovine retinal homogenates. Acta Ophthalmol Scand 2001 Feb;79(1):69-71.

44. Katz DL, et al. Acute effects of oats and vitamin E on endothelial responses to ingested fat. Am J Prev Med 2001 Feb;20(2):124-129.

45. van Haaften RI, et al. alpha-tocopherol Inhibits Human Glutathione S-Transferase pi. Biochem Biophys Res Commun 2001 Jan 26;280(3):631-633.

46. Pratico D, et al. Circulating autoantibodies to oxidized cardiolipin correlate with isoprostane F(2alpha)-VI levels and the extent of atherosclerosis in ApoE-deficient mice: modulation by vitamin E. Blood 2001 Jan 15;97(2):459-464.

47. Giray B, et al. Cypermethrin-induced oxidative stress in rat brain and liver is prevented by vitamin E or allopurinol. Toxicol Lett 2001 Jan 3;118(3):139-46.

48. Pincheira J, et al. Fanconi anemia lymphocytes: effect of DL-alpha-tocopherol (Vitamin E) on chromatid breaks and on G2 repair efficiency. Mutat Res 2001 Jan 5;461(4):265-71.



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