Vitamin E and Immune Function Kate Osei-Boadi MS Human Nutrition

Introduction The Immune system made up of: Innate – Skin, mucus membrane, acidic content of the stomach, antimicrobial peptides, NK cells and macrophages Adaptive – B and T cells

Factors affecting immunocompetence Variations in immune function exist in healthy individuals Genetics Age Gender Lifestyle Diet

Immune function Nutritional status important factor contributing to immunocompetence Many studies done to investigate the role of nutrients in immune function – Alone – Combinations

Vitamin E It is a fat soluble vitamin – Tocopherols – Tocotrienols Antioxidant role Immune function

Vitamin E and immune function in advanced colorectal cancer patients 750 mg vitamin E, 60 ug selenium and 90 mg vitamin C Fig. 1 Increased plasma α-tocopherol after vitamin E treatment Malmberg et. al., 2002,Clinical cancer research

Fig 2. Typical staining of IL-2 production in PMA/Ionomycin-activated T cells before and after vitamin E treatment Malmberg et. al., 2002,Clinical cancer research Vitamin E supplementation in advanced colorectal cancer patients

Fig. 4Enhanced CD4:CD8 ratios as a result of vitamin E treatment Fig. 3 The amount of IFN-γ (pg/100 l) produced by PBMCs stimulated by anti- CD3 mAb Vitamin E supplementation in advanced colorectal cancer patients Source :Malmberg et. al., Clinical cancer research

Vitamin E supplementation in the aged Diminished immunocompetence with age – T cells In a double blind placebo-controlled trial Vitamin E supplementation (800 mg dl α tocopherol) improved immune function in the elderly – Decreased production of PGE 2 and lipid peroxides Source Meydani et al., Am J. Clin. Nutr

DTH mmIL-2 kU/L Groupbeforeafterbeforeafter placebo16.5 ± ± ± ± 12.5 Vit E supplemented14.2 ± ± 3.5*35.6± ±12.6* Table 1. vitamin E supplementation on DTH and IL-2 production in the elderly Control cultures PHA stimulated cultures Groupbeforeafterbeforeafter pmol/L placebo7.3 ± ± ± ± 1.6 Vit E supplemented 7.8 ± ± ± ± 1.5* Table 2.Effect of vitamin E supplementation on PGE2 in the elderly Source Meydani et al., Am J. Clin. Nutr

Vitamin E induced enhancement of T cell function is independent of PGE2 Vitamin E enhanced immune function of old mice directly independent of macrophage PGE 2 lowering effect Purified T cells incubated with complete RPMI supplemented with 46 µM (200 IU/day in humans) Adolfsson et al., J Immunol

T cell function in old T cells not affected by absence of PGE2 Fig 5 Supplemental vitamin E increases T cell function by two mechanisms Adolfsson et al., J Immunol

Effect of vitamin E supplementation together with fish oil. Immuno enhancing effect of vitamin E hampered when it is consumed with fish oil – Plasma concentration of vitamin E in the presence of fish oil Wu et al., Journal of American college of nutrition

Group (# of subjects) Maximum diameterof induration mm mg/daybaseline3 months placebo31.4 ± ± 4.4 E ± ± 4.0* E ± ± 3.2* E ± ± 3.6* * Significantly different from the corresponding baseline at p 0.05 by paired student t-test Groups given 5 capsules/d of Omega-500™ and a capsule/d containing 100, 200, or 400 mg of vitamin E (dl--tocopherol in soybean oil, Hoffmann-LaRoche, Nutley, NJ), respectively. Wu et al., Journal of American college of nutrition Fig. 3 Effect of fish oil and vitamin E supplementation on DTH skin response in the elderly

Fig 6. Effect of dietary supplementation with fish oil and different levels of vitamin E on lymphocyte proliferation Increase in plasma α-tocopherol were not as profound as that reported in other studies where supplementation was done with vitamin E alone

Vitamin E supplementation and immune response to Herpes Simplex virus encephalitis BALB/c mice fed VE-D diet- TD VE-A diet dl-α-tocopherol acetate 38.4 mg/kg VE-S diet 384 mg/kg for 4 weeks Fig. 7. Forebrain IL-6, TNF-α, IL-1β and IL-10 gene expression in different vitamin E groups Sheridan and Beck, J. Nutr

Viral titer of HSV in the brain Fig. 8 Brain HSV titer in the hemisphere of the brain in VE- D, VE-A and VE-S mice

conclusion Eventhough vitamin E supplementation has been shown by several studies to improve immune function, others did not report any beneficial effect.