UPTAKE AND BIOCONVERSION OF ALPHA-TOCOPHERYL ACETATE TO ALPHA-TOCOPHEROL IN SKIN OF HAIRLESS MICE

The photoprotective effect of topically applied alpha-tocopheryl aceta te (vitamin E acetate), a stable derivative of alpha-tocopherol (vitam in E), and its possible bioconversion to the active antioxidant specie s (alpha-tocopherol) was examined in skin tissue of female hairless mi ce (HRS/J) exposed to UV-B irradiation. Our results indicate that topi cally applied alpha-tocopheryl acetate is absorbed into and retained b y skin tissue. Furthermore, skin tissue from UV-B-irradiated animals t hat received daily topical alpha-tocopheryl acetate treatments contain ed significantly higher levels (P < 0.001) of alpha-tocopheryl acetate than non-UV-B-irradiated mice that received identical daily topical a lpha-tocopheryl acetate treatments. Finally, free alpha-tocopherol lev els in skin also were significantly increased (P < 0.001) by topical a pplications of alpha-tocopheryl acetate and skin levels of free alpha- tocopherol were significantly greater (P < 0.001) in UV-B-irradiated a nimals that received daily topical alpha-tocopheryl acetate treatments than in non-UV-B-irradiated animals. These results suggest that UV-B irradiation enhances both the absorption of alpha-tocopheryl acetate a nd its bioconversion to free alpha-tocopherol.