The inhibitory effect of DL-alpha-tocopheryl ferulate in lecithin on melanogenesis

Anticancer Res. 1999 Sep-Oct;19(5A):3769-74.

Abstract

Oral vitamin E (alpha-tocopherol) supplementation has been reported to improve facial hyperpigmentation. The compound of alpha-tocopherol and ferulic acid, also an antioxidant connected with an ester bond, alpha-tocopheryl ferulate (alpha-TF) can absorb ultraviolet (UV) radiation and thus maintain tocopherol in a stable state. Our aim was to determine whether alpha-TF can be applied to improve and prevent facial hyperpigmentation induced by UV as a whitening agent as well as an antioxidant. In this study, the effects of alpha-TF on melanogenesis were examined using cultured human melanoma cells and normal human melanocytes in vitro. alpha-TF solubilized in 0.5% lecithin inhibited melanization significantly at the concentration of 30 micrograms/ml compared with arbutin (100 micrograms/ml), kojic acid (100 micrograms/ml), ascorbic acid (600 micrograms/ml), and tranexamic acid (600 micrograms/ml). alpha-TF had no effect on the protein amounts of tyrosinase, TRP (tyrosinase related protein)-1, and TRP-2 of human melanoma cells exposed to UV radiation, but inhibited tyrosine hydroxylase activity. alpha-TF neither directly inhibited tyrosinase activity of the large granule fraction extracted from melanoma cells, nor modulated glycosylation of tyrosinase. These results suggest that alpha-TF may be a candidate for whitening agent which suppresses melanogenesis, possibly by inhibiting tyrosine hydroxylase activity in an indirect manner. Further, alpha-TF decreased the amount of 8-hydroxydeoxyguanosine produced indirectly through active oxygen species (AOS) in guinea pig skin exposed to 2 times the minimal erythema dose of UVB radiation, but did not suppress the direct formation of cyclobutane pyrimidine dimers and (6-4) photoproducts. Thus alpha-TF may reduce AOS-induced DNA damage and thereby contribute at least in part to suppressing or retarding skin cancer development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8-Hydroxy-2'-Deoxyguanosine
  • Animals
  • Blotting, Western
  • Coumaric Acids / administration & dosage
  • Coumaric Acids / pharmacology*
  • DNA / radiation effects
  • Deoxyguanosine / analogs & derivatives
  • Deoxyguanosine / biosynthesis
  • Guinea Pigs
  • Humans
  • Melanins / biosynthesis*
  • Monophenol Monooxygenase / antagonists & inhibitors
  • Phosphatidylcholines / administration & dosage*
  • Pigmentation Disorders / drug therapy
  • Skin / metabolism
  • Skin / radiation effects
  • Tumor Cells, Cultured
  • Ultraviolet Rays
  • Vitamin E / administration & dosage
  • Vitamin E / pharmacology*

Substances

  • Coumaric Acids
  • Melanins
  • Phosphatidylcholines
  • Vitamin E
  • 8-Hydroxy-2'-Deoxyguanosine
  • DNA
  • ferulic acid
  • Monophenol Monooxygenase
  • Deoxyguanosine