1993 年 27 巻 3 号 p. 409-414
The inhibitory effects of magnesium ascorbyl phosphate (VC-PMG) on melanogenesis were investigated in vitro using purified tyrosinase, B16F10 murine melanoma cell extract, and KHm-1/4 human melanoma cells. VC-PMG inhibited tyrosinase activity at a concentration of more than 0.001% for the purified tyrosinase, at a concentration of more than 0.01% for the B16F10 murine melanoma cells extract, and at a concentration of 0.1% for the KHm-1/4 human melanoma cells.
Percutaneous absorption of 14C-labeled VC-PMG was examined by applying creams containing 3% VC-PMG onto dermatomed human cadaver skin. After 48 hours, VC-PMG was retained in the skin at levels of less than 2% of the applied dose.
The lightening effects of VC-PMG on hyperpigmentation disorders, such as ephelides, chloasma, and senile freckle, in human skin in vivo were also studied. Cream containing 10% VC-PMG was applied to the pigmented area of 34 patients' faces twice a day for three months. Measurement by a color difference meter showed that the color of those pigmentations for 26 patients was lightened due to the topical application of VC-PMG cream. VC-PMG cream was also applied to non-pigmented area of 27 out of 34 patients. VC-PMG cream was also effective in lightening on 11 out of 27 healthy skin.
These results suggested that VC-PMG was absorbed by topical application, and stayed in the skin, and inhibited tyrosinase activity of melanocytes. In vivo results clearly showed that topical application of VC-PMG can be effective in lightening human skin pigmentations.