Affiliations: Department of Nutrition and Food Science, Ochanomizu
University, 2-1-1, Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan | Takeda Chemical Industries, Japan | Fuji Biomedix Co. Ltd., Japan
Abstract: The effect of simultaneous administration of vitamin C (ascorbic
acid), L-cystein (Cys) and vitamin E (tocopherol) on the melanogenesis in vivo
and in vitro was studied. Forty-eight brownish guinea pigs were divided into 4 groups as
follows: VC group, VC+Cys group, VC+Cys+VE group and control group. They were
given these vitamins by oral administration every day. UV-B exposure (0.384
J/cm^2) on their depleted back skin was done at the day 8,
10, 12, 15 17 and 19. After UV-B irradiation, vitamins were administrated
further 3 weeks. The luminosity score was measured using a Color Reader CR-11
(Minolta, Co) and the numbers of DOPA-positive melanocytes of their back skin
were counted. B16 melanoma cells were incubated with VC, N-acetyl cystein (NAC)
and VE. After 4 days of incubation, cells were harvested. The melanin contents
and the tyrosinase activities in cells were measured. The luminosity score in the VC+VE+Cys group was higher than those in
the other groups. The numbers of DOPA-positive melanocytes of guinea pigs
treated with VC, VE and Cys were significantly decreased compared with those in
VC group. In B16 melanoma cells, simultaneous treatment of VC, VE and NAC was
the most effective to decrease the melanin contents and to inhibit tyrosinase
activity.
