Background: Vitamin C, which is a strong anti-oxidant, plays an important role in maintaining physiological states. In dermatology, Vitamin C is used for treatment of various skin problems such as de-pigmentation of hyperpigmented spots. However, Vitamin C has limited stability and permeability, and development of a Vitamin C derivative with improved properties is needed.
Objective: We evaluated the effect of a lipophilic Vitamin C derivative, tetra-isopalmitoyl ascorbic acid (VC-IP), on ultraviolet (UV)-induced skin pigmentation, to determine its potential as a more effective form of Vitamin C.
Methods: The release of Vitamin C from VC-IP was examined using a reconstructed skin model following topical application of VC-IP. Anti-oxidative and anti-inflammatory activities of VC-IP were tested in cultured human keratinocytes. Subsequently, clinical test was done to clarify the effect of VC-IP on UVB-induced skin pigmentation.
Results: VC-IP released Vitamin C in physiological conditions and worked as pro-Vitamin C. In subsequent experiments, we found that VC-IP suppressed the elevation of intracellular peroxide after UVB irradiation, and enhanced cellular tolerance against UVB and reactive oxygen species such as hydrogen peroxide and tert-butyl hydroperoxide. Furthermore, VC-IP reduced the production of interleukin-1alpha and prostaglandin E2 in UVB-irradiated keratinocytes and suppressed melanocyte proliferation in conditioned culture medium prepared from UVB-irradiated keratinocytes. Finally, in a clinical study, topical application of a 3% VC-IP cream for 3 weeks suppressed pigmentation after UVB irradiation.
Conclusions: These results demonstrate that VC-IP is a precursor of Vitamin C, and effectively suppresses UVB-induced skin pigmentation, possibly through its anti-oxidative activity.