Dietary Lycopene Protects SKH-1 Mice Against Ultraviolet B-Induced Photocarcinogenesis.

Lycopene, an acyclic hydrocarbon, non-provitamin A carotenoid, is a potent antioxidant with well-documented anticancer properties. In this study, we investigated the effects of dietary lycopene on sub-acute and chronic ultraviolet B (UVB)-induced skin carcinogenesis in SKH-1 mice. Groups of three mice were fed with a nonsupplemented or 1% lycopene diet for two weeks before and throughout two weeks of UVB irradiation (30 mJ/cm2 UVB, thrice weekly).

Protection From Environmental Skin Damage With Topical Antioxidants.

Skin is an efficient protective barrier armed with an intricate network of antioxidants. External environmental stress diminishes and sometimes overwhelms these innate protective mechanisms; aging slows their efficacy. Topical antioxidants enhance natural endogenous defenses to create an indwelling reservoir for sustained protection with far higher concentrations than possible with oral intake.

Mechanisms of aging and development-A new understanding of environmental damage to the skin and prevention with topical antioxidants.

Recent research has given us new insights into the molecular biology of extrinsic aging of the skin. Not only does UV irradiation directly cause photoaging of the skin, but also environmental pollutants significantly damage exposed skin by several mechanisms. Exposure to the noxious gases of air pollution with simultaneous exposure to UVA can act synergistically to initiate skin cancer.

The effects of topical L-selenomethionine on protection against UVB-induced skin cancer when given before, during, and after UVB exposure.

Previous studies in mice have shown that topical L-selenomethionine (SeMet) can prevent UVB-induced skin cancer when applied continuously before, during, and after the radiation exposure. With topical application of SeMet, selenium levels were shown to increase in the skin and liver, as well as in tumor tissue. Thus, possibly, the timing of SeMet application could affect the degree of inhibition of UVB-tumorigenesis (or maybe even enhance tumorigenesis at some stage).

Interaction of vitamins C and E as better cosmeceuticals.

Although many cosmeceutical formulations contain vitamin C and/or vitamin E, very few are actually effective in topical application. First because there is only a low concentration, second because the stability is compromised as soon as the product is opened and exposed to air and light, and third because the form of the molecule (an ester or a mixture of isomers) is not absorbed or metabolized effectively by the skin. However, when a stable formulation delivers a high concentration of the nonesterified, optimal isomer of the antioxidant, vitamins C and E do indeed inhibit the acute ultraviolet (UV) damage of erythema, sunburn, and tanning as well as chronic UV photoaging and skin cancer.

Effects of topical L-selenomethionine with topical and oral vitamin E on pigmentation and skin cancer induced by ultraviolet irradiation in Skh:2 hairless mice.

Background: The antioxidants selenium and vitamin E can be effective in reducing acute and chronic ultraviolet (UV)-induced skin damage.

Objective: This study investigated whether topical L-selenomethionine with topical RRR-alpha-tocopherol (Eol) or oral RRR-alpha-tocopheryl acetate (Eac) can reduce the incidence of UV-induced skin damage more than treatment with each alone.

Methods: Skh:2 hairless pigmented mice were treated with lotion vehicle, L-selenomethionine lotion, Eol lotion, oral Eac, L-selenomethionine plus Eol lotion, or L-selenomethionine lotion plus oral Eac and exposed to UVB.