ABSTRACT
BACKGROUND: UV radiation induces damage to human skin. Protection of skin by an oral photoprotective agent would have substantial benefits. Objective We investigated the photoprotective effect of oral administration of an extract of the natural antioxidant Polypodium leucotomos (PL). METHODS: A total of 9 healthy participants of skin types II to III were exposed to varying doses of artificial UV radiation without and after oral administration of PL (7.5 mg/kg). At 24 hours after exposure the erythema reaction was assessed and paired biopsy specimens were obtained from PL-treated and untreated skin. RESULTS: A significant decrease in erythema was found in PL-treated skin (P < .01). Histologically, PL-treated biopsy specimens showed less sunburn cells (P < .05), cyclobutane pyrimidine dimers (P < .001), proliferating epidermal cells (P < .001), and dermal mast cell infiltration (P < .05). A trend toward Langerhans cell preservation was seen. CONCLUSION: Oral administration of PL is an effective systemic chemophotoprotective agent leading to significant protection of skin against UV radiation.
Subject(s)
Phytotherapy , Plant Extracts/therapeutic use , Polypodium , Skin/pathology , Sunburn/prevention & control , Administration, Oral , Adult , Erythema/pathology , Erythema/prevention & control , Female , Humans , Male , Mast Cells/drug effects , Middle Aged , Skin/immunology , Sunburn/pathology , Ultraviolet Rays/adverse effectsABSTRACT
BACKGROUND: The use of psoralen-UVA (PUVA) in patients of skin phototype I to II is limited by side effects of acute phototoxicity and possible long-term carcinogenesis. OBJECTIVE: We sought to assess oral Polypodium leucotomos (PL) extract in decreasing PUVA-induced phototoxicity of human skin on a clinical and histologic level. METHODS: A total of 10 healthy patients with skin phototypes II to III were exposed to PUVA alone (using 0.6 mg/kg oral 8-methoxypsoralen) and to PUVA with 7.5 mg/kg of oral PL. RESULTS: Clinically, phototoxicity was always lower in PL-treated skin after 48 to 72 hours (P<.005), and pigmentation was also reduced 4 months later. Histologically, PL-treated skin showed a significant numeric reduction of sunburn cells (P=.05), preservation of Langerhans cells (P< or =.01), decrease of tryptase-positive mast cell infiltration (P<.05), and decrease of vasodilation (P< or =.01). No differences were found in Ki-67+ proliferating cells. CONCLUSIONS: PL is an effective chemophotoprotector against PUVA-induced skin phototoxicity and leads to substantial benefits of skin protection against damaging effects of PUVA as evidenced by histology.
Subject(s)
Dermatitis, Phototoxic/prevention & control , Hyperpigmentation/prevention & control , PUVA Therapy/adverse effects , Phytotherapy , Plant Extracts/administration & dosage , Polypodium , Psoriasis/drug therapy , Administration, Oral , Adult , Dermatitis, Phototoxic/etiology , Dermatitis, Phototoxic/pathology , Female , Humans , Hyperpigmentation/etiology , Hyperpigmentation/pathology , Male , Middle Aged , Skin/pathology , Skin/radiation effectsABSTRACT
Lutein and zeaxanthin are carotenoids found in green leafy vegetables with interesting antioxidant properties. They are present in high concentrations in the fovea centralis of the human retina and their role in the prevention of age-related macula degeneration has been reported. We have investigated the effect of orally administered lutein and zeaxanthin in the cutaneous response to ultraviolet B irradiation. Female hairless SKh-1 mice receiving 0.4% and 0.04% lutein plus zeaxanthin-enriched diet for 2 wk were exposed to single doses of ultraviolet B radiation. Skin biopsies were taken at 24 and 48 h after irradiation and analyzed for the presence of apoptotic cells, proliferating cells, and expression of proliferating cell nuclear antigen. Our results show a clear ultraviolet-induced dose-dependent inflammatory response. Orally administered 0.4% lutein and zeaxanthin decreased significantly the edematous cutaneous response (p<0.01) as determined by the reduction of the UVB-induced increase of ear bifold thickening. Additionally, dietary carotenoids were efficient in reducing the ultraviolet B-induced increases in the percentage of proliferating cell nuclear antigen (p<0.05), bromodeoxyuridine (p<0.05), and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling-positive cells (p<0.01). These data demonstrate that oral supplementation of lutein and zeaxanthin diminishes the effects of ultraviolet B irradiation by reducing acute inflammatory responses and ultraviolet-induced hyperproliferative rebound.