Protection against Long Ultraviolet and/or Visible Light with Topical Dihydroxyacetone

Abstract

Dihydroxyacetone (DHA) chemically induces long ultraviolet (UV) and/or visible photoprotection into the stratum corneum as demonstrated by (a) long UV protection of albino rats which were psoralen-photosensitized to black fluorescent light and (b) sunlight protection of five patients with long UV and/or visible photosensitivity. Previously, DHA treatment of skin was considered to provide no protection against UV. For clinical use, the combination of DHA and lawsone (2-hydroxy-1,4-naphthoquinone) is preferred to DHA alone, because it provides rapid, positive protection over a range extending from short UV into the visible region of sunlight.

Turbo-PUVA: Dihydroxyacetone-Enhanced Photochemotherapy for Psoriasis

“…[4][5][6] Dihydroxyacetone offers 2-to 5-fold protection against UV-A. 6,7 Concentrations of DHA up to 15% provide up to 10-fold protection against PUVA-induced erythema, depending on concentration. 8 Bound DHA is also shed faster from psoriatic plaques than from uninvolved skin, the differential in DHA staining of psoriatic vs uninvolved skin being greatest at 72 hours.…”

Protection of Photosensitized Rats against Long Ultraviolet Radiation by Topical Application of Compounds with Structures Similar to That of Dihydroxyacetone

“…Conse quently, the voluminous information about SPF is of no value in judging what consti tutes a therapeutically effective PPF. For ex ample, DHA provided all-day protection to a patient with EPP who tolerated over 3 h sunlight before therapy, for a porphyrin pro tection factor of 'only' 2.4 [3], On the other hand, DHA increased the tolerance of a very sensitive patient from 5 to 90 min, thus providing a factor of 18.…”

“…Protection of EPP pa tients [3], who react strongly at 390-420 nm [1], extends the therapeutic spectrum of DHA. It has been reported that DHA plus lawsone (2-hydroxy-l,4-naphthoquinone) does not protect psoriatic patients undergo ing PUVA therapy [1], One would not expect a dramatic effect, since the high-intensity PUVA lamps would exceed most of the screening action of DHA.…”

“…The approach to development of protection against long ultraviolet (320-400 nm, UVA) radiation has been to modify UVB sunscreens to ex tend their absorption into the UVA region or select compounds with broad absorption bands at appropriate wavelengths. In con trast, dihydroxyacetone (DHA) reacts with the stratum corneum to produce a durable brown color that protects psoralensensitized rats against blacklight fluorescent lamps and patients with erythropoietic pro toporphyria (EPP) against sunlight [3].…”

Protection against Long Ultraviolet Radiation: Topical Browning Agents and a New Outlook

“…Since the brown pigment has little screening action against sunlight [19,20], DHA has been used as a cosmet ic supplement in conventional sunscreen preparations. The DHA reaction product provides a protection factor for 3 or 4 in rats subjected to PUVA conditions, and protects patients with erythropoietic protoporphyria against sunlight [21], When used with lawsone (2-hydroxy-l,4-naphthoquinone), the agent protects against several disorders involving sensitivity to UVA [22], Lawsone is employed to provide UVB protection; its orange-red color did not protect rats against PUVA conditions [21], Therefore, the brown skin color produced by DHA provides broad-spectrum protection against UVA and visible light.…”