- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
752 Clinical effects of LED blue light on skin pigmentation and carotenoid depletion
摘要： The growing evidence that visible light - and especially blue light - contributes to detrimental effects of sun exposure to skin, is becoming a subject of controversial debate nowadays. In this study we aimed to assess blue light-induced pigmentation and carotenoid depletion in vivo. Furthermore, we wanted to show a protective effect of SPF50 sunscreen formulations in a double-blind, placebo-controlled trial. The UVA/B filter system included the microfine particles titanium dioxide and methylene bis-benzotriazolyl tetramethylbutylphenol that extend effectiveness into the blue light range. Comparisons between repetitive irradiation with LED blue light (450 ± 20 nm) with 45 J/cm2 over 5 consecutive days after daily product application (2 mg/cm2) and irradiation only once with 135 J/cm2 after product application over 6 days were performed on the back of the volunteers. The extent of pigmentation and carotenoid depletion was investigated with the assessment of the skin color (ITA°) by chromameter measurements and the in vivo carotenoid concentration via multiple spatially resolved reflectance spectroscopy, respectively. Assessments were performed 5 hours, 24 hours, 1 week and 2 weeks after the last irradiation. Fourteen subjects terminated the study. Both, the single high-dose and the repetitive exposure resulted in comparable, immediate (≤5h) increase of skin pigmentation and carotenoid degradation (p<0.001). Skin pigmentation and carotenoid depletion attenuated on all test conditions already one day after the last irradiation. Both effects were still evident one and two weeks after the last irradiation. The application of the cosmetic formulations including UV pigments that scatter in the blue light range significantly reduced pigmentation (p<0.001) right after irradiation that might be considered for holistic light protection beyond UV.
关键词： carotenoid depletion,SPF50 sunscreen,UVA/B filter system,skin pigmentation,blue light
更新于2025-09-12 10:27:22
-
Safety of light emitting diode‐red light on human skin: two randomized controlled trials
摘要： Background: Therapeutic applications of light emitting diode-red light (LED-RL) are expanding, yet data on its clinical effects are lacking. Objectives: To evaluate the safety of high fluence LED-RL (≥160 J/cm2). Methods: In two phase I, single-blind, dose escalation, randomized controlled trials, healthy subjects received LED-RL or mock irradiation to the forearm thrice weekly for three weeks at fluences of 160 to 640 J/cm2 for all skin types (STARS 1, n=60) and at 480 to 640 J/cm2 for non-Hispanic Caucasians (STARS 2, n=55). The primary outcome was the incidence of adverse events (AEs). The maximum tolerated dose was the highest fluence that did not elicit predefined AEs. Results: Dose-limiting AEs, including blistering and prolonged erythema, occurred at 480 J/cm2 in STARS 1 (n=1) and 640 J/cm2 in STARS 2 (n=2). AEs of transient erythema and hyperpigmentation were mild. No serious AEs occurred. Conclusions: LED-RL is safe up to 320 J/cm2 for skin of color and 480 J/cm2 for non-Hispanic Caucasian individuals. LED-RL may exert differential cutaneous effects depending on race and ethnicity, with darker skin being more photosensitive. These findings may guide future studies to evaluate the efficacy of LED-RL for the treatment of various diseases. Trial Registration: ClinicalTrials.gov, NCT02630303 and NCT03433222
关键词： Randomized Controlled Trial,Skin Pigmentation,Phototherapy,Low-Level Light Therapy
更新于2025-09-11 14:15:04