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(a) Decay kinetics of UV induced IPD at different doses. (b) Decay kinetics of visible dose induced IPD. Both UV and visible radiation induced IPD show similar decay patterns and follow first order decay equation D L *( t ) = D L *(0) exp( - kt ) + b . The rate constants k are very similar in value (0.028–0.032 min - 1 ) indicating that the transient species responsible
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Most of the studies on sunlight-induced pigmentation of skin are mainly focused on ultraviolet (UV) radiation-induced pigmentation and ways to prevent it. Recent studies have shown that the visible component of sunlight can also cause significant skin pigmentation. In the current study, the extent of pigmentation induced by UV and visible regions o...
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Context 1
... study the differences between of UV and visible radiation induced IPD, the decay kinetics of the transient species was tracked at regular intervals. The decay kinetics of IPD over a three hour period after exposure to different doses of UV and visible radiation are shown in Fig. 4a and Fig. 4b respectively. The IPD induced by UV and visible radiation are similar in magnitude and both pigmentations show very similar decay rates. From Fig. 4a and Table 3. The rate of decay k for both UV and visible radiation-induced pigmentation was independent of dose and found to be in the range of 0.028 to 0.032 min -1 . Under ...
Context 2
... study the differences between of UV and visible radiation induced IPD, the decay kinetics of the transient species was tracked at regular intervals. The decay kinetics of IPD over a three hour period after exposure to different doses of UV and visible radiation are shown in Fig. 4a and Fig. 4b respectively. The IPD induced by UV and visible radiation are similar in magnitude and both pigmentations show very similar decay rates. From Fig. 4a and Table 3. The rate of decay k for both UV and visible radiation-induced pigmentation was independent of dose and found to be in the range of 0.028 to 0.032 min -1 . Under the exposure ...
Context 3
... of the transient species was tracked at regular intervals. The decay kinetics of IPD over a three hour period after exposure to different doses of UV and visible radiation are shown in Fig. 4a and Fig. 4b respectively. The IPD induced by UV and visible radiation are similar in magnitude and both pigmentations show very similar decay rates. From Fig. 4a and Table 3. The rate of decay k for both UV and visible radiation-induced pigmentation was independent of dose and found to be in the range of 0.028 to 0.032 min -1 . Under the exposure doses studied, the transient pigmentation DL*(0) reaches a saturation value of about 3 and 2.5 L* units for UV and visible radiation, respectively. ...
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Citations
... While the primary focus of SR-induced pathologies has historically centered on the consequences of ultraviolet (UV) radiation, humans are exposed to visible light (VL, 400-700 nm), 12 to 14 orders of magnitude greater than UV. 1 Wavelengths within the VL spectrum penetrate the full thickness of the epidermis and dermis, extending into the subcutaneous adipose layer; 2 whereas UVA penetration does not extend beyond the dermis, and UVB only penetrates the epidermis. 3 In addition to exposure from SR, VL is transmitted from flash lamps, computers, televisions, and cell phones. ...
Background:
Iron oxides, antioxidants, and pigmentary titanium dioxide are sunscreen additive ingredients that enhance visible light protection, reduce associated hyperpigmentation, and protect against certain photosensitive dermatoses There are currently no standardized recommendations for visible light protection with these additive ingredients, leading to varied clinical recommendations.
Objectives:
This study aimed to evaluate dermatology practitioners' counseling practices for visible light protection.
Methods:
An electronic survey was distributed to dermatology practitioners. Survey responses were compiled for analysis, and statistical significance was calculated using a standard 95% confidence interval.
Results:
91.68% of 974 respondents actively counsel patients about visible light protection, primarily emphasizing its role in exacerbating pigmentation in patients with melanin-rich skin (70.92%). Of these, 10.34% recommended sunscreens with visible light protective additive ingredients specifically for patients with melanin-rich skin, and 48.89% recommended them for managing melasma or post-inflammatory hyperpigmentation. Iron oxide additive ingredients were most frequently recommended (90.92%), followed by antioxidants (69.08%) and pigmentary TiO2, (58.85%). 8.32% of respondents reported not counseling patients about visible light protection, with major reasons encompassing the lack of standardized guidelines (50.62%), challenges in recommending suitably tinted sunscreens (27.16%), limited availability of sunscreen options (23.46%), and insufficient supportive data (18.52%).
Conclusion:
There is a need for increased education and awareness regarding visible light protection strategies and the identification of patients who may benefit the most from a targeted photoprotective strategy. Establishing standardized guidelines and broadening the availability of sunscreen options conferring visible light protection may help address these gaps. J Drugs Dermatol. 2024;23(11):965-971. doi:10.36849/JDD.8159.
... Multiple studies have shown that VL has synergistic effects with long-wavelength UVA1 on pigmentation [6,41,42]. VL-induced hyperpigmentation was found more potent and long-lasting than UVA1-induced hyperpigmentation in individuals with dark skins [6,43], even though the mechanism of hyperpigmentation caused by VL has been proved similar to that caused by UV [44]. Typically, three mechanisms are involved in the responsive reaction of melanocytes to VL, with increased melanin content: immediate pigment darkening (IPD), persistent pigment darkening (PPD), and delayed tanning (DT) [45]. ...
Electromagnetic radiation, notably visible light (VL), has complicated effects on human skin, particularly pigmentation, which have been largely overlooked. In this review, we discuss the photobiological mechanisms, pathological effects, clinical applications and therapeutic strategies of VL at varying wavelengths on melanocyte biology and skin pigmentary disorders. Different VL wavelengths may impose positive or negative effects, depending on their interactions with specific chromophores, photoaging, ROS production, circadian rhythm and other photon-mediated reactions. Further in vivo and in vitro studies are required to establish the pathologic mechanisms and application principles of VL in pigmentary disorders, as well as optimal photoprotection with coverage against VL wavelengths.
... UV was found to be more powerful (25 times) than VL in inducing the same level of pigmentation. 30 By using in parallel UVA1 and VL exposures, Mahmoud et al. 24 confirmed that both conditions could induce pigmentation although the minimal pigmentary dose is higher for VL. More recently, using halogen sources, volunteers with phototypes IV-VI were exposed to UVA1 (0.44%) + VL or VL alone. ...
... In this natural sunlight study, the contribution of UV and VL in FSPT IV-V subjects was compared with the same type of study design: that is using a full spectrum (natural sun), filtered by optical filters. Two, 5 or 7 days after the last exposure, the pigmentation induced by full solar spectrum light was greater than that induced by UV and VL individually, the former being higher than that induced by VL. 30 Using two different halogen sources delivering UVA1 + VL (0.4% UVA1 + 99.4% VL + 0.75% IR) or VL (97.9% VL + 2.05% IR), Kohli et al. showed a greater pigmentation with UVA1 + VL compared with VL alone. The authors considered that the low dose of UVA1 (2.4 J/cm 2 ) was not sufficient to induce pigmentation by itself, suggesting a synergistic effect of VL and trace amounts of UVA1. ...
Background:
Solar light induces or aggravates hyperpigmentation issues. The contribution of UVA1, as well as visible light (VL), especially high-energy blue-violet visible (HEV) light, is now clearly established.
Objectives:
This work aimed at determining the relative contribution of UVA1, HEV and VL wavelength bands and their sub-domains in pigmentation induction.
Methods:
Two clinical studies using solar simulators equipped with specific bandpass physical filters were carried out. Volunteers (FSPT III-IV) were exposed on the back to UVA1 + HEV (350-450 nm), UVA1 (350-400 nm), HEV (400-450 nm) or part of UVA1 + HEV (370-450 nm) in Study 1 (n = 27) and to VL (400-700 nm), HEV (400-450 nm), Blue (400-500 nm), Green (500-600 nm) and Green+Red (500-700 nm) domains in Study 2 (n = 25). Pigmentation level was assessed by visual scoring and colorimetry at different time points postexposure, up to Day 43.
Results:
Induced pigmentation was detected in all exposed conditions, peaking at 2 h and thereafter progressively decreasing but remaining persistent up to Day 43. In Study 1, UVA1 showed an additive effect with HEV, with a significant contribution coming from the Longest UVA1 rays (370-400 nm). Study 2 demonstrated that 24 h postexposure, the Blue domain accounted for 71% of VL-induced pigmentation, the HEV one for 47%, the Green one for 37% and the Green+Red one for 36%, confirming no significant effect for Red light.
Conclusions:
Altogether, these results underline the need for UVA1 photoprotection up to 400 nm and highlight the importance of protecting the skin from solar VL wavelengths and especially from HEV, Blue and Green light, to limit induced pigmentation.
... After being absorbed by ePS and subsequently triggering the photosensitized oxidation reactions, UVA causes widespread oxidative stress, DNA lesions, malfunction in several organelles, mutagenesis and carcinogenesis [27,29,37,51,53,54]. Although the effects of VL are not yet considered in most sun-protection strategies, several reports have described the capacity of VL to induce strong and persistent pigmentation in human skin [16,[55][56][57][58][59][60]. Setlow and co-authors showed that the action spectra of melanoma induction peaks in the UVA, and extents to the blue region of VL [61]. ...
Visible light (VL) surely affects human skin in several ways, exerting positive (tissue regeneration, pain relief) and negative (oxidation, inflammation) effects, depending on the radiation dose and wavelength. Nevertheless, VL continues to be largely disregarded in photoprotection strategies, perhaps because the molecular mechanisms occurring during the interaction of VL with endogenous photosensitizers (ePS) and the subsequent biological responses are still poorly understood. Besides, VL encompass photons with different properties and interaction capacities with the ePS, but there are no quantitative comparisons of their effects on humans. Here, we studied the effects of physiologically relevant doses of four wavelengths ranges of VL, i.e. (in nm), 408-violet, 466/478-blue, 522-green, 650-red, in immortalized human skin keratinocytes (HaCaT). The level of cytotoxicity/damage follows the order: violet>blue >green>red. Violet and blue light induced the highest levels of Fpg-sensitive lesions in nuclear DNA, oxidative stress, lysosomal and mitochondrial damage, disruption of the lysosomal-mitochondrial axis of cell homeostasis, blockade of the autophagic flux, as well as lipofuscin accumulation, greatly increasing the toxicity of wideband VL to human skin. We hope this work will stimulate in development of optimized sun protection strategies.
... In the past decade, the focus has shifted to the other wavelengths of light namely visible light (400-700 nm) and infrared radiation (IR; 700-1400 nm) which form a major part of the solar spectrum, 45 and 54%, respectively. These longer wavelengths penetrate deeper into the skin and can induce ROS and potentially cause erythema in light skin and pigmentary changes in individuals with darker skin types [92,[98][99][100][101]. Furthermore, susceptibility to pigmentation by visible and IR radiation was shown to reside in darker skin types more than Caucasian skin [92,102,103]. ...
The pigment polymer, melanin is the major determinant of visible pigmentation of skin, hair, and eyes. Its synthesis within organelles called melanosomes in melanocytes and transfer to and distribution within keratinocytes in the epidermis regulates skin pigmentation. Sunlight and its ultraviolet radiation component have a well-established role in skin tanning, through increasing epidermal melanin. Additionally, linked to the pigmentary system are disorders of pigmentation, resulting in problems ranging from hypopigmentation to hyperpigmentation. This chapter provides an overview of the prominent hyperpigmentary manifestations such as post-inflammatory hyperpigmentation (e.g., that associated with acne), solar lentigo, melasma, and peri-orbital hyperpigmentation and recent advances in cosmetic interventions borne out of strong scientific understanding and consumer clinical studies.
... The mechanism of IPD and PPD from VL are similar to the reactions caused by UV, although the latter is more efficient at causing pigmentation. 24 Opsin-3, present in melanocytes, has been implicated in the pigmentary response to shorter wavelengths of VL, in particular blue light (415 nm). 25 The high p53 counts in intermediate subjects suggest that p53 upregulation in this group may have led to proopiomelanocortin (POMC) and alpha-melanocyte stimulating hormone (α-MSH) activation, a process that has previously been reported after UVR exposure. 26 Tanning (Figure 1) is believed to be an adaptive process, suggesting adequate cellular DNA repair ( Figure 4). ...
... In literature, lower power in dark skin did not lead to a phototoxic response but caused barely perceptible tanning. 24 Irradiance can affect the biological outcome more than dose, 32 which is a function of both power (Watts) and duration of ex- (Table S2). We can therefore attribute the phototoxic response to VL alone. ...
Background:
Visible light (VL) induces varying photobiological responses between skin types, likely influenced by inherent melanization. Individual typology angle (ITA) objectively measures skin types. We hypothesize that epidermal melanin content and distribution determine VL response.
Objectives:
This study describes clinical and histologic responses to VL and examines the potential role of melanin in the underlying mechanistic pathways.
Methods:
We grouped enrolled participants by ITA (Light=5, Intermediate=4, Dark=7) per colorimetry (CR-400, Konica Minolta). Photoprotected sites were exposed daily to 480 J/cm2 of VL (Fiber-Lite High Intensity Illuminator, Series 180, Dolan Jenner Industries Inc.) for 4 days (total=1920 J/cm2 ), as tolerated. Treated and control sites were biopsied 96 hours after first exposure. We used hematoxylin and eosin and Fontana-Mason to assess histological changes and melanin deposition, respectively. p53 and Ki67 immunohistochemical stains were done to assess DNA damage and proliferation. Matrix metalloproteinase (MMP)-1 expression was detected by immunohistochemical staining and immunofluorescence microscopy.
Results:
Darker skin did not tolerate the full VL regimen with blistering occurring in most subjects at doses of 220-880 J/cm2 . Intermediate and Dark skin showed tanning. Light skin developed erythema. p53 counts were highest in Intermediate, followed by Light skin, although this was not statistically significant. VL treatment led to MMP-1 expression and nuclear localization in keratinocytes in dark and intermediate but not in light skin, however differences between groups were not statistically significant.
Conclusions:
Skin types demonstrate unique biological responses to VL. The role of melanin in photoprotection is well defined. However, given the pro-apoptotic function of nuclear MMPs, we suggest a potential mechanism by which melanin may mediate VL induced phototoxicity.
... Although the damaging properties of Vis on skin are not completely assessed, the main described clinical impact of Vis is an increase in skin pigmentation. This effect can be induced by the Vis portion of natural sunlight (400-700 nm) and represents a contributor of sunlight radiation in hyperpigmentation [237]. This can also be observed after exposure to artificial Vis light sources, metal halogen [238] or solar simulation [239]. ...
Within solar ultraviolet (UV) light, the longest UVA1 wavelengths, with significant and relatively constant levels all year round and large penetration properties, produce effects in all cutaneous layers. Their effects, mediated by numerous endogenous chromophores, primarily involve the generation of reactive oxygen species (ROS). The resulting oxidative stress is the major mode of action of UVA1, responsible for lipid peroxidation, protein carbonylation, DNA lesions and subsequent intracellular signaling cascades. These molecular changes lead to mutations, apoptosis, dermis remodeling, inflammatory reactions and abnormal immune responses. The altered biological functions contribute to clinical consequences such as hyperpigmentation, inflammation, photoimmunosuppression, sun allergies, photoaging and photocancers. Such harmful impacts have also been reported after the use of UVA1 phototherapy or tanning beds. Furthermore, other external aggressors, such as pollutants and visible light (Vis), were shown to induce independent, cumulative and synergistic effects with UVA1 rays. In this review, we synthetize the biological and clinical effects of UVA1 and the complementary effects of UVA1 with pollutants or Vis. The identified deleterious biological impact of UVA1 contributing to clinical consequences, combined with the predominance of UVA1 rays in solar UV radiation, constitute a solid rational for the need for a broad photoprotection, including UVA1 up to 400 nm.
... Solar radiation from visible light (VL, 400-700 nm) incites skin damage associated with persistent hyperpigmentation, erythema, extracellular-matrix degrading enzymes, and freeradical formation. [1][2][3][4][5][6][7][8][9] Additionally, synergistic effects of VL and long wavelength UVA1 Pigmentary changes caused by VL+UVA1 have been shown to occur in three phases: ...
Objective:
The synergistic effects of VL and long wavelength UVA1 (VL+UVA1, 370-700 nm) on inducing pigmentation and erythema in skin have been demonstrated and linked to exacerbation of dermatologic conditions including melasma and post-inflammatory hyperpigmentation. This study aims to compare the photoprotection of organic sunscreens enriched with antioxidant (AO) combinations against VL+UVA1 induced biologic effects. The efficacy was compared to that offered by a commercially available tinted sunscreen.
Methods:
Ten healthy adult subjects with Fitzpatrick skin phototypes IV-VI were enrolled (nine completed). VL+UVA1 dose of 380 J/cm2 was utilized. Assessment methods were polarized photography, investigator global scoring, and diffuse reflectance spectroscopy (DRS). Measurements were obtained at baseline and immediately, 24 hours, and 7 days after irradiation.
Results:
Sites treated with tinted sunscreen product had significantly less pigmentation compared with untreated but irradiated skin at all time points. However, DRS results demonstrated that the 5-AO sunscreen performed comparably or better than all sunscreens tested with relatively lower dyschromia, delayed erythema and pigmentation.
Conclusion:
These results highlight the potential of AO enriched sunscreens to be photoprotective against VL+UVA1. The combination of efficacy and the cosmetic appearance of this product may provide wider acceptability which is crucial considering the limited available means of protection against this waveband.
... Vingt-cinq minutes d'exposition sont suffisantes pour induire une pigmentation mesurable chez des sujets de phototype IV-V. Dans cette étude les auteurs indiquent que la contribution des UV et de la lumière visible sont comparables mais avec une efficacité 25 fois supérieure des UV par J/cm²(Ramasubramaniam et al., 2011). Pour étudier le rôle respectif des différents sous-domaines colorielsde la lumière visible, Duteil et al. ont utilisé des LED avec un pic dans les longueurs d'ondes autour de 415 nm, correspondant au bleu-violet et d'autres avec un pic à 630 nm, correspondant à la lumière rouge. ...
Le soleil et particulièrement les ultraviolets (UV) entraînent des conséquences néfastes sur notre peau qui comprennent l’érythème, le photovieillissement, les désordres pigmentaires et les cancers cutanés. L’incidence et la sévérité de ces conséquences varie avec la pigmentation constitutive. Celle-ci peut être classée en fonction de l’Angle Typologique Individuel (ITA°) basé sur de paramètres colorimétriques. Pour étudier le lien entre pigmentation constitutive et sensibilité aux expositions UV, nous avons exposés des échantillons de pigmentation variable à des doses croissantes d’UVA+UVB et analysé les dommages biologiques liés à l’érythème. Nous avons défini la dose biologiquement efficace (DBE), sur la base de l’induction de cellules coup de soleil, et analysé les dégâts à l’ADN (dimères de pyrimidines, CPD). Nous avons montré une corrélation significative entre ITA° et DBE et une corrélation entre ITA° et CPD. Nous avons également analysé plus spécifiquement les dégâts au niveau de l’ADN des mélanocytes et montré que ceux-ci dépendent de l’ITA°. Ces résultats peuvent expliquer le risque plus élevé des peaux plus claires au développement cancers cutanés y compris le mélanome et au photovieillissement. Parce que la pigmentation constitutive dépend de la nature des mélanines (eu-phéomélanine) nous avons caractérisé le contenu en mélanine d’échantillons de peau de pigmentation variable. Nous avons démontré que la peau humaine contient environ 74% d’eumélanine et 26% de phéomélanine, quel que soit son degré de pigmentation. Les résultats confirment le faible contenu en eumélanine photoprotectrice des peaux les plus claires, expliquant leur plus grande sensibilité aux expositions UV.
... When the skin is exposed to 1 to 5 J/cm 2 , immediate pigment darkening (IPD) is observed. At doses higher than 5 J/ cm 2 , IPD can remain for longer and lead to persistent pigment darkening (PPD) (15). UVA and UVB radiation have different impacts on the skin. ...
... Since visible light includes a wide range of wavelengths, from the blue-violet spectrum to the red one, it is expected to have different photobiological impacts on the skin (7). Regarding skin pigmentation, a study by Ramasubramaniam et al. (15), conducted in India, reported that the spectrum of action of visible light and UV are very similar in inducing immediate pigment darkening (IPD), but UV is 25 times more efficient in inducing persistent pigment darkening (PPD). All the studies carried out to date demonstrated clinical relevance in the ability of visible light to induce pigmentation, therefore being a possible cause of pathologies, such as melasma and post-inflammatory hyperpigmentation, which occur mainly in more pigmented skin phototypes (10). ...
Social distancing is conducive to grow the impact of artificial light in the daily life of the worldwide population with reported consequences to the skin. Sunlight is also essential for human development, indeed, solar radiation is composed of different types of wavelengths, which generate different skin effects. It can be divided into ultraviolet (UV), infrared (IR), and visible. UV radiation (UVA and UVB) has cutaneous biological effects ranging from photoaging, immunosuppression to melanoma formation, through the production of reactive oxygen species (ROS), inflammation and elevation of the energy state of organic molecules, changing the DNA structure. IR radiation reaches deeper layers of the skin and is also related to the generation of ROS, photoaging and erythema while visible light is responsible for generating ROS, pigmentation, cytokine formation, and matrix metallopeptidases (MMPs). Furthermore, artificial light could be harmful to the skin, as it can generate ROS, hyperpigmentation, and stimulate photoaging. Currently, we briefly summarized the cutaneous biological effects of sunlight, as well as artificial light on skin and remarked the opportunity of the evolution of current photoprotective formulas through new strategies with broad spectrum protection.
