CoChat
Sign Up
Cited by 74Skin Protection and AgingGenomics, phytochemicals, and oxidative stressmelanin and skin pigmentation

High-energy visible light at ambient doses and intensities induces oxidative stress of skin-Protective effects of the antioxidant and Nrf2 inducer Licochalcone A in vitro and in vivo

Open access
Mann, Tobias, Eggers, Kerstin, Rippke, Frank, Tesch, Mirko, Buerger, Anette, Darvin, Maxim E., Schanzer, Sabine, Meinke, Martina C. +2 more·2020·Photodermatology, Photoimmunology & Photomedicine
DOI 10.1111/phpp.12523PMC PMC7078816
Open this paper in CoChat — free accountOpen PDF

Abstract

Background: Solar radiation causes skin damage through the generation of reactive oxygen species (ROS). While UV filters effectively reduce UV‐induced ROS, they cannot prevent VIS‐induced (400‐760 nm) oxidative stress. Therefore, potent antioxidants are needed as additives to sunscreen products. Methods: We investigated VIS‐induced ROS formation and the photoprotective effects of the Nrf2 inducer Licochalcone A (LicA). Results: Visible spectrum of 400‐500 nm dose‐dependently induced ROS in cultured human fibroblasts at doses equivalent to 1 hour of sunshine on a sunny summer day (150 J/cm 2). A pretreatment for 24 hours with 1 µmol/L LicA reduced ROS formation to the level of unirradiated cells while UV filters alone were ineffective, even at SPF50+. In vivo, topical treatment with a LicA‐containing SPF50 + formulation significantly prevented the depletion of intradermal carotenoids by VIS irradiation while SPF50 + control did not protect. Conclusion: LicA may be a useful additive antioxidant for sunscreens.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1111/phpp.12523

Cites

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The mechanism of photoprotection of licochalcone A involves stimulation of Nrf2/ARE signaling pathway.

    “The mechanism appeared to involve the stimulation of Nrf2/ARE signaling pathway, as preliminarily presented in a previous study [69,70].”

    From Licorice (Glycyrrhiza glabra, G. uralensis, and G. inflata) and Their Constituents as Active Cosmeceutical Ingredients (2022) · cites this paper as [69]

    The Introduction (page unavailable) says licochalcone A stimulates Nrf2/ARE signaling, and the Results report both Nrf2 activation and reduced light-induced ROS in treated cells. However, the Discussion (page unavailable) says the in vivo experiment could not reveal Nrf2-dependent effects and that demonstrating antioxidant efficacy due to Nrf2 induction requires future study. The proposed photoprotective mechanism is therefore plausible but not established by this paper. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

The citation lists haven’t been fetched yet

References 85 · Cited by 74

Research works printed but not linked: 79

  1. [2]Schroeder P, Lademann J, Darvin ME, et al. Infrared radiation‐induced matrix metalloproteinase in human skin: implications for protection. J Invest Dermatol. 2008; 128(10): 2491‐ 2497. 18449210
  2. [3]Höhn A, Hartmann P, Gebhart V, Sonntag J, Grune T, Jung T. Actual isothermal effects of water‐filtered infrared A‐irradiation. Photochem Photobiol. 2015; 91: 887‐ 894. 25707293
  3. [4]Robert C, Bonnet M, Marque S, Numa M, Doucet O. Low to moderate doses of infrared A irradiation impair extracellular matrix homeostasis of the skin and contribute to skin photodamage. Skin Pharmacol Physiol. 2015; 28: 196‐ 204. 25676694
  4. [5]Zastrow L, Lademann J. Light ‐ instead of UV protection: new requirements for skin cancer prevention. Anticancer Res. 2016; 2016(36): 1389‐ 1393. 26977040
  5. [6]Barolet D, Christiaens F, Hamblin MR. Infrared and skin: friend or foe. J Photochem Photobiol B. 2016; 155: 78‐ 85. 26745730 PMC4745411
  6. [7]Diffey B, Cadars B. An appraisal of the need for infrared radiation protection in sunscreens. Photochem Photobiol Sci. 2016; 15: 361‐ 364. 26846677
  7. [9]Diffey B. Solar spectral irradiance and summary outputs using Excel. Photochem Photobiol. 2015; 91: 553‐ 557. 25644778
  8. [10]Kielbassa C, Roza L, Epe B. Wavelength dependence of oxidative DNA damage induced by UV and visible light. Carcinogenesis. 1997; 18: 811‐ 816. 9111219
  9. [11]Young RW. Sunlight and age‐related eye disease. J Natl Med Assoc. 1992; 84: 353‐ 358. 1507250 PMC2637688
  10. [14]Liebmann J, Born M, Kolb‐Bachofen V. Blue‐light irradiation regulates proliferation and differentiation in human skin cells. J Invest Derm. 2010; 130: 259‐ 269. 19675580
  11. [15]Bennet D, Viswanath B, Kim S, An JH. An ultra‐sensitive biophysical risk assessment of light effect on skin cells. Oncotarget. 2017; 8(29): 47861‐ 47875. 28599308 PMC5564611
  12. [16]Masson‐Meyers DS, Bumah VV, Enwemeka CS. A comparison of four methods for determining viability in human dermal fibroblasts irradiated with blue light. J Pharmacol Toxicol Methods. 2016; 79: 15‐ 22. 26780674
  13. [17]Zastrow L, Groth N, Klein F, Kockott D, Lademann J, Ferrero L. Detection and identification of free radicals generated by UV and visible light in ex vivo human skin. Int J Cosmet Sci. 2009; 31: 402‐ 404.
  14. [18]Lohan S, Müller R, Albrecht S, et al. Free radicals induced by sunlight in different spectral regions ‐ in vivo versus ex vivo study. Exp Dermatol. 2016; 25: 380‐ 385. 26910569
  15. [19]Nakashima Y, Ohta S, Wolf AM. Blue light‐induced oxidative stress in live skin. Free Rad Biol Med. 2017; 108: 300‐ 310. 28315451
  16. [21]Balic A, Mokos M. Do we utilize our knowledge of the skin protective effects of carotenoids enough? Antioxidants. 2019; 8: 259. PMC6719967 31370257
  17. [22]Darvin ME, Fluhr JW, Caspers P, et al. In vivo distribution of carotenoids in different anatomical locations of human skin: comparative assessment with two different Raman spectroscopy methods. Exp Dermatol. 2009; 18: 1060‐ 1063. 19650865
  18. [23]Choe CS, Ri JR, Schleusener J, Lademann J, Darvin ME. The non‐homogenous distribution and aggregation of carotenoids in the stratum corneum correlates with the organization of intercellular lipids in vivo. Exp Dermatol. 2019: 1‐ 7. 10.1111/exd.14018 31400168 · DOI
  19. [24]Mendrok‐Edinger C, Campice R, Gadsinski K, Schuetz R. Into the blue ‐ novel test reveals blue light damage, protection strategies. Cosmet Toiletr. 2018; 133(1): 13‐ 29.
  20. [25]Vandersee S, Beyer M, Lademann J, Darvin ME. Blue‐violet light irradiation dose dependently decreases carotenoids in human skin, which indicates the generation of free radicals. Oxid Med Cell Longev. 2015; 579675. 25741404 PMC4337113
  21. [26]Becker A, Klapczynski A, Kuch N, et al. Gene expression profiling reveals aryl hydrocarbon receptor as a possible target for photobiomodulation when using blue light. Sci Rep. 2016; 6: 33847 10.1038/srep33847 27669902 PMC5037386 · DOI
  22. [27]Patel A, Rotenberg S, Messer RLW, et al. Blue light activates phase 2 response proteins and slows growth of A431 epidermoid carcinoma xenografts. Anticancer Res. 2014; 34: 6305‐ 6314. 25368229
  23. [28]Rojo de la Vega M, Krajisnik A, Zhang DD, Wondrak G. Targeting Nrf2 for improved skin barrier function and photoprotection: focus on the achiote‐derived apocarotenoid bixin. Nutrients. 2017; 9: 1371. PMC5748821 29258247
  24. [30]Boonstra HE, van Weelden H, Toonstra J, van Vloten WA. Polymorphous light eruption: a clinical, photobiologic, and follow‐up study of 110 patients. J Am Acad Dermatol. 2000; 42: 199‐ 207. 10642673
  25. [31]Stratigos AJ, Antoniou C, Papathanakou E, et al. Spectrum of idiopathic photodermatoses in a Mediterranean country. Int J Dermatol. 2003; 42: 449‐ 454. 12786871
  26. [32]Haylett AK, Koumaki D, Rhodes LE. Solar urticaria in 145 patients: assessment of action spectra and impact on quality of life in adults and children. Photodermatol Photoimmunol Photomed. 2018; 34: 262‐ 268. 29533487
  27. [33]Du‐Tanh A, Debu A, Lalheve P, Guillot B, Dereure O, Peyron JL. Solar urticaria: a time‐extended retrospective series of 61 patients and review of literature. Eur J Dermatol. 2013; 12: 202‐ 207. 23587746
  28. [34]Passeron T. Melasma pathogenesis and influencing factors ‐ an overview of the latest research. J Eur Acad Dermatol Venereol. 2013; 27: 5‐ 6. 23205539
  29. [36]Dupont E, Gomez J, Bilodeau D. Beyond UV radiation: a skin under challenge. Int J Cosmet Sci. 2013; 35: 224‐ 232. 23406155
  30. [37]Mahmoud BH, Ruvolo E, Hexsel CL, et al. Impact of long‐wavelength UVA and visible light in melanocompetent skin. J Invest Dermatol. 2010; 130: 2092‐ 2097. 20410914
  31. [38]Ramasubramaniam R, Roy A, Sharma B, Nagalakshmi S. Are there mechanistic differences between ultraviolet and visible radiation induced skin pigmentation? Photochem Photobiol Sci. 2011; 10: 1887‐ 1893. 21993454
  32. [39]Duteil L, Cardot‐Leccia N, Quelle‐Roussel C, et al. Differences in visible light‐induced pigmentation according to wavelengths: a clinical and histological study in comparison with UVB exposure. Pigment Cell Melanoma Res. 2014; 27: 822‐ 826. 24888214
  33. [40]Randhawa M, Seo I, Liebel F, Southall MD, Kollias N, Ruvolo E. Visible light induces melanogenesis in human skin through a photoadaptive response. PLoS One. 2015; 20: e0130949. PMC4488093 26121474
  34. [41]Kohli I, Chaowattanapanit S, Mohammad TF, et al. Synergistic effects of long wavelength ultraviolet al and visible light on pigmentation and erythema. Brit J Dermatol. 2018; 178: 1173‐ 1180. 28877342
  35. [42]Kohli I, Nahhas AF, Braunberger TL, et al. Spectral characteristics of visible light‐induced pigmentation and visible light protection factor. Photodermatol Photoimmunol Photomed. 2019; 1‐ 7. 10.1111/phpp.12490 31152612 · DOI · Paper page
  36. [43]Haywood R. Relevance of sunscreen application method, visible light and sunlight intensity to free‐radical protection: a study of ex vivo human skin. Photochem Photobiol. 2006; 82: 1123‐ 1131. 17205635
  37. [44]Mahmoud BH, Hexsel CL, Hamzavi IH, Lim HW. Effects of visible light on the skin. Photochem Photobiol. 2008; 84: 450‐ 462. 18248499
  38. [45]Boukari F, Jourdan E, Fontas E, et al. Prevention of melasma relapses with sunscreen combining protection against UV and short wavelengths of visible light: a prospective randomized comparative trial. J Am Acad Dermatol. 2015; 72: 189‐ 190. 25443629
  39. [46]Kolbe L. How much sun protection is needed? Are we on the way to full‐spectrum protection? J Invest Dermatol. 2012; 132: 1756‐ 1757. 22695285
  40. [47]Nahhas AF, Abdel‐Malek ZA, Kohli I, Braunberger TL, Lim HW, Hamzavi IH. The potential role of antioxidants in mitigating skin hyperpigmentation resulting from ultraviolet and visible light‐induced oxidative stress. Photodermatol Photoimmunol Photomed. 2018: 1‐ 9. 10.1111/phpp.12423 30198587 · DOI
  41. [48]Diffey B, Osterwalder U. Labelled sunscreen SPFs may overestimate protection in natural sunlight. Photochem Photobiol Sci. 2017; 16: 1519‐ 1523. 28812776
  42. [49]Martini APM, Maja Campos PMBG. Influence of visible light on cutaneous hyperchromias: clinical efficacy of broad‐spectrum sunscreens. Photodermatol Photoimmunol Photomed. 2018; 34: 241‐ 248. 29381828
  43. [50]Duteil L, Esdaile J, Maubert Y, et al. A method to assess the protective efficacy of sunscreens against visible light‐induced pigmentation. Photodermatol Photoimmunol Photomed. 2017; 33: 260‐ 266. 28602025
  44. [51]Liebel F, Kaur S, Ruvolo E, Kollias N, Southall MD. Irradiation of skin with visible light induces reactive oxygen species and matrix‐degrading enzymes. J Invest Dermatol. 2012; 132: 1901‐ 1907. 22318388
  45. [52]Arndt S, Haag SF, Kleemann A, Lademann J, Meinke MC. Radical protection in the visible and infrared by a hyperforin‐rich cream ‐ in vivo versus ex vivo methods. Exp Dermatol. 2013; 22: 354‐ 357. 23614743
  46. [53]Haag SF, Tscherch K, Arndt S, et al. Enhancement of skin radical scavenging activity and stratum corneum lipids after the application of a hyperforin‐rich cream. Eur J Pharm Biopharm. 2014; 86: 227‐ 233. 23811220
  47. [54]Xiao‐Ying Y, Xiao‐Wen P, Guo‐Qiang Z, Jian‐You G. Salidroside's protection against UVB‐mediated oxidative damage and apoptosis is associated with the upregulation of Nrf2 expression. Photomed Laser Surg. 2017; 1(35): 49‐ 56. 27627465
  48. [55]Tao S, Justiniano R, Zhang DD, Wondrak GT. The Nrf2‐inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV. Redox Biol. 2013; 1: 532‐ 541. 24273736 PMC3836278
  49. [56]Tao S, Park SL, Rojo de la Vega M, Zhang DD, Wondrak GT. Systemic administration of the apocarotenoid bixin protects skin against solar UV‐induced damage through activation of NRF2. Free Rad Biol Med. 2015; 89: 690‐ 700. 26456052 PMC4684723
  50. [57]Gacesa R, Lawrence KP, Georgakopoulos ND, et al. The mycosporine‐like amino acids porphyra‐334 and shinorine are antioxidants and direct antagonists of Keap1‐Nrf2 binding. Biochimie. 2018; 154: 35‐ 44. 30071261 PMC6214812
  51. [59]Kolbe L. Biological cell protection by natural compounds, a second line of defense against solar radiation In: Wondrak GT, ed. Skin Stress Response Pathways. Cham, Switzerland: Springer International Publishing AG; 2016: 361‐ 378.
  52. [60]Kühnl J, Roggenkamp D, Gehrke SA, et al. Licochalcone A activates Nrf2 in vitro and contributes to licorice extract‐induced lowered cutaneous oxidative stress in vivo. Exp Dermatol. 2015; 24: 42‐ 47. 25381913
  53. [61]Liu J, Luo L, Zhang H, et al. Rapid screening for novel antioxidants in Glycyrrhiza inflata using high‐resolution peak fractionation. J Function Foods. 2015; 16: 40‐ 49.
  54. [62]Roggenkamp D, Falkner S, Stäb F, Petersen M, Schmelz M, Neufang G. Atopic keratinocytes induce increased neurite outgrowth in a coculture model of porcine dorsal root ganglia neurons and human skin cells. J Invest Dermatol. 2012; 132: 1892‐ 1900. 22418869
  55. [63]Kalyanaraman B, Darley‐Usmar V, Davies KJA, et al. Measuring reactive oxygen and nitrogen species with fluorescent probes: challenges and limitations. Free Rad Biol Med. 2012; 52: 1‐ 6. 22027063 PMC3911769
  56. [64]Darvin ME, Sterry W, Lademann J. Resonance Raman spectroscopy as an effective tool for the determination of antioxidative stability of cosmetic formulations. J Biophotonics. 2010; 3(1–2): 82‐ 88. 19681037
  57. [65]Haraguchi H, Ishikawa H, Mizutani K, Tamura Y, Kinoshita T. Antioxidative and superoxide scavenging activities of retrochalcones in Glycyrrhiza inflata. Bioorg Med Chem. 1998; 6: 339‐ 347. 9568287
  58. [66]De Delinasios GJ, Karbaschi M, Cooke MS, Young AR. Vitamin E inhibits the UVAI induction of “light” and “dark”cyclobutane pyrimidine dimers, and oxidatively generated DNA damage, in keratinocytes. Sci Rep. 2018; 8: 423. 29323251 PMC5764969
  59. [67]Zinflou C, Rochette PJ. Absorption of blue light by cigarette smoke components is highly toxic for retinal pigmented epithelial cells. Arch Toxicol. 2019; 93(2): 453‐ 465. 30426163
  60. [69]Besaratinia A, Kim S, Bates SE, Pfeifer GP. Riboflavin activated by ultraviolet al rradiation induces oxidative DNA damage‐mediated mutations inhibited by vitamin C. PNAS. 2007; 104(14): 5953‐ 5958. 17389394 PMC1851598
  61. [70]Mozahebb N, Arefian E, Amoozegar MA. Designing a whole cell bioreporter to show antioxidant activities of agents that work by promotion of the KEAP1–NRF2 signaling pathway. Sci Rep. 2019; 9: 3248. 30824775 PMC6397309
  62. [71]Grether‐Beck S, Marini A, Jaenicke T, Krutmann J. Photoprotection of human skin beyond ultraviolet radiation. Photodermatol Photoimmunol Photomed. 2014; 30: 167‐ 174. 24433486
  63. [72]Cefali LC, Ataide JA, Moriel P, Foglio MA, Mazzola PG. Plant‐based active photoprotectants for sunscreens. Int J Cosmet Sci. 2016; 38: 346‐ 353. 26919163
  64. [73]Ikehata H, Yamamoto M. Roles of the KEAP1‐NRF2 system in mammalian skin exposed to UV radiation. Toxicol Appl Pharmacol. 2018; 360: 69‐ 77. 30268578
  65. [74]Tang ZH, Li T, Tong YG, et al. A systematic review of the anticancer properties of compounds isolated from licorice (Gancao). Planta Med. 2015; 81: 1670‐ 1687. 26695708
  66. [75]Russo M, Spagnuolo C, Russo GL, et al. Nrf2 targeting by sulforaphane: a potential therapy for cancer treatment. Crit Rev Food Sci Nutr. 2018; 58(8): 1391‐ 1405. 28001083
  67. [76]Mizutani T, Sumida H, Sagawa Y, Okano Y, Masaki H. Carbonylated proteins exposed to UVA and to blue light generate reactive oxygen species through a type I photosensitizing reaction. J Dermatol Sci. 2016; 84: 314‐ 321. 27743910
  68. [77]Opländer C, Hidding S, Werners FB, Born M, Pallua N, Suschek CV. Effects of blue light irradiation on human dermal fibroblasts. J Photochem Photobiol B. 2011; 103: 118‐ 125. 21421326
  69. [78]Mignon C, Uzunbajakava NE, Castellano‐Pellicena I, Botchkareva NV, Tobin DJ. Differential response of human dermal fibroblast subpopulations to visible and near‐infrared light: potential of photobiomodulation for addressing cutaneous conditions. Lasers Surg Med. 2018; 50: 859‐ 882. 29665018
  70. [79]Toh PP, Bigliardi‐Qi M, Yap AM, Sriram G, Bigliardi P. Expression of peropsin in human skin is related to phototransduction of violet light in keratinocytes. Exp Dermatol. 2016; 25: 1002‐ 1005. 27676658
  71. [80]Castellano I, Uzunbajakava NE, Mignon C, Raafs B, Botchkarev VA, Thornton MJ. Does blue light restore human epidermal barrier function via activation of Opsin during cutaneous wound healing? Lasers Surg Med. 2019; 51(4): 370‐ 382. 30168605
  72. [81]Gondran C, Bressier G, Labarrade F, Bauza E, Cucumel K, Domloge N. Modulation of opsin photoreceptors and circadian protein expression after blue light exposure in normal human keratinocytes. J Invest Dermatol. 2016; 136: S58.
  73. [82]Regazzetti C, Sormani L, Debayle D, et al. Melanocytes sense blue light and regulate pigmentation through the Opsin3. J Invest Dermatol. 2018; 138: 171‐ 178. 28842328
  74. [83]Fischer MR, Abel M, Lopez Kostka S, Rudolph B, Becker D, von Stebut E. Blue light irradiation suppresses dendritic cells activation in vitro. Exp Dermatol. 2013; 22: 558‐ 560. 23879817
  75. [84]Castanedo‐Cazares JP, Hernandez‐Blanco D, Carlos‐Ortega B, Fuentes‐Ahumada C, Torres‐Álvarez B. Near‐visible light and UV photoprotection in the treatment of melasma: a double‐blind randomized trial. Photodermatol Photoimmunol Photomed. 2014; 30: 35‐ 42. 24313385
  76. [85]Stein P, Badminton MN, Rees DC. Update review of the acute porphyrias. Brit J Hematol. 2017; 176: 527‐ 538. 27982422
  77. [86]Walker DP, Vollmer‐Snarr HR, Eberting CL. Ocular hazards of blue‐light therapy in dermatology. J Am Acad Dermatol. 2012; 66: 130‐ 135. 21536341
  78. [87]Keemss K, Pfaff SC, Born M, Liebmann J, Merk HF, von Felbert V. Prospective, randomized study on the efficacy and safety of local UV‐free blue light treatment of eczema. Dermatology. 2016; 232: 496‐ 502. 27537360
  79. [88]Greaves AJ. The effects of narrowbands of visible light upon some skin disorders: a review. Int J Cosmet Sci. 2016; 38: 325‐ 345. 26708128

Authors
Mann, T., Eggers, K., Rippke, F., Tesch, M., Buerger, A., Darvin, M. E., Schanzer, S., Meinke, M. C., Lademann, J., & Kolbe, L.
Affiliations
  • Beiersdorf (Germany) (DE)
  • Charité – Universitätsmedizin Berlin (DE)
Corresponding author
Kolbe, Ludger
ORCID
Venue
Photodermatology, Photoimmunology & Photomedicine
Publisher
Wiley
Published
2019-11-17
Volume
36
Issue
2
Pages
135-144
ISSN
  • 0905-4383 (ISSN-L)
  • 1600-0781
DOI
10.1111/phpp.12523
PMC
PMC7078816
OpenAlex
W2982566306
Cited by
74
References
85
Citations by year
2026: 10 · 2025: 17 · 2024: 4 · 2023: 9 · 2022: 11 · 2021: 16 · 2020: 6
FWCI
8.57
Type
journal article
Language
en
Open access
Licence
Locations
  • Photodermatology Photoimmunology & Photomedicine (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Dermatology › Skin Protection and Aging
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Genomics, phytochemicals, and oxidative stress
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › melanin and skin pigmentation
Keywords
high-energy visible light, oxidative stress, skin, licochalcone A, reactive oxygen species, photoprotection, antioxidants, UV filters, carotenoids
MeSH terms
Antioxidants, Fibroblasts, Glycyrrhiza, Humans, Sunlight, Sunscreening Agents, Oxidative Stress, Dermis, Chalcones, NF-E2-Related Factor 2

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review