This paper describes recent data on the effects of various skin formulations containing hydroxyacids (HAs) and related products on sun-exposed skin. The most frequently used classes of these products, such as α- and β-hydroxyacids, polyhydroxy acids, and bionic acids, are reviewed, and their application in cosmetic formulations is described. Special emphasis is devoted to the safety evaluation of these formulations, particularly on the effects of their prolonged use on sun-exposed skin. We also discuss the important contribution of cosmetic vehicles in these types of studies. Data on the effects of HAs on melanogenesis and tanning are also included. Up-to-date methods and techniques used in those explorations, as well as selected future developments in the cosmetic area, are presented. 1. Introduction The cosmetic market is growing rapidly internationally and shows no sign of slowing in the foreseeable future. Within skin care products, antiaging and sun protection products are the main driving forces in this trend. Contemporary cosmetics contain a large number of active ingredients, such as botanicals, antioxidants, hormones, and hydroxyacids (HAs) to name just a few. In this paper, we focus on the role that HAs play in cosmetic/skin care products, their safety evaluations, and their effects on sun-exposed skin. This paper covers selected new developments in the field which appeared since our previous review of this topic, and it also includes selected topics not covered in that paper [1]. 2. Presentation of HAs Structure and Classification HAs have significantly influenced skin care since their introduction to dermatology about 40？yrs ago [2]. Since their inclusion in cosmetic formulations, they have been used to treat acne, ichthyosis, keratoses, psoriasis, photoaged skin and other disorders [3]. Following these developments, HAs have been gradually added into a variety of cosmetic products for daily use and over extended time periods [4]. At present, glycolic acid, lactic acid, and salicylic acid are the most frequently used HAs in cosmetics. One of the most cited beneficial effects of HAs is the reported improvement of photoaged skin. The driving force behind the increase in HAs use in cosmetic dermatology and skin care systems has been their antiaging effects [5]. Based on their structure and function, HAs can be classified as α-HAs, β-Has, and salicylic acid (SA) and its derivatives. The most common representative of an α-HA is glycolic acid, which was one of the first HAs to be incorporated into cosmetic formulations [4]. Another α-HA being used
References
[1]
A. Kornhauser, S. G. Coelho, and V. J. Hearing, “Applications of hydroxy acids: classification, mechanisms, and photoactivity,” Clinical Cosmetic and Investigational Dermatology, vol. 3, pp. 135–142, 2010.
[2]
E. J. Van Scott and R. J. Yu, “Control of keratinization with alpha-hydroxy acids and related compounds. I. Topical treatment of ichthyotic disorders,” Archives of Dermatology, vol. 110, no. 4, pp. 586–590, 1974.
[3]
E. M. Jackson, “AHA-type products proliferate in 1993,” Cosmetic Dermatology, vol. 6, pp. 22–26, 1993.
[4]
R. J. Yu and E. J. Van Scott, “Alpha-hydroxyacids and carboxylic acids,” Journal of Cosmetic Dermatology, vol. 3, pp. 76–87, 2004.
[5]
B. Green, “After 30 years … the future of hydroxyacids,” Journal of Cosmetic Dermatology, vol. 4, pp. 44–45, 2005.
[6]
E. F. Bernstein, C. B. Underhill, J. Lakkakorpi et al., “Citric acid increases viable epidermal thickness and glycosaminoglycan content of sun-damaged skin,” Dermatologic Surgery, vol. 23, no. 8, pp. 689–694, 1997.
[7]
R. J. Yu and E.J. Van Scott, “Salicylic Acid: not a b-Hydroxy Acid,” Cosmetic Dermatology, vol. 10, article 27, 1997.
[8]
D. F. A. Andersen, “Final report on the safety assessment of glycolic acid, ammonium, calcium, potassium, and sodium glycolates, methyl, ethyl, propyl, and butyl glycolates, and lactic acid, ammonium, calcium, potassium, sodium, and tea-lactates, methyl, ethyl, isopropyl, and butyl lactates, and lauryl, myristyl, and cetyl lactates,” International Journal of Toxicology, vol. 17, no. 1, pp. 1–241, 1998.
National Toxicology Program, “Photocarcinogenic study of glycolic acid and salicylic acid in SKH-1 mice,” Tech. Rep. TR 524, NTP, 2007.
[11]
Y. P. Lu, Y. R. Lou, J. G. Xie et al., “Tumorigenic effect of some commonly used moisturizing creams when applied topically to UVB-pretreated high-risk mice,” Journal of Investigative Dermatology, vol. 129, no. 2, pp. 468–475, 2009.
[12]
F. Staeb, E. Gerber, and L. Kolbe, “Comment on "Tumorigenic effect of some commonly used moisturizing creams when applied topically to UVB-pretreated high-risk mice",” Journal of Investigative Dermatology, vol. 129, no. 2, pp. 515–516, 2009.
[13]
R. D. Ellefson, “Comment on "Tumorigenic effect of some commonly used moisturizing creams when applied topically to UVB-pretreated high-risk mice",” Journal of Investigative Dermatology, vol. 129, no. 2, pp. 513–514, 2009.
[14]
P. D. Forbes, “Moisturizers, vehicle effects, and photocarcinogenesis,” Journal of Investigative Dermatology, vol. 129, no. 2, pp. 261–262, 2009.
[15]
Y. K. Seo, S. J. Kim, Y. C. Boo, J. H. Baek, S. H. Lee, and J. S. Koh, “Effects of p-coumaric acid on erythema and pigmentation of human skin exposed to ultraviolet radiation,” Clinical and Experimental Dermatology, vol. 36, no. 3, pp. 260–266, 2011.
[16]
J. S. Im, P. Balakrishnan, D. H. Oh et al., “Evaluation of salicylic acid fatty ester prodrugs for UV protection,” Drug Development and Industrial Pharmacy, vol. 37, no. 7, pp. 841–848, 2011.
[17]
E. Merinville, A. J. Byrne, A. V. Rawlings, A. J. Muggleton, and A. C. Laloeuf, “Three clinical studies showing the anti-aging benefits of sodium salicylate in human skin,” Journal of Cosmetic Dermatology, vol. 9, no. 3, pp. 174–184, 2010.
[18]
M. Tasic-Kostov, S. Savic, M. Lukic, S. Tamburic, M. Pavlovic, and G. Vuleta, “Lactobionic acid in a natural alkylpolyglucoside-based vehicle: assessing safety and efficacy aspects in comparison to glycolic acid,” Journal of Cosmetic Dermatology, vol. 9, no. 1, pp. 3–10, 2010.
[19]
T. B. Fitzpatrick, G. Szabo, M. Seiji, and W. C. QuevedoJr, “Biology of the melanin pigmentary system,” in Dermatology in General Medicine, T. B. Fitzpatrick, A. Z. Eisen, K. Wolff, I. M. Freedberg, and K. F. Austen, Eds., pp. 131–163, McGraw-Hill, New York, NY, USA, 1976.
[20]
A. Kornhauser, R. R. Wei, Y. Yamaguchi et al., “The effects of topically applied glycolic acid and salicylic acid on ultraviolet radiation-induced erythema, DNA damage and sunburn cell formation in human skin,” Journal of Dermatological Science, vol. 55, no. 1, pp. 10–17, 2009.
[21]
T. Tadokoro, N. Kobayashi, B. Z. Zmudzka et al., “UV-induced DNA damage and melanin content in human skin differing in racial/ethnic origin,” The FASEB Journal, vol. 17, no. 9, pp. 1177–1179, 2003.
[22]
T. Tadokoro, Y. Yamaguchi, J. Batzer et al., “Mechanisms of skin tanning in different racial/ethnic groups in response to ultraviolet radiation,” Journal of Investigative Dermatology, vol. 124, no. 6, pp. 1326–1332, 2005.
[23]
Y. Yamaguchi, K. Takahashi, B. Z. Zmudzka et al., “Human skin responses to UV radiation: pigment in the upper epidermis protects against DNA damage in the lower epidermis and facilitates apoptosis,” The FASEB Journal, vol. 20, no. 9, pp. 1486–1488, 2006.
[24]
Y. Yamaguchi, S. G. Coelho, B. Z. Zmudzka et al., “Cyclobutane pyrimidine dimer formation and p53 production in human skin after repeated UV irradiation,” Experimental Dermatology, vol. 17, no. 11, pp. 916–924, 2008.
[25]
Commission Internationale de l'Eclairage, “CIE Standard S 007/E-1998: erythema reference action spectrum and standard erythema dose,” CIE S ;007/E-1998:ISO 17166;1999.
[26]
Food and Drug Administration, “Sunscreen drug products for over-the-counter human use; final monograph,” 21 CFR Parts 310, 352, 700, and 740 [Docket No 78N-0038], 1999.
[27]
A. Chardon, I. Cretois, and C. Hourseau, “Skin colour typology and suntanning pathways,” International Journal of Cosmetic Science, vol. 13, pp. 191–208, 1991.
[28]
J. Ferguson, M. Brown, D. Alert et al., “Collaborative development of a sun protection factor test method: a proposed European Standard: COLIPA Task Force 'Sun Protection Measurement', Europe,” International Journal of Cosmetic Science, vol. 18, no. 5, pp. 203–218, 1996.
[29]
G. N. Stamatas, J. Wu, and N. Kollias, “Non-invasive method for quantitative evaluation of exogenous compound deposition on skin,” Journal of Investigative Dermatology, vol. 118, no. 2, pp. 295–302, 2002.
[30]
G. N. Stamatas, B. Z. Zmudzka, N. Kollias, and J. Z. Beer, “Non-invasive measurements of skin pigmentation in situ,” Pigment Cell Research, vol. 17, no. 6, pp. 618–626, 2004.
[31]
G. N. Stamatas, B. Z. Zmudzka, N. Kollias, and J. Z. Beer, “In vivo measurement of skin erythema and pigmentation: new means of implementation of diffuse reflectance spectroscopy with a commercial instrument,” British Journal of Dermatology, vol. 159, no. 3, pp. 683–690, 2008.
[32]
W. Choi, Y. Miyamura, R. Wolber et al., “Regulation of human skin pigmentation in situ by repetitive UV exposure: molecular characterization of responses to UVA and/or UVB,” Journal of Investigative Dermatology, vol. 130, no. 6, pp. 1685–1696, 2010.
[33]
C. L. Tock, L. R. Turner, A. Altiner, et al., “Transcriptional signatures of full-spectrum and non-UVB-spectrum solar irradiation in human skin,” Pigment Cell & Melanoma Research, vol. 24, pp. 972–974, 2011.
[34]
R. Kurata, F. Fujita, K. Oonishi, K. I. Kuriyama, and S. Kawamata, “Inhibition of the CXCR3-mediated pathway suppresses ultraviolet B-induced pigmentation and erythema in skin,” British Journal of Dermatology, vol. 163, no. 3, pp. 593–602, 2010.
[35]
A. Clemmensen, K. E. Andersen, O. Clemmensen et al., “Genome-wide expression analysis of human in vivo irritated epidermis: differential profiles induced by sodium lauryl sulfate and nonanoic acid,” Journal of Investigative Dermatology, vol. 130, no. 9, pp. 2201–2210, 2010.
[36]
M. G. Rubin, “The clinical use of alpha hydroxy acids,” Australasian Journal of Dermatology, vol. 35, no. 1, pp. 29–33, 1994.
[37]
C. M. Ditre, T. D. Griffin, G. F. Murphy et al., “Effects of α-hydroxy acids on photoaged skin: a pilot clinical, histologic, and ultrastructural study,” Journal of the American Academy of Dermatology, vol. 34, no. 2 I, pp. 187–195, 1996.
[38]
J. T. E. Lim and S. N. Tham, “Glycolic acid peels in the treatment of melasma among Asian women,” Dermatologic Surgery, vol. 23, no. 3, pp. 177–179, 1997.
[39]
A. Garcia and J. E. Fulton, “The combination of glycolic acid and hydroquinone or kojic acid for the treatment of melasma and related conditions,” Dermatologic Surgery, vol. 22, no. 5, pp. 443–447, 1996.
[40]
K. E. Sharquie, M. M. Al-Tikreety, and S. A. Al-Mashhadani, “Lactic acid as a new therapeutic peeling agent in melasma,” Dermatologic Surgery, vol. 31, no. 2, pp. 149–154, 2005.
[41]
C. Cotellessa, K. Peris, M. T. Onorati, M. C. Fargnoli, and S. Chimenti, “The use of chemical peelings in the treatment of different cutaneous hyperpigmentations,” Dermatologic Surgery, vol. 25, no. 6, pp. 450–454, 1999.
[42]
L. S. Kakita and N. J. Lowe, “Azelaic acid and glycolic acid combination therapy for facial hyperpigmentation in darker-skinned patients: a clinical comparison with hydroquinone,” Clinical Therapeutics, vol. 20, no. 5, pp. 960–970, 1998.
[43]
R. L. Burns, P. L. Prevost-Blank, M. A. Lawry, T. B. Lawry, D. T. Faria, and D. P. Fivenson, “Glycolic acid peels for postinflammatory hyperpigmentation in black patients: a comparative study,” Dermatologic Surgery, vol. 23, no. 3, pp. 171–175, 1997.
[44]
A. Usuki, A. Ohashi, H. Sato, Y. Ochiai, M. Ichihashi, and Y. Funasaka, “The inhibitory effect of glycolic acid and lactic acid on melanin synthesis in melanoma cells,” Experimental Dermatology, vol. 12, supplement 2, pp. 43–50, 2003.
[45]
T. F. Tsai, P. H. Bowman, S. H. Jee, and H. I. Maibach, “Effects of glycolic acid on light-induced skin pigmentation in Asian and Caucasian subjects,” Journal of the American Academy of Dermatology, vol. 43, no. 2 I, pp. 238–243, 2000.
[46]
P. E. Grimes, B. A. Green, R. H. Wildnauer, and B. L. Edison, “The Use of Polyhydroxy Acids (PHAs) in photoaged skin,” Cutis, vol. 73, no. 2, pp. 3–13, 2004.
[47]
C. Effron, M. E. Briden, and B. A. Green, “Enhancing cosmetic outcomes by combining superficial glycolic acid (α-hydroxy acid) peels with nonablative lasers, intense pulsed light, and trichloroacetic acid peels,” Cutis, vol. 79, no. 1, pp. 4–8, 2007.
