JOURNAL OF COSMETIC SCIENCE 78 been suggested that the cellular tyrosinase inhibition of β-arbutin is due to the intracel- lular conversion of arbutin to hydroquinone via the hydrolysis reaction by bacteria on the skin of humans (33). It is evidenced that the glycosidic linkage of arbutin structure could be cleaved in the cellular assay resulting in the tyrosinase inhibitory activity (34). Moreover, previous study reported that α-arbutin, which is the other isomer form, was also found to be active based on cell-based assay (35). β-Arbutin was reported to possess lesser tyrosinase inhibitory effect than α-arbutin (35). Our study found that β-arbutin exhibited low tyrosinase inhibitory effect which is in agreement with this report. CONCLUSIONS Evidence clearly shows that sesamol possesses high antioxidant properties and anti- tyrosinase activity. Importantly, sesamol was less cytotoxic in the human melanoma cell line (SK-MEL2). This study illustrates that sesamol—a lignan from edible sesame— could be used for cosmeceutical purposes. The molecular mechanisms underlying the antimelanogenic effect in vitro and in vivo and the safety of sesamol in vivo need clarifi cation. ACKNOWLEDGMENTS MS is grateful to the Pibulsongkram Rajabhat University, Thailand, for a PhD scholar- ship and to Graduate school for the fi nancial support of dissertation project (54212107). In fi scal year 2011 (542800) and 2012 (552900), Khon Kaen University Research Fund- ing provided fi nancial support for this project. The authors thank Mr. Bryan Roderick Hamman and Mrs. Janice Loewen-Hamman for assistance with the English-language presentation of the manuscript. REFERENCES (1) S. H. Park, S. N. Ryu, Y. Bu, H. Kim, J. E. Simon, and K. S. Kim, Antioxidant components as potential neuroprotective agents in sesame (Sesamum indicum L.), Food Rev. Int., 26, 103–121 (2010). (2) J. Lee and E. Choe, Extraction of lignan compounds from roasted sesame oil and their effects on the autoxidation of methyl linoleate, J. Food Sci., 71, 430–436 (2006). (3) P. J. Kanu, J. Z. Bahsoon, J. B. Kanu, and J. B. Kandeh, Nutraceutical importance of sesame seed and oil: a review of the contribution of their lignans, Sierra Leone J. Biomed. Res., 2, 4–16 (2010). (4) A. S. Rao, K. S. Rashmi, A. K. Nayanatara, A. Kismat, D. Poojary, and S. R. Pai, Effect of antibacterial and antifungal activities of Sesamum indicum, WJPR, 2, 1676–1680 (2013). (5) S. Periasamy, D.-Z. Hsu, S.-Y. Chen, S.-S. Yang, V. R. M. Chandrasekaran, and M.-Y. Liu, Therapeutic sesamol attenuates monocrotaline-induced sinusoidal obstruction syndrome in rats by inhibiting matrix metalloproteinase-9, Cell Cell Biochem. Biophys., 61, 327–336 (2011). (6) P. Y. Chu, S. P. Chien, D. Z. Hsu, and M. Y. Liu, Protective effect of sesamol on the pulmonary infl am- matory response and lung injury in endotoxemic rats, Food Chem. Toxicol., 48, 1821–1826 (2010). (7) S. Ramachandran, N. Rajendra Prasad, and S. Karthikeyan, Sesamol inhibits UVB-induced ROS gen- eration and subsequent oxidative damage in cultured human skin dermal fi broblasts, Arch. Dermatol. Res., 302, 733–744 (2010). (8) S. Pillai, C. Oresajo, and J. Hayward, Ultraviolet radiation and skin aging: roles of reactive oxygen spe- cies, infl ammation and protease activation, and strategies for prevention of infl ammation-induced ma- trix degradation – a review, Int. J. Cosmet. Sci., 27, 17–34 (2005). (9) A. K. Gupta, M. D. Gover, K. Nouri, and S. Talyor, The treatment of melasma: A review of clinical trials, J. Am. Acad. Dermatol., 55, 1048–1065 (2006). (10) V. M. Sheth and A. G. Pandya, Melasma: a comprehensive update: part I, J. Am. Acad. Dermatol., 65, 689–697 (2011).

WHITENING AND ANTIAGING EFFECT OF SESAMOL 79 (11) J. Viyoch, I. Tengamnuay, K. Phetdee, P. Tuntijarukor, and N. Waranuch, Effects of trans-4- (aminomethyl) cyclohexanecarboxylic acid/potassium azeloyl diglycinate/niacinamide topical emulsion in Thai adults with melasma: a single-center, randomized, double-blind, controlled study, Curr. Ther. Res., 71, 345–359 (2010). (12) S. H. Hamed, P. Sriwiriyanont, M. A. deLong, M. O. Visscher, R. R. Wickett, and R. E. Boissy, Comparative effi cacy and safety of deoxyarbutin, a new tyrosinase-inhibiting agent. J. Cosmet. Sci., 57, 291–308 (2006). (13) J. M. Gillbro and M. J. Olsson, The melanogenesis and mechanisms of skin-lightening agents – existing and new approaches, Int. J. Cosmet. Sci., 33, 210–221 (2011). (14) D. McGregor, Hydroquinone: an evaluation of the human risks from its carcinogenic and mutagenic properties, Crit. Rev. Toxicol., 37, 887–914 (2007). (15) L. Luo, L. Jiang, C. Geng, J. Cao, and L. Zhong, Hydroquinone-induced genotoxicity and oxidative DNA damage in HepG2 cells, Chem. Biol. Interact., 173, 1–8 (2008). (16) K. Sapkota, S. E. Park, J. E. Kim, S. Kim, H. S. Choi, H. S. Chun, and S. J. Kim, Anti-oxidant and anti- melanogenic properties of chestnut fl ower extract, Biosci. Biotechnol. Biochem., 74, 1527–1533 (2010). (17) I. F. Benzie and J. J Strain, The ferric reducing ability of plasma (FRAP) as a measure of “anti-oxidant power”: the FRAP assay. Anal. Biochem., 239, 70–76 (1996). (18) J. W. Bae and M. H. Lee, Effect and putative mechanism of action of ginseng on the formation of gly- cated hemoglobin in vitro, J. Ethnopharm., 91, 137–140 (2004). (19) S. Momtaz, B. M. Mapunya, P.J. Houghton, C. Edgerly, A. Hussein, S. Naidoo, and N. Lall, Tyrosinase inhibition by extracts and constituents of Sideroxylon inerme L. stem bark, used in South Africa for skin lightening. J. Ethnopharm., 119, 507–512 (2008). (20) G. Fotakis and J. A. Timbrell, In vitro cytotoxicity assays: comparison of LDH, neutral red, MTT and protein assay in hepatoma cell lines following exposure to cadmium chloride, Toxicol. Lett., 160, 171–177 (2006). (21) G. A. Repetto, A. del Peso, and J. L. Zurita, Neutral red uptake assay for the estimation of cell viability/ cytotoxicity, Nat. Protoc., 3, 1125–1131 (2008). (22) B. Halliwell, Anti-oxidant defence mechanisms: From the beginning to the end (of the beginning). Free Radic. Res., 31, 261–272 (1999). (23) Á. Sánchez-Ferrer, J. Neptuno Rodríguez-López, F. García-Cánovas, and F. García-Carmona, Tyrosinase: A comprehensive review of its mechanism. Biochim. Biophys. Acta Protein Struct. Mol. Enzymol., 1247, 1–11 (1995). (24) K. P. Suja, A. Jayalekshmy, and C. Arumughan, Free radical scavenging behavior of anti-oxidant com- pounds of sesame (Sesamum indicum L.) in DPPH• system, J. Agri. Food Chem., 52, 912-915 (2004). (25) J. Hayes, P. Allen, N. Brunton, M. O’Grady, and J. Kerry, Phenolic composition and in vitro anti- oxidant capacity of four commercial phytochemical products: Olive leaf extract (Olea europaea L.), lutein, sesamol and ellagic acid. Food Chem., 126, 948–955 (2011). (26) B. S. Wang, L. W. Chang, W. J. Yen, and P. D. Duh, Antioxidative effect of sesame coat on LDL oxida- tion and oxidative stress in macrophages, Food Chem., 102, 351–360 (2007). (27) X. Chen and D. U. Ahn, Anti-oxidant activities of six natural phenolics against lipid oxidation induced by Fe2+ or ultraviolet light, J. Am. Oil Chem. Soc., 75, 1717–1721 (1998). (28) M. Brenner and V. J. Hearing, The protective role of melanin against UV damage in human skin, Pho- tochem. Photobiol., 84, 539–549 (2008). (29) H. M. Chiang, T. J. Lin, C. Y. Chiu, C. W. Chang, K. C. Hsu, P. C. Fan, and K. C. Wen, Coffea arabica extract and its constituents prevent photoaging by suppressing MMPs expression and MAP kinase pathway, Food Chem. Toxicol., 49, 309–318 (2011). (30) G. Kumar and R. S. Yadav, EMS induced genomic disorders in sesame (Sesamum indicum L.), J. Biol. -Plant Biol., 55, 97–104 (2010). (31) C. M. Kumar, U. V. Sathisha, S. Dharmesh, A. G. Rao, and S. A. Singh, Interaction of sesamol (3,4 methylenedioxyphenol) with tyrosinase and its effect on melanin synthesis, Biochimie, 93, 562–569 (2011). (32) R. E. Boissy, M. Visscher, and M. A. DeLong, DeoxyArbutin: a novel reversible tyrosinase inhibitor with effective in vivo skin lightening potency, Exp. Dermatol., 14, 601–608 (2005). (33) S. H. Bang, S. J. Han, and D. H. Kim, Hydrolysis of arbutin to hydroquinone by human skin bacteria and its effect on anti-oxidant activity, J. Cosmet. Dermatol., 7, 189–193 (2008). (34) J. P. Ebanks, R. R. Wickett, and R. E. Boissy, Mechanisms regulating skin pigmentation: the rise and fall of complexion coloration, Int. J. Mol. Sci., 10, 4066–4087 (2009). (35) M. Funayama, H. Arakawa, R. Yamamoto, T. Nishino, T. Shin, and S. Murao, Effects of alpha- and beta- arbutin on activity of tyrosinases from mushroom and mouse melanoma, Biosci. Biotechnol. Biochem., 59, 143–144 (1995).