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J. Cosmet. Sci., 65, 69–79 (March/April 2014) 69 Antioxidant, antimelanogenic, and skin-protective effect of sesamol MONTRA SRISAYAM, NATTHIDA WEERAPREEYAKUL, SAHAPAT BARUSRUX, and KWANJAI KANOKMEDHAKUL, Graduate School, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, 40002, Thailand (M.S.), Center for Research and Development of Herbal Health Products, Khon Kaen University, Khon Kaen, 40002, Thailand (N.W.), Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, 40002, Thailand (N.W.), Centre for Research and Development of Medical Diagnostic Laboratories, Khon Kaen University, Khon Kaen, 40002, Thailand (S.B.), Faculty of Associate Medical Sciences, Khon Kaen University, Khon Kaen, 40002, Thailand (S.B.), Faculty of Sciences, Khon Kaen University, Khon Kaen, 40002, Thailand (K.K.) Accepted for publication February 18, 2014. Synopsis Sesame contains high nutritional value and important bioactive lignans which are good for health-promoting effects including sesamol. Sesamol is found in trace amounts in sesame. The biological action from the trace amounts of sesamol found might indicate its effi cacy. This paper presents a systematic study of the antimela- nogenic and skin-protective effects (antioxidant) of sesamol and positive compounds. The results showed that sesamol had the most scavenging 2,2-Diphenyl-1-picrylhydrazyl hydrate (DPPH·) radical with an IC50 value 14.48 μM. The antioxidant power (Ferric reducing antioxidant power value) of sesamol at a concentration of 0.1129 μM was 189.88 ± 17.56 μM FeSO4. Sesamol inhibited lipid peroxidation with an IC50 value of 6.15 ± 0.2 μM. Moreover, sesamol possessed a whitening effect by inhibition of mushroom tyrosinase at an IC50 value of 1.6 μM and an inhibition of cellular tyrosinase with 23.55 ± 8.25% inhibition at a concentra- tion of 217.2 μM. Sesamol exhibited high antioxidant and anti-tyrosinase activity compared to the positive control, kojic acid and β-arbutin. Sesamol from edible sesame seed could therefore have an alternative cosme- ceutical purpose. INTRODUCTION Sesame is rich in proteins, dietary fi ber, micronutrients, and bioactive phytochemicals. The seeds and their pressed oil contain important bioactive lignans sesamin, sesamolin, and sesamol. The presence of sesame lignans were reported to play a pivotal role in Address all correspondence to Natthida Weerapreeyakul at natthida@kku.ac.th.