J. E. Hayes, P. Allen, N. Brunton, M. N. O’Grady and J. P. Kerry, “Phenolic Composition and in Vitro Antioxidant Capacity of Four Commercial Phytochemical Products: Olive Leaf Extract (Olea europaea), Lutein, Sesamol and Ellagic Acid,” Food Chemistry, Vol. 126, No, 3, 2011, pp. 948-955. doi:10.1016/j.foodchem.2010.11.092

has been cited by the following article:

• TITLE: Antioxidant and Anti-Tyrosinase Activity from Olea Leaf Extract Depended on Seasonal Variations and Chromagraphy Treatment

  AUTHORS: Dao-Mao Yang, Ming-An Ouyang

  KEYWORDS: Olive Leaf Extract; Antioxidant Activity; Tyrosinase Inhibitory Activity; Non-CompetitiveCompetition; Chromagraphy Treatment

  JOURNAL NAME: International Journal of Organic Chemistry, Vol.2 No.4, December 28, 2012

  ABSTRACT: In the present study, olive leaf extract, harvested from four seasons, extracted with solvent (methanol and water), was treated by D101 and Sephadex LH-20, and divided into 10 fractions by TLC detection. The antioxidant activity was evaluated using DPPH, superoxide anion scavenging and reducing power assays. Tyrosinase inhibitory activity was also performed with L-DOPA as substrate. On extraction method, there is no significant difference in methanol and water. Among 12 months, autumn showed the best harvest time in whole. OLE showed 90% tyrosinase inhibitory activity and inhibition type was non-competitive competition. By chromagraphy treatment, the ingredients of polysacchmaride and protein showed high bioactivity towards antioxidant and anti-tyrosinase activity, the rest part showed different extent of activity and prove some effect by chromatography treatment indirectly. OLE might be a valuable bioactive source and can be applicable in both the cosmetic and medical use.