title: Tannase-converted green tea catechins and their anti-wrinkle activity in humans.
abstract: BACKGROUND
  This study was performed to investigate the anti-wrinkle effects of topical applications of green tea extract with high antioxidant activity by tannase treatment. Increases in gallic acid (GA), (-)-epigallocatechin (EGC), and (-)-epicatechin (EC) were observed in the green tea extract after tannase treatment.
  
  
  OBJECTIVE
  This study was performed to investigate the anti-wrinkle effects of topical applications of green tea extract exhibiting high antioxidant activity after tannase treatment.
  
  
  METHODS
  Subjects, randomly divided into two groups, received the application of either tannase-converted green tea extract (TGE) or normal green tea extract (NGE) on their crow's feet for 8 weeks. The anti-wrinkle effects were evaluated with two methods: (i) self-assessment; and (ii) average roughness of skin surface (R(a), R(z), and R(t) value) using skin replica and Skin-Visiometer SV 600.
  
  
  RESULTS
  The scavenging abilities of TGE against radicals were significantly higher compared to NGE. The evaluation of skin wrinkle index values after 8 weeks of treatment showed that reductions of R(a), R(z), and R(t) values in the TGE group were significantly greater than in the NGE group, which indicated that tannase treatment improved the anti-wrinkle effects of green tea extract. According to the overall ratings for wrinkle treatment by applying the formulations, most of the TGE group (63.60%) reported marked or moderate improvement in wrinkles compared with only 36.30% of the NGE group.
  
  
  CONCLUSIONS
  Tannase treatment can improve the antioxidant activity of green tea extract, conferring anti-wrinkle activities. These results suggest that TGE may have beneficial properties as an anti-wrinkle agent.
authors.affiliation: Department of Food and Nutrition, Korea University, Seoul, Korea.
authors.forename: Yang-Hee
authors.initials: YH
authors.lastname: Hong
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Jung
authors.forename: Kwang-Soon
authors.initials: KS
authors.lastname: Shin
authors.forename: Kwang-Won
authors.initials: KW
authors.lastname: Yu
authors.forename: Un Jae
authors.initials: UJ
authors.lastname: Chang
authors.forename: Hyung Joo
authors.initials: HJ
authors.lastname: Suh
mesh_terms: D000328:Adult; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry; D002392:Catechin / Q000031:analogs & derivatives* / Q000032:analysis / Q000494:pharmacology*; D059026:Diagnostic Self Evaluation; D005145:Face; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005707:Gallic Acid / Q000032:analysis / Q000494:pharmacology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008875:Middle Aged; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D015595:Skin Aging / Q000187:drug effects* / Q000473:pathology; D013662:Tea
chemical_list: D016166:Free Radical Scavengers; D010936:Plant Extracts; D013662:Tea; D005707:Gallic Acid; D002392:Catechin; D002265:Carboxylic Ester Hydrolases; C022711:tannase; C057580:gallocatechol