The purpose of this study was to evaluate the antioxidant and hepatocyte protective effects of guava (Psidium guajava L.) leaves cultivated in Korea. The contents of the total polyphenol of the extract was 271.57 mg gallic acid equivalent (GAE)/ g residue. Antioxidant activities of leaf extract were evaluated by examining the free radical scavenging ability. 2,2'-azinobis-( 3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and α-α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging activities of the extract were 1133.23 mg trolox equivalent antioxidant capacity (TEAC)/g residue and 721.68 mg TEAC/g residue, respectively. The hepatocyte protective effect of guava leaf extract was examined in HepG2 cells. Against tert-butyl hydroperoxide (TBHP), the viability of HepG2 cells were increased by the treatment of leaf extract. In addition, guava leaf extract led to the inhibition of reactive oxygen species (ROS) generated in HepG2 cells. The leaf extract increased the activity of glutathione (GSH), glutathione reductase (GR), and glutathione peroxidase (GPx) against oxidative stress. These results suggested that guava leaves might be regarded as a potential source natural antioxidant and a hepatoprotective material.

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• 천원영(경성대학교 식품생명공학과) | Wonyoung Cheon (Dept. of Food Science and Biotechnology, Kyungsung University)
• 서동연(국립농산물품질관리원 시험연구소 안전성분석과) | Dongyeon Seo (Safety Analysis Div., Experiment Research Institute, National Agricultural Products Quality Management Service)
• 김영화(경성대학교 식품응용공학부) | Younghwa Kim (School of Food Biotechnology and Nutrition, Kyungsung University) Corresponding author