Food Sci. Biotechnol. 21(6): 1723-1727 (2012) DOI 10.1007/s10068-012-0229-4 Antioxidant and Antimicrobial Activities of Smilax china L. Leaf Extracts Hye-Kyung Seo, Jong-Hwa Lee, Hyun-Su Kim, Chang-Kwon Lee, and Seung-Cheol Lee Received: 22 May 2012 / Revised: 6 July 2012 / Accepted: 6 July 2012 / Published Online: 31 December 2012 © KoSFoST and Springer 2012 Abstract Antioxidant and antimicrobial activities of Smilax china L. leaf extracts obtained with methanol, ethanol, acetone, and water were investigated. Antioxidant activity was evaluated by determining the DPPH radical scavenging activity, ABTS radical scavenging activities, total phenol content (TPC), and reducing power (RP). The highest DPPH, ABTS radical scavenging activity, and RP were found in the ethanol extract, which also showed the highest TPC (105.81±0.48 μg gallic acid equivalents/mL). The antimicrobial activity of all the extracts against foodborne microorganisms was determined by paper disc method. All the extracts inhibited the growth of Listeria monocytogenes, Staphylococcus aureus, and Salmonella Typhimurium, however, no antimicrobial activity was observed against Escherichia coli O157:H7. The results indicated that Smilax china L. possessed antioxidant and antimicrobial substances, and suggested that the ethanol extract can be applied into food and cosmetic industry. Keywords: Smilax china L., leaf, antioxidant activity, antimicrobial activity Introduction The genus Smilax, belongs to the Liliaceae family, contains 350 species, and is widely distributed in the tropical and temperate zones throughout the world, and especially in tropical regions of East Asia, and South and North America (1). Many of them have been used as medicinal herbs in East Asian countries. For example, Smilax china L. is a commonly used in traditional Chinese medicine for treatment of diuretic, rheumatic arthritic, detoxication, lumbago, gout, tumor, and inflammatory diseases (2). Recent pharmacological investigations showed that S. china has anti-inflammatory activity (3-6) and some steroidal saponins isolated from this plant exhibited significant cytotoxicity against several tumor cell lines (7,8). Furthermore, kaempferol-7- O-β-D-glucoside isolated from S. china L. rhizome induces apoptosis on cancer cells (9). S. china L. also exhibits anti-hyperuricemic and nephroprotective activity in hyperuricemic animals (10). Oxidative metabolism is essential for normal biological activities of cell. However, it also accompanies the production of reactive oxygen species (ROS) (11). Oxidative modification of DNA, proteins, lipids, and small cellular molecules by excess of ROS plays a role in a wide range of common diseases such as cardiovascular diseases, neurodegenerative disorders, cancer, and aging. Oxidation also affects food quality. It is a major cause for food deterioration through affecting color, flavor, texture, and nutritional value. Antioxidants are vital substances which possess the ability to reduce oxidative damage caused by ROS (12,13). As the possible carcinogenic effects of synthetic antioxidants, it has been suggested that natural antioxidants are more safe and healthy than synthetic antioxidants which used in food (14,15). Smilax china L. is called as ‘manggae’ in southern region of Korea, and manggaedduck of Uiryong-gun is Hye-Kyung Seo, Chang-Kwon Lee, Seung-Cheol Lee () Department of Food Science and Biotechnology, Kyungnam University, Changwon, Gyeongnam 631-701, Korea Tel: +82-55-249-2684; Fax: +82-55-249-2995 E-mail: sclee@kyungnam.ac.kr Jong-Hwa Lee Department of Food Science and Biotechnology, Andong National University, Andong, Gyeongbuk 760-749, Korea Hyun-Su Kim Department of Pharmaceutical Engineering, International University of Korea, Jinju, Gyeongnam 660-759, Korea Hye-Kyung Seo, Chang-Kwon Lee Monggo Foods Co., Ltd., Changwon, Gyeongnam 641-465, Korea RESEARCH ARTICLE