Comparative study on antiproliferation properties and cellular antioxidant activities of commonly consumed food legumes against nine human cancer cell lines Baojun Xu a , Sam K.C. Chang b,⇑ a Food Science and Technology Program, Beijing Normal University–Hong Kong Baptist University United International College, Zhuhai 519085, China b Department of Cereal and Food Sciences, North Dakota State University, Dept. 2710, Fargo, ND 58105-6050, United States article info Article history: Received 7 November 2011 Received in revised form 29 January 2012 Accepted 29 February 2012 Available online 8 March 2012 Keywords: Adzuki bean Mung bean Black soybean Lentil Phytochemicals Antiproliferation Cellular antioxidative activity Cancer cells abstract The aims of this work were to compare health promoting effects of commonly consumed food legumes in terms of cancer cell proliferation inhibitory effects and cellular antioxidant activities (CAA). The CAA was evaluated by fluorescence microplate reader based on in vitro animal cell cultivation. Antiproliferative properties were assayed by MTT method using in vitro cell culture system. Phytochemicals (including total phenolic, procyanidin, saponin and phytic acid) and chemical antioxidant activities (including DPPH free radical scavenging activity, oxygen radical absorbing capacity, peroxyl radical scavenging capacity (PRSC)) were also determined for comparison purposes. The results showed that different types of legumes possessed considerable variations in their phytochemicals, as well as chemical and cellular anti- oxidant activities. Adzuki bean exhibited the strongest antiproliferative properties in a dose-dependent manner against all digestive system cancer cell lines (CAL27, AGS, HepG2, SW480 and Caco-2), ovary can- cer cell SK-OV-3 and breast cancer cell MCF-7 among all legumes tested. Black soybean exhibited the highest saponin, phytic acid content, PRSC values, and the strongest CAA values. These results indicate that commonly consumed food legumes may serve as an excellent dietary source of natural antioxidants for health promotion and cancer prevention. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction A large range of species of grain legumes are cultivated and con- sumed throughout the world. Experimental, epidemiological and clinical studies show correlations between the consumption of food legumes and decreasing incidence of cancers (Mathers, 2002; Adebamowo et al., 2005). Epidemiological studies have found links between the low incidence of cancer and consumption of beans. For example, epidemiological data from 41 countries revealed that countries with the greatest consumption of beans had the lowest death rates due to breast, prostate, and colon cancer (Bawadi, Bansode, Trappy, Truax, & Losso, 2005; Bobe et al., 2008; Correa, 1981; Geil & Anderson, 1994; Hangen & Bennink, 2003; Hughes, Ganthavorn, & Wilson-Sanders, 1997; Shi et al., 2004). Some case- control studies have provided evidence of protection by food legumes against cancer of the colon and rectum (Franceschi, 1999) and prostate (Jain, Hislop, Howe, & Ghadirian, 1999). Preclinical studies have also shown that feeding black or navy beans to laboratory animals reduced both the incidence and number of colon tumors by 50% (Hangen & Bennink, 2003). The World Cancer Relief Fund/American Institute for Cancer Research Committee recognised the potential of food legumes consumption to decrease cancer risk and emphasised the need for additional research in this area (World Cancer Research Fund, 1997). It is recognised that the health effects of food are generally asso- ciated with antioxidant activities or free radical scavenging proper- ties of phenolic components existed in food. The antioxidant activities (determined by in vitro chemical assays) and phenolic compounds of food legumes have been extensively reported in numerous literatures (Amarowicz, Troszynska, Barylko-Pikielna, & Shahidi, 2004; Beninger & Hosfield, 2003; Cardador-Martinez, Loacra-Pina, & Oomah, 2002; Madhujith, Naczk, & Shahidi, 2004), as well as our earlier communications (Xu & Chang, 2008b, 2010; Xu, Yuan, & Chang, 2007). However, there are various food legumes available in the market for human consumption, such as green pea, yellow pea, chickpea, lentil, yellow soybean, black soybean, pinto bean, black bean, small red bean, red kidney bean, mung bean, adzuki bean, and black eyed pea. The diversity of phenotypes of food legumes indicates that complex phytochemical profiles and health benefits may differ in various legume classes. On the other hand, in recent years, most of the so-called anti-nutrients (such as 0308-8146/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodchem.2012.02.212 Abbreviations: CAA, cellular antioxidant activity; DDI, dose-dependent inhibi- tion; DPPH, 2-diphenyl-1-picryhydrazyl radical; FRAP, ferric reducing antioxidant power; NDD, non-dose-dependent; ORAC, oxygen radical absorbing capacity; PAC, procyanidin content; PRSC, peroxyl radical scavenging capacity; TPC, total phenolic content; TSC, total saponin content. ⇑ Corresponding author. Tel.: +1 701 231 7485; fax: +1 701 231 6536. E-mail address: kow.chang@ndsu.edu (S.K.C. Chang). Food Chemistry 134 (2012) 1287–1296 Contents lists available at SciVerse ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem