Original Article Antioxidant activity of Potentilla fulgens: An alpine plant of western Himalaya § Vikas Jaitak a , Kapil Sharma b , Kalpana Kalia a , Neeraj Kumar a , H.P.Singh b , V.K. Kaul a, *, Bikram Singh a a Natural Plant Products Division, Institute of Himalayan Bioresource Technology, P. Bag No. 6, Palampur (H.P.), 176061, India b Hill Area Tea Science Division, Institute of Himalayan Bioresource Technology, P. Bag No. 6, Palampur (H.P.), 176061, India 1. Introduction Reactive oxygen species (ROS) are involved in an organism’s vital activities including phagocytosis, regulation of cell prolifera- tion, intracellular signalling, synthesis of biologically active compounds and ATP. With an insufficiency of the antioxidant protective system or under an intense influence of radical- initiating factors (ionizing radiation, ultraviolet radiation, xeno- biotics, mineral dust), ROS are overproduced and oxidative stress develops. In vivo or in vitro, oxidative stress may cause various problems associated with degenerative aging diseases, such as arteriosclerosis and cancer (Halliwell et al., 1992). Free radicals play an important role in some pathogenesis of serious diseases, such as neurodegenerative disorders, atherosclerosis, cataracts, diabetes and inflammation (Aruoma, 1998). Oxidation processes caused by reactive oxygen species are a major cause of deteriora- tion of various food products, i.e. significant changes do occur in flavour, colour, and texture, and finally lead to loss of nutritive value or complete spoilage (Miliauskas et al., 2004). Compounds that can scavenge free radicals have great potential in ameliorating different diseases (Kirakosyan et al., 2003). Antioxidants can influence the oxidation process through simple or complex mechanisms, including prevention of chain initiation, binding of translational metal ion catalysts, decomposition of peroxides, prevention of continued hydrogen abstraction, and radical scavenging (Ames et al., 1993; Hatano et al., 1989; Torel et al., 1986). Antioxidants play an important role in preventing or alleviating chronic diseases by reducing the oxidative damage to cellular components caused by reactive oxygen species (Ceriello, 2003). The use of synthetic oxidants in food products is under strict regulation owing to uncertainty about their safety (Verhagen et al., 1991; IARC, 1987). Hence there is growing interest in natural polyphenolic antioxidants, present in medicinal and dietary plants that help attenuate oxidative damage (Rice-Evans et al., 1997; Silva et al., 2005). These natural antioxidants not only protect food lipids from oxidation, but also provide health benefits associated with preventing damage due to biological degeneration (Hu and Kitts, 2005; Shahidi and Wanasusdara, 1992). The nutraceutical value Journal of Food Composition and Analysis 23 (2010) 142–147 ARTICLE INFO Article history: Received 21 August 2008 Received in revised form 11 February 2009 Accepted 21 February 2009 Keywords: Potentilla fulgens Bajardanti Phenolics Biflavanoid Antioxidant activity ABTS DPPH FRAP TEAC Food analysis Food composition ABSTRACT Antioxidant activities of the methanol extract, fractions and isolated compounds from the roots of Potentilla fulgens Lodd. were evaluated by three in vitro experiments, namely, ABTS, DPPH, and FRAP assays. PF-2 was characterized as a new biflavanoid and designated as Potifulgene on the basis of NMR and mass spectrum, whereas PF-1 was identified as epicatechin. The activities of aqueous methanolic extract and fractions could be correlated with their respective total phenolic content and compared with standard natural antioxidants such as quercetin, vitamin C and pyrogallol. The root powder of the plant was extracted with methanol/water (80:20) by cold extraction and its extract was further partitioned with ethyl acetate, butanol and water fractions. Among the three fractions (ethyl acetate, butanol and water fraction) and the total aqueous methanolic extract, the butanol fraction exhibited good scavenging response measured in terms of TEAC (mM Trolox equivalent/mg extract). The butanol fraction was found to possess strong antioxidant activity (2.54  0.69, 2.41  0.53, 3.57  0.05 mM Trolox equivalent/mg extract) with ABTS, DPPH and FRAP assays, respectively. The chemical composition of extracts, studied in terms of total polyphenol content (TPC), was found in the range of 20.61  0.38 to 33.28  0.11 mg/g gallic acid equivalent. A significant correlation was observed between total polyphenolics and antioxidant activity, indicating participation of phenolics in antioxidant activities of extract and fractions. The antioxidant activity of new biflavanoid (Potifulgene) was found to be higher, i.e. 6.85  0.38, 4.24  0.41, 5.35  0.53 than that of epicatechin, 2.13  0.05, 1.50  0.02, 1.57  0.03 with ABTS, DPPH and FRAP assays. ß 2009 Elsevier Inc. All rights reserved. § IHBT Communication No. 0851. * Corresponding author. Tel.: +91 1894 230426; fax: +91 1894 230433. E-mail address: vkaul2002@yahoo.co.in (V.K. Kaul). Contents lists available at ScienceDirect Journal of Food Composition and Analysis journal homepage: www.elsevier.com/locate/jfca 0889-1575/$ – see front matter ß 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.jfca.2009.02.013