Original article Antioxidant and DNA damage protecting activities of Eulophia nuda Lindl. Vinay Kumar a, * , Melissa Lemos a , Mansi Sharma a , Varsha Shriram b a Department of Biotechnology, Modern College of Arts, Science and Commerce, Pune 411 053, India b Department of Botany, Prof. Ramkrishna More College of Arts, Commerce and Science, Pune 411044, India article info Article history: Received 7 May 2013 Accepted 11 July 2013 Available online 20 August 2013 Keywords: Antioxidants DNA damage protection Fenton’s reagent Lipid-peroxidation Reactive oxygen species abstract Introduction: In recent years, natural antioxidants have seen an unprecedented importance and demand in bio-pharmaceuticals, nutraceuticals besides their use as food additives. Antioxidants act as potential prophylactic and therapeutic agents against various diseases caused by free-radicals. Plants offer tremendous source of antioxidants and are therefore being evaluated for their potentials. Eulophia nuda is an important medicinal plant used by local healers in India; however its antioxidant properties have not yet been investigated. Methods: Aqueous (AqE), methanol (ME), aqueousemethanol (AqME) and acetone (AE) extracts of shade dried tubers were obtained and were concentrated in vacuo. Total phenols, flavonoids, ascorbic acid and carotenoids were estimated from all extracts using standard methods. Antioxidant activities of extracts were determined by total antioxidant activity, FRAP, ABTS, DPPH, and OH radical scavenging assays besides lipid peroxidation inhibition. Extracts were evaluated for protection of Fenton’s reagent induced DNA damage. Results: The results confirmed the plant as a rich source of phenols, flavonoids, vitamin C and carotenoids. Among four extracts, AqME showed highest antioxidant activities as evidenced by maximum scavenging of ABTS (98%), DPPH (87%), and OH radicals (99%) at 1 mg ml 1 concentration and showed maximal inhibition of lipid peroxidation. All extracts protected the DNA from hydroxyl-radical-induced damage. Again, AqME was proved to be best in providing protection to DNA against damage caused by free- radicals. Conclusion: The results provides scientific basis for its traditional usage as natural antioxidant and phyto- therapeutic agent. The plant possesses high amount of phenolic compounds and showed a broad- spectrum antioxidant properties including DNA protection. Copyright Ó 2013, SciBiolMed.Org and Phcog.Net, Published by Reed Elsevier India Pvt. Ltd. All rights reserved. 1. Introduction Oxidative stress, induced by the generation of reactive oxygen species (ROS) consisting of both free radical compounds such as superoxide anions (O 2  ), hydroxyl radicals (  OH), as well as non- free-radical compounds hydrogen peroxide (H 2 O 2 ), organic peroxide (ROOH), ozone (O 3 ) and singlet oxygen ( 1 O 2 ) are consid- ered as major causative factors of many of today’s diseases including diabetes and cardiovascular diseases. 1e3 These ROS are known as exacerbating factors in DNA damage and mutations, cellular injury, oncogenesis (as many mutagens and carcinogens acts through the ROS) and ultimately the aging process. 4,5 Further, ROS are considered to cause cancer and several neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, Down’s syndrome, inflammation, viral infection and various other digestive disorders including ulcer and gastrointestinal disorders. 6,7 Antioxidants are considered to play an imperative role in providing protection against ROS-driven oxidative damage and associated lipid peroxidation, and DNA strand breaking. 3 Even though many antioxidants of synthetic origin are available and used quite frequently, especially in food industry for preservation and prolonging the shelf-lives of food products, however, they are often being associated with quality deterioration, nutritional losses and off-flavor development. 8 Furthermore, available synthetic antioxi- dants have been reported to exhibit toxic and mutagenic effects. 9 On the other hand, their natural counterparts have an edge over them for being less- or non- toxic and hence can serve as potential drug and dietary molecules. Therefore, in recent years the * Corresponding author. Tel.: þ91 20 25634021; fax: þ91 20 25650931. E-mail addresses: vinaymalik123@gmail.com, vinaymalik123@rediffmail.com (V. Kumar). Contents lists available at ScienceDirect Free Radicals and Antioxidants journal homepage: www.elsevier.com/locate/fra 2231-2536/$ e see front matter Copyright Ó 2013, SciBiolMed.Org and Phcog.Net, Published by Reed Elsevier India Pvt. Ltd. All rights reserved. http://dx.doi.org/10.1016/j.fra.2013.07.001 Free Radicals and Antioxidants 3 (2013) 55e60