Original Article ANTIOXIDANT ACTIVITY AND ANTIBACTERIAL SCREENING OF TUBERS OF AMORPHOPHALLUS KONKANENSIS AND AMORPHOPHALLUS BULBIFER (ARACEAE) CHIDANAND C. SHETE 1 , SURYAKANT S. WADKAR 1 , NIKHIL B. GAIKWAD 1 , KUMAR S. PATIL 2* 1 Department of Botany, Shivaji University, Vidyanagar, Kolhapur, 416004, (MS) India, 2 *Department of Botany, Smt. K. W. College, Sangli 416416, (MS) India Email: kspatilbiotech@yahoo.com Received: 24 Sep 2014 Revised and Accepted: 25 Oct 2014 ABSTRACT Objective: Antioxidant activity (AOA) and antibacterial screening of tubers of unexplored Amorphophallus konkanensis Hett., Yadav & Patil (AKT) and Amorphophallus bulbifer (Roxb.) Bl. (ABT). Methods: Antioxidant activity was evaluated by using ferric reducing antioxidant power (FRAP), 1 1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl (OH•) radical, nitric oxide (NO∙) radical scavenging activities. Phenolics were determined by total phenolic content (TPC) assay. Antibacterial screening of different solvent extracts of tubers was tested against Gram positive and Gram negative bacterial strains by using the agar diffusion method. HPLC analysis was carried out for active phenolic compounds. Results: Tubers were extracted with three different solvents (ethanol, acetone and water). Acetone extracts of AKT and ABT exhibited the highest phenolic content 29.37±0.83 and 20.62±1.04 mg GAE/g. The AKT and ABT acetone extracts possesses highest free radical scavenging activity towards FRAP (0.632 & 0.586 O. D), DPPH (85.78% & 82.68%), hydroxyl (OH∙) radical (82.43% & 80.26%), nitric oxide (NO∙) radical (81.34% & 80.8%). The phenolic compounds tannic acid, gallic acid, quercetin, p-coumaric acid, catechin were identified by the HPLC method in acetone extracts. Among the different extracts, acetone extract of both the species of Amorphophallus showed significant antibacterial activity against all Gram positive and Gram negative bacterial strains tested. Conclusion: The results indicated that AKT and ABT can be considered as good sources of natural antioxidant for medicinal, commercial, nutraceutical and functional food applications. Antibacterial efficacy shown by these plants provides a scientific basis for their traditional uses in remedies. Keywords: Antioxidant, Antibacterial, Phenolics, HPLC, Amorphophallus konkanensis, Amorphophallus bulbifer. INTRODUCTION A free radical is a molecule with one or more unpaired electrons in the outer orbital. These free electrons are referred to as oxidizing agents [1]. Many of the free radicals such as superoxide radical (O2• – Antioxidants are able to retard, delay or prevent oxidation process [3]. The potential of antioxidant constituents of plant materials for the maintenance of health and protection from coronary heart disease and cancer is also raising interest among scientists and food manufacturers as consumers move toward functional foods with specific health effects [4]. Number of plant species possesses natural antioxidants with high antioxidant activity and investigations on these were initiated based on their uses in traditional medicines [5]. ), hydroxyl radical (OH•), peroxyl radical (ROO•) and nitric oxide radical (NO•) attack biological molecules, such as lipids, proteins, enzymes, DNA and RNA, leading to cell or tissue injury associated with aging, atherosclerosis, carcinogenesis [2]. An antimicrobial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi or protozoan. A wide range of natural compounds are used as antimicrobials [6]. Plants have an almost limitless ability to synthesize aromatic substances, most of which are phenols or their oxygen substituted derivatives. Most of which are secondary metabolites, of which at least 12,000 have been isolated. A number were estimated to be less than 10% of the total. Such a secondary metabolites plays a very important role in plant defense mechanism [7]. The World Health Organization estimated that 80% of the population in developing countries still relies on traditional medicines, mostly plant drugs for their primary health care needs. Although hundreds of plant species have been tested for antimicrobial properties, the vast majority of have not been adequately evaluated [8]. Hence, there is an urgent need to study the screening of antimicrobial properties of herbs, which will be helpful in the treatment of several diseases caused by microorganisms [9, 10]. Amorphophallus species are mainly used as a vegetable and as an ingredient in ayurvedic preparations [11]. The tuberous roots of the species of Amorphophallus campanulatus Bl. are used traditionally for the treatment of piles, abdominal pain, tumors, enlargement of spleen, asthma and rheumatism [12]. The tuberous roots of the plant also have tonic, stomachic and appetizer properties [13]. The tuber contains flavonoids, phenols, coumarins, terpenoids, sterols, tannins, steroids, alkaloids and sugars like glucose, galactose and rhamnose [14, 15]. The purpose of this study was to evaluate Amorphophallus konkanensis and Amorphophallus bulbifer as new potential sources of phenolic compounds having the natural antioxidants and antibacterial activity. MATERIAL AND METHODS Plant material and sample preparation Fresh tubers of Amorphophallus konkanensis Hett.,Yadav & Patil (AKT) and Amorphophallus bulbifer (Roxb.) Bl. (ABT) (Family: Araceae) were collected from Ratnagiri and Amboli in Western Ghats of Maharashtra, India respectively. The tubers were cleaned, chopped and kept in hot air oven at 40 0 C for 48h for drying. The dried AKT and ABT were made to a fine powder using mortar pestle. Tubers were extracted using solvents, acetone, ethanol and water at solvent to powder ratio of 1: 10. Weighed amount of each sample was extracted in known volume of the solvent for 24 h with shaking on a rotary shaker. Each extracted material was filtered through Whatman filter paper No. 1. These extracts were again dried and concentrated by evaporating the solvent completely in a water bath at the range of boiling points of solvents. The dried extracts were re suspended in respective solvents [16] and stored at 4°C. These extracts used to test the total phenolic content (TPC), Ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical, (OH∙) radical, (NO∙) radical. International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 6, Issue 11, 2014 Innovare Academic Sciences