Vol 13, Issue 3, 2020 Online - 2455-3891 Print - 0974-2441 ANTIOXIDATIVE AND FREE RADICAL SCAVENGING POTENTIALS OF HABENARIA PECTINATA CHARANJIT KAUR 1,2 , RAJESH KUMAR 1,3 , GURVINDER SINGH 3 , CHANDER MOHAN 4 * 1 I. K. Gujral Punjab Technical University, Kapurthala, Punjab, India. 2 Department of Pharmaceutical Chemistry, Khalsa College of Pharmacy, Amritsar, Punjab, India. 3 Department of Pharmaceutical Sciences, Lovely Faculty of Applied Medical Sciences, Lovely Professional University, Phagwara, Punjab, India. 4 Department of Pharmaceutical Chemistry, Rayat Bahra Institute of Pharmacy, Hoshiarpur, Punjab, India. Email: charan_3216@yahoo.in Received: 19 December 2019, Revised and Accepted: 09 January 2020 ABSTRACT Objective: This study was designed to evaluate the antioxidative potential of tubers of Habenaria pectinata. Methods: The tubers of H. pectinata were extracted using hexane, ethyl acetate, methanol, and water as solvents. The anti-oxidant potential of extracts was evaluated using free radical scavenging and reducing power assays. The most active methanolic extract was then fractionated into four fractions using the above-mentioned solvents. Results: The phenol and flavonoid content was found to be maximum in the methanol extracts. All the extracts and fractions showed significant levels of antioxidant activity except hexane extract. Conclusion: The tubers of H. pectinata were found to possess a significant antioxidant potential and can be explored further for isolation and preclinical investigation for the ailment of various diseased states and disorders. Keywords: Habenaria, Antioxidant, 1,1-diphenyl-2-picrylhydrazyl. INTRODUCTION Natural resources have always been a good source of antioxidants. Several epidemiological studies suggest that a high intake of foods rich in natural antioxidants reduces the risk of several debilitating diseased states and disorders. Moreover, these antioxidants also contribute to the preservation of foods and food products. This necessitates the exploration of bioresources for newer and older antioxidants qualitatively as well as quantitatively to meet the demands of the food industry and health management systems [1,2] Habenaria pectinata belongs to the family Orchidaceae; a terrestrial plant found in forests around 1800 m in India, Yunnan, and Nepal [3]. The crushed leaves are reported to treat snake bites and tubers for arthritis in India [4]. Preliminary investigation involving standard phytochemical tests on the prepared extracts revealed the presence of flavonoids and phenols in this plant. Moreover, the closely related species Habenaria intermedia has been reported to be a potential source of antioxidants [5]. Hence, we decided to check the total phenolic and flavonoid compounds quantitatively along with the evaluation of antioxidant properties of various extracts and fractions of H. pectinata connected to the presence of phenols and flavonoids in this plant. METHODS Plant material The tubers of the plant H. pectinata were collected from Shimla and Dhanaulti Regions in August. The plant material was authenticated by Manager (Quality Control and Quality Assurance Department, Herbal Health Research Consortium Pvt. Ltd., established by National Medicinal Plants Board, MINISTRY OF AYUSH; Government of India). Extraction and preliminary fractionation Dried tubers were extracted with four different solvents: Hexane, ethyl acetate, methanol, and water and then methanolic extract (yield 12.5 g) was further fractionated using the above-mentioned solvents to obtain four different fractions (hexane, ethyl acetate, methanol and water). Quantitative phytochemical analysis Estimation of total phenolic compounds The quantitative estimation of phenolic compounds was done using the Folin–Ciocalteu reagent method of Lister and Wilson [6]. A standard curve was prepared using different concentrations of Gallic acid (10–100 µg/ml). The absorbance of all the test samples (extracts and fractions) was measured at 760 nm. Total phenolic content was expressed as mg/g Gallic acid equivalent (GAE) [7]. Estimation of total flavonoid content The flavonoid content in the extract was determined spectrophotometrically by the method of Quettier-Deleu et al. [8]. Rutin was used as the standard to make the calibration curve and the absorbance of the reaction mixture was measured at 430 nm. The flavonoid content was expressed as mg/g rutin equivalent (RE). © 2020 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4. 0/) DOI: http://dx.doi.org/10.22159/ajpcr.2020.v13i3.36663 Research Article Fig. 1: Calibration curve of gallic acid