Vol 12, Issue 6, 2019 Online - 2455-3891 Print - 0974-2441 ISOLATION AND IN VITRO ANTIOXIDANT ACTIVITY OF FLAVONOID FROM LINDERNIA CRUSTACEA (L) F. MUELL SMRITI REKHA CHANDA DAS 1 *, ABDUL BAQUEE AHMED 1 , DIBYENDU SHIL 1 , INDRANIL CHANDA 2 1 Department of Pharmacy, Girijananda Chowdhury Institute of Pharmaceutical Science, Guwahati, Assam, India. 2 Department of Examinations, Assam Science and Technology University, Guwahati, Assam, India. Email: das_smritirekha@rediffmail.com Received: 02 April 2019, Revised and Accepted: 07 May 2019 ABSTRACT Objective: The objective of the study was to investigate the antioxidant property of different extracts of Lindernia crustacea (L) F. Muell and isolate flavonoid from the potent extract and characterize it. Methods: Isolation was carried out by flash chromatography using Toluene:acetic acid (4:1) as eluent. The isolated compound was characterized using spectroscopic methods. 2, 2′- diphenyl-1-picrylhydrazyl, ferric thiocyanate, thiobarbituric acid, and reducing power assay methods were followed for the antioxidant study. Results: Characterization of the isolated compound confirms it as the flavonoid. Results of the antioxidant study showed that benzene extract has the highest antioxidant activity with a less IC 50 value in comparison to ethyl acetate and ethanol extracts. The isolated compound showed significant antioxidant activity when compared with aspirin. Conclusion: The results of the study suggest that L. crustacea (L) F. Muell is a source of flavonoid which has potent antioxidant activity. Keywords: Lindernia crustacea (L) F. Muell, Flash chromatography, Flavonoid, Antioxidant activity, IC 50 value. INTRODUCTION Oxidation of an oxidizable substrate is significantly inhibited by the antioxidant substances when reacting concentration is less in comparison with that of the substrates [1]. Free radicals are reactive molecules and associated with aging, cancer, strokes, cardiac, DNA destruction, artery obstruction, and central nervous system disorders. There is an increased effort in research on the substances which can prevent the reactive oxygen species and thus can prevent such diseases [2,3]. Many research showed the positive role of flavonoids in the enzymatic action on the brain receptors, and effects on the central nervous system, which included neurodegenerative preventive action associated with Parkinson’s and Alzheimer’s diseases. Free radical scavenging and/or antioxidant activity of flavonoid is already proved by research works. Other pharmacological activities are also possessed by different types of flavonoids [4]. Globally, plants have been used traditionally as medicine to treat diseases, since ancient times [5]. As the natural sources have proved to be a resource of various potent chemical compounds, which are also pharmacologically active, so the global interest has grown to commercialize therapeutic drugs from the natural sources [6]. The potentiality of many such plants remains unexplored and unrevealed. One such plant is Lindernia crustacea (L) F. Muell, which belongs to family Linderniaceae. It is found throughout India in moist places such as river beds, rice fields, and open grassy places [7]. L. crustacea is also a popular and useful ethnomedicinal plant has been traditionally used throughout the world [8]. Previous research work showed the presence of flavonoid in the benzene, ethyl acetate, and ethanol extract of L. crustacea (L) F. Muell with comparatively potent pharmacological activities of benzene extract [9]. There is no research report found on the isolation of flavonoid from L. crustacea and its antioxidant property. Therefore, it was aimed to investigate in vitro antioxidant activity of the extracts and to isolate flavonoid from the potent extract followed by characterization and evaluation of in vitro antioxidant activity of the isolated flavonoid. MATERIALS AND METHODS Materials Analytical grade reagents and solvents used in the study. Silica Gel-G (Merck, India), benzene (Merck, India), ethyl acetate (Merck, India), ethanol (Merck, India), 2, 2′- diphenyl-1-picrylhydrazyl (DPPH, SRL India), thiobarbituric acid (TBA) (Sigma-Aldrich, India), trichloroacetic acid (Merck, India), linoleic acid (Sigma-Aldrich, India), ammonium thiocyanate (SRL India), ascorbic acid (Merck, India), potassium ferricyanide (Merck, India), and ferric chloride (Merck, India) were used during the experimental protocol. Isolation was carried out using flash chromatography (Teledyne ISCO Combi Flash R f 150), and the melting point was determined using DSC (Perkin Elmer, DSC 4000). Instruments used for characterization of the isolated compound are: CHN Analyzer (Perkin Elmer, series II 2400), ultraviolet (UV) spectrophotometer (UV-1800, Shimadzu), infrared spectrophotometer (Alpha-E, Bruker), and 1H NMR and 13C NMR (Bruker Avance II 400 NMR spectrometer) where Tetramethylsilane (TMS) was used as internal reference standard, mass spectrometer (Waters, Q-TOF Micromass, ESI-MS, and mass spectrometer). Preparation of extract and phytochemical analysis The aerial parts of L. crustacea (L) F. Muell were collected from the paddy field of Dharapur, Guwahati, Assam, in the month of April and May and were authenticated by Dr. P.P. Baruah, HOD, Department of Botany, Gauhati University, Guwahati, Assam, as L. crustacea (L) F. Muell with family Linderniaceae and accession number was given for the specimen is 18063. Shade-dried and coarsely powdered aerial parts of L. crustacea were subjected to successive extraction for 72 h by cold maceration in benzene, ethyl acetate, and ethanol. The solvents were filtered and evaporated using rotary evaporator (Buchi, © 2019 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.2019.v12i6.33344 Research Article