MYRICETIN ISOLATED FROM TURBINARIA ORNATA AMELIORATES ROTENONE INDUCED PARKINSONISM IN DROSOPHILA MELANOGASTER Original Article VIJAYRAJA DHANRAJ 1 , TAMILARASAN MANIVASAGAM 2 , JEYAPRAKASH KARUPPAIAH 3 1 Research and Development Centre, Bharathiar University, Coimbatore 641046, Tamilnadu, India, 2 Department of Biochemistry and Biotechnology, Annamalai University, Chidambaram 608002, Tamil Nadu, India, 3 PG and Research Department of Biochemistry, Rajah Serfoji Government College, Thanjavur 613005, India jeypee5@gmail.com Email: Received: 13 May 2017 Revised and Accepted: 21 Sep 2017 ABSTRACT Objective: Parkinson’s disease (PD) is a neurodegenerative disorder which affects the elderly population. Free radicals overproduction, oxidative stress, apoptosis, inflammation and abnormalities in mitochondria are critical mediators of the neuronal degeneration. In the present study neuroprotective activity of myricetin, a flavonoid isolated from brown seaweed Turbinaria ornata have been investigated in rotenone induced experimental PD models of Drosophila melanogaster. Methods: Male fruit flies (Drosophila melanogaster) were fed with an effective dose of 0.1% myricetin three hours before to the treatment with 500 µM of Rotenone (LD 50) for seven days and on 8 th Results: Myricetin maintains the positive behavioral patterns against motor impairments due to the rotenone toxicity, it creates a balance in oxidant and antioxidant status, reduces the oxidative stress and inhibits apoptosis to retard neurodegeneration and maintains the dopamine level with a significant (p<0.05) difference compared to the rotenone treated group. day through behavioral analysis the neuroprotective effect of myricetin was investigated for motor coordination in fruit flies. Lipid peroxidation was analyzed by estimating the levels of TBARS. Oxidative stress was determined by estimating the activities of enzymatic antioxidants superoxide dismutase, catalase, and glutathione peroxidase along with the level of reduced glutathione. Dopamine level was estimated in HPLC column detected at 280 nm with UV detectors and degree of apoptosis was studied apoptotic marker Bcl-2, Bax, caspases-3 and 9, cytochrome c and β-actin expressions in the whole body homogenate of fruit flies of experimental groups homogenized in 500μL of 0.1 M phosphate buffers (ice cold, pH, 7.4) containing 1 mmol EDTA. Conclusion: The flavonoid myricetin by reducing the oxidative stress, maintaining the enzymatic antioxidants status and by inhibiting apoptosis prevents the degeneration of dopaminergic neurons. The dopaminergic neurons prevention reduces the depletion of dopamine and thereby promotes the muscular coordination and psychological well being of fruit flies of experimental group. Further in depth molecular level studies are in need to explore the preventive mechanisms of myricetin in Parkinson’s disease. Keywords: Parkinson’s disease, Myricetin, Rotenone, Climbing assay, Apoptosis © 2017 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/ijpps.2017v9i11.19931 INTRODUCTION Parkinson’s disease (PD) is the common neurodegenerative movement disorder next to Alzheimer’s disease, with multiple factors of etiology which leads to the death of dopaminergic neurons in the aged population of 60 y. The degeneration of dopaminergic neurons of substantia nigra pars compacta (SNpc) is the pathology of the disease which reduces the level of the neurotransmitter called dopamine (DA), which is involved in the locomotory event of the body. Dopamine depletion causes a negative impact on the motor circuit regulation of basal ganglia. This leads to motor impairment such as bradykinesia, muscular rigidity, tremor, and postural instability [1]. Free radical overproduction, oxidative stress, apoptosis, inflammation and abnormalities in mitochondria are critical mediators of the neuronal degeneration in PD [2]. Since the brain is sensitive to oxidative damage because of its peroxidizable fatty acid composition, consumes excess oxygen and not well enriched in antioxidant defenses. In addition, reactive oxygen species (ROS) produced enormously due to endogenous and exogenous stimuli leads to induction of signal transduction that cause mitochondrial dysfunction and cell death [3]. An important hallmark of PD is Lewy’s body inclusions, which are formed in dopaminergic cell aggregation area like substantia nigra (SN), dorsal nucleus of the vagus nerve and leads to the degeneration of DA neurons. Decrease in dopamine level forms the imbalance between dopaminergic and acetylcholine system which develops a series of PD symptoms [4, 5]. Targeting phytochemicals and bioactive compounds from nature are significant in treating neurodegenerative diseases. Seaweeds are rich in bioactive compounds like sulfated polysaccharides, phlorotannins, flavonoids and diterpenes are having a prominent role in therapeutics research [6]. Turbinaria ornata, spiny leaf seaweed has been studied for its antioxidant, antiulcer, and wound healing, anti-inflammatory activity and hepatoprotective activities; in our previous studies, also we have elucidated the in vitro antioxidant activity it [7], free radical scavenging, antihemolysis and anti- inflammatory activity of Turbinaria ornata methanolic extract [8]. In the present study neuroprotective activity of myricetin, a flavonoid isolated from Turbinaria ornata has been investigated in experimental PD models of Drosophila melanogaster. MATERIALS AND METHODS Chemicals and reagents Myricetin (Isolated from Turbinaria ornata), rotenone, thio- barbituric acid (TBA), reduced glutathione and 3, 5-dithio-bis- nitrobenzoic acid (DTNB), xanthine, xanthine oxidase, bovine serum albumin (BSA), primary and secondary antibodies were purchased from Sigma chemical Company, Bangalore, India. All other reagents were of analytical grade and were procured locally. Collection of samples The marine brown alga Turbinaria ornata was collected by hand picking from intertidal waters of the Mandapam coast (Longitude 78 ° 8’E, Latitude 90 ° 17’ N) in the Gulf of Mannar during the early hours in the month of May. The algal material was identified and authenticated in BSI Coimbatore, Tamilnadu (BSI/SRC/5/23/ 2015/Tech./1304). A voucher specimen was maintained in our International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 9, Issue 11, 2017