MYRICETIN ISOLATED FROM TURBINARIA ORNATA AMELIORATES ROTENONE INDUCED PARKINSONISM IN DROSOPHILA MELANOGASTER

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 8th 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.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.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.