Effect of sulfated polysaccharides from cuttle bone of sepia Pharanois on Rotenone induced Parkinsons disease in Zebra fish

Abstract

newline Parkinson s disease (PD) is the second most common age related neurodegenerative disease that represents a growing socioeconomic burden on the societies. Complete cure for PD has not yet been worked out, since current pharmacological and surgical therapies are limited in inhibiting the progression of PD. Therefore there is current interest in the development newer drug for PD. The present study was aimed to isolate, structurally characterize the low molecular weight sulfated chitosan (LMWSC) from the cuttlebone of Sepia pharaonis and evaluate its potential using Zebrafish model for PD. Elemental analysis of LMWSC established the presence of C, H, N and the occurrence of sulfation of LMWSC was confirmed by characteristic peaks in FT-IR and FT-Raman spectra. The molecular structure and sulfation sites of LMWSC were confirmed using 1D, 2D NMR - 1H, 13C, 2D - COSY and HSQC spectroscopy. The thermal property of LMWSC was studied by thermogravimetric analysis and the fragment obtained after irradiation was water soluble sulfated chitosan with a molecular weight of 460 Da, determined by MALDI TOF/MS.The present study also evaluated in vitro neuroprotective effects of LMWSC against rotenone-induced toxicity in human dopaminergic cells, SH-SY5Y. Cells exposed to rotenone for 24 h- suffered cellular injury and apoptotic cell death. Results suggest pretreatment of cells with LMWSC provided significant protection to SH-SY5Y cells and it could be due to the antioxidant, mitochondrial protection, and anti-apoptotic properties of LMWSC. The toxicity and teratogenic activity of the LMWSC were studied in zebrafish model and the embryo toxicity showed dose-dependent behaviour. At concentrations 50 µM, LMWSC induced malformations like embryo deformity, spine bend and curved tail. The study primarily first challenged zebrafish larvae with rotenone immersion and found a significant reduction in zebrafish locomotor activity, touch response and edge preference. Pretreatment with 20 µM of LMWSC reversed the locomotor disruptions. This study, also investigated the treatment of newline4 weeks of rotenone to adult zebrafish showed this variety of motor PD-like symptoms. Compared with control group, rotenone-treated group showed low swimming speed, indicating a deficit in motor function. In the light-dark box test, rotenone-treated group exhibited longer latencies to enter the dark compartment and longer time in the light compartment which may be reflecting the anxiety and depression-like behaviour. These behavioral symptoms were associated with decreased levels of dopamine in the brains of rotenone-treated fish. Treatment with LMWSC 20 mg/L attenuated the rotenone induced symptoms in Zebrafish. The above results strongly suggested that the LMWSC from S. pharaonis holds immense potentials as a viable drug for neurological diseases. newline