Biography
Limamanen Phom has completed M.Sc. Zoology from Nagaland University (Central), Nagaland, India. He worked as Research Fellow in the Department of Biotechnology (Government of India) funded research project entitled, Neuroprotective Effects of Natural Products with Antiinflammatory and Antioxidative Properties in Drosophila Model of Parkinson’s Disease and has shown that Curcumin’s neuroprotective efficacy in Drosophila model of Idiopathic Parkinson’s Disease is phase specific which has therapeutic implications for human. Presently, he is pursuing Ph.D under the supervision of Dr. Sarat Chandra Yenisetti.
Abstract
Selective degeneration of dopaminergic neurons in the substantia nigra underlies the basic motor impairments of Parkinson’s disease (PD). Curcumin has been used for centuries in traditional medicines in India. Our aim is to understand the efficacy of genotropic drug curcumin as a neuroprotective agent in PD. Analysis of different developmental stages in model organisms revealed that they are characterized by different patterns of gene expression which is similar to that of developmental stages of human. Genotropic drugs would be effective only during those life cycle stages for which their target molecules are available. Hence there exists a possibility that targets of genotropic compounds such as curcumin may not be present in all life stages. However, no reports are available in PD models illustrating the efficacy of curcumin in later phases of adult life. This is important because this is the period during which late-onset disorders such as idiopathic PD set in. To understand this paradigm, we tested the protective efficacy of curcumin in different growth stages (early, late health stage, and transition phase) in adult Drosophila flies. Results showed that it can rescue the motor defects during early stages of life but is ineffective at later phases. This observation was substantiated with the finding that curcumin treatment could replenish depleted brain dopamine levels in the PD model only during early stages of life cycle, clearly suggesting its limitation as a therapeutic agent in late-onset neurodegenerative disorders such as PD.
Biography
Huamin Xu, Qingdao University, China
Abstract
Rosmarinic acid (RA) is a naturally occurring polyphenolic compound, and is composed of caffeic acid and danshensu. Our previous studies have confirmed RA could protect against 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl pyridine cation (MPP+) induced cell injury. Improving evidence showed iron-induced α-synuclein aggregation played important roles in the etiology of Parkinson's disease (PD). However, whether RA could protect dopaminergic neurons through inhibiting the aggregation of α-synuclein in PD is unclear. And the regulation mechanisms underlying this inhibition were not elucidated. Therefore, the experiment proposed to explore the effects of rosmarinic acid against iron-induced α-synuclein aggregation in dopaminergic cells and elucidate the possible mechanisms in the SK-N-SH cells. Results showed iron could reduce the mitochondrial transmembrane potential (△Ψm) and induce α-synuclein aggregation in the SK-N-SH cells. In accordance with iron responsive element/iron regulatory protein (IRE/IRP) system, iron could increase the mRNA levels of α-synuclein. And results also showed that RA pretreatment could restore the ΔΨm reduction induced by iron and alleviate iron induced α-synuclein aggregation. Further results showed RA pretreatment could inhibit iron induced α-synuclein aggregation by up-regulating hemeoxygenase-1 (HO-1). In addition, RA pretreatment could decrease the mRNA levels of α-synuclein via decreasing the protein levels of IRP1. These results provide new findings and new strategies for the prevention and treatment of PD.