Neuroprotective effects of Korean medicinal plants in animal model of Parkinson's disease

Parkinson's disease is a neurodegenerative disorder characterized by progressive loss of dopaminergic neurons in the substantia nigra pars compacta and is the most prevalent movement disorder.¹ Inflammation-mediated cell death is thought to contribute to dopaminergic cell death.^2,3 In this study, extract of some Korean medicinal and edible plants such as Daphne genkwa Siebold. & Zucc. [Thymelaeaceae] were found to attenuate motor dysfunction in 6-OHDA-induced Parkinson's disease rat model and exhibited a protective effect against 6-OHDA-induced dopaminergic neuronal cell death. Two active compounds, genkwanine N (1) and yuanhuacin (2) were isolated through bioactivity-guided fractionation from the extract and their chemical structures were identified by NMR and MS analyses. The compounds reduced the expression of proinflammatory genes including interleukin-1β (IL-1β) and interleukin-6 (IL-6) in microglia and prevented 6-OHDA-induced neuronal cell death. Importantly, in the 6-OHDA rat model of Parkinson's disease, oral administration of yuanhuacin (0.5 mg/kg/day) for 2 weeks significantly improved behavioral deficits and reduced tyrosine hydroxylase (TH)-positive dopaminergic neuron death induced by 6-OHDA injection. Additionally, microglia activation in dorsal striatum was inhibited, suggesting anti-parkinson effects of the compounds are related to their anti-inflammatory activity. These results suggest that the extract and the compounds could be promising candidates for the treatment of Parkinson's disease.

Acknowledgements: This work was supported by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries (IPET) through Agri-Bio industry Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA) (114145 – 3).

Keywords: Neuroprotective, Parkinson's disease, inflammation, dopaminergic neurons, 6-OHDA rat model.

References:

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