Neurobehavioral Evaluation Of Ethanolic extracts from Newbouldia Laevis leaf in 6-hydroxyldopamine- lesioned rat model of Parkinson’s disease treated with L-DOPA

Abstract

The regeneration of the neuronal system in the injured brain is necessary for the therapeutic treatment of neurodegenerative disorders. In this study we evaluated the effect of the ethanolic extract of Newbouldia laevis on the central nervous system of rats. The extract considerably ameliorated apomorphine-induced rotational behaviour. The lesioned rats displayed contralateral rotation after the administration of apomorphine. Furthermore, pretreatment with different doses of the extract reduced the rotations in a dose-dependant manner. In another experiment, the extract relieved the declined dopamine level in the 6-hydroxydopamine( 6-OHDA) – injured striatum, while the levels of dopamine in rats without 6-OHDA lesions were not altered. Also, animals that received the extract and exposed to chronic stress in levodopa ( L-DOPA) – treated – 6 – OHDA lesioned displayed further decrease in the level of dopamine. The extract was also found to cause considerable reduction of spontaneous motor activity, revealing the neuroprotective and neuro-rescue properties rested in the plant extract. This decrease in activity is closely related to sedation resulting from depression of the central nervous system. Similarly, the loss of tyrosin hydroxylase(TH)-immunopositive neuronal cell induced by the exposure of rats to chronic stress was restored by the administration of the extract 48.4%, 72.6% and 94.6% dose dependently. These findings offered insights into the understanding of the Parkinson,s disease process, its cause or origin. The extract has equally stepped down the prevailing neurodegeneration in Parkinson,s disease.