Phytomedicine Plus (Aug 2022)
Treatment with bark extracts of Voacanga africana attenuates motor coordination deficit, depressive-like behavior and microglial reaction, in a mouse model of early Parkinson's disease
Abstract
Background: Voacanga africana (VOC) has been widely used for many years in the African traditional medicine system for the treatment of a wide range of diseases, including mental disorders but VOC has never been tested in vivo in the context of neurodegenerative diseases for its potential symptomatic and/or disease-modifying action. Purpose: We aim to evaluate the behavioral, neuroprotective and anti-inflammatory effects of VOC bark extracts in a mouse model of Parkinson's disease (PD) mimicking the early stages of the disease characterized by non-motor deficits and mild motor symptoms. Methods: Bilateral injections of 6-hydroxydopamine (6-OHDA) were performed in the striatum of mice and VOC was injected intraperitoneally every day for 20 days in a group of 6-OHDA-injected mice. Rotarod, forced swim test and open field test were used to examine behavioral deficits. Dopaminergic neurodegeneration and microglial activation were assessed using quantitative immunohistochemistry. Results: VOC treatment reversed the lesion-induced decrease in fall latency in the rotarod test and the increase in immobility time measured in the forced swim test, suggesting improved motor coordination and reduced depressive-like behavior. In the open field test, the distance travelled, which assesses gross locomotor activity, and the time spent in the center, which is considered as an index of anxiety, were not significantly modified in 6-OHDA lesioned mice either treated or not with VOC. VOC treatment in 6-OHDA-lesioned mice mitigated the increase of IBA1 immunoreactivity but had no effect on the lesion-induced loss of TH-positive fibers in the striatum and neurons in the substantia nigra, suggesting a modest anti-inflammatory effect that did not translate into efficient neuroprotection. Conclusion: These experiments, which evaluate for the first time the effect of VOC bark extracts in a model of early PD, show that VOC treatment improves depressive-like and motor behaviors without inducing a generalized hyperactivity and attenuates neuroinflammation, suggesting its possible use in prodromal PD.
