Neuroprotective Potential of Polydatin Against Motor Abnormalities and Dopaminergic Neuronal Loss in Rotenone Induced Parkinson Model

Anethole attenuates motor dysfunctions, striatal neuronal activity deficiency and blood brain barrier permeability by decreasing striatal α-synuclein and oxidative stress in rotenone-induced Parkinson's disease of male rats

INTRODUCTION

Anethole is the main compound of the essential oil of anise and several other plants, which has antioxidant, anti-inflammatory, and neuroprotective properties. Oxidative stress is considered as an important factor in the pathogenesis of PD. In the present study, we aimed to investigate the effects of anethole against rotenone-induced PD.

METHODS

Male Wistar rats were randomly divided into six groups. Control group received DMSO + sunflower oil, model group received rotenone (2 mg/kg, s.c, daily for 35 days), positive control group received L-Dopa, and test groups received anethole (62.5, 125, and 250 mg/kg, i.g, daily for 35 days) 1 hour before each rotenone injection. Body weight changes, rotarod test, stride length test, and extracellular single unit recording were performed after treatment. After behavioral test, Brain water content and blood brain barrier (BBB) permeability were evaluated, and the levels of malondialdehyde (MDA), superoxide dismutases (SOD), alpha-synuclein and MAO-B were measured in the striatum.

RESULTS

Chronic administration of rotenone induced body weight loss and caused significant dysfunction in locomotor activity, neuronl firing rate, and BBB. Rotenone also decreased SOD activity, increased MDA level, and elevated the expression of alpha-synuclein and MAO-B in the striatum. However, treatment with anethole attenuated body weight loss, motor function, neuronal activity, and BBB function. Furthermore, Anethole treatment attenuated oxidative stress and decreased the expression of alpha-synuclein and MAO-B compared to the rotenone group.

CONCLUSION

Our results show that through its antioxidant properties, aethole can improve the cellular, molecular and behavioral characteristics of rotenone-induced Parkinson's disease.

Polydatin as a therapeutic alternative for central nervous system disorders: A systematic review of animal studies

Polydatin, or piceid, is a natural stilbene found in grapes, peanuts, and wines. Polydatin presents pharmacological activities, including neuroprotective properties, exerting preventive and/or therapeutic effects in central nervous system (CNS) disorders. In the present study, we summarize and discuss the neuroprotective effects of polydatin in CNS disorders and related pathological conditions in preclinical animal studies. A systematic review was performed by searching online databases, returning a total of 110 records, where 27 articles were selected and discussed here. The included studies showed neuroprotective effects of polydatin in experimental models of neurological disorders, including cerebrovascular disorders, Parkinson's disease, traumatic brain injuries, diabetic neuropathy, glioblastoma, and neurotoxicity induced by chemical agents. Most studies were focused on stroke (22.2%) and conducted in male rodents. The intervention protocol with polydatin was mainly acute (66.7%), with postdamage induction treatment being the most commonly used regimen (55.2%). Overall, polydatin ameliorated behavioral dysfunctions and/or promoted neurological function by virtue of its antioxidant and antiinflammatory properties. In summary, this review offers important scientific evidence for the neuroprotective effects and distinct pharmacological mechanisms of polydatin that not only enhances the present understanding but is also useful for the development of future preclinical and clinical investigations.

The Neuroprotective Role of Polydatin: Neuropharmacological Mechanisms, Molecular Targets, Therapeutic Potentials, and Clinical Perspective

Neurodegenerative diseases (NDDs) are one of the leading causes of death and disability in humans. From a mechanistic perspective, the complexity of pathophysiological mechanisms contributes to NDDs. Therefore, there is an urgency to provide novel multi-target agents towards the simultaneous modulation of dysregulated pathways against NDDs. Besides, their lack of effectiveness and associated side effects have contributed to the lack of conventional therapies as suitable therapeutic agents. Prevailing reports have introduced plant secondary metabolites as promising multi-target agents in combating NDDs. Polydatin is a natural phenolic compound, employing potential mechanisms in fighting NDDs. It is considered an auspicious phytochemical in modulating neuroinflammatory/apoptotic/autophagy/oxidative stress signaling mediators such as nuclear factor-κB (NF-κB), NF-E2–related factor 2 (Nrf2)/antioxidant response elements (ARE), matrix metalloproteinase (MMPs), interleukins (ILs), phosphoinositide 3-kinases (PI3K)/protein kinase B (Akt), and the extracellular regulated kinase (ERK)/mitogen-activated protein kinase (MAPK). Accordingly, polydatin potentially counteracts Alzheimer’s disease, cognition/memory dysfunction, Parkinson’s disease, brain/spinal cord injuries, ischemic stroke, and miscellaneous neuronal dysfunctionalities. The present study provides all of the neuroprotective mechanisms of polydatin in various NDDs. Additionally, the novel delivery systems of polydatin are provided regarding increasing its safety, solubility, bioavailability, and efficacy, as well as developing a long-lasting therapeutic concentration of polydatin in the central nervous system, possessing fewer side effects.

Evaluation of the Neuroprotective Effect of Microglial Depletion by CSF-1R Inhibition in a Parkinson's Animal Model

PURPOSE

Neuroinflammation in Parkinson's disease (PD) is known to play a pivotal role in progression to neuronal degeneration. It has been reported that colony-stimulation factor 1 receptor (CSF-1R) inhibition can effectively deplete microglia. However, its therapeutic efficacy in PD is unclear still now.

PROCEDURES

To elucidate this issue, we examined the contribution of microglial depletion to PD by behavioral testing, positron emission tomography (PET) imaging, and immunoassays in sham, PD, and microglial depletion PD model (PLX3397 was administered to PD groups, with n = 6 in each group).

RESULTS

The microglial depletion in PD model showed improved sensory motor function and depressive-like behavior. NeuroPET revealed that PLX3397 treatment resulted in partial recovery of striatal neuro-inflammatory functions (binding values of [¹⁸F]DPA-174 for PD, 1.47 ± 0.12, p < 0.01 vs. for PLX3397 in PD: 1.33 ± 0.26) and the dopaminergic (binding values of ¹⁸F-FP-CIT for PD, 1.32 ± 0.07 vs. for PLX3397 in PD: 1.54 ± 0.10, p < 0.01) and glutamatergic systems (binding values of [¹⁸F]FPEB for PD: 9.22 ± 0.54 vs. for PLX3397 Tx in PD: 9.83 ± 0.96, p > 0.05). Western blotting for microglia showed similar changes.

CONCLUSION

Microglial depletion has inflammation-related therapeutic effects, which have beneficial effects on motor and nonmotor symptoms of PD.