Zingiber officinale Roscoe extract improves nigrostriatal dopaminergic activity in rotenone-induced Parkinsonian mice: Implication of COX-2/TNF-α/IL-6 and antioxidant enzyme crosstalk in the immunoinflammatory responses

Abstract

Parkinson's disease (PD) is a chronic neurodegenerative disease that occurs progressively with time. Current PD treatments are symptomatic with moderate effects on striatal dopamine release. Previously, the ethnomedicinal benefits of Zingiber officinale Roscoe have been demonstrated to possess a broad range of pharmacological benefits, but no single data on its effect against nigrostriatal degeneration in PD model has been reported. Proactive neuroprotective and pharmacotherapeutic approaches with asymptomatic effects are needed to prevent the progression of Parkinson's disease (PD) and maintain the appropriate population of dopaminergic neurons. Current treatments are symptomatic and can only elevate the striatal dopamine levels. Hence, the objective of the study is to elucidate the neuroprotective and neurorestorative properties of Zingiber officinale methanol extract (MEZO) on nigrostriatal degeneration implicated by immunoinflammatory responses in rotenone-challenged PD mice model. Male Swiss mice were injected with rotenone (2.5 mg/kg) intraperitoneally to induce PD symptoms 30 minutes prior to MEZO (50 and 100 mg/kg) and LD-CD (10 mg/kg) oral treatment for 28 days. Motor/neuromuscular behavior, dopamine, acetylcholinesterase (AChE), tyrosine hydroxylase (TH), α-synuclein (α-syn), cyclooxygenase-2 (COX-2), oxidative stress markers, inflammatory cytokines, and histopathology were evaluated. Our data showed that MEZO treatment attenuated sensorimotor and neuromuscular incompetence by up-regulating the expression of TH protein and dopamine release and maintaining AChE enzyme in the symptomatic mice. We observed that MEZO treatment prevented the formation of Lewis bodies (LBs) by inhibiting the aggregation of nigrostriatal α-Syn proteins, decreasing the release of pro-oxidant and pro-inflammatory mediators and cyclooxygenase-2 (COX-2) protein expression, increasing glutathione enzymes, and moderately abated the loss dopaminergic neurons in a dose-dependent effect in the symptomatic mice. These findings demonstrated that MEZO exhibited the potential neuroprotective and neurorestorative effect in the treatment and management of PD.