Abstract
PURPOSE: This review aims to elucidate the molecular mechanisms underlying the neuroprotective effects of acupuncture in preclinical models of Parkinson's disease (PD). FINDING: In PD animal models, acupuncture inhibits oxidative stress by upregulating nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) while reducing malondialdehyde (MDA) and lipid peroxidation. It regulates autophagy either independently of mammalian target of rapamycin (mTOR) or via mTOR activation, promoting alpha-synuclein (α-synuclein) clearance. Acupuncture also suppresses apoptosis (modulating Bcl-2-associated X protein (Bax)/B-cell lymphoma 2 (Bcl-2)) and pyroptosis (inhibiting NLR family pyrin domain containing 3 (NLRP3) inflammasome and gasdermin D (GSDMD)). It enhances neurogenesis through brain-derived neurotrophic factor (BDNF)/extracellular signal-regulated kinase (ERK)/cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) and glial cell line-derived neurotrophic factor (GDNF) signaling, promoting neural stem cell proliferation and differentiation. Furthermore, acupuncture reduces neuroinflammation by decreasing microglial activation, cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β). It also modulates gut microbiota composition (e.g., increasing butyrate-producing bacteria like Butyricimonas and reducing pro-inflammatory Erysipelotrichaceae and Bacteroides) and influences lipid metabolism, thereby mitigating dopaminergic neuron loss and motor deficits. CONCLUSION: Preclinical evidence demonstrates that acupuncture exerts multi-target neuroprotective effects against PD through pathways involving oxidative stress, autophagy, apoptosis/pyroptosis, neurogenesis, neuroinflammation, and gut microbiota-lipid metabolism crosstalk. However, limitations include a focus on preventive rather than reversal effects, lack of long-term efficacy data, and heterogeneity in acupoint selection. Further mechanistic and standardization studies are warranted.