Parkinson’s disease (PD) is a common progressive neurodegenerative disease in middle aged and elderly people. The prevalence of PD in people aged more than 65 is 1.7%, posing a serious threat to the health of middle-aged and elderly people. Till now, no effective treatment is available that would slow down or halt PD progression.
It is characterized by static tremors, myotonia, bradykinesia, abnormal posture, and gait. The core pathological mechanism of PD is that degeneration or necrosis of dopaminergic neurons in the mesencephalic substantia nigra leads to a considerable reduction of the striatum dopamine content. Presently, the primary treatment of PD is dopamine substitution therapy; however, after its long-term use, its efficacy is reduced and adverse reactions are increased.
Acupuncture is most commonly used as a complementary therapy for PD. It can improve PD symptoms, reduce adverse drug reactions, prevent the progression of disease, and improve the quality of patients’ life.
Study on the mechanism of acupuncture therapy for PD
Regulating dopaminergic neuron secretion in substantia nigra:
Studies have found that acupuncture can improve the ethology and pathology of mice with PD. Its mechanism of action may be realizing the above process by increasing TH expression in the substantia nigra and reducing the loss of dopaminergic neurons in mice.
Improvement of oxidative stress:
Glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) are essential enzymes that catalyze the decomposition of hydrogen peroxide in the body. It has been discovered that the function of the antioxidant system in PD model rats was decreased, whereas SOD, GSH-Px activity, and GSH content decreased. Electroacupuncture can improve the antioxidant capacity of PD model rats and reduce the damage of oxygen-free radicals on brain tissue.
Inhibition of inflammatory response:
During the PD pathological process, neuronal degeneration and necrosis and inflammatory response are related to microglial activation, the pathological characteristics of which are abnormal aggregation and phosphorylation of α-synuclein in the specific regions of the central nervous system. electroacupuncture can regulate the MAPK/JNK signaling pathway in PD model rats, decrease the expression of p-c-Jun in the substantia nigra, and reduce the expression of inflammatory factors TNF-α, IFN-γ, and IL-1β.
Acupuncture (Yang Mausoleum, dance tremor control area) in the rat 6-OHDA model of PD could increased the levels of CD3, CD4, and CD8 in the blood of rats and decreased the concentration of tumor necrosis factor (TNF)-α.
Excitatory amino acids, including glutamic acid (Glu) and aspartic acid, can cause toxic effects on neurons when they are released excessively or the inactivation mechanism is damaged. the electroacupuncture can increase the expression and activity of glutamate transporter in the brain and reduce the cytotoxicity caused by extracellular Glu.
Regulating Abnormal Calcium Homeostasis
Abnormal calcium homeostasis is one of the important factors in the apoptosis of dopaminergic neurons in the substantia nigra of patients with PD. Under normal conditions, intracellular calcium homeostasis is regulated by membrane calcium pump and intracellular calcium pool. If the cells are damaged, the permeability of cell membrane increases and a large number of extracellular calcium ions flow into the cell. Because of the damage in sarcoplasmic reticulum caused by free radical and membrane phospholipid decomposition, calcium pump inhibition leads to a decrease in calcium intake of sarcoplasmic reticulum and an increase in calcium concentration in the cytoplasm, endangering mitochondrial function and cytoskeletal structure and eventually causing irreversible cell death. Different scalp acupuncture treatment in the rat 6-OHDA model of PD, could improve the activity of Ca2+-ATPase in the substantia nigra of PD rats and intracellular calcium homeostasis. Simultaneously, it could also improve Na+-K+-ATP enzyme, Ca2+-Mg2+-ATP enzyme, and total antioxidant capacity, thereby improving brain energy metabolism, reducing brain injury by free radicals, and alleviating the apoptosis of nerve cells
Regulating mitochondrial dysfunction:
During the onset of PD, the decrease of mitochondrial complex activity in brain tissue will reduce the synthesis of ATP, thereby leading to the inability of membrane potentials to maintain balance, which in turn will cause electrons to leak from the respiratory chain, increase the production of reactive oxygen species, and cause the degeneration of dopaminergic neurons. Acupuncture at Baihui (DU 20) and Dazhui (DU 14) acupoints can reduce mitochondrial structural damage, and increase the activity of mitochondrial complex II.
Main Influence of Acupuncture on Parkinson’s Disease
Improvement of Life Quality of PD Patients
Although the drugs can improve the motor function of patients with PD, they often produce a series of side reactions, resulting in a large number of complications, affecting the patient’s mental status and daily life. The efficacy of acupuncture on patients of PD with depression was assessed by using the Hamilton Depression Rating Scale (HAMD) score and UPDRS before and after treatment. The results showed that the scores of HAMD and UPDRS III decreased after acupuncturing Fengfu and Taichong points on the 14th day after treatment. The effective rate was 80.9% in the treatment group and 28.6% in the control group (P < 0.05), suggesting that acupuncture at Fengfuxue and Taichong had a significant effect on PD depression
Relief of Movement Dysfunction
Recent report used the “skull base seven points” acupuncture method to evaluate the efficacy of Parkinson’s disease. It is believed that the “Skull Base Seven Points” acupuncture method can improve PD patients’ clinical symptoms and its clinical effect is better than that of conventional western medicine. It can improve the limb flexibility of patients with PD, and improve the patient’s stiffness, flexion posture and facial appearance.
Effect of Acupuncture on Electroencephalogram in PD Patients
The frequency of brain electrical activity can reflect the functional status of a certain area of the brain and is an important parameter in brain development and aging. Reduced metabolism of brain cells, slower nerve fiber conduction velocity, and degeneration of neurons may increase the power of the θ and δ bands and reduce the power of α and β bands. Studies showed that the power of brain electrical activity in PD patients had increased in the θ and δ bands and decreased in the α and β bands, and this change degree of brain power spectrum was positively correlated with the condition of PD. Quantitative EEG analyses were performed in 45 patients with PD before and after acupuncture treatment. They found that the relative power values of α and β waves were significantly increased after 30 days’ acupuncture, and the relative power values at θ and δ bands were significantly decreased, which showed that acupuncture improved the brain function of patients with PD. The objective evidence for the efficacy of acupuncture on PD was also supported by the observation.