Efficacy of Traditional Herbal Medicine Treatment Based on Pattern Identification for Idiopathic Parkinson’s Disease: A Protocol for Systematic Review and Meta-Analysis

The Potentiality of Natural Products and Herbal Medicine as Novel Medications for Parkinson's Disease: A Promising Therapeutic Approach

As the global population ages, the prevalence of Parkinson's disease (PD) is steadily on the rise. PD demonstrates chronic and progressive characteristics, and many cases can transition into dementia. This increases societal and economic burdens, emphasizing the need to find effective treatments. Among the widely recognized causes of PD is the abnormal accumulation of proteins, and autophagy dysfunction accelerates this accumulation. The resultant Lewy bodies are also commonly found in Alzheimer's disease patients, suggesting an increased potential for the onset of dementia. Additionally, the production of free radicals due to mitochondrial dysfunction contributes to neuronal damage and degeneration. The activation of astrocytes and the M1 phenotype of microglia promote damage to dopamine neurons. The drugs currently used for PD only delay the clinical progression and exacerbation of the disease without targeting its root cause, and come with various side effects. Thus, there is a demand for treatments with fewer side effects, with much potential offered by natural products. In this study, we reviewed a total of 14 articles related to herbal medicines and natural products and investigated their relevance to possible PD treatment. The results showed that the reviewed herbal medicines and natural products are effective against lysosomal disorder, mitochondrial dysfunction, and inflammation, key mechanisms underlying PD. Therefore, natural products and herbal medicines can reduce neurotoxicity and might improve both motor and non-motor symptoms associated with PD. Furthermore, these products, with their multi-target effects, enhance bioavailability, inhibit antibiotic resistance, and might additionally eliminate side effects, making them good alternative therapies for PD treatment.

Efficacy of herbal medicine treatment based on syndrome differentiation for Parkinson's disease: A systematic review and meta-analysis of randomized placebo-controlled clinical trials

Background: Parkinson's disease (PD), the second most common progressive neurodegenerative disease, causes heterogeneous clinical symptoms. Patients experience a range of motor and non-motor symptoms, and personalized diagnosis and treatment are needed. In traditional East Asian medicine, syndrome differentiation (SD) is a diagnostic approach for customized therapy that uses a comprehensive analysis and varies for the same disease. We aimed to evaluate the efficacy of herbal medicine (HM) prescribed according to the SD of PD. Methods: Ten electronic databases were searched from inception to August 2021 without language limitations. All randomized controlled trials (RCTs) involving HM for SD of PD were included. Assessment of Cochrane's risk of bias and meta-analysis and Grading of Recommendations Assessment, Development, and Evaluation was also performed. Effect measurement was summarized using the mean difference (MD) with 95% confidence interval, through a meta-analysis. Results: Thirteen RCTs involving 843 participants were included. The overall risk of bias was either low or unclear. Compared with the placebo, a combined therapy of HM and Western medicine (WM) significantly improved the total Unified Parkinson's Disease Rating Scale (UPDRS) (MD = -8.03, [-10.27, -5.79], p < 0.00001; I² = 0%) and was more beneficial, as assessed using the UPDRS (I-III), the Parkinson's Disease Questionnaire-39, and the Non-Motor Symptoms Scale. Adverse events did not differ between the groups. Conclusion: The findings suggest that the combined treatment of WM and HM based on SD diagnosis has additional benefits in PD treatment. However, the methodological quality of the included RCTs was suboptimal. Nevertheless, this systematic review is the first to investigate the efficacy of HM treatment according to the SD diagnosis in PD. The clinically meaningful improvement in HM according to SD in PD needs to be tested in further studies with rigorous designs and longer follow-up periods. Systematic Review Registration: [https://inplasy.com/inplasy-2021-10-0020/], identifier [INPLASY2021100020].