Neuroprotective role of traditional Chinese plant extracts on Parkinson's disease; a comprehensive preclinical review

Abstract

Introduction

Parkinson's disease (PD) is a complex neurodegenerative disorder primarily characterized by gradual loss of dopaminergic neurons in the substantia nigra of the midbrain. Despite extensive research, a definitive cure that alters the progression of PD remains elusive. Herbal remedies, particularly those employed in Traditional Chinese Medicine (TCM), have been used for centuries in Asia to manage neurological conditions. Recently, there has been a renewed interest in these treatments, motivated by their potential to inform the development of pharmaceuticals that not only address PD symptoms but also modify the underlying disease mechanisms. Highlighting the urgency of this research, the increasing global prevalence of PD, expected to affect approximately 12 million individuals by 2040, underscores the urgent need for novel therapeutic strategies. Additionally, the limitations of current treatments, which often have come with significant side effects, create a compelling case for exploring the neuroprotective properties of TCM.

Methods

This review outlines the pathogenic mechanisms underlying PD including protein aggregation, mitochondrial dysfunction, ion imbalance, neuroinflammation, and oxidative stress. An extensive literature search was conducted using the PubMed and Web of Science, focusing on studies that examined Chinese herbal remedies and their key bioactive compounds in the context of PD. Articles were selected based on relevance, research rigor, and the availability of data from both in vitro and in vivo PD models. Keywords used, included “Parkinson's disease,” “Traditional Chinese Medicine,” “bioactive compounds,” “oxidative stress,” and “neuroinflammation.”

Results

This review identified several TCM herbal preparations and their primary bioactive components that have shown promising effects in PD models. These compounds, including Ginsenosides, Epigallocatechin gallate, Curcumin, Sesamin, Eleutheroside B, Saponin, Theacrine, Ginkgetin, and Gypenosides, were analyzed for their mechanisms of action. The neuroprotective effects of these compounds are linked to the pathways associated with oxidative stress, inflammation, and cellular protection. Extraction methods, primarily ethanol- or water-based methods, play a significant role in isolating these active ingredients.

Discussion

The findings indicate that TCM herbs and their bioactive constituents may offer valuable insights for developing PD-modifying therapies. The studied compounds demonstrated effects on essential signaling pathways related to oxidative and inflammatory stress in neurons. Understanding these mechanisms may guide the development of novel therapeutics aimed at slowing or altering PD progression. This review highlights the potential of integrating traditional herbal knowledge with modern scientific research to meet the unmet needs of patients with PD.