ABSTRACT
Spinocerebellar ataxia type 3 (SCA3) is an autosomal dominant neurodegenerative disorder that gives rise to motor incoordination and progressive functional disabilities. Although pharmacological interventions have revealed promising prospects in the management of SCA3, adverse effects may become unbearable. The use of herbal remedies in traditional Chinese medicine (TCM) may serve as potential alternative medicines to delay the progression of the disease. This systematic review is intended to identify, appraise, and summarize the findings of studies pertaining to the therapeutic roles of herbal remedies in TCM targeting oxidative stress in the management of SCA3. A literature search for relevant articles published from 1 January 2013 to 30 June 2023 in three databases, namely PubMed, Web of Science, and Scopus, was carried out according to the procedures of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A total of ten preclinical studies met the inclusion criteria of the systematic review. We recognized the therapeutic potential of Brassica napus, Codonopsis pilosula, Curcuma sp., Gardenia jasminoides, Gastrodia elata, Ginkgo biloba, Glycyrrhiza inflata, Hericium erinaceus, Hyptis sp., Paeonia lactiflora, Panax ginseng, Poria cocos, Pueraria lobata, Rehmannia glutinosa, and Scrophularia ningpoensis. We identified the types of preclinical models expressing polyglutamine (polyQ) expanded mutant protein (mATXN3), inducers of oxidative stress that mimic the SCA3 pathogenesis, and effective doses of the herbal remedies. The modes of action contributing to the attenuation of oxidative stress are activation of antioxidant pathways, ubiquitin-proteasome system and autophagy, regulation of apoptosis, proinflammatory signaling pathway and chaperones, regulation of mitochondrial function and biogenesis, and restoration of neurotransmission and synaptic plasticity. In conclusion, herbal remedies in TCM may possibly delay the progression of SCA3, therefore providing justification for clinical trials.
ABSTRACT
Adenosine is a nucleoside that is widely distributed in the central nervous system and acts as a central excitatory and inhibitory neurotransmitter in the brain. The protective role of adenosine in different pathological conditions and neurodegenerative diseases is mainly mediated by adenosine receptors. However, its potential role in mitigating the deleterious effects of oxidative stress in Friedreich's ataxia (FRDA) remains poorly understood. We aimed to investigate the protective effects of adenosine against mitochondrial dysfunction and impaired mitochondrial biogenesis in L-buthionine sulfoximine (BSO)-induced oxidative stress in dermal fibroblasts derived from an FRDA patient. The FRDA fibroblasts were pre-treated with adenosine for 2 h, followed by 12.50 mM BSO to induce oxidative stress. Cells in medium without any treatments or pre-treated with 5 µM idebenone served as the negative and positive controls, respectively. Cell viability, mitochondrial membrane potential (MMP), aconitase activity, adenosine triphosphate (ATP) level, mitochondrial biogenesis, and associated gene expressions were assessed. We observed disruption of mitochondrial function and biogenesis and alteration in gene expression patterns in BSO-treated FRDA fibroblasts. Pre-treatment with adenosine ranging from 0-600 µM restored MMP, promoted ATP production and mitochondrial biogenesis, and modulated the expression of key metabolic genes, namely nuclear respiratory factor 1 (NRF1), transcription factor A, mitochondrial (TFAM), and NFE2-like bZIP transcription factor 2 (NFE2L2). Our study demonstrated that adenosine targeted mitochondrial defects in FRDA, contributing to improved mitochondrial function and biogenesis, leading to cellular iron homeostasis. Therefore, we suggest a possible therapeutic role for adenosine in FRDA.
