Neurodegenerative Diseases Retreat in the Face of Therapeutic Advances

Neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis affect millions of people worldwide. Their slow progression and the lack of effective curative treatments make them a major public health challenge. These conditions share common mechanisms, including mitochondrial dysfunction, abnormal protein accumulation, cytoskeletal disruptions, synaptic failures, and chronic inflammation of the nervous system.

In Alzheimer’s disease, the accumulation of beta-amyloid peptides forms plaques that disrupt communication between neurons. These clusters activate the brain’s immune cells, microglia and astroglia, causing persistent inflammation. This reaction worsens synaptic degradation and promotes the formation of tau protein debris, another hallmark of the disease. Together, these processes lead to a progressive loss of memory and cognitive abilities, making daily tasks increasingly difficult.

Parkinson’s disease manifests as tremors, slowed movement, and balance disorders. It is caused by the degeneration of dopamine-producing neurons in a brain region called the substantia nigra. The aggregation of the alpha-synuclein protein forms Lewy bodies, which block dopamine production and disrupt the transmission of nerve signals. Genetic mutations, such as those affecting the PINK1 or Parkin genes, also prevent the elimination of defective mitochondria, thereby worsening oxidative stress and cell death.

Amyotrophic lateral sclerosis attacks motor neurons, causing progressive muscle weakness and paralysis. The accumulation of toxic proteins, such as SOD1 or TDP-43, disrupts mitochondrial function and increases oxidative stress. Additionally, an excess of glutamate, a neurotransmitter, overstimulates NMDA and AMPA receptors, leading to a massive influx of calcium into cells. This mineral imbalance damages mitochondria and accelerates neuronal degeneration.

Current treatments primarily aim to relieve symptoms. For Alzheimer’s, acetylcholinesterase inhibitors, such as galantamine, maintain acetylcholine levels, an essential neurotransmitter for memory. NMDA receptor antagonists, such as memantine, limit excess calcium in neurons, thereby reducing toxicity. In Parkinson’s disease, L-DOPA compensates for the lack of dopamine, while dopaminergic agonists mimic its action. For amyotrophic lateral sclerosis, riluzole reduces excess glutamate, partially protecting neurons.

Innovative approaches are opening new perspectives. Immunotherapy uses antibodies to target clusters of toxic proteins. Antibodies such as lecanemab or aducanumab bind to beta-amyloid plaques, facilitating their elimination by immune cells. For Parkinson’s, antibodies against alpha-synuclein, such as prasinezumab, are being studied to neutralize the aggregates responsible for degeneration.

Gene therapy offers to correct the genetic anomalies at the origin of these diseases. Viral vectors deliver therapeutic genes to the brain to support neuron survival, reduce the accumulation of toxic proteins, or modulate inflammation. For example, genes like NGF or BDNF promote the growth and protection of nerve cells. For amyotrophic lateral sclerosis, gene silencing techniques target mutated SOD1 or C9ORF72 genes, thereby reducing the production of harmful proteins.

Natural compounds also offer promising solutions. Galantamine, extracted from the snowdrop, inhibits acetylcholinesterase and improves Alzheimer’s symptoms. Turmeric and silymarin, thanks to their anti-inflammatory and antioxidant properties, limit protein aggregation and protect neurons. Mucuna pruriens, rich in L-DOPA, alleviates Parkinson’s symptoms while reducing oxidative stress. Niacin, or vitamin B3, stimulates dopamine production and improves motor function in several neurodegenerative diseases.

Nanotechnology is revolutionizing drug delivery. Organic or inorganic nanoparticles cross the blood-brain barrier, a major obstacle for conventional treatments. Exosomes, small vesicles derived from stem cells, modulate inflammation and promote neuronal regeneration. Lipid nanoparticles protect drugs and deliver them directly to affected areas, improving their efficacy. Gold or selenium nanoparticles reduce the accumulation of toxic proteins and oxidative stress in Alzheimer’s and Parkinson’s.

Repurposing existing drugs accelerates the discovery of treatments. Molecules initially developed for other diseases, such as ambroxol for respiratory conditions, show neuroprotective effects against Parkinson’s. This approach reduces costs and development time while providing rapid solutions for patients.

Finally, techniques such as deep brain stimulation help regulate neuronal activity through electrical impulses, improving motor symptoms in Parkinson’s. Advances in artificial intelligence and biomarker discovery are paving the way for earlier diagnoses and personalized treatments tailored to each patient’s specific needs.

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Reference Document

DOI: https://doi.org/10.1186/s13064-026-00279-0

Title: Advances in neurotherapeutics for neurodegeneration

Journal: Discover Neuroscience

Publisher: Springer Science and Business Media LLC

Authors: Daksh Kapur; Deeti Vashisht; Taru Singh