Brain Plasticity
Brain plasticity refers to the brain's ability to change its structure and function in response to experiences, learning, and environmental stimuli [
21]. It is a fundamental process that allows the brain to adapt, learn, and recover from injuries or diseases [
22]. Plasticity can occur at the cellular and molecular levels, leading to changes in neuronal properties, synaptic connections, and neural networks [
23].
Research has shown that brain plasticity is present throughout the lifespan, although the efficiency of plasticity may decline with age [
24]. Genetic factors also play a role in brain plasticity, with heritability estimates suggesting that genetic variations contribute to interindividual variability in plasticity [
25].
The mechanisms of brain plasticity refer to the processes by which the brain can reorganize and modify its neural connections in response to numerous factors such as experience, learning, injury, and disease. These mechanisms include:
Brain plasticity involves modifications in the strength and number of connections between neurons, known as synapses. This can occur through processes such as long-term potentiation (LTP) and long-term depression (LTD), which are activity-dependent changes in synaptic transmission.
Plasticity can also involve the creation of new synapses between neurons. This process, known as synaptogenesis, allows for the establishment of new connections and the rewiring of neural circuits.
Plasticity can lead to alterations in the structure and function of individual neurons. This can include changes in dendritic branching, axonal sprouting, and the generation of new neurons through neurogenesis.
Plasticity can be influenced by changes in the levels and activity of various neurotransmitters and neuromodulators. These substances can affect synaptic transmission and neuronal excitability, thereby influencing the plasticity of neural circuits.
Plasticity mechanisms rely on
complex signalling cascades within neurons. These pathways involve the activation of specific genes and the production of proteins that regulate synaptic plasticity and neuronal connectivity [
26,
27,
28].
Brain plasticity has important implications in various contexts, including neurodevelopmental disorders, addiction, stroke recovery, and neurodegenerative diseases [
22,
29,
30].
Physical activity has a significant impact on brain plasticity, which refers to the brain's ability to reorganize and modify its neural connections. Several studies have shown that physical activity can enhance brain plasticity and promote various neuroadaptive processes.
One study found that voluntary exercise in rats increased both precursor and mature forms of brain-derived neurotrophic factor (BDNF) in the hippocampus, a region important for learning and memory [
31]. BDNF is a neurotrophic factor that plays a crucial role in synaptic plasticity and neuronal survival. Exercise also increased the activity of tissue-type plasminogen activator (tPA), an enzyme involved in the cleavage of proBDNF into mature BDNF. Blocking tPA activity reduced the exercise-induced effects on BDNF and its downstream signalling pathways [
31].
Regular physical activity has also been shown to enhance brain plasticity in humans. Studies have demonstrated that aerobic exercise, anaerobic exercise, and resistance exercise can positively influence brain plasticity and cognitive function [
32]. These exercise modalities can lead to changes in the expression of neurotrophic factors, such as BDNF, lactate, and vascular endothelial growth factor (VEGF), which promote neurogenesis and synaptic plasticity [
32].
Furthermore, physical activity can reduce short interval intracortical inhibition (SICI), a measure of cortical inhibition, and create a more optimal environment for plasticity [
33]. Exercise-induced reductions in SICI may contribute to enhanced neuroplasticity and improved motor learning [
33].
Overall, physical activity has been shown to promote brain plasticity through various mechanisms, including the upregulation of neurotrophic factors, modulation of synaptic activity, and reduction of cortical inhibition. These findings highlight the importance of regular physical activity for maintaining and enhancing brain health and function [
31,
32,
33,
34,
35,
36].
There is limited information available specifically addressing the adverse effects of MS medications on brain plasticity. However, some studies suggest that certain medications used to treat MS may have a positive impact on brain plasticity by reducing inflammation and promoting recovery. One study found that treatment with interferon beta-1a, a commonly used MS medication, improved cortical function and cognitive deficits in newly diagnosed MS patients with gadolinium-enhancing lesions [
37]. Another study showed that reduction of inflammation with interferon beta was associated with the restoration of brain plasticity in MS patients, as evidenced by improvements in task performance and synaptic plasticity [
38].
It is important to note that the studies mentioned above focused on the positive effects of MS medications on brain plasticity, rather than adverse effects. Adverse effects of MS medications can vary depending on the specific medication and individual patient factors. It is recommended to consult with a healthcare professional for a comprehensive understanding of the potential adverse effects of specific MS medications on brain plasticity.
Overall, while there is limited research specifically addressing adverse effects, current evidence suggests that some MS medications may have a positive impact on brain plasticity by reducing inflammation and promoting recovery. Further research is needed to fully understand the relationship between MS medications and brain plasticity.
Different diets can have an impact on brain plasticity, which refers to the brain's ability to change and adapt in response to experiences and environmental factors. Several studies have investigated the effects of various dietary interventions on brain plasticity markers and cognitive function.
Caloric restriction (CR) and intermittent fasting (IF) have been shown to enhance brain plasticity in animal studies. These dietary interventions have been associated with increased expression of neurotrophic factors, synaptic function, and adult neurogenesis in the hippocampus, a brain region important for learning and memory [
39]. However, more research is needed to understand the mechanisms underlying these effects and to determine their translatability to humans.
Dietary supplementation with polyphenols and polyunsaturated fatty acids (PUFAs) has also been found to impact brain plasticity. For example, docosahexaenoic acid (DHA), an omega-3 fatty acid found in fatty fish, has been shown to influence protein levels related to metabolic homeostasis and synaptic plasticity in the hypothalamus and hippocampus of rats [
40]. Additionally, DHA supplementation has been associated with improved spatial memory ability in mice [
41].
Furthermore, the consumption of dark chocolate, which contains flavonoids and other bioactive compounds, has been shown to have positive effects on brain functions. In a rat study, different dietary patterns of dark chocolate were found to reverse the harmful effects of chronic isolation stress on synaptic potency, plasticity, learning, and memory in the hippocampus [
42].
Overall, these studies suggest that different diets can modulate brain plasticity markers and cognitive function. However, more research is needed to fully understand the specific mechanisms and to determine the optimal dietary interventions for promoting brain health and function in humans.
Nutraceuticals in MS
Nutraceuticals are natural or bioactive compounds found in food or dietary supplements that have potential health benefits beyond basic nutrition. They are often used as adjunctive treatments to support overall health and well-being.
In MS, several nutraceuticals have been studied for their potential benefits. The most used nutraceuticals in MS include:
Vitamin D supplementation has been extensively studied in MS due to its role in immune regulation and its potential to reduce disease activity and progression [
56,
57,
58].
Alpha lipoic acid (ALA) is an antioxidant that has shown promise in improving clinical and biological outcomes in MS, such as reducing fatigue and improving brain volume [
59].
Ginkgo biloba has been reported to improve clinical and biological outcomes in MS, including fatigue and antioxidant capacity [
59].
Biotin supplementation has shown potential in improving clinical outcomes in MS, such as reducing disability progression and improving walking ability [
59].
Omega-3 fatty acids: Omega-3 fatty acids, found in fish oil, have anti-inflammatory properties and may help reduce inflammation in MS [
58].
A study found no significant evidence for drug interactions between conventional MS drugs and several nutraceuticals, including ginger, cranberry, vitamin D, fatty acids, turmeric, probiotics, or glucosamine [
60].
The presumed mechanisms of action of nutraceuticals in MS involve their ability to target various pathways involved in the pathogenesis of the disease (
Figure 2). Some of these mechanisms are:
Nutraceuticals such as polyunsaturated fatty acids (PUFAs), green tea flavonoids (epigallocatechin-3-gallate), curcumin, and scorpion toxins have been found to possess anti-inflammatory properties and can modulate the immune response in MS. They can inhibit pro-inflammatory signalling pathways, such as NF-κB or toll-like receptors and reduce the activity of auto-aggressive immune cells. These effects may help reduce inflammation and immune-mediated damage in MS [
56].
Oxidative stress is implicated in the pathogenesis of MS. Nutraceuticals like green tea, curcumin, and resveratrol have antioxidative properties and can scavenge free radicals, reducing oxidative damage. By reducing oxidative stress, these compounds may protect against neuronal damage and inflammation in MS [
61].
Nutraceuticals such as flavonoids, terpenoids, and polyphenols have shown potential in promoting neuroprotection and myelin repair in animal models of MS. They may support the survival and function of neurons, promote remyelination, and enhance endogenous repair processes [
62].
Epigenetic modifications play a role in MS. Some nutraceuticals, such as plant polyphenols, Ω-3 and Ω-6 polyunsaturated fatty acids, and sulphur-containing compounds, can influence gene expression through epigenetic mechanisms. These compounds may regulate the production of pro-inflammatory proteins and modulate immune responses in MS [
63].
Figure 2.
Proposed mechanisms of neurodegeneration by nutraceuticals.
Figure 2.
Proposed mechanisms of neurodegeneration by nutraceuticals.
Vitamin D3, also known as cholecalciferol, is a form of vitamin D that is synthesized in the skin when exposed to sunlight or obtained through dietary sources. It plays a crucial role in maintaining calcium and phosphate balance in the body, which is essential for bone health. However, emerging research suggests that vitamin D3 also has important roles in brain plasticity and MS [
64].
Vitamin D3 has been found to have immunomodulatory and neuroprotective effects within the central nervous system. It acts through its receptors in glial cells, such as astrocytes and microglia, to influence the production of proinflammatory cytokines and antioxidants. This modulation of neuroinflammation may help mitigate the cascade of events leading to neuronal damage. Vitamin D3 also contributes to neurogenesis and synaptic plasticity, which are important processes for brain plasticity [
65].
In the context of MS, vitamin D3 has been investigated for its potential therapeutic effects. Studies have shown that vitamin D3 supplementation may reduce disease activity and demyelination in animal models of MS. Clinical studies have also suggested that vitamin D3 deficiency is associated with an increased risk of developing MS and that supplementation may have beneficial effects on disease progression and activity [
66].
In a study on mice with EAE, an animal model of MS, early intervention with the active form of vitamin D3 (1,25-dihydroxyvitamin D3) was found to control neuroinflammation and reduce inflammation, demyelination, and oxidative stress. This suggests that vitamin D3 may have potential as an adjunct therapy for MS patients [
64].
Vitamin D3's role in modulating neuroinflammation and its potential neuroprotective effects make it an interesting target for further research and therapeutic strategies in neurodegenerative and neuropsychiatric disorders. However, more clinical studies are needed to validate these findings and fully understand the mechanisms and benefits of vitamin D3 supplementation in these conditions.
In summary, vitamin D3 plays a role in brain plasticity and has been investigated for its potential therapeutic effects in multiple sclerosis. It has immunomodulatory and neuroprotective properties that may help reduce neuroinflammation and promote neurogenesis and synaptic plasticity. However, further research is needed to fully understand the benefits and mechanisms of vitamin D3 in brain health and disease.
Immunoglobulin Y (IgY) is a type of immunoglobulin, or antibody, found in the blood of birds, reptiles, and amphibians. It is the avian equivalent of mammalian immunoglobulin G (IgG). IgY is produced by specialized cells called B lymphocytes in these animals and plays a crucial role in their immune defence against pathogens. One unique characteristic of IgY is that it is actively transported from the bloodstream into the egg yolk during egg formation. As a result, IgY is present in copious quantities in the egg yolk, providing passive immunity to the developing embryo or offspring. This is an evolutionary adaptation that allows birds and reptiles to pass on immune protection to their young before they have fully developed their own immune systems. IgY has gained attention in biomedical research and applications due to its potential as an alternative to mammalian antibodies, such as IgG. It offers several advantages, including ethical considerations (no need for animal bleeding as antibodies are extracted from eggs), cost-effectiveness (production from egg yolks), and potential therapeutic applications. Research on IgY has explored its use in various fields, including immunodiagnostics, immunotherapy, and antimicrobial applications. Studies have investigated its effectiveness in detecting and treating infectious diseases, as well as its potential in modulating immune responses and targeting specific pathogens [
67,
68].
There is limited research specifically investigating the role of IgY in MS. However, a study mentioned that IgY supplements derived from chicken egg yolk have shown potential in modulating gut microbiota and immune responses and have been effective against various infections [
69]. In terms of MS, the study mentioned that clinical trials using IgY supplements in MS are limited but have shown positive outcomes, including reduced symptoms and altered immune responses [
69]. However, further research is needed to understand the mechanisms of IgY's interaction with gut microbiota, determine optimal dosage, and assess long-term safety [
69].
Homeopathy is a form of complementary and alternative medicine (CAM) that is sometimes used by people with MS. While there is no definitive treatment for MS, management is largely focused on symptom relief. Conventional therapies may not be effective for everyone or may cause unacceptable side effects. As a result, some individuals with MS turn to CAM, including homeopathy, to help manage their symptoms. Homeopathy is a whole-person approach that allows for individualized treatment based on the specific symptoms and needs of the person with MS. It aims to stimulate the body's self-healing mechanisms by administering highly diluted substances that would produce similar symptoms in a healthy person. Homeopathic treatments for MS symptoms such as urinary incontinence, sexual dysfunction, cramps and spasms, tremor, and trigeminal neuralgia have shown some benefit in certain individuals [
70,
71,
72]. However, it is important to note that the evidence supporting the effectiveness of homeopathy in treating MS is limited. Studies on the use of homeopathy in MS have mainly focused on individual cases or small groups of patients, making it difficult to draw definitive conclusions. Additionally, the placebo effect may play a role in the perceived benefits of homeopathic treatments [
70,
71,
72].
Overall, while some individuals with MS may find relief from certain symptoms through homeopathy, more research is needed to determine its efficacy and safety in the management of MS[
12,
73].
Ginkgo biloba extract (GBE) is a plant extract derived from the leaves of the Ginkgo biloba tree. It has been used for centuries in traditional medicine and is now commonly consumed as a dietary supplement. The presumed effects of ginkgo biloba on brain plasticity are based on its potential neuroprotective and neuroregenerative properties. GBE has been shown to have antioxidant and anti-inflammatory effects, which can help protect neurons from damage and promote their survival [
74]. It has also been found to enhance cerebral blood flow and improve vascular function, which is important for delivering oxygen and nutrients to the brain [
74]. In terms of brain plasticity, GBE has been studied for its effects on synaptic plasticity, which is the ability of synapses to change and adapt in response to experience. Some studies have suggested that ginkgo biloba extract can enhance synaptic plasticity by modulating neurotransmitter pathways and promoting the release of endogenous relaxing factors [
74]. These effects may contribute to improved cognitive function and memory.
There is limited evidence on the specific effects of Ginkgo biloba on brain plasticity in MS. However, some studies have investigated the effects of GBE on cognitive function and neuroprotection in MS.
One study evaluated the effects of GBE on cognitive function in individuals with MS and found that treatment with GBE did not improve cognitive performance [
75]. Another study investigated the effects of GBE on cognitive performance in MS and found that GBE did not show a statistically significant improvement in cognitive function, except for a trend towards improvement on the Stroop test [
76].
While these studies focused on cognitive function, they did not specifically examine brain plasticity. However, GBE has been shown to have neuroprotective effects in various neurological diseases. It has been found to promote myelin generation, regulate the balance of microglia and astrocytes, and induce the generation of oligodendrocyte precursor cells, which are important for remyelination [
77]. These effects may indirectly contribute to brain plasticity in MS.
Overall, the evidence on the effects of GBE on brain plasticity in MS is limited. Further research is needed to determine the specific effects of Ginkgo biloba on brain plasticity in individuals with MS.
Alpha lipoic acid (ALA) is a natural compound with antioxidant and anti-inflammatory properties. It acts as a cofactor for mitochondrial enzymes involved in energy production and has various biological functions, including scavenging reactive oxygen species, regenerating other antioxidants, and modulating signal transduction pathways [
78].
In terms of brain plasticity, ALA has been studied for its potential neuroprotective effects after brain injury. Animal studies have shown that ALA can stimulate the synthesis of glutathione, decrease cell death, promote angiogenesis, and reduce the formation of glial scars, which allows for the formation of new neural tissue [
79]. These findings suggest that ALA may have a role in promoting brain repair and regeneration after injury.
Regarding MS, ALA has shown promise in preclinical and clinical studies. In animal models of MS, ALA has been found to reduce nerve damage, inhibit the migration of inflammatory cells, and decrease the activity of matrix metalloproteinases, which are involved in the breakdown of the blood-brain barrier [
80]. Clinical trials have demonstrated positive effects of ALA on cellular and physical outcomes in people with MS. However, more research is needed to determine the effectiveness of ALA as a therapy for MS, and it is not currently approved for this purpose [
80].
In summary, ALA has potential roles in brain plasticity by promoting neuroprotection and repair after injury. In the context of multiple sclerosis, ALA has shown promising effects in preclinical and clinical studies, but further research is needed to establish its efficacy as a therapy for MS.
Biotin, also known as vitamin B7 or vitamin H, is a water-soluble vitamin that plays a crucial role in various metabolic processes in the body. It acts as a cofactor for several carboxylase enzymes involved in energy production, fatty acid synthesis, and amino acid metabolism.
In the context of MS, there is growing interest in the potential role of high-dose biotin in preventing brain neurodegeneration.
Several studies have investigated the effects of high-dose biotin (MD1003) in patients with progressive MS. These studies have shown promising results, suggesting that biotin may have a beneficial effect on disease progression and disability improvement [
4,
81,
82,
83]. The exact mechanisms by which biotin exerts its neuroprotective effects are not fully understood, but several hypotheses have been proposed.
One hypothesis is that biotin enhances energy production in demyelinated axons, which can help support their function and prevent neurodegeneration [
60]. Biotin is involved in ATP production, which is essential for maintaining neuronal health and function [
81].
Another hypothesis is that biotin promotes myelin synthesis in oligodendrocytes, the cells responsible for producing myelin, the protective covering of nerve fibers [
60]. Biotin may enhance myelin production and repair, potentially slowing down disease progression [
84].
It is important to note that while some studies have shown positive effects of high-dose biotin in MS, not all studies have reported significant benefits [
84].
Further research is needed to fully understand the potential role of biotin in preventing brain neurodegeneration in MS and to determine the optimal dosage and treatment duration.
In summary, biotin is a vitamin that plays a role in various metabolic processes in the body. High-dose biotin has shown promise in preventing brain neurodegeneration in multiple sclerosis, potentially through its effects on energy production and myelin synthesis. However, more research is needed to confirm these findings and determine the optimal use of biotin in MS treatment.
Flavonoids are a large group of plant polyphenols that are widely distributed in the human diet. They are found in various fruits, vegetables, nuts, and beverages. Flavonoids have been studied for their potential health benefits and are believed to have several presumed effects in the human body. Flavonoids have the ability to reduce free radical formation and scavenge free radicals, which can help protect cells from oxidative damage [
85]. They can also increase the plasma antioxidant status and preserve the levels of antioxidants like vitamin E [
85]. Flavonoids have been shown to possess anti-inflammatory effects. They can modulate intracellular signaling cascades and inhibit enzymes involved in cellular activation, leading to a reduction in inflammation [
86]. Flavonoids have been associated with a lower risk of cardiovascular diseases. They have been shown to have vasodilating actions, reduce lipid peroxidation, and protect against oxidative stress, which are all beneficial for heart health [
87]. Flavonoids have immunomodulatory properties and can influence immune responses. They have been reported to possess anti-allergenic and anti-viral activities [
85].
Cognitive function: Flavonoids have been studied for their pro-cognitive effects. They can interact with major signal transduction cascades in the brain and impact transcription factors involved in neuronal function [
88].
It's important to note that the effects of flavonoids can vary depending on their specific chemical structure and concentration. Further research is needed to fully understand the mechanisms of action and potential health benefits of different flavonoids [
89].
There is limited direct evidence on the effects of flavonoids on brain plasticity specifically in MS. However, flavonoids have been shown to have neuroprotective and neuroplasticity-promoting effects in various neurological conditions.
Flavonoids have been found to exert neuroprotective effects by reducing oxidative stress and inflammation, which are key factors in MS [
90,
91]. They have also been shown to promote synaptogenesis and neurogenesis, which are important processes for brain plasticity [
90]. Additionally, flavonoids have been found to modulate signaling pathways involved in neuronal survival and synaptic plasticity [
92,
93].
In animal models of MS, flavonoids have demonstrated positive therapeutic effects. For example, the flavonoid luteolin has been shown to suppress clinical symptoms, reduce inflammation, and prevent relapse in rats with experimental autoimmune encephalomyelitis (EAE), an MS model [
94]. A systematic review of studies on EAE and MS also reported positive outcomes for the therapeutic effect of flavonoids on these conditions [
95].
While the direct effects of flavonoids on brain plasticity in MS are not well-studied, their neuroprotective and neuroplasticity-promoting properties suggest that they may have potential benefits for enhancing brain plasticity in MS. Further research is needed to explore the specific effects of flavonoids on brain plasticity in MS and to determine optimal dosages and treatment strategies (90–92,95).
Polyunsaturated fatty acids (PUFA) are a type of fat that is essential for human health and cannot be produced by the body, so they must be obtained through the diet. PUFA can be further classified into two main groups: omega-3 (n-3) and omega-6 (n-6) fatty acids.
The presumed effects of PUFA in humans are diverse and have been extensively studied. PUFA, particularly omega-3 fatty acids, have been associated with a reduced risk of cardiovascular diseases. They can help lower blood triglyceride levels, reduce inflammation, improve blood vessel function, and prevent the formation of blood clots. Omega-3 fatty acids, especially docosahexaenoic acid (DHA), play a crucial role in brain development and function. They are important for cognitive function, memory, and mood regulation. Adequate intake of omega-3 fatty acids has been linked to a lower risk of neurodegenerative diseases and improved mental health. They also provide anti-inflammatory properties. They can help reduce chronic inflammation in the body and modulate immune responses. This can be beneficial for conditions such as rheumatoid arthritis, inflammatory bowel disease, and asthma. Some studies suggest that omega-3 fatty acids may have a protective effect against certain types of cancer, such as breast, colorectal, and prostate cancer. However, more research is needed to fully understand the relationship between PUFA and cancer prevention. PUFA can influence metabolic processes, including lipid metabolism, insulin sensitivity, and glucose regulation. They may help improve insulin resistance, reduce the risk of type 2 diabetes, and prevent fatty liver disease.
It's important to note that the effects of PUFA can vary depending on the specific type and ratio of omega-3 to omega-6 fatty acids consumed, as well as individual factors such as genetics, overall diet, and health status. Therefore, it is recommended to maintain a balanced intake of both omega-3 and omega-6 fatty acids for optimal health benefits [
96,
97,
98,
99,
100,
101,
102,
103].
The effects of PUFA on brain plasticity in MS patients have been investigated in several studies. Their main effects can be concluded in:
A study on mice with induced CNS demyelination found that an increased n-3 PUFA status
promoted remyelination after toxic injury to CNS oligodendrocytes. This effect may be mediated by n-3 PUFA-derived lipid metabolites [
104].
Omega-3 PUFAs, such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have been shown to modulate microglial responses to myelin pathology. They can inhibit inflammation while
enhancing beneficial immune responses, such as microglial phagocytosis. In a mouse model of MS, n-3 PUFA supplementation reduced demyelination and shifted microglial polarization towards a beneficial phenotype [
105].
In vitro studies using oligodendroglia cells and primary oligodendrocytes have shown that supplementation with n-3 and n-6 PUFAs can promote
oligodendrocyte differentiation. This was evidenced by increased expression of markers of oligodendroglia differentiation and enhanced myelin sheet formation [
106].
A study on healthy older adults found that omega-3 PUFAs were associated with individual differences in
functional brain connectivity. Specifically, they were linked to connectivity within regions supporting executive function, memory, and emotion. These regions were also found to predict general, fluid, and crystallized intelligence [
107].
It's important to note that while these studies provide insights into the potential effects of PUFA on brain plasticity in MS patients, more research is needed to fully understand the mechanisms and clinical implications. Additionally, the optimal dosage and duration of PUFA supplementation for MS patients are still being explored.
Curcumin is a natural compound found in turmeric, a spice commonly used in cooking. It has been extensively studied for its potential health benefits. Curcumin is known for its antioxidant, anti-inflammatory, and anticancer properties. It has been shown to have diverse pharmacological effects, including neuroprotective, cardioprotective, and immunomodulatory activities. Curcumin has been investigated for its potential in the prevention and treatment of various diseases, such as cancer, cardiovascular diseases, diabetes, arthritis, neurological diseases, and gastrointestinal disorders. However, curcumin's low bioavailability has been a challenge in harnessing its full therapeutic potential [
108,
109,
110,
111,
112,
113].
There is limited research specifically investigating the effect of curcumin on brain plasticity in MS patients. However, curcumin has been shown to have beneficial effects on brain health through various mechanisms, including its antioxidant, anti-inflammatory, and neuroprotective properties. These effects may potentially contribute to the modulation of brain plasticity in MS patients. Curcumin has been studied in animal models of MS, where it has demonstrated neuroprotective effects, reduced demyelination, and improved cognitive function. Further research is needed to determine the specific impact of curcumin on brain plasticity in MS patients [
114,
115,
116].
Resveratrol is a natural compound found in various plants, including grapes, berries, peanuts, and red wine. It is a polyphenol with antioxidant, anti-inflammatory, and anti-cancer properties. Resveratrol has been studied for its potential health benefits in several areas. Resveratrol may have cardioprotective effects by improving inflammatory markers, atherogenic profile, glucose metabolism, and endothelial function [
117,
118]. It has shown promising results in preventing or delaying the development of various types of cancer, including prostate cancer by inhibiting proliferation, promoting apoptosis, and enhancing sensitivity to radiation [
119]. Also, it has been investigated for its potential in neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's diseases. It has shown effects in in vitro models, but further research is needed [
120]. Resveratrol has been associated with improved insulin sensitivity, increased energy expenditure, and a decrease in body fat [
121]. It may also have anti-obesity effects by inhibiting adipogenesis and increasing lipid mobilization [
122]. Also, it has been shown to reduce inflammation and oxidative stress in various tissues and organs [
118]. It may also have anti-angiogenic effects [
119].
It's important to note that while resveratrol has shown promising results in preclinical studies and some clinical trials, there is still a need for more research, especially in human subjects, to fully understand its effects and determine optimal doses [
123,
124]. Additionally, the bioavailability of resveratrol and its potential interactions with medications should be considered [
122].
There is limited research specifically investigating the effects of resveratrol on brain plasticity in MS patients. In an EAE mouse model of MS, resveratrol treatment was found to improve clinical outcomes and protect against optic nerve and spinal cord degeneration [
125]. Another study in cuprizone-intoxicated mice, a model of demyelination/remyelination similar to MS, showed that resveratrol enhanced motor coordination, reversed demyelination, and increased the expression of genes associated with active remyelination [
126].
While these studies suggest potential neuroprotective effects of resveratrol in MS models, it is important to note that the effects of resveratrol on brain plasticity in human MS patients have not been extensively studied. Further research is needed to determine the specific effects of resveratrol on brain plasticity in MS patients and its potential as a therapeutic intervention for MS-related neurodegenerative processes [
125].
Terpenoids are a class of naturally occurring compounds that are derived from terpenes. They are found in various plants, animals, and microorganisms. Terpenoids have diverse biological activities and are known for their pharmacological effects on the human body.
Terpenoids have been studied for their potential therapeutic benefits in various chronic illnesses. They have been found to have anti-inflammatory, antimicrobial, antifungal, antiviral, antitumor, and antioxidant properties [
127,
128,
129,
130,
131,
132,
133,
134]. They can also act as skin penetration enhancers and have been used in the prevention and treatment of inflammatory diseases [
129]. In the context of specific diseases, terpenoids have shown promise in the treatment of non-alcoholic fatty liver disease (NAFLD). They regulate lipid metabolism disorder, insulin resistance, oxidative stress, and inflammation, and target pathways such as AMPK, PPARs, Nrf-2, and SIRT 1 [
127]. Additionally, terpenoids have been explored for their potential antiviral efficacy against SARS-CoV-2, the virus responsible for COVID-19 [
15].
Furthermore, terpenoids have been investigated for their effects on psychiatric disorders. Preclinical studies have demonstrated their neuropharmacological effects and their potential as alternative therapeutic options for psychiatric disorders [
131].
Two studies provide insights into the effects of terpenoids on brain plasticity in MS patients. In a study by Tomassini et al., it was found that inflammation in MS interferes with brain plasticity [
135]. However, pharmacological reduction of inflammation, such as with Interferon beta (IFN beta) treatment, can restore brain plasticity. The study used a visuomotor adaptation task and functional MRI to assess brain plasticity in MS patients. The results showed that reduced inflammation with IFN beta treatment led to a restoration of brain plasticity, suggesting that modulation of inflammation can enhance recovery-oriented strategies that rely on brain plasticity. Similarly, Shin et al. investigated the effects of terpenes on neuronal health in Drosophila Alzheimer's disease models. They found that certain terpenes, including limonene, had neuroprotective effects against the neurotoxicity of beta amyloid 42 (Aβ42), a protein associated with AD. Limonene treatment decreased cell death, inflammation, and oxidative stress in the brains of the AD model flies. While this study was not conducted specifically in MS patients, it provides insights into the potential neuroprotective effects of terpenes on brain health [
130].
These findings suggest that terpenoids, including terpenes like limonene, may have the potential to modulate brain plasticity in MS patients by reducing inflammation, promoting neuroprotection, and enhancing recovery processes. However, it is important to note that these studies were conducted in animal models and further research is needed to determine the specific effects of terpenoids on brain plasticity in MS patients.
Polyphenols are a group of natural compounds found in a variety of plant-based foods, such as fruits, vegetables, nuts, seeds, whole grains, tea, coffee, and red wine. They are characterized by the presence of phenol structural units and are known for their antioxidant properties. The presumed effects of polyphenols in the human body are diverse and have been the subject of extensive research. Some of their potential benefits include:
Polyphenols can scavenge and neutralize harmful free radicals,
reducing oxidative stress and protecting cells from damage [
136].
Polyphenols have been studied for their potential
lipid-lowering and atheroprotective effects. They may help reduce oxidation of LDL cholesterol, improve endothelial function, lower blood pressure, and inhibit platelet aggregation [
136,
137].
Polyphenols possess
anti-inflammatory properties and can help modulate the immune system by affecting the production of cytokines and other factors involved in the immune response [
138,
139].
Polyphenols have been investigated for their potential
anti-carcinogenic effects. They may inhibit tumor growth, induce apoptosis in cancer cells, and have anti-mutagenic properties [
140].
Some polyphenols, such as resveratrol and epigallocatechin-3-gallate, have shown promise in protecting against neurodegenerative disorders by
reducing mitochondrial dysfunction and oxidative stress [
141].
There is evidence that the use of plant polyphenols, may have beneficial effects on brain plasticity in MS. For example, grape seed extract (GSE) has been shown to have neuroprotective properties and can improve brain plasticity in an EAE mouse model of MS. GSE treatment in EAE mice resulted in the correction of oxidative stress damage, restoration of antioxidant capacities, normalization of myelin protein expression, and modulation of astroglial and microglial proliferation. These effects suggest that GSE may have a positive impact on brain plasticity in MS [
142].
Sulphur-containing compounds play important roles in the human body and have various effects. Methionine, cysteine, homocysteine, and taurine are sulphur-containing amino acids. They are essential for protein synthesis and are involved in antioxidant defense mechanisms. They contribute to the synthesis of intracellular antioxidants like glutathione, which helps protect cells from oxidative damage [
143].
Glutathione and N-acetylcysteine are derivatives of sulphur-containing amino acids and act as powerful antioxidants. They help neutralize free radicals and protect cells from oxidative stress. They are also used in chelation therapy to eliminate toxic metals from the body [
143]. Naturally occurring sulphur-containing ligands can act as detoxifying agents, preventing the toxic effects of heavy and transition metal ions and aiding in their elimination from the body [
143]. Exposure to malodorous sulphur compounds has been associated with respiratory symptoms such as cough, respiratory infections, and nasal symptoms. Reduction in sulphur compound exposure has been shown to decrease the frequency of these symptoms [
144,
145]. Some sulphur compounds, such as diallyl sulphide and diallyl disulphide, have immunomodulatory effects. They can enhance white blood cell count, antibody production, and bone marrow cellularity, suggesting potential immunostimulating effects [
146]. Sulphur-containing antioxidants, such as N-acetylcysteine and lipoic acid, have been shown to reduce oxidative stress induced by substances like lead. They can help protect against oxidative damage and maintain cellular health [
147].
One study investigated the therapeutic effects of hydrogen sulfide (H2S) in a cuprizone-induced MS model in mice. The study found that treatment with a hydrogen sulfide donor (NaHS) improved locomotor coordination, reduced neuronal inflammation and demyelination, and decreased oxidative stress in the brain. These effects were associated with the downregulation of miR-146a expression and the regulation of the miR-146a/NF-κB/IL-1β axis [
148].
Another study examined the effects of sulfur dioxide (SO2) exposure on synaptic plasticity in the hippocampus of rats. The study found that exposure to SO2 at different concentrations and durations resulted in the inhibition of synaptic plasticity markers and memory-related proteins in the hippocampus. The effects of SO2 on synaptic plasticity were dependent on the duration and concentration of exposure [
149].
While these studies provide insights into the effects of sulfur compounds on brain plasticity in MS-related models, further research is needed to fully understand the mechanisms and potential therapeutic applications of sulfur compounds in MS.
Conclusions
MS presents a complex interplay of immune-mediated pathology, characterized by inflammation, demyelination, and neurodegeneration. The central nervous system (CNS) undergoes significant changes due to the disease's progression, leading to varied symptoms and disability levels among patients. Enhancing brain plasticity offers a promising avenue for mitigating these effects and improving patient outcomes.
Brain plasticity, the capacity of the brain to reorganize its structure and function, is vital for learning, memory, and recovery from injuries. In the context of MS, promoting brain plasticity can help counteract the neurological damage caused by the disease. Several mechanisms underpin brain plasticity, including synaptic modification, neurogenesis, and the activation of complex signalling pathways that support neuronal connectivity and survival.
Physical exercise is a potent modulator of brain plasticity. Aerobic exercise, resistance training, and even simple activities like walking have been shown to enhance synaptic plasticity, neurogenesis, and cognitive functions. The increased production of brain-derived neurotrophic factor (BDNF) is one key mechanism through which physical activity exerts its beneficial effects. BDNF supports the survival of existing neurons and encourages the growth and differentiation of new neurons and synapses.
Diet plays a crucial role in modulating brain health. Caloric restriction (CR) and intermittent fasting (IF) have been associated with increased expression of neurotrophic factors and enhanced synaptic function. Additionally, specific nutrients, such as omega-3 fatty acids found in fish oil, have anti-inflammatory properties that can help reduce CNS inflammation and promote brain plasticity. Polyphenols, present in foods like dark chocolate and certain fruits, also contribute to neuroprotection and cognitive enhancement.
Obesity is a known risk factor for MS progression. Controlling body weight through diet and exercise can reduce inflammation and oxidative stress, thereby supporting brain plasticity. Nutraceuticals like alpha-lipoic acid (ALA) and resveratrol have been shown to reduce oxidative damage and support metabolic homeostasis, further aiding in the control of obesity-related impacts on brain health.
Nutraceuticals are bioactive compounds that provide health benefits beyond basic nutrition. They play a significant role in supporting brain plasticity and overall brain health in MS patients.
Vitamin D3 has immunomodulatory and neuroprotective effects. It influences the production of pro-inflammatory cytokines and antioxidants, aiding in the reduction of neuroinflammation and promoting neurogenesis and synaptic plasticity. Studies have shown that vitamin D3 supplementation can reduce disease activity and progression in MS.
Omega-3 fatty acids, particularly docosahexaenoic acid (DHA), have been shown to support brain plasticity by modulating synaptic function and promoting neurogenesis. They also have anti-inflammatory properties that can help mitigate CNS inflammation in MS patients.
Antioxidants like alpha-lipoic acid (ALA) and flavonoids found in green tea and dark chocolate can scavenge free radicals, reducing oxidative stress and supporting neuroprotection. These compounds have shown potential in improving clinical outcomes in MS, including reducing fatigue and supporting cognitive functions.
Ginkgo Biloba has been reported to improve cognitive functions and reduce fatigue in MS patients. Its antioxidant capacity supports brain plasticity by protecting neurons from oxidative damage and enhancing synaptic function.
Integrating lifestyle changes and nutraceuticals into the management of MS provides a holistic approach that complements traditional pharmacological treatments. By addressing modifiable risk factors and supporting brain plasticity, patients can experience improved neurological outcomes and quality of life. Regular physical activity, a balanced diet rich in neuroprotective nutrients, and the strategic use of nutraceuticals can form a comprehensive strategy for managing MS.
Future research should focus on the long-term effects of these lifestyle modifications and nutraceuticals on brain plasticity and MS progression. Large-scale, randomized controlled trials are needed to establish definitive evidence and provide clear guidelines for clinicians. Understanding the individual variability in response to these interventions can also help tailor personalized treatment plans for MS patients.
In conclusion, the synergistic effects of lifestyle changes and nutraceuticals hold great promise for enhancing brain plasticity and improving the lives of those living with MS. By adopting these strategies, patients can take an active role in managing their condition and optimizing their neurological health.