Effects of Curcumin on Muscle Strength Improvement

This article investigates the effects of curcumin on improving muscle strength, preventing damage to oligodendrocytes and myelin in the brain, and studying its impact in an animal model of multiple sclerosis (MS).

Introduction to Multiple Sclerosis (MS)

Multiple sclerosis (MS) is one of the most common neurodegenerative diseases. During this disease, the body’s immune system attacks oligodendrocytes and the myelin sheath of neurons in the central nervous system. This condition leads to disruptions in nerve signal conduction, causing symptoms such as:

• Weakness and fatigue
• Visual and motor disturbances
• Tremors
• Ataxia
• Bladder dysfunction
• Depression
• Cognitive impairment

Main Mechanism of Disability Development

The progressive destruction of myelin due to apoptosis of oligodendrocytes, which occurs following localized inflammation in the nervous system, is one of the main mechanisms responsible for these disabilities.

Prevalence of the Disease

The prevalence of MS is approximately 120 cases per 100,000 people. The rate of occurrence is twice as high in women compared to men. MS predominantly affects young adults aged between 20 and 40 years, while the incidence is lower in children and the elderly. The exact cause of MS remains unknown, but factors such as:

• Genetics
• Environment
• Immunological aspects

play a role in its development.

New Treatment Methods

Due to the production of inflammatory factors and anti-myelin antibodies, most researchers consider MS to be an autoimmune disease. Therefore, the treatment of MS usually relies on using immunosuppressive agents and reducing inflammation in the nervous system. Immunosuppressive treatment, however, exposes MS patients to other infectious and viral diseases. As a result, the use of new therapies, such as stem cell therapy and supplementary compounds, is essential.

Introduction to Curcumin

Recently, the use of herbal medicine to advance therapeutic goals in neurodegenerative diseases has gained particular attention. Among these, curcumin, the main component of turmeric, has been highlighted. This plant has relatively low inherent toxicity, and its medicinal properties have been widely reported, including its potent antioxidant and neuroprotective effects in neurodegenerative diseases such as:

• Alzheimer’s disease
• Parkinson’s disease
• Epilepsy

How Does Curcumin Work?

Curcumin can play a significant role in treating MS by inhibiting the activity and secretion of interferon-gamma and reducing lymphocyte-activating factors.

Effects of Nano-Curcumin Polymerase

Studies using nano-curcumin polymerase have shown that this compound can pass the blood-brain barrier, balance the expression of pro-inflammatory and anti-inflammatory genes, and reduce oxidative stress, leading to a reduction in inflammation and improvement of the myelin repair process in the spinal cord.

Curcumin’s Mechanisms of Action

In summary, curcumin reduces neuronal and neuroglial apoptosis and improves neuroprotection in neurodegenerative diseases through the following mechanisms:

• Inhibition of migration
• Microglial activation
• Generation of a specific microglial phenotype with anti-inflammatory properties
• Neuroprotection
• Reduction of nitric oxide synthesis and caspase 3 activity
• Improvement in mitochondrial function
• Increase in myelin sheath numbers

Curcumin’s Effect on Myelin Tissue Damage Prevention

Since the effect of curcumin on preventing damage to oligodendrocytes and myelin tissue in a toxic model of MS has not been studied, this study explores curcumin’s role in preventing damage to oligodendrocyte precursor cells and mature oligodendrocytes in the brain of rats using the cuprizone MS model. Apoptosis of oligodendrocytes and progressive myelin damage are considered key mechanisms in the development of neurological problems in MS patients. Recently, plant compounds like curcumin have attracted attention for their potential in preventing and treating neurodegenerative diseases.

Study Methodology

A total of 28 rats (200 mg) were randomly assigned to four groups:

• Control
• Sham (DMSO)
• Cuprizone
• Curcumin

In the curcumin group, cuprizone (0.6%) and curcumin (200 mg/kg) were administered together for four weeks. During the study, muscle strength was assessed using the basket test, the percentage of cells expressing the markers 5 A2B and MBP were evaluated by immunohistochemistry, and myelin density was assessed using Luxol Fast Blue staining.

Study Results

Cuprizone, a copper chelator, is capable of inducing oligodendrocyte death. Four weeks after cuprizone administration, immunohistochemical analysis revealed a significant reduction in oligodendrocyte precursor and mature cells in the cuprizone and sham groups. Cuprizone is known to induce apoptosis through mechanisms such as oxidative and nitrosative stress.

How Does Cuprizone Work?

Cuprizone induces apoptosis by reducing superoxide dismutase activity and increasing nitric oxide levels. This leads to a decrease in mature oligodendrocyte populations. These results align with a study from 2001, where it was shown that cuprizone administration could cause oligodendrocyte death, especially in mature cells. Furthermore, after discontinuing cuprizone, a significant increase in oligodendrocyte precursor cells was observed. Curcumin, a polyphenolic compound, has preventive and therapeutic properties against various neurodegenerative diseases.

Effects of Cuprizone

This study demonstrated that curcumin mitigates the destructive effects of cuprizone on oligodendrocytes. Immunofluorescence analysis showed that curcumin treatment resulted in significantly higher levels of oligodendrocyte precursor cells (A2B5) and mature oligodendrocytes (Olig2) compared to cuprizone and sham groups.

Curcumin’s Mechanisms

Curcumin’s ability to pass the blood-brain barrier allows it to reduce oxidative stress and protect oligodendrocytes from death by increasing glutathione levels.

Nitric Oxide Reduction

Furthermore, researchers have shown that curcumin reduces nitric oxide levels, thereby decreasing oligodendrocyte apoptosis. In contrast, many other studies suggest curcumin may induce apoptosis in certain circumstances.

Pro- and Antioxidant Effects

Curcumin exhibits dual pro- and antioxidant effects, which may contribute to its effectiveness in treating various diseases. Cuprizone can also increase microglial activation and induce apoptosis in oligodendrocytes through other mechanisms.

Apoptotic Effects of Cuprizone

The study confirmed that curcumin can reduce the apoptotic effects of cuprizone. Cuprizone triggers inflammation and oligodendrocyte death by stimulating interleukins such as CD3 and IL-17. Thus, the observed reduction in oligodendrocyte levels in cuprizone and sham groups could be attributed to the inflammatory effects of cuprizone. The number of oligodendrocytes was higher in the curcumin group.

Reducing Enzyme Activity with Curcumin

Curcumin inhibits the activity of enzymes such as cyclooxygenase-2 and lipoxygenase, decreases the production of TNF-α, and reduces the production of interleukins, which help to suppress inflammation and prevent oligodendrocyte death.

Experimental Model of Encephalomyelitis

A 2010 study on an encephalomyelitis model showed that curcumin significantly reduced serum levels of IL-17, IL-6, and IL-21, decreasing disease severity and inflammatory cell infiltration into nervous tissue. Histological analysis with Luxol Fast Blue staining showed that curcumin could prevent myelin destruction and improve sensory-motor function. Muscle strength in the cuprizone and sham groups began to significantly decrease from the third week, likely due to oligodendrocyte death and myelin damage. The curcumin group showed little change in muscle strength, likely due to curcumin’s neuroprotective effects.

Conclusion

Given the beneficial effects of curcumin in promoting oligodendrocyte survival, preventing myelin degradation, and improving sensory-motor function, as well as its anti-inflammatory, anti-apoptotic effects, and ability to cross the blood-brain barrier, curcumin is recommended for the diet of MS patients or those at risk of developing the disease.

References Bagheri E, Marandi S M, Ghasemi N. Evaluation of curcumin effects on improvement of muscle strength, prevention of oligodendrocytes and myelin damage in brain, in an animal model of multiple sclerosis (MS). SJKU 2018; 23 (5):55-64.