Nutraceutical Screening in a Zebrafish Model of Muscular Dystrophy: Gingerol as a Possible Food Aid.

Duchenne muscular dystrophy (DMD), caused by mutations in the dystrophin gene, is an inherited neuromuscular disorder that causes loss of muscle mass and motor skills. In the era of genomic medicine, there is still no known cure for DMD. In clinical practice, there is a growing awareness of the possible importance of nutrition in neuromuscular diseases. This is mostly the result of patients' or caregivers' empirical reports of how active substances derived from food have led to improved muscle strength and, thus, better quality of life. In this report, we investigate several nutraceutical principles in the sapje strain of zebrafish, a validated model of DMD, in order to identify possible natural products that, if supplemented in the diet, might improve the quality of life of DMD patients. Gingerol, a constituent of fresh ginger, statistically increased the locomotion of mutant larvae and upregulated the expression of heme oxygenase 1, a target gene for therapy aimed at improving dystrophic symptoms. Although three other compounds showed a partial positive effect on locomotor and muscle structure phenotypes, our nutraceutical screening study lent preliminary support to the efficacy and safety only of gingerol. Gingerol could easily be proposed as a dietary supplement in DMD.

Recomendações nutricionais na Distrofia Muscular de Duchenne / Nutritional recommendations in Duchenne Muscular Dystrophy

OBJETIVO: Pesquisar as recomendações nutricionais para pacientes com Distrofia Muscular de Duchenne (DMD). MÉTODO: Trata- se de uma revisão integrativa da literatura, através de levantamento bibliográfico nas bases cientificas PubMed e Scielo, foram utilizadas as palavras chaves: Distrofia Muscular de Duchenne em combinação com os termos Nutrição, Nutrientes, Nutracêuticos, Vitaminas e Antioxidantes. Foi realizada a busca dos artigos publicados nos últimos 10 anos. RESULTADOS: Foram selecionados 102 artigos, dos quais após análise dos critérios de exclusão e inclusão, resultaram em 31 artigos referentes a 31,62% da amostra inicial que foram utilizados para a produção dessa revisão. CONCLUSÃO: O acompanhamento nutricional do paciente com DMD é fundamental, de forma a garantir a manutenção do estado nutricional, além de contribuir de forma significativa para a desaceleração dos sintomas da doença e melhora da qualidade de vida.

OBJECTIVE: To search for nutritional recommendations for patients with Duchenne Muscular Dystrophy (DMD). METHOD: It is an integrative review of the literature, through a bibliographic survey on the scientific bases PubMed and Scielo, the keywords used were Duchenne Muscular Dystrophy in combination with the terms Nutrition, Nutrients, Nutraceuticals, Vitamins and Antioxidants. The search was based on articles published in the last 10 years. RESULTS: A total of 102 articles were selected, of which, after analyzing the exclusion and inclusion criteria, resulted in 32 articles referring to 32.64% of the initial sample that were used to produce this review. CONCLUSION: Nutritional monitoring of patients with DMD is essential, in order to guarantee the maintenance of nutritional status, in addition to contributing significantly to the deceleration of the symptoms of the disease and improving the quality of life.

Safety issues and harmful pharmacological interactions of nutritional supplements in Duchenne muscular dystrophy: considerations for Standard of Care and emerging virus outbreaks.

At the moment, little treatment options are available for Duchenne muscular dystrophy (DMD). The absence of the dystrophin protein leads to a complex cascade of pathogenic events in myofibres, including chronic inflammation and oxidative stress as well as altered metabolism. The attention towards dietary supplements in DMD is rapidly increasing, with the aim to counteract pathology-related alteration in nutrient intake, the consequences of catabolic distress or to enhance the immunological response of patients as nowadays for the COVID-19 pandemic emergency. By definition, supplements do not exert therapeutic actions, although a great confusion may arise in daily life by the improper distinction between supplements and therapeutic compounds. For most supplements, little research has been done and little evidence is available concerning their effects in DMD as well as their preventing actions against infections. Often these are not prescribed by clinicians and patients/caregivers do not discuss the use with their clinical team. Then, little is known about the real extent of supplement use in DMD patients. It is mistakenly assumed that, since compounds are of natural origin, if a supplement is not effective, it will also do no harm. However, supplements can have serious side effects and also have harmful interactions, in terms of reducing efficacy or leading to toxicity, with other therapies. It is therefore pivotal to shed light on this unclear scenario for the sake of patients. This review discusses the supplements mostly used by DMD patients, focusing on their potential toxicity, due to a variety of mechanisms including pharmacodynamic or pharmacokinetic interactions and contaminations, as well as on reports of adverse events. This overview underlines the need for caution in uncontrolled use of dietary supplements in fragile populations such as DMD patients. A culture of appropriate use has to be implemented between clinicians and patients' groups.

Supplementation with a selective amino acid formula ameliorates muscular dystrophy in mdx mice.

Duchenne muscular dystrophy (DMD) is one of the most common and severe forms of muscular dystrophy. Oxidative myofibre content, muscle vasculature architecture and exercise tolerance are impaired in DMD. Several studies have demonstrated that nutrient supplements ameliorate dystrophic features, thereby enhancing muscle performance. Here, we report that dietary supplementation with a specific branched-chain amino acid-enriched mixture (BCAAem) increased the abundance of oxidative muscle fibres associated with increased muscle endurance in dystrophic mdx mice. Amelioration of the fatigue index in BCAAem-treated mdx mice was caused by a cascade of events in the muscle tissue, which were promoted by endothelial nitric oxide synthase (eNOS) activation and vascular endothelial growth factor (VEGF) expression. VEGF induction led to recruitment of bone marrow (BM)-derived endothelial progenitors (EPs), which increased the capillary density of dystrophic skeletal muscle. Functionally, BCAAem mitigated the dystrophic phenotype of mdx mice without inducing dystrophin protein expression or replacing the dystrophin-associated glycoprotein (DAG) complex in the membrane, which is typically lost in DMD. BCAAem supplementation could be an effective adjuvant strategy in DMD treatment.

Effects of dietary omega-3 on dystrophic cardiac and diaphragm muscles as evaluated by 1H magnetic resonance spectroscopy: Metabolic profile and calcium-related proteins.

BACKGROUND & AIMS: Duchenne muscular dystrophy (DMD) is characterized by the absence of dystrophin and muscle degeneration. Calcium dysregulation and oxidative stress also contribute to the disease progression. We evaluated the potential therapeutic benefits of supplementation with omega-3 on the metabolic profile, calcium-related proteins and oxidative stress response in the heart and diaphragm (DIA) of the mdx mouse model of DMD at later stages of the disease (13 months). METHODS: Mdx mice (8 months old) received omega-3 via a dietary supplement for 5 months. Metabolites were analyzed by 1H magnetic resonance spectroscopy. Muscle total calcium was evaluated by inductively coupled plasma-optical emission spectrometry. Calsequestrin, TRPC1 and 4-HNE were determined via Western blot. RESULTS: Omega-3 decreased the metabolites taurine (related to calcium regulation and oxidative stress), aspartate (related to inflammation) and oxypurinol (related to oxidative stress) in the heart (aspartate) and DIA (taurine, aspartate and oxypurinol). Omega-3 also significantly decreased total calcium and TRPC1 levels in cardiac and DIA muscles and increased the levels of calsequestrin (cardiac and skeletal) and decreased the oxidative stress marker 4-HNE. CONCLUSIONS: The current study suggests that supplementation with omega-3 may generate therapeutic benefits on dystrophy progression, at later stages of the disease, with changes in the metabolic profile that may be correlated to omega-3 therapy.

Nutraceuticals and Their Potential to Treat Duchenne Muscular Dystrophy: Separating the Credible from the Conjecture.

In recent years, complementary and alternative medicine has become increasingly popular. This trend has not escaped the Duchenne Muscular Dystrophy community with one study showing that 80% of caregivers have provided their Duchenne patients with complementary and alternative medicine in conjunction with their traditional treatments. These statistics are concerning given that many supplements are taken based on purely "anecdotal" evidence. Many nutraceuticals are thought to have anti-inflammatory or anti-oxidant effects. Given that dystrophic pathology is exacerbated by inflammation and oxidative stress these nutraceuticals could have some therapeutic benefit for Duchenne Muscular Dystrophy (DMD). This review gathers and evaluates the peer-reviewed scientific studies that have used nutraceuticals in clinical or pre-clinical trials for DMD and thus separates the credible from the conjecture.

Resveratrol decreases inflammation and increases utrophin gene expression in the mdx mouse model of Duchenne muscular dystrophy.

BACKGROUND & AIMS: Duchenne muscular dystrophy (DMD) is a lethal genetic disease with no cure. Reducing inflammation or increasing utrophin expression can alleviate DMD pathology. Resveratrol can reduce inflammation and activate the utrophin promoter. The aims of this study were to identify an active dose of resveratrol in mdx mice and examine if this dose decreased inflammation and increased utrophin expression. METHODS: 5-week old mdx mice were given 0, 10, 100, or 500 mg/kg of resveratrol everyday for 10 days. Sirt1 was measured by qRT-PCR and used to determine the most active dose. Muscle inflammation was measured by H&E staining, CD45 and F4/80 immunohistochemistry. IL-6, TNFα, PGC-1α, and utrophin gene expression were measured by qRT-PCR. Utrophin, Sirt1, and PGC-1α protein were quantified by western blot. RESULTS: The 100 mg/kg dose of resveratrol, the most active dose, increased Sirt1 mRNA 60 ± 10% (p < 0.01), reduced immune cell infiltration 21 ± 6% (H&E) and 42 ± 8% (CD45 immunohistochemistry (p < 0.05)), reduced macrophage infiltration 48 ± 10% (F4/80 immunohistochemistry (p < 0.05)), and increased IL-6, PGC-1α, and utrophin mRNA 247 ± 77%, 27 ± 17%, and 43 ± 23% respectively (p ≤ 0.05). Utrophin, Sirt1, and PGC-1α protein expression did not change. CONCLUSIONS: Resveratrol may be a therapy for DMD by reducing inflammation.

A review of nutrition in Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a recessive X linked genetic disorder characterised by progressive muscle weakness and reduced muscle tone. Affecting only boys, it limits life expectancy to approximately 20 years. A literature review was conducted using MEDLINE and the Cochrane Library, employing the term 'Duchenne muscular dystrophy'. A total of 1491 articles in English were recovered. These papers were searched thematically under the headings: body composition (n = 10), energy expenditure (n = 10), nutrition (n = 6), corticosteroid therapy (n = 55) and gene therapy (n = 199). Key dietetic practice points were identified relevant to nutritional management. Papers supporting these key themes were assigned a level of evidence and grade of recommendation. There is limited high-quality evidence to guide the nutritional management of boys with DMD. Currently, the majority of evidence is based on expert opinion and clinical expertise. Delayed growth, short stature, muscle wasting and increased fat mass are characteristics of DMD and impact on nutritional status and energy requirements. The early introduction of steroids has altered the natural history of the disease, but can exacerbate weight gain in a population already susceptible to obesity. Prior to commencing steroids, anticipatory guidance for weight management should be provided. Malnutrition is a feature of end stage disease requiring a multidisciplinary approach, such as texture modification and supplemental feeding. Micronutrient requirements are yet to be determined but, as a result of corticosteroid treatment, vitamin D and calcium should be supplemented. Some evidence exists supporting supplementation with creatine monohydrate to improve muscle strength. More research is needed to provide a higher quality of evidence for dietitians working within this area.

Duchenne muscular dystrophy: focus on pharmaceutical and nutritional interventions.

Duchenne muscular dystrophy is a lethal X-linked muscle disease resulting from a defect in the muscle membrane protein dystrophin. The absence of dystrophin leads to muscle membrane fragility, muscle death (necrosis) and eventual replacement of skeletal muscle by fat and fibrous connective tissue. Extensive muscle wasting and respiratory failure results in premature death often by the early 20s. This short review evaluates drug and nutritional interventions designed to reduce the severity of muscular dystrophy, while awaiting the outcome of research into therapies to correct the fundamental gene defect. Combinations of dietary supplementation with amino-acids such as creatine, specific anti-inflammatory drugs and perhaps drugs that target ion channels might have immediate realistic clinical benefits although rigorous research is required to determine optimal combinations of such interventions.

Nutritional therapy improves function and complements corticosteroid intervention in mdx mice.

Corticosteroid therapy for Duchenne muscular dystrophy is effective but associated with long-term side effects. To determine the potential therapeutic benefit from four nutritional compounds (creatine monohydrate, conjugated linoleic acid, alpha-lipoic acid, and beta-hydroxy-beta-methylbutyrate) alone, in combination, and with corticosteroids (prednisolone), we evaluated the effects on several variables in exercising mdx mice. Outcome measures included grip strength, rotarod performance, serum creatine kinase levels, muscle metabolites, internalized myonuclei, and retroperitoneal fat pad weight. In isolation, each nutritional treatment showed some benefit, with the combination therapy showing the most consistent benefits. Prednisolone and the combination therapy together provided the most consistent evidence of efficacy; increased peak grip strength (P < 0.05), decreased grip strength fatigue (P < 0.05), decreased number of internalized myonuclei (P < 0.01), and smaller retroperitoneal fat pad stores (P < 0.001). This study provided evidence for therapeutic benefit from a four-compound combination therapy alone, and in conjunction with corticosteroids in the mdx model of DMD.

Dietary NaCl supplementation prevents muscle necrosis in a mouse model of Duchenne muscular dystrophy.

The mdx mouse is an animal model for Duchenne muscular dystrophy. Mdx mice fed a 12% NaCl diet from birth up to 20 days of age (mdx-Na mice) had an approximately 50% reduction in serum creatine kinase (CK) activity compared with mdx mice fed a standard diet. Most notably, necrotic fibers in tibialis anterior (TA) muscle of mdx-Na mice were reduced by 99% and were similar in control mice. These mdx mice displayed significantly elevated blood Ca2+ and Na+ levels, while the total calcium content of their TA muscle was reduced to the level of control mice. In addition, mdx-Na mice had elevated zinc and magnesium contents in their TA muscle. These results suggest that elevated serum Na+ leads to Ca2+ extrusion from muscle via the Na+/Ca2+ exchanger causing a decrease in intracellular Ca2+ levels and an increase in blood Ca2+ levels. Extracellular Ca2+ and, in addition, Zn2+ and Mg2+ might also contribute to the stabilization of the cell membrane. Other possibilities explaining the surprisingly efficacious beneficial effect of dietary sodium exist and are discussed.