Improvement of endurance of DMD animal model using natural polyphenols

Exploring the Gut Microbiota-Muscle Axis in Duchenne Muscular Dystrophy

The gut microbiota plays a pivotal role in maintaining the dynamic balance of intestinal epithelial and immune cells, crucial for overall organ homeostasis. Dysfunctions in these intricate relationships can lead to inflammation and contribute to the pathogenesis of various diseases. Recent findings uncovered the existence of a gut-muscle axis, revealing how alterations in the gut microbiota can disrupt regulatory mechanisms in muscular and adipose tissues, triggering immune-mediated inflammation. In the context of Duchenne muscular dystrophy (DMD), alterations in intestinal permeability stand as a potential origin of molecules that could trigger muscle degeneration via various pathways. Metabolites produced by gut bacteria, or fragments of bacteria themselves, may have the ability to migrate from the gut into the bloodstream and ultimately infiltrate distant muscle tissues, exacerbating localized pathologies. These insights highlight alternative pathological pathways in DMD beyond the musculoskeletal system, paving the way for nutraceutical supplementation as a potential adjuvant therapy. Understanding the complex interplay between the gut microbiota, immune system, and muscular health offers new perspectives for therapeutic interventions beyond conventional approaches to efficiently counteract the multifaceted nature of DMD.

Flavonoids and Omega3 Prevent Muscle and Cardiac Damage in Duchenne Muscular Dystrophy Animal Model

Nutraceutical products possess various anti-inflammatory, antiarrhythmic, cardiotonic, and antioxidant pharmacological activities that could be useful in preventing oxidative damage, mainly induced by reactive oxygen species. Previously published data showed that a mixture of polyphenols and polyunsaturated fatty acids, mediate an antioxidative response in mdx mice, Duchenne muscular dystrophy animal model. Dystrophic muscles are characterized by low regenerative capacity, fibrosis, fiber necrosis, inflammatory process, altered autophagic flux and inadequate anti-oxidant response. FLAVOmega β is a mixture of flavonoids and docosahexaenoic acid. In this study, we evaluated the role of these supplements in the amelioration of the pathological phenotype in dystrophic mice through in vitro and in vivo assays. FLAVOmega β reduced inflammation and fibrosis, dampened reactive oxygen species production, and induced an oxidative metabolic switch of myofibers, with consequent increase of mitochondrial activity, vascularization, and fatigue resistance. Therefore, we propose FLAVOmega β as food supplement suitable for preventing muscle weakness, delaying inflammatory milieu, and sustaining physical health in patients affected from DMD.

An Overview of Physical Exercise and Antioxidant Supplementation Influences on Skeletal Muscle Oxidative Stress

One of the essential injuries caused by moderate to high-intensity and short-duration physical activities is the overproduction of reactive oxygen species (ROS), damaging various body tissues such as skeletal muscle (SM). However, ROS is easily controlled by antioxidant defense systems during low to moderate intensity and long-term exercises. In stressful situations, antioxidant supplements are recommended to prevent ROS damage. We examined the response of SM to ROS generation during exercise using an antioxidant supplement treatment strategy in this study. The findings of this review research are paradoxical due to variances in antioxidant supplements dose and duration, intensity, length, frequency, types of exercise activities, and, in general, the lack of a regular exercise and nutrition strategy. As such, further research in this area is still being felt.

Nitric Oxide (NO) and Duchenne Muscular Dystrophy: NO Way to Go?

The discordance between pre-clinical success and clinical failure of treatment options for Duchenne Muscular Dystrophy (DMD) is significant. The termination of clinical trials investigating the phosphodiesterase inhibitors, sildenafil and tadalafil (which prolong the second messenger molecule of nitric oxide (NO) signaling), are prime examples of this. Both attenuated key dystrophic features in the mdx mouse model of DMD yet failed to modulate primary outcomes in clinical settings. We have previously attempted to modulate NO signaling via chronic nitrate supplementation of the mdx mouse but failed to demonstrate beneficial modulation of key dystrophic features (i.e., metabolism). Instead, we observed increased muscle damage and nitrosative stress which exacerbated MD. Here, we highlight that acute nitrite treatment of human DMD myoblasts is also detrimental and suggest strategies for moving forward with NO replacement therapy in DMD.

Preliminary Evidences of Safety and Efficacy of Flavonoids- and Omega 3-Based Compound for Muscular Dystrophies Treatment: A Randomized Double-Blind Placebo Controlled Pilot Clinical Trial

Background: Nutritional compounds can exert both anti-inflammatory and anti-oxidant effects. Since these events exacerbate the pathophysiology of muscular dystrophies, we investigated nutraceutical supplementation as an adjuvant therapy in dystrophic patients, to low costs and easy route of administration. Moreover, this treatment could represent an alternative therapeutic strategy for dystrophic patients who do not respond to corticosteroid treatment.

Objective: A 24 weeks randomized double-blind placebo-controlled clinical study was aimed at evaluating the safety and efficacy of daily oral administration of flavonoids- and omega3-based natural supplement (FLAVOMEGA) in patients affected by muscular dystrophy with recognized muscle inflammation.

Design: We screened 60 patients diagnosed for Duchenne (DMD), Facioscapulohumeral (FSHD), and Limb Girdle Muscular Dystrophy (LGMD). Using a computer-generated random allocation sequence, we stratified patients in a 2:1:1 ratio (DMD:FSHD:LGMD) to one of two treatment groups: continuous FLAVOMEGA, continuous placebo. Of 29 patients included, only 24 completed the study: 15 were given FLAVOMEGA, 14 placebo.

Results: FLAVOMEGA was well tolerated with no reported adverse events. Significant treatment differences in the change from baseline in 6 min walk distance (6MWD; secondary efficacy endpoint) (P = 0.033) and in isokinetic knee extension (P = 0.039) (primary efficacy endpoint) were observed in LGMD and FSHD subjects. Serum CK levels (secondary efficacy endpoint) decreased in all FLAVOMEGA treated groups with significant difference in DMD subjects (P = 0.039).

Conclusions: Although the small number of patients and the wide range of disease severity among patients reduced statistical significance, we obtained an optimal profile of safety and tolerability for the compound, showing valuable data of efficacy in primary and secondary endpoints.

Trial registration number: NCT03317171

Retrospectively registered 25/10/2017

Fibrosis Rescue Improves Cardiac Function in Dystrophin-Deficient Mice and Duchenne Patient-Specific Cardiomyocytes by Immunoproteasome Modulation

Patients affected by Duchenne muscular dystrophy (DMD) develop a progressive dilated cardiomyopathy characterized by inflammatory cell infiltration, necrosis, and cardiac fibrosis. Standard treatments consider the use of β-blockers and angiotensin-converting enzyme inhibitors that are symptomatic and unspecific toward DMD disease. Medications that target DMD cardiac fibrosis are in the early stages of development. We found immunoproteasome dysregulation in affected hearts of mdx mice (murine animal model of DMD) and cardiomyocytes derived from induced pluripotent stem cells of patients with DMD. Interestingly, immunoproteasome inhibition ameliorated cardiomyopathy in mdx mice and reduced the development of cardiac fibrosis. Establishing the immunoproteasome inhibition-dependent cardioprotective role suggests the possibility of modulating the immunoproteasome as new and clinically relevant treatment to rescue dilated cardiomyopathy in patients with DMD.

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 Geniposide from Gardenia Fruit Pomace on Skeletal-Muscle Fibrosis

Geniposide is the main bioactive constituent of gardenia fruit. Skeletal-muscle fibrosis is a common and irreversibly damaging process. Numerous studies have shown that geniposide could improve many chronic diseases, including metabolic syndrome and tumors. However, the effects of geniposide on skeletal-muscle fibrosis are still poorly understood. Here, we found that crude extracts of gardenia fruit pomace could significantly decrease the expression of profibrotic genes in vitro. Moreover, geniposide could also reverse profibrotic-gene expression induced by TGF-β and Smad4, a regulator of skeletal-muscle fibrosis. In addition, geniposide treatment could significantly downregulate profibrotic-gene expression and improve skeletal-muscle injuries in a mouse model of contusion. These results together suggest that geniposide has an antifibrotic effect on skeletal muscle through the suppression of the TGF-β-Smad4 signaling pathway.