Ginsenoside Rg3 protects glucocorticoid‑induced muscle atrophy in vitro through improving mitochondrial biogenesis and myotube growth

Nutritional Strategies for Muscle Atrophy: Current Evidence and Underlying Mechanisms

Skeletal muscle can undergo detrimental changes in various diseases, leading to muscle dysfunction and atrophy, thus severely affecting people's lives. Along with exercise, there is a growing interest in the potential of nutritional support against muscle atrophy. This review provides a brief overview of the molecular mechanisms driving skeletal muscle atrophy and summarizes recent advances in nutritional interventions for preventing and treating muscle atrophy. The nutritional supplements include amino acids and their derivatives (such as leucine, β-hydroxy, β-methylbutyrate, and creatine), various antioxidant supplements (like Coenzyme Q10 and mitoquinone, resveratrol, curcumin, quercetin, Omega 3 fatty acids), minerals (such as magnesium and selenium), and vitamins (such as vitamin B, vitamin C, vitamin D, and vitamin E), as well as probiotics and prebiotics (like Lactobacillus, Bifidobacterium, and 1-kestose). Furthermore, the study discusses the impact of a combined approach involving nutritional support and physical therapy to prevent muscle atrophy, suggests appropriate multi-nutritional and multi-modal interventions based on individual conditions to optimize treatment outcomes, and enhances the recovery of muscle function for patients. By understanding the molecular mechanisms behind skeletal muscle atrophy and implementing appropriate interventions, it is possible to enhance the recovery of muscle function and improve patients' quality of life.

Ashwagandha Ethanol Extract Attenuates Sarcopenia-Related Muscle Atrophy in Aged Mice

The investigation focused on the impact of Withania somnifera (ashwagandha) extract (WSE) on age-related mechanisms affecting skeletal muscle sarcopenia-related muscle atrophy in aged mice. Beyond evaluating muscular aspects, the study explored chronic low-grade inflammation, muscle regeneration, and mitochondrial biogenesis. WSE administration, in comparison to the control group, demonstrated no significant differences in body weight, diet, or water intake, affirming its safety profile. Notably, WSE exhibited a propensity to reduce epidermal and abdominal fat while significantly increasing muscle mass at a dosage of 200 mg/kg. The muscle-to-fat ratio, adjusted for body weight, increased across all treatment groups. WSE administration led to a reduction in the pro-inflammatory cytokines TNF-α and IL-1β, mitigating inflammation-associated muscle atrophy. In a 12-month-old mouse model equivalent to a 50-year-old human, WSE effectively preserved muscle strength, stabilized grip strength, and increased muscle tissue weight. Positive effects were observed in running performance and endurance. Mechanistically, WSE balanced muscle protein synthesis/degradation, promoted fiber differentiation, and enhanced mitochondrial biogenesis through the IGF-1/Akt/mTOR pathway. This study provides compelling evidence for the anti-sarcopenic effects of WSE, positioning it as a promising candidate for preventing sarcopenia pending further clinical validation.

Therapeutic applications of ginseng for skeletal muscle-related disorder management

Skeletal muscle (SM) is the largest organ of the body and is largely responsible for the metabolism required to maintain body functions. Furthermore, the maintenance of SM is dependent on the activation of muscle satellite (stem) cells (MSCs) and the subsequent proliferation and fusion of differentiating myoblasts into mature myofibers (myogenesis). Natural compounds are being used as therapeutic options to promote SM regeneration during aging, muscle atrophy, sarcopenia, cachexia, or obesity. In particular, ginseng-derived compounds have been utilized in these contexts, though ginsenoside Rg1 is mostly used for SM mass management. These compounds primarily function by activating the Akt/mTOR signaling pathway, upregulating myogenin and MyoD to induce muscle hypertrophy, downregulating atrophic factors (atrogin1, muscle ring-finger protein-1, myostatin, and mitochondrial reactive oxygen species production), and suppressing the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cachexia. Ginsenoside compounds are also used for obesity management, and their anti-obesity effects are attributed to peroxisome proliferator activated receptor gamma (PPARγ) inhibition, AMPK activation, glucose transporter type 4 (GLUT4) translocation, and increased phosphorylations of insulin resistance (IR), insulin receptor substrate-1 (IRS-1), and Akt. This review was undertaken to provide an overview of the use of ginseng-related compounds for the management of SM-related disorders.

Therapeutic Applications of Ginseng Natural Compounds for Health Management

Ginseng is usually consumed as a daily food supplement to improve health and has been shown to benefit skeletal muscle, improve glucose metabolism, and ameliorate muscle-wasting conditions, cardiovascular diseases, stroke, and the effects of aging and cancers. Ginseng has also been reported to help maintain bone strength and liver (digestion, metabolism, detoxification, and protein synthesis) and kidney functions. In addition, ginseng is often used to treat age-associated neurodegenerative disorders, and ginseng and ginseng-derived natural products are popular natural remedies for diseases such as diabetes, obesity, oxidative stress, and inflammation, as well as fungal, bacterial, and viral infections. Ginseng is a well-known herbal medication, known to alleviate the actions of several cytokines. The article concludes with future directions and significant application of ginseng compounds for researchers in understanding the promising role of ginseng in the treatment of several diseases. Overall, this study was undertaken to highlight the broad-spectrum therapeutic applications of ginseng compounds for health management.

The anti-aging mechanism of ginsenosides with medicine and food homology

With the acceleration of global aging and the rise in living standards, the achievement of healthy aging is becoming an imperative issue globally. Ginseng, a medicinal plant that has a long history of dietary intake and remarkable medicinal value, has become a research hotspot in the field of food and medicine. Ginsenosides, especially protopanaxadiol-type saponins and protopanaxatriol-type saponins, are among the most important active ingredients in ginseng. Ginsenosides have been found to exhibit powerful and diverse pharmacological activities, such as antiaging, antitumor, antifatigue and immunity enhancement activities. Their effects in antiaging mainly include (1) promotion of metabolism and stem cell proliferation, (2) protection of skin and nerves, (3) modulation of intestinal flora, (4) maintenance of mitochondrial function, and (5) enhancement of telomerase activity. The underlying mechanisms are primarily associated with the intervention of the signaling pathways in apoptosis, inflammation and oxidative stress. In this review, the mechanism of action of ginsenosides in antiaging as well as the potential values of developing ginsenoside-based functional foods and antiaging drugs are discussed.

Ginsenoside Rc, an Active Component of Panax ginseng, Alleviates Oxidative Stress-Induced Muscle Atrophy via Improvement of Mitochondrial Biogenesis

Loss of skeletal muscle mass and function has detrimental effects on quality of life, morbidity, and mortality, and is particularly relevant in aging societies. The enhancement of mitochondrial function has shown promise in promoting muscle differentiation and function. Ginsenoside Rc (gRc), a major component of ginseng, has various pharmacological activities; however, its effect on muscle loss remains poorly explored. In this study, we examined the effects of gRc on the hydrogen peroxide (H2O2)-induced reduction of cell viability in C2C12 myoblasts and myotubes and H2O2-induced myotube degradation. In addition, we investigated the effects of gRc on the production of intracellular reactive oxygen species (ROS) and mitochondrial superoxide, ATP generation, and peroxisome proliferator-activated receptor-gamma co-activator 1α (PGC-1α) activity in myoblasts and myotubes under H2O2 treatment. Furthermore, to elucidate the mechanism of action of gRc, we conducted a transcriptome analysis of myotubes treated with or without gRc under H2O2 treatment. gRc effectively suppressed H2O2-induced cytotoxicity, intracellular ROS, and mitochondrial superoxide production, restored PGC-1α promoter activity, and increased ATP synthesis. Moreover, gRc significantly affected the expression levels of genes involved in maintaining mitochondrial mass and biogenesis, while downregulating genes associated with muscle degradation in C2C12 myotubes under oxidative stress. We provide compelling evidence supporting the potential of gRc as a promising treatment for muscle loss and weakness. Further investigations of the pharmacological effects of gRc under various pathological conditions of muscle loss will contribute to the clinical development of gRc as a therapeutic intervention.

Mitochondrial dysfunction: roles in skeletal muscle atrophy

Mitochondria play important roles in maintaining cellular homeostasis and skeletal muscle health, and damage to mitochondria can lead to a series of pathophysiological changes. Mitochondrial dysfunction can lead to skeletal muscle atrophy, and its molecular mechanism leading to skeletal muscle atrophy is complex. Understanding the pathogenesis of mitochondrial dysfunction is useful for the prevention and treatment of skeletal muscle atrophy, and finding drugs and methods to target and modulate mitochondrial function are urgent tasks in the prevention and treatment of skeletal muscle atrophy. In this review, we first discussed the roles of normal mitochondria in skeletal muscle. Importantly, we described the effect of mitochondrial dysfunction on skeletal muscle atrophy and the molecular mechanisms involved. Furthermore, the regulatory roles of different signaling pathways (AMPK-SIRT1-PGC-1α, IGF-1-PI3K-Akt-mTOR, FoxOs, JAK-STAT3, TGF-β-Smad2/3 and NF-κB pathways, etc.) and the roles of mitochondrial factors were investigated in mitochondrial dysfunction. Next, we analyzed the manifestations of mitochondrial dysfunction in muscle atrophy caused by different diseases. Finally, we summarized the preventive and therapeutic effects of targeted regulation of mitochondrial function on skeletal muscle atrophy, including drug therapy, exercise and diet, gene therapy, stem cell therapy and physical therapy. This review is of great significance for the holistic understanding of the important role of mitochondria in skeletal muscle, which is helpful for researchers to further understanding the molecular regulatory mechanism of skeletal muscle atrophy, and has an important inspiring role for the development of therapeutic strategies for muscle atrophy targeting mitochondria in the future.

Down-regulated Smyd1 participated in the inhibition of myoblast differentiation induced by cigarette smoke extract

The histone methyltransferase Smyd1 is essential for muscle development; however, its role in smoking-induced skeletal muscle atrophy and dysfunction has not been investigated thus far. In this study, Smyd1 was overexpressed or knocked down in C2C12 myoblasts by an adenovirus vector and cultured in differentiation medium containing 5% cigarette smoke extract (CSE) for 4 days. CSE exposure resulted in inhibition of C2C12 cell differentiation and downregulation of Smyd1 expression, whereas Smyd1 overexpression reduced the degree of inhibition of myotube differentiation caused by CSE exposure. CSE exposure activated P2RX7-mediated apoptosis and pyroptosis, caused increased intracellular reactive oxygen species (ROS) levels, and impaired mitochondrial biogenesis and increased protein degradation by downregulating PGC1α, whereas Smyd1 overexpression partially restored the altered protein levels caused by CSE exposure. Smyd1 knockdown alone produced a phenotype similar to CSE exposure, and Smyd1 knockdown during CSE exposure aggravated the degree of inhibition of myotube differentiation and the degree of activation of P2RX7. CSE exposure suppressed H3K4me2 expression, and chromatin immunoprecipitation confirmed the transcriptional regulation of P2rx7 by H3K4me2 modification. Our findings suggest that CSE exposure mediates C2C12 cell apoptosis and pyroptosis through the Smyd1-H3K4me2-P2RX7 axis, and inhibits PGC1α expression to impair mitochondrial biosynthesis and increase protein degradation by inhibiting Smyd1 expression, ultimately leading to abnormal C2C12 myoblasts differentiation and impaired myotube formation.

Physiactisome: A New Nanovesicle Drug Containing Heat Shock Protein 60 for Treating Muscle Wasting and Cachexia

Currently, no commercially available drugs have the ability to reverse cachexia or counteract muscle wasting and the loss of lean mass. Here, we report the methodology used to develop Physiactisome—a conditioned medium released by heat shock protein 60 (Hsp60)—overexpressing C2C12 cell lines enriched with small and large extracellular vesicles. We also present evidence supporting its use in the treatment of cachexia. Briefly, we obtain a nanovesicle-based secretion by genetically modifying C2C12 cell lines with an Hsp60-overexpressing plasmid. The secretion is used to treat naïve C2C12 cell lines. Physiactisome activates the expression of PGC-1α isoform 1, which is directly involved in mitochondrial biogenesis and muscle atrophy suppression, in naïve C2C12 cell lines. Proteomic analyses show Hsp60 localisation inside isolated nanovesicles and the localisation of several apocrine and merocrine molecules, with potential benefits for severe forms of muscle atrophy. Considering that Physiactisome can be easily obtained following tissue biopsy and can be applied to autologous muscle stem cells, we propose a potential nanovesicle-based anti-cachexia drug that could mimic the beneficial effects of exercise. Thus, Physiactisome may improve patient survival and quality of life. Furthermore, the method used to add Hsp60 into nanovesicles can be used to deliver other drugs or active proteins to vesicles.