A Systematic Review on the Effects of Botanicals on Skeletal Muscle Health in Order to Prevent Sarcopenia

Potentialities of Tannase-Treated Green Tea Extract in Nutraceutical and Therapeutic Applications

Green tea has garnered widespread interest in the past decades due to its content of health-beneficial polyphenols and catechins, besides reportedly exhibiting activities for the prevention, and possibly treatment, of many modern-life-associated afflictions. Hence, the functional food potential of health-beneficial beverages such as green tea is widely and commercially promoted. Biotransformation of green tea extract using enzymes such as tannase ostensibly enhances its beneficial well-being properties and disease-preventing functionalities. The tannase-treated green tea catechins may exhibit enhanced, amongst others, antioxidant, anti-tumour, anti-wrinkle, anti-inflammatory, anti-obesity and anti-sarcopenia properties compared to native green tea extract. Nonetheless, the health benefits and therapeutic and toxicological effects associated with these compounds, before and after tannase treatment, present a scientific gap for detailed studies. Accordingly, the review surveys the literature from the late twentieth century until the year 2023 related to the aforementioned important aspects.

Content of amino acids and biogenic amines in stored meat as a result of a broiler diet supplemented with β-alanine and garlic extract

Poultry meat is a highly esteemed product among consumers. However, the emphasis on increasing body weight has led to a rise in the proportion of rapidly shrinking fibers, adversely affecting the quality and shelf life of poultry meat. With a growing awareness of dietetics among consumers, there is an increasing challenge to produce chicken meat that is not only free of antibiotics but also beneficial for dietary and health reasons. Biogenic amines (BA) can serve as indicators of meat freshness and quality. While they play vital roles in the body, excessive consumption of BA can have toxic and carcinogenic effects. The objective of this study was to examine the impact of supplementing feed with garlic extract and β-alanine (β-Ala) on the formation of BA and amino acid (AA) levels in the breast and leg muscles of chickens stored under aerobic chilling conditions. The muscles were obtained from chickens fed with garlic extract and β-Ala in quantities of 0.5 and 2% for each additive, as well as 0.5 and 2% of their combination. Analyses were conducted on d 1, 3, 5, 7, and 10 of storage. β-Ala supplementation increased the proportion of this AA in breast (P < 0.01) and leg muscles (P < 0.01), along with a rise in the proportion of nonessential AA (NEAA; sum of aspartic, aspartic acid, glutamic, glutamic acid, serine, β-Ala, and proline) (P < 0.01). The levels of BA changed during storage in breast and leg muscles (P < 0.001). The applied diet significantly influenced the formation of putrescine (P = 0.030), phenylethylamine (P = 0.003), agmatine (P = 0.025), and total BA (P < 0.001) in breast muscles. On the 10 d of storage, the breast muscles exhibited the lowest BA index (BAI) in the group, with a diet supplemented with 0.5% garlic extract and 0.5% β-Ala (P < 0.05). The leg muscles showed a similar BA trend as the breast muscles. These supplements may be utilized in production to augment the protein content of chicken muscles and potentially decrease the BAI index during meat storage.

The potential of traditional herbal active ingredients in the treatment of sarcopenia animal models: focus on therapeutic effects and mechanisms

Sarcopenia is a major global public health problem that harms individual physical function. In 2018, the European Working Group on Sarcopenia in the Elderly 2 classified sarcopenia into primary and secondary sarcopenia. However, information on the pathogenesis and effective treatment of primary and secondary sarcopenia is limited. Traditional herbal active ingredients have biological activities that promote skeletal muscle health, showing potential preventive and therapeutic effects on sarcopenia. Therefore, this narrative review aims to provide a comprehensive overview of global traditional herbal active ingredients' beneficial therapeutic effects and molecular mechanisms on sarcopenia-related animal models. For this purpose, we conducted a literature search in three databases, PubMed, Web of Science, and Embase, consistent with the review objectives. After the screening, 12 animal studies met the review themes. The review results showed that the pathological mechanisms in sarcopenia-related animal models include imbalanced protein metabolism, oxidative stress, inflammation, apoptosis, insulin resistance, endoplasmic reticulum stress, impaired mitochondrial biogenesis, and autophagy-lysosome system aggravation. Eleven traditional herbal active ingredients exerted positive anti-sarcopenic effects by ameliorating these pathological mechanisms. This narrative review will provide meaningful insight into future studies regarding traditional herbal active ingredients for treating sarcopenia.

Saponin extract from Achyranthes bidentata Blume alleviates disuse-induced muscle atrophy through PI3K/Akt signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The roots of Achyranthes bidentata Blume are one of the regularly used herbal drugs in Chinese medicine, and has been applied for strengthening the muscle and bone for a long time. However, its effect on muscle remains unclear.

AIM OF THE STUDY

This paper aims to explore the anti-muscle atrophy effect of A. bidentata, and to clarify the possible signaling pathways involved.

MATERIALS AND METHODS

The saponin extract of the roots of A. bidentata (ABSE) was prepared and analyzed, and its activity on myoblast differentiation was assayed with C2C12 cell culture. ABSE was then orally administered at dosage of 35, 70 and 140 mg/kg/day to disuse-induced muscle atrophy mice. The studies on mice body weight and muscle quality were conducted, and Western blot was used for exploring the possible signaling pathways involved in the muscle protective action aided with transcriptome analysis.

RESULTS

The total saponin content of ABSE was 59.1%. ABSE promoted the C2C12 cells differentiation to myotube in C2C12 differentiation assay. Further study with disuse-induced muscle atrophy mice model demonstrated that ABSE significantly increased muscle fiber diameter as well as the proportion of slow muscle fibers. Possible mechanism study aided with transcriptome analysis revealed that ABSE alleviated muscle atrophy at least through activation of PI3K/Akt pathway in vivo & vitro.

CONCLUSIONS

The saponin extract of the root of A. bidentata (ABSE) has a protective effect on muscle atrophy, and showed a considerable potential in prevention and treatment of muscle atrophy.

Pathogenesis, Intervention, and Current Status of Drug Development for Sarcopenia: A Review

Sarcopenia refers to the loss of muscle strength and mass in older individuals and is a major determinant of fall risk and impaired ability to perform activities of daily living, often leading to disability, loss of independence, and death. Owing to its impact on morbidity, mortality, and healthcare expenditure, sarcopenia in the elderly has become a major focus of research and public policy debates worldwide. Despite its clinical importance, sarcopenia remains under-recognized and poorly managed in routine clinical practice, partly owing to the lack of available diagnostic testing and uniform diagnostic criteria. Since the World Health Organization and the United States assigned a disease code for sarcopenia in 2016, countries worldwide have assigned their own disease codes for sarcopenia. However, there are currently no approved pharmacological agents for the treatment of sarcopenia; therefore, interventions for sarcopenia primarily focus on physical therapy for muscle strengthening and gait training as well as adequate protein intake. In this review, we aimed to examine the latest information on the epidemiology, molecular mechanisms, interventions, and possible treatments with new drugs for sarcopenia.

The beneficial therapeutic effects of plant-derived natural products for the treatment of sarcopenia

Sarcopenia is an age-related muscle disorder typically associated with a poor quality of life. Its definition has evolved over time, and several underlying causes of sarcopenia in the elderly have been proposed. However, the exact mechanisms involved in sarcopenia, as well as effective treatments for this condition, are not fully understood. The purpose of this article was to conduct a comprehensive review of previous evidence regarding the definition, diagnosis, risk factors, and efficacy of plant-derived natural products for sarcopenia. The methodological approach for the current narrative review was performed using PubMed, Scopus, and Web of Science databases, as well as Google Scholar (up to March 2021) in order to satisfy our objectives. The substantial beneficial effects along with the safety of some plant-derived natural products including curcumin, resveratrol, catechin, soy protein, and ginseng on sarcopenia are reported in this review. Based on clinical studies, nutraceuticals and functional foods may have beneficial effects on physical performance, including handgrip and knee-extension strength, weight-lifting capacity, time or distance travelled before feeling fatigued, mitochondrial function, muscle fatigue, mean muscle fibre area, and total number of myonuclei. In preclinical studies, supplementation with herbs and natural bioactive compounds resulted in beneficial effects including increased plantaris mass, skeletal muscle mass and strength production, increased expression of anabolic factors myogenin, Myf5 and MyoD, enhanced mitochondrial capacity, and inhibition of muscle atrophy and sarcopenia. We found that several risk factors such as nutritional status, physical inactivity, inflammation, oxidative stress, endocrine system dysfunction, insulin resistance, history of chronic disease, mental health, and genetic factors are linked or associated with sarcopenia. The substantial beneficial effects of some nutraceuticals and functional foods on sarcopenia, including curcumin, resveratrol, catechin, soy protein, and ginseng, without any significant side effects, are reported in this review. Plant-derived natural products might have a beneficial effect on various components of sarcopenia. Nevertheless, due to limited human trials, the clinical benefits of plant-derived natural products remain inconclusive. It is suggested that comprehensive longitudinal clinical studies to better understand risk factors over time, as well as identifying a treatment strategy for sarcopenia that is based on its pathophysiology, be undertaken in future investigations.

Beneficial Effect of H2S-Releasing Molecules in an In Vitro Model of Sarcopenia: Relevance of Glucoraphanin

Sarcopenia is a gradual and generalized skeletal muscle (SKM) syndrome, characterized by the impairment of muscle components and functionality. Hydrogen sulfide (H₂S), endogenously formed within the body from the activity of cystathionine-γ-lyase (CSE), cystathionine- β-synthase (CBS), and mercaptopyruvate sulfurtransferase, is involved in SKM function. Here, in an in vitro model of sarcopenia based on damage induced by dexamethasone (DEX, 1 μM, 48 h treatment) in C2C12-derived myotubes, we investigated the protective potential of exogenous and endogenous sources of H₂S, i.e., glucoraphanin (30 μM), L-cysteine (150 μM), and 3-mercaptopyruvate (150 μM). DEX impaired the H₂S signalling in terms of a reduction in CBS and CSE expression and H₂S biosynthesis. Glucoraphanin and 3-mercaptopyruvate but not L-cysteine prevented the apoptotic process induced by DEX. In parallel, the H₂S-releasing molecules reduced the oxidative unbalance evoked by DEX, reducing catalase activity, O₂⁻ levels, and protein carbonylation. Glucoraphanin, 3-mercaptopyruvate, and L-cysteine avoided the changes in myotubes morphology and morphometrics after DEX treatment. In conclusion, in an in vitro model of sarcopenia, an impairment in CBS/CSE/H₂S signalling occurs, whereas glucoraphanin, a natural H₂S-releasing molecule, appears more effective for preventing the SKM damage. Therefore, glucoraphanin supplementation could be an innovative therapeutic approach in the management of sarcopenia.

A Review of Sarcopenia Pathophysiology, Diagnosis, Treatment and Future Direction

Sarcopenia is a progressive and generalized loss of skeletal muscle mass and function. The prevalence of sarcopenia was reported to be up to 29% in older persons in the community healthcare setting. Sarcopenia diagnosis is confirmed by the presence of low muscle mass plus low muscle strength or low physical performance. Sarcopenia management options include non-pharmacological and pharmacological approaches. Non-pharmacological approaches include resistance exercise and adequate nutrition. Of the two, resistance exercise is the standard non-pharmacological treatment approach for sarcopenia with significant positive evidence. Some dietary approaches such as adequate intake of protein, vitamin D, antioxidant nutrients, and long-chain polyunsaturated fatty acid have been shown to have positive effects against sarcopenia. Currently, no specific drugs have been approved by the Food and Drug Administration for the treatment of sarcopenia. However, several agents, including growth hormone, anabolic or androgenic steroids, selective androgenic receptor modulators, protein anabolic agents, appetite stimulants, myostatin inhibitors, activating II receptor drugs, β-receptor blockers, angiotensin-converting enzyme inhibitors, and troponin activators, are recommended and have been shown to have variable efficacy. Future research should focus on sarcopenia biological pathway and improved diagnostic approaches such as biomarkers for early detection, development of consistently pre-eminent treatment methods for severe sarcopenia patients, and establishing sensitive measures for predicting sarcopenia treatment response.

Ginger for Healthy Ageing: A Systematic Review on Current Evidence of Its Antioxidant, Anti-Inflammatory, and Anticancer Properties

The world's population is ageing at an accelerated pace. Ageing is a natural, physiological but highly complex and multifactorial process that all species in the Tree of Life experience over time. Physical and mental disabilities, and age-related diseases, would increase along with the increasing life expectancy. Ginger (Zingiber officinale) is a plant that belongs to the Zingiberaceae family, native to Southeast Asia. For hundreds of years, ginger has been consumed in various ways by the natives of Asian countries, both as culinary and medicinal herb for the treatment of many diseases. Mounting evidence suggests that ginger can promote healthy ageing, reduce morbidity, and prolong healthy lifespan. Ginger, a well-known natural product, has been demonstrated to possess antioxidant, anti-inflammatory, anticancer, and antimicrobial properties, as well as an outstanding antiviral activity due to a high concentration of antiviral compounds. In this review, the current evidence on the potential role of ginger and its active compounds in the prevention of ageing is discussed.

Panax ginseng and aging related disorders: A systematic review

The aging process predisposes numerous homeostatic disorders, metabolic disorders, cardiovascular diseases, neurodegenerative diseases, and cancer. Changes in diet and lifestyle and therapeutic adjuvants are essential to minimize the effects of comorbidities associated with aging. Natural products such as Panax ginseng have been used to treat and prevent diseases related to aging. This review aims to investigate the effects of Panax ginseng in various conditions associated with aging, such as inflammation, oxidative stress, mitochondrial dysfunction, apoptosis, neurodegenerative and metabolic disorders, cardiovascular diseases, and cancer. The ginsenosides, chemical constituents found in Panax ginseng, can inhibit the effects of inflammatory cytokines, inhibit signaling pathways that induce inflammation, and inhibit cells that participate in inflammatory processes. Besides, ginsenosides are involved in neuroprotective effects on the central nervous system due to anti-apoptotic, antioxidant, and anti-inflammatory effects. The use of ginseng extract showed actions on lipid homeostasis, positively regulating high-density lipoprotein, down-regulating low-density lipoprotein and triglyceride levels, and producing beneficial effects on vascular endothelial function. The use of this plant in cancer resulted in improved quality of life and mood. It decreased symptoms of fatigue, nausea, vomiting, and dyspnea, reducing anxiety. Panax ginseng has been shown to exert potent therapeutic benefits that can act as a complementary treatment in managing patients with chronic diseases related to aging.

Nutrient weight against sarcopenia: regulation of the IGF-1/PI3K/Akt/FOXO pathway in quinoa metabolites

Sarcopenia is characterized by the loss of muscle mass and strength, and one of its major molecular mechanisms is muscle protein turnover. Quinoa, the grain-like food crop, is a health nutrient used to treat diseases that predispose individuals to muscle wasting, including cardiovascular disorders, diabetes mellitus, and cancer. Quinoa secondary metabolites have recently been demonstrated to regulate protein turnover (including protein synthesis and degradation), a main biological process within muscle cells, through diverse signals (such as the p38 MAPK, TNF-α, and IGF-1/PI3K/Akt/FOXO pathways). Here, we describe how quinoa functions in the main pathway of protein synthesis and degradation, screen promising pharmacological components in nutritional applications, and provide guidance for the effects of quinoa products in sarcopenia.

Chronic Systemic Curcumin Administration Antagonizes Murine Sarcopenia and Presarcopenia

Curcumin administration attenuates muscle disuse atrophy, but its effectiveness against aging-induced, selective loss of mass or force (presarcopenia or asthenia/dynopenia), or combined loss (sarcopenia), remains controversial. A new systemic curcumin treatment was developed and tested in 18-month-old C57BL6J and C57BL10ScSn male mice. The effects on survival, liver toxicity, loss of muscle mass and force, and satellite cell responsivity and commitment were evaluated after 6-month treatment. Although only 24-month-old C57BL10ScSn mice displayed age-related muscle impairment, curcumin significantly increased survival of both strains (+20–35%), without signs of liver toxicity. Treatment prevented sarcopenia in soleus and presarcopenia in EDL of C57BL10ScSn mice, whereas it did not affect healthy-aged muscles of C57BL6J. Curcumin-treated old C57BL10ScSn soleus preserved type-1 myofiber size and increased type-2A one, whereas EDL maintained adult values of total myofiber number and fiber-type composition. Mechanistically, curcumin only partially prevented the age-related changes in protein level and subcellular distribution of major costamere components and regulators. Conversely, it affected satellite cells, by maintaining adult levels of myofiber maturation in old regenerating soleus and increasing percentage of isolated, MyoD-positive satellite cells from old hindlimb muscles. Therefore, curcumin treatment successfully prevents presarcopenia and sarcopenia development by improving satellite cell commitment and recruitment.

A novel quercetin/β-cyclodextrin transdermal gel, combined or not with therapeutic ultrasound, reduces oxidative stress after skeletal muscle injury

A gel containing the inclusion complex of quercetin and β-cyclodextrin was developed in order to verify its effects, isolated or using phonophoresis, on oxidative biomarkers after skeletal muscle injury. 30 male rats were divided into one of five groups: Control (CTRL), Muscle Injury (MI), Therapeutic Pulsed Ultrasound (TPU), Therapeutic Pulsed Ultrasound plus Quercetin (TPU plus gel-QUE) or Quercetin gel (QUE). Quercetin gel was complexed with β-Cyclodextrin (β-CD) using chromatography (HPLC). TPU and quercetin application occurred with 2, 12, 24, 48, 72, 96 hours intervals after injury. Gastrocnemius muscle was injured by mechanical trauma. Lipid peroxidation, superoxide dismutase activity, and catalase activity were assessed. The inclusion complex exhibited adequate entrapment efficiency, relative density and pH. The viscosity of the complex showed a non-Newtonian pseudoplastic behavior. Quercetin/β-cyclodextrin gel reduced lipid peroxidation, superoxide dismutase activity and catalase activity compared to muscle injury group. Similarly, phonophoresis and TPU also reduced the levels of these oxidative biomarkers. In conclusion, quercetin/β-cyclodextrin transdermal gel reduces oxidative stress biomarkers after skeletal muscle injury irrespective of using phonophoresis.

Sarcopenia versus cancer cachexia: the muscle wasting continuum in healthy and diseased aging

Muscle wasting is one of the major health problems in older adults and is traditionally associated to sarcopenia. Nonetheless, muscle loss may also occur in older adults in the presence of cancer, and in this case, it is associated to cancer cachexia. The clinical management of these conditions is a challenge due to, at least in part, the difficulties in their differential diagnosis. Thus, efforts have been made to better comprehend the pathogenesis of sarcopenia and cancer cachexia, envisioning the improvement of their clinical discrimination and treatment. To add insights on this topic, this review discusses the current knowledge on key molecular players underlying sarcopenia and cancer cachexia in a comparative perspective. Data retrieved from this analysis highlight that while sarcopenia is characterized by the atrophy of fast-twitch muscle fibers, in cancer cachexia an increase in the proportion of fast-twitch fibers appears to happen. The molecular drivers for these specificmuscle remodeling patterns are still unknown; however, among the predominant contributors to sarcopenia is the age-induced neuromuscular denervation, and in cancer cachexia, the muscle disuse experienced by cancer patients seems to play an important role. Moreover, inflammation appears to be more severe in cancer cachexia. Impairment of nutrition-related mediators may also contribute to sarcopenia and cancer cachexia, being distinctly modulated in each condition.

Herbal medicine for the prevention of sarcopenia: A protocol for systematic review

BACKGROUND

Sarcopenia is a syndrome characterized by a gradual and generalized loss of skeletal muscle mass and strength leading to physical disability, poor quality of life, and possible death. The disease impacts the steadily increasing aging population worldwide. In this systematic review protocol, we aim to investigate the effects and safety of herbal medicines on skeletal muscle health, specifically focusing on possible treatments for preventing sarcopenia.

METHODS

Nine electronic databases will be comprehensively searched from inception to the present date. Clinical studies reporting on the effects and safety of herbal medicines associated with skeletal muscle health and the prevention of sarcopenia will be included. The primary outcome will be determined by five categories: anti-inflammatory and antioxidant efficacy, muscle damage prevention, anti-fatigue effect, muscle-atrophy prevention, and muscle regeneration and differentiation. Two independent researchers will perform the research selection, data extraction, and quality assessment processes. The Cochrane risk-of-bias tool will be used to assess the methodological quality and design of the included studies. We will place no restrictions on publication status or language, and the results of the systematic review will be disseminated electronically and in print by publication in a peer-reviewed journal.

RESULTS

The present study will evaluate the effects and safety of herbal medicines for the prevention of sarcopenia.

CONCLUSION

Our findings will provide guidance on the use of herbal medicines to prevent sarcopenia. This knowledge is valuable for elderly people, clinicians treating patients with sarcopenia, policy makers, and researchers.

REGISTRATION NUMBER

Reviewregistry1113 (URL: https://www.researchregistry.com/browse-the-registry#registryofsystematicreviewsmeta-analyses/registryofsystematicreviewsmeta-analysesdetails/604a1e5ef176d2001b557750/).

Combined Effects of Exercise and Phytoanabolic Extracts in Castrated Male and Female Mice

Dry extracts from the Eurasian plants, Ajuga turkestanica, Eurycoma longifolia, and Urtica dioica have been used as anabolic supplements, despite the limited scientific data on these effects. To assess their actions on early sarcopenia signs, male and female castrated mice were supplemented with lyophilized extracts of the three plants, isolated or in association (named TLU), and submitted to resistance exercise. Ovariectomy (OVX) led to body weight increase and non-high-density cholesterol (HDL) cholesterol elevation, which had been restored by exercise plus U. dioica extract, or by exercise and TLU, respectively. Orchiectomy (ORX) caused skeletal muscle weight loss, accompanied by increased adiposity, being the latter parameter reduced by exercise plus E. longifolia or U. dioica extracts. General physical activity was improved by exercise plus herbal extracts in either OVX or ORX animals. Exercise combined with TLU improved resistance to fatigue in OVX animals, though A. turkestanica enhanced the grip strength in ORX mice. E. longifolia or TLU also reduced the ladder climbing time in ORX mice. Resistance exercise plus herbal extracts partly altered gastrocnemius fiber size frequencies in OVX or ORX mice. We provide novel data that tested ergogenic extracts, when combined with resistance exercise, improved early sarcopenia alterations in castrated male and female mice.

Diospyros kaki extract protects myoblasts from oxidative stress-induced cytotoxicity via secretions derived from intestinal epithelium

Under oxidative stress, reactive oxygen species (ROS) alter signal transduction and induce macromolecular damage in cells. Such oxidative damage can lead to sarcopenia, an age-related syndrome characterized by a progressive loss of mass and strength of skeletal muscles. Because food components do not directly come in contact with muscle cells, we focused on the effects of secretions produced by stimulated intestinal epithelial cells on oxidative stress in myoblast cells. An extract of Diospyros kaki was fractionated using different concentrations of ethanol. Each fraction showed different levels of antioxidant and phenolic compounds. The biological activity was evaluated using a Caco-2 cell coculture system. Secretions from Caco-2 cells exposed to 0.5 mg/mL D. kaki extract attenuated the oxidative stress-induced reduction of C2C12 cell viability, suggesting that the D. kaki extract could stimulate intestinal epithelial cells to produce secretions that reduce oxidative stress in myoblasts in vitro.

Report and Abstracts of the 17th Meeting of IIM, the Interuniversity Institute of Myology:Virtual meeting, October 16-18, 2020

In 2020, due to the COVID-19 pandemic, the annual meeting of the Interuniversity Institute of Myology (IIM), took place on a virtual platform. Attendees were scientists and clinicians, as well as pharmaceutical companies and patient organization representatives from Italy, several European countries, Canada and USA. Four internationally renowned Keynote speakers presented recent advances on muscle stem cells regulation, skeletal muscle regeneration, quantitative biology approaches, and metabolic regulation of muscle homeostasis. Novel, unpublished data by young trainees were presented as oral communications or posters, in five scientific sessions and two poster sessions. On October 15, 2020, selected young trainees participated to the High Training Course on "Advanced Myology", organized together with the University of Perugia, Italy. The course, on a virtual platform, showcased lectures on muscle development and regulation of muscle gene expression by international speakers, and roundtables discussions on "Single cell analysis of skeletal muscle" and "Skeletal muscle stem cell in healthy muscle and disease". The Young IIM Committee, composed by young trainee winners of awards in the past IIM Meeting editions, was directly involved in the selection of keynote speakers, the organization of scientific sessions and roundtables discussions tailored to the interests of their peers. A broad audience of Italian, European and North American participants contributed to the different initiatives. The meeting was characterized by a friendly and inclusive atmosphere, facilitating lively and stimulating discussions on emerging areas of muscle research. The meeting stimulated scientific cross-fertilization fostering novel ideas and scientific collaborations aimed at better understanding muscle normal physiology and the mechanisms underlaying muscle diseases, with the ultimate goal of developing better therapeutic strategies. The meeting was a success, and the number of meeting attendees was the highest of all IIM Meeting editions. Despite the current difficulties imposed by the COVID-19 pandemic, we are confident that the IIM community will continue to grow and deliver significant contributions to the understanding of muscle development and function, the pathogenesis of muscular diseases and the development of novel therapeutic approaches. Here, abstracts of the meeting illustrate the new results on basic, translational, and clinical research, confirming that our field is strong and healthy.

Identification of Withania somnifera-Silybum marianum-Trigonella foenum-graecum Formulation as a Nutritional Supplement to Contrast Muscle Atrophy and Sarcopenia

Background: Muscle atrophy, i.e., the loss of skeletal muscle mass and function, is an unresolved problem associated with aging (sarcopenia) and several pathological conditions. The imbalance between myofibrillary protein breakdown (especially the adult isoforms of myosin heavy chain, MyHC) and synthesis, and the reduction of muscle regenerative potential are main causes of muscle atrophy. Methods: Starting from one-hundred dried hydroalcoholic extracts of medical plants, we identified those able to contrast the reduction of C2C12 myotube diameter in well-characterized in vitro models mimicking muscle atrophy associated to inflammatory states, glucocorticoid treatment or nutrient deprivation. Based on their ability to rescue type II MyHC (MyHC-II) expression in atrophying conditions, six extracts with different phytochemical profiles were selected, mixed in groups of three, and tested on atrophic myotubes. The molecular mechanism underpinning the effects of the most efficacious formulation, and its efficacy on myotubes obtained from muscle biopsies of young and sarcopenic subjects were also investigated. Results: We identified WST (Withania somnifera, Silybum marianum, Trigonella foenum-graecum) formulation as extremely efficacious in protecting C2C12 myotubes against MyHC-II degradation by stimulating Akt (protein kinase B)-dependent protein synthesis and p38 MAPK (p38 mitogen-activated protein kinase)/myogenin-dependent myoblast differentiation. WST sustains trophism in C2C12 and young myotubes, and rescues the size, developmental MyHC expression and myoblast fusion in sarcopenic myotubes. Conclusion: WST strongly counteracts muscle atrophy associated to different conditions in vitro. The future validation in vivo of our results might lead to the use of WST as a food supplement to sustain muscle mass in diffuse atrophying conditions, and to reverse the age-related functional decline of human muscles, thus improving people quality of life and reducing social and health-care costs.

Flavonoids from dark chocolate and (-)-epicatechin ameliorate high-fat diet-induced decreases in mobility and muscle damage in aging mice

Age-related muscle decline, when associated with obesity, leads to adverse outcomes with increased risks for falling, loss of independence, disability and risk of premature mortality. The aim of this study was to assess the potential beneficial effects of flavonoids in improving the age-/high-fat-diet-induced decrease in physical activity/capacity related to the onset of skeletal muscle decline. The effects of the administration of a cocoa beverage enriched with flavanols or pure (-)-epicatechin for 5 wk in a model of physical activity decline induced by the ingestion of a high-fat diet (60% fat) in middle-age mice were evaluated. The results showed that both products, the cocoa beverage enriched with flavanols and pure (-)-epicatechin, improved physical performance evaluated with the hang-wire, inverted-screen, and weight-lifting tests and dynamometry compared with the performance of the controls. The beverage and (-)-epicatechin increased the follistatin/myostatin ratio and increased the expression of myocyte enhancer factor 2A (MEF2A), suggesting an effect on molecular modulators of growth differentiation. Furthermore, the beverage and (-)-epicatechin decreased the expression of O-type fork-head transcription factor (FOXO1A) and muscle ring finger 1 (MURF1) markers of the skeletal muscle ubiquitin-proteasome degradation pathway.

Effects of tannase-converted green tea extract on skeletal muscle development

BACKGROUND

The aim of this study was to investigate the effect of tannase-converted green tea extract with a high (-)-epicatechin (EC), (-)-epigallocatechin (EGC), and gallic acid (GA) content on myotube density and fusion in normal and oxidative stress-induced C2C12 skeletal muscle cells. Although the use of green tea extract is considered beneficial, cellular and molecular mechanisms of action of tannase-converted green tea extracts that are used as potential muscle growth materials have not been thoroughly studied.

METHODS

This study used histological analysis and molecular biology techniques, and compared the results with those for AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribonucleoside (AICAR) and green tea extracts.

RESULTS

The myotube density of normal and oxidative stress-induced C2C12 cells was significantly higher in the tannase-converted green tea extract-treated group than that observed in the other groups (normal cells: P < 0.01; oxidative stress-induced cells: P < 0.05). In addition, tannase-converted green tea extract and green tea extract treatments significantly upregulated the genetic expression of myogenin, Myf5, and MyoD (P < 0.05). The levels of AMP-activated protein kinase-α (AMPKα) and muscle RING-finger protein-1 (MuRF-1) in the tannase-converted green tea extract group were higher than those in the AICAR and green tea extract groups (P < 0.05).

CONCLUSIONS

Taken together, our findings describe that the high levels of EC, EGC, and GA in the tannase-converted green tea extract are attributable to the morphological changes in C2C12 cells and intercellular signaling pathways. Therefore, tannase-converted green tea extract can be used in the treatment of sarcopenia.

Sarcopenia: A Rheumatic Disease?

Sarcopenia refers to the age-related loss of muscle mass, muscle strength, and physical function. With an increase in the number and proportion of elderly in the population, sarcopenia is a growing global health concern due to its impact on morbidity, mortality, and health care expenditure. Despite its clinical importance, sarcopenia remains underrecognized and poorly managed in routine clinical practice. This is, in part, due to a lack of available diagnostic testing and uniform diagnostic criteria. This article provides the general practitioner or rheumatologist an overview of the pathophysiology, diagnosis, and management of this complex and critical entity.

Pathogenesis and Management of Sarcopenia

Sarcopenia represents a loss of muscle strength and mass in older individuals. Sarcopenia in the elderly has now become a major focus of research and public policy debate due to its impact on morbidity, mortality, and health care expenditure. Despite its clinical importance, sarcopenia remains under-recognized and poorly managed in routine clinical practice. This is, in part, due to a lack of available diagnostic testing and uniform diagnostic criteria. The management of sarcopenia is primarily focused on physical therapy for muscle strengthening and gait training. There are no pharmacologic agents for the treatment of sarcopenia.