Curcumin Attenuates Sarcopenia in Chronic Forced Exercise Executed Aged Mice by Regulating Muscle Degradation and Protein Synthesis with Antioxidant and Anti-inflammatory Effects

Wheat seedlings extract ameliorates sarcopenia in aged mice by regulating protein synthesis and degradation with anti-inflammatory and mitochondrial biogenesis effects

BACKGROUND

Chronic inflammation, which becomes more prevalent during aging, contributes to sarcopenia by reducing muscle mass and strength.

PURPOSE

Wheat seedlings extract (WSE) is known for its various physiological activities, including anti-inflammation and antioxidant effects. However, its efficacy against sarcopenia is not well documented.

STUDY DESIGN

8-week-old and 50-week-old C57BL/6 J mice were used as young control (YC group) and aged controls (AC group), respectively. Then, aged mice were randomly divided into 5 groups (WSE100mg/kg, WSE200mg/kg, WSE400mg/kg, and schizandrin as a positive control) and fed each experimental diet for 10 weeks.

METHOD

We investigated the effects of WSE on muscle quality and protein homeostasis pathways based on improvements in mitochondrial function and chronic inflammation. We then used TNFα-treated C2C12 to investigate the effects of isoorientin (ISO) and isoschaftoside (ISS), the active substances of WSE, on the myogenic pathway.

RESULTS

We administered WSE to aging mice and observed an increase in muscle mass, thickness, protein content, and strength in mice treated with WSE at a dose of 200 mg/kg or 400 mg/kg. Furthermore, the administration of WSE led to a reduction in inflammatory factors (TNFα, IL-1, and IL-6) and an increase in mitochondrial biogenesis (p-AMPK/SIRT3/PGC1α) in muscle. This effect was also observed in TNFα-induced muscle atrophy in C2C12 cells, and we additionally identified the upregulation of myogenic regulatory factors, including Myf5, Myf6, MyoD, and myogenin, by WSE, ISO, and ISS.

CONCLUSION

These findings suggest that WSE could function as a dietary anti-inflammatory factor and mitochondrial activator, potentially exerting modulatory effects on the metabolism and mechanical properties of skeletal muscles in the aging population. Furthermore, Our results demonstrate the potential value of ISO and ISS as functional food ingredients for preventing muscle atrophy.

d-Pinitol Improves Diabetic Sarcopenia by Regulation of the Gut Microbiome, Metabolome, and Proteome in STZ-Induced SAMP8 Mice

d-Pinitol (DP) is primarily found in Vigna sinensis, which has been shown to have hypoglycemic and protective effects on target organs. However, the mechanism of DP in treating diabetic sarcopenia (DS) is still unclear. To explore the underlying mechanism of DS and the protective targets of DP by high-throughput analysis of 16S rRNA gene, metabolome, and the proteome. Streptozotocin-induced SAMP8 mice were intragastrically administrated DP (150 mg/kg) for 8 weeks. Fecal 16S rRNA gene sequencing and gastrocnemius muscle metabolomic and proteomic analyses were completed to investigate the gut-muscle axis interactions. DP significantly alleviated the muscle atrophy in diabetic mice. Dysfunction of the gut microbiota was observed in the DS mice. DP significantly reduced the Parabacteroides, Akkermansia, and Enterobacteriaceae, while it increased Lachnospiraceae_NK4A136. Metabolome and proteome revealed that 261 metabolites and 626 proteins were significantly changed in the gastrocnemius muscle of diabetic mice. Among these, DP treatment restored 44 metabolites and 17 proteins to normal levels. Functional signaling pathways of DP-treated diabetic mice included nucleotide metabolism, β-alanine, histidine metabolism, ABC transporters, and the calcium signaling pathway. We systematically explored the molecular mechanism of DS and the protective effect of DP, providing new insights that may advance the treatment of sarcopenia.

Nutritional approaches targeting mitochondria for the prevention of sarcopenia

A decline in function and loss of mass, a condition known as sarcopenia, is observed in the skeletal muscles with aging. Sarcopenia has a negative effect on the quality of life of elderly. Individuals with sarcopenia are at particular risk for adverse outcomes, such as reduced mobility, fall-related injuries, and type 2 diabetes mellitus. Although the pathogenesis of sarcopenia is multifaceted, mitochondrial dysfunction is regarded as a major contributor for muscle aging. Hence, the development of preventive and therapeutic strategies to improve mitochondrial function during aging is imperative for sarcopenia treatment. However, effective and specific drugs that can be used for the treatment are not yet approved. Instead studies on the relationship between food intake and muscle aging have suggested that nutritional intake or dietary control could be an alternative approach for the amelioration of muscle aging. This narrative review approaches various nutritional components and diets as a treatment for sarcopenia by modulating mitochondrial homeostasis and improving mitochondria. Age-related changes in mitochondrial function and the molecular mechanisms that help improve mitochondrial homeostasis are discussed, and the nutritional components and diet that modulate these molecular mechanisms are addressed.

Curcumin regulates autophagy through SIRT3-SOD2-ROS signaling pathway to improve quadriceps femoris muscle atrophy in KOA rat model

Knee osteoarthritis (KOA) usually leads to quadriceps femoris atrophy, which in turn can further aggravate the progression of KOA. Curcumin (CUR) has anti-inflammatory and antioxidant effects and has been shown to be a protective agent for skeletal muscle. CUR has been shown to have a protective effect on skeletal muscle. However, there are no studies related to whether CUR improves KOA-induced quadriceps femoris muscle atrophy. We established a model of KOA in rats. Rats in the experimental group were fed CUR for 5 weeks. Changes in autophagy levels, reactive oxygen species (ROS) levels, and changes in the expression of the Sirutin3 (SIRT3)-superoxide dismutase 2 (SOD2) pathway were detected in the quadriceps femoris muscle of rats. KOA led to quadriceps femoris muscle atrophy, in which autophagy was induced and ROS levels were increased. CUR increased SIRT3 expression, decreased SOD2 acetylation and ROS levels, inhibited the over-activation of autophagy, thereby alleviating quadriceps femoris muscle atrophy and improving KOA. CUR has a protective effect against quadriceps femoris muscle atrophy, and KOA is alleviated after improvement of quadriceps femoris muscle atrophy, with the possible mechanism being the reduction of ROS-induced autophagy via the SIRT3-SOD2 pathway.

Chitosan nanoparticles encapsulating curcumin counteract salt-mediated ionic toxicity in wheat seedlings: an ecofriendly and sustainable approach

Over-accumulating salts in soil are hazardous materials that interfere with the biochemical pathways in growing plants drastically affecting their physiological attributes, growth, and productivity. Soil salinization poses severe threats to highly-demanded and important crops directly challenging food security and sustainable productivity. Recently, there has been a great demand to exploit natural sources for the development of nontoxic nanoformulations of growth enhancers and stress emulators. The chitosan (CS) has growth-stimulating properties and widespread use as nanocarriers, while curcumin (CUR) has a well-established high ROS scavenging potential. Herein, we use CS and CUR for the preparation of CSNPs encapsulating CUR as an ecofriendly nanopriming agent. The hydroprimed, nanoprimed (0.02 and 0.04%), and unprimed (control) wheat seeds were germinated under salt stress (150 mM NaCl) and normal conditions. The seedlings established from the aforementioned seeds were employed for germination studies and biochemical analyses. Priming imprints mitigated the ionic toxicity by upregulating the machinery of antioxidants (CAT, POD, APX, and SOD), photosynthetic pigments (Chl a, Chl b, total Chl, and lycopene), tannins, flavonoids, and protein contents in wheat seedlings under salt stress. It controlled ROS production and avoided structural injuries, thus reducing MDA contents and regulating osmoregulation. The nanopriming-induced readjustments in biochemical attributes counteracted the ionic toxicity and positively influenced the growth parameters including final germination, vigor, and germination index. It also reduced the mean germination time, significantly validating the growth-stimulating and stress-emulating role of the prepared nanosystem. Hence, the nanopriming conferred tolerance against salt stress during germination and seedling development, ensuring sustainable growth.

Curcumin as a Therapeutic Agent for Sarcopenia

Sarcopenia is the progressive loss of muscle mass, strength, and functions as we age. The pathogenesis of sarcopenia is underlined by oxidative stress and inflammation. As such, it is reasonable to suggest that a natural compound with both antioxidant and anti-inflammatory activities could prevent sarcopenia. Curcumin, a natural compound derived from turmeric with both properties, could benefit muscle health. This review aims to summarise the therapeutic effects of curcumin on cellular, animal, and human studies. The available evidence found in the literature showed that curcumin prevents muscle degeneration by upregulating the expression of genes related to protein synthesis and suppressing genes related to muscle degradation. It also protects muscle health by maintaining satellite cell number and function, protecting the mitochondrial function of muscle cells, and suppressing inflammation and oxidative stress. However, it is noted that most studies are preclinical. Evidence from randomised control trials in humans is lacking. In conclusion, curcumin has the potential to be utilised to manage muscle wasting and injury, pending more evidence from carefully planned human clinical trials.

Accounting Gut Microbiota as the Mediator of Beneficial Effects of Dietary (Poly)phenols on Skeletal Muscle in Aging

Sarcopenia, the age-related loss of muscle mass and function increasing the risk of disability and adverse outcomes in older people, is substantially influenced by dietary habits. Several studies from animal models of aging and muscle wasting indicate that the intake of specific polyphenol compounds can be associated with myoprotective effects, and improvements in muscle strength and performance. Such findings have also been confirmed in a smaller number of human studies. However, in the gut lumen, dietary polyphenols undergo extensive biotransformation by gut microbiota into a wide range of bioactive compounds, which substantially contribute to bioactivity on skeletal muscle. Thus, the beneficial effects of polyphenols may consistently vary across individuals, depending on the composition and metabolic functionality of gut bacterial communities. The understanding of such variability has recently been improved. For example, resveratrol and urolithin interaction with the microbiota can produce different biological effects according to the microbiota metabotype. In older individuals, the gut microbiota is frequently characterized by dysbiosis, overrepresentation of opportunistic pathogens, and increased inter-individual variability, which may contribute to increasing the variability of biological actions of phenolic compounds at the skeletal muscle level. These interactions should be taken into great consideration for designing effective nutritional strategies to counteract sarcopenia.

Physiologically-obtainable polyphenol exposures modulate reactive oxygen and nitrogen species signaling in the C2C12 model of skeletal muscle ageing

Age-related frailty is a significant health and social care burden, with limited treatment options. There is a lack of suitable cell culture model for screening large numbers of test compounds to identify those which promote healthy skeletal muscle function. This paper describes the characterization of reactive oxygen and nitrogen species (RONS) signalling changes in young and aged myoblasts and myotubes using C₂C₁₂ cells, and the application of aged cultures to assess the effect of dietary polyphenols on RONS signalling. Aged myoblasts and myotubes showed significantly increased reactive oxygen species (p < 0.01 and p < 0.001 respectively), nitric oxide (p < 0.05 for myoblasts and myotubes), and lipid peroxidation (p < 0.05 for myoblasts and myotubes). Nine polyphenols were assessed in aged myoblasts and myotubes using concentrations and incubation times consistent with known pharmacokinetic parameters for these compounds. Although several polyphenols were seen to reduce single markers of RONS signalling, only kaempferol and resveratrol significantly reduced multiple markers in both cell models. Modulation of enzymatic antioxidant activities was assessed as a possible mechanism of action, although superoxide dismutase and catalase activities were significantly reduced in aged (versus young) myotubes (p < 0.01 and p < 0.05 respectively), no effect of polyphenol treatment on these enzyme activities were observed. Overall, this research has shown the utility of the C₂C₁₂ model (myoblasts and myotubes) for screening compounds in aged muscle, and that resveratrol and kaempferol (using pharmacokinetically-informed exposures) can modulate RONS signalling in skeletal muscle cells after an acute exposure.

Deep eutectic solvents: Recent advances in fabrication approaches and pharmaceutical applications

Deep eutectic solvents (DESs) have received increasing attention in the past decade owing to their distinguished properties including biocompatibility, tunability, thermal and chemical stability. Particularly, DESs have joined forces in pharmaceutical industry, not only to efficiently separate actives from natural products, but also to dramatically increase solubility and permeability of drugs, both are critical for the drug absorption and efficacy. As a result, lately DESs have been extensively and practically adopted as versatile drug delivery systems for different routes such as nasal, transdermal and oral administration with enhanced bioavailability. This review summarizes the emerging progress of DESs by introducing applied fabrication approaches with advantages and limitations thereof, and by highlighting the pharmaceutical applications of DESs.