An Integrated Approach to Skeletal Muscle Health in Aging.

A decline in muscle mass and function represents one of the most problematic changes associated with aging, and has dramatic effects on autonomy and quality of life. Several factors contribute to the inexorable process of sarcopenia, such as mitochondrial and autophagy dysfunction, and the lack of regeneration capacity of satellite cells. The physiologic decline in muscle mass and in motoneuron functionality associated with aging is exacerbated by the sedentary lifestyle that accompanies elderly people. Regular physical activity is beneficial to most people, but the elderly need well-designed and carefully administered training programs that improve muscle mass and, consequently, both functional ability and quality of life. Aging also causes alteration in the gut microbiota composition associated with sarcopenia, and some advances in research have elucidated that interventions via the gut microbiota-muscle axis have the potential to ameliorate the sarcopenic phenotype. Several mechanisms are involved in vitamin D muscle atrophy protection, as demonstrated by the decreased muscular function related to vitamin D deficiency. Malnutrition, chronic inflammation, vitamin deficiencies, and an imbalance in the muscle-gut axis are just a few of the factors that can lead to sarcopenia. Supplementing the diet with antioxidants, polyunsaturated fatty acids, vitamins, probiotics, prebiotics, proteins, kefir, and short-chain fatty acids could be potential nutritional therapies against sarcopenia. Finally, a personalized integrated strategy to counteract sarcopenia and maintain the health of skeletal muscles is suggested in this review.

Effects of a commercially available branched-chain amino acid-alanine-carbohydrate-based sports supplement on perceived exertion and performance in high intensity endurance cycling tests.

BACKGROUND: Sports nutritional supplements containing branched-chain amino acids (BCAA) have been widely reported to improve psychological and biological aspects connected to central fatigue and performance in endurance exercise, although the topic is still open to debate. The aim of the present study was to determine whether the intake of a commercially available BCAA-based supplement, taken according to the manufacturer's recommendations, could affect the rating of perceived exertion (RPE) and performance indexes at the beginning (1d) and end of a 9-week (9w) scheduled high intensity interval training program, with an experimental approach integrating the determination of psychometric, performance, metabolic and blood biochemical parameters. METHODS: This was a randomized double-blind placebo-controlled study. Thirty-two untrained, healthy young adults (20 males and 12 female) were enrolled. A high-intensity endurance cycling (HIEC) test was used to induce fatigue in the participants: HIEC consisted in ten 90 s sprints interspersed by ten 3 min recovery phases and followed by a final step time to exhaustion was used. In parallel with RPE, haematological values (creatine kinase, alanine, BCAA, tryptophan, ammonia and glucose levels), and performance indexes (maximal oxygen consumption - VO2max, power associated with lactate thresholds - WLT1, WLT2 and time to exhaustion - TTE) were assessed. All subject took the supplement (13.2 g of carbohydrates; 3.2 g of BCAA and 1.6 g of L-alanine per dose) or placebo before each test and training session. Dietary habits and training load were monitored during the entire training period. RESULTS: The administration of the supplement (SU) at 1d reduced RPE by 9% during the recovery phase, as compared to the placebo (PL); at 9w the RPE scores were reduced by 13 and 21% during the sprint and recovery phase, respectively; at 9w, prolonged supplement intake also improved TTE and TRIMP. SU intake invariably promoted a rapid increase (within 1 h) of BCAA serum blood levels and prevented the post-HIEC tryptophan: BCAA ratio increase found in the PL group, at both 1d and 9w. There was no difference in dietary habits between groups and those habits did not change over time; no difference in glycemia was found between SU and PL. VO2max, WLT1 and WLT2 values improved over time, but were unaffected by supplement intake. CONCLUSIONS: On the whole, these results suggest that i) the intake of the BCAA-based commercially available supplement used in this study reduces RPE as a likely consequence of an improvement in the serum tryptophan: BCAA ratio; ii) over time, reduced RPE allows subjects to sustain higher workloads, leading to increased TRIMP and TTE.

Mutual Interactions among Exercise, Sport Supplements and Microbiota.

The adult gut microbiota contains trillions of microorganisms of thousands of different species. Only one third of gut microbiota are common to most people; the rest are specific and contribute to enhancing genetic variation. Gut microorganisms significantly affect host nutrition, metabolic function, immune system, and redox levels, and may be modulated by several environmental conditions, including physical activity and exercise. Microbiota also act like an endocrine organ and is sensitive to the homeostatic and physiological changes associated with training; in turn, exercise has been demonstrated to increase microbiota diversity, consequently improving the metabolic profile and immunological responses. On the other side, adaptation to exercise might be influenced by the individual gut microbiota that regulates the energetic balance and participates to the control of inflammatory, redox, and hydration status. Intense endurance exercise causes physiological and biochemical demands, and requires adequate measures to counteract oxidative stress, intestinal permeability, electrolyte imbalance, glycogen depletion, frequent upper respiratory tract infections, systemic inflammation and immune responses. Microbiota could be an important tool to improve overall general health, performance, and energy availability while controlling inflammation and redox levels in endurance athletes. The relationship among gut microbiota, general health, training adaptation and performance, along with a focus on sport supplements which are known to exert some influence on the microbiota, will be discussed.

Phytochemical composition, antioxidant and antiproliferative activities and effects on nuclear DNA of ethanolic extract from an Italian mycelial isolate of Ganoderma lucidum.

ETHNOPHARMACOLOGICAL RELEVANCE: Ganoderma lucidum (Curtis) P. Karst. (also known as Linghzhi and Reishi) is the most appreciated and revered medicinal mushroom across many Asian countries, but its properties have also attracted interest in Western countries. Indeed, in the West, it is now commercially available as a dietary supplement in preparations mainly made from spores, fruiting bodies and mycelia. It is employed in both nutraceutical and pharmacological formulations either for its immuno-modulating anti-inflammatory properties or as an effective adjuvant therapy in the treatment of several chronic diseases as well as in cancer treatment. AIM OF THE STUDY: The aim of this investigation was to show the phytochemical composition and antioxidant and antiproliferative activities of an ethanolic extract from an Italian mycelial isolate of Ganoderma lucidum and to assess its effects on nuclear DNA. MATERIALS AND METHODS: LC/ESI-MS and tandem mass spectrometry MSMS were used to obtain structural identification of ethanolic G. lucidum extract constituents. Antioxidant activities were determined by the DPPH method, chelating effect on Fe2+ and lipoxygenase inhibition while cytotoxic activities using the MTT assay. Effects on nuclear DNA were evaluated using the DNA nicking assay in a cell-free system and the fast halo assay performed on oxidatively injured human U937 cells; apoptosis induction was investigated using the non-denaturing fast halo assay and DNA laddering detection. RESULTS: This extract was rich in several bioactive compounds, mainly phenolic and triterpenic acids. It showed antioxidant activity and protective effects in oxidatively injured DNA in cell-free analyses and antiproliferative, genotoxic, and proapoptotic effects in the cell model. CONCLUSIONS: Italian G. lucidum mycelium isolate appears to be a source of various natural compounds that may have applications as chemopreventive agents or functional foods.

Melatonin protects hippocampal HT22 cells from the effects of serum deprivation specifically targeting mitochondria.

Neurons contain a high number of mitochondria, these neuronal cells produce elevated levels of oxidative stress and live for a long time without proliferation; therefore, mitochondrial homeostasis is crucial to their health. Investigations have recently focused on mitochondrial dynamics revealing the ability of these organelles to change their distribution and morphology. It is known that mitochondrial fission is necessary for the transmission of mitochondria to daughter cells during mitosis and mitochondrial fragmentation has been used as an indicator of cell death and mitochondrial dysfunction. Oxidative stress is a trigger able to induce changes in the mitochondrial network. The aim of the present study was to determine the effects of melatonin on the mitochondrial network in HT22 serum-deprived cells. Our results showed that serum deprivation increased reactive oxygen species (ROS) content, promoted the activation of plasma membrane voltage-dependent anion channels (VDACs) and affected the expression of pDRP1 and DRP1 fission proteins. Moreover, parallel increases in apoptotic and autophagic features were found. Damaged and dysfunctional mitochondria are deleterious to the cell; hence, the degradation of such mitochondria through mitophagy is crucial to cell survival. Our results suggest that melatonin supplementation reduces cell death and restores mitochondrial function through the regulation of autophagy.

Muscle and Bone Health in Postmenopausal Women: Role of Protein and Vitamin D Supplementation Combined with Exercise Training.

Menopause is an age-dependent physiological condition associated with a natural decline in oestrogen levels, which causes a progressive decrease of muscle mass and strength and bone density. Sarcopenia and osteoporosis often coexist in elderly people, with a prevalence of the latter in elderly women. The profound interaction between muscle and bone induces a negative resonance between the two tissues affected by these disorders worsening the quality of life in the postmenopausal period. It has been estimated that at least 1 in 3 women over age 50 will experience osteoporotic fractures, often requiring hospitalisation and long-term care, causing a large financial burden to health insurance systems. Hormonal replacement therapy is effective in osteoporosis prevention, but concerns have been raised with regard to its safety. On the whole, the increase in life expectancy for postmenopausal women along with the need to improve their quality of life makes it necessary to develop specific and safe therapeutic strategies, alternative to hormonal replacement therapy, targeting both sarcopenia and osteoporosis progression. This review will examine the rationale and the effects of dietary protein, vitamin D and calcium supplementation combined with a specifically-designed exercise training prescription as a strategy to counteract these postmenopausal-associated disorders.

Protective Effect of Juglans regia L. Walnut Extract Against Oxidative DNA Damage.

Walnuts (Juglans regia L.) are relevant components of the Mediterranean diet providing important macronutrients, micronutrients and other bioactive constituents including unsaturated fatty acids, proteins, fiber, vitamins, minerals, phytosterols and polyphenols. Although the walnut beneficial effects in human health are widely recognized by a lot of epidemiologic studies very little is known regarding its effect on damaged DNA. The aim of the present study was to investigate the effect of Juglans regia L. ethanolic extract from kernel on the induction of DNA strand breaks by thiol/Fe3+/O2 mixed function oxidase, tert-butyl hydroperoxide or UVC radiations in acellular and cellular models. Plasmid DNA cleavage and fast Halo assay were used to monitor oxidative damage to DNA. Both approaches showed protection of oxidatively injured DNA. These results agree with a lot of scientific proofs which recommend walnut as dietary adjunct in health promotion and prevention as well as in treatment of lifestyle-related oxidative diseases.

Protective Role of Italian Juglans regia L. nut Ethanolic Extract in Human Keratinocytes under Oxidative and Inflammatory Stress.

OBJECTIVE: In this research, fatty acid profile and polyphenolic content of an ethanolic extract of walnut from Juglans regia L. collected in Central Italy, were characterized. The potential antioxidant and anti-inflammatory effects of the extract were investigated in the human keratinocytes cell line. METHODS: Fatty acid profile was determined by gas chromatography/mass spectrometry analysis, total phenolic content by Folin-Ciocalteu method and aluminum chloride colorimetric method was used for determination of total flavonoids. Kertatinocytes were exposed to t-butyl hydroperoxide or Tumor Necrosis Factor alfa in the absence or presence of extract. Reduced glutathione was determined by Sedlak method; lipid peroxidation was assessed by measuring thiobarbituric acid reactive substances. t-butyl hydroperoxide and Tumor Necrosis Factor alfa-induced intracellular reactive oxygen species were monitored by fluorescent probes. The expression of some genes related to the inflammatory process (IL-6, IL-8, ikB, and ICAM) were analysed by Real-time PCR. RESULTS: JRE contains a favourable fatty acid profile with low saturated fats (19%) and high-unsaturated fats (81%) with a prevalence of the omega-6 linoleic acid (48%). Also a significant amount of polyphenols was found (5,0052 mg gallic acid equivalent/gdw). Antioxidant and anti-inflammatory properties of JRE were observed on analysed cellular model. JRE antioxidants counteracted ROS production, GSH depletion and lipid peroxidation as well downregulated the expression of some genes related to the inflammatory process. Moreover, polyunsaturated fatty acids exhibited anti-inflammatory properties. CONCLUSION: The obtained results uphold walnut as dietary adjunct in health promotion and drive towards its development in drug therapy against chronic inflammatory disorders, including inflammatory skin diseases.

Creatine supplementation prevents the inhibition of myogenic differentiation in oxidatively injured C2C12 murine myoblasts.

Creatine (Cr), one of the most popular nutritional supplements among athletes, has been recently shown to prevent the cytotoxicity caused by different oxidative stressors in various mammalian cell lines, including C2C12 myoblasts, via a direct antioxidant activity. Here, the effect of Cr on the differentiating capacity of C2C12 cells exposed to H(2)O(2) has been investigated. Differentiation into myotubes was monitored using morphological, ultrastructural, and molecular techniques. Treatment with H(2)O(2) (1 h) not only caused a significant (30%) loss of cell viability, but also abrogated the myogenic ability of surviving C2C12. Cr-supplementation (24 h prior to H(2)O(2) treatment) was found to prevent these effects. Interestingly, H(2)O(2)-challenged cells preconditioned with the established antioxidants trolox or N-acetyl-cysteine, although cytoprotected, did not display the same differentiating ability characterizing oxidatively-injured, Cr-supplemented cells. Besides acting as an antioxidant, Cr increased the level of muscle regulatory factors and IGF1 (an effect partly refractory to oxidative stress), the cellular availability of phosphocreatine and seemed to exert some mitochondrially-targeted protective activity. It is concluded that Cr preserves the myogenic ability of oxidatively injured C2C12 via a pleiotropic mechanism involving not only its antioxidant capacity, but also the contribution to cell energy charge and effects at the transcriptional level which common bona fide antioxidants lack.

Cytoprotective effect of preparations from various parts of Punica granatum L. fruits in oxidatively injured mammalian cells in comparison with their antioxidant capacity in cell free systems.

Pomegranate (Punica granatum L.) juice (PJ) is being increasingly proposed as a nutritional supplement to prevent atherosclerosis in humans. This therapeutically valuable potential has been attributed to PJ antioxidant capacity which has been mostly tested by means of cell-free assays: indeed, to the best of our knowledge, no study has focused on the direct antioxidant capacity of PJ in cultured cells. Here, the antioxidant capacity in cell free-systems of preparations from various parts of pomegranate has been compared with their cytoprotective -bona fide antioxidant--activity in cultured human cells (U937 promonocytes and HUVEC endothelial cells) exposed to an array of oxidizing agents. Pomegranate derivatives were PJ, arils only juice (AJ) and aqueous rinds extract (RE). In cell-free assays--1,1-diphenyl-2-picrylhydrazyl (DPPH), chemiluminescence luminol/xanthine/xanthine oxidase and lipoxygenase assays--all the preparations displayed good antioxidant capacity, the relative potency order being RE>PJ>AJ. On the contrary, only RE was capable of preventing the deleterious effects--cytotoxicity, DNA damage and depletion of non-protein sulphydrils (NPSH) pool--caused by treatment of cells with H(2)O(2), tert-butylhydroperoxide (tB-OOH) or oxidized lipoproteins (Ox-LDL) via a mechanism which is likely to involve both direct scavenging of radical species and iron chelation. Surprisingly, AJ and PJ slightly sensitized cells to the cytotoxic effects of the three agents. Then it would appear that AJ, the major and tasty part of PJ, does not contain ellagic acid and punicalagin (i.e. the polyphenols highly represented in RE which are reputed to be responsible for the antioxidant capacity) in amounts sufficient to exert cytoprotection in oxidatively injured, living cells. Based on these results, the development and evaluation of rinds-only based derivatives for antiatherogenic preventive purposes in humans should be encouraged.

Creatine supplementation affords cytoprotection in oxidatively injured cultured mammalian cells via direct antioxidant activity.

A growing body of evidence suggests that creatine (Cr) might exert protective effects in a variety of pathologies where oxidative stress plays a concausal etiologic role; furthermore, it has been recently reported that Cr displays direct antioxidant activity in a cell-free setting. However, at present, no research has been specifically aimed to directly test the antioxidant potential of Cr on oxidatively injured cultured cells. Here, the effects of Cr were studied using cultured human promonocytic (U937) and endothelial (HUVEC) cells, and murine myoblasts (C2C12) exposed to H(2)O(2), tert-butylhydroperoxide (tB-OOH) and, in the case of U937 cells, peroxynitrite. Cr (0.1-10 mM) attenuated the cytotoxic effects caused by the oxidants in all the cell lines; under our conditions, cytoprotection was invariably associated with elevation of the intracellular fraction of Cr but it seemed to be unrelated to the levels of Cr phosphate (CrP); Cr did not affect the activity of catalase (CAT) and glutathione peroxidase (GpX), but it prevented H(2)O(2)- or tB-OOH-induced consumption of the nonprotein sulfhydryl (NPSH) pool in U937 and HUVEC cells; mass spectrometry experiments showed that a 136 MW molecule, which is likely to represent an oxidation by-product of Cr, formed in reaction buffers containing Cr and H(2)O(2) as well as in cellular extracts from H(2)O(2)- or tB-OOH- treated Cr-preloaded U937 cells; finally, Cr cytoprotection appeared to be unrelated to chelation of Fe(2+). In conclusion, it is suggested that Cr exerts a mild, although significant, antioxidant activity in living cells, via a mechanism depending on direct scavenging of reactive oxygen (in particular hydroxyl radical) and nitrogen species.