Trimetazidine improves exercise performance in patients with peripheral arterial disease

New insight of the efficacy trimetazidine in patients with peripheral arterial disease: a meta-analysis

BACKGROUND

This review aims to examine the impact of trimetazidine on skeletal muscle function in patients suffering from peripheral artery disease (PAD).

METHODS

We searched for studies, both experimental and observational research, concerning the comparison of trimetazidine administration to placebo/standard of care in patients with PAD in PubMed, ScienceDirect, and Cochrane. Meta-analyses of the included studies were performed using Review Manager v5.4. Clinical parameters [ankle-brachial index (ABI) and maximum walking distance (MWD)] were analyzed.

RESULTS

Three observational studies involving 378 participants with PAD satisfied predefined criteria. There was no substantial difference between the examined groups' on ABI (pre- and post-intervention) (MD = - 0.06 [- 0.19 to 0.07], p = 0.38, I2 = 90%). Meanwhile, MWD improvement was significantly higher (MD = 14.15 [6.05-22.25], p = 0.0006, I2 = 37%) in trimetazidine group than in the control group.

CONCLUSIONS

Current evidence from our meta-analysis suggests the beneficial role of trimetazidine's anti-ischemic effect in PAD patients by improving MWD, while it has an insignificant influence on ABI.

In-stent restenosis after percutaneous coronary intervention: emerging knowledge on biological pathways

Percutaneous coronary intervention (PCI) has evolved significantly over the past four decades. Since its inception, in-stent restenosis (ISR)-the progressive reduction in vessel lumen diameter after PCI-has emerged as the main complication of the procedure. Although the incidence of ISR has reduced from 30% at 6 months with bare-metal stents to 7% at 4 years with drug-eluting stents (DESs), its occurrence is relevant in absolute terms because of the dimensions of the population treated with PCI. The aim of this review is to summarize the emerging understanding of the biological pathways that underlie ISR. In-stent restenosis is associated with several factors, including patient-related, genetic, anatomic, stent, lesion, and procedural characteristics. Regardless of associated factors, there are common pathophysiological pathways involving molecular phenomena triggered by the mechanical trauma caused by PCI. Such biological pathways are responses to the denudation of the intima during balloon angioplasty and involve inflammation, hypersensitivity reactions, and stem cell mobilization particularly of endothelial progenitor cells (EPCs). The results of these processes are either vessel wall healing or neointimal hyperplasia and/or neo-atherosclerosis. Unravelling the key molecular and signal pathways involved in ISR is crucial to identify appropriate therapeutic strategies aimed at abolishing the 'Achille's heel' of PCI. In this regard, we discuss novel approaches to prevent DES restenosis. Indeed, available evidence suggests that EPC-capturing stents promote rapid stent re-endothelization, which, in turn, has the potential to decrease the risk of stent thrombosis and allow the use of a shorter-duration dual antiplatelet therapy.

Ranolazine Counteracts Strength Impairment and Oxidative Stress in Aged Sarcopenic Mice

Sarcopenia is defined as the loss of muscle mass associated with reduced strength leading to poor quality of life in elderly people. The decline of skeletal muscle performance is characterized by bioenergetic impairment and severe oxidative stress, and does not always strictly correlate with muscle mass loss. We chose to investigate the ability of the metabolic modulator Ranolazine to counteract skeletal muscle dysfunctions that occur with aging. For this purpose, we treated aged C57BL/6 mice with Ranolazine/vehicle for 14 days and collected the tibialis anterior and gastrocnemius muscles for histological and gene expression analyses, respectively. We found that Ranolazine treatment significantly increased the muscle strength of aged mice. At the histological level, we found an increase in centrally nucleated fibers associated with an up-regulation of genes encoding MyoD, Periostin and Osteopontin, thus suggesting a remodeling of the muscle even in the absence of physical exercise. Notably, these beneficial effects of Ranolazine were also accompanied by an up-regulation of antioxidant and mitochondrial genes as well as of NADH-dehydrogenase activity, together with a more efficient protection from oxidative damage in the skeletal muscle. These data indicate that the protection of muscle from oxidative stress by Ranolazine might represent a valuable approach to increase skeletal muscle strength in elderly populations.

Newly discovered molecules associated with trimetazidine on improvement of skeletal muscle function in aging: evidence from myoblasts and mice

Poor muscle function is increasingly obvious with aging and needs effective and safe medicine for treatment. Trimetazidine (TMZ) has potential benefits for the condition but has not yet been fully recognized. In the randomized-control pilot study part, fifty-three old patients were assigned to the TMZ group or control group. For the TMZ group, a dose of 35 mg of oral TMZ was administered with a meal twice a day for 3 months. Only conventional treatments were administrated in the control group. Muscle strength, gait speed, muscle endurance, and balance maintenance were measured during the visits. In the experiments part, thirty mice were screened and randomly assigned to three groups: model group received a D-gal (500 mg/kg) intraperitoneal injection every two days for six weeks, the control group received saline at the same condition, and the intervention group received 5 mg/kg TMZ solution every two days by gavage for two weeks. Swimming tests and forelimb grip strength measurements were also performed. Furthermore, significantly clustered profiles from differentially expressed genes were found by RNA-seq and verified by qRT-PCR and WB. Myofiber analyses were done by H&E staining. Here, we found the improvement of skeletal performance in aged individuals and aged mouse. The dominant handgrip strength (HS) was increased by 24.4% and dominant pinch strength (PS) by 12.4% in participants with TMZ modified-release tablets consumption. Exhaustive time was increased by 23.6% and upper limb grip strength by 44.1% in aged mouse with TMZ-treated. Besides, we also identified some newly discovered molecules associated with TMZ on muscle function improvement during aging. To aged C2C12 cells and aged mouse muscle, TMZ-treated was related to a statistically significant decrease in the expressions of NOS3 and MMP-9, but a statistically significant increase in the expressions of OMD and MyoG. In summary, TMZ modified-release tablets can improve the muscle strength of elderly patients. Besides, the improvement of skeletal muscle function affected by TMZ was associated with reducing NOS3 expression in senescent myoblasts.

Trimetazidine ameliorates hindlimb ischaemic damage in type 2 diabetic mice

BACKGROUND

Ischaemia caused by lower extremity artery stenosis is the main cause of peripheral artery disease (PAD) in patients with diabetes. Trimetazidine (TMZ) has traditionally been used as an anti-ischaemic drug for coronary artery disease. The effect of TMZ on PAD in a diabetic animal model and the underlying molecular mechanisms remain unclear.

METHODS

The db/db mice were challenged with femoral artery ligation (FAL), followed by TMZ treatment for 2 weeks. Scores on hindlimb ischaemia and function were evaluated. Histological and capillary density analyses of gastrocnemius were performed. The expression of vascular endothelial growth factor (VEGF) and myogenic regulators was also confirmed by Western blotting. We also detected serum intercellular adhesion molecule 1 (ICAM-1) level through ELISA.

RESULTS

Diabetic mice exhibited limb ulceration and motor dysfunction after FAL while TMZ-treated db/db mice exhibited milder ischaemic impairment. Furthermore, decreased capillary density in the gastrocnemius muscles of ischaemic hindlimb and reduced expressions of VEGF, myogenic markers, and serum ICAM-1 could be partially reversed by TMZ treatment.

CONCLUSION

TMZ may alleviate hindlimb ischaemic damage in db/db mice, at least partly, through enhancing angiogenesis and promoting myogenesis in ischaemia region.Key messagesTMZ intervention could alleviate hindlimb ischaemic damage in db/db mice.TMZ intervention could enhance angiogenesis and stimulate myogenesis in ischaemia region.

Trimetazidine attenuates dexamethasone-induced muscle atrophy via inhibiting NLRP3/GSDMD pathway-mediated pyroptosis

Skeletal muscle atrophy is one of the major side effects of high dose or sustained usage of glucocorticoids. Pyroptosis is a novel form of pro-inflammatory programmed cell death that may contribute to skeletal muscle injury. Trimetazidine, a well-known anti-anginal agent, can improve skeletal muscle performance both in humans and mice. We here showed that dexamethasone-induced atrophy, as evidenced by the increase of muscle atrophy F-box (Atrogin-1) and muscle ring finger 1 (MuRF1) expression, and the decrease of myotube diameter in C2C12 myotubes. Dexamethasone also induced pyroptosis, indicated by upregulated pyroptosis-related protein NLR family pyrin domain containing 3 (NLRP3), Caspase-1, and gasdermin-D (GSDMD). Knockdown of NLRP3 or GSDMD attenuated dexamethasone-induced myotube pyroptosis and atrophy. Trimetazidine treatment ameliorated dexamethasone-induced muscle pyroptosis and atrophy both in vivo and in vitro. Activation of NLRP3 using LPS and ATP not only increased the cleavage and activation of Caspase-1 and GSDMD, but also increased the expression levels of atrophy markers MuRF1 and Atrogin-1 in trimetazidine-treated C2C12 myotubes. Mechanically, dexamethasone inhibited the phosphorylation of PI3K/AKT/FoxO3a, which could be attenuated by trimetazidine. Conversely, co-treatment with a PI3K/AKT inhibitor, picropodophyllin, remarkably increased the expression of NLRP3 and reversed the protective effects of trimetazidine against dexamethasone-induced C2C12 myotube pyroptosis and atrophy. Taken together, our study suggests that NLRP3/GSDMD-mediated pyroptosis might be a novel mechanism for dexamethasone-induced skeletal muscle atrophy. Trimetazidine might be developed as a potential therapeutic agent for the treatment of dexamethasone-induced muscle atrophy.

The Inclusion in WADA Prohibited List Is Not Always Supported by Scientific Evidence: A Narrative Review

Context: Our goal was to review the current literature regarding the ability of substances that have recently been included in the WADA prohibited list (i.e., meldonium, trimetazidine, xenon, and cobalt) or in the monitoring program (i.e., ecdysterone and bemethyl) to enhance performance in athletes or cause adverse effects. Evidence Acquisition: To find out which studies led to the prohibition of the substances mentioned, we searched the PubMed database using keywords including the substances’ or methods’ names, as well as phrases related to various aspects of sports activities and health assessments of athletes. Results: The results obtained during our systematic literature search clearly indicate that there is a lack of scientific evidence supporting the impact of several substances prohibited by WADA (i.e., meldonium, trimetazidine, xenon, and cobalt) on athletic performance or on health in athletes. Conclusions: There is insufficient evidence that the previously mentioned substances have any performance enhancing potential. If left on the list, meldonium may be classified as a “specified substance” because of its wide availability and due to the fact that this drug that can be easily bought over the counter without a prescription.

Review of WADA Prohibited Substances: Limited Evidence for Performance-Enhancing Effects

The World Anti-Doping Agency is responsible for maintaining a Prohibited List that describes the use of substances and methods that are prohibited for athletes. The list currently contains 23 substance classes, and an important reason for the existence of this list is to prevent unfair competition due to pharmacologically enhanced performance. The aim of this review was to give an overview of the available evidence for performance enhancement of these substance classes. We searched the scientific literature through PubMed for studies and reviews evaluating the effects of substance classes on performance. Findings from double-blind, randomized controlled trials were considered as evidence for (the absence of) effects if they were performed in trained subjects measuring relevant performance outcomes. Only 5 of 23 substance classes show evidence of having the ability to enhance actual sports performance, i.e. anabolic agents, β2-agonists, stimulants, glucocorticoids and β-blockers. One additional class, growth hormone, has similar evidence but only in untrained subjects. The observed effects all relate to strength or sprint performance (and accuracy for β-blockers); there are no studies showing positive effects on reliable markers of endurance performance. For 11 classes, no well-designed studies are available, and, for the remaining six classes, there is evidence of an absence of a positive effect. In conclusion, for the majority of substance classes, no convincing evidence for performance enhancement is available, while, for the remaining classes, the evidence is based on a total of only 266 subjects from 11 studies.

Targeting mitochondria for cardiovascular disorders: therapeutic potential and obstacles

A large body of evidence indicates that mitochondrial dysfunction has a major role in the pathogenesis of multiple cardiovascular disorders. Over the past 2 decades, extraordinary efforts have been focused on the development of agents that specifically target mitochondria for the treatment of cardiovascular disease. Despite such an intensive wave of investigation, no drugs specifically conceived to modulate mitochondrial functions are currently available for the clinical management of cardiovascular disease. In this Review, we discuss the therapeutic potential of targeting mitochondria in patients with cardiovascular disease, examine the obstacles that have restrained the development of mitochondria-targeting agents thus far, and identify strategies that might empower the full clinical potential of this approach.

Trimetazidine in angina and poor muscle function: protocol for a randomized controlled study

BACKGROUND

Low handgrip strength (HS) and declining gait speed (GS) are increasingly obvious with aging, requiring effective, and safe medication for treatment. Trimetazidine (TMZ) modified release tablets, a common anti-angina drug, has potential benefits for alleviating the condition, but this has not yet been fully studied and therefore is the aim of this study.

METHODS

This is a prospective randomized controlled study. Fifty-eight eligible patients will be randomly assigned to one of two study groups: TMZ group or control group. For the TMZ group, a dose of 35 mg of oral TMZ will be administered with a meal twice a day for 3 months, in addition to any conventional treatments for angina. Only conventional treatments for angina will be administrated in the control group. The primary outcome will be the 6-min walking distance and the secondary outcomes will be: muscle strength (HS and pinch strength), GS, muscle endurance (five times sit-to-stand test), balance maintenance (tandem standing test), and the frequency of angina per week. Additionally, body mass index, circumferences (biceps, waist, hip, and calf), albumin levels, and the score on a five-question scale for sarcopenia will be obtained during the study.

DISCUSSION

This study aims to evaluate the usefulness of TMZ in a population with poor muscle function. The results may provide an effective and safe medical treatment to people with low muscle strength or physical performance.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1800015000; www.chictr.org.cn/showproj.aspx?proj=25445.

Trimetazidine combined with exercise improves exercise capacity and anti-fatal stress ability through enhancing mitochondrial quality control

AIMS

To explore the effects of trimetazidine combined with exercise on EC and anti-fatal stress ability, and illustrate the underlying mechanism.

METHODS

C57BL/6 mice were randomly assigned to four groups (n = 11 in each group): the control, exercise, trimetazidine and trimetazidine + exercise (TE) groups. Mice were accordingly given saline (ig), Aerobic exercise (AE), trimetazidine (ig), or a combination of trimetazidine (ig) and AE for five weeks. After the intervention, each group was randomly subdivided into rest and exhaustive exercise (EE) subgroups. The mice in the control-EE and TE-EE subgroups underwent fatal stress experiments. EC and anti-fatal stress ability were assessed respectively. Mitochondrial quality control (MQC) in skeletal muscle were measured at the protein level and the organelle level.

KEY FINDINGS

A significantly increased exhaustive swimming time was observed in exercise (39.10 ± 12.58 min vs 14.18 ± 4.37 min), trimetazidine (33.73 ± 8.45 min vs 14.18 ± 4.37 min) and TE groups (73.78 ± 18.95 min vs 14.18 ± 4.37 min) compared with that in the control group, and a synergistic effect was detected (P < 0.05). Fatal stress experiments successfully induced skeletal muscle damage, including increased creatine kinase activity, myofibrosis, and impaired antioxidative enzyme system, all those were significantly alleviated by trimetazidine supplementation combined with AE precondition (P < 0.05). Meanwhile, AE and trimetazidine alone or combined, significantly enhanced the MQC in normal mice by activating mitochondrial biogenesis, dynamics and mitophagy, and that in mice underwent fatal stress stimulus (P < 0.05).

SIGNIFICANCE

This study for the first time found that trimetazidine and AE have synergistic effects on improving EC. Moreover, the combination of both interventions enhances anti-fatal stress ability. Enhancing MQC may be a key mechanism of AE combined with trimetazidine that improves EC and anti-fatal stress ability.

Trimetazidine Protects Against Atherosclerosis by Changing Energy Charge and Oxidative Stress

BACKGROUND This study investigated the effect and the possible mechanism of trimetazidine in atherosclerosis. MATERIAL AND METHODS We established an atherosclerotic rat model by high-fat diet and vitamin D injection. Rats were separated into 3 different groups: control, atherosclerosis, and trimetazidine (n=10). The aortic artery was isolated and its morphological features were examined by hematoxylin and eosin (HE) staining. Serum low-density lipoprotein cholesterol (LDL-c), total cholesterol (TC), and triglycerides (TG) were analyzed using an automatic biochemical analyzer. Human aortic smooth muscle cells (HASMCs) were cultured and divided into 5 groups: no treatment, H₂O₂ treatment only, trimetazidine preincubation before H₂O₂ treatment, oxidized low-density lipoprotein (oxLDL) treatment only, and trimetazidine preincubation before oxLDL treatment. HASMCs proliferation was tested using the Cell Counting Kit-8. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity of the aortic artery, and HASMCs were measured using commercially available kits. RESULTS HE staining assay showed that trimetazidine suppressed the progression of atherosclerosis and reduced foam cell formation in the aortic artery without affecting serum lipid levels. HASMCs proliferation assay revealed that trimetazidine alleviated the inhibitory effect of H₂O₂ on HASMCs proliferation and inhibited oxLDL-induced proliferation of HASMCs. Moreover, trimetazidine ameliorated ROS up-regulation elicited by H₂O₂ or oxLDL in HASMCs. Additionally, trimetazidine restored SOD activity and reduced MDA content of HASMCs. CONCLUSIONS Trimetazidine suppressed the progression of atherosclerosis by enhancing energy value, decreasing ROS level of aortic artery, modulating HASMCs proliferation, and reducing oxidative stress in HASMCs.

Modulating Metabolism to Improve Cancer-Induced Muscle Wasting

Muscle wasting is one of the main features of cancer cachexia, a multifactorial syndrome frequently occurring in oncologic patients. The onset of cachexia is associated with reduced tolerance and response to antineoplastic treatments, eventually leading to clinical conditions that are not compatible with survival. Among the mechanisms underlying cachexia, protein and energy dysmetabolism play a major role. In this regard, several potential treatments have been proposed, mainly on the basis of promising results obtained in preclinical models. However, at present, no treatment yet reached validation to be used in the clinical practice, although several drugs are currently tested in clinical trials for their ability to improve muscle metabolism in cancer patients. Along this line, the results obtained in both experimental and clinical studies clearly show that cachexia can be effectively approached by a multidirectional strategy targeting nutrition, inflammation, catabolism, and inactivity at the same time. In the present study, approaches aimed to modulate muscle metabolism in cachexia will be reviewed.

The mitochondrial metabolic reprogramming agent trimetazidine as an 'exercise mimetic' in cachectic C26-bearing mice

BACKGROUND

Cancer cachexia is characterized by muscle depletion and exercise intolerance caused by an imbalance between protein synthesis and degradation and by impaired myogenesis. Myofibre metabolic efficiency is crucial so as to assure optimal muscle function. Some drugs are able to reprogram cell metabolism and, in some cases, to enhance metabolic efficiency. Based on these premises, we chose to investigate the ability of the metabolic modulator trimetazidine (TMZ) to counteract skeletal muscle dysfunctions and wasting occurring in cancer cachexia.

METHODS

For this purpose, we used mice bearing the C26 colon carcinoma as a model of cancer cachexia. Mice received 5 mg/kg TMZ (i.p.) once a day for 12 consecutive days. A forelimb grip strength test was performed and tibialis anterior, and gastrocnemius muscles were excised for analysis. Ex vivo measurement of skeletal muscle contractile properties was also performed.

RESULTS

Our data showed that TMZ induces some effects typically achieved through exercise, among which is grip strength increase, an enhanced fast-to slow myofibre phenotype shift, reduced glycaemia, PGC1α up-regulation, oxidative metabolism, and mitochondrial biogenesis. TMZ also partially restores the myofibre cross-sectional area in C26-bearing mice, while modulation of autophagy and apoptosis were excluded as mediators of TMZ effects.

CONCLUSIONS

In conclusion, our data show that TMZ acts like an 'exercise mimetic' and is able to enhance some mechanisms of adaptation to stress in cancer cachexia. This makes the modulation of the metabolism, and in particular TMZ, a suitable candidate for a therapeutic rehabilitative protocol design, particularly considering that TMZ has already been approved for clinical use.

Effectiveness and safety of anti-ischemic trimetazidine in patients with stable angina pectoris and Type 2 diabetes

Aim & methods: This 6-month prospective, observational, noninterventional, open-label clinical study assessed the effectiveness/safety of trimetazidine in 737 patients with stable angina pectoris and Type 2 diabetes mellitus (OGYI/51534–1/2014). Results: Trimetazidine-based therapy was effective in stable coronary artery disease, with significant improvements from baseline (p < 0.05) in: number of angina attacks/week (2.9 ± 2.4 vs 1.1 ± 1.6), angina severity (Canadian Cardiovascular Society Classification 1.9 ± 0.8 vs 1.2 ± 0.8), exercise capacity (metabolic equivalents 6.1 ± 1.7 vs 6.5 ± 1.7), and exercise-induced myocardial ischemia (min 5.5 ± 2.5 vs 6.5 ± 2.6). Discussion: Trimetazidine treatment significantly (p < 0.05) improved glucose metabolism, lowered HbA1c (7.1 ± 1.1% vs 6.6 ± 1.0%), glucose levels (7.7 ± 2.1 mmol/l vs 6.9 ± 1.6 mmol/l) and decreased arterial stiffness (pulse wave velocity 11.2 ± 2.1 m/s vs 10.4 ± 2.2 m/s). In most patients, the tolerability of trimetazidine was rated as excellent to good, with a low incidence of adverse events.

Improvement of skeletal muscle performance in ageing by the metabolic modulator Trimetazidine

BACKGROUND

The loss of muscle mass (sarcopenia) and the associated reduced muscle strength are key limiting factors for elderly people's quality of life. Improving muscle performance does not necessarily correlate with increasing muscle mass. In fact, particularly in the elderly, the main explanation for muscle weakness is a reduction of muscle quality rather than a loss of muscle mass, and the main goal to be achieved is to increase muscle strength. The effectiveness of Trimetazidine (TMZ) in preventing muscle functional impairment during ageing was assessed in our laboratory.

METHODS

Aged mice received TMZ or vehicle for 12 consecutive days. Muscle function was evaluated at the end of the treatment by a grip test as well as by an inverted screen test at 0, 5, 7 and 12 days of TMZ treatment. After sacrifice, muscles were stored for myofiber cross-sectional area assessment and myosin heavy chain expression evaluation by western blotting.

RESULTS

Chronic TMZ treatment does not affect the mass of both gastrocnemius and tibialis anterior muscles, while it significantly increases muscle strength. Indeed, both latency to fall and grip force are markedly enhanced in TMZ-treated versus untreated mice. In addition, TMZ administration results in higher expression of slow myosin heavy chain isoform and increased number of small-sized myofibers.

CONCLUSIONS

We report here some data showing that the modulation of skeletal muscle metabolism by TMZ increases muscle strength in aged mice. Reprogramming metabolism might therefore be a strategy worth to be further investigated in view of improving muscle performance in the elderly.

Defining the role of trimetazidine in the treatment of cardiovascular disorders: some insights on its role in heart failure and peripheral artery disease

Trimetazidine is a cytoprotective drug whose cardiovascular effectiveness, especially in patients with stable ischemic heart disease, has been the source of much controversy in recent years; some have gone so far as to treat the medication as a ‘placebo drug’ whose new side effects, such as Parkinsonian symptoms, outweigh its benefits. This article is an attempt to present the recent key studies, including meta-analyses, on the use of trimetazidine in chronic heart failure, also in patients with diabetes mellitus and arrhythmia, as well as in peripheral artery disease. This paper also includes the most recent European Society of Cardiology guidelines, including those of 2013, on the use of trimetazidine in cardiovascular disease.

Exercise-induced skeletal muscle remodeling and metabolic adaptation: redox signaling and role of autophagy

SIGNIFICANCE

Skeletal muscle is a highly plastic tissue. Exercise evokes signaling pathways that strongly modify myofiber metabolism and physiological and contractile properties of skeletal muscle. Regular physical activity is beneficial for health and is highly recommended for the prevention of several chronic conditions. In this review, we have focused our attention on the pathways that are known to mediate physical training-induced plasticity.

RECENT ADVANCES

An important role for redox signaling has recently been proposed in exercise-mediated muscle remodeling and peroxisome proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) activation. Still more currently, autophagy has also been found to be involved in metabolic adaptation to exercise.

CRITICAL ISSUES

Both redox signaling and autophagy are processes with ambivalent effects; they can be detrimental and beneficial, depending on their delicate balance. As such, understanding their role in the chain of events induced by exercise and leading to skeletal muscle remodeling is a very complicated matter. Moreover, the study of the signaling induced by exercise is made even more difficult by the fact that exercise can be performed with several different modalities, with this having different repercussions on adaptation.

FUTURE DIRECTIONS

Unraveling the complexity of the molecular signaling triggered by exercise on skeletal muscle is crucial in order to define the therapeutic potentiality of physical training and to identify new pharmacological compounds that are able to reproduce some beneficial effects of exercise. In evaluating the effect of new "exercise mimetics," it will also be necessary to take into account the involvement of reactive oxygen species, reactive nitrogen species, and autophagy and their controversial effects.

The metabolic modulator trimetazidine triggers autophagy and counteracts stress-induced atrophy in skeletal muscle myotubes

It has recently been demonstrated that trimetazidine (TMZ), an anti-ischemic antianginal agent, is also able to improve exercise performance in patients with peripheral arterial disease. TMZ is a metabolic modulator, and the mechanisms underlying its cytoprotective anti-ischemic activity could be ascribed, at least in cardiomyocytes, to optimization of metabolism. However, regarding the cytoprotection exerted by TMZ on skeletal muscle and allowing the improvement of exercise performance, no information is yet available. In the present study, we investigated in detail the protective effects of this drug on in vitro skeletal muscle models of atrophy. Experiments carried out with murine C2C12 myotubes treated with TMZ revealed that this drug could efficiently counteract the cytopathic effects induced by the proinflammatory cytokine tumor necrosis factor-α and by the withdrawal of growth factors. Indeed, TMZ significantly counteracted the reduction in myotube size induced by these treatments. TMZ also increased myosin heavy chain expression and induced hypertrophy in C2C12 myotubes, both effects strongly suggesting a role of TMZ in counteracting atrophy in vitro. In particular, we found that TMZ was able to activate the phosphoinositide 3-kinase-Akt-mammalian target of rapamycin 2 pathway and to reduce the stress-induced transcriptional upregulation of atrogin-1, muscle ring finger protein 1, and myostatin, all of which are key molecules involved in muscle wasting. Moreover, this is the first demonstration that TMZ induces autophagy, a key mechanism involved in muscle mass regulation. On the basis of these results, it can be hypothesized that the improvement in exercise performance previously observed in patients could be ascribed to a cytoprotective mechanism exerted by TMZ on skeletal muscle integrity.

Current evidence and future perspectives on n-3 PUFAs

The family of polyunsaturated fatty acids (PUFAs), which can be found in most lipid classes, includes n-3 PUFAs essential for mammals and whose deficiency is associated with multiple diseases. Because of their multiple physiological actions, n-3 PUFAs play a crucial role in normal human metabolism as well as maintenance of a healthy status, with clinical effects that are not limited to the cardiovascular system but also include maternal and offspring health, growth and development, immune system disorders, cancer, cognitive function and psychological status. Multiple health organisations and scientific societies recommend increasing food-derived n-3 PUFA intake and also suggest that patients with documented coronary heart disease receive a minimum of 1000 mg/day of eicosapentaenoic acid and docosahexaenoic acid. The preventive and therapeutic effects of n-3 PUFAs appear to be largely dependent on the dosages employed and the characteristics of selected patients. So, in the era of personalised medicine, the time has come to move from generic advice to increase n-3 PUFA intake to a more evidence-based approach characterised by tailored indications to n-3 PUFA dietary or supplement consumption. This approach will require evaluation on a case-to-case basis the potential usefulness of n-3 PUFAs, taking into consideration their 'pleiotropic effects', the optimal dose for any given indication in relation to international guidelines, potential interactions with background therapy, possible side effects, differences in genetics and dietary response to supplementation, and the cost:benefit ratio, which is likely to vary as a function of differences in the range of fish intake in the diet.

The effect of trimetazidine on cardiac function in diabetic patients with idiopathic dilated cardiomyopathy

AIMS

Trimetazidine is an anti-ischemic metabolic agent which improves myocardial glucose utilization. Whether it may improve cardiac function and physical tolerance in diabetic patients with idiopathic dilated cardiomyopathy is still not confirmed. In this study we have investigated the effectiveness of trimetazidine in these patients.

MAIN METHODS

Volunteers with diabetes and idiopathic dilated cardiomyopathy were recruited for participation in this study. Patients were randomized into two groups. One group received trimetazidine (20mg, t.i.d.) for 6 months (n=40), while another group received a placebo during the same period (n=40). All patients received an echocardiographic examination, 6-minute walk test and an inflammation biochemical analysis (C reactive protein) at baseline and after 6 months of treatment.

KEY FINDINGS

No significant adverse events or changes in clinical or biochemical parameters were detected through the study. After 6 months, TMZ-treated patients had a significant improvement in systolic function as compared with control patients associated with an increased ratio of E/A. C reactive protein concentrations remained stable throughout the study in trimetazidine group at baseline and at the 6 month on follow up. In comparison, it increased significantly in the control group at the 6-month follow up. The NT-pro BNP levels did not change in the control group, whereas they significantly decreased in the trimetazidine group. The physical activity tolerance level improved in the trimetazidine group compared to the control group.

SIGNIFICANCE

Trimetazidine treatment was associated with a significant improvement of cardiac function and physical tolerance. Results also suggested that the inflammatory response was decreased in trimetazidine group as compared with control patients.