Breakthrough in cachexia treatment through a novel selective androgen receptor modulator?!

Effects Of Oxandrolone On Lean Body Mass (Lbm) In Severe Burn Patients: A Randomized, Double Blind, Placebo-Controlled Trial

In severe burns, hyper-metabolic conditions due to elevation of pro-inflammatory cytokines and stress hormones usually occur. Unregulated hypermetabolism can lead to muscle protein catabolism, inducing weakness, infection, and delayed wound healing. Oxandrolone is known as an anabolic agent with minor side effects. This study aims to determine the effect of oxandrolone on lean body mass (LBM) in severe burn patients. A randomized, double blind and placebo controlled trial was conducted in the burn centre of the Dr. Soetomo Hospital. Severe burn patients who met the inclusion criteria were randomized into two groups, oxandrolone and placebo group. Oxandrolone was given with a dose 0.1 mg/kg twice a day for 14 consecutive days. Estimated lean body mass (eLBM) for each group was measured on admission (day 0) and day 14. Fourteen burn patients were enrolled in this study. Lean body mass reduced significantly from 48.69±7.71 to 46.70±7.96 in the placebo group (p-value 0.008) by independent t-test. There was no significant decrease of LBM in the oxandrolone group. Delta LBM (Δ eLBM) before and after treatment was 0.38±1.64 in the oxandrolone group, and -1.32±1.23 in the placebo group (p-value = 0.049). There were no adverse effects during the administration to the oxandrolone group. In severe burn patients, oxandrolone could prevent reduction of LBM compared to placebo and is relatively safe. These findings suggest the efficacy of oxandrolone in preventing muscle catabolism as a part of hypermetabolism in burn patients.

Does perioperative oxandrolone improve nutritional status in patients with cachexia related to head and neck carcinoma?

Background

Cancer cachexia affects up to over 50% of advanced head and neck cancer (HNC) patients. To date, the potential utility of anabolic steroids in perioperative cachectic HNC patients has not been determined.

Methods

Retrospective review of pre- and post-oxandrolone administration prealbumin levels in 18 perioperative HNC patients between October 2007 and October 2014 at a tertiary academic medical center.

Results

The median pretreatment prealbumin was 88.5 mg/L. The median post-treatment prealbumin was 227 mg/L. The median interval improvement of the prealbumin level was 131.5 mg/L. The median differences between the pretreatment and post-treatment prealbumin levels were found to be statistically significant (P < .001). Subjective improvement in wound healing was also observed.

Conclusions

Perioperative administration of oxandrolone resulted in objective improvements in prealbumin levels and subjective improvements in surgical wounds. Oxandrolone administered 10 mg twice daily (BID) for 10 days may be a useful adjunct in the perioperative care of nutritionally deficient HNC patients who are at risk for or have demonstrated impaired wound healing.

Level of Evidence

3.

Myricanol rescues dexamethasone-induced muscle dysfunction via a sirtuin 1-dependent mechanism

BACKGROUND

Muscle atrophy and weakness are adverse effects of high dose or the sustained usage of glucocorticoids. Loss of mitochondria and degradation of protein are highly correlated with muscle dysfunction. The deacetylase sirtuin 1 (SIRT1) plays a vital role in muscle remodelling. The current study was designed to identify myricanol as a SIRT1 activator, which could protect skeletal muscle against dexamethasone-induced wasting.

METHODS

The dexamethasone-induced atrophy in C2C12 myotubes was evaluated by expression of myosin heavy chain, muscle atrophy F-box (atrogin-1), and muscle ring finger 1 (MuRF1), using western blots. The mitochondrial content and oxygen consumption were assessed by MitoTracker staining and extracellular flux analysis, respectively. Muscle dysfunction was established in male C57BL/6 mice (8-10 weeks old, n = 6) treated with a relatively high dose of dexamethasone (25 mg/kg body weight, i.p., 10 days). Body weight, grip strength, forced swimming capacity, muscle weight, and muscle histology were assessed. The expression of proteolysis-related, autophagy-related, apoptosis-related, and mitochondria-related proteins was analysed by western blots or immunoprecipitation.

RESULTS

Myricanol (10 μM) was found to rescue dexamethasone-induced muscle atrophy and dysfunction in C2C12 myotubes, indicated by increased expression of myosin heavy chain (0.33 ± 0.14 vs. 0.89 ± 0.21, *P < 0.05), decreased expression of atrogin-1 (2.31 ± 0.67 vs. 1.53 ± 0.25, *P < 0.05) and MuRF1 (1.55 ± 0.08 vs. 0.99 ± 0.12, **P < 0.01), and elevated ATP production (3.83 ± 0.46 vs. 5.84 ± 0.79 nM/mg protein, **P < 0.01), mitochondrial content (68.12 ± 10.07% vs. 116.38 ± 5.12%, *P < 0.05), and mitochondrial oxygen consumption (166.59 ± 22.89 vs. 223.77 ± 22.59 pmol/min, **P < 0.01). Myricanol directly binds and activates SIRT1, with binding energy of -5.87 kcal/mol. Through activating SIRT1 deacetylation, myricanol inhibits forkhead box O 3a transcriptional activity to reduce protein degradation, induces autophagy to enhance degraded protein clearance, and increases peroxisome proliferator-activated receptor γ coactivator-1α activity to promote mitochondrial biogenesis. In dexamethasone-induced muscle wasting C57BL/6 mice, 5 mg/kg myricanol treatment reduces the loss of muscle mass; the percentages of quadriceps and gastrocnemius muscle in myricanol-treated mice are 1.36 ± 0.02% and 0.87 ± 0.08%, respectively (cf. 1.18 ± 0.06% and 0.78 ± 0.05% in dexamethasone-treated mice, respectively). Myricanol also rescues dexamethasone-induced muscle weakness, indicated by improved grip strength (70.90 ± 4.59 vs. 120.58 ± 7.93 g, **P < 0.01) and prolonged swimming exhaustive time (48.80 ± 11.43 vs. 83.75 ± 15.19 s, **P < 0.01). Myricanol prevents dexamethasone-induced muscle atrophy and weakness by activating SIRT1, to reduce muscle protein degradation, enhance autophagy, and promote mitochondrial biogenesis and function in mice.

CONCLUSIONS

Myricanol ameliorates dexamethasone-induced skeletal muscle wasting by activating SIRT1, which might be developed as a therapeutic agent for treatment of muscle atrophy and weakness.

Expanding sports drug testing assays: mass spectrometric characterization of the selective androgen receptor modulator drug candidates RAD140 and ACP-105

RATIONALE

Anabolic agents have been top-ranked for many years among statistics of adverse analytical findings compiled by the World Anti-Doping Agency (WADA). Besides archetypical anabolic-androgenic steroids (AAS), alternative substances with similar effects concerning bone and muscle anabolism have been therapeutically pursued. A prominent emerging class of drugs is the chemically heterogeneous group of selective androgen receptor modulators (SARMs), some of which have been detected in doping control samples between 2009 and 2012 despite missing clinical approval.

METHODS

In order to support the momentum of expanding the preventive and proactive measures among anti-doping laboratories, the analytical characterization of substances with misuse potential is of great importance. In the present study, the SARM drug candidates RAD140 (comprising a 5-phenyloxadiazole nucleus) and ACP-105 (bearing an N-substituted tropanol pharmacophore) were studied regarding their mass spectrometric behavior under ESI-MS(/MS) and EI-MS(/MS) conditions. Reference material was synthesized according to established protocols and dissociation pathways of RAD140 and ACP-105 were elucidated with liquid chromatography/electrospray ionization quadrupole/time-of-flight or iontrap/orbitrap and gas chromatography/electron ionization quadrupole/time-of-flight high resolution/high accuracy mass spectrometry.

RESULTS

Fragmentation pathways to diagnostic product ions of RAD140 (e.g. m/z 223 and 205 using ESI-MS/MS and m/z 421 and 349 using EI-MS/MS) and ACP-105 (such as m/z 233 and 193 or 231 and 217 for ESI-MS/MS and EI-MS/MS measurements, respectively) were proposed as substantiated by determined elemental compositions and MS(n) experiments as well as comparison to spectra of a structural analog. Notably, for the formation of the characteristic fragment ion at m/z 421 of RAD140, the comparably seldom intramolecular migration of a trimethylsilyl residue triggered by electron ionization was suggested as corroborated by all of the above-mentioned analytical means.

CONCLUSIONS

The obtained data will support future sports drug testing methods and facilitate and accelerate the implementation of this analyte and related compounds or metabolites in both GC/MS(/MS)- and LC/MS(/MS)-based routine doping control procedures.

Mechanism and novel therapeutic approaches to wasting in chronic disease

Cachexia is a multifactorial syndrome defined by continuous loss of skeletal muscle mass - with or without loss of fat mass - which cannot be fully reversed by conventional nutritional support and which may lead to progressive functional impairment and increased death risk. Its pathophysiology is characterized by negative protein and energy balance driven by a variable combination of reduced food intake and abnormal metabolism. Muscle wasting is encountered in virtually all chronic disease states in particular during advanced stages of the respective illness. Several pre-clinical and clinical studies are ongoing to ameliorate this clinical problem. The mechanisms of muscle wasting and cachexia in chronic diseases such as cancer, chronic heart failure, chronic obstructive pulmonary disease and chronic kidney disease are described. We discuss therapeutic targets and such potential modulators as appetite stimulants, selective androgen receptor modulators, amino acids and naturally occurring peptide hormones.

Highlights of mechanistic and therapeutic cachexia and sarcopenia research 2010 to 2012 and their relevance for cardiology

Sarcopenia and cachexia are significant medical problems with a high disease-related burden in cardiovascular illness. Muscle wasting and weight loss are very frequent particularly in chronic heart failure and they relate to poor prognosis. Although clinically largely underestimated, the fields of cachexia and sarcopenia are of great relevance to cardiologists. In cachexia and sarcopenia a significant number of research publications related to basic science questions of muscle wasting and lipolysis were published between 2010 and 2012. Recently, the two processes of muscle wasting and lipolysis were found to be closely linked. Treatment research in pre-clinical models involves studies on a number of different therapeutic entities, including ghrelin, selective androgen receptor modulators (SARMs), as well as drugs targeting myostatin or melanocortin-4. In the human setting, studies using enobosarm (a SARM) and anamorelin (ghrelin) are in phase III. The last 3 years have seen significant efforts to define the field using consensus statements. In the future, these definitions should also be considered for guidelines and treatment trials in cardiovascular medicine. The current review aims to summarize important information and development in the fields of muscle wasting, sarcopenia and cachexia, focusing on findings in cardiovascular research, in order for cardiologists to have a better understanding of the progress in this still insufficiently known field.

Androgens and skeletal muscle: cellular and molecular action mechanisms underlying the anabolic actions

Androgens increase both the size and strength of skeletal muscle via diverse mechanisms. The aim of this review is to discuss the different cellular targets of androgens in skeletal muscle as well as the respective androgen actions in these cells leading to changes in proliferation, myogenic differentiation, and protein metabolism. Androgens bind and activate a specific nuclear receptor which will directly affect the transcription of target genes. These genes encode muscle-specific transcription factors, enzymes, structural proteins, as well as microRNAs. In addition, anabolic action of androgens is partly established through crosstalk with other signaling molecules such as Akt, myostatin, IGF-I, and Notch. Finally, androgens may also exert non-genomic effects in muscle by increasing Ca(2+) uptake and modulating kinase activities. In conclusion, the anabolic effect of androgens on skeletal muscle is not only explained by activation of the myocyte androgen receptor but is also the combined result of many genomic and non-genomic actions.