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It was reported that Dipsaci radix (DR) has a reinforcement effect on the bone-muscle dysfunction in the oriental medical classics and the experimental animal studies. The muscle atrophy was induced by unilateral transection of the sciatic nerve of the rats. Water-extract of DR was used as treatment once a day for 12 days. The muscle weights of the hind limb, atrophic changes, glycogen contents, compositions and cross-section areas of muscle fiber types in soleus and medial gastrocnemius were investigated. Muscle fiber type was classified to type-I and type-II with MHCf immunohistochemistry. Furthermore, Bax and Bcl-2 expressions were observed with immunohistochemiatry. DR treatment significantly increased muscle weights of soleus, medial gastrocnemius, lateral gastrocnemius, and posterior tibialis of the damaged hind limb. DR treatment reduced apoptotic muscle nuclei and hyaline-degenerated muscle fibers in soleus and medial gastrocnemius of the damaged hind limb. DR treatment also significantly increased glycogen contents in medial gastrocnemius of the damaged hind limb. DR treatment significantly attenuated the slow-to-fast shift in soleus of the damaged hind limb but not in medial gastrocnemius. DR treatment significantly increased cross-section areas of type-I and type-II fibers in soleus and medial gastrocnemius of the damaged hind limb. In soleus and medial gastrocnemius, DR treatment significantly reduced Bax positive muscle nuclei in the damaged hind limb. These results suggest that DR treatment has an anti-atrophic effect and an anti-apoptotic effect against myonuclear apoptosis induced by the peripheral nerve damage.

The loss of skeletal muscle mass and function is a serious consequence of chronic diseases and aging. BST204 is a purified ginseng (the root of Panax ginseng) extract that has been processed using ginsenoside-$\beta$-glucosidase and acid hydrolysis to enrich ginsenosides Rg3 and Rh2 from the crude ginseng. BST204 has a broad range of health benefits, but its effects and mechanism on muscle atrophy are currently unknown. In this study, we have examined the effects and underlying mechanisms of BST204 on myotube formation and myotube atrophy induced by tumor necrosis factor-$\alpha$ (TNF-$\alpha$). BST204 promotes myogenic differentiation and multinucleated myotube formation through Akt activation. BST204 prevents myotube atrophy induced by TNF-$\alpha$ through the activation of Akt/mTOR signaling and down-regulation of muscle-specific ubiquitin ligases, MuRF1, and Atrogin-1. Furthermore, BST204 treatment in atrophic myotubes suppresses mitochondrial reactive oxygen species (ROS) production and regulates mitochondrial transcription factors such as NRF1 and Tfam, through enhancing the activity and expression of peroxisome proliferator-activated receptor-$\gamma$ coactivator1$\alpha$ (PGC1$\alpha$). Collectively, our findings indicate that BST204 improves myotube formation and PGC1$\alpha$-mediated mitochondrial function, suggesting that BST204 is a potential therapeutic or neutraceutical remedy to intervene muscle weakness and atrophy.

Muscle atrophy, or loss of skeletal muscle, is caused by aging, malnutrition, immobility through injury, or diseases such as cancer. Chamomile (Matricaria chamomilla L.) contains various active components, including flavonoids, sesquiterpenes, polyacetylenes, and coumarins, and is used in various herbal medicines in the European Pharmacopoeia. In this study, we investigated the effects of ethanol extract of chamomile (MC) on muscle wasting and its mechanism of action. Mice with dexamethasone (DEX)-induced muscle atrophy were orally administered MC (100, 200, and 300 mg/kg) for 4 weeks. Micro-computed tomography analysis showed that MC (200 and 300 mg/kg) significantly recovered DEX-induced loss of muscle volume, density, and weight and MC-treated DEX-induced mice also showed increased moving distance and grip strength. MC suppressed the mRNA level of muscle RING finger 1 (MuRF1) while increasing the expression of mitochondrial transcription factor A (TFAM), MyoD, and Myogenin-1. We found 25 peaks in MC samples through HPLC analysis and identified 6 peaks by comparison with a profile of standard compounds: chlorogenic acid (CGA), luteolin-7-O-glucoside (L7G), patulitrin, apigenin-7-O-glucoside (A7G), herniarin, and (E)-tonghaosu. Of these components, the gene expression of MyoD was significantly augmented by patulitrin, herniarin, CGA, and L7G in C2C12 cells, while Myogenin-1 gene expression was increased by A7G, patulitrin, herniarin, CGA, and L7G. Moreover, TFAM gene expression and phosphorylation of AKT were increased by all six ingredients. Based on our results, we suggest MC for use as a supplement or remedy for muscle wasting, including cachexia and sarcopenia.

Background: Knee traumata are associated with arthrogenic muscle inhibition (AMI). We aimed to identify impact factors on AMI. Methods: A total of 37 patients with meniscus injuries were interviewed and examined for maximum isometric knee extensor force preoperatively. We analyzed AMI as relative maximum isometric force between healthy and injured legs. Regression analyses were computed to evaluate associations between an AMI with muscle-strength reduction $>25$% and several parameters and between cartilage damage$>$stadium 3 and several parameters. ROC curves were calculated to investigate effectiveness of age and pain at rest for prediction of cartilage lesions $>$stadium 3. Results: Meniscus injuries lead to distinct AMI with reduced strength of 26.6% in mean. In multi-variate logistic regressions, an AMI with muscle weakness $>25$% was associated with higher severity of cartilage lesions (OR3.267, 95% CI 1.059–10.078, $p=0.0394$). In uni-variate regression analyses, pain at rest (OR1.398, 95%CI 1.071–1.824, $p=0.0137$) and patients’ age (per year) (OR1.145, 95%CI 1.042–1.257, $p=0.00488$) were associated with cartilage damage$>$stadium 3. Optimal cut-off values for patients’ age and pain at rest to predict cartilage damage stadium$>3$ were 44.5 years and VAS-scale-value 4.5 with good effectiveness (AUC 0.855 and 0.732), respectively. Conclusions: Meniscus injuries lead to distinct AMI with 26.6% reduction in muscle strength. Concomitant cartilage damage is an important cofactor for development of distinct AMI. Moderate to severe pain at rest and age $>44.5$ years were indicators for concomitant higher cartilage damage in patients with meniscal lesions.

Singapore Researchers Discover the Obesity Protein.

Treatment for Muscle Atrophy with Myostatin Protein.

No matter what the reason and level of amputation are, amputees will face many complex postoperative problems and potential complications. From the perioperative stage to lengthy rehabilitation process, patients need comprehensive and cautious therapies to help them rebuild their physical and mental health. Although there is some scattered information, the achievements of hemodynamic study for lower limb amputation and rehabilitation have not been systematically classified and summarized. The purpose of this review is to introduce and discuss the hemodynamic issues in preoperative diagnosis, surgical techniques and postoperative problems in the past two decades. Whether from clinical or biomechanical perspective, the investigations of the former two stages have been relatively mature and gained some clear outcomes, even if some conclusions are conflicting and controversial. While in terms of the postoperative problems, such as the common pressure ulcers, DTI and muscle atrophy, there is a lack of vascular or blood flow state studies specifically for lower residual limb. Therefore, the future research focus of hemodynamics for lower limb amputation should probably be the detailed investigations on the relationships between various blood flow parameters and certain common complications. Although hemodynamic research has made some achievements at this stage, it is believed that more advanced and reliable techniques are pending for further explorations and developments.

A novel healthy state monitor method of upper limb for space flight task is proposed. Without taking other complex diagnosis equipment in orbit, this method only uses the ordinary exercise instruments to collect and analyze the multiple muscle forces of astronauts, and deduces where the serious muscle atrophy occurs in their muscle groups of upper limb. First, the typical multiple muscle forces data of upper limb are accumulated. A 45-day 6-degree head-down tilt bed rest experiment together with a multiple muscle forces test experiment are carried out to collect the corresponding data. These data include both the muscle force data of healthy state and the related data of unhealthy state. Second, the Wavelet Packet Transform (WPT) and the Empirical Mode Decomposition (EMD) methods are used to compute the signal features of these data above. Third, a Support Vector Machine (SVM) classifier is trained by the related signal features. Finally, the trained SVM can be utilized to evaluate the healthy state of upper limb in orbit for astronaut. If the output of SVM is negative, the C-means method and the Euclidean distance can be used to locate the abnormal muscle forces and muscle groups. The concept of typical muscle group health state evaluation for upper limb is emphasized in this paper. The comparisons among the traditional diagnosis-based method, the electromyogram (EMG)-based muscle forces analysis method, and the proposed method are made. Many experiment results on ground have verified the effectiveness of proposed method.

Objective: To investigate the effects of extremely low-frequency electromagnetic fields (ELF-EMF) on myogenesis during the early stage of denervated muscle atrophy in Sprague-Dawley (SD) rats. Methods: a total of 36 female SD rats were fed in cages and divided into three groups: the normal control group, the muscle atrophy group and the 10Hz/1.5mT magnetic field group. The rats in the 10Hz/1.5mT magnetic field group received a magnetic field intervention for 2h per day. The posterior muscle groups of the lower limbs of rats were sampled on the first, second, third and fourth weeks for evaluating the underlying changes. The harvested tissues were stained with hematoxylin–eosin (HE) dye to observe the morphology of the muscle atrophy and to measure the muscle fiber cross-sectional area ratio. A reverse transcription polymerase chain reaction was used to detect the expression of Myf5 mRNA in each group. The myogenesis-related proteins in the harvested muscle tissue were detected by western blot assay. Results: (1) HE staining showed that with the extension of denervation time, the structural disorder of muscle fibers was aggravated, and in the second week of the denervated muscle atrophy, muscle fiber cross-sectional area tended to increase in the 10Hz/1.5mT magnetic field group. Overall muscle atrophy was inevitable. (2) Results of RT-PCR showed that the expression of Myf5 mRNA in the 10Hz/1.5mT magnetic field group was significantly high in the second week of denervation, and the difference was statistically significant compared with the muscle atrophy group (*$p<0.05$). (3) Western blot analysis showed that the expression of MYF5 proteins in the 10Hz/1.5mT magnetic field group was significantly higher than that in the muscle atrophy group (**$p<0.01$) in the second week of denervation. Further, the expression of MYOG protein in the 10Hz/1.5mT magnetic field group was significantly higher than that in the muscle atrophy group (****$p<0.0001$). Conclusions: 10Hz/1.5mT ELF-EMF can significantly promote myogenesis during early denervated muscle atrophy in SD rats.

Musculoskeletal diseases, especially osteoporosis, are serious health threats to many individuals including the aging elderly, astronauts, and long-duration-functional-resting (e.g. spinal cord injury) patients. The degree of bone loss and muscle atrophy due to disuse is closely associated with increased fracture risk, affecting the morbidity and mortality of the population. Many appropriate animal models have been developed to fully investigate the mechanisms responsible for musculoskeletal adaptations under disuse environment; more importantly, these models are the key in discovering new interventions for osteoporosis. Hindlimb suspension (HLS) is a well-accepted functional disuse model employed on rodents. In this model, the animal's hindlimbs are lifted and suspended for a period of time (days to weeks), thus removing daily weight-bearing activities to the hindlimbs. This chapter will mainly focus on the technical aspects of HLS as a functional disuse model for studying musculoskeletal tissues. Detailed materials and methods are provided for investigators to easily design and efficiently set up a HLS study. The limitations of HLS and other alternative functional disuse models (i.e. casting and neurectomy) are also discussed for further consideration.