γ-Oryzanol Improves Exercise Endurance and Muscle Strength by Upregulating PPARδ and ERRγ Activity in Aged Mice.

SCOPE: γ-Oryzanol, a well-known antioxidant, has been used by body builders and athletes to boost strength and increase muscle gain, without major side effects. However, the effect of γ-Oryzanol on sarcopenia and the underlying molecular mechanism is poorly understood. RESULTS: Aged mice fed with the γ-Oryzanol diet do not show significant changes in muscle weight, but show increased running endurance as well as improved grip strength. The expression and activity of PPARδ and ERRγ are increased in skeletal muscle of γ-Oryzanol supplemented mice. γ-Oryzanol upregulates oxidative muscle fibers by MEF2 transcription factor, and PGC-1α and ERRα expressions. Fatty acid oxidation related genes and mitochondria biogenesis are upregulated by γ-Oryzanol. In addition, γ-Oryzanol inhibits TGF-ß-Smad-NADPH oxidase 4 pathway and inflammatory cytokines such as TNF-α, IL-1ß, IL-6, and p65 NF-κB subunit, which cause skeletal muscle weakness. Collectively, γ-Oryzanol attenuates muscle weakness pathway and increases oxidative capacity by increasing PPARδ and ERRγ activity, which contributes to enhance strength and improve oxidative capacity in muscles, consequently enhancing exercise capacity in aged mice. Particularly, γ-Oryzanol directly binds to PPARδ. CONCLUSIONS: These are the first findings showing that γ-Oryzanol enhances skeletal muscle function in aged mice by regulating PPARδ and ERRγ activity without muscle gain.

Pharmacoepidemiology and clinical characteristics of medication-related osteonecrosis of the jaw.

BACKGROUND: The aim of this study was to investigate clinical and pharmacoepidemiologic characteristics of medication-related osteonecrosis of the jaw. METHODS: The study population is comprised of 86patients who were diagnosed with ONJ at Ewha Womans University Mokdong Hospital from 2008 to 2015. Factors for epidemiologic evaluation were gender, age, location of lesion, and clinical history. The types of bisphosphonates, duration of intake, and the amount of accumulated dose were evaluated for therapeutic response. Clinical symptoms and radiographic images were utilized for the assessment of prognosis. RESULTS: Among the 86 patients, five were male, whereas 81 were female with mean age of 73.98 (range 45-97). Location of the lesion was in the mandible for 58 patients and maxilla in 25 patients. Three patients had both mandible and maxilla affected. This shows that the mandible is more prone to the formation of ONJ lesions compared to the maxilla. ONJ occurred in 38 cases after extraction, nine cases after implant surgery, six cases were denture use, and spontaneously in 33 cases. Seventy-six patients were taking other drugs aside from drugs indicated for osteoporosis. Most of these patients were diagnosed as osteoporosis, rheumatic arthritis, multiple myeloma, or had a history of cancer therapy. Higher weighted total accumulation doses were significantly associated with poorer prognosis (P < 0.05). CONCLUSION: Dose, duration, route, and relative potency of bisphosphonates are significantly associated with treatment prognosis of osteonecrosis of the jaw.

Hydrangea serrata Tea Enhances Running Endurance and Skeletal Muscle Mass.

SCOPE: Skeletal muscle mass and quality can be negatively affected by aging, inactivity, and disease, while a loss of muscle mass is associated with chronic disease status, falls, and mortality. We investigate the effects of Hydrangea serrata on skeletal muscle mass and function, along with the underlying mechanisms. METHODS AND RESULTS: H. serrata, identified through MyoD transcription activity screening, increases myogenic differentiation via Akt and p38. C57BL/6 mice are fed a 0.25% or 0.5% H. serrata diet for 8 weeks. H. serrata increased treadmill running distance and maximum speed, as well as skeletal muscle mass. H. serrata promotes the expression of myosin heavy chain 1 (MHC1) and MHC2A but not MHC2B. H. serrata also upregulates the protein expression of peroxisome proliferator-activated receptor δ (PPARδ) and mitochondrial complexes, and enhances citrate synthase and mitochondrial complex І activity. Transforming growth factor-ß (TGF-ß), myostatin, and growth differentiation factor 11 (GDF11) are attenuated by H. serrata, together with associated downstream signaling factors including phospho-Smad3 and NADPH oxidase 4 (NOX4). CONCLUSION: H. serrata enhances exercise endurance by upregulating PPARδ and downregulating TGF-ß, myostatin, and GDF11. H. serrata is a potential candidate for the development of functional food to maintain skeletal muscle mass and function.

2,6-Dimethoxy-1,4-benzoquinone Inhibits 3T3-L1 Adipocyte Differentiation via Regulation of AMPK and mTORC1.

2,6-Dimethoxy-1,4-benzoquinone is a natural phytochemical present in fermented wheat germ. It has been reported to exhibit anti-inflammatory, antitumor, and antibacterial activities. However, the anti-adipogenic effects of 2,6-dimethoxy-1,4-benzoquinone and the mechanisms responsible have not previously been elucidated. Such findings may have ramifications for the treatment of obesity. 2,6-Dimethoxy-1,4-benzoquinone (5 and 7.5 µM) significantly reduced the expression of various adipogenic transcription factors, including peroxisome proliferator-activated receptor-γ and CCAAT/enhancer binding protein α as well as adipocyte protein 2 and fatty acid synthase. 2,6-Dimethoxy-1,4-benzoquinone upregulated AMP-dependent protein kinase phosphorylation and inhibited the mature form of sterol regulatory element-binding protein 1c. Notably, 2,6-dimethoxy-1,4-benzoquinone attenuated mammalian target of rapamycin complex 1 activity in 3T3-L1 and mouse embryonic fibroblast cells. These findings highlight a potential role for 2,6-dimethoxy-1,4-benzoquinone in the suppression of adipogenesis. Further studies to determine the anti-obesity effects of 2,6-dimethoxy-1,4-benzoquinone in animal models appear warranted.

Apigenin inhibits sciatic nerve denervation-induced muscle atrophy.

INTRODUCTION: Apigenin (AP) has been reported to elicit anti-inflammatory effects. In this study, we investigated the effect of AP on sciatic nerve denervation-induced muscle atrophy. METHODS: Sciatic nerve-denervated mice were fed a 0.1% AP-containing diet for 2 weeks. Muscle weight and cross-sectional area (CSA), and the expression of atrophic genes and inflammatory cytokines in the gastrocnemius were analyzed. RESULTS: Denervation significantly induced muscle atrophy. However, values for muscle weight and CSA were greater in the denervated muscle of the AP mice than the controls. AP suppressed the expression of MuRF1, but upregulated both myosin heavy chain (MHC) and MHC type IIb. AP also significantly suppressed expression of tumor necrosis-alpha in the gastrocnemius and soleus muscles, and interleukin-6 expression in the soleus muscle. DISCUSSION: AP appears to inhibit denervation-induced muscle atrophy, which may be due in part to its inhibitory effect on inflammatory processes within muscle. Muscle Nerve 58: 314-318, 2018.

Coffee consumption promotes skeletal muscle hypertrophy and myoblast differentiation.

Coffee is a widely consumed beverage worldwide and is believed to help prevent the occurrence of various chronic diseases. However, the effect of coffee on skeletal muscle hypertrophy, differentiation and the mechanisms of action responsible have remained unclear. To investigate the effect of coffee on skeletal muscle hypertrophy, mice were fed a normal diet or a normal diet supplemented with 0.3% coffee or 1% coffee. Coffee supplementation was observed to increase skeletal muscle hypertrophy, while simultaneously upregulating protein expression of total MHC, MHC2A, and MHC2B in quadricep muscle. Myostatin expression was also attenuated, and IGF1 was upregulated with subsequent phosphorylation of Akt and mTOR, while AMPK phosphorylation was attenuated. Coffee also increased the grip strength and PGC-1α protein expression, and decreased the expressions of TGF-ß and myostatin in tricep muscle. Coffee activated the MKK3/6-p38 pathway and upregulated PGC-1α, which may play a role in promoting myogenic differentiation and myogenin expression in C2C12 cells. These results suggest that coffee increases skeletal muscle function and hypertrophy by regulating the TGF-ß/myostatin - Akt - mTORC1.

Coumestrol modulates Akt and Wnt/ß-catenin signaling during the attenuation of adipogenesis.

Coumestrol is a natural phytochemical present in plants such as red clover and soy, and has been reported to stimulate the estrogen receptor as a major phytoestrogen. While the molecular mechanisms responsible for the anti-adipogenic effects of phytoestrogens such as genistein and daidzein have been previously investigated, the effects of coumestrol on adipogenesis remain to be elucidated. We observed that coumestrol dose-dependently attenuates MDI (mixture of 3-isobutyl-1-methylxanthine, dexamethasone, and insulin)-induced lipid accumulation, consistent with an earlier study, while significantly inhibiting MDI-induced adipogenesis in the first 48 hours of differentiation, a critical time window for anti-adipogenic effects. Coumestrol treatment suppressed MDI-induced protein expression of PPARγ and C/EBPα in adipocytes, leading to the subsequent downregulation of FAS and aP2 expression. Akt and GSK3ß were phosphorylated shortly after MDI stimulation, and these responses were inhibited by coumestrol treatment. Coumestrol also increased LRP6 protein expression, resulting in the recovery of ß-catenin downregulation by MDI, while attenuating MDI-induced downregulation of Wnt10b. In addition, mRNA and protein expression of c-Myc and cyclin D1, target genes of ß-catenin, were both recovered by coumestrol treatment. These results suggest that coumestrol inhibits adipocyte differentiation via regulation of Akt and Wnt/ß-catenin signaling and may have potential for development as an agent to prevent adipogenesis.

Roles of cysteine residues in the inhibition of human glutamate dehydrogenase by palmitoyl-CoA.

Human glutamate dehydrogenase isozymes (hGDH1 and hGDH2) have been known to be inhibited by palmitoyl-CoA with a high affinity. In this study, we have performed the cassette mutagenesis at six different Cys residues (Cys59, Cys93, Cys119, Cys201, Cys274, and Cys323) to identify palmitoyl- CoA binding sites within hGDH2. Four cysteine residues at positions of C59, C93, C201, or C274 may be involved, at least in part, in the inhibition of hGDH2 by palmitoyl-CoA. There was a biphasic relationship, depending on the levels of palmitoyl-CoA, between the binding of palmitoyl-CoA and the loss of enzyme activity during the inactivation process. The inhibition of hGDH2 by palmitoyl-CoA was not affected by the allosteric inhibitor GTP. Multiple mutagenesis studies on the hGDH2 are in progress to identify the amino acid residues fully responsible for the inhibition by palmitoyl-CoA.