Morin improves dexamethasone-induced muscle atrophy by modulating atrophy-related genes and oxidative stress in female mice.

This study investigated the effect of morin, a flavonoid, on dexamethasone-induced muscle atrophy in C57BL/6J female mice. Dexamethasone (10 mg/kg body weight) for 10 days significantly reduced body weight, gastrocnemius and tibialis anterior muscle mass, and muscle protein in mice. Dexamethasone significantly upregulated muscle atrophy-associated ubiquitin ligases, including atrogin-1 and MuRF-1, and the upstream transcription factors FoxO3a and Klf15. Additionally, dexamethasone significantly induced the expression of oxidative stress-sensitive ubiquitin ligase Cbl-b and the accumulation of the oxidative stress markers malondialdehyde and advanced protein oxidation products in both the plasma and skeletal muscle samples. Intriguingly, morin treatment (20 mg/kg body weight) for 17 days effectively attenuated the loss of muscle mass and muscle protein and suppressed the expression of ubiquitin ligases while reducing the expression of upstream transcriptional factors. Therefore, morin might act as a potential therapeutic agent to attenuate muscle atrophy by modulating atrophy-inducing genes and preventing oxidative stress.

The extract of Ilex kudingcha inhibits atherosclerosis in apoE-deficient mice by suppressing cholesterol accumulation in macrophages.

It was previously reported that oleanolic acid and ursolic acid, triterpenoid compounds occurring in Ilex kudingcha, ameliorate hyperlipidemia and atherosclerosis in apoE-deficient mice. In the present study, we investigated whether I. kudingcha extract exerts similar inhibitory effects on cholesterol accumulation in human monocyte-derived macrophages (HMDMs) and atherogenesis in apoE-deficient mice. I. kudingcha extract significantly inhibited cholesterol ester (CE) accumulation induced by acetylated LDL (acetyl-LDL) in HMDMs; however, it generated no effect on cell viability in HMDMs. I. kudingcha extract also suppressed CE accumulation in acyl-CoA:cholesterol acyl-transferase (ACAT)-overexpressing Chinese hamster ovary (CHO) cells, thereby indicating that it inhibits ACAT activity. Furthermore, the oral administration of I. kudingcha extract to apoE-deficient mice significantly decreased the levels of serum cholesterol, triglyceride, sLOX-1, as well as the regions of atherosclerotic lesions in the mice. Our study reveals crucial new-found evidence that I. kudingcha extract significantly inhibits ACAT activity and suppresses atherogenesis.

The effect of eleutherococcus senticosus on metabolism-associated protein expression in 3T3-L1 and C2C12 cells.

PURPOSE: In vivo studies have demonstrated the ergogenic benefits of eleutherococcus senticosus (ES) supplementation. ES has been observed to enhance endurance capacity, improve cardiovascular function, and alter metabolic functions (e.g., increased fat utilization); however, the exact mechanisms involved remain unknown. We aimed to determine whether ES could effectively induce fat loss and improve muscle metabolic profiles through increases in lipolysis- and lipid metabolism-associated protein expression in 3T3-L1 adipocytes and C2C12 skeletal muscle cells, respectively, to uncover the direct effects of ES on adipocytes and skeletal muscle cells. METHODS: Different doses of ES extracts (0.2, 0.5, and 1.0 mg/mL) were added to cells (0.2 ES, 0.5 ES, and 1.0 ES, respectively) for 72 h and compared to the vehicle control (control). RESULTS: The intracellular triacylglycerol (TG) content significantly decreased (p < 0.05 for 0.2 ES, p < 0.01 for 0.5 ES and 1.0 ES) in 3T3-L1 cells. Adipose triglyceride lipase, which is involved in active lipolysis, was significantly higher in the 1.0 ES group than in the control group (p < 0.01) of 3T3-L1 adipocytes. In C2C12 cells, the mitochondrial protein voltage-dependent anion channel (VDAC) was significantly increased in the 1.0 ES group (p < 0.01). Furthermore, we found that 1.0 ES activated both 5' AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) in skeletal muscle cells (p < 0.01). CONCLUSION: These findings suggest that ES extracts decreased TG content, presumably by increasing lipase in adipocytes and metabolism-associated protein expression as well as mitochondrial biogenesis in muscle cells. These effects may corroborate previous in vivo findings regarding the ergogenic effects of ES supplementation.

Effect of oral γ-aminobutyric acid (GABA) administration on sleep and its absorption in humans.

The effects of γ-aminobutyric acid (GABA) on sleep and its levels in blood after oral administration were investigated in humans. A randomized, single-blind, placebo-controlled crossover-designed study was conducted to evaluate the effect of GABA on sleep. Sleep was evaluated by electroencephalography (EEG) after oral GABA administration. GABA significantly shortened sleep latency and increased the total non-rapid eye movement (non-REM) sleep time. Questionnaires showed that subjects receiving GABA realized its effects on sleep. In addition, the blood level of GABA after administration was investigated, and the absorption and metabolism rates of GABA were determined. GABA was quickly absorbed, and the blood level of GABA was the highest 30 min after oral administration, with a subsequent decrease in concentration. As GABA strongly affected the early stage of sleep, the effect of GABA on sleep may be connected to its levels in blood.

The Improvement of Sleep by Oral Intake of GABA and Apocynum venetum Leaf Extract.

The effects of two food materials, γ-aminobutyric acid (GABA) produced by natural fermentation and Apocynum venetum leaf extract (AVLE), on the improvement of sleep were investigated in humans. The electroencephalogram (EEG) test revealed that oral administration of GABA (100 mg) and AVLE (50 mg) had beneficial effects on sleep. GABA shortened sleep latency by 5.3 min and AVLE increased non-rapid eye movement (REM) sleep time by 7.6%. Simultaneous intake of GABA and AVLE shortened sleep latency by 4.3 min and increased non-REM sleep time by 5.1%. The result of questionnaires showed that GABA and AVLE enabled subjects to realize the effects on sleep. These results mean that GABA can help people to fall asleep quickly, AVLE induces deep sleep, and they function complementarily with simultaneous intake. Since both GABA and AVLE are materials of foods and have been ingested for a long time, they can be regarded as safe and appropriate for daily intake in order to improve the quality of sleep.

Why is sialic acid attracting interest now? Complete enzymatic synthesis of sialic acid with N-acylglucosamine 2-epimerase.

N-Acetylneuraminic acid (NeuAc), the representative of the family of sialic acids, is an important molecule in biological recognition systems. Currently, NeuAc-based novel pharmaceutical agents and diagnostic reagents for influenza viruses are highly required in medical fields, and larger amounts of NeuAc are in demand worldwide. NeuAc had been prepared either from colominic acid (a homopolymer of NeuAc) produced by fermentation or from natural sources such as edible bird's nests, milk or eggs. However, the drawbacks of such conventional methods make them unsuitable for large-scale production of NeuAc. Recently, the N-acylglucosamine 2-epimerase (AGE) gene from porcine kidney was cloned in E. coli, and a strain with a high AGE expression level was constructed for practical applications, which enabled the complete enzymatic synthesis of NeuAc with a high conversion rate from the substrates, namely, N-acetylglucosamine and pyruvate. In addition, NeuAc of highest purity could be produced economically via its direct crystallization from the reaction mixture without any column purification processes. Such a simple procedure promises to be applicable to the mass production of sialic acid at the lowest cost.