Combination of tea catechins and ornithine effectively activates the urea cycle: an in vitro and human pilot study

PURPOSE

Accumulation of ammonia causes central and peripheral fatigue. This study aimed to investigate the synergistic effect of tea catechins and low-dose ornithine in activating the urea cycle to reduce blood ammonia levels during exercise.

METHODS

We used hepatocyte-like cells derived from human-induced pluripotent stem (iPS) cells to assess the effect of tea catechins combined with ornithine on urea cycle activity. The urea production and expression of key genes involved in the metabolism of urea were investigated. We then examined the synergistic improvement in ammonia metabolism by tea catechins in combination with ornithine in a human pilot study.

RESULTS

Tea catechins combined with ornithine increased urea cycle activity in hepatocyte-like cells derived from human iPS cells. Intake of 538.6 mg of tea catechins with 1592 mg of ornithine for 2 consecutive days during exercise loading suppressed the exercise-induced increase in the blood ammonia concentration as well as stabilized blood glucose levels.

CONCLUSION

Controlling the levels of ammonia, a toxic waste produced in the body, is important in a variety of situations, including exercise. The present study suggests that a heterogeneous combination of polyphenols and amino acids efficiently suppresses elevated ammonia during exercise in humans by a mechanism that includes urea cycle activation.

TRIAL REGISTRATION

This study was registered in the University Hospital Medical Information Network Clinical Trial Registry (No. UMIN000035484, dated January 8, 2019).

Tyrosine Is a Booster of Leucine-Induced Muscle Anabolic Response

Leucine (Leu), an essential amino acid, is known to stimulate protein synthesis in the skeletal muscle via mTOR complex 1 (mTORC1) activation. However, the intrinsic contribution of other amino acids to Leu-mediated activation of mTORC1 signaling remains unexplored. This study aimed to identify amino acids that can promote mTORC1 activity in combination with Leu and to assess the effectiveness of these combinations in vitro and in vivo. We found that tyrosine (Tyr) enhanced Leu-induced phosphorylation of S6 kinase (S6K), an indicator of mTORC1 activity, although it exerted no such effect individually. This booster effect was observed in C2C12 cells, isolated murine muscle, and the skeletal muscles of mice orally administered the amino acids. To explore the molecular mechanisms underlying this Tyr-mediated booster effect, the expression of the intracellular Leu sensors, Sestrin1 and 2, was suppressed, and the cells were treated with Leu and Tyr. This suppression enabled Tyr alone to induce S6K phosphorylation and enhanced the booster effect, suggesting that Tyr possibly contributes to mTORC1 activation when Sestrin-GAP activity toward Rags 2 (GATOR2) is dissociated through Sestrin knockdown or the binding of Sestrins to Leu. Collectively, these results indicate that Tyr is a key regulator of Leu-mediated protein synthesis.

Antiviral Effect of Propylene Glycol against Envelope Viruses in Spray and Volatilized Forms

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly contagious and continues to spread worldwide. To avoid the spread of infection, it is important to control its transmission routes. However, as methods to prevent airborne infections are lacking, people are forced to take measures such as keeping distance from others or wearing masks. Here, we evaluate the antiviral activity of propylene glycol (PG), which is safe, odorless, and volatile. PG showed pronounced antiviral activity against the influenza virus (IAV) at concentrations above 55% in the liquid phase. Given its IAV inactivation mechanism, which involves increasing the fluidity of the viral membrane, PG is expected to have a broad effect on enveloped viruses. PG showed antiviral activity against SARS-CoV-2. We also developed a system to evaluate the antiviral effect of PG in spray and volatilized forms. PG was found to be effective against aerosol IAV in both forms; the effective PG concentration against IAV in the vapor phase was 87 ppmv (0.27 mg/L). These results demonstrate that PG is an effective means for viral inactivation in various situations for infection control. This technology is expected to control the spread of current and future infectious diseases capable of causing outbreaks and pandemics.

Non-invasive human skin transcriptome analysis using mRNA in skin surface lipids

Non-invasive acquisition of mRNA data from the skin can be extremely useful for understanding skin physiology and diseases. Inspired by the holocrine process, in which the sebaceous glands secrete cell contents into the sebum, we focused on the possible presence of mRNAs in skin surface lipids (SSLs). We found that measurable levels of human mRNAs exist in SSLs, where the sebum protects them from degradation by RNases. The AmpliSeq transcriptome analysis was modified to measure SSL-RNA levels, and our results revealed that the SSL-RNAs predominantly comprised mRNAs derived from sebaceous glands, the epidermis, and hair follicles. Analysis of SSL-RNAs non-invasively collected from patients with atopic dermatitis revealed increased expression of inflammation-related genes and decreased expression of terminal differentiation-related genes, consistent with the results of previous reports. Further, we found that lipid synthesis-related genes were downregulated in the sebaceous glands of patients with atopic dermatitis. These results indicate that the analysis of SSL-RNAs is a promising strategy to understand the pathophysiology of skin diseases.

Inoue et al develop a non-invasive method of analyzing human skin mRNA using RNA in skin surface lipids collected with oil-blotting films. The authors outline the validation of this methodology and describe an application to determine transcriptome in skin surface lipids in patients with atopic dermatitis versus healthy skin.

Non-invasive diagnostic tool for Parkinson's disease by sebum RNA profile with machine learning

Parkinson's disease (PD) is a progressive neurodegenerative disease presenting with motor and non-motor symptoms, including skin disorders (seborrheic dermatitis, bullous pemphigoid, and rosacea), skin pathological changes (decreased nerve endings and alpha-synuclein deposition), and metabolic changes of sebum. Recently, a transcriptome method using RNA in skin surface lipids (SSL-RNAs) which can be obtained non-invasively with an oil-blotting film was reported as a novel analytic method of sebum. Here we report transcriptome analyses using SSL-RNAs and the potential of these expression profiles with machine learning as diagnostic biomarkers for PD in double cohorts (PD [n = 15, 50], controls [n = 15, 50]). Differential expression analysis between the patients with PD and healthy controls identified more than 100 differentially expressed genes in the two cohorts. In each cohort, several genes related to oxidative phosphorylation were upregulated, and gene ontology analysis using differentially expressed genes revealed functional processes associated with PD. Furthermore, machine learning using the expression information obtained from the SSL-RNAs was able to efficiently discriminate patients with PD from healthy controls, with an area under the receiver operating characteristic curve of 0.806. This non-invasive gene expression profile of SSL-RNAs may contribute to early PD diagnosis based on the neurodegeneration background.

Non-invasive evaluation of subjective sensitive skin by transcriptomics using mRNA in skin surface lipids

Sensitive skin is a condition characterized by hypersensitivity to environmental stimuli, and its pathophysiology has not been fully elucidated. Questionnaires based on subjective symptoms, intervention tests, and measuring devices are used to diagnose sensitive skin; however, objective evaluation methods, including biomarkers, remain to be established. This study aimed to investigate the molecular profiles of self-reported sensitive skin, understand its pathophysiology and explore its biomarkers. Here, we analysed RNAs in skin surface lipids (SSL-RNAs), which can be obtained non-invasively by wiping the skin surface with an oil-blotting film, to compare the transcriptome profiles between questionnaire-based "sensitive" (n = 11) and "non-sensitive" (n = 10) skin participants. Exactly 417 differentially expressed genes in SSL-RNAs from individuals with sensitive skin were identified, of which C-C motif chemokine ligand 17 and interferon-γ pathways were elevated, while 50 olfactory receptor (OR) genes were downregulated. The expression of the detectable 101 OR genes was lower in individuals with sensitive skin compared to that in those with non-sensitive skin and was particularly associated with the subjective sensitivity among skin conditions. The receiver operating characteristic (ROC) curve demonstrated that the mean expression levels of OR genes in SSL-RNAs could discriminate subjective skin sensitivity with an area under the ROC curve of 0.836. SSL-RNA profiles suggest a mild inflammatory state in sensitive skin, and overall OR gene expression could be a potential indicator for sensitive skin.

The Impact of Milk Fat Globule Membrane with Exercise on Age-Related Degeneration of Neuromuscular Junctions

Morphological changes in neuromuscular junctions (NMJs), which are synapses formed between α-motor neurons and skeletal muscle fibers, are considered to be important in age-related motor dysfunction. We have previously shown that the intake of dietary milk fat globule membrane (MFGM) combined with exercise attenuates age-related NMJ alterations in the early phase of aging. However, it is unclear whether the effect of MFGM with exercise on age-related NMJ alterations persists into old age, and whether intervention from old age is still effective when age-related changes in NMJs have already occurred. In this study, 6- or 18-month-old mice were treated with a 1% MFGM diet and daily running wheel exercise until 23 or 24 months of age, respectively. MFGM treatment with exercise was effective in suppressing the progression of age-related NMJ alterations in old age, and even after age-related changes in NMJs had already occurred. Moreover, the effect of MFGM intake with exercise was not restricted to NMJs but extended to the structure and function of peripheral nerves. This study demonstrates that MFGM intake with exercise may be a novel approach for improving motor function in the elderly by suppressing age-related NMJ alterations.

The potential geographical distribution and phenology of Bemisia tabaci Middle East/Asia Minor 1, considering irrigation and glasshouse production

The Bemisia tabaci species complex is one of the most important pests of open field and protected cropping globally. Within this complex, one species (Middle East Asia Minor 1, B. tabaci MEAM1, formerly biotype B) has been especially problematic, invading widely and spreading a large variety of plant pathogens, and developing broad spectrum pesticide resistance. Here, we fit a CLIMEX model to the distribution records of B. tabaci MEAM1, using experimental observations to calibrate its temperature responses. In fitting the model, we consider the effects of irrigation and glasshouses in extending its potential range. The validated niche model estimates its potential distribution as being considerably broader than its present known distribution, especially in the Americas, Africa and Asia. The potential distribution of the fitted model encompasses the known distribution of B. tabaci sensu lato, highlighting the magnitude of the threat posed globally by this invasive pest species complex and the viruses it vectors to open field and protected agriculture.

Tape stripping method is useful for the quantification of antimicrobial peptides on the human skin surface including the stratum corneum

Antimicrobial peptides (AMPs) play an important role in innate immunity in human skin. It is known that AMPs mainly function in the stratum corneum. Therefore, AMP concentrations in the stratum corneum need to be precisely measured to clarify functional and physiological importance of AMPs in cutaneous defence. Tape stripping (TS) is a well-established method by which components in the stratum corneum can be collected. However, the usefulness of the TS method for measuring AMP concentration in human skin remains unclear. Therefore, we compared it with another popular method, skin rinsing, which had been established as a method for measuring AMP concentration in human skin. When investigated on healthy medial forearm using RNase 7, which is one of the typical AMPs, as an index, there was a significant positive correlation between RNase 7 concentrations measured by the TS method at adjacent forearm sites, demonstrating the reproducibility of the TS method. Next, a significant positive correlation was detected in RNase 7 concentrations measured using the TS and the skin rinsing method, indicating that the TS method is comparable to the skin rinsing method. Thus, we speculate that the TS method is useful for measuring AMP concentration in human skin.

Continuous Supplementation of Milk Fat Globule Membrane with Habitual Exercise from a Young Age Improves Motor Coordination and Skeletal Muscle Function in Aged Mice

Since the decline of physical performance gradually progresses with aging, continuous exercise with nutritional supplementation from a young age is a feasible and effective way to maintain a comfortable life until late old age. We examined the effects of continuous milk fat globule membrane (MFGM) supplementation combined with voluntary running exercise (VR) for prevention of aging-associated declines in physical performance in naturally aging mice. The MFGM with VR group showed a significantly attenuated age-related decline in motor coordination and suppression of the loss of muscle mass and strength. Compared with the control group, the MFGM with VR group showed significantly higher mRNA and protein expression for docking protein 7, which maintains neuromuscular junction (NMJ) integrity, in the quadriceps muscles. These results suggest that dietary MFGM and VR attenuate natural aging-related decline in motor coordination and muscle function by regulating NMJ integrity.

Dietary instructions focusing on meal-sequence and nutritional balance for prediabetes subjects: An exploratory, cluster-randomized, prospective, open-label, clinical trial

BACKGROUND

Although lifestyle modifications are known to be effective in type 2 diabetes (T2D) as well as in prediabetes, adherence to a healthy diet is difficult for some, and interventions of lifestyle modifications need to be revised occasionally. Meal sequence has been gaining attention as a part of a healthy diet among T2D individuals to improve glycemia and body weight. In addition, a dietary instruction program, SMART Washoku®, which can help individuals to consume a more nutritionally balanced diet, has been developed.

METHODS

The current exploratory trial was designed to examine the effects of dietary instructions focusing on meal sequence and nutritional balance in individuals with prediabetes in the Japanese national health check-up and guidance program. Participants were cluster-randomized into three groups: Group A, receiving a conventional health guidance program (n = 11); Group B, receiving health guidance with dietary instructions focusing on meal sequence (n = 18); and Group C, receiving health guidance with dietary instructions focusing on nutritional balance (n = 13). Participants received health guidance education and various measurements before and 6 months after the instructions.

RESULTS

Body weight in Group B was significantly reduced compared to that in Group A, with similar adherence, while the effects on glycemia were similar between the two Groups. Body weight reduction was greater in Group C compared to that in Group A, although adherence in Group C was significantly lower than that in Group A.

CONCLUSION

The group receiving health guidance with dietary instructions focusing on meal sequence exhibited similar adherence and greater reduction in body weight than the group receiving conventional health guidance.

TRPM8-mediated cutaneous stimulation modulates motor neuron activity during treadmill stepping in mice

Motor units are generally recruited from the smallest to the largest following the size principle, while cutaneous stimulation has the potential to affect spinal motor control. We aimed to examine the effects of stimulating transient receptor potential channel sub-family M8 (TRPM8) combined with exercise on the modulation of spinal motor neuron (MN) excitability. Mice were topically administrated 1.5% icilin on the hindlimbs, followed by treadmill stepping. Spinal cord sections were immunostained with antibodies against c-fos and choline acetyltransferase. Icilin stimulation did not change the number of c-fos+ MNs, but increased the average soma size of the c-fos+ MNs during low-speed treadmill stepping. Furthermore, icilin stimulation combined with stepping increased c-fos+ cholinergic interneurons near the central canal, which are thought to modulate MN excitability. These findings suggest that TRPM8-mediated cutaneous stimulation with low-load exercise promotes preferential recruitment of large MNs and is potentially useful as a new training method for rehabilitation.

Coffee polyphenols prevent cognitive dysfunction and suppress amyloid β plaques in APP/PS2 transgenic mouse

Epidemiological studies have found that habitual coffee consumption may reduce the risk of Alzheimer's disease. Coffee contains numerous phenolic compounds (coffee polyphenols) such as chlorogenic acids. However, evidence demonstrating the contribution of chlorogenic acids to the prevention of cognitive dysfunction induced by Alzheimer's disease is limited. The present study investigated the effect of chlorogenic acids on the prevention of cognitive dysfunction in APP/PS2 transgenic mouse model of Alzheimer's disease. Five-week-old APP/PS2 mice were administered a diet supplemented with coffee polyphenols daily for 5 months. The memory and cognitive function of mice was determined using the novel object recognition test, Morris water maze test, and the step-through passive avoidance test. Immunohistochemical analysis revealed that chronic treatment with coffee polyphenols prevented cognitive dysfunction and significantly reduced the amount of amyloid β (Aβ) plaques in the hippocampus. Furthermore, we determined that 5-caffeoylquinic acid, one of the primary coffee polyphenols, did not inhibit Aβ fibrillation; however, degraded Aβ fibrils. In conclusion, our results demonstrate that coffee polyphenols prevent cognitive deficits and reduce Aβ plaque deposition via disaggregation of Aβ in the APP/PS2 mouse.

Precision Analysis of the ^{136}Xe Two-Neutrino ββ Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements

We present a precision analysis of the ^{136}Xe two-neutrino ββ electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino ββ rate allows us to measure the ratio of the leading and subleading 2νββ nuclear matrix elements (NMEs), ξ_{31}^{2ν}=-0.26_{-0.25}^{+0.31}. Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the ξ_{31}^{2ν} range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted ξ_{31}^{2ν} values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Because these aspects are also at play in neutrinoless ββ decay, ξ_{31}^{2ν} provides new insights toward reliable neutrinoless ββ NMEs.

Combined Supplementation of Pre-Exercise Carbohydrate, Alanine, and Proline and Continuous Intake of Green Tea Catechins Effectively Boost Endurance Performance in Mice

Continuous intake of green tea catechins (GTC) increases fatty acid utilization as an energy source and improves endurance capacity. Conversely, the single pre-exercise intake of maltodextrin (MD) as a carbohydrate source and the gluconeogenic amino acids alanine (Ala) and proline (Pro) effectively maintain blood glucose levels and increase endurance performance. In this study, we investigated the synergistic combinational effect of these interventions on endurance performance in mice. Male BALB/c mice were fed a 0.5% GTC diet or Control diet for 8 weeks. Maximum running time was measured every 2 weeks. MD (2 g/kg body weight (B.W.)), MD (1 g/kg B.W.) + AlaPro (9:1, 1 g/kg B.W.), and vehicle were orally administrated 60 mins before measurements in each diet group. The GTC + MD + AlaPro group showed significantly higher endurance performance than the Control-Vehicle group at all measurements. Indirect calorimetry analysis during running exercise at 4 weeks in the Control and GTC groups supplemented with pre-exercise MD + AlaPro administration revealed significantly higher fat oxidation in the GTC groups compared to the Control group. The combined increase in fatty acid utilization through continuous GTC intake and pre-exercise MD + AlaPro carbohydrate energy supplementation synergistically improves endurance capacity.

Guava leaf extract suppresses osteoarthritis progression in a rat anterior cruciate ligament transection model

Guava leaf extract and ellagic acid, one of its polyphenolic components, inhibit the activity of a disintegrin and metalloproteinase with thrombospondin type 5 (ADAMTS-5), which is associated with aggrecan degeneration during the early stage of osteoarthritis (OA). To investigate the efficacy of guava leaf extract for preventing OA, we examined the effect of its dietary intake on cartilage destruction in anterior cruciate ligament-transected (ACLT) rats. Rats were randomly assigned to four groups: ACLT control rats fed with control diet, ACLT rats fed with diet containing 0.2% guava leaf extract, ACLT rats fed with diet containing 0.5% guava leaf extract, and sham-operated rats fed with control diet. Mankin's scores, an index of cartilage damage, were higher in rats that underwent ACLT. Guava leaf extract treatment dose-dependently led to lower Mankin's scores and higher concentrations of ellagic acid in the serum and synovial membrane. Ellagic acid levels in the synovial membrane negatively correlated with cartilage destruction scores. These results suggest that dietary guava leaf extract suppresses OA progression in ACLT rats through ellagic acid-mediated inhibition of early joint destruction.

Light rhythmic exercise with dietary milk fat globule membrane improves physical fitness in an elderly Japanese population: a double-blind randomized placebo-controlled trial

This study aimed to investigate the efficacy of home-based, light gymnastic exercise plus dietary milk fat globule membrane (MFGM) intake on physical fitness of an elderly Japanese sample in a pilot, double-blind, randomized, placebo-controlled trial. Seventy-one subjects (male, n = 13; female, n = 58) were randomly assigned into two groups: placebo (n = 35 [male, n = 6; female, n = 29]) and MFGM group (n = 36 [male, n = 7; female, n = 29]). The intervention was eight weeks. Subjects ingested either MFGM (1 g/day) or placebo tablets daily and engaged in an exercise program daily. Physical function tests were performed at baseline and after four and eight weeks. Foot tapping and open–close stepping scores significantly increased from baseline to eight weeks in the MFGM group. Study results suggest daily MFGM ingestion might further enhance the effects of light-intensity exercise in healthy elderly people.

Dietary steamed wheat bran increases postprandial fat oxidation in association with a reduced blood glucose-dependent insulinotropic polypeptide response in mice

Obesity is a global epidemic associated with a higher risk of cardiovascular disease and metabolic disorders, such as type 2 diabetes. Previous studies demonstrated that chronic feeding of steamed wheat bran (WB) decreases obesity. To clarify the underlying mechanism and the responsible component for the anti-obesity effects of steamed WB, we investigated the effects of dietary steamed WB and arabinoxylan on postprandial energy metabolism and blood variables. Overnight-fasted male C57BL/6J mice were fed an isocaloric diet with or without steamed WB (30%). Energy metabolism was evaluated using an indirect calorimeter, and plasma glucose, insulin, and glucose-dependent insulinotropic polypeptide (GIP) levels were measured for 120 min after feeding. We similarly investigated the effect of arabinoxylan, a major component of steamed WB. Mice fed the WB diet had higher postprandial fat oxidation and a lower blood GIP response compared with mice fed the control diet. Mice fed the arabinoxylan diet exhibited a dose-dependent postprandial blood GIP response; increasing the arabinoxylan content in the diet led to a lower postprandial blood GIP response. The arabinoxylan-fed mice also had higher fat oxidation and energy expenditure compared with the control mice. In conclusion, the findings of the present study revealed that dietary steamed WB increases fat oxidation in mice. Increased fat oxidation may have a significant role in the anti-obesity effects of steamed WB. The postprandial effects of steamed WB are due to arabinoxylan, a major component of WB. The reduction of the postprandial blood GIP response may be responsible for the increase in postprandial fat utilization after feeding on a diet containing steamed WB and arabinoxylan.

Milk fat globule membrane supplementation with voluntary running exercise attenuates age-related motor dysfunction by suppressing neuromuscular junction abnormalities in mice

Age-related loss of skeletal muscle mass and function attenuates physical performance, and maintaining fine muscle innervation is known to play an important role in its prevention. We had previously shown that consumption of milk fat globule membrane (MFGM) with habitual exercise improves the muscle mass and motor function in humans and mice. Improvement of neuromuscular junction (NMJ) was suggested as one of the mechanisms underlying these effects. In this study, we evaluated the effect of MFGM intake combined with voluntary running (MFGM-VR) on morphological changes of NMJ and motor function in aging mice. Seven months following the intervention, the MFGM-VR group showed a significantly improved motor coordination in the rotarod test and muscle force in the grip strength test compared with the control group at 13 and 14months of age, respectively. In 14-month old control mice, the extensor digitorum longus muscle showed increased abnormal NMJs, such as fragmentation and denervation, compared with 6-month old young mice. However, such age-related deteriorations of NMJs were significantly suppressed in the MFGM-VR group. Increase in the expression of NMJ formation-related genes, such as agrin and LDL Receptor Related Protein 4 (LRP4), might contribute to this beneficial effect. Rotarod performance and grip strength showed significant negative correlation with the status of denervation and fragmentation of NMJs. These results suggest that MFGM intake with voluntary running exercise effectively suppresses age-related morphological deterioration of NMJ, thus contributing to improvement of motor function.

Reduction in hydroxyhydroquinone from coffee increases postprandial fat utilization in healthy humans: a randomized double-blind, cross-over trial

The present study aimed to clarify the effect of reduction in hydroxyhydroquinone (HHQ) from roasted coffee on energy utilization in humans. Indirect calorimetry showed that one-week ingestion of HHQ-reduced coffee led to significantly higher postprandial fat utilization than that of HHQ-containing coffee. This finding indicates that reduction in HHQ from coffee increases postprandial fat utilization.

Daily consumption of tea catechins improves aerobic capacity in healthy male adults: a randomized double-blind, placebo-controlled, crossover trial

Our previous studies demonstrated that dietary supplementation with tea catechins combined with exercise improved endurance capacity in mice. This study aimed to demonstrate the effect of daily tea catechin consumption on aerobic capacity in humans. Sixteen Japanese non-athlete male subjects (aged 25-47 years) took 500 mL of a test beverage with or without tea catechins (570 mg) daily for 8 weeks and attended a training program twice a week. Aerobic capacity was evaluated by indirect calorimetry and near-infrared spectroscopy during graded cycle exercise. Catechin beverage consumption was associated with a significantly higher ventilation threshold during exercise and a higher recovery rate of oxygenated hemoglobin and myoglobin levels after graded cycle exercise when compared to subjects receiving the placebo beverage. These results indicate that daily consumption of tea catechins increases aerobic capacity when combined with semiweekly light exercise, which may be due to increased skeletal muscle aerobic capacity.

Dietary milk fat globule membrane supplementation combined with regular exercise improves skeletal muscle strength in healthy adults: a randomized double-blind, placebo-controlled, crossover trial

Background

Our previous studies demonstrated that dietary supplementation with milk fat globule membrane (MFGM) combined with habitual exercise improved muscle strength by stimulating neuromuscular development in mice. This study aimed to demonstrate the beneficial effects of dietary MFGM supplementation plus regular exercise on muscle strength and neuromuscular function in healthy humans.

Methods

The study was designed as a randomized, double-blind, placebo-controlled, crossover trial. Fourteen Japanese adults aged 31–48 years took daily MFGM (1 g) or placebo tablets during the 4-week study period and attended a training program twice a week. Physical function tests and surface electromyography (EMG) were conducted at baseline and at the end of the study period.

Results

The MFGM group had significantly greater leg extension strength than the placebo group after the 4-week study period. Surface EMG showed that the MFGM group had a significantly higher root mean square amplitude than the placebo group, which indicated that the MFGM group had higher motor unit activity.

Conclusions

Dietary MFGM supplementation combined with regular exercise improves skeletal muscle strength, which may be due to increased motor unit recruitment in healthy Japanese middle-aged adults.

Daily consumption of milk fat globule membrane plus habitual exercise improves physical performance in healthy middle-aged adults

Our recent studies demonstrated that habitual exercise plus dietary supplementation with milk fat globule membrane (MFGM) improved endurance capacity and muscle function by stimulating neuromuscular development in mice. The aim of this study was to investigate the efficacy of dietary MFGM supplementation plus habitual exercise on the physical performance of middle-aged Japanese adults in a pilot randomized, double-blind, placebo-controlled trial. Forty-four subjects (men, n = 22; women, n = 22) were randomly assigned into two groups: one received placebo tablets (placebo group, n = 22 [men, n = 11; women, n = 11]), while the other received MFGM tablets (MFGM group, n = 22 [men, n = 11; women, n = 11]). The subjects ingested either MFGM (1 g/day) or placebo (1 g/day of whole milk powder) tablets every day for the 10-week study period and engaged in an exercise training program twice per week. A physical function test was performed at baseline and at 5 and 10 weeks. A significant group-by-time interaction was found for the side step test, muscle cross-sectional area (CSA), and muscle fiber conduction velocity (MFCV). In the placebo group, there were no significant intragroup differences. In the MFGM group, side step score and muscle CSA were significantly greater at 10 weeks compared to the baseline, and MFCV was significantly higher than that in the placebo group at 10 weeks. The changes in percentage of the side step score, muscle CSA, and MFCV in the MFGM group were significantly higher than in the placebo group at 10 weeks. These results suggest that daily MFGM ingestion combined with regular exercise might enhance physical performance such as agility in middle-aged adults.

Dendritic cell CD83 homotypic interactions regulate inflammation and promote mucosal homeostasis

Dendritic cells (DCs) form an extensive network in the intestinal lamina propria, which orchestrates the mucosal immune response. Alterations in DC function can predispose to inflammatory bowel disease, although by unknown mechanisms. We show that CD83, a highly regulated DC cell surface protein, modulates the immune response to prevent colitis. Mice with a conditional knockout of CD83 in DCs develop exacerbated colitis following dextran sodium sulfate challenge, whereas mucosal overexpression of CD83 inhibits DC inflammatory response and protects against colitis. These CD83 perturbations can be modeled in vitro where we show that CD83 homotypic interaction occurs via cell-cell contact and inhibits pro-inflammatory responses. CD83 knockdown or cytoplasmic truncation abrogates the effects of homotypic binding. We demonstrate that CD83 homotypic interaction regulates DC activation via the mitogen-activated protein kinase pathway by inhibiting p38α phosphorylation. Our findings indicate that CD83 homotypic interactions regulate DC activation and promote mucosal homeostasis.

Effects of exercise and milk fat globule membrane (MFGM) supplementation on body composition, physical function, and hematological parameters in community-dwelling frail Japanese women: a randomized double blind, placebo-controlled, follow-up trial

Objective

To investigate the combined and separate effects of exercise and milk fat globule membrane (MFGM) supplementation on frailty, physical function, physical activity level, and hematological parameters in community-dwelling elderly Japanese women.

Methods

A total of 131 frail, elderly women over 75 years were randomly assigned to one of four groups: exercise and MFGM supplementation (Ex+MFGM), exercise and placebo (Ex+Plac), MFGM supplementation, or the placebo group. The exercise group attended a 60-minute training program twice a week for three months, and the MFGM group ingested 1g of the MFGM supplement in pill form, daily for 3 months. The primary outcome measure was change in frailty status based on Fried’s frailty phenotype. Secondary outcome measures included body composition, physical function and hematological parameters, and interview survey components assessing lifestyle factors. Participants were followed for 4 months post-intervention.

Results

Significant group×time interactions were observed for usual walking speed (P = 0.005), timed up & go (P<0.001), and insulin-like growth factor-binding protein 3 / insulin-like growth factor 1 ratio (P = 0.013). The frailty components revealed that weight loss, exhaustion, low physical activity, and slow walking speed were reversed, but low muscle strength did not significantly changed. Frailty reversal rate was significantly higher in the Ex+MFGM (57.6%) than in the MFGM (28.1%) or placebo (30.3%) groups at post-intervention (χ² = 8.827, P = 0.032), and at the follow-up was also significantly greater in the Ex+MFGM (45.5%) and Ex+Plac (39.4%) groups compared with the placebo (15.2%) group (χ² = 8.607, P = 0.035). The exercise+MFGM group had the highest odds ratio (OR) for frailty reversal at post-intervention and follow-up (OR = 3.12, 95% confidence interval (CI) = 1.13–8.60; and OR = 4.67, 95% CI = 1.45–15.08, respectively).

Conclusion

This study suggests that interventions including exercise and nutrition can improve frailty status. Statistically significant additive effects of MFGM with exercise could not be confirmed in this population, and further investigation in larger samples is necessary.

Trial Registration

The Japan Medical Association Clinical Trial Registry (JMACCT)JMA-IIA00069

Dietary milk fat globule membrane improves endurance capacity in mice

Milk fat globule membrane (MFGM) comprises carbohydrates, membrane-specific proteins, glycoproteins, phospholipids, and sphingolipids. We evaluated the effects of MFGM consumption over a 12-wk period on endurance capacity and energy metabolism in BALB/c mice. Long-term MFGM intake combined with regular exercise improved endurance capacity, as evidenced by swimming time until fatigue, in a dose-dependent manner. The effect of dietary MFGM plus exercise was accompanied by higher oxygen consumption and lower respiratory quotient, as determined by indirect calorimetry. MFGM intake combined with exercise increased plasma levels of free fatty acids after swimming. After chronic intake of MFGM combined with exercise, the triglyceride content in the gastrocnemius muscle increased significantly. Mice given MFGM combined with exercise had higher mRNA levels of peroxisome proliferator-activated receptor-γ coactivator 1α (Pgc1α) and CPT-1b in the soleus muscle at rest, suggesting that increased lipid metabolism in skeletal muscle contributes, in part, to improved endurance capacity. MFGM treatment with cyclic equibiaxial stretch consisting of 10% elongation at 0.5 Hz with 1 h on and 5 h off increased the Pgc1α mRNA expression of differentiating C2C12 myoblasts in a dose-dependent manner. Supplementation with sphingomyelin increased endurance capacity in mice and Pgc1α mRNA expression in the soleus muscle in vivo and in differentiating myoblasts in vitro. These results indicate that dietary MFGM combined with exercise improves endurance performance via increased lipid metabolism and that sphingomyelin may be one of the components responsible for the beneficial effects of dietary MFGM.

Habitual exercise plus dietary supplementation with milk fat globule membrane improves muscle function deficits via neuromuscular development in senescence-accelerated mice

We examined the effects of habitual exercise plus nutritional intervention through consumption of milk fat globule membrane (MFGM), a milk component, on aging-related deficits in muscle mass and function in senescence-accelerated P1 mice. Combining wheel-running and MFGM (MFGMEx) intake significantly attenuated age-related declines in quadriceps muscle mass (control: 318 ± 6 mg; MFGMEx: 356 ± 9 mg; P < 0.05) and in contractile force (1.4-fold and 1.5-fold higher in the soleus and extensor digitorum longus muscles, respectively). Microarray analysis of genes in the quadriceps muscle revealed that MFGMEx stimulated neuromuscular development; this was supported by significantly increased docking protein-7 (Dok-7) and myogenin mRNA expression. Treatment of differentiating myoblasts with MFGM-derived phospholipid or sphingolipid fractions plus mechanical stretching also significantly increased Dok-7 mRNA expression. These findings suggest that habitual exercise plus dietary MFGM improves muscle function deficits through neuromuscular development, and that phospholipid and sphingolipid in MFGM contribute to its physiological actions.

Catechins suppress muscle inflammation and hasten performance recovery after exercise

INTRODUCTION

Catechins, abundant in green tea, exhibit many biological actions for potential clinical applications. Our purpose was to explore the potential benefits of catechin ingestion on recovery of physical performance after downhill running.

METHODS

Institute of Cancer Research mice were used to examine the effects of prior catechin ingestion (0.5% w/w in diet for 3 wk) on 1) wheel-running activity, 2) running endurance, 3) muscle force, and 4) muscle oxidative stress and inflammation after downhill running (16 m·min for 5 min, 18 m·min for 5 min, 20 m·min for 10 min, and 22 m·min for 130 min).

RESULTS

Voluntary wheel-running activity and the contractile force of the isolated soleus muscle decreased (P < 0.05) after downhill running. Notably, catechin ingestion significantly alleviated the running-induced decrease in voluntary wheel-running activity by 35%; the catechin-treated mice maintained endurance running capacity (214 ± 9 vs 189 ± 10 min, P < 0.05). Furthermore, catechins alleviated (P < 0.05) the decrease in tetanic force evident in the soleus muscle after downhill running. Catechins suppressed the running-induced increases in plasma creatine phosphokinase levels by 52%; this was also true of the carbonylated protein content of the soleus muscle by 17% (P < 0.05), malondialdehyde levels by 32% in the gastrocnemius muscle, and myeloperoxidase activity of the gastrocnemius by 22% (P < 0.05). The levels of tumor necrosis factor-α, interleukin-1β, and monocyte chemoattractant protein-1 in the gastrocnemius muscle were significantly lower (P < 0.05) by 33%, 29%, and 35%, respectively, in treated mice; the expression levels of mRNAs encoding these fell in parallel.

CONCLUSION

Our results suggest that long-term intake of catechins, perhaps through their antioxidant properties, attenuates downhill running-induced muscle damage by suppressing muscle oxidative stress and inflammation, hastening recovery of physical performance in mice.

TNF superfamily member TL1A elicits type 2 innate lymphoid cells at mucosal barriers

Immune responses at mucosal barriers are regulated by innate type 2 lymphoid cells (ILC2s) that elaborate effector cytokines interleukins 5 and 13 (IL5 and IL13). IL25 and IL33 are key cytokines that support ILC2s; however, mice deficient in these pathways retain some functional ILC2s. Analysis of human and murine cells revealed that ILC2s highly express tumor necrosis factor (TNF)-receptor superfamily member DR3 (TNFRSF25). Engagement of DR3 with cognate ligand TL1A promoted ILC2 expansion, survival, and function. Exogenous protein or genetic overexpression of TL1A activated ILC2s independent of IL25 or IL33. Dr3(-/-) mice failed to control gut helminthic infections, and failed to mount ILC2 responses in the lung after nasal challenge with papain. Our data demonstrate a key role for TL1A in promoting ILC2s at mucosal barriers.

Estimation of regional cerebral blood flow using N-isopropyl-p-123I iodoamphetamine acquisition data from the lungs and brain

Aim: Previously, we devised a method for estimating 123I labeled N-isopropyl-p-iodo- amphetamine (123I IMP) arterial blood activity at 10 minutes after intravenous injection of 123I IMP (Ca10) without any blood sampling using 123I IMP autoradiography (ARG) acquisition data, and verified its usefulness for quantification of regional cerebral blood flow (rCBF). In this study, we attempted to develop an improved noninvasive method for estimating rCBF. Patients, methods: 123I IMP studies with 23 patients and 15O-H2O positron emission tomography (PET) ARG studies with 20 patients were evaluated. Multiple regression analysis was used to estimate an integral of the arterial blood counts during the time after injection of 123I (JCa) using parameters from the time series of the lung counts and brain counts as the explanatory variables and the fraction [brain single-photon emission computed tomography (SPECT) average count / the mean of rCBFs (mean CBF) measured by 15O-H2O PET ARG method] as the objective variable. Results: The regression equation was as follows: Estimated JCa = (7.09x10-3 · Cb12) - (1.57x10-4 · CbpreSPECT) + (9.48x10-5 · CbpostSPECT) + (1.35x10-4· L15) - (6.95x10-4· L33) + (7.61x10-4· L81) - (0.417), where Cb12: brain count at 12 minutes, Cbpre-SPECT: brain count before SPECT, Cbpost-SPECT: brain count after SPECT, L15, L33, and L81: lung count at 15, 33, and 81 seconds, respectively. The mean CBF values (ml/min/100g) calculated using the estimated JCa values more closely correlated with those measured by 15O-H2O PET ARG method (r = 0.833, p < 0.01) than those obtained by our previous method (r = 0.590, p < 0.01). Conclusion: The rCBFs obtained by this method approximated more accurately to the values measured by 15O-H2O PET ARG method than those obtained by our previous method.

[Intraoperative direct angiography for the diminutive central pulmonary artery in a patient with major aortopulmonary collateral arteries]

It can be difficult to judge the degree of arborization of diminutive central pulmonary arteries (cPA) in patients with major aortopulmonary collateral arteries (MAPCA). Even through preoperative cardiac catheterization may not give adequate information. We introduce intra-operative direct angiography of diminutive cPA for patients with MAPCA. This would be one of the good options to judge the degree of arborization of the diminutive cPA, and to decide an initial surgical treatment. In this case, unifocalization of MAPCA without patch augmentation of pulmonary arteries, and an aortopulmonary shunt were performed at the 1st procedure. As enough growth of the cPA was obtained, this patient did not require additional patch augmentation of the pulmonary artery at the time of complete repair.

Opposing consequences of IL-23 signaling mediated by innate and adaptive cells in chemically induced colitis in mice

The interleukin-23 (IL-23) pathway has emerged as a promising therapeutic target for inflammatory bowel disease. Although the pathogenic role of IL-23 receptor (IL-23R) on T lymphocytes is well established, its function on innate immune cells has not been thoroughly examined. Here we investigate the consequence of IL-23R deletion in dextran sulfate sodium (DSS)-induced colitis. In IL23R(-/-) and IL23p19(-/-) mice, we observed decreased weight loss and reduced leukocyte infiltrate following DSS exposure. Surprisingly, when the IL-23R(-/-) allele was crossed into Rag2(-/-) mice, we observed exacerbated disease, increased epithelial damage, reduced pSTAT3 in the epithelium, and delayed recovery of IL23R(-/-)Rag2(-/-) mice. This phenotype was rescued with exogenous IL22-Fc, and epithelial pSTAT3 was restored. Depletion of Thy1(+) innate lymphoid cells eliminated the majority of IL-22 production in the colon lamina propria of DSS-treated Rag2(-/-) mice, suggesting that these are the major IL-23 responsive innate cells in this context. In summary, we provide evidence for opposing consequences of IL-23R on innate and adaptive lymphoid cells in murine colitis.

Catechins attenuate eccentric exercise-induced inflammation and loss of force production in muscle in senescence-accelerated mice

Catechins have a great variety of biological actions. We evaluated the potential benefits of catechin ingestion on muscle contractile properties, oxidative stress, and inflammation following downhill running, which is a typical eccentric exercise, in senescence-accelerated prone mice (SAMP). Downhill running (13 m/min for 60 min; 16° decline) induced a greater decrease in the contractile force of soleus muscle and in Ca(2+)-ATPase activity in SAMP1 compared with the senescence-resistant mice (SAMR1). Moreover, compared with SAMR1, SAMP1 showed greater downhill running-induced increases in plasma CPK and LDH activity, malondialdehyde, and carbonylated protein as markers of oxidative stress; and in protein and mRNA expression levels of the inflammatory mediators such as tumor necrosis factor-α and monocyte chemoattractant protein-1 in muscle. SAMP1 exhibited aging-associated vulnerability to oxidative stress and inflammation in muscle induced by downhill running. Long-term (8 wk) catechin ingestion significantly attenuated the downhill running-induced decrease in muscle force and the increased inflammatory mediators in both plasma and gastrocnemius muscle. Furthermore, catechins significantly inhibited the increase in oxidative stress markers immediately after downhill running, accompanied by an increase in glutathione reductase activity. These findings suggest that long-term catechin ingestion attenuates the aging-associated loss of force production, oxidative stress, and inflammation in muscle after exercise.

Tea catechins prevent contractile dysfunction in unloaded murine soleus muscle: a pilot study

OBJECTIVE

Extended periods of muscle disuse, physical inactivity, immobilization, and bedrest result in a loss of muscle mass and a decrease in muscle force, which are accompanied by an increase in oxidative stress. We investigated the effects of the intake of green tea catechins on unloading-induced muscle dysfunction in tail-suspended mice.

METHODS

Ten-week-old male BALB/c mice were fed a purified control diet or a diet containing 0.5% tea catechins for 14 d. Thereafter, the mice were subjected to continuous tail suspension for 10 d. On the final day, muscle mass, contractile force production, antioxidant potential, and carbonylated protein levels were evaluated.

RESULTS

Hind limb unloading caused a loss of soleus muscle weight and muscle force. Intake of tea catechins significantly inhibited the unloading-induced decrease in force in isolated soleus muscle by 19% compared with the control group, although tea catechins did not affect muscle weight. In addition, intake of tea catechins suppressed the decrease in antioxidant potential and the increase in carbonyl myofibrillar protein.

CONCLUSION

Ingestion of tea catechins minimized contractile dysfunction in skeletal muscle and muscle atrophy in unloaded muscle. This effect might be partly due to the lower oxidative modification of myofibrillar protein through the antioxidant activity of tea catechins.

Aging-associated changes in physical performance and energy metabolism in the senescence-accelerated mouse

The aim of the study was to clarify the aging-associated changes in physical performance and energy metabolism in senescence-accelerated prone mouse (SAMP1). The endurance of aged SAMP1 was significantly lower by 28% than the age-matched senescence-resistant mouse (SAMR1). Oxygen consumption and fat oxidation in aged SAMP1 were lower by 19% and 22%, respectively. Peroxisome proliferator-activated receptor-γ coactivator-1β and medium-chain acyl coenzyme A dehydrogenase messenger RNA expression was significantly lower in aged SAMP1. Aged SAMP1 exhibited higher plasma glucose, insulin, leptin, and lower adiponectin concentrations. Aged SAMP1 also had higher malondialdehyde levels in plasma and tissues and lower peroxisome proliferator-activated receptor-γ messenger RNA and protein levels in adipose tissue. These results indicate that physical performance and energy expenditure decrease earlier with aging in SAMP1, accompanied by decreased fatty acid catabolism in muscle and liver and increased inflammation and oxidative stress in adipose tissue. SAMP1 could thus be a useful accelerated functional depression model for studying physical performance and energy metabolism.

Different contribution of muscle and liver lipid metabolism to endurance capacity and obesity susceptibility of mice

We investigated strain differences in whole body energy metabolism, peripheral lipid metabolism, and energy metabolism-related gene expression and protein levels in BALB/c, C57BL/6J, and A/J mice to evaluate the relationship between endurance capacity, susceptibility to diet-induced obesity, and differences in lipid metabolism in muscle and liver. A high-fat diet significantly increased body weight and fat weight in C57BL/6J mice, but not in BALB/c and A/J mice. The endurance capacity of BALB/c mice was 52% greater than that of C57BL/6J mice and 217% greater than that of A/J mice. The respiratory exchange ratio was lowest in BALB/c mice, higher in C57BL/6J mice, and highest in A/J mice, which inversely correlated with the endurance capacity and fatty acid β-oxidation activity in the muscle. Plasma lactate levels measured immediately after exercise were lowest in BALB/c mice and highest in A/J mice, although there was no difference under resting conditions, suggesting that carbohydrate breakdown is suppressed by enhanced fat utilization during exercise in BALB/c mice. On the other hand, the body weight increase induced by high-fat feeding was related to a reduced whole body energy expenditure, higher respiratory quotient, and lower fatty acid β-oxidation activity in the liver. In addition, β-oxidation activity in the muscle and liver roughly paralleled the mRNA and protein levels of lipid metabolism-related molecules, such as peroxisome proliferator-activated receptor and medium-chain acyl-CoA dehydrogenase, in each tissue. These findings indicate that genetically determined basal muscle and liver lipid metabolism and responsiveness to exercise influence physical performance and obesity susceptibility.

Tea catechin ingestion combined with habitual exercise suppresses the aging-associated decline in physical performance in senescence-accelerated mice

Catechins, which are abundant in green tea, possess a variety of biologic actions, and their clinical application has been extensively investigated. In this study, we examined the effects of tea catechins and regular exercise on the aging-associated decline in physical performance in senescence-accelerated prone mice (SAMP1) and age-matched senescence-accelerated resistant mice (SAMR1). The endurance capacity of SAMR1 mice, measured as the running time to exhaustion, tended to increase over the 8-wk experimental period, whereas that of SAMP1 mice decreased by 17%. On the other hand, the endurance capacity of SAMP1 mice fed 0.35% (wt/wt) catechins remained at the initial level and was significantly higher than that of SAMP1 mice not fed catechins. In SAMP1 mice fed catechins and given exercise, oxygen consumption was significantly increased, and there was an increase in skeletal muscle fatty acid β-oxidation. The mRNA levels of mitochondria-related molecules, such as peroxisome proliferator-activated receptor-γ coactivator-1, cytochrome c oxidase-II, III, and IV in skeletal muscle were also higher in SAMP1 mice given both catechins and exercise. Moreover, oxidative stress measured as thiobarbituric reactive substances was lower in SAMP1 groups fed catechins than in the SAMP1 control group. These results suggest that long-term intake of catechins, together with habitual exercise, is beneficial for suppressing the aging-related decline in physical performance and energy metabolism and that these effects are due, at least in part, to improved mitochondrial function in skeletal muscle.

Dietary diacylglycerol induces the regression of atherosclerosis in rabbits

Recent studies of the relation between serum triacylglycerol concentration and the risk for coronary artery disease suggest that inefficient clearance of postprandial triacylglycerols promotes atherogenesis. We recently demonstrated that dietary diacylglycerol (DAG), rich in the 1,3-species, suppresses the postprandial increase in serum triacylglycerol levels compared with dietary triacylglycerol (TAG). Here, we investigated the effects of dietary DAG on atherosclerosis in rabbits with cholesterol-induced atherosclerosis. New Zealand White rabbits (n = 20) were fed a diet containing 3% lard and 1.3% cholesterol for 50 d to induce atherosclerotic lesions. Thereafter, the rabbits were assigned to 2 groups and fed 90 g/d nonpurified diet and orally administered 5 g DAG or TAG for an additional 34 d. Reference rabbits (n = 5) were fed only the nonpurified diet throughout the 84-d study. The area of atherosclerotic lesions and aortic lipid concentrations were significantly lower in DAG-fed rabbits compared with TAG-fed rabbits. The VLDL receptor and macrophage antigen-1 mRNA expression levels were significantly lower in DAG-fed rabbits than in TAG-fed rabbits. In the liver of DAG-fed rabbits, the triacylglycerol concentration was lower and the carnitine palmitoyltransferase activity higher than in TAG-fed rabbits. Stimulation of hepatic lipid catabolism might be related to the reduced lipid accumulation in the liver and aorta by reducing the release of triacylglycerol into the circulation. Thus, long-term consumption of DAG, which reduces postprandial lipemia, might be useful for the regression of atherosclerosis by stimulating hepatic lipid catabolism and thereby modulating monocyte/macrophage migration and aortic lipid accumulation.