Branched-chain amino acid-enriched nutritional support in surgical and cancer patients

Improvement of branched-chain amino acid production by isolated high-producing protease from Bacillus amyloliquefaciens NY130 on isolated soy/whey proteins and their muscle cell protection

Branched-chain amino acids (BCAAs) are vital components of human and animal nutrition that contribute to the building blocks of proteins. In this study, 170 protease-producing strains were isolated and screened from soy-fermented foods. Bacillus amyloliquefaciens NY130 was obtained from Cheonggukjang with high production of BCAAs. Optimal production of protease from B. amyloliquefaciens NY130 (protease NY130) was achieved at 42 °C and pH 6.0 for 21 h. It was purified and determined as 27- and 40 kDa. Protease NY130 showed maximum activity at pH 9.0 and 45 °C with Km value of 10.95 mg for ISP and 1.69 mg for WPI. Protease-treated ISP and WPI showed increased sweetness and saltiness via electronic tongue analysis and enhanced the protective effect against oxidative stress in C2C12 myocytes by increasing p-mTOR/mTOR protein expression to 160%. This work possesses potential in producing BCAAs by using protease for utilization in food.

BCAAs acutely drive glucose dysregulation and insulin resistance: role of AgRP neurons

BACKGROUND

High-protein diets are often enriched with branched-chain amino acids (BCAAs) known to enhance protein synthesis and provide numerous physiological benefits, but recent studies reveal their association with obesity and diabetes. In support of this, protein or BCAA supplementation is shown to disrupt glucose metabolism while restriction improves it. However, it is not clear if these are primary, direct effects of BCAAs or secondary to other physiological changes during chronic manipulation of dietary BCAAs.

METHODS

Three-month-old C57Bl/6 mice were acutely treated with either vehicle/BCAAs or BT2, a BCAA-lowering compound, and detailed in vivo metabolic phenotyping, including frequent sampling and pancreatic clamps, were conducted.

RESULTS

Using a catheter-guided frequent sampling method in mice, here we show that a single infusion of BCAAs was sufficient to acutely elevate blood glucose and plasma insulin. While pre-treatment with BCAAs did not affect glucose tolerance, a constant infusion of BCAAs during hyperinsulinemic-euglycemic clamps impaired whole-body insulin sensitivity. Similarly, a single injection of BT2 was sufficient to prevent BCAA rise during fasting and markedly improve glucose tolerance in high-fat-fed mice, suggesting that abnormal glycemic control in obesity may be causally linked to high circulating BCAAs. We further show that chemogenetic over-activation of AgRP neurons in the hypothalamus, as present in obesity, significantly impairs glucose tolerance that is completely normalized by acute BCAA reduction. Interestingly, most of these effects were demonstrated only in male, but not in female mice.

CONCLUSION

These findings suggest that BCAAs per se can acutely impair glucose homeostasis and insulin sensitivity, thus offering an explanation for how they may disrupt glucose metabolism in the long-term as observed in obesity and diabetes. Our findings also reveal that AgRP neuronal regulation of blood glucose is mediated through BCAAs, further elucidating a novel mechanism by which brain controls glucose homeostasis.

Effect of perioperative branched chain amino acids supplementation in liver cancer patients undergoing surgical intervention: A systematic review

BACKGROUND

Branched chain amino acid (BCAA) supplementation has been associated with favourable outcomes in liver malignancies requiring definitive resection or liver transplantation. Currently, there are no updated systematic reviews evaluating the efficacy of perioperative BCAA supplementation in patients undergoing surgery for liver cancer.

AIM

To evaluate the efficacy of perioperative BCAA supplementation in patients undergoing surgery for liver cancer.

METHODS

A systematic review of randomized control trials and observational studies was conducted on PubMed, Embase, Cochrane Library, Scopus, and Web of Science to evaluate the effect of perioperative BCAA supplementation compared to standard in-hospital diet, in liver cancer patients undergoing surgery. Clinical outcomes were extracted, and a meta-analysis was performed on relevant outcomes.

RESULTS

16 studies including 1389 patients were included. Perioperative BCAA administration was associated with reduced postoperative infection [risk ratio (RR) = 0.58 95% confidence intervals (CI): 0.39 to 0.84, P = 0.005] and ascites [RR = 0.57 (95%CI: 0.38 to 0.85), P = 0.005]. There was also a reduction in length of hospital stay (LOS) [weighted mean difference (WMD) = -3.03 d (95%CI: -5.49 to -0.57), P = 0.02] and increase in body weight [WMD = 1.98 kg (95%CI: 0.35 to 3.61, P = 0.02]. No significant differences were found in mortality, cancer recurrence and overall survival. No significant safety concerns were identified.

CONCLUSION

Perioperative BCAA administration is efficacious in reducing postoperative infection, ascites, LOS, and increases body weight in liver cancer patients undergoing surgical resection.

The combination of quercetin and leucine synergistically improves grip strength by attenuating muscle atrophy by multiple mechanisms in mice exposed to cisplatin

Both quercetin and leucine have been shown to exert moderately beneficial effects in preventing muscle atrophy induced by cancers or chemotherapy. However, the combined effects of quercetin and leucine, as well as the possible underlying mechanisms against cisplatin (CDDP)-induced muscle atrophy and cancer-related fatigue (CRF) remain unclear. To investigate the issues, male BALB/c mice were randomly assigned to the following groups for 9 weeks: Control, CDDP (3 mg/kg/week), CDDP+Q (quercetin 200 mg/kg/day administrated by gavage), CDDP+LL (a diet containing 0.8% leucine), CDDP+Q+LL, CDDP+HL (a diet containing 1.6% leucine), and CDDP+Q+HL. The results showed that quercetin in combination with LL or HL synergistically or additively attenuated CDDP-induced decreases in maximum grip strength, fat and muscle mass, muscle fiber size and MyHC level in muscle tissues. However, the combined effects on locomotor activity were less than additive. The combined treatments decreased the activation of the Akt/FoxO1/atrogin-1/MuRF1 signaling pathway (associated with muscle protein degradation), increased the activation of the mTOR and E2F-1 signaling pathways (associated with muscle protein synthesis and cell cycle/growth, respectively). The combined effects on signaling molecules present in muscle tissues were only additive or less. In addition, only Q+HL significantly increased glycogen levels compared to the CDDP group, while the combined treatments considerably decreased CDDP-induced proinflammatory cytokine and MCP-1 levels in the triceps muscle. Using tumor-bearing mice, we demonstrated that the combined treatments did not decrease the anticancer effect of CDDP. In conclusion, this study suggests that the combination of quercetin and leucine enhanced the suppressed effects on CDDP-induced muscle weakness and CRF through downregulating muscle atrophy and upregulating the glycogen level in muscle tissues without compromising the anticancer effect of CDDP. Multiple mechanisms, including regulation of several signaling pathways and decrease in proinflammatory mediator levels in muscles may contributed to the enhanced protective effect of the combined treatments on muscle atrophy.

Branched-Chain Amino Acids and Insulin Resistance, from Protein Supply to Diet-Induced Obesity

For more than a decade, there has been a wide debate about the branched-chain amino acids (BCAA) leucine, valine, and isoleucine, with, on the one hand, the supporters of their anabolic effects and, on the other hand, those who suspect them of promoting insulin resistance. Indeed, the role of leucine in the postprandial activation of protein synthesis has been clearly established, even though supplementation studies aimed at taking advantage of this property are rather disappointing. Furthermore, there is ample evidence of an association between the elevation of their plasma concentrations and insulin resistance or the risk of developing type 2 diabetes, although there are many confounding factors, starting with the level of animal protein consumption. After a summary of their metabolism and anabolic properties, we analyze in this review the factors likely to increase the plasma concentrations of BCAAs, including insulin-resistance. After an analysis of supplementation or restriction studies in search of a direct role of BCAAs in insulin resistance, we discuss an indirect role through some of their metabolites: branched-chain keto acids, C3 and C5 acylcarnitines, and hydroxyisobutyrate. Overall, given the importance of insulin in the metabolism of these amino acids, it is very likely that small alterations in insulin sensitivity are responsible for a reduction in their catabolism long before the onset of impaired glucose tolerance.

Nutrition Care in Cancer Surgery Patients: A Narrative Review of Nutritional Screening and Assessment Methods and Nutritional Considerations

Malignancy is a catabolic state, which is precipitated with surgical intervention. Malnutrition is one of the main risk factors for poor outcomes of cancer surgery. We need to screen oncological patients for malnutrition using standardized screening tools, by which patients found to be at nutritional risk are then referred to a registered dietitian for further management. A detailed assessment is required in such patients, which helps in categorizing the patients based on the severity and rendering proper care. Preoperative nutrition care is often overlooked because of the urgency of operating on a cancer patient. Still, studies have shown preoperative nutritional building gives better surgical outcomes and good postoperative quality of life. Preoperative nutrition care includes both early and late preoperative care. For efficient preoperative nutrition care publishing, standard operating procedures at every healthcare center are recommended. Postoperative nutrition care is given to build the patient tackle the surgical trauma, and their diet mainly includes protein to minimize catabolism. Regardless of the route of nutrition delivery, providing appropriate nutrition care in the postoperative period improves cancer patients' condition drastically. Early postoperative nutrition is studied in different cancer surgeries and is considered ideal in cancer surgical patients. There is a need for consensus on the composition of postoperative nutrition. The diet of a cancer patient should include micronutrients like vitamins D and B and minerals along with the usual nutrition care. The use of special diets like branched-chain amino acids and immune nutrition is to be considered on a case-by-case basis and introducing them into the routine care of a patient needs to be studied extensively.

An umbrella review of systematic reviews of β-hydroxy-β-methyl butyrate supplementation in ageing and clinical practice

The compound β-hydroxy-β-methyl butyrate (HMB) is proposed to increase or mitigate the loss of skeletal muscle and improve muscle function. We undertook a review of systematic reviews of HMB supplementation to promote gains or mitigate muscle loss in ageing and clinical populations. Following PRISMA guidelines, we searched for systematic reviews reporting the effect of HMB in our target populations. Dual-energy X-ray absorptiometry (DXA) measured lean soft-tissue mass (LSTM) was accepted as a proxy for muscle. We identified 15 systematic reviews that met our inclusion criteria, which were independently evaluated. The methodological quality of the reviews was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR), and standardized effectiveness statements were generated. Five of 15 studies found some evidence that HMB augmented LSTM; the remaining 10 studies reported some evidence favouring no difference (6/10 studies) or insufficient evidence to determine an effect (4/10 studies). Of the 12 studies that evaluated strength, 4/12 found some evidence, 5/12 found some evidence of no effect with one article finding some evidence in favour of patients in peri-hospitalized and no evidence for those that are community-dwelling, 4/12 had insufficient evidence to determine an effect, and 1/12 had insufficient evidence. No]study reported a positive effect of HMB on physical function; however, 2/10 studies found some evidence favouring no effect, and 7/10 studies reported insufficient evidence to determine an effect. The effectiveness of HMB supplementation in augmenting LSTM was heterogeneous, with most reviews finding no effect or inconclusive evidence to determine an effect. Most reviews concluded that HMB supplementation did not affect strength outcome measures or studies were inconclusive. The current evidence is insufficient to assess the impact of HMB supplementation on functional outcome measures. Our analysis shows minor, inconsistent support for HMB as part of an oral nutritional supplement or as a stand-alone supplement (or combined with other amino acids) to increase or promote retention of LSTM, improve strength, and no evidence that it improves physical function in older persons or clinical populations.

Leucine Supplementation in Cancer Cachexia: Mechanisms and a Review of the Pre-Clinical Literature

Cancer cachexia (CC) is a complex syndrome of bodily wasting and progressive functional decline. Unlike starvation, cachexia cannot be reversed by increased energy intake alone. Nonetheless, targeted nutritional support is a necessary component in multimodal syndrome management. Due to the highly catabolic nature of cancer cachexia, amino acid supplementation has been proposed. Interestingly, leucine has been found to increase protein synthesis and decrease protein degradation via mTORC1 pathway activation. Multiple pre-clinical studies have explored the impact of leucine supplementation in cachectic tumor-bearing hosts. Here, we provide an overview of leucine’s proposed modes of action to preserve lean mass in cachexia and review the current pre-clinical literature related to leucine supplementation during CC. Current research indicates that a leucine-rich diet may attenuate CC symptomology; however, these works are difficult to compare due to methodological differences. There is need for further pre-clinical work exploring leucine’s potential ability to modulate protein turnover and immune response during CC, as well as the impact of additive leucine on tumor growth.

Impact of probiotic Limosilactobacillus reuteri DSM 17938 on amino acid metabolism in the healthy newborn mouse

We studied the effect of feeding a single probiotic Limosilactobacillus reuteri DSM 17938 (LR 17938) on the luminal and plasma levels of amino acids and their derivatives in the suckling newborn mouse, using gas chromatography and high-performance liquid chromatography. We found that LR 17938 increased the relative abundance of many amino acids and their derivatives in stool, while it simultaneously significantly reduced the plasma levels of three amino acids (serine, citrulline, and taurine). Many peptides and dipeptides were increased in stool and plasma, notably gamma-glutamyl derivatives of amino acids, following ingestion of the LR 17938. Gamma-glutamyl transformation of amino acids facilitates their absorption. LR 17938 significantly upregulated N-acetylated amino acids, the levels of which could be useful biomarkers in plasma and warrant further investigation. Specific fecal microbiota were associated with higher levels of fecal amino acids and their derivatives. Changes in luminal and circulating levels of amino acid derivatives, polyamines, and tryptophan metabolites may be mechanistically related to probiotic efficacy.

The Effects of an Oral Nutritional Supplement with Whey Peptides and Branched-Chain Amino Acids for Cardiac Rehabilitation of Patients with Chronic Heart Failure

The aim of the present study was to determine whether the addition of an oral nutritional supplement with whey peptides and branched-chain amino acids for cardiac rehabilitation improves cardiopulmonary function, skeletal muscle function, and metabolism in CHF patients.In this randomized, parallel-group comparative pilot study, 20 CHF patients were randomly assigned to the nutrition group (n = 10) or the control group (n = 10). At baseline and 12 weeks, we performed physical examinations, motor function evaluation, clinical laboratory tests, nutritional status assessment, and echocardiography. The primary outcome was exercise tolerance, as determined by the cardiopulmonary stress test (CPX), 6-minute walking test (6MWT), and brain natriuretic peptide (BNP) levels.During follow-up, body weight, body mass index, total muscle mass, and total lean mass did not change significantly in either group. The total fat mass significantly increased in the nutrition group (14.3 ± 5.4 kg versus 16.1 ± 5.5 kg, P < 0.001) but did not change in the control group, and the difference in the changes in total fat mass between groups was significant (-0.26 ± 0.96 kg versus 1.49 ± 0.63 kg, P < 0.001). The peakVO₂ and 6-minute walk test (6 MWT) significantly increased in the nutrition group (14.6 ± 3.4 mL/minute/kg versus 15.8 ± 3.8 mL/minute/kg, P = 0.029; 346.9 ± 103.1 m versus 382.7 ± 102.1 m, P = 0.048; respectively) but did not change in the control group. The changes in peakVO₂ and 6MWT did not significantly differ between the groups.The oral nutritional supplement for the treatment of CHF was effective for cardiac rehabilitation in terms of fat mass and exercise capacity.The present study demonstrated that oral nutritional supplements with whey peptides and branched-chain amino acid (BCAA) for cardiac rehabilitation in patients with chronic heart failure (CHF) increased fat mass and exercise capacity. We conclude that whey peptides and BCAA supplementation may be a useful treatment for CHF patients.

Effects of Branched-chain Amino Acids on Nutritional Metabolism and Pharmacoeconomics in Patients with Severe Abdominal Trauma

OBJECTIVE

To observe the influences of branched-chain amino acids (BCAAs) on nutrition metabolism and prognosis of patients with severe abdominal trauma; at the same time, to analyze and evaluate the pharmacoeconomics of it.

METHODS

A total of 75 severe abdominal trauma patients were recruited from June 2016 to December 2017 and randomly divided into control group and observation group. After surgery and basic treatment, parenteral nutrition support therapy with iso-nitrogen and iso-calorie of both groups was administered. Meanwhile, an equivalent of 8.5% (18AA-II) and 10% (20AA) compound AA injection was administrated to the control and observation groups, respectively. The nitrogen balance, serum protein level and plasma amino spectrum of the patients were observed before and after treatment. Besides, the hospital stay, survival rate, complications, adverse reactions and hospitalization costs were also compared.

RESULTS

After a 7-day course treatment, the nitrogen balance level of the two groups was significantly improved, but no significant difference was found between them. In addition, the serum protein level and plasma amino spectrum of the two groups was generally improved when compared to before treatment. Compared with the control group, the level of albumin and transferrin in the observation group was improved significantly after treatment, while no difference in plasma amino spectrum was found between the two groups. Moreover, the cost analysis showed remarkably reduced hospitalization costs in the observation group.

CONCLUSION

To a certain degree, BCAAs could improve the nutritional metabolism and prognosis of patients with severe abdominal trauma, and have good cost-effectiveness.

Effects of different branched-chain amino acids supplementation protocols on the inflammatory response of LPS-stimulated RAW 264.7 macrophages

Although branched-chain amino acids (BCAA) are commonly used as a strategy to recover nutritional status of critically ill patients, recent findings on their role as immunonutrients have been associated with unfavorable outcomes, especially in obese patients. The present study aimed to explore the effects of different BCAA supplementation protocols in the inflammatory response of LPS-stimulated RAW 264.7 macrophages. Cell cultures were divided into five groups, with and without BCAA supplementation, (2 mmol/L of each amino acid). Then, cell cultures followed three different treatment protocols, consisting of a pretreatment (PT), an acute treatment (AT), and a chronic treatment (CT) with BCAA and LPS stimulation (1 µg/mL). Cell viability was analyzed by MTT assay, NO production was assessed by the Griess reaction and IL-6, IL-10, TNF-α and PGE2 synthesis, was evaluated by ELISA. BCAA significantly increased cell viability in AT and CT protocols, and NO and IL-10 synthesis in all treatment protocols. IL-6 synthesis was only increased in PT and CT protocols. TNF-α and PGE2 synthesis were not altered in any of the protocols and groups. BCAA supplementation was able to increase both pro and anti-inflammatory mediators synthesis by RAW 264.7 macrophages, which was influenced by the protocol applied. Moreover, these parameters were significantly increased by isoleucine supplementation, highlighting a potential research field for future studies.

Are Supplemental Branched-Chain Amino Acids Beneficial During the Oncological Peri-Operative Period: A Systematic Review and Meta-Analysis

BACKGROUND

Branched-chain amino acids (BCAAs; leucine, isoleucine, and valine) are essential amino acids involved in immune responses, and may have roles in protein malnutrition and sarcopenia. Furthermore, certain liver diseases have been associated with a decreased Fischer's ratio (BCAAs to aromatic amino acids; phenylalanine, tyrosine, and tryptophan). We aimed to evaluate the safety and efficacy of BCAAs use in patients with cancer undergoing surgery.

METHODS

MEDLINE, Embase, and CENTRAL were searched (inception to July 24, 2020) for randomized controlled trials (RCTs) and comparative observational studies in English evaluating BCAAs (alone or in combinations) during the oncological peri-operative period. Study selection, data extraction, and quality appraisal were done in duplicate. RCT risk-of-bias was appraised using Cochrane Risk-of-Bias tool, and observational studies' quality assessment was conducted with Newcastle-Ottawa Scale. Meta-analyses were conducted when appropriate.

RESULTS

20 articles were included comprising 13 RCTs and 6 observational cohort studies in 7 reports and 2019 total participants overall. Among 13 RCTs, 77% involved liver cancer. Methodological study quality scored substantial risk-of-bias across most RCTs. Meta-analysis of RCTs found a 38% decreased risk of post-operative infections in BCAAs group compared to controls (RR = 0.62; 95% CI = 0.44 to 0.87; P = .006; number of RCTs, k = 6; total sample size, N = 389; I² = 0%). BCAAs were also found to be beneficial for ascites (RR = 0.55; 95% CI = 0.35 to 0.86; P = .008; k = 4; N = 296; I² = 0%), body weight (MD = 3.24 kg; 95% CI = 0.44 to 6.04; P = .02; k = 3; N = 196; I² = 24%), and hospitalization length (MD = -2.07 days; 95% CI = -3.97 to -0.17; P = .03; k = 5; N = 362; I² = 59%). No differences were found between BCAAs and controls for mortality, recurrence, other post-operative complications (liver failure, edema, pleural effusion), blood loss, quality of life, ammonia level, and prothrombin time. No serious adverse events were related to BCAAs; however, serious adverse events were reported due to intravenous catheters. No safety concerns from observational studies were identified.

CONCLUSIONS

Branched-chain amino acids during the oncological surgical period demonstrated promise in reducing important post-operative morbidity from infections and ascites compared to controls. Blinded, placebo-controlled confirmatory trials of higher methodological quality are warranted, especially using oral, short-term BCAAs-enriched supplements within the context of recent ERAS programs.

PROSPERO REGISTRATION

CRD42018086168.

Central Regulation of Branched-Chain Amino Acids Is Mediated by AgRP Neurons

Circulating branched-chain amino acids (BCAAs) are elevated in obesity and diabetes, and recent studies support a causal role for BCAAs in insulin resistance and defective glycemic control. The physiological mechanisms underlying BCAA regulation are poorly understood. Here we show that insulin signaling in the mediobasal hypothalamus (MBH) of rats is mandatory for lowering plasma BCAAs, most probably by inducing hepatic BCAA catabolism. Insulin receptor deletion only in agouti-related protein (AgRP)-expressing neurons (AgRP neurons) in the MBH impaired hepatic BCAA breakdown and suppression of plasma BCAAs during hyperinsulinemic clamps in mice. In support of this, chemogenetic stimulation of AgRP neurons in the absence of food significantly raised plasma BCAAs and impaired hepatic BCAA degradation. A prolonged fasting or ghrelin treatment recapitulated designer receptors exclusively activated by designer drugs-induced activation of AgRP neurons and increased plasma BCAAs. Acute stimulation of vagal motor neurons in the dorsal motor nucleus was sufficient to decrease plasma BCAAs. Notably, elevated plasma BCAAs were associated with impaired glucose homeostasis. These findings suggest a critical role of insulin signaling in AgRP neurons for BCAA regulation and raise the possibility that this control may be mediated primarily via vagal outflow. Furthermore, our results provide an opportunity to closely examine the potential mechanistic link between central nervous system-driven BCAA control and glucose homeostasis.

Important determinants to take into account to optimize protein nutrition in the elderly: solutions to a complex equation

During ageing, skeletal muscle develops anabolic resistance towards the stimulation of protein synthesis induced by dietary amino acids. The stimulation of muscle protein synthesis after food intake remains insufficient, even with a protein intake recommended for healthy adults. This alteration is one of the mechanisms known to be responsible for the decrease of muscle mass and function during ageing, namely sarcopenia. Increasing dietary protein intake above the current RDA(0⋅83 g/kg/d) has been strongly suggested to overcome the anabolic resistance observed. It is also specified that the dietary protein ingested should be of good quality. A protein of good quality is a protein whose amino acid (AA) composition covers the requirement of each AA when ingested at the RDA. However, the biological value of proteins may vary among dietary sources in which AA composition could be unbalanced. In the present review, we suggest that the quality of a dietary protein is also related to several other determinants. These determinants include the speed of digestion of dietary proteins, the presence of specific AA, the food matrix in which the dietary proteins are included, the processes involved in the production of food products (milk gelation and cooking temperature), the energy supply and its nature, and the interaction between nutrients before ingestion. Particular attention is given to plant proteins for nutrition of the elderly. Finally, the timing of protein intake and its association with the desynchronized intake of energetic nutrients are discussed.

A Special Amino-Acid Formula Tailored to Boosting Cell Respiration Prevents Mitochondrial Dysfunction and Oxidative Stress Caused by Doxorubicin in Mouse Cardiomyocytes

Anthracycline anticancer drugs, such as doxorubicin (DOX), can induce cardiotoxicity supposed to be related to mitochondrial damage. We have recently demonstrated that a branched-chain amino acid (BCAA)-enriched mixture (BCAAem), supplemented with drinking water to middle-aged mice, was able to promote mitochondrial biogenesis in cardiac and skeletal muscle. To maximally favor and increase oxidative metabolism and mitochondrial function, here we tested a new original formula, composed of essential amino acids, tricarboxylic acid cycle precursors and co-factors (named α5), in HL-1 cardiomyocytes and mice treated with DOX. We measured mitochondrial biogenesis, oxidative stress, and BCAA catabolic pathway. Moreover, the molecular relevance of endothelial nitric oxide synthase (eNOS) and mechanistic/mammalian target of rapamycin complex 1 (mTORC1) was studied in both cardiac tissue and HL-1 cardiomyocytes. Finally, the role of Krüppel-like factor 15 (KLF15), a critical transcriptional regulator of BCAA oxidation and eNOS-mTORC1 signal, was investigated. Our results demonstrate that the α5 mixture prevents the DOX-dependent mitochondrial damage and oxidative stress better than the previous BCAAem, implying a KLF15/eNOS/mTORC1 signaling axis. These results could be relevant for the prevention of cardiotoxicity in the DOX-treated patients.

Muscle protein anabolism in advanced cancer patients: response to protein and amino acids support, and to physical activity

In the field of oncology, it is well recognized that a decrease in mass, density, strength, or function of skeletal muscle is associated to increased treatment toxicities and postoperative complications, as well as poor progression-free survival and overall survival. The ability of amino acids to stimulate protein synthesis in cancer patients is reduced. Considering nutritional intervention, this anabolic resistance could be in a part counteracted by increasing protein or by giving specific amino acids. In particular, Leucine might counteract this anabolic resistance not only by increasing substrate availability, but also by directly modulating the anabolic signal pathway. Few studies showed the possibility of increasing muscle protein synthesis by specific nutriments and/or by increasing amino acids or protein administration. In addition, whereas many studies provide evidence of a benefit of adapted physical activity in advanced cancer patients, it is difficult to specify the most appropriate type of exercise, and the optimum rhythm and intensity. Moreover, the benefits of physical activities and of protein support seem greater when it is started at the precachexia stage rather than at the cachexia stage, and their benefits are limited or nonexistent at the stage of refractory cachexia. Future approaches should integrate the combination of several complementary treatments in order to prevent (or improve) cachexia and/or sarcopenia in cancer patients.

Recent Progress on Branched-Chain Amino Acids in Obesity, Diabetes, and Beyond

Branched-chain amino acids (BCAAs) are essential amino acids that are not synthesized in our body; thus, they need to be obtained from food. They have shown to provide many physiological and metabolic benefits such as stimulation of pancreatic insulin secretion, milk production, adipogenesis, and enhanced immune function, among others, mainly mediated by mammalian target of rapamycin (mTOR) signaling pathway. After identified as a reliable marker of obesity and type 2 diabetes in recent years, an increasing number of studies have surfaced implicating BCAAs in the pathophysiology of other diseases such as cancers, cardiovascular diseases, and even neurodegenerative disorders like Alzheimer's disease. Here we discuss the most recent progress and review studies highlighting both correlational and potentially causative role of BCAAs in the development of these disorders. Although we are just beginning to understand the intricate relationships between BCAAs and some of the most prevalent chronic diseases, current findings raise a possibility that they are linked by a similar putative mechanism.

Targeting HIBCH to reprogram valine metabolism for the treatment of colorectal cancer

Valine catabolism is known to be essential for cancer cells but the detailed mechanism remains unclear. This study is to explore the critical roles of 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) in colorectal cancers (CRC) and to develop a new therapy returning valine metabolism homeostasis. High HIBCH expression was first confirmed to correlate with poor survival in patients with CRC, which was then linked to the increased cell growth, resistant apoptosis, and decreased autophagy in CRC cells. The functions of HIBCH in CRC were dependent on its mitochondrial localization. High HIBCH level was further demonstrated to promote the metabolism of tricarboxylic acid cycle as well as oxidative phosphorylation in CRC cells. Based on above findings, we further discovered a novel valine catabolism inhibitor SBF-1. The pharmacological blockade of HIBCH mitochondrial localization with SBF-1 resulted in decreased cancer cell growth and increased autophagy, collectively contributing to the antitumor effect both in vitro and in vivo. Moreover, anti-VEGF therapy with bevacizumab increased HIBCH level in CRC cells, which in turn caused the resistance to the therapy. The interference with HIBCH function by SBF-1 significantly increased the antitumor efficacy of bevacizumab and led to a robust survival benefit. The present study identified HIBCH as a critical enzyme of valine catabolism in CRC progression and resistance to anti-VEGF therapy. We also provided a novel HIBCH inhibitor SBF-1, which highlighted the combined therapy using valine catabolic inhibitor along with anti-VEGF drugs, to control progression of CRC.

The effect of the branched-chain amino acids on the in-vitro activity of bovine intestinal alkaline phosphatase

Branched-chain amino acids (BCAA) are used as nutritional support for patients with a range of conditions including liver cirrhosis and in-born errors of amino acid metabolism, and they are commonly used “sports” or exercise supplements. The effects of the BCAA on the in-vitro activity of calf intestinal alkaline phosphatase (EC. 3.1.3.1) were studied. All three BCAA were found to be uncompetitive inhibitors of the enzyme with L-leucine being the most potent ([Formula: see text] = 24.9 mmol/L) and L-valine, the least potent ([Formula: see text] = 37 mmol/L). Mixed BCAA are able to act in combination to inhibit the enzyme. Given the important role of intestinal alkaline phosphatase in gut homeostasis, these findings have potential implications for those taking high levels of BCAA as supplements.

Post Meal Energy Boluses Do Not Increase the Duration of Muscle Protein Synthesis Stimulation in Two Anabolic Resistant Situations

BACKGROUND

When given in the long term, whey proteins alone do not appear to be an optimal nutritional strategy to prevent or slow down muscle wasting during aging or catabolic states. It has been hypothesized that the digestion of whey may be too rapid during a catabolic situation to sustain the anabolic postprandial amino acid requirement necessary to elicit an optimal anabolic response. Interestingly, it has been shown recently that the duration of the postprandial stimulation of muscle protein synthesis in healthy conditions can be prolonged by the supplementary ingestion of a desynchronized carbohydrate load after food intake. We verified this hypothesis in the present study in two different cases of muscle wasting associated with anabolic resistance, i.e., glucocorticoid treatment and aging.

METHODS

Multi-catheterized minipigs were treated or not with glucocorticoids for 8 days. Muscle protein synthesis was measured sequentially over time after the infusion of a 13C phenylalanine tracer using the arterio-venous method before and after whey protein meal ingestion. The energy bolus was given 150 min after the meal. For the aging study, aged rats were fed the whey meal and muscle protein synthesis was measured sequentially over time with the flooding dose method using 13C Valine. The energy bolus was given 210 min after the meal.

RESULTS

Glucocorticoid treatment resulted in a decrease in the duration of the stimulation of muscle protein synthesis. The energy bolus given after food intake was unable to prolong this stimulation despite a simultaneous increase of insulin and glucose following its absorption. In old rats, a similar observation was made with no effect of the energy bolus on the duration of the muscle anabolic response following whey protein meal intake.

CONCLUSIONS

Despite very promising observations in healthy situations, the strategy aimed at increasing muscle protein synthesis stimulation by giving an energy bolus during the postprandial period remained inefficient in our two anabolic resistance models.

Post-ruminal branched-chain amino acid supplementation and intravenous lipopolysaccharide infusion alter blood metabolites, rumen fermentation, and nitrogen balance of beef steers

Steers exposed to an endotoxin may require additional branched-chain AA (BCAA) to support an increase in synthesis of immune proteins. This study evaluated effects of bacterial lipopolysaccharide (LPS) and BCAA supplementation on blood metabolites and N balance of 20 ruminally-cannulated steers (177 ± 4.2 kg BW). The experiment was a randomized block design, with 14-d adaptation to metabolism stalls and diet (DM fed = 1.5% BW) and 6-d collection. Treatments were a 2 × 2 factorial of LPS (0 vs. 1.0 to 1.5 μg/kg BW; -LPS vs. +LPS) and BCAA (0 vs. 35 g/d; -BCAA vs. +BCAA). The LPS in 100 mL sterile saline was infused (1 mL/min via i.v. catheter) on day 15. The BCAA in an essential AA solution were abomasally infused (900 mL/d) three times daily in equal portions beginning on day 7. Blood, rumen fluid, and rectal temperature were collected on day 15 at h 0, 2, 4, 8, 12, and 24 after LPS infusion. Feces and urine were collected from day 16 to 20. Rectal temperatures were greater for +LPS vs. -LPS steers at 4 h and lower at 8 h after LPS infusion (LPS × h, P < 0.01). Serum cortisol and plasma urea N were greater for +LPS than -LPS steers at 2 (cortisol only), 4, 8, 12, and 24 h after LPS infusion (LPS × h, P < 0.01). Serum cortisol was greater for +BCAA than -BCAA steers at 12 h after LPS infusion (BCAA × h, P < 0.05). Serum glucose was greater for +LPS than -LPS steers at 2 h after LPS infusion (LPS × h, P < 0.01). Plasma Ile, Leu, and Val were lower, and plasma His was greater in +LPS than -LPS steers (LPS, P < 0.05). Plasma Lys, Met, Thr, and Trp of +LPS steers were lower than -LPS steers at 4 (Thr only), 8 (Lys and Trp only), 12, and 24 h after infusion (LPS × h, P < 0.05). Plasma Ile, Leu, and Val were greater (BCAA, P < 0.01), and Met, His, Phe, Thr, and Trp were lower for +BCAA than -BCAA steers at 0 and 24 h after LPS infusion (BCAA × h, P ≤ 0.05). Steers receiving +LPS had lower rumen pH at 8 h, greater total VFA at 8 h, and lower rumen NH3 at 24 h after LPS infusion compared with -LPS steers (LPS × h, P ≤ 0.04). Total tract passage rates, DM, OM, NDF, ADF, and N intake, fecal N, digested N, and retained N were lower (P < 0.05) for +LPS than -LPS steers. Total N supply (dietary plus infused) and fecal N were greater (P < 0.05) for +BCAA vs. -BCAA steers. The absence of LPS × BCAA interactions (P ≥ 0.20) for N balance indicated that post-ruminal supplementation of BCAA did not alleviate the negative effects of endotoxin on N utilization by growing steers.

Effects of Parenteral Amino Acid Administration on the Postoperative Nutritional Status and Wound Healing of Protein-Malnourished Rats

In Japan, parenteral nutrition (PN) solutions are frequently administered to patients in the postoperative short-term period. In these cases, amino acid-containing peripheral parenteral nutrition (PPN) solutions, amino acid-free maintenance solutions or combinations of the two are used. However, consensus regarding the most beneficial solution for these patients is lacking. Here, we examined the nutritional status and wound healing outcomes in protein-malnourished rats receiving postoperative administrations of PPN solution, maintenance solution or combinations of the two solutions. Protein malnutrition was induced in Sprague-Dawley rats by feeding an AIN-93G-based low-protein diet (5% casein) for 2 wk. After laparotomy, dorsal skin incision, and placement of a jugular vein catheter, the rats were divided into 3 groups. Each group was administered 113 kcal/kg/d, with group A receiving maintenance solutions without amino acid, group B receiving PPN with 1.5% amino acid, and group C receiving PPN with 3% amino acid. After 5 d post-operative administration, we measured the tensile strength of the wound area, skeletal muscle weights, and nutritional parameters. Significantly higher plasma nutritional parameters and gastrocnemius and extensor digitorum longus (EDL) muscle weights were observed in groups B and C than in group A. Group C exhibited significantly elevated tensile strength of the wound area along with up-regulation of type I collagen mRNA expression compared to group A. These findings demonstrate the nutritional status and wound healing benefits of short-term postoperative administration of PPN solutions containing amino acids in protein-malnourished rats.

Metabolomic Assessment of Acute Cholestatic Injuries Induced by Thioacetamide and by Bile Duct Ligation, and the Protective Effects of Huang-Lian-Jie-Du-Decoction

Huang-Lian-Jie-Du-Decoction, a traditional Chinese formula, has been reported to protect liver from various injuries. Two cholestasis models of rats induced by thioacetamide and by bile duct ligation were established and treated with Huang-Lian-Jie-Du-Decoction. Nuclear Magnetic Resonance-based urinary metabolic profiles were analyzed by orthogonal partial least squares discriminant analysis and univariate analysis to excavate differential metabolites associated with the injuries of the two models and the treatment effects of Huang-Lian-Jie-Du-Decoction. The two cholestatic models shared common metabolic features of excessive fatty acid oxidation, insufficient glutathione regeneration and disturbed gut flora, with specific characteristics of inhibited urea cycle and DNA damage in thioacetamide-intoxicated model, and perturbed Kreb's cycle and inhibited branched chain amino acid oxidation in bile duct ligation model. With good treatment effects, Huang-Lian-Jie-Du-Decoction could regain the balance of the disturbed metabolic status common in the two cholestasis injuries, e.g., unbalanced redox system and disturbed gut flora; and perturbed urea cycle in thioacetamide-intoxicated model and energy crisis (disturbed Kreb's cycle and oxidation of branched chain amino acid) in bile duct ligation model, respectively.

Branched-chain amino acids in health and disease: metabolism, alterations in blood plasma, and as supplements

Branched-chain amino acids (BCAAs; valine, leucine, and isoleucine) are essential amino acids with protein anabolic properties, which have been studied in a number of muscle wasting disorders for more than 50 years. However, until today, there is no consensus regarding their therapeutic effectiveness.

In the article is demonstrated that the crucial roles in BCAA metabolism play: (i) skeletal muscle as the initial site of BCAA catabolism accompanied with the release of alanine and glutamine to the blood; (ii) activity of branched-chain keto acid dehydrogenase (BCKD); and (iii) amination of branched-chain keto acids (BCKAs) to BCAAs. Enhanced consumption of BCAA for ammonia detoxification to glutamine in muscles is the cause of decreased BCAA levels in liver cirrhosis and urea cycle disorders. Increased BCKD activity is responsible for enhanced oxidation of BCAA in chronic renal failure, trauma, burn, sepsis, cancer, phenylbutyrate-treated subjects, and during exercise. Decreased BCKD activity is the main cause of increased BCAA levels and BCKAs in maple syrup urine disease, and plays a role in increased BCAA levels in diabetes type 2 and obesity. Increased BCAA concentrations during brief starvation and type 1 diabetes are explained by amination of BCKAs in visceral tissues and decreased uptake of BCAA by muscles.

The studies indicate beneficial effects of BCAAs and BCKAs in therapy of chronic renal failure. New therapeutic strategies should be developed to enhance effectiveness and avoid adverse effects of BCAA on ammonia production in subjects with liver cirrhosis and urea cycle disorders. Further studies are needed to elucidate the effects of BCAA supplementation in burn, trauma, sepsis, cancer and exercise. Whether increased BCAA levels only markers are or also contribute to insulin resistance should be known before the decision is taken regarding their suitability in obese subjects and patients with type 2 diabetes.

It is concluded that alterations in BCAA metabolism have been found common in a number of disease states and careful studies are needed to elucidate their therapeutic effectiveness in most indications.

Amino acid kinetics and the response to nutrition in patients with cancer

PURPOSE

Amino acids are involved in many physiological processes in the body and serve as building blocks of proteins which are the main component of muscle mass. Often patients with cancer experience muscle wasting, which is associated with poor outcomes. The purpose of this paper is to discuss amino acid kinetics in cancer, review the evidence on the response to nutrition in patients with cancer, and to give recommendations on the appropriate level of amino acid or protein intake in cancer. Current evidence shows that amino acid kinetics in patients with cancer are disturbed, as reflected by increased and decreased levels of plasma amino acids, an increased whole body turnover of protein and muscle protein breakdown. A few studies show beneficial effects of acute and short-term supplementation of high protein meals or essential amino acid mixtures on muscle protein synthesis.

CONCLUSIONS

Cancer is associated with disturbances in amino acid kinetics. A high protein intake or supplementation of amino acids may improve muscle protein synthesis. Future research needs to identify the optimal level and amino acid mixtures for patients with cancer, in particular for those who are malnourished.

At same leucine intake, a whey/plant protein blend is not as effective as whey to initiate a transient post prandial muscle anabolic response during a catabolic state in mini pigs

BACKGROUND

Muscle atrophy has been explained by an anabolic resistance following food intake and an increase of dietary protein intake is recommended. To be optimal, a dietary protein has to be effective not only to initiate but also to prolong a muscle anabolic response in a catabolic state. To our knowledge, whether or not a dairy or a dairy/plant protein blend fulfills these criterions is unknown in a muscle wasting situation.

OBJECTIVE

Our aim was, in a control and a catabolic state, to measure continuously muscle anabolism in term of intensity and duration in response to a meal containing casein (CAS), whey (WHEY) or a whey/ plant protein blend (BLEND) and to evaluate the best protein source to elicit the best post prandial anabolism according to the physio-pathological state.

METHODS

Adult male Yucatan mini pigs were infused with U-13C-Phenylalanine and fed either CAS, WHEY or BLEND. A catabolic state was induced by a glucocorticoid treatment for 8 days (DEX). Muscle protein synthesis, proteolysis and balance were measured with the hind limb arterio-venous differences technique. Repeated time variance analysis were used to assess significant differences.

RESULTS

In a catabolic situation, whey proteins were able to initiate muscle anabolism which remained transient in contrast to the stimulated muscle protein accretion with WHEY, CAS or BLEND in healthy conditions. Despite the same leucine intake compared to WHEY, BLEND did not restore a positive protein balance in DEX animals.

CONCLUSIONS

Even with WHEY, the duration of the anabolic response was not optimal and has to be improved in a catabolic state. The use of BLEND remained of lower efficiency even at same leucine intake than whey.

An exploratory study on the efficacy and safety of a BCAA preparation used in combination with cardiac rehabilitation for patients with chronic heart failure

Background

Sarcopenia is generally complicated with patients with chronic heart failure (CHF) and its presence negatively affects the course of heart failure, however effective nutritional intervention had not been elucidated yet. The primary objective of this study is to explore whether the addition of a branched-chain amino acid (BCAA) preparation for cardiac rehabilitation (CR) of patients with CHF further improves cardiopulmonary functions, skeletal muscle functions, and metabolism in comparison with conventional CR.

Methods

This is a randomized, parallel-group comparative study. The elderly patients that were participated in CR and complicated with left ventricular systolic or diastolic dysfunction are randomized into two groups, CR + BCAA and CR. 20 weeks later, the second randomization is performed, which divide subjects into two groups with and without BCAA intervention without CR. Primary outcome measure is the rate of change of the anaerobic threshold workload from baseline to post-intervention. Secondary outcome include parameters of exercise capacity, cardiac function and psychological status.

Discussion

In the current study the effect of a promising new intervention, BCAA, will be assessed to determine whether its addition to CR improve exercise capacity in patients with heart failure, who are generally complicated with sarcopenia.

Trial registration

This clinical trial was registered with the University Hospital Medical Information Network—Clinical Trials Registry (UMIN–CTR; JPRN–UMIN R000022440).

Metabolomic analysis based on 1H-nuclear magnetic resonance spectroscopy metabolic profiles in tuberculous, malignant and transudative pleural effusion

Pleural effusion is a common clinical manifestation with various causes. Current diagnostic and therapeutic methods have exhibited numerous limitations. By involving the analysis of dynamic changes in low molecular weight catabolites, metabolomics has been widely applied in various types of disease and have provided platforms to distinguish many novel biomarkers. However, to the best of our knowledge, there are few studies regarding the metabolic profiling for pleural effusion. In the current study, 58 pleural effusion samples were collected, among which 20 were malignant pleural effusions, 20 were tuberculous pleural effusions and 18 were transudative pleural effusions. The small molecule metabolite spectrums were obtained by adopting ¹H nuclear magnetic resonance technology, and pattern-recognition multi-variable statistical analysis was used to screen out different metabolites. One-way analysis of variance, and Student-Newman-Keuls and the Kruskal-Wallis test were adopted for statistical analysis. Over 400 metabolites were identified in the untargeted metabolomic analysis and 26 metabolites were identified as significantly different among tuberculous, malignant and transudative pleural effusions. These metabolites were predominantly involved in the metabolic pathways of amino acids metabolism, glycometabolism and lipid metabolism. Statistical analysis revealed that eight metabolites contributed to the distinction between the three groups: Tuberculous, malignant and transudative pleural effusion. In the current study, the feasibility of identifying small molecule biochemical profiles in different types of pleural effusion were investigated reveal novel biological insights into the underlying mechanisms. The results provide specific insights into the biology of tubercular, malignant and transudative pleural effusion and may offer novel strategies for the diagnosis and therapy of associated diseases, including tuberculosis, advanced lung cancer and congestive heart failure.

Effects of branched-chain amino acids (BCAAs) on the progression of advanced liver disease: A Korean nationwide, multicenter, retrospective, observational, cohort study

Evidence of the potential benefits of long-term oral branched-chain amino acid (BCAA) supplementation in reducing the severity of liver disease is limited.Patients who were diagnosed with liver cirrhosis with a Child-Pugh (CP) score of 8-10 were included. The BCAA group consumed BCAAs daily for at least 6 months, and the control group consumed a diet without BCAA. We analyzed the improvements based on the model for end-stage liver disease (MELD) score, CP score, incidence of cirrhosis-related complications, and event-free survival over 2 years. Among the 867 recruited patients, 307 (166 in the BCAA group and 141 in the control group) were analyzed. The BCAA group was divided into 3 subgroups, whose patients consumed 4.15 g, 8.3 g, or 12.45 g of BCAAs daily for the analysis. There were significant differences in the CP score, albumin, and hepatic encephalopathy between the 2 groups at baseline. After matching the propensity scores, we analyzed patients in the BCAA-12.45 g group (12.45 g of BCAAs daily, n = 41) and matched control group (n = 41). The MELD score significantly improved in the BCCA-12.45 g group compared to the matched control group (P = .004). The changes in the serum bilirubin level (P = .014) and CP score (P = .033) over time also differed significantly between the 2 groups. The incidence rates of cirrhosis-related complications (P = .973) and development of hepatocellular carcinoma (2 cases each) did not differ significantly between the 2 groups.Long-term oral BCAA supplementation has beneficial effects in patients with advanced liver cirrhosis. A further large-scale prospective study is needed to delineate these beneficial effects.

Protein Turnover and Metabolism in the Elderly Intensive Care Unit Patient

Many intensive care unit (ICU) patients do not achieve target protein intakes particularly in the early days following admittance. This period of iatrogenic protein undernutrition contributes to a rapid loss of lean, in particular muscle, mass in the ICU. The loss of muscle in older (aged >60 years) patients in the ICU may be particularly rapid due to a perfect storm of increased catabolic factors, including systemic inflammation, disuse, protein malnutrition, and reduced anabolic stimuli. This loss of muscle mass has marked consequences. It is likely that the older patient is already experiencing muscle loss due to sarcopenia; however, the period of stay in the ICU represents a greatly accelerated period of muscle loss. Thus, on discharge, the older ICU patient is now on a steeper downward trajectory of muscle loss, more likely to have ICU-acquired muscle weakness, and at risk of becoming sarcopenic and/or frail. One practice that has been shown to have benefit during ICU stays is early ambulation and physical therapy (PT), and it is likely that both are potent stimuli to induce a sensitivity of protein anabolism. Thus, recommendations for the older ICU patient would be provision of at least 1.2-1.5 g protein/kg usual body weight/d, regular and early utilization of ambulation (if possible) and/or PT, and follow-up rehabilitation for the older discharged ICU patient that includes rehabilitation, physical activity, and higher habitual dietary protein to change the trajectory of ICU-mediated muscle mass loss and weakness.

Leucine and Mammalian Target of Rapamycin-Dependent Activation of Muscle Protein Synthesis in Aging

The preservation or restoration of muscle mass is of prime importance for healthy aging. However, aging has been repeatedly shown to be associated with resistance of muscle to the anabolic effects of feeding. Leucine supplementation has been proposed as a possible strategy because of its regulatory role on protein homeostasis. Indeed, it acts independently of growth factors and leads to enhanced cap-dependent mRNA translation initiation and increased protein synthesis. Leucine acts as a signaling molecule directly at the muscle level via the activation of mammalian/mechanistic target of rapamycin complex 1 (mTORC1). However, in aged muscle, mTORC1 activation seems to be impaired, with decreased sensitivity and responsiveness of muscle protein synthesis to amino acids, whereas the phosphorylation state of several components of this signaling pathway appears to be higher in the basal state. This may stem from specific age-related impairment of muscle signaling and from decreased nutrient and growth factor delivery to the muscle. Whether aging per se affects mTORC1 signaling remains to be established, because aging is frequently associated with inadequate protein intake, decreased insulin sensitivity, inactivity, inflammatory processes, etc. Whatever its origin, this anabolic resistance to feeding can be mitigated by quantitative and qualitative manipulation of protein supply, such as leucine supplementation; however, there remains the question of possible adverse effects of long-term, high-dose leucine supplementation in terms of insulin resistance and tumorigenesis.

Metformin treatment modulates the tumour-induced wasting effects in muscle protein metabolism minimising the cachexia in tumour-bearing rats

Background

Cancer-cachexia state frequently induces both fat and protein wasting, leading to death. In this way, the knowledge of the mechanism of drugs and their side effects can be a new feature to treat and to have success, contributing to a better life quality for these patients. Metformin is an oral drug used in type 2 diabetes mellitus, showing inhibitory effect on proliferation in some neoplastic cells. For this reason, we evaluated its modulatory effect on Walker-256 tumour evolution and also on protein metabolism in gastrocnemius muscle and body composition.

Methods

Wistar rats received or not tumour implant and metformin treatment and were distributed into four groups, as followed: control (C), Walker 256 tumour-bearing (W), metformin-treated (M) and tumour-bearing treated with metformin (WM). Animals were weighed three times a week, and after cachexia state has been detected, the rats were euthanised and muscle and tumour excised and analysed by biochemical and molecular assays.

Results

Tumour growth promoted some deleterious effects on chemical body composition, increasing water and decreasing fat percentage, and reducing lean body mass. In muscle tissue, tumour led to a decreased protein synthesis and an increased proteolysis, showing the higher activity of the ubiquitin-proteasome pathway. On the other hand, the metformin treatment likely minimised the tumour-induced wasting state; in this way, this treatment ameliorated chemical body composition, reduced the higher activities of proteolytic enzymes and decreased the protein waste.

Conclusion

Metformin treatment not only decreases the tumour growth but also improves the protein metabolism in gastrocnemius muscle in tumour-bearing rats.

Glutamine metabolism in advanced age

Glutamine, reviewed extensively in the last century, is a key substrate for the splanchnic bed in the whole body and is a nutrient of particular interest in gastrointestinal research. A marked decrease in the plasma glutamine concentration has recently been observed in neonates and adults during acute illness and stress. Although some studies in newborns have shown parenteral and enteral supplementation with glutamine to be of benefit (by decreasing proteolysis and activating the immune system), clinical trials have not demonstrated prolonged advantages such as reductions in mortality or risk of infections in adults. In addition, glutamine is not able to combat the muscle wasting associated with disease or age-related sarcopenia. Oral glutamine supplementation initiated before advanced age in rats increases gut mass and improves the villus height of mucosa, thereby preventing the gut atrophy encountered in advanced age. Enterocytes from very old rats continuously metabolize glutamine into citrulline, which allowed, for the first time, the use of citrulline as a noninvasive marker of intestinal atrophy induced by advanced age.

Walker 256 tumor-bearing rats demonstrate altered interstitial cells of Cajal. Effects on ICC in the Walker 256 tumor model

BACKGROUND

Cachexia is a significant problem in patients with cancer. The effect of cancer on interstitial cells of Cajal (ICC) and neurons of the gastrointestinal tract have not been studied previously. Although supplementation with L-glutamine 2% may have beneficial effects in cancer-related cachexia, and be protective of ICC in models of oxidative stress such as diabetes, its effects on ICC in cancer have also not been studied.

METHODS

Twenty-eight male Wistar rats were divided into four groups: control (C), control supplemented with L-glutamine (CG), Walker 256 tumor (WT), and Walker 256 tumor supplemented with L-glutamine (WTG). Rats were implanted with tumor cells or injected with saline in the right flank. After 14 days, the jejunal tissues were collected and processed for immunohistochemical techniques including whole mounts and cryosections and Western blot analysis.

KEY RESULTS

Tumor-bearing rats demonstrate reduced numbers of Myenteric ICC and deep muscular plexus ICC and yet increased Ano1 protein expression and enhanced ICC networks. In addition, there is more nNOS protein expressed in tumor-bearing rats compared to controls. L-glutamine treatment had a variety of effects on ICC that may be related to the disease state and the interaction of ICC and nNOS neurons. Regardless, L-glutamine reduced the size of tumors and also tumor-induced cachexia that was not due to altered food intake.

CONCLUSIONS & INFERENCES

There are significant effects on ICC in the Walker 256 tumor model. Although supplementation with L-glutamine has differential and complex effects of ICC, it reduces tumor size and tumor-associated cachexia, which supports its beneficial therapeutic role in cancer.

L-Leucine for gold nanoparticles synthesis and their cytotoxic effects evaluation

This work reports the preparation of water-soluble leucine capped gold nanoparticles by two single-step synthesis methods. The first procedure involves a citrate reduction approach where the citrate is used as reducing agent and leucine as capping/stabilizing agent. Different sizes of gold nanoparticles, citrate reduced and stabilized by leucine, Leu-AuNPs-C, with the mean diameters in the range of 21-56 nm, were obtained by varying the macroscopic parameters such as: concentration of the gold precursor solution, Au (III):citrate molar ratio and leucine pH. In the second procedure, leucine acts both as reducing and stabilizing agent, allowing us to obtain spherical gold nanoparticles, Leu-AuNPs, with a majority of 80 % (with the mean diameter of 63 nm). This proves that leucine is an appropriate reductant for the formation of water-soluble and stable gold nanoparticles colloids. The characterization of the leucine coated gold nanoparticles was carried out by TEM, UV-Vis and FT-IR analysis. The cytotoxic effect of Leu-AuNPs-C and Leu-AuNPs was also evaluated.

Perioperative nutritional support and fluid therapy in patients with liver diseases

The prevalence of liver dysfunction and malnutrition is common among patients with obstructive jaundice or cirrhosis, the poor nutrition status in patients with indications for hepatic resection increases the risk of postoperative complications and/or mortality. Hepatic surgery significantly affects body's metabolism and environment. Therefore, it is very important for patients with liver diseases undergoing hepatic surgery to receive essential nutritional support and fluid therapy during perioperative period. There are several principles in nutritional support and fluid therapy that surgeons need to pay attention to, for example, time, nutritional approach, fluid volume, choice of fat emulsions and amino acids. Some issues, such as albumin and plasma application, choice of crystalloid and colloid, liver protective therapy, also need further attention.

An overview of amines as nutritional supplements to counteract cancer cachexia

Cancer cachexia is a complex multifactorial syndrome characterized by loss of skeletal muscle mass (with or without loss of fat mass) that cannot be fully reversed by conventional nutritional support and leads to progressive functional impairment. Recently, some amino acids and other amine dietary supplements have been highlighted in medical field due to positive effects upon diseases evolving skeletal muscle atrophy. Therefore, the aim of this brief review is to discuss the putative application of amines as dietary supplements to counteract skeletal muscle wasting on cancer cachexia. Specifically, we focus in two nutritional supplements: (1) branched-chain amino acids (BCAAs) and (2) creatine. Both BCAAs and creatine may attenuate proteolysis and enhance proteins synthesis in skeletal muscle. Although more experimental studies and clinical trials are still necessary to elucidate this therapeutic application, several evidences have demonstrated that amines supplementation is a promising coadjuvant treatment to cancer cachexia.

Leucine-rich diet supplementation modulates foetal muscle protein metabolism impaired by Walker-256 tumour

BACKGROUND

Cancer-cachexia induces a variety of metabolic disorders of protein turnover and is more pronounced when associated with pregnancy. Tumour-bearing pregnant rats have impaired protein balance, which decreases protein synthesis and increases muscle breakdown. Because branched-chain amino acids, especially leucine, stimulate protein synthesis, we investigated the effect of a leucine-rich diet on protein metabolism in the foetal gastrocnemius muscles of tumour-bearing pregnant rats.

METHODS

Foetuses of pregnant rats with or without Walker 256 tumours were divided into six groups. During the 20 days of the experiment, the pregnant groups were fed with either a control diet (C, control rats; W, tumour-bearing rats; Cp, rats pair-fed the same normoprotein-diet as the W group) or with a leucine-rich diet (L, leucine rats; LW, leucine tumour-bearing rats; and Lp, rats pair-fed the same leucine-rich diet as the LW group). After the mothers were sacrificed, the foetal gastrocnemius muscle samples were resected, and the protein synthesis and degradation and tissue chymotrypsin-like, cathepsin and calpain enzyme activities were assayed. The muscle oxidative enzymes (catalase, glutathione-S-transferase and superoxide dismutase), alkaline phosphatase enzyme activities and lipid peroxidation (malondialdehyde) were also measured.

RESULTS

Tumour growth led to a reduction in foetal weight associated with decreased serum protein, albumin and glucose levels and low haematocrit in the foetuses of the W group, whereas in the LW foetuses, these changes were less pronounced. Muscle protein synthesis (measured by L-[3H]-phenylalanine incorporation) was reduced in the W foetuses but was restored in the LW group. Protein breakdown (as assessed by tyrosine release) was enhanced in the L and W groups, but chymotrypsin-like activity increased only in group W and tended toward an increase in the LW foetuses. The activity of cathepsin H was significantly higher in the W group foetuses, but the proteolytic calcium-dependent pathway showed similar enzyme activity. In parallel, an intense oxidative stress process was observed only in the group W foetuses.

CONCLUSIONS

These data suggested that the proteasomal and lysosomal proteolytic pathways and oxidative stress are likely to participate in the process of foetal muscle catabolism of Walker's tumour-bearing pregnant rats. The present work shows that foetal muscle can be protected by supplementation with a leucine-rich diet.

Cancer cachexia and diabetes: similarities in metabolic alterations and possible treatment

Cancer cachexia is a metabolic syndrome featuring many alterations typical of type 2 diabetes (T2D). While muscle wasting is a hallmark of cachexia, epidemiological evidence also supports an accelerated age-related muscle loss in T2D. Insulin resistance manifests in both conditions and impairs glucose disposal and protein anabolism by tissues. A greater contribution of gluconeogenesis to glucose production may limit amino acid availability for muscle protein synthesis, further aggravating muscle loss. In the context of inter-dependence between glucose and protein metabolism, the present review summarizes the current state of knowledge on alterations that may lead to muscle wasting in human cancer. By highlighting the similarities with T2D, a disease that has been more extensively studied, the objective of this review is to provide a better understanding of the pathophysiology of cancer cachexia and to consider potential treatments usually targeted for T2D. Nutritional approaches aimed at stimulating protein anabolism might include specially formulated food with optimal protein and amino acid composition. Because the gradual muscle loss in T2D may be attenuated by diabetes treatment, anti-diabetic drugs might be considered in cachexia treatment. Metformin emerges as a choice candidate as it acts both on reducing gluconeogenesis and improving insulin sensitivity, and has demonstrated tumour suppressor properties in multiple cancer types. Such a multimodal approach to slow or reverse muscle wasting in cachexia warrants further investigation.

Cancer usurps skeletal muscle as an energy repository

Cancer cells produce energy through aerobic glycolysis, but contributions of host tissues to cancer energy metabolism are unclear. In this study, we aimed to elucidate the cancer-host energy production relationship, in particular, between cancer energy production and host muscle. During the development and progression of colorectal cancer, expression of the secreted autophagy-inducing stress protein HMGB1 increased in the muscle of tumor-bearing animals. This effect was associated with decreased expression of pyruvate kinase PKM1 and pyruvate kinase activity in muscle via the HMGB1 receptor for advanced glycation endproducts (RAGE). However, muscle mitochondrial energy production was maintained. In contrast, HMGB1 addition to colorectal cancer cells increased lactate fermentation. In the muscle, HMGB1 addition induced autophagy by decreasing levels of active mTOR and increasing autophagy-associated proteins, plasma glutamate, and (13)C-glutamine incorporation into acetyl-CoA. In a mouse model of colon carcinogenesis, a temporal increase in HMGB1 occurred in serum and colonic mucosa with an increase in autophagy associated with altered plasma free amino acid levels, increased glutamine, and decreased PKM1 levels. These differences were abolished by administration of an HMGB1 neutralizing antibody. Similar results were obtained in a mouse xenograft model of human colorectal cancer. Taken together, our findings suggest that HMGB1 released during tumorigenesis recruits muscle to supply glutamine to cancer cells as an energy source.

Multidisciplinary team-based approach for comprehensive preoperative pulmonary rehabilitation including intensive nutritional support for lung cancer patients

Background

To decrease the risk of postoperative complication, improving general and pulmonary conditioning preoperatively should be considered essential for patients scheduled to undergo lung surgery.

Objective

The aim of this study is to develop a short-term beneficial program of preoperative pulmonary rehabilitation for lung cancer patients.

Methods

From June 2009, comprehensive preoperative pulmonary rehabilitation (CHPR) including intensive nutritional support was performed prospectively using a multidisciplinary team-based approach. Postoperative complication rate and the transitions of pulmonary function in CHPR were compared with historical data of conventional preoperative pulmonary rehabilitation (CVPR) conducted since June 2006. The study population was limited to patients who underwent standard lobectomy.

Results

Postoperative complication rate in the CVPR (n = 29) and CHPR (n = 21) were 48.3% and 28.6% (p = 0.2428), respectively. Those in patients with Charlson Comorbidity Index scores ≥2 were 68.8% (n = 16) and 27.3% (n = 11), respectively (p = 0.0341) and those in patients with preoperative risk score in Estimation of Physiologic Ability and Surgical Stress scores >0.3 were 57.9% (n = 19) and 21.4% (n = 14), respectively (p = 0.0362). Vital capacities of pre- and post intervention before surgery in the CHPR group were 2.63±0.65 L and 2.75±0.63 L (p = 0.0043), respectively; however, their transition in the CVPR group was not statistically significant (p = 0.6815). Forced expiratory volumes in one second of pre- and post intervention before surgery in the CHPR group were 1.73±0.46 L and 1.87±0.46 L (p = 0.0012), respectively; however, their transition in the CVPR group was not statistically significant (p = 0.6424).

Conclusions

CHPR appeared to be a beneficial and effective short-term preoperative rehabilitation protocol, especially in patients with poor preoperative conditions.

NMR-based metabolomic analysis of human bladder cancer

Bladder cancer (BC) is one of the most common cancers and has a high mortality rate. However, both metabolite variations and metabolic pathways related to the pathogenic process of BC remain to be addressed, such results might contribute to early detection of the disease. (1)H nuclear magnetic resonance (NMR)-based metabolomics was applied to identify differences of serum metabolic profiles among BC, calculi patients and healthy subjects. Serum metabolic profiles of BC patients are distinctly different from those of calculi and healthy subjects. Compared with those from healthy subjects, serum samples from BC patients show decreased levels of isoleucine/leucine, tyrosine, lactate, glycine, citrate, as well as increased levels of lipids and glucose. The results reveal disturbed metabolic pathways of aromatic amino acids, glycolysis and citrate cycle, as well as lipogenesis metabolism in BC patients. Our work will be of potential benefit to understanding the pathogenic process of BC and will offer valuable information for noninvasive diagnosis of the disease.

Nutrition support and infections associated with hepatic resection and liver transplantation in patients with chronic liver disease

Malnutrition is common in liver cirrhotic patients who will undergo liver resection or liver transplantation. A precise evaluation of their nutrition status is thus difficult because of the presence of ascites and the edema caused by their impaired protein synthesis. Both perioperative enteral and parenteral nutrition have benefits in reducing the morbidity and mortality of liver surgery, and in general, oral nutrition supplements are recommended. Branched-chain amino acids (BCAAs) promote protein and glycogen synthesis and regulate immune system function. Synbiotics, a combination of pro- and prebiotics, is reported to enhance immune responses. Oral nutrition support with BCAAs, synbiotics, and an immune-enhancing diet have a beneficial effect on preventing the perioperative infections associated with hepatic resection or liver transplantation.

Metabonomic analysis of the therapeutic effect of Zhibai Dihuang Pill in treatment of streptozotocin-induced diabetic nephropathy

ETHNOPHARMACOLOGICAL RELEVANCE

Zhibai Dihuang Pill (ZDP) is one of ancient traditional Chinese medicines (TCMs), which is usually used for the treatment of kidney deficiency for thousands of years in China.

AIM OF THE STUDY

Traditional Chinese medicines (TCMs) usually operate in vivo through multi-components, multi-ways and multi-targets. However, the molecular mechanisms of TCMs remain unclear. In the present work, nuclear magnetic resonance (NMR)-based metabonomic analysis was used to evaluate the therapeutic effect of Zhibai Dihuang Pill (ZDP) on diabetic nephropathy (DN) rats induced by streptozotocin and to address the underlying molecular mechanism.

MATERIALS AND METHODS

Male rats were divided into three groups: control, DN and ZDP-treated DN (ZDP-DN), respectively. Based on (1)H NMR spectra of sera, urine and kidney extracts from the rats, principle component analysis (PCA) was performed to identify different metabolic profiles. Kidney portions and serum and urine samples were also subjected to histopathological or biochemical examination.

RESULTS

PCA scores plots demonstrate that the cluster of DN rats is separated from that of control rats, while some of ZDP-DN rats are located close to control rats, indicating that metabolic profiles of these ZDP-DN rats are restored toward those of control rats. Our results illustrate that ZDP treatment could lower the levels of lipids and 3-hydrobutyrate, and raise the level of lactate in sera of DN rats. Moreover, ZDP treatment could also reduce the levels of glucose, 3-hydrobutyrate and lactate, enhance the level of betaine in kidney tissues.

CONCLUSION

Our study indicates that ZDP treatment can ameliorate DN symptoms by intervening in some dominating metabolic pathways, such as inhibiting glucose and lipid metabolism, enhancing methylamine metabolism. Our work may be of benefit to both evaluation of the therapeutic effect of TCM and elucidation of the underlying molecular mechanism.