Anserine

Duck-egg white hydrolysate supplementation enhances muscle endurance and fatigue resistance during high-intensity exercise.

Kai-Li Shang, Yi-Ling Lin, Christoper Caesar Yudho Sutopo +2 more

Recent processing advances, including separating and marinating duck yolks, provide alternatives to traditional salted duck eggs. However, separated duck-egg white remains a nutritious agricultural byproduct due to its unpleasant odor and low consumer acceptance. Duck-egg white hydrolysates (DEWHs), produced by protease-A hydrolysis, are rich in branched-chain amino acids (BCAAs) and imidazole dipeptides like carnosine and anserine. In mice undergoing high-intensity exercise, DEWH supplementation increased hindlimb muscle mass, soleus-muscle-fiber size, and performance in swimming and treadmill tests. DEWHs improved lactate clearance, stabilized post-exercise blood glucose, and elevated muscle and liver glycogen (p < 0.05). DEWHs also improved exercise-induced muscle injury markers (AST, BUN, and CK) and inflammatory cytokines (IL-1β, IL-6, and TNF-α), and decreased antioxidant capacities (reduced GSH, SOD, and GSH-Px) (p < 0.05). In C2C12 myotubes, DEWHs counteracted dexamethasone (Dex)-induced mitochondrial dysfunction, suppressed protein synthesis, and ATP depletion while decreased protein synthesis signaling (p-p70S6K/p70S6K and p-4EBP1/4EBP1), and upregulated protein degradation markers (p-FoxO1/FoxO1 and TRIM63) and mitochondrial biogenesis factors (NRF1 and PGC-1α) were also mitigated (p < 0.05). Additionally, DEWHs enhanced citrate synthase and cytochrome c oxidase activities, boosting ATP production (p < 0.05). These findings suggest DEWHs enhance muscular endurance, reduce fatigue, and mitigate oxidative and inflammatory responses by modulating protein turnover and energy production, offering a novel protein supplement and value-added use for duck-egg white byproduct surplus.

Anserine, Balenine, and Ergothioneine: Impact of Histidine-Containing Compounds on Exercise Performance-A Narrative Review.

Maciej Jędrejko, Katarzyna Kała, Bożena Muszyńska

Histidine is an amino acid which plays a critical role in protein synthesis, muscle buffering during anaerobic exercise, and antioxidation. It also acts as a precursor to carnosine, a dipeptide that enhances physical performance by being present in fast-contracting muscle fibers and contributing to buffering capacity. Recent studies have examined other histidine-containing compounds, such as anserine, balenine, and ergothioneine, to assess their potential benefits for physical activity. This narrative review focuses on the literature about the effects of dietary supplementation with these histidine-containing compounds on exercise capacity in animals and humans. The findings indicate that anserine may improve physical performance and reduce fatigue, particularly in quick, repetitive activities. Although balenine has been less extensively studied, it has shown promise in enhancing muscle regeneration and antioxidative defense in animal models. Ergothioneine, a sulfur-containing histidine derivative, displayed antioxidant and anti-inflammatory properties in both animal and human studies, suggesting its potential role in reducing exercise-induced oxidative stress and aiding recovery. The diversity of the presented studies and their limitations do not provide an opportunity to confirm the ergogenic properties of the histidine-containing compounds studied. Nevertheless, supplementation with anserine and ergothioneine shows promise for enhancing physical performance and recovery, though further research is required to better understand their mechanisms and optimize their use in sports and exercise.

Carnosine synthase deficiency in mice affects protein metabolism in skeletal muscle.

Jiawei Wu, Ai Egusa, Toshihide Nishimura

Carnosine and anserine are abundant peptides found in the skeletal muscle and nervous system in many vertebrates. Several in vitro and in vivo studies have demonstrate that exogenously administered carnosine improves exercise performance. Furthermore, carnosine is an antioxidant and antifatigue supplement. However, the physiological functions of endogenous carnosine and its related histidine-containing dipeptides in a living organism remain unclear. We aimed to clarify the physiological roles of endogenous carnosine by investigating the characteristics of carnosine synthase gene-deficient mice and the effects of carnosine on skeletal muscle protein metabolism. We discovered that carnosine and anserine were undetectable in the skeletal muscle of carnosine synthase knockout mice. We also quantified protein gene expression and enzyme levels in muscle protein metabolism. Gene and protein levels of the muscle protein synthesizer insulin-like growth factor-1 (IGF-1) and the degrading enzyme cathepsin B were markedly lower in carnosine synthase gene-deficient mice than those in wild-type mice. The amount of 3-methylhistidine (a marker for muscle proteolysis) in forced exercise and the weight of the gastrocnemius muscle were considerably lower in carnosine synthase gene-deficient mice than in wild-type mice. Consequently, we showed that carnosine deficiency affects weight maintenance and protein metabolism in skeletal muscle, suggesting that carnosine regulates skeletal muscle protein metabolism.

Influence of Imidazole-Dipeptides on Cognitive Status and Preservation in Elders: A Narrative Review.

Nobutaka Masuoka, Chenxu Lei, Haowei Li +1 more

The worldwide increase in the number of patients with dementia is becoming a growing problem, while Alzheimer's disease (AD), a primary neurodegenerative disorder, accounts for more than 70% of all dementia cases. Research on the prevention or reduction of AD occurrence through food ingredients has been widely conducted. In particular, histidine-containing dipeptides, also known as imidazole dipeptides derived from meat, have received much attention. Imidazole dipeptides are abundant in meats such as poultry, fish, and pork. As evidenced by data from recent human intervention trials conducted worldwide, daily supplementation of carnosine and anserine, which are both imidazole dipeptides, can improve memory loss in the elderly and reduce the risk of developing AD. This article also summarizes the latest researches on the biochemical properties of imidazole dipeptides and their effects on animal models associated with age-related cognitive decline. In this review, we focus on the results of human intervention studies using supplements of poultry-derived imidazole dipeptides, including anserine and carnosine, affecting the preservation of cognitive function in the elderly, and discuss how imidazole dipeptides act in the brain to prevent age-related cognitive decline and the onset of dementia.

The Therapeutic Potential of Carnosine/Anserine Supplementation against Cognitive Decline: A Systematic Review with Meta-Analysis.

Giuseppe Caruso, Justyna Godos, Sabrina Castellano +6 more

Carnosine is a natural occurring endogenous dipeptide that was proposed as an anti-aging agent more than 20 years ago. Carnosine can be found at low millimolar concentrations at brain level and different preclinical studies have demonstrated its antioxidant, anti-inflammatory, and anti-aggregation activity with neuroprotective effects in animal models of Alzheimer's disease (AD). A selective deficit of carnosine has also been linked to cognitive decline in AD. Different clinical studies have been conducted to evaluate the impact of carnosine supplementation against cognitive decline in elderly and AD subjects. We conducted a systematic review with meta-analysis, in accordance with the PRISMA guidelines coupled to the PICOS approach, to investigate the therapeutic potential of carnosine against cognitive decline and depressive symptoms in elderly subjects. We found five studies matching the selection criteria. Carnosine/anserine was administered for 12 weeks at a dose of 1 g/day and improved global cognitive function, whereas no effects were detected on depressive symptoms. These data suggest a preliminary evidence of clinical efficacy of carnosine against cognitive decline both in elderly subjects and mild cognitive impairment (MCI) patients, although larger and long-term clinical studies are needed in MCI patients (with or without depression) to confirm the therapeutic potential of carnosine.

Comparative physiology investigations support a role for histidine-containing dipeptides in intracellular acid-base regulation of skeletal muscle.

Eimear Dolan, Bryan Saunders, Roger Charles Harris +4 more

Histidine containing dipeptides (HCDs: carnosine, anserine and balenine) have numerous therapeutic and ergogenic properties, but there is a lack of consensus on the mechanistic pathways through which they function. Potential roles include intracellular buffering, neutralisation of reactive species, and calcium regulation. Comparative investigations of the HCD content of various species provide unique insight into their most likely mechanisms of action. This review chronologically describes how the comparative physiology studies, conducted since the beginning of the 20th century, have shaped our understanding of the physiological roles of HCDs. The investigation of a wide range of physiologically distinct species indicates that those species with a strong reliance on non-oxidative forms of energy production are abundant in HCDs. These include: whales who experience long periods of hypoxia while diving; racehorses and greyhound dogs who have highly developed sprint abilities, and chickens and turkeys whose limited capacity for flight is largely fuelled by their white, glycolytic, muscle. Additionally, a higher HCD content in the Type 2 muscle fibres of various species (which have greater capacity for non-oxidative metabolism) was consistently observed. The pKa of the HCDs render them ideally suited to act as intracellular physicochemical buffers within the pH transit range of the skeletal muscle. As such, their abundance in species which show a greater reliance on non-oxidative forms of energy metabolism, and which experience regular challenges to acid-base homeostasis, provides strong evidence that intracellular proton buffering is an important function of the HCDs in skeletal muscle.

Anserine/Carnosine Supplementation Suppresses the Expression of the Inflammatory Chemokine CCL24 in Peripheral Blood Mononuclear Cells from Elderly People.

Yoshinori Katakura, Mamoru Totsuka, Etsuko Imabayashi +2 more

Our goal was to determine whether anserine/carnosine supplementation (ACS) suppresses chemokine levels in elderly people. In a double-blind randomized controlled trial, volunteers were assigned to the ACS or placebo group (1:1). Sixty healthy elderly volunteers (active, n = 30; placebo, n = 30) completed the study. The ACS group was administered 1.0 g of anserine/carnosine (3:1) for 3 months. A microarray analysis and subsequent quantitative real-time polymerase chain reaction (qRT-PCR) analysis of peripheral blood mononuclear cells (PBMCs) showed decreased expression of CCL24, an inflammatory chemokine (p < 0.05). Verbal memory, assessed using the Wechsler memory scale-logical memory, was preserved in the ACS group. An age-restricted sub-analysis showed significant verbal memory preservation by ACS in participants who were in their 60s (active, n = 12; placebo, n = 9; p = 0.048) and 70s (active, n = 7; placebo, n = 11; p = 0.017). The suppression of CCL24 expression was greatest in people who were in their 70s (p < 0.01). There was a significant correlation between the preservation of verbal memory and suppression of CCL24 expression in the group that was in the 70s (Poisson correlation, r = 0.46, p < 0.05). These results suggest that ACS may preserve verbal episodic memory, probably owing to CCL24 suppression in the blood, especially in elderly participants.

Effect of Anserine/Carnosine Supplementation on Verbal Episodic Memory in Elderly People.

Tatsuhiro Hisatsune, Jun Kaneko, Hiroki Kurashige +6 more

Our goal in this study was to determine whether or not anserine/carnosine supplementation (ACS) is capable of preserving cognitive function of elderly people. In a double-blind randomized controlled trial, volunteers were randomly assigned to an ACS or placebo group at a 1:1 ratio. The ACS group took 1.0 g of an anserine/carnosine (3:1) formula daily for 3 months. Participants were evaluated by psychological tests before and after the 3-month supplementation period. Thirty-nine healthy elderly volunteers (60-78 years old) completed the follow-up tests. Among the tests, delayed recall verbal memory assessed by the Wechsler Memory Scale-Logical Memory showed significant preservation in the ACS group, compared to the placebo group (p = 0.0128). Blood analysis revealed a decreased secretion of inflammatory cytokines, including CCL-2 and IL-8, in the ACS group. MRI analysis using arterial spin labeling showed a suppression in the age-related decline in brain blood flow in the posterior cingulate cortex area in the ACS group, compared to the placebo group (p = 0.0248). In another randomized controlled trial, delayed recall verbal memory showed significant preservation in the ACS group, compared to the placebo group (p = 0.0202). These results collectively suggest that ACS may preserve verbal episodic memory and brain perfusion in elderly people, although further study is needed.

Daily Carnosine and Anserine Supplementation Alters Verbal Episodic Memory and Resting State Network Connectivity in Healthy Elderly Adults.

Jaroslav Rokicki, Lucia Li, Etsuko Imabayashi +3 more

Carnosine and anserine are strong antioxidants, previously demonstrated to reduce cognitive decline in animal studies. We aimed to investigate their cognitive and neurophysiological effects, using functional MRI, on humans. Thirty-one healthy participants (age 40-78, 10 male/21 female) were recruited to a double-blind placebo-controlled study. Participants were assigned to twice-daily doses of imidazole dipeptide formula (n = 14), containing 500 mg (carnosine/anserine, ratio 1/3) or an identical placebo (n = 17). Functional MRI and neuropsychological assessments were carried out at baseline and after 3 months of supplementation. We analyzed resting state functional connectivity with the FSL fMRI analysis package. There were no differences in neuropsychological scores between the groups at baseline. After 3 months of supplementation, the carnosine/anserine group had better verbal episodic memory performance and decreased connectivity in the default mode network, the posterior cingulate cortex and the right fronto parietal network, as compared with the placebo group. Furthermore, there was a correlation between the extents of cognitive and neuroimaging changes. These results suggest that daily carnosine/anserine supplementation can impact cognitive function and that network connectivity changes are associated with its effects.

Creatine supplementation augments skeletal muscle carnosine content in senescence-accelerated mice (SAMP8).

Wim Derave, Glenys Jones, Peter Hespel +1 more

The histidine-containing dipeptides (HCD) carnosine and anserine are found in high concentrations in mammalian skeletal muscle. Given its versatile biologic properties, such as antioxidative, antiglycation, and pH buffering capacity, carnosine has been implicated as a protective factor in the aging process. The present study aimed to systematically explore age-related changes in skeletal muscles HCD content in a murine model of accelerated aging. Additionally, we investigated the effect of lifelong creatine supplementation on muscle HCD content and contractile fatiguability. Male senescence-accelerated mice (SAMP8) were fed control or creatine-supplemented (2% of food intake) diet from the age of 10 to 60 weeks. At week 10, 25, and 60, tibialis anterior muscles were dissected and analysed for HCD and taurine content by HPLC. Soleus and EDL muscles were tested for in vitro contractile fatigue and recovery. From 10 to 60 weeks of age, muscular carnosine (-45%), taurine (-24%), and total creatine (-42%) concentrations gradually and significantly decreased. At 25 but not at 60 weeks, oral creatine supplementation significantly increased carnosine (+88%) and anserine (+40%) content compared to age-matched control-fed animals. Taurine and total creatine content were not affected by creatine supplementation at any age. Creatine-treated mice showed attenuated muscle fatigue (soleus) and enhanced force recovery (m. extensor digitorum longus [EDL]) compared to controls at 25 weeks, but not at 60 weeks. From the present study, we can conclude that skeletal muscle tissue exhibits a significant decline in HCD content at old age. Oral creatine supplementation is able to transiently but potently increase muscle carnosine and anserine content, which coincides with improved resistance to contractile fatigue.

Histidine dipeptide levels in exercised and hypertensive rat muscles.

H Hong, P Johnson

Decreased level of cardiac antioxidants in endurance-trained rats.

M Kihlström, J Ojala, A Salminen

Han-Wistar rats were exposed to a 194-200 h swimming protocol which caused a significant increase in the cardiac weight. The levels of various tissue antioxidants were assayed from the myocardium of the right ventricle and from the left ventricle (subendo- and subepimyocardium). This endurance training decreased the activities of catalase in the right ventricle and in the subendo- and subepimyocardium and Cu,Zn-superoxide dismutase in the subendomyocardium as well as the concentration of vitamin E in the right ventricle and in the subendomyocardium. Also, the activity of thioredoxin reductase decreased in each part of myocardium and that of glutathione reductase in the right ventricle and in the subepimyocardium. The activity of glucose-6-phosphate dehydrogenase increased in the right ventricle and in the subepimyocardium. The activity of glutathione peroxidase and the total tissue contents of carnosine and anserine and tissue sulphydryl groups remained unchanged as compared to the control group. The endurance training caused only minor changes in the regional distribution of antioxidants. The major findings were the disappearance of the difference in the activity of catalase between the right and the left ventricle and the increase in the activity of glucose-6-phosphate dehydrogenase as compared to that of the left ventricle. The results show that endurance training by swimming decreases the level of cardiac antioxidants. This decrease may be due to the increased oxygen metabolism and the subsequent increase in the formation of oxygen free radicals, which could deplete the antioxidant pool.