Effects of dietary ß-alanine supplementation on growth performance, meat quality, carnosine content, amino acid composition and muscular antioxidant capacity in Chinese indigenous Ningxiang pig.

ß-alanine has been demonstrated to improve carcass traits and meat quality of animals. However, no research has been found on the effects of dietary ß-alanine in the meat quality control of finishing pigs, which are among the research focus. Therefore, this study aimed to evaluate the effects of dietary ß-alanine supplementation on growth performance, meat quality, carnosine content, amino acid composition and muscular antioxidant capacity of Chinese indigenous Ningxiang pigs. The treatments contained a basal diet (control, CON) and a basal diet supplemented with 600 mg/kg ß-alanine. Each treatment group consisted of five pens, with five pigs per pen. Results showed that compared with CON, supplemental ß-alanine did not affect the final body weight, average daily gain, average daily feed intake and the feed-to-gain ratio of pigs. Dietary ß-alanine supplementation tended to increase the pH45 min (p = 0.071) while decreasing the shear force (p = 0.085) and the drip loss (p = 0.091). Moreover, it improved (p < 0.05) the activities of glutathione peroxidase and catalase and lessened (p < 0.05) malondialdehyde concentration. Added ß-alanine in diets of finishing pigs could enhance the concentrations of arginine, alanine, and glutamate (p < 0.05) in the longissimus dorsi muscle and tended to raise the levels of cysteine, glycine and anserine (p = 0.060, p = 0.098 and p = 0.091 respectively). Taken together, our results showed that dietary ß-alanine supplementation contributed to the improvement of the carcass traits, meat quality and anserine content, the amelioration of muscle antioxidant capacity and the regulation of amino acid composition in Chinese indigenous Ningxiang pigs.

The ergogenic effect of acute carnosine and anserine supplementation: dosing, timing, and underlying mechanism.

Background: Recent studies suggest that acute-combined carnosine and anserine supplementation has the potential to improve the performance of certain cycling protocols. Yet, data on optimal dose, timing of ingestion, effective exercise range, and mode of action are lacking. Three studies were conducted to establish dosing and timing guidelines concerning carnosine and anserine intake and to unravel the mechanism underlying the ergogenic effects. Methods: First, a dose response study A was conducted in which 11 men randomly received placebo, 10, 20, or 30 mg.kg-1 of both carnosine and anserine. They performed 3x maximal voluntary isometric contractions (MVC), followed by a 5 x 6 s repeated cycling sprint ability test (RSA), once before the supplement and 30 and 60 minutes after. In a second study, 15 men performed 3x MVCs with femoral nerve electrical stimulation, followed by an RSA test, once before 30 mg.kg-1 carnosine and anserine and 60 minutes after. Finally, in study C, eight men performed a high intensity cycling training after randomly ingesting 30 mg.kg-1 of carnosine and anserine, a placebo or antihistamines (reduce post-exercise blood flow) to investigate effects on muscle perfusion. Results: Study A showed a 3% peak power (p = 0.0005; 95% CI = 0.07 to 0.27; ES = 0.91) and 4.5% peak torque (p = 0.0006; 95% CI = 0.12 to 0.50; ES = 0.87) improvement on RSA and MVC, with 30 mg.kg-1 carnosine + anserine ingestion 60 minutes before the performance yielding the best results. Study B found no performance improvement on group level; however, a negative correlation (r = -0.54; p = 0.0053; 95% CI = -0.77 to -0.19) was found between carnosinase enzyme activity (responsible for carnosine and anserine breakdown) and performance improvement. No effect of the supplement on neuromuscular function nor on muscle perfusion was found. Conclusions: These studies reveal that acute ingestion of 30 mg.kg-1 of both carnosine and anserine, 60 minutes before a high intensity exercise, can potentially improve performance, such as short cycling sprints or maximal muscle contractions. Subjects with lower carnosinase activity, and thus a slower breakdown of circulating dipeptides, appear to benefit more from this ergogenic effect. Finally, neither the involvement of a direct effect on neuromuscular function, nor an indirect effect on recovery through increased muscle perfusion could be confirmed as potential mechanism of action. The ergogenic mechanism therefore remains elusive.

The gut microbiota mediates the protective effects of anserine supplementation on hyperuricaemia and associated renal inflammation.

Hyperuricaemia is a disease associated with elevated serum uric acid content, which has emerged rapidly in recent decades. The drugs used to treat clinical hyperuricaemia have side effects, and their safety is poor. However, anserine is a natural carnosine derivative that shows an anti-hyperuricaemic effect. A previous study demonstrated that anserine inhibits uric acid synthesis and promotes uric acid excretion, but there is no evidence regarding the effect of anserine from the perspective of the gut microbiota. In this study, the anti-hyperuricaemic and anti-inflammatory effects of anserine were explored in a diet-induced hyperuricaemic mouse model. Anserine alleviated hyperuricaemia and renal inflammation phenotypes, inhibited uric acid biosynthesis, promoted uric acid excretion, and inhibited NLRP3 inflammasome and TLR4/MyD88/NF-κB signalling pathway activation. The results showed that the anti-hyperuricaemic effect of anserine was dependent on the gut microbiota in the germ-free mice experiment. Furthermore, anserine treatment reversed gut microbiota dysbiosis, repaired the intestinal epithelial barrier and increased short-chain fatty acid production. Moreover, the anti-hyperuricaemic effect of anserine was transmissible by transplanting the faecal microbiota from anserine-treated mice, indicating that the protective effects were at least partially mediated by the gut microbiota. Thus, we identified a new and safe prebiotic material to alleviate hyperuricaemia and provided ideas for the development of oligopeptides.

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

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.

Anserine Reverses Exercise-Induced Oxidative Stress and Preserves Cellular Homeostasis in Healthy Men.

The study tested whether anserine (beta-alanyl-3-methyl-l-histidine), the active ingredient of chicken essence affects exercise-induced oxidative stress, cell integrity, and haematology biomarkers. In a randomized placebo-controlled repeated-measures design, ten healthy men ingested anserine in either a low dose (ANS-LD) 15 mg.kg-1.bw-1, high dose (ANS-HD) 30 mg.kg-1.bw-1, or placebo (PLA), following an exercise challenge (time to exhaustion), on three separate occasions. Anserine supplementation increased superoxide dismutase (SOD) by 50% (p < 0.001, effect size d = 0.8 for both ANS-LD and ANS-HD), and preserved catalase (CAT) activity suggesting an improved antioxidant activity. However, both ANS-LD and ANS-HD elevated glutathione disulfide (GSSG), (both p < 0.001, main treatment effect), and consequently lowered the glutathione to glutathione disulfide (GSH/GSSG) ratio compared with PLA (p < 0.01, main treatment effect), without significant effects on thiobarbituric acid active reactive substances (TBARS). Exercise-induced cell damage biomarkers of glutamic-oxaloacetic transaminase (GOT) and myoglobin were unaffected by anserine. There were slight but significant elevations in glutamate pyruvate transaminase (GPT) and creatine kinase isoenzyme (CKMB), especially in ANS-HD (p < 0.05) compared with ANS-LD or PLA. Haematological biomarkers were largely unaffected by anserine, its dose, and without interaction with post exercise time-course. However, compared with ANS-LD and PLA, ANS-HD increased the mean cell volume (MCV), and decreased the mean corpuscular haemoglobin concentration (MCHC) (p < 0.001). Anserine preserves cellular homoeostasis through enhanced antioxidant activity and protects cell integrity in healthy men, which is important for chronic disease prevention. However, anserine temporal elevated exercise-induced cell-damage, together with enhanced antioxidant activity and haematological responses suggest an augmented exercise-induced adaptative response and recovery.

A zebrafish (danio rerio) model for high-throughput screening food and drugs with uric acid-lowering activity.

With co-treatment of potassium oxonate (PO) and xanthine sodium salt (XSS), a zebrafish larva model of acute hyperuricemia has been constructed for the first time. The results show PO 200 µM + XSS 10 µM, PO 300 µM + XSS 15 µM, and PO 400 µM + XSS 20 µM can significantly increase the level of uric acid in the zebrafish larvae (P < 0.05), the concentrations as described above can be used to construct the zebrafish larvae model of acute hyperuricemia. At the same time, treatment of allopurinol (APL, one of the hyperuricemia drugs) at 2000 µM (P < 0.001) and treatment of anserine (ASE) at 200 µM (P < 0.05) could significantly decrease the level of uric acid in the model group which received PO 200 µM + XSS 10 µM, which demonstrate that such model could offer a new robust approach for high-throughput screening of food and drugs with uric acid-lowering activity.

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

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.

Medicinal plants with inhibitory properties against snake venoms.

Envenomations due to snake bites are commonly treated by parenteral administration of horse or sheep-derived polyclonal antivenoms aimed at the neutralization of toxins. However, despite the widespread success of this therapy, it is still important to search for different venom inhibitors, either synthetic or natural, that could complement or substitute for the action of antivenoms. Several plants have been utilized in folk medicine as antiophidian. However, only a few species have been scientifically investigated and still less had their active components isolated and characterized both structurally and functionally. This article presents a review of plants showing neutralizing properties against snake venoms which were assayed in research laboratories, correlating them with ethnopharmacological studies, as (i) the part of the plant used as antidote, (ii) its respective genus and family and (iii) inhibition of the main pharmacological, toxic and enzymatic activities of snake venoms and isolated toxins. Protective activity of many of these plants against the lethal action of snake venoms has been confirmed by biological assays. Compounds in all of them belong to chemical classes capable of interacting with macromolecular targets (enzymes or receptors). Popular culture can often help to guide scientific studies. In addition, biotechnological application of these inhibitors, as helpful alternative or supplemental treatments to serum therapy, and also as important models for synthesis of new drugs of medical interest, needs to be better oriented and scientifically explored.

Inhibition of plant and mammalian diamine oxidase by substrate analogues.

Imidazoles, aliphatic substrate analogues and the natural dipeptides, carnosine and anserine, were investigated as inhibitors of diamine oxidase from the pig kidney, human pregnancy plasma and pea seedlings. Imidazole, methylimidazoles, N-acetylimidazole, histamine and N tau-methylhistamine are relatively potent inhibitors of mammalian diamine oxidase showing no influence on plant enzymes. Anserine and carnosine are inhibitors of pig kidney and pea seedling enzymes. Ki values are 2 microM and 10 microM respectively. Investigated natural derivatives of putrescine and cadaverine have no influence on diamine oxidase of different origin. In conclusion, we present some evidence to suggest that mammalian diamine oxidase, despite a high reaction rate with putrescine, is better adapted to histamine oxidation, whereas for plant enzymes the diamines are preferred substrates.