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Background/Objectives: Free amino acids substantially contribute to energy metabolism. Also, their profile may identify (over)training status and effectiveness. The long-term effects of speed-power training on plasma free amino acid (PFAA) profiles are not known. We aimed to observe variations in PFAA levels in high-performance sprinters in a six-month training cycle. Methods: Ten male athletes (24.6 ± 3.3 years) were examined during four training phases: transition (1 month), general preparation (2 months), specific preparation (1 month), and pre-competition/competition (2 months). Venous blood was collected at rest, after exhaustive exercise, and recovery. Forty-two PFAAs were analyzed by the LC-ESI-MS/MS method. Results: Significant decreases in resting concentrations were observed between the transition and competition phases for glutamine (762 ± 117 vs. 623 ± 53 μmol∙L−1; p < 0.001, η2 = 0.47) and histidine (89 ± 15 vs. 75 ± 10 μmol∙L−1; p = 0.010, η2 = 0.27), whereas β-alanine (30 ± 7 vs. 41 ± 9 μmol∙L−1; p = 0.024, η2 = 016) and sarcosine (3.6 ± 0.4 vs. 4.8 ± 0.6 μmol∙L−1; p = 0.006, η2 = 0.188) levels increased. Between the specific and competition phases, significant decreases in the resting levels of 1-methylhistidine (22.1 ± 19.4 vs. 9.6 ± 8.8 μmol∙L−1; p = 0.14, η2 = 0.19), 3-methylhistidine (7.1 ± 1.5 vs. 6.5 ± 1.6 μmol∙L−1; p = 0.009, η2 = 0.18), citrulline (40 ± 10 vs. 29 ± 4 μmol∙L−1; p = 0.05, η2 = 0.29), and ornithine (74 ± 15 vs. 56 ± 10 μmol∙L−1; p = 0.015, η2 = 185) were noticed. Also, for β-alanine and sarcosine, the pattern of response to exercise strongly changed between the training phases. Blood ammonia levels at exhaustion decreased between the transition and competition phases (32 ± 4 vs. 23 ± 5 μmol∙L−1; p < 0.001, η2 = 0.67), while lactate, the phenylalanine–tyrosine ratio, the glutamine–glutamate ratio, hematological parameters, and cardiorespiratory indices remained at similar levels. Conclusions: Speed-power training seems to affect PFAAs involved in skeletal muscle metabolic pathways responsible for neutralizing toxic ammonia (glutamine, arginine, citrulline, ornithine), attenuating the deleterious effects of H+ ions (histidine, β-alanine), and reducing exercise-induced protein breakdown (1- and 3-methylhistidine). Our findings suggest that sprint-oriented training supports metabolic pathways that are responsible for the removal of harmful metabolites produced during exercise. [ABSTRACT FROM AUTHOR]

Circulating blood is an important plasma free amino acids (PFAAs) reservoir and a pivotal link between metabolic pathways. No comparisons are available between athletes with opposite training adaptations that include a broader spectrum of both proteinogenic and non-proteinogenic amino acids, and that take into account skeletal muscle mass. We hypothesized that the levels of the exercise-induced PFAAs concentration are related to the type of training-related metabolic adaptation. We compared highly trained endurance athletes (n = 11) and sprinters (n = 10) aged 20‒35 years who performed incremental exercise until exhaustion. Venous blood was collected before and during the test and 30-min recovery (12 samples). Forty-two PFAAs were assayed using LC-ESI-MS/MS technique. Skeletal muscle mass was estimated using dual X-ray absorptiometry method. Glutamine and alanine were dominant PFAAs throughout the whole exercise and recovery period (~350‒650 μmol∙L-1). Total, combined proteinogenic, non-essential, and non-proteinogenic PFAAs levels were significantly higher in endurance athletes than sprinters (ANOVA group effects: p = 0.007, η2 = 0.321; p = 0.011, η2 = 0.294; p = 0.003, η2 = 0.376; p = 0.001, η2 = 0.471, respectively). The exercise response was more pronounced in endurance athletes, especially for non-proteinogenic PFAAs (ANOVA interaction effect: p = 0.038, η2 = 0.123). Significant between-group differences were observed for 19 of 33 PFAAs detected, including 4 essential, 7 non-essential, and 8 non-proteinogenic ones. We demonstrated that the PFAAs response to incremental aerobic exercise is associated with the type of training-related metabolic adaptation. A greater turnover and availability of circulating PFAAs for skeletal muscles and other body tissues is observed in endurance- than in sprint-trained individuals. Non-proteinogenic PFAAs, despite low concentrations, also respond to exercise loads, indicating their important, though less understood role in exercise metabolism. Our study provides additional insight into the exercise-induced physiological response of PFAAs, and may also provide a rationale in discussions regarding dietary amino acid requirements in high-performance athletes with respect to sports specialization. [ABSTRACT FROM AUTHOR]

Patients with phenylketonuria (PKU) must restrict their intake of phenylalanine, which can also affect the levels of other essential and non-essential amino acids due to inadequate supply. Therefore, our objective was to assess amino acids in serum samples from 20 PKU patients and compare them with results from 51 healthy subjects. A sample analysis was conducted using liquid chromatography–tandem mass spectrometry. We obtained levels of 28 substances, including amino acids, biogenic amines, carnitine, and acetylcarnitine. Kynurenine (p = 0.000001), tyrosine (p = 0.0002), asparagine (p = 0.001), proline (p = 0.012), and the kynurenine/tryptophan ratio (p < 0.000001) were identified as features that differed between the studied groups, being significantly lower in patients with PKU. Glycine (p = 0.000012), putrescine (p = 0.0055), asymmetric dimethylarginine (p = 0.01), creatinine (p = 0.035) levels, as well as the total level of glucogenic amino acids (p = 0.0018), and the ratios of putrescine/ornithine (p = 0.003) and citrulline/ornithine (p = 0.0043) were significantly higher in the PKU group. In conclusion, the amino acid profiles in patients with PKU differ significantly from those in healthy peers, with potential clinical implications. These findings confirm the importance of metabolic testing in clinical practice and highlight the necessity for adequate dietary monitoring and adjustment. [ABSTRACT FROM AUTHOR]

We aimed to evaluate long-term changes in proteinogenic and non-proteinogenic plasma free amino acids (PFAA). Eleven male endurance triathletes participated in a 9-month study. Blood was collected at rest, immediately after exhaustive exercise, and during 30-min recovery, in four consecutive training phases: transition, general, specific, and competition. Twenty proteinogenic and 22 non-proteinogenic PFAAs were assayed using the LC-ESI-MS/MS technique. The structured training modified the patterns of exercise-induced PFAA response, with the competition phase being the most distinct from the others. Branched-chain amino acids (p = 0.002; η2 = 0.216), phenylalanine (p = 0.015; η2 = 0.153), methionine (p = 0.002; η2 = 0.206), and lysine (p = 0.006; η2 = 0.196) declined more rapidly between rest and exhaustion in the competition phase. Glutamine (p = 0.008; η2 = 0.255), glutamate (p = 0.006; η2 = 0.265), tyrosine (p = 0.001; η2 = 0.195), cystine (p = 0.042; η2 = 0.183), and serine (p < 0.001; η2 = 0.346) levels were reduced in the competition phase. Arginine (p = 0.046; η2 = 0.138) and aspartate (p = 0.011; η2 = 0.171) levels were highest during exercise in the transition phase. During the competition phase, α-aminoadipic acid (p = 0.023; η2 = 0.145), β-aminoisobutyric acid (p = 0.007; η2 = 0.167), β-alanine (p < 0.001; η2 = 0.473), and sarcosine (p = 0.017; η2 = 0.150) levels increased, whereas phosphoethanolamine (p = 0.037; η2 = 0.189) and taurine (p = 0.008; η2 = 0.251) concentrations decreased. Overtraining indicators were not elevated. The altered PFAA profile suggests adaptations within energy metabolic pathways such as the tricarboxylic acid cycle, oxidative phosphorylation, ammonia neutralization, the purine nucleotide cycle, and buffering of intracellular H+ ions. The changes seem to reflect normal adaptations. [ABSTRACT FROM AUTHOR]

Taurine, a non-proteogenic amino acid and commonly used nutritional supplement, can protect various tissues from degeneration associated with the action of the DNA-damaging chemotherapeutic agent cisplatin. Whether and how taurine protects human ovarian cancer (OC) cells from DNA damage caused by cisplatin is not well understood. We found that OC ascites-derived cells contained significantly more intracellular taurine than cell culture-modeled OC. In culture, elevation of intracellular taurine concentration to OC ascites-cell-associated levels suppressed proliferation of various OC cell lines and patient-derived organoids, reduced glycolysis, and induced cell protection from cisplatin. Taurine cell protection was associated with decreased DNA damage in response to cisplatin. A combination of RNA sequencing, reverse-phase protein arrays, live-cell microscopy, flow cytometry, and biochemical validation experiments provided evidence for taurine-mediated induction of mutant or wild-type p53 binding to DNA, activation of p53 effectors involved in negative regulation of the cell cycle (p21), and glycolysis (TIGAR). Paradoxically, taurine's suppression of cell proliferation was associated with activation of pro-mitogenic signal transduction including ERK, mTOR, and increased mRNA expression of major DNA damage-sensing molecules such as DNAPK, ATM and ATR. While inhibition of ERK or p53 did not interfere with taurine's ability to protect cells from cisplatin, suppression of mTOR with Torin2, a clinically relevant inhibitor that also targets DNAPK and ATM/ATR, broke taurine's cell protection. Our studies implicate that elevation of intracellular taurine could suppress cell growth and metabolism, and activate cell protective mechanisms involving mTOR and DNA damage-sensing signal transducti. [ABSTRACT FROM AUTHOR]

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Dermocosmetics are products intended for sensitive and problematic skin. They are a good solution for additional care of skin affected by conditions such as atopic dermatitis, acne, psoriasis, or for couperose skin. The compounds of particular importance in the care of atopic skin include ceramides, ectoine, hyaluronic acid, vitamins A and E, as well as natural vegetable oils. The aim of this work was to develop a qualitative and quantitative approach and to investigate the characteristics of formulations such as a face cream, topical cream, body lotion, and cleansing foam dedicated to patients with atopic dermatitis. The finished cosmetic formulation was evaluated by performing formulation stability tests at different times and temperatures, together with packaging compatibility and organoleptic evaluation. Preservative tests were carried out to determine the efficacy of the preservative. In addition, dermatological and instrumental tests were done to verify the product properties. The newly developed cosmetic formulations showed good physical and chemical characteristics, typical of this type of product. They were also structurally and microbiologically stable during storage at various temperatures. Dermatological tests did not reveal any irritating or allergenic properties. The best data were obtained for the face cream--namely improvement of skin hydration by 21.88%, reduction of transepidermal water loss by 15.86%, alleviation of erythema by 15.77%, and of skin sensitivity by 17.20%. This work resulted in the preparation of innovative dermocosmetics to be used for atopic skin. The cosmetics have a unique composition and delicate formula, show high biofunctionality, and meet all the requirements for cosmetic products intended for marketing. [ABSTRACT FROM AUTHOR]

Honeybee venom (HBV) is a product of natural origin with an extremely complex composition. It exhibits several beneficial pharmacological properties, for example anti-inflammatory, antimicrobial, antidiabetic, anti-arthritic, and anti-tumor activities. On the other hand, HBV contains highly allergenic components, including melittin, which makes up more than 50% of its dry weight. Despite many studies conducted, HBV's components and mechanism of action are not yet fully known and understood. Therefore, to enhance the safety of its therapeutical applications, it is essential to establish HBV's composition and biological properties. Many analytical techniques and methods have been reported as potentially useful for the determination of new HBV constituents. Studies focus mainly on the analyses of the HBV proteome and metabolome. Also, the properties of its components when applied to the skin, as well as its allergenicity, are being studied. Currently, the most commonly used methods for HBV analysis include high-performance liquid chromatography and mass spectrometry. Choosing the correct and most applicable method for HBV analysis is of great importance in order to obtain in-depth results crucial for understanding of its mechanism of biological action. The diversity of chemical compounds in HBV also entails an appropriate sample preparation at the pre-analytical stage. In order to summarise the latest knowledge on techniques for the analysis of complex natural products, on the example of HBV, this review paper discusses the modern analytical tools of HBV characterization, focusing on metabolomic and proteomic studies, topical applications, investigation of venom allergies, and the prospects for future research. [ABSTRACT FROM AUTHOR]