Endurance and resistance exercises, alone or in combination, induce metabolic changes that affect tryptophan (Trp) catabolism. The kynurenine pathway (KP) is the main route of Trp degradation, and it is modulated by the inflammatory and redox environments. Previous studies have shown that KP metabolites work as myokines that mediate the positive systemic effects related to exercise. However, it is poorly understood how different exercise modalities and intensities impact the KP. The aim of this study was to characterize the effect of two different exercise modalities, military diving and swimming, on the KP and the redox environment. A total of 34 healthy men from the Mexican Navy were included in the study, 20 divers and 14 swimmers, who started and stayed in military training consistently during the six months of the study; 12 Mexican men without fitness training were used as the control group. Physical fitness was determined at the beginning and after 6 months of training; criteria included body composition; serum levels of Trp, kynurenine (KYN), kynurenic acid (KYNA) and 3-hydroxykynurenine (3-HK); the glutathione ratio (GSH/GSSG); and malondialdehyde (MDA).. Results showed a significant loss of body fat in both the diver and swimmer groups. Compared with the control group, divers showed a decrease in Trp and 3-HK levels, but no changes were observed in the KYN/Trp, KYNA/Trp or 3-HK/Trp ratios, while swimmers showed a decrease in KYN levels and an increase in the KYNA and 3-HK levels. Additionally, divers showed a decrease in the GSH/GSSG ratio and an increase in MDA levels, in contrast to the swimmers, who showed a decrease in MDA levels and an increase in GSH/GSSG levels. Our findings suggest a differential shift in the KP and redox environment induced by diving and swimming. Swimming promotes an antioxidant environment and a peripheral overactivation of the KP.

Multiple sclerosis (MS) is a chronic inflammatory autoimmune neurological disease characterized by the recurrent appearance of demyelinating lesions and progressive disability. Currently, there are multiple disease-modifying treatments, however, there is a significant need to develop new therapeutic targets, especially for the progressive forms of the disease. This review article provides an overview of the most recent studies aimed at understanding the inflammatory processes that are activated in response to the accumulation of kynurenine pathway (KP) metabolites, which exacerbate an imbalance between immune system cells (e.g., Th1, Th2, and T reg) and promote the release of pro-inflammatory interleukins that modulate different mechanisms: membrane-receptors function; nuclear factors expression; and cellular signals. Together, these alterations trigger cell death mechanisms in brain cells and promote neuron loss and axon demyelination. This hypothesis could represent a remarkable approach for disease-modifying therapies for MS. Here, we also provide a perspective on the repositioning of some already approved drugs involved in other signaling pathways, which could represent new therapeutic strategies for MS treatment.

The kynurenine pathway (KP) and the endocannabinoid system (ECS) are known to be deregulated in depression and obesity; however, it has been recognized that acute physical exercise has an important modulating role inducing changes in the mobilization of their respective metabolites—endocannabinoids (eCBs) and kynurenines (KYNs)—which overlap at some points, acting as important antidepressant, anti-nociceptive, anti-inflammatory, and antioxidant biomarkers. Therefore, the aim of this review is to analyze and discuss some recently performed studies to investigate the potential interactions between both systems, particularly those related to exercise-derived endocannabinoidome and kynurenine mechanisms, and to elucidate how prescription of physical exercise could represent a new approach for the clinical management of these two conditions.

The kynurenine pathway (KP) and the endocannabinoid system (ECS) are known to be deregulated in depression and obesity; however, it has been recognized that acute physical exercise has an important modulating role inducing changes in the mobilization of their respective metabolites -endocannabinoids (eCB) and kynurenines (KYN)- which overlap at some points, acting as im-portant antidepressant, anti-nociceptive, anti-inflammatory, and antioxidant biomarkers. There-fore, the aim of this review is to analyze and discuss some studies performed recently to investigate the potential interactions between both systems, particularly, those related with exercise-derived endocannabinoidome and kynurenine mechanisms and to elucidate how, the prescription of physical exercise could represent a new approach for the clinical manage of these two conditions.

Several reports have provided evidence that there are genetic variants of genes such as MSTN, BDRKB2, ACTN3 and ADRB2 that are involved in a better response to adaptation during resistance or strength training, while other genes such as GRB14, AGT and END1 are reported to be associated with the risk of suffering from some diseases such as diabetes, hypertension or obesity. A cross-sectional study from a Mexican Mestizo population was performed to estimate the frequency of 10 gene variants in 8 genes involved in athletic performance or chronic degenerative diseases, MSTN (rs1805085, rs1805086), BDKRB2 (rs1799722), FST (rs1423560), ACTN3 (rs1815739), ADRB2 (rs1042713, rs1042714), GRB14 (rs8192673), AGT (rs699) and EDN1 (rs5370), and to compare frequencies from 26 populations reported in the Database of 1000 Genomes project. Genotype frequencies fitted the Hardy–Weinberg equilibrium, except for MST rs1805086 and FST rs1423560, and our study revealed significant differences in the distribution of frequencies of some of these gene variants among populations reported in the 1000 Genomes Project. Our findings provide insights regarding the genetic background of our population, and future case–control studies can be carried out with more accurate sample sizes for genetic association studies. Our results may be also useful in recognizing the roles and mechanisms contributing to athletic performance and/or chronic degenerative diseases in Mexicans.

It is currently known that meniscal damage has a bidirectional relationship with the onset/development of osteoarthritis (OA), making the development of new therapeutic strategies that comprehensively address both issues crucial. In this context, the present study aimed to evaluate the biological effect of peniocerol (PEN), an emerging phytopharmaceutical, in an in vitro model of inflammation induced by IL-1β and TNF-α in human meniscal fibrochondrocyte cells. Human meniscal fibrochondrocyte cells were isolated, cultured, and treated with different concentrations of PEN to determine those that promote cell proliferation and the IC₅₀ using the MTT assay. The cells were then stimulated with TNF-α (10 ng/mL) or IL-1β (5 ng/mL), with or without PEN (300 and 500 µM). Cell morphology and the expression of ACAN, type I+III collagen, type II collagen, MMP13, and p65 were evaluated by immunofluorescence. Treatment with TNF-α and IL-1β significantly reduced the expression of ACAN and type II collagen, while increasing MMP13 and p65, indicating a degenerative phenotype. Co-treatment with PEN at 300 μM showed partial improvements, while PEN at 500 µM normalized the levels of ACAN, Col2A1, and p65 to values similar to the control, while significantly inhibiting the markers for COL I+III and MMP3. In an in vitro degenerative fibrochondrocyte model, PEN at 500 μM demonstrated its ability to halt extracellular matrix degradation and actively promote its recovery, showing an optimal balance between efficacy and safety as a potential therapeutic strategy for the comprehensive treatment of OA progression.