Exercise fatigue is a complex physiological and psychological phenomenon that includes peripheral fatigue in the muscles and central fatigue in the brain. Peripheral fatigue refers to the loss of force caused at the distal end of the neuromuscular junction, whereas central fatigue involves decreased motor output from the primary motor cortex, which is associated with modulations at anatomical sites proximal to nerves that innervate skeletal muscle. The central regulatory failure reflects a progressive decline in the central nervous system’s capacity to recruit motor units during sustained physical activity. Emerging evidence highlights the critical involvement of central neurochemical regulation in fatigue development, particularly through neurotransmitter-mediated modulation. Alterations in neurotransmitter release and receptor activity could influence excitatory and inhibitory signal pathways, thus modulating the perception of fatigue and exercise performance. Increased serotonin (5-HT) could increase perception of effort and lethargy, reduce motor drive to continue exercising, and contribute to exercise fatigue. Decreased dopamine (DA) and noradrenaline (NE) neurotransmission can negatively impact arousal, mood, motivation, and reward mechanisms and impair exercise performance. Furthermore, the serotonergic and dopaminergic systems interact with each other; a low 5-HT/DA ratio enhances motor motivation and improves performance, and a high 5-HT/DA ratio heightens fatigue perception and leads to decreased performance. The expression and activity of neurotransmitter receptors would be changed during prolonged exercise to fatigue, affecting the transmission of nerve signals. Prolonged high-intensity exercise causes excess 5-HT to overflow from the synaptic cleft to the axonal initial segment and activates the 5-HT1A receptor, thereby inhibiting the action potential of motor neurons and affecting the recruitment of motor units. During exercise to fatigue, the DA secretion is decreased, which blocks the binding of DA to D1 receptor in the caudate putamen and inhibits the activation of the direct pathway of the basal ganglia to suppress movement, meanwhile the binding of DA to D2 receptor is restrained in the caudate putamen, which activates the indirect pathway of the basal ganglia to influence motivation. Furthermore, other neurotransmitters and their receptors, such as adenosine (ADO), glutamic acid (Glu), and γ‑aminobutyric acid (GABA) also play important roles in regulating neurotransmitter balance and fatigue. The occurrence of central fatigue is not the result of the action of a single neurotransmitter system, but a comprehensive manifestation of the interaction between multiple neurotransmitters. This review explores the important role of neurotransmitters and their receptors in central motor fatigue, reveals the dynamic changes of different neurotransmitters such as 5-HT, DA, NE, and ADO during exercise, and summarizes the mechanisms by which these neurotransmitters and their receptors regulate fatigue perception and exercise performance through complex interactions. Besides, this study presents pharmacological evidence that drugs such as agonists, antagonists, and reuptake inhibitors could affect exercise performance by regulating the metabolic changes of neurotransmitters. Recently, emerging interventions such as dietary bioactive components intake and transcranial electrical stimulation may provide new ideas and strategies for the prevention and alleviation of exercise fatigue by regulating neurotransmitter levels and receptor activity. Overall, this work offers new theoretical insights into the understanding of exercise central fatigue, and future research should further investigate the relationship between neurotransmitters and their receptors and exercise fatigue.

This study aims to investigate the molecular mechanism by which naringin alleviates cerebral ischemia/reperfusion(CI/R) injury through DRP1/LRRK2/MCU signaling axis. A total of 60 SD rats were randomly divided into the sham group, the model group, the sodium Danshensu group, and low-, medium-, and high-dose(50, 100, and 200 mg·kg~(-1)) naringin groups, with 10 rats in each group. Except for the sham group, a transient middle cerebral artery occlusion/reperfusion(tMCAO/R) model was established in SD rats using the suture method. Longa 5-point scale was used to assess neurological deficits. 2,3,5-Triphenyl tetrazolium chloride(TTC) staining was used to detect the volume percentage of cerebral infarction in rats. Hematoxylin-eosin(HE) staining and Nissl staining were employed to assess neuronal structural alterations and the number of Nissl bodies in cortex, respectively. Western blot was used to determine the protein expression levels of B-cell lymphoma-2 gene(Bcl-2), Bcl-2-associated X protein(Bax), cleaved cysteine-aspartate protease-3(cleaved caspase-3), mitochondrial calcium uniporter(MCU), microtubule-associated protein 1 light chain 3(LC3), and P62. Mitochondrial structure and autophagy in cortical neurons were observed by transmission electron microscopy. Immunofluorescence assay was used to quantify the fluorescence intensities of MCU and mitochondrial calcium ion, as well as the co-localization of dynamin-related protein 1(DRP1) with leucine-rich repeat kinase 2(LRRK2) and translocase of outer mitochondrial membrane 20(TOMM20) with LC3 in cortical mitochondria. The results showed that compared with the model group, naringin significantly decreased the volume percentage of cerebral infarction and neurological deficit score in tMCAO/R rats, alleviated the structural damage and Nissl body loss of cortical neurons in tMCAO/R rats, inhibited autophagosomes in cortical neurons, and increased the average diameter of cortical mitochondria. The Western blot results showed that compared to the sham group, the model group exhibited increased levels of cleaved caspase-3, Bax, MCU, and the LC3Ⅱ/LC3Ⅰ ratio in the cortex and reduced protein levels of Bcl-2 and P62. However, naringin down-regulated the protein expression of cleaved caspase-3, Bax, MCU and the ratio of LC3Ⅱ/LC3Ⅰ ratio and up-regulated the expression of Bcl-2 and P62 proteins in cortical area. In addition, immunofluorescence analysis showed that compared with the model group, naringin and positive drug treatments significantly decreased the fluorescence intensities of MCU and mitochondrial calcium ion. Meanwhile, the co-localization of DRP1 with LRRK2 and TOMM20 with LC3 in cortical mitochondria was also decreased significantly after the intervention. These findings suggest that naringin can alleviate cortical neuronal damage in tMCAO/R rats by inhibiting DRP1/LRRK2/MCU-mediated mitochondrial fragmentation and the resultant excessive mitophagy.
Animals ; Rats, Sprague-Dawley ; Reperfusion Injury/genetics* ; Flavanones/administration & dosage* ; Rats ; Dynamins/genetics* ; Male ; Brain Ischemia/genetics* ; Protein Serine-Threonine Kinases/genetics* ; Signal Transduction/drug effects* ; Humans ; Drugs, Chinese Herbal/administration & dosage*

The antidepressant activity and molecular mechanisms of Yueju Wan volatile oil were investigated. The Yueju Wan volatile oil was extracted by using supercritical CO_2. Gas chromatography-mass spectrometry(GC-MS) combined with network pharmacology identified 28 chemical constituents in Yueju Wan volatile oil, primarily terpenes and lactones. A total of 123 overlapping targets were associated with depression, including core targets of interleukin-1β(IL-1β), signal transducer and activator of transcription 3(STAT3), and caspase-3(CASP3). These targets were mainly involved in the prolactin, advanced glycation end products/receptor(AGE/RAGE), and phosphoinositide 3-kinase/protein kinase B(PI3K/Akt) signaling pathways. A reserpine-induced depression mouse model was established to evaluate the therapeutic effects and mechanisms of Yueju Wan volatile oil. The effects of Yueju Wan volatile oil on depression-like behavior in mice were evaluated by analyzing body mass, body temperature index, tail suspension immobility time, forced swimming immobility time, and sucrose preference. Hematoxylin-eosin(HE) staining revealed neuronal protection of Yueju Wan volatile oil in the brain of mice. Enzyme-linked immunosorbent assay(ELISA) and Western blot were employed to detect the protein expression of AGEs, IL-1β, phosphorylated PI3K(p-PI3K), Akt, phosphorylated Akt(p-Akt), nuclear factor κB(NF-κB), and brain-derived neurotrophic factor(BDNF). Behavioral evaluation showed that Yueju Wan volatile oil could effectively control the decline of body mass and body temperature of depressed mice, reduce tail suspension and swimming immobility time, and enhance their preference for sucrose. Histopathological examination showed that Yueju Wan volatile oil could alleviate the neuronal damage in CA1 and dentate gyrus(DG) of the hippocampus of mice. ELISA and Western blot results showed that Yueju Wan volatile oil could significantly increase the protein expression levels of PI3K, Akt, and BDNF and significantly decrease the protein expression levels of AGEs, IL-1β, p-PI3K, p-Akt, and NF-κB in the hippocampus of mice. Furthermore, the p-PI3K/PI3K and p-Akt/Akt ratios were significantly decreased at medium and high doses. These findings suggest that the aromatherapy of Yueju Wan volatile oil can significantly improve reserpine-induced depression-like behavior in mice, which may be related to reducing the expression of neuronal membrane protein AGEs, reducing the phosphorylation levels of PI3K and Akt, inhibiting NF-κB entry into the nucleus, and alleviating the release of pro-inflammatory factors and nerve injury.
Animals ; Antidepressive Agents/chemistry* ; Mice ; Proto-Oncogene Proteins c-akt/immunology* ; Phosphatidylinositol 3-Kinases/immunology* ; Oils, Volatile/chemistry* ; Male ; Drugs, Chinese Herbal/chemistry* ; Signal Transduction/drug effects* ; Depression/metabolism* ; Glycation End Products, Advanced/immunology* ; Humans

Compounds isolated from Epimedium include the total flavonoids of Epimedium , icariin, and its metabolites (icaritin, icariside I, and icariside II), which have similar molecular structures. Modern pharmacological research and clinical practice have proved that Epimedium and its active components have a wide range of pharmacological effects, especially in improving sexual function, hormone regulation, anti-osteoporosis, immune function regulation, anti-oxidation, and anti-tumor activity. To date, we still need a comprehensive source of knowledge about the pharmacological effects of Epimedium and its bioactive compounds on the male reproductive system. However, their actions in other tissues have been reviewed in recent years. This review critically focuses on the Epimedium , its bioactive compounds, and the biochemical and molecular mechanisms that modulate vital pathways associated with the male reproductive system. Such intrinsic knowledge will significantly further studies on the Epimedium and its bioactive compounds that protect the male reproductive system and provide some guidances for clinical treatment of related male reproductive disorders.
Male ; Epimedium/chemistry* ; Humans ; Genitalia, Male/drug effects* ; Flavonoids/therapeutic use* ; Animals

OBJECTIVE: To examine the effectiveness of Chinese medicine (CM) Lianhua Qingwen Granule (LHQW) and Jingyin Gubiao Prescription (JYGB) in asymptomatic or mild patients with Omicron infection in the shelter hospital. METHODS: This single-center retrospective cohort study was conducted in the largest shelter hospital in Shanghai, China, from April 10, 2022 to May 30, 2022. A total of 56,244 asymptomatic and mild Omicron cases were included and divided into 4 groups, i.e., non-administration group (23,702 cases), LHQW group (11,576 cases), JYGB group (12,112 cases), and dual combination of LHQW and JYGB group (8,854 cases). The length of stay (LOS) in the hospital was used to assess the effectiveness of LHQW and JYGB treatment on Omicron infection. RESULTS: Patients aged 41-60 years, with nadir threshold cycle (C_T) value of N gene <25, or those fully vaccinated preferred to receive CM therapy. Before or after propensity score matching (PSM), the multiple linear regression showed that LHQW and JYGB treatment were independent influence factors of LOS (both P<0.001). After PSM, there were significant differences in LOS between the LHQW/JYGB combination and the other groups (P<0.01). The results of factorial design ANOVA proved that the LHQW/JYGB combination therapy synergistically shortened LOS (P=0.032). CONCLUSIONS Patients with a nadir C_T value <25 were more likely to accept CM. The LHQW/JYGB combination therapy could shorten the LOS of Omicron-infected individuals in an isolated environment.
Humans ; Drugs, Chinese Herbal/therapeutic use* ; Male ; Female ; Middle Aged ; Adult ; China/epidemiology* ; Hospitalization ; COVID-19 Drug Treatment ; COVID-19/epidemiology* ; SARS-CoV-2 ; Retrospective Studies ; Treatment Outcome ; Length of Stay ; Young Adult ; Aged

Objective To explore the accumulated effects of physical activity,sedentary behavior,and sleep on cardiorespiratory fitness(CRF)among college students and provide effective measures for enhancing their CRF. Methods From May to June in 2023,223 college students aged 18 to 24 years old were recruited from Tianjin University of Science and Technology for a 24 hours activity behavior survey and CRF testing.Compositional analysis was employed to investigate the relationships of physical activity,sedentary behavior,and sleep with CRF.Isotemporal substitution models were established to predict the effects of substituting various activity behaviors on CRF.Results The proportion of time spent on moderate-to-vigorous physical activity(MVPA)was positively correlated with CRF of college students(β=6.40,P=0.002),while the proportion of time spent on sedentary behavior was negatively correlated with CRF(β=-3.02,P=0.004).Light physical activity(LPA)and sleep were not correlated with CRF(β=-1.06,P=0.504).Isotemporal substitution results for 15-min increments showed that replacing other activity behaviors with MVPA significantly increased the CRF of college students[SB:1.72 mL/(kg·min),95% CI=0.94-2.51;LPA:1.82 mL/(kg·min),95% CI=0.95-2.68;sleep:1.64 mL/(kg·min),95% CI=0.84-2.45].In the dose-response relationship from -30 min to 30 min,reallocating time from other behaviors to MVPA had greater adverse effect on CRF than reallocating time from MVPA to other behaviors.Among all the substitutions,replacing LPA with MVPA had the most beneficial effect on improving CRF.Additionally,a 5-min increment was considered the optimal tipping point for MVPA replacing other activities.Conclusions This study underscores the importance of participating in MVPA for improving the CRF of college students.The isotemporal substitution model provides clear goals for the allocation of time for these behaviors,aiding in future intervention measure development and policy-making.
Humans ; Sedentary Behavior ; Sleep ; Students ; Cardiorespiratory Fitness ; Exercise ; Young Adult ; Adolescent ; Universities ; Male ; Female

Objective To explore the effects of time reallocation among moderate-to-vigorous physical activity(MVPA),light physical activity(LPA),sedentary behavior(SB),and sleep on a body shape index(ABSI),body roundness index(BRI),conicity index(CI),and relative fat mass(RFM)of college students by the compositional isotemporal substitution method,thus providing measures for alleviating the obesity problem of college students. Methods Two hundred and ten college students(111 males and 99 females)aged 18-22 years old were recruited from Tianjin University of Science and Technology from April to June in 2023.Three-dimensional acceleration sensors were used to collect data of MVPA,LPA,SB,and sleep of college students.The body height,body weight,and waist circumference were measured,and four novel obesity indicators(ABSI,BRI,CI,and RFM)were calculated.The effects of substituting each activity behavior for 15 min on the obesity indicators were predicted,and the dose-effect relationship was explored at intervals of 5 min from -30 to 30 min.Results MVPA was negatively correlated with ABSI(β=-0.03,P=0.001),BRI(β=-0.27,P=0.049),CI(β=-0.10,P=0.001),and RFM(β=-9.95,P=0.004).LPA was negatively correlated with CI(β=-0.05,P=0.011)and RFM(β=-8.74,P=0.007).Neither SB nor sleep had correlations with ABSI,BRI,CI,and RFM.The results of 15 min isotemporal substitutions showed that increasing the MVPA time decreased the ABSI,BRI,CI,and RFM by 0.006-0.008,0.306-0.393,0.162-0.205,and 2.468-2.897,respectively.Decreasing the MVPA time increased the ABSI,BRI,CI,and RFM by 0.012-0.014,0.548-0.632,0.286-0.328,and 4.358-4.748,respectively.In the dose-effect relationship from -30 min to 30 min,MVPA was irreplaceable,and the negative benefits from substituting MVPA for other activity behaviors were much greater than the positive benefits from substituting MVPA for other activity behaviors.Conclusions Future research should take 24 hours activity behaviors as a whole.Increasing the time spent on MVPA and LPA and decreasing the time spent on SB is one of the effective ways to alleviate the obesity problem among college students.
Humans ; Male ; Students ; Female ; Young Adult ; Obesity ; Sleep ; Adolescent ; Exercise ; Universities ; Sedentary Behavior ; Body Mass Index ; Body Weight

OBJECTIVE: To investigate the effects of Danmu Extract Syrup (DMS) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and explore the mechanism. METHODS: Seventy-two male Balb/C mice were randomly divided into 6 groups according to a random number table (n=12), including control (normal saline), LPS (5 mg/kg), LPS+DMS 2.5 mL/kg, LPS+DMS 5 mL/kg, LPS+DMS 10 mL/kg, and LPS+Dexamethasone (DXM, 5 mg/kg) groups. After pretreatment with DMS and DXM, the ALI mice model was induced by LPS, and the bronchoalveolar lavage fluid (BALF) were collected to determine protein concentration, cell counts and inflammatory cytokines. The lung tissues of mice were stained with hematoxylin-eosin, and the wet/dry weight ratio (W/D) of lung tissue was calculated. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1 β in BALF of mice were detected by enzyme linked immunosorbent assay. The expression levels of Claudin-5, vascular endothelial (VE)-cadherin, vascular endothelial growth factor (VEGF), phospho-protein kinase B (p-Akt) and Akt were detected by Western blot analysis. RESULTS: DMS pre-treatment significantly ameliorated lung histopathological changes. Compared with the LPS group, the W/D ratio and protein contents in BALF were obviously reduced after DMS pretreatment (P<0.05 or P<0.01). The number of cells in BALF and myeloperoxidase (MPO) activity decreased significantly after DMS pretreatment (P<0.05 or P<0.01). DMS pre-treatment decreased the levels of TNF-α, IL-6 and IL-1 β (P<0.01). Meanwhile, DMS activated the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway and reversed the expressions of Claudin-5, VE-cadherin and VEGF (P<0.01). CONCLUSIONS DMS attenuated LPS-induced ALI in mice through repairing endothelial barrier. It might be a potential therapeutic drug for LPS-induced lung injury.
Mice ; Male ; Animals ; Proto-Oncogene Proteins c-akt/metabolism* ; Lipopolysaccharides ; Phosphatidylinositol 3-Kinases/metabolism* ; Interleukin-1beta/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Claudin-5/metabolism* ; Acute Lung Injury/chemically induced* ; Lung/pathology* ; Interleukin-6/metabolism* ; Drugs, Chinese Herbal

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by muscle rigidity, resting tremor, and postural instability, which severely impair the quality of life in middle-aged and elderly individuals. PD’s pathogenesis is complex, involving oxidative stress, immune inflammation, and genetic factors. Despite extensive research, precise therapeutic targets for PD remain elusive, necessitating further investigation into its underlying mechanisms. Recent studies highlight the pivotal role of regional brain iron overload, oxidative stress, and lipid peroxidation in PD’s pathogenesis. Ferroptosis, a form of regulated cell death driven by iron dependency and lipid peroxidation, has emerged as a critical factor in PD pathology. This review examines the relationship between ferroptosis and PD and explores the potential of exercise as a therapeutic intervention to modulate ferroptosis and alleviate PD symptoms. Ferroptosis, distinct from other forms of cell death such as necrosis, autophagy, pyroptosis, and apoptosis, is characterized by mitochondrial shrinkage, reduced cristae, and membrane collapse, without nuclear fragmentation, DNA cleavage, or caspase activation. It is induced by the accumulation of intracellular Fe²⁺, which enhances lipid peroxidation and reactive oxygen species (ROS) generation, ultimately leading to cell death. Studies show disrupted iron metabolism in PD patients, with elevated iron levels in dopaminergic neurons of the substantia nigra correlating with disease severity. Iron chelation therapy has shown promise in alleviating PD symptoms by reducing brain iron levels, highlighting the significance of iron metabolism in PD pathogenesis. Lipid peroxidation, a hallmark of ferroptosis, involves the oxidation of polyunsaturated fatty acids (PUFAs) in cell membranes, compromising membrane integrity and increasing permeability. Elevated lipid peroxidation in the substantia nigra contributes to neuronal damage in PD. Enzymes such as ACSL4 and LPCAT3, crucial in PUFA metabolism, play significant roles in ferroptosis. Exercise has been shown to modulate these enzymes, potentially reducing lipid peroxidation and preventing ferroptosis in PD. Glutathione (GSH) metabolism is another crucial factor in ferroptosis regulation. GSH depletion impairs ROS detoxification, exacerbating oxidative stress and lipid peroxidation. PD patients exhibit reduced GSH levels in the substantia nigra, making dopaminergic neurons more vulnerable to oxidative damage. Exercise enhances GSH synthesis and activity, mitigating oxidative stress and ferroptosis in PD. α-Synuclein aggregation, a hallmark of PD, is closely linked to iron metabolism and oxidative stress. Excessive α‑synuclein binds to iron, promoting its aggregation and inducing ferroptosis. Exercise has been found to reduceα-synuclein accumulation and its pathological phosphorylation, potentially through the upregulation of neuroprotective proteins like DJ-1 and Irisin. These proteins enhance antioxidant defenses and facilitate α‑synuclein degradation, providing a protective effect against PD progression. Additionally, glutamate excitotoxicity, driven by dysregulated glutamate metabolism and receptor activity, contributes to ferroptosis in PD. Exercise modulates glutamate levels and receptor expression, reducing excitotoxicity and iron-induced neuronal damage. In conclusion, emerging research suggests that exercise may inhibit ferroptosis through multiple mechanisms, including regulation of iron metabolism, enhancement of antioxidant defenses, reduction of α-synuclein aggregation, and modulation of glutamate metabolism. These findings highlight the potential of exercise as a non-pharmacological intervention in the prevention and treatment of PD. Further research is needed to elucidate precise mechanisms and optimize exercise protocols for maximum therapeutic benefit.

Objective To explore the effect of quercetin combined with iron death inhibitor Ferrostain-1 on oxalate-induced HK-2 cell injury.Methods HK-2 cells were randomly divided into control group(normal cultured cells),model group(0.5 mmol·L-1 calcium oxalate crystals),quercetin group(0.5 mmol·L-1 calcium oxalate crystals+100 μmol·L-1 quercetin),inhibitor group(0.5 mmol·L-1 calcium oxalate crystals+8 μmol·L-1 Ferrostain-1)and combination group(0.5 mmol·L-1calcium oxalate crystals+100 μmol·L-1quercetin+8 μmol·L-1 Ferrostain-1).Cell counting kit-8(CCK-8)assay was used to detect cell survival rate;Western blot was used to detect iron death related protein expression such as glutathione peroxidase 4(GPX4);flow cytometry and Tunel assay were used to detect cell apoptosis,and assay kit was used to detect cellular iron ions and antioxidant levels.Results The cell survival rates of control group,model group,quercetin group,inhibitor group and combination group were(100.00±2.55)％,(54.49±4.11)％,(64.26±6.30)％,(58.03±3.04)％and(79.37±4.29)％,respectively;GPX4 protein expression levels were 0.98±0.11,0.33±0.05,0.56±0.05,0.78±0.07 and 1.11±0.11,respectively;cell apoptosis rates were(4.15±0.28)％,(23.12±2.49)％,(17.28±1.07)％,(15.08±1.41)％and(8.95±0.75)％,respectively;Fe2+levels were(100.00±0.87)％,(162.55±14.70)％,(149.09±9.50)％,(144.95±11.12)％and(131.76±12.18)％,respectively;superoxide dismutase(SOD)levels were(58.67±3.46),(21.56±1.32),(33.60±2.03),(35.15±3.02)and(44.27±3.89)U·mL-1,respectively.The above indicators of the model group were compared with the control group,and the above indicators of the quercetin group,inhibitor group,and combination group were compared with the model group,the above indicators of the combination group were compared with the quercetin group,and inhibitor group,all they all showed statistical significance(all P＜0.05).Conclusion Iron death inhibitors can enhance the inhibitory effect of quercetin in vitro on oxalate-induced renal tubular epithelial cell injury.