Lactate, with a chemical formula of C₃H₆O₃, is an intermediate product of glucose metabolism in the body and a raw material for hepatic gluconeogenesis. Under physiological resting conditions, the body mainly relies on aerobic oxidation of sugar and fat for energy supply, so the blood lactate concentration is lower. However, during exercise, the enhanced glycolysis in skeletal muscles leads to the significant release of lactate into the bloodstream, causing a marked increase in blood lactate concentration. Traditionally, lactate has been regarded as a metabolic waste product of glycolysis and a contributor to exercise-induced fatigue. Nevertheless, recent studies have revealed that, in humans, lactate is a major vehicle for carbohydrate carbon distribution and metabolism, serving not only as an energy substance alongside glucose but also as a vital component in various biological pathways involved in cardiac energetics, muscle adaptation, brain function, growth and development, and inflammation therapy. Two primary pathways can elevate lactate levels in neurons during exercise. One is peripheral skeletal muscle-derived lactate, which can enter the bloodstream and cross the blood-brain barrier into the brain with the assistance of monocarboxylate transporters (MCTs) from the solute carrier family 16 (SLC16). The other is the central brain-derived pathway. During exercise, neuronal activity is enhanced, promoting the secretion of neuroactive substances such as glutamate, norepinephrine, and serotonin in the brain. This activates astrocytes to break down glycogen into lactate and stimulates glutamate from the presynaptic terminal into the synaptic cleft. It upregulates the glucose transport protein-1 (GLUT-1) expression, allowing astrocytes to convert glucose into lactate through glycolysis. The lactate is produced via peripheral pathways and central pathways during exercise are transported by astrocyte membrane monocarboxylate transporters MCT1 and MCT4 to the extracellular space, where neurons take it up through neuronal cell membrane MCT2. The lactate in neurons can serve as an alternative energy source of glucose for neuronal functional activities, meeting the increased energy demands of synaptic activity during exercise, and maintaining energy balance and normal physiological function in the brain. Additionally, acting as a signaling molecule lactate can enhance synaptic plasticity through the SIRT1/PGC-1α/FNDC5 and ERK1/2 signaling pathways, lactate can promote angiogenesis by upregulating VEGF-A expression through the PI3K/Akt and ERK1/2 signaling pathways, stimulate neurogenesis via the Akt/PKB signaling pathway, and reduce neuroinflammation through activation of the “lactate timer”. Overall, lactate contributes to the protection of neurons, the promotion of learning and memory, the enhancement of synaptic plasticity, and the reduction of neuroinflammation in the nervous system. While lactate may serve as a potential mediator for information exchange between the peripheral and central nervous systems during exercise, further experimental research is needed to elucidate its action mechanisms in the nervous system. In addition, future studies should utilize advanced neurophysiological and molecular biology techniques to uncover the importance of lactate in maintaining brain function and preventing neurological diseases. Accordingly, this article first reviews the historical research on lactate, then summarizes the metabolic characteristics and neuronal sources of lactate, and finally explores the role and mechanisms of exercise-induced lactate in the nervous system, aiming to provide new perspectives and targets for understanding the mechanisms underlying exercise promotion of brain health.

This study investigated the mechanism of Chaishao Kaiyu Decoction in improving hippocampal neuroinflammation in depressed rats based on complement component 3(C3)/C3 receptor(C3aR). A total of 60 SD rats were randomly divided into a blank group, a model group, high, medium, and low dose groups of Chaishao Kaiyu Decoction, and a positive drug group, with 10 rats in each group. Except for the blank group, chronic unpredictable mild stress(CUMS) was used to construct depression models in other groups. Sucrose preference, open-field experiment, forced swimming, and water maze were used to detect the changes in depression-like behavior in each group. Enzyme-linked immunosorbent assay(ELISA) was used to detect the serum inflammatory factor level in rats, and hematoxylin-eosin(HE) staining and Nissl staining were employed to observe the pathological damage of hippocampal neurons. Golgi-Cox staining was used to observe the dendritic spine damage of hippocampal neurons, and immunofluorescence and Western blot were utilized to detect the expression of microglial marker Iba-1 and C3/C3aR protein in the hippocampus of rats. The behavioral results showed that compared with the model group, Chaishao Kaiyu Decoction could significantly strengthen the sugar water preference, increase the distance and number of voluntary activities, shorten the immobility time in forced swimming and the successful incubation period of positioning navigation, and prolong the stay time of space exploration in the target quadrant. ELISA results showed that the content of inflammatory factors in the hippocampus of depressed rats was significantly higher than that of the blank group, and the content of inflammatory factors decreased significantly after the intervention of Chaishao Kaiyu Decoction. In addition, Chaishao Kaiyu Decoction could relieve pathological damage such as cell swelling and loose arrangement of hippocampus tissue. In the Western blot experiment, the expression levels of C3 and C3aR proteins in the model group were higher than those in the blank group, while the expression of C3 and C3aR in Chaishao Kaiyu Decoction could be down-regulated. Immunofluorescence results showed that compared with the model group, the fluorescence intensity of microglia marker Iba-1 decreased significantly after the intervention of Chaishao Kaiyu Decoction and positive drugs. The antidepressant effect of Chaishao Kaiyu Decoction may be related to the down-regulation of C3/C3aR signaling pathway-related proteins, thus alleviating hippocampal inflammation.
Animals ; Hippocampus/metabolism* ; Rats, Sprague-Dawley ; Drugs, Chinese Herbal/administration & dosage* ; Rats ; Male ; Depression/metabolism* ; Complement C3/metabolism* ; Receptors, Complement/metabolism* ; Humans ; Neuroinflammatory Diseases/genetics*

The triterpenoid saponins of Centella asiatica, including asiaticoside, madecassoside, asiatic acid, and madecassic acid, are pivotal bioactive compounds of the plant. These constituents exhibit a spectrum of pharmacological activities, such as antioxidant, antitumor, and antidepressant effects, promotion of wound healing, and enhancement of microcirculation. Owing to these therapeutic properties, C. asiatica is widely employed in pharmaceutical and cosmetic industries. However, the escalating global demand for its extracts has led to potential supply shortages, prompting researchers to use multiple strategies such as multi-omics, molecular biology, and synthetic biology to conduct extensive studies. These studies encompass the elucidation of the biosynthetic pathways of triterpenoid saponins in C. asiatica, metabolic regulation, the hormonal induction of secondary metabolite synthesis, and the application of biotechnological strategies for natural product production to increase the yield of secondary metabolites in C. asiatica, or to produce active components via microbial chassis, thus satisfying market demands and promoting the sustainable exploitation of wild C. asiatica resources. This article first introduced the triterpenoid saponins of C. asiatica and their biological activities, then summarized the latest research advancements in their biosynthetic pathways, metabolic regulation, and heterologous biosynthesis, and provided an outlook on future development directions, with the aim of providing reference for comprehensive resource development and biotechnological synthesis of active components from C. asiatica.
Centella/genetics* ; Triterpenes/chemistry* ; Biosynthetic Pathways ; Humans ; Drugs, Chinese Herbal/chemistry* ; Plant Extracts

The 95% ethanol extract from bulbs of Narcissus tazetta var. chinensis(BNTC) was eluted with 30%, 60%, and pure methanol on D-101 macroporous resin. The elution fractions were isolated and purified by silica gel column chromatography, thin layer chromatography, D-101 macroporous resin, semi-preparative high performance liquid chromatography(HPLC), and HPLC. The purified compounds were identified using one-dimensional and two-dimensional spectroscopy, high-resolution mass spectrometry, and other techniques. A total of 15 compounds were isolated and identified as 5-(4-hydroxy-3-methoxyphenyl)-3-(4-hydroxyphenyl)-N-methyl-3,6-dihydropyridine-2(1H)-one(1), 3,5-di(hydroxyphenyl)-N-methyl-3,6-dihydropyridine-2(1H)-one(2), protocatechualdehyde(3), protocatechuic acid(4), 3,4-dihydroxyacetophenone(5), syringic acid(6), vanillic acid(7), p-hydroxybenzoic acid(8),(2S)-4'-hydroxy-7-methoxyflavan(9), 2,4,6-trimethoxyacetophenone(10), N-trans-ferulic acid p-hydroxyphenylethylamine(11), N-cis-p-coumaroyltyramine(12), N-trans-p-coumaroyltyramine(13), piscidic acid(14), 5-hydroxymethylfurfural(15). Compounds 1 and 2 are new compounds with similar structure that have not been reported yet, named narcissus A and narcissus B. Compounds 8-13 were isolated and identified from the genus Narcissus for the first time, and compounds 14 and 15 were isolated from BNTC for the first time. Compounds 1 and 2 inhibited the release of NO from RAW264.7 cells induced by lipopolysaccharide(LPS)(P<0.001), with compound 1 having an IC_(50) value of(72.76±2.97) μmol·L~(-1) and compound 2 having an IC_(50) value of(63.59±0.96) μmol·L~(-1).
Mice ; Animals ; Narcissus/chemistry* ; Drugs, Chinese Herbal/isolation & purification* ; Plant Roots/chemistry* ; Chromatography, High Pressure Liquid ; Macrophages/immunology* ; RAW 264.7 Cells

This study aimed to investigate the effects of Zhiwei Fuwei Pills on mitochondrial apoptosis in the rat model of precancerous lesions of gastric cancer(PLGC) based on the microRNA-21(miRNA-21)/B-cell lymphoma-2(Bcl-2) signaling pathway. Eighty-five 5-week-old male SPF-grade SD rats were selected, of which 75 were fed with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) for multifactorial modeling, and the PLGC model was established after 26 weeks. The rats were randomly grouped as follows: model, folic acid(0.002 g·kg~(-1)), low-dose(0.42 g·kg~(-1)) Zhiwei Fuwei Pills, medium-dose(0.84 g·kg~(-1)) Zhiwei Fuwei Pills, and high-dose(1.67 g·kg~(-1)) Zhiwei Fuwei Pills, with 15 rats in each group. Additionally, 10 rats were assigned to a blank group and administrated with an equivalent volume of normal saline by gavage. After four weeks of continuous drug administration, the gastric mucosal tissue was collected. Hematoxylin-eosin(HE) staining was performed to reveal the pathological changes in the gastric mucosa. Terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL) was employed to detect apoptosis in gastric mucosal epithelial cells. RT-PCR was adopted to determine the mRNA levels of miRNA-21, phosphatase and tensin homolog(PTEN), Bcl-2, Bcl-2-associated X protein(Bax), and cysteinyl aspartate-specific protease 3(caspase-3). Western blot was employed to determine the protein levels of PTEN, Bcl-2, Bax, and caspase-3. Immunohistochemistry(IHC) was used to detect the positive expression of PTEN, Bcl-2, and Bax in the gastric mucosal tissue. Transmission electron microscopy(TEM) was employed to observe the morphological and structural changes in mitochondria. The results showed that compared with model group, the drug administration groups showed alleviated pathological changes, with increased apoptotic cells, down-regulated mRNA levels of miRNA-21 and Bcl-2, up-regulated mRNA and protein levels of PTEN, Bax, and caspase-3, and down-regulated protein level of Bcl-2. In addition, the drug administration groups exhibited mitochondrial swelling and rupture and reduction of cristae, which indicated mitochondrial apoptosis. These findings suggest that Zhiwei Fuwei Pills can effectively improve mitochondrial apoptosis in PLGC cells by regulating the miRNA-21/Bcl-2 signaling pathway.
Animals ; MicroRNAs/metabolism* ; Male ; Apoptosis/drug effects* ; Stomach Neoplasms/physiopathology* ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Rats ; Rats, Sprague-Dawley ; Drugs, Chinese Herbal/administration & dosage* ; Mitochondria/genetics* ; Signal Transduction/drug effects* ; Precancerous Conditions/drug therapy* ; Humans ; PTEN Phosphohydrolase/genetics*

This study aims to investigate the effect of Chaijin Jieyu Anshen Formula on the neuroinflammation of rats with insomnia complicated with depression through the regulation of triggering receptor expressed on myeloid cells 2(TREM2)/complement protein C1q signaling pathway. Rats were randomly divided into a normal group, a model group, a positive drug group, as well as a high, medium, and low-dose groups of Chaijin Jieyu Anshen Formula, with 10 rats in each group. Except for the normal group, the other groups were injected with p-chlorophenylalanine and exposed to chronic unpredictable mild stress to establish the rat model of insomnia complicated with depression. The sucrose preference experiment, open field experiment, and water maze test were performed to evaluate the depression in rats. Enzyme-linked immunosorbent assay was employed to detect serum 5-hydroxytryptamine(5-HT), dopamine(DA), and norepinephrine(NE) levels. Hematoxylin and eosin staining and Nissl staining were used to observe the damage in nucleus accumbens neurons. Western blot and immunofluorescence were performed to detect TREM2, C1q, postsynaptic density 95(PSD-95), and synaptophysin 1(SYN1) expressions in rat nucleus accumbens, respectively. Golgi-Cox staining was utilized to observe the synaptic spine density of nucleus accumbens neurons. The results show that, compared with the model group, Chaijin Jieyu Anshen Formula can significantly increase the sucrose preference as well as the distance and number of voluntary activities, shorten the immobility time in forced swimming test and the successful incubation period of positioning navigation, and prolong the stay time of space exploration in the target quadrant test. The serum 5-HT, DA, and NE contents in the model group are significantly lower than those in the normal group, with the above contents significantly increased after the intervention of Chaijin Jieyu Anshen Formula. In addition, Chaijin Jieyu Anshen Formula can alleviate pathological damages such as swelling and loose arrangement of tissue cells in the nucleus accumbens, while increasing the Nissl body numbers. Chaijin Jieyu Anshen Formula can improve synaptic damage in the nucleus accumbens and increase the synaptic spine density. Compared to the normal group, the expression of C1q protein was significantly higher in the model group, while the expression of TREM2 protein was significantly lower. Compared to the model group, the intervention with Chaijin Jieyu Anshen Formula significantly downregulated the expression of C1q protein and significantly upregulated the expression of TREM2. Compared with the model group, the PSD-95 and SYN1 fluorescence intensity is significantly increased in the groups receiving different doses of Chaijin Jieyu Anshen Formula. In summary, Chaijin Jieyu Anshen Formula can reduce the C1q protein expression, relieve the TREM2 inhibition, and promote the synapse-related proteins PSD-95 and SNY1 expression. Chaijin Jieyu Anshen Formula improves synaptic injury of the nucleus accumbens neurons, thereby treating insomnia complicated with depression.
Animals ; Male ; Rats ; Nucleus Accumbens/metabolism* ; Drugs, Chinese Herbal/administration & dosage* ; Depression/complications* ; Membrane Glycoproteins/genetics* ; Rats, Sprague-Dawley ; Sleep Initiation and Maintenance Disorders/complications* ; Neurons/metabolism* ; Receptors, Immunologic/genetics* ; Signal Transduction/drug effects* ; Synapses/metabolism*

The aim of this study was to investigate the contribution of lung zinc ions to pathogenesis of lung ischemia/reperfusion (I/R) injury in rats. Male Sprague Dawley (SD) rats were randomly divided into control group, lung I/R group (I/R group), lung I/R + low-dose zinc chloride group (LZnCl₂+I/R group), lung I/R + high-dose ZnCl₂ group (HZnCl₂+I/R group), lung I/R + medium-dose ZnCl₂ group (MZnCl₂+I/R group) and TPEN+MZnCl₂+I/R group (n = 8 in each group). Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the concentration of zinc ions in lung tissue. The degree of lung tissue injury was analyzed by observing HE staining, alveolar damage index, lung wet/dry weight ratio and lung tissue gross changes. TUNEL staining was used to detect cellular apoptosis in lung tissue. Western blot and RT-qPCR were used to determine the protein expression levels of caspase-3 and ZIP8, as well as the mRNA expression levels of zinc transporters (ZIP, ZNT) in lung tissue. The mitochondrial membrane potential (MMP) of lung tissue was detected by JC-1 MMP detection kit. The results showed that, compared with the control group, the lung tissue damage, lung wet/dry weight ratio and alveolar damage index were significantly increased in the I/R group. And in the lung tissue, the concentration of Zn²⁺ was markedly decreased, while the cleaved caspase-3/caspase-3 ratio and apoptotic levels were significantly increased. The expression levels of ZIP8 mRNA and protein were down-regulated significantly, while the mRNA expression of other zinc transporters remained unchanged. There was also a significant decrease in MMP. Compared with the I/R group, both MZnCl₂+I/R group and HZnCl₂+I/R group exhibited significantly reduced lung tissue injury, lung wet/dry weight ratio and alveolar damage index, increased Zn²⁺ concentration, decreased ratio of cleaved caspase-3/caspase-3 and apoptosis, and up-regulated expression levels of ZIP8 mRNA and protein. In addition, the MMP was significantly increased in the lung tissue. Zn²⁺ chelating agent TPEN reversed the above-mentioned protective effects of medium-dose ZnCl₂ on the lung tissue in the I/R group. The aforementioned results suggest that exogenous administration of ZnCl₂ can improve lung I/R injury in rats.
Animals ; Reperfusion Injury/pathology* ; Male ; Rats, Sprague-Dawley ; Rats ; Chlorides/administration & dosage* ; Lung/pathology* ; Zinc Compounds/administration & dosage* ; Apoptosis/drug effects* ; Caspase 3/metabolism* ; Cation Transport Proteins/metabolism*

ObjectiveObesity has been identified as one of the most important risk factors for cognitive dysfunction. Physical exercise can ameliorate learning and memory deficits by reversing synaptic plasticity in the hippocampus and cortex in diseases such as Alzheimer’s disease. In this study, we aimed to determine whether 8 weeks of treadmill exercise could alleviate hippocampus-dependent memory impairment in high-fat diet-induced obese mice and investigate the potential mechanisms involved. MethodsA total of sixty 6-week-old male C57BL/6 mice, weighing between 20-30 g, were randomly assigned to 3 distinct groups, each consisting of 20 mice. The groups were designated as follows: control (CON), high-fat diet (HFD), and high-fat diet with exercise (HFD-Ex). Prior to the initiation of the treadmill exercise protocol, the HFD and HFD-Ex groups were fed a high-fat diet (60% fat by kcal) for 20 weeks. The mice in the HFD-Ex group underwent treadmill exercise at a speed of 8 m/min for the first 10 min, followed by 12 m/min for the subsequent 50 min, totally 60 min of exercise at a 0° slope, 5 d per week, for 8 weeks. We employed Y-maze and novel object recognition tests to assess hippocampus-dependent memory and utilized immunofluorescence, Western blot, Golgi staining, and ELISA to analyze axon length, dendritic complexity, number of spines, the expression of c-fos, doublecortin (DCX), postsynaptic density-95 (PSD95), synaptophysin (Syn), interleukin-1β (IL-1β), and the number of major histocompatibility complex II (MHC-II) positive cells. ResultsMice with HFD-induced obesity exhibit hippocampus-dependent memory impairment, and treadmill exercise can prevent memory decline in these mice. The expression of DCX was significantly decreased in the HFD-induced obese mice compared to the control group (P<0.001). Treadmill exercise increased the expression of c-fos (P<0.001) and DCX (P=0.001) in the hippocampus of the HFD-induced obese mice. The axon length (P<0.001), dendritic complexity (P<0.001), the number of spines (P<0.001) and the expression of PSD95 (P<0.001) in the hippocampus were significantly decreased in the HFD-induced obese mice compared to the control group. Treadmill exercise increased the axon length (P=0.002), dendritic complexity(P<0.001), the number of spines (P<0.001) and the expression of PSD95 (P=0.001) of the hippocampus in the HFD-induced obese mice. Our study found a significant increase in MHC-II positive cells (P<0.001) and the concentration of IL-1β (P<0.001) in the hippocampus of HFD-induced obese mice compared to the control group. Treadmill exercise was found to reduce the number of MHC-II positive cells (P<0.001) and the concentration of IL-1β (P<0.001) in the hippocampus of obese mice induced by a HFD. ConclusionTreadmill exercise led to enhanced neurogenesis and neuroplasticity by increasing the axon length, dendritic complexity, dendritic spine numbers, and the expression of PSD95 and DCX, decreasing the number of MHC-II positive cells and neuroinflammation in HFD-induced obese mice. Therefore, we speculate that exercise may serve as a non-pharmacologic method that protects against HFD-induced hippocampus-dependent memory dysfunction by enhancing neuroplasticity and neurogenesis in the hippocampus of obese mice.

OBJECTIVE: This study aimed to explore the association between body mass index (BMI) and mortality based on the 10-year population-based multicenter prospective study. METHODS: A general population-based multicenter prospective study was conducted at four sites in rural China between 2013 and 2023. Multivariate Cox proportional hazards models and restricted cubic spline analyses were used to assess the association between BMI and mortality. Stratified analyses were performed based on the individual characteristics of the participants. RESULTS: Overall, 19,107 participants with a sum of 163,095 person-years were included and 1,910 participants died. The underweight (< 18.5 kg/m ²) presented an increase in all-cause mortality (adjusted hazards ratio [ aHR] = 2.00, 95% confidence interval [ CI]: 1.66-2.41), while overweight (≥ 24.0 to < 28.0 kg/m ²) and obesity (≥ 28.0 kg/m ²) presented a decrease with an aHR of 0.61 (95% CI: 0.52-0.73) and 0.51 (95% CI: 0.37-0.70), respectively. Overweight ( aHR = 0.76, 95% CI: 0.67-0.86) and mild obesity ( aHR = 0.72, 95% CI: 0.59-0.87) had a positive impact on mortality in people older than 60 years. All-cause mortality decreased rapidly until reaching a BMI of 25.7 kg/m ² ( aHR = 0.95, 95% CI: 0.92-0.98) and increased slightly above that value, indicating a U-shaped association. The beneficial impact of being overweight on mortality was robust in most subgroups and sensitivity analyses. CONCLUSION This study provides additional evidence that overweight and mild obesity may be inversely related to the risk of death in individuals older than 60 years. Therefore, it is essential to consider age differences when formulating health and weight management strategies.
Humans ; Body Mass Index ; China/epidemiology* ; Male ; Female ; Middle Aged ; Prospective Studies ; Rural Population/statistics & numerical data* ; Aged ; Follow-Up Studies ; Adult ; Mortality ; Cause of Death ; Obesity/mortality* ; Overweight/mortality*