ObjectiveTo elucidate the underlying mechanism through which Zhuluan decoction suppresses excessive autophagy in human ovarian granulosa cells （KGN） and ameliorates premature ovarian insufficiency （POI） via the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin （mTOR） signaling pathway. MethodsThe optimal concentration of cyclophosphamide for inducing a POI model in KGN cells was identified via the cell counting kit-8 （CCK-8） assay. Subsequently， the impacts of varying concentrations of Zhuluan decoction-containing serum on the viability of the KGN cell model were assessed. After the optimal drug concentration was determined， KGN cells were categorized into the following groups： blank control （20% blank serum）， model （20% blank serum + 5 μmol·L^-1 cyclophosphamide）， Zhuluan decoction-containing serum （20% Zhuluan decoction-containing serum + 5 μmol·L^-1 cyclophosphamide）， autophagy inhibitor （20% blank serum + 5 μmol·L^-1 cyclophosphamide + 20 μmol·L^-1 chloroquine phosphate）， autophagy inhibitor + Zhuluan decoction-containing serum （20% Zhuluan decoction-containing serum + 5 μmol·L^-1 cyclophosphamide + 20 μmol·L^-1 chloroquine phosphate）， and estradiol valerate （20% estradiol valerate-containing serum + 5 μmol·L^-1 cyclophosphamide）. Following 48 hours of incubation， flow cytometry was utilized to measure the apoptosis rate of KGN cells in each group. Western blotting was employed to quantify the protein levels of PI3K， phosphorylated （p）-Akt， Akt， p-mTOR， and mTOR， along with the expression levels of autophagy-related proteins such as Beclin1， autophagy-related 5 homolog （ATG5）， and microtubule-associated protein 1 light chain 3 （LC3）， in each group. Additionally， monodansylcadaverine （MDC） staining was performed to evaluate the extent of autophagy in each group. ResultsIncubation of KGN cells with 5 μmol·L^-1 cyclophosphamide for 48 h successfully established a POI model， marked by a significant inhibition of KGN cell proliferation. Notably， the inhibitory effect of cyclophosphamide on KGN cell proliferation exhibited a positive correlation with its concentration. Zhuluan decoction-containing serum at 20% and 30% promoted cell proliferation and mitigated the inhibitory effect of cyclophosphamide on KGN cell proliferation， with comparable therapeutic efficacy observed at both concentrations. Compared with the blank control group， the model group displayed an elevated apoptosis rate （P<0.01）， reduced protein levels of PI3K， p-Akt， and p-mTOR （P<0.01）， increased protein levels of Beclin1， LC3， and ATG5 （P<0.01）， no significant alterations in the protein levels of Akt and mTOR， and an enhanced MDC autophagy fluorescence intensity （P<0.01）. In comparison to that the model group， the apoptosis rates in the blank control group， model group， Zhuluan decoction-containing serum group， autophagy inhibitor group， autophagy inhibitor + Zhuluan decoction-containing serum group， and estradiol valerate group all reduced （P<0.05， P<0.01）， with the most pronounced reduction observed in the autophagy inhibitor + Zhuluan decoction-containing serum group. The protein levels of PI3K， p-Akt， and p-mTOR were higher in other groups than in the model group （P<0.05， P<0.01）， being the highest in the autophagy inhibitor + Zhuluan decoctio-containing serum group （P<0.01）. The protein levels of Beclin1 and ATG5 were lower in other groups than in the model group （P<0.05， P<0.01）. The expression level of LC3 declined in the Zhuluan decoction-containing serum group and the estradiol valerate group （P<0.05， P<0.01）， while it decreased without statistical significance in the autophagy inhibitor group and the autophagy inhibitor + Zhuluan decoction-containing serum group. ConclusionZhuluan decoction may activate the PI3K/Akt/mTOR pathway to inhibit excessive autophagy and counteract the detrimental effects of cyclophosphamide on the KGN cell model， thus managing POI.

ObjectiveTo elucidate the underlying mechanism through which Zhuluan decoction suppresses excessive autophagy in human ovarian granulosa cells （KGN） and ameliorates premature ovarian insufficiency （POI） via the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin （mTOR） signaling pathway. MethodsThe optimal concentration of cyclophosphamide for inducing a POI model in KGN cells was identified via the cell counting kit-8 （CCK-8） assay. Subsequently， the impacts of varying concentrations of Zhuluan decoction-containing serum on the viability of the KGN cell model were assessed. After the optimal drug concentration was determined， KGN cells were categorized into the following groups： blank control （20% blank serum）， model （20% blank serum + 5 μmol·L^-1 cyclophosphamide）， Zhuluan decoction-containing serum （20% Zhuluan decoction-containing serum + 5 μmol·L^-1 cyclophosphamide）， autophagy inhibitor （20% blank serum + 5 μmol·L^-1 cyclophosphamide + 20 μmol·L^-1 chloroquine phosphate）， autophagy inhibitor + Zhuluan decoction-containing serum （20% Zhuluan decoction-containing serum + 5 μmol·L^-1 cyclophosphamide + 20 μmol·L^-1 chloroquine phosphate）， and estradiol valerate （20% estradiol valerate-containing serum + 5 μmol·L^-1 cyclophosphamide）. Following 48 hours of incubation， flow cytometry was utilized to measure the apoptosis rate of KGN cells in each group. Western blotting was employed to quantify the protein levels of PI3K， phosphorylated （p）-Akt， Akt， p-mTOR， and mTOR， along with the expression levels of autophagy-related proteins such as Beclin1， autophagy-related 5 homolog （ATG5）， and microtubule-associated protein 1 light chain 3 （LC3）， in each group. Additionally， monodansylcadaverine （MDC） staining was performed to evaluate the extent of autophagy in each group. ResultsIncubation of KGN cells with 5 μmol·L^-1 cyclophosphamide for 48 h successfully established a POI model， marked by a significant inhibition of KGN cell proliferation. Notably， the inhibitory effect of cyclophosphamide on KGN cell proliferation exhibited a positive correlation with its concentration. Zhuluan decoction-containing serum at 20% and 30% promoted cell proliferation and mitigated the inhibitory effect of cyclophosphamide on KGN cell proliferation， with comparable therapeutic efficacy observed at both concentrations. Compared with the blank control group， the model group displayed an elevated apoptosis rate （P<0.01）， reduced protein levels of PI3K， p-Akt， and p-mTOR （P<0.01）， increased protein levels of Beclin1， LC3， and ATG5 （P<0.01）， no significant alterations in the protein levels of Akt and mTOR， and an enhanced MDC autophagy fluorescence intensity （P<0.01）. In comparison to that the model group， the apoptosis rates in the blank control group， model group， Zhuluan decoction-containing serum group， autophagy inhibitor group， autophagy inhibitor + Zhuluan decoction-containing serum group， and estradiol valerate group all reduced （P<0.05， P<0.01）， with the most pronounced reduction observed in the autophagy inhibitor + Zhuluan decoction-containing serum group. The protein levels of PI3K， p-Akt， and p-mTOR were higher in other groups than in the model group （P<0.05， P<0.01）， being the highest in the autophagy inhibitor + Zhuluan decoctio-containing serum group （P<0.01）. The protein levels of Beclin1 and ATG5 were lower in other groups than in the model group （P<0.05， P<0.01）. The expression level of LC3 declined in the Zhuluan decoction-containing serum group and the estradiol valerate group （P<0.05， P<0.01）， while it decreased without statistical significance in the autophagy inhibitor group and the autophagy inhibitor + Zhuluan decoction-containing serum group. ConclusionZhuluan decoction may activate the PI3K/Akt/mTOR pathway to inhibit excessive autophagy and counteract the detrimental effects of cyclophosphamide on the KGN cell model， thus managing POI.

ObjectiveTo investigate the material basis of the pathogenesis of cerebral ischemic injury with blood stasis and toxin syndrome and to explore the protective effects of Huayu Jiedu prescription （HYJDP） on neutrophil extracellular trap-related cell death （NETosis） in cerebral ischemic injury following acute cerebral infarction. MethodsSeventy-two Sprague-Dawley （SD） rats were randomly divided into six groups （n=12 per group）： sham operation （Sham） group， blood stasis and toxin model （Model） group， low-， medium-， and high-dose HYJDP groups （HYJDP-L， HYJDP-M， and HYJDP-H； 9， 18， and 36 g·kg^-1， respectively）， and butylphthalide （NBP） group （0.06 g·kg^-1）. Except for the Sham group， rats in all other groups were subjected to carrageenan/dry yeast combined with a modified intraluminal filament method to establish a focal cerebral ischemia model of the middle cerebral artery with blood stasis and toxin syndrome. Neurological function was evaluated at 24 h after modeling using the Zea-Longa neurological deficit score. Cerebral infarction rate was assessed by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Pathological morphology of brain tissue was observed using hematoxylin-eosin （HE） staining. Enzyme-linked immunosorbent assay （ELISA） was used to determine serum levels of interleukin-8 （IL-8）， myeloperoxidase-DNA complexes （MPO-DNA）， and citrullinated histone H3 （CitH3）. Protein expression of phosphorylated phosphatidylinositol 3-kinase （p-PI3K）， protein kinase B （p-Akt）， mammalian target of rapamycin （p-mTOR）， sequestosome 1 （p62）， and CitH3 in brain tissue was detected by Western blot. Immunofluorescence （IF） was used to detect the expression of neutrophil-specific marker Ly6G， CitH3， and neuron-specific nuclear protein （NeuN） in brain tissue. ResultsCompared with the Sham group， neurological deficit scores and cerebral infarction rates in the model group were significantly increased （P<0.01 for both）. HE staining showed varying degrees of neuronal degeneration and necrosis， characterized by blurred neuronal structures， nuclear pyknosis and fragmentation， cytoplasmic dissolution into a vacuolated reticular pattern， and mild glial cell proliferation. ELISA results showed that serum levels of IL-8， MPO-DNA， and CitH3 were significantly increased （P<0.01）. Western blot analysis demonstrated decreased expression of p-PI3K， p-Akt， p-mTOR， and p62， while CitH3 expression was significantly increased （P<0.01）. IF results showed an increased number of NETs⁺ cells and a significant decrease in NeuN⁺ cells （P<0.01）. Compared with the Model group， neurological deficit scores in the HYJDP-H group were significantly decreased （P<0.05）， and cerebral infarction rates in the HYJDP-H and NBP groups were significantly reduced （P<0.01）. HE staining showed that brain tissue damage was markedly alleviated in the HYJDP-H group. ELISA results showed that levels of IL-8， MPO-DNA， and CitH3 were significantly decreased in the HYJDP-M， HYJDP-H， and NBP groups （P<0.01）. Western blot analysis showed that expression of p-PI3K， p-Akt， p-mTOR， and p62 was significantly increased in the HYJDP-H and NBP groups， while CitH3 expression was significantly reduced in all drug intervention groups （P<0.01）. IF results showed that the number of NETs⁺ cells was significantly decreased and the number of NeuN⁺ cells was significantly increased in all drug intervention groups （P<0.01）. ConclusionNETs may be the material basis of the pathogenesis of cerebral ischemic injury characterized by blood stasis and toxin. HYJDP can regulate the PI3K/Akt/mTOR signaling pathway， reduce the release of pro-inflammatory mediators and NETosis-related products， alleviate cerebral ischemic injury caused by autophagy-dependent NETosis， and thereby exert a neuroprotective effect.

ObjectiveThis paper aims to observe the protective effect of Huamoyan granules on knee osteoarthritis （KOA） and explore whether its protective effect is oriented toward an anti-inflammatory direction by regulation of macrophage polarization， which can effectively inhibit the progression of pathological inflammatory response， reduce the release of inflammatory pain mediators， and downregulate the protein expression level of transient receptor potential vanilloid 1 （TRPV1）， so as to provide experimental evidence for its clinical application and investigate its action mechanism. MethodsAfter adaptive feeding， Sprague-Dawley （SD） rats were randomly divided into six groups： sham group， model group， celecoxib group， and high， medium， and low-dose synovitis granule groups （9.6， 4.8， 2.4 g·kg^-1）. The administration dose of celecoxib capsules was 20 mg·kg^-1. There were 10 rats in the sham group and 12 rats in the model group and each administration group. A KOA animal model was established by means of intra-articular injection of sodium iodoacetate into the knee joint. From the 10^th day of the experiment， each administration group was given intragastric administration at a dose of 10 mL·kg^-1 for 4 weeks. General conditions of rats in each group were assessed daily. The pressure pain threshold （PPT） to mechanical stimulation and joint diameter were recorded. X-ray examination was performed on the right knee joints of rats for imaging analysis. Enzyme linked immunosorbent assay （ELISA） was performed to detect the tumor necrosis factor-α （TNF-α）， serum interleukin-1β （IL-1β）， and other pro-inflammatory cytokines in rat serum samples， as well as the expression levels of neurogenic inflammatory mediators such as nerve growth factor （NGF） and calcitonin gene-related peptide （CGRP）. Histopathological changes in the knee joint synovial tissues were examined by hematoxylineosin （HE） staining. Safranin O-fast green staining was performed to observe and evaluate the degree of knee cartilage lesions. Western blot was employed to quantitatively analyze TRPV1， p38 mitogen-activated protein kinase （p38 MAPK）， and phosphorylated （p）-p38 MAPK in rat knee synovial tissues. Immunofluorescence （IF） was used to measure and assess M1/M2 macrophage polarization. ResultsCompared with those in the sham group， the circumference and joint diameter of the right knee were markedly enlarged in the model group （P<0.01）， while PPTs of rats showed a significant reduction （P<0.01）. The contents of IL-1β， TNF-α， CGRP， and NGF in rats' serum were significantly elevated （P<0.01）， and the synovial Krenn score was increased （P<0.01）. The Mankin score of cartilage tissue was increased （P<0.01）， and the protein expressions of TRPV1 and p-p38 MAPK/p38 MAPK were significantly upregulated （P<0.01）. The experimental intervention significantly reduced the proportion of pro-inflammatory M1 macrophages in the total macrophage population （P<0.01）， and the percentage of M2 macrophages was decreased （P<0.01）. The M1/M2 macrophage ratio was significantly elevated （P<0.01）. Knee joint diameters of all dose groups of Huamoyan granules and the celecoxib group were reduced （P<0.01） compared with those of the model group， and the PPT recovery speeds in the high and medium-dose groups of Huamoyan granules were more obvious （P<0.05）. The contents of IL-1β， CGRP， and NGF in the rats' serum in all administration groups were significantly reduced （P<0.05， P<0.01）， and the content of TNF-α in rats' serum was significantly reduced （P<0.01）. All dose groups of Huamoyan granules demonstrated significant reductions in both synovial Krenn score （P<0.05， P<0.01） and protein expression of TRPV1 and p-p38 MAPK/p38 MAPK in rats' synovial tissues （P<0.01）. The percentage of M1 macrophages in the synovial tissues of the celecoxib group and all dose groups of Huamoyan granules was decreased （P<0.01）. The percentage of M2 macrophages was increased （P<0.05）， and the M1/M2 ratio was decreased （P<0.01）. ConclusionHuamoyan granules can alleviate the inflammatory response of KOA， reduce the release of inflammatory pain mediators， and downregulate TRPV1 protein expression by regulating macrophage polarization. Its mechanism may be related to the TRPV1/p38 MAPK signaling pathway， thereby achieving the effect of improving peripheral pain hypersensitivity in KOA.

ObjectiveTo investigate the association between metabolic associated fatty liver disease （MAFLD） and the risk of atherosclerotic cardiovascular disease （ASCVD）， and to provide data support for the prevention and treatment of such metabolic-associated diseases in clinical practice. MethodsAn observation cohort was established for the workers of Kailuan who underwent physical examination for the first time from June 2006 to October 2007 and had complete liver assessment data， without the history of malignant tumor， MAFLD or ASCVD. According to the presence or absence of MAFLD， the patients were divided into non-MAFLD group with 67 565 patients and MAFLD group with 29 004 patients， and according to the presence or absence of ASCVD， the patients were divided into non-ASCVD group with 69 141 patients and ASCVD group with 481 patients. The group t-test or the Wilcoxon rank-sum test was used for comparison of continuous data between the two groups. The χ² test was used for comparison of categorical data between the two groups. The life-table method was used to calculate the cumulative incidence rates of new-onset ASCVD and MAFLD； the Kaplan-Meier method was used to plot the survival curves of the cumulative incidence rates of ASCVD in the MAFLD group and the non-MAFLD group and the cumulative incidence rates of MAFLD in the ASCVD group and the non-ASCVD group， and the log-rank test was used for comparison of cumulative incidence rates between two groups. A multivariate Cox proportional-hazards regression model analysis was used to investigate the impact of MAFLD on the risk of ASCVD and the impact of ASCVD on the risk of MAFLD. ResultsCompared with the non-MAFLD group， the MAFLD group had significantly higher levels of body mass index （BMI）， waist circumference， systolic blood pressure （SBP）， diastolic blood pressure （DBP）， resting heart rate， alanine aminotransferase， uric acid （UA）， fasting blood glucose （FBG）， triglyceride （TG）， total cholesterol， low-density lipoprotein cholesterol， and high sensitivity C-reactive protein （hs-CRP）， as well as significanty lower levels of estimated glomerular filtration rate （eGFR） and high-density lipoprotein cholesterol （all P <0.05）. Compared with the non-ASCVD group， the ASCVD group had significantly higher levels of BMI， waist circumference， SBP， DBP， UA， FBG， TG， and hs-CRP and a significantly lower level of eGFR （all P<0.05）. The incidence rate of new-onset ASCVD continued to increase over time in the MAFLD group and the non-MAFLD group， while the incidence rate of new-onset MAFLD firstly increased and then remained stable over time in the ASCVD group and the non-ASCVD group. There were 4 263 cases （14.70%） of new-osnet ASCVD in the MAFLD group， with an incidence density of 12.90 per 1 000 person-years， while there were 6 529 cases （9.66%） of new-osnet ASCVD in the non-MAFLD group， with an incidence density of 8.24 per 1 000 person-years， and there were significant differences in the incidence density and cumulative incidence rate of ASCVD between the two groups （χ²=519.09 and 531.80， both P<0.05）. There were 148 cases （30.77%） of new-onset MAFLD in the ASCVD group， with an incidence density of 40.10 per 1 000 person-years， while there were 32 194 cases （46.56%） of new-onset MAFLD in the non-ASCVD group， with an incidence density of 57.59 per 1 000 person-years， and there were significant differences in the incidence density and cumulative incidence rate of MAFLD between the two groups （χ²=19.29 and 30.78， both P<0.05）. The corrected multivariate Cox proportional-hazards regression model analysis showed that MAFLD was a risk factor for new-onset ASCVD （hazard ratio ［HR］=1.11， 95% confidence interval ［CI］： 1.06 — 1.16， P<0.001）， while ASCVD was a protective factor against new-onset MAFLD （HR=0.72， 95%CI： 0.61 — 0.85， P<0.001）. ConclusionThere is a significant association between MAFLD and ASCVD， with an increase in the risk of ASCVD in the MAFLD population and a reduction in the risk of MAFLD in the ASCVD population.

Objective: To investigate the effect of intraarticular hemorrhage on extending knee joint contracture model in rats . Methods: 18 mature male SD rats were divided into 3 groups by random number table method . The control group ( group C) was not immobilized and was killed after 4 weeks of feeding . In the simple fixation group( M1 group) , the left lower limb knee joint was immobilized in straight position for 4 weeks . The blood fixationgroup (M2 group) was injected into the knee cavity with body blood and immobilized in a straight position for 4 weeks . The knee joint motion of each group was measured by the joint motion measuring instrument under a stand⁃ard torque . The contracture degree was calculated by the joint range of motion of the knee joint before and after muscles separation . HE staining and Masson staining were used to detect the number of cells and collagen deposi⁃tion in the anterior joint capsule . The protein expressions of transforming growth factor 1 (TGF⁃ β1) , wingless⁃type MMTV integration site family , member 1 ( Wnt1) and beta⁃catenin ( β⁃catenin) in the anterior articular capsule were detected by Western blotting . Results: Compared with group C , total knee contracture and arthrogenic con⁃tracture of rats in M1 and M2 groups increased , and the difference was statistically significant (P < 0. 05) . At the same time , the degree of total contracture and arthrogenic contracture in M2 group was higher than that in M1 group , and the difference was statistically significant (P < 0. 05) . Compared with group C , the number of anterior joint capsule cells and collagen deposition in M1 and M2 groups increased , and the difference was statistically sig⁃group were higher than those in M1 group , and the difference was statistically significant (P < 0. 05) . Compared with group C , the protein expressions of TGF⁃ β1 , Wnt1 and β ⁃catenin in the anterior articular capsule of rats in M1 expressions of TGF⁃ β1 , Wnt1 and β ⁃catenin in the anterior articular capsule of the knee joint in M2 group were sig⁃nificantly higher than those in M1 group , with statistical significance (P < 0. 05) . Conclusion Joint immobiliza⁃ tion can lead to joint contracture , and joint bleeding aggravates the degree of joint capsule fibrosis induced by im⁃mobilization .

Objective To establish a portable gas chromatography-mass spectrometry (GC-MS) method for determining carbon disulfide in workplace air. Methods Samples were collected using the built-in Tenax GR adsorption tube in the portable GC-MS, followed by thermal desorption. The analytes were separated on a DB-1 chromatographic column and detected by a 3D ion trap mass spectrometer, with 1,3,5-tris(trifluoromethyl)benzene used as the internal standard. Qualitative analysis was based on retention time and characteristic ions, and quantitative analysis was performed using the internal standard method. Results The method showed a linear range of 0.034-0.340 mg/m³ with a correlation coefficient of 0.999 4 using the adsorption tube enrichment mode. The detection limit was 0.007 mg/m³, and the lower limit of quantification was 0.022 mg/m³. The average recovery ranged from 97.5% to 104.0%. The within-run and between-run relative standard deviation was 2.7%-10.4% and 8.8%-14.8%, respectively. Conclusion A rapid, green, highly sensitive, and interference-resistant on-site detection method was established. As a supplement to existing national standard methods, this method is suitable for real-time monitoring of carbon disulfide in workplace air and for occupational exposure risk assessment.

Background: Influenza A viruses (IAVs) are the major pathogens associated with respiratory infections which can result in extensive pathological damage in lungs and serious complications. Isorhamnetin, an abundant natural flavonoid in fruits and medicinal plants, has recently been shown to have strong antioxidative, anti-inflammatory, and antiviral effects. Objective: This study investigated the pharmacological effects of isorhamnetin on viral pneumonia and explored the underlying mechanisms by in vivo and in vitro experiments. Materials and methods: In the present study, the protective effect of isorhamnetin against IAV was evaluated by the cytopathogenic effect assay, cell counting kit-8 assay, real-time polymerase chain reaction, and immunofluorescence assay in vitro. Then the pathological damage associated with pneumonia was examined by calculating the pulmonary index and performing micro-CT and hematoxylin-eosin staining in vivo. Thereafter, the related protein or gene levels of factors in the mitogen-activated protein kinase (MAPK) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathways were determined by Western blot and immunofluorescence staining. Results: Isorhamnetin exerted significant anti-influenza effects and inhibited the expression of viral RNA in A549 cells, counteracting oxidative stress and apoptosis by suppressing the production of reactive oxygen species and caspase-3. The in vivo experiment results showed that isorhamnetin (20 and 40 mg/kg) caused a significant decrease in the pulmonary index, ameliorated pathological damage in the lung tissue, decreased viral load and NA activity, and reduced cytokines and nuclear factors. Furthermore, isorhamnetin could counteract the B cell lymphoma-2/B cell lymphoma-2–associated X protein (Bax) imbalance induced by PR8, suppress activation of the MAPK pathway, and upregulate the expression of Nrf2 and HO-1. Conclusions: Isorhamnetin can protect against viral pneumonia by activating the Nrf2/HO-1 pathway and suppressing the MAPK path-way. This study deciphers the pharmacological mechanism of isorhamnetin in alleviating pathological damage in viral pneumonia and provides rationale for the application of isorhamnetin in influenza treatment.

Background: Influenza A viruses (IAVs) are the major pathogens associated with respiratory infections which can result in extensive pathological damage in lungs and serious complications. Isorhamnetin, an abundant natural flavonoid in fruits and medicinal plants, has recently been shown to have strong antioxidative, anti-inflammatory, and antiviral effects. Objective: This study investigated the pharmacological effects of isorhamnetin on viral pneumonia and explored the underlying mechanisms by in vivo and in vitro experiments. Materials and methods: In the present study, the protective effect of isorhamnetin against IAV was evaluated by the cytopathogenic effect assay, cell counting kit-8 assay, real-time polymerase chain reaction, and immunofluorescence assay in vitro. Then the pathological damage associated with pneumonia was examined by calculating the pulmonary index and performing micro-CT and hematoxylin-eosin staining in vivo. Thereafter, the related protein or gene levels of factors in the mitogen-activated protein kinase (MAPK) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathways were determined by Western blot and immunofluorescence staining. Results: Isorhamnetin exerted significant anti-influenza effects and inhibited the expression of viral RNA in A549 cells, counteracting oxidative stress and apoptosis by suppressing the production of reactive oxygen species and caspase-3. The in vivo experiment results showed that isorhamnetin (20 and 40 mg/kg) caused a significant decrease in the pulmonary index, ameliorated pathological damage in the lung tissue, decreased viral load and NA activity, and reduced cytokines and nuclear factors. Furthermore, isorhamnetin could counteract the B cell lymphoma-2/B cell lymphoma-2–associated X protein (Bax) imbalance induced by PR8, suppress activation of the MAPK pathway, and upregulate the expression of Nrf2 and HO-1. Conclusions: Isorhamnetin can protect against viral pneumonia by activating the Nrf2/HO-1 pathway and suppressing the MAPK path-way. This study deciphers the pharmacological mechanism of isorhamnetin in alleviating pathological damage in viral pneumonia and provides rationale for the application of isorhamnetin in influenza treatment.

Background: Influenza A viruses (IAVs) are the major pathogens associated with respiratory infections which can result in extensive pathological damage in lungs and serious complications. Isorhamnetin, an abundant natural flavonoid in fruits and medicinal plants, has recently been shown to have strong antioxidative, anti-inflammatory, and antiviral effects. Objective: This study investigated the pharmacological effects of isorhamnetin on viral pneumonia and explored the underlying mechanisms by in vivo and in vitro experiments. Materials and methods: In the present study, the protective effect of isorhamnetin against IAV was evaluated by the cytopathogenic effect assay, cell counting kit-8 assay, real-time polymerase chain reaction, and immunofluorescence assay in vitro. Then the pathological damage associated with pneumonia was examined by calculating the pulmonary index and performing micro-CT and hematoxylin-eosin staining in vivo. Thereafter, the related protein or gene levels of factors in the mitogen-activated protein kinase (MAPK) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathways were determined by Western blot and immunofluorescence staining. Results: Isorhamnetin exerted significant anti-influenza effects and inhibited the expression of viral RNA in A549 cells, counteracting oxidative stress and apoptosis by suppressing the production of reactive oxygen species and caspase-3. The in vivo experiment results showed that isorhamnetin (20 and 40 mg/kg) caused a significant decrease in the pulmonary index, ameliorated pathological damage in the lung tissue, decreased viral load and NA activity, and reduced cytokines and nuclear factors. Furthermore, isorhamnetin could counteract the B cell lymphoma-2/B cell lymphoma-2–associated X protein (Bax) imbalance induced by PR8, suppress activation of the MAPK pathway, and upregulate the expression of Nrf2 and HO-1. Conclusions: Isorhamnetin can protect against viral pneumonia by activating the Nrf2/HO-1 pathway and suppressing the MAPK path-way. This study deciphers the pharmacological mechanism of isorhamnetin in alleviating pathological damage in viral pneumonia and provides rationale for the application of isorhamnetin in influenza treatment.