1.Study on Reducing Hepatotoxicity and Retaining Anti-osteoporosis Activity of Psoraleae Fructus Though Salt Processing Based on Zebrafish
Yiqi LIU ; Xuan WANG ; Qiqi FAN ; Zehua CHANG ; Shuo FAN ; Na WANG ; Zheng LI ; Xinfang XU ; Chongjun ZHAO ; Xiangri LI
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(9):79-90
ObjectiveTo investigate the mechanism of salt processing of Psoraleae Fructus (PF) through modern analytical techniques and biotechnology, focusing on its effects related to hepatotoxicity and anti-osteoporosis activity. MethodsThe zebrafish model was utilized to evaluate the impact of PF and salt-processed Psoraleae Fructus (SPF) on the hepatotoxicity (using 134.17 , 178.89, 268.34 mg·L-1 as low, medium, and high dose groups of PF, 135.04, 180.06, 270.08 mg·L-1 as low, medium, and high dose groups of SPF, respectively) and anti-osteoporotic activity (using 33.54 , 67.08 and 134.17 mg·L-1 as low, medium, and high dose groups of PF, 33.76, 67.52, 135.04 mg·L-1 as low, medium, and high dose groups of SPF, respectively), which was using alizarin red skull staining of zebrafish as an indicator of different batches of PF. The specific dosage of a batch of PF was taken as an example. Then ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry(UPLC-Q-TOF-MS) analysis was employed to identify the chemical composition of PF before and after salt processing, and PCA, OPLS-DA, and independent sample t-test were used to elucidating the compositional changes associated with the effects of salt processing on hepatotoxicity and anti-osteoporosis activity. ResultsUnder specific conditions, PF induced notable hepatotoxicity in zebrafish while simultaneously demonstrating protective effect against prednisolone-induced osteoporosis. In comparison to PF, SPF showed alleviated hepatotoxicity while retaining significant anti-osteoporosis activity. UPLC-Q-TOF-MS analysis revealed that after salt processing, the overall chemical composition of PF showed a downward trend, with 69 components showing a decrease in content, represented by psoralen, and 13 components showing an increase, represented by 4′-O-methyl psoralen B. Further multivariate statistical analysis revealed 11 key differential components before and after salt processing of PF, including psoralen and bakuchiol. ConclusionSalt processing effectively diminishes hepatotoxicity without impairing therapeutic efficacy against osteoporosis of PF, which may be related to the compositional changes before and after salt processing of PF and provides key evidence to reveal the scientific significance of salt processing of PF.
2.Clinical Efficacy of Fengyintang Combined with Western Medicine in Treatment of Parkinson's Disease with Excessive Heat Generating Wind and Its Effects on TLR4 and Inflammatory Factor Levels in Peripheral Blood
Jingyi ZHANG ; Meiru CHANG ; Shouzhen LUO ; Wenlei LI ; Xinyu XU ; Jianhua LIN ; Yan ZHENG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(17):184-191
ObjectiveToll-like receptor 4 (TLR4), a receptor for pathogen-associated molecular patterns of innate immunity, is associated with neurodegenerative diseases. Interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α) as common pro-inflammatory cytokines and high-sensitivity C-reactive protein (hs-CRP) are related to inflammatory responses. This study evaluated the clinical efficacy and possible mechanisms of therapeutic effects of Fengyintang on early and mid-stage PD with excessive heat generating wind by observing the effects of Fengyintang on the serum levels of TLR4, IL-6, IL-1β, TNF-α, and hs-CRP in the patients with PD. MethodsSixty-eight PD patients who met the inclusion criteria were randomly assigned into the control group and the observation group (n=34). Both groups were treated with anti-PD Western medicine and the observation group was additionally treated with Fengyintang. Both groups were treated for 8 weeks. Before and after 8 weeks of treatment, the patients in the two groups were measured for their TCM symptom scores, International Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) score, Parkinson's Disease Non-Motor Symptom Scale (NMSS) score, Patient Assessment of Constipation Symptom (PAC-SYM) score, Pittsburgh Sleep Quality Index (PSQI), Hamilton Anxiety Scale (HAMA) score, Hamilton Depression Scale (HAMD) score, and changes in serum TLR4, IL-6, IL-1β, TNF-α, and hs-CRP levels. ResultsOne case in the control group was removed due to loss of visit, and a total of 67 PD patients (33 in the control group and 34 in the observation group) who met the criteria were included for analysis. After treatment, patients in the observation group showed decreases in scores of TCM symptoms, MDS-UPDRS, NMSS, PAC-SYM, PSQI, HAMA, and HAMD (P<0.05, P<0.01). Moreover, the observation group had lower scores of TCM symptoms, MDS-UPDRS, NMSS, PAC-SYM, PSQI, HAMA, and HAMD than the control group (P<0.05, P<0.01). The observation group showed higher efficacy in terms of TCM symptoms and MDS-UPDRS score than the control group (Z=-0.57, P<0.05). The overall response rate was higher in the observation group than in the control group (Z=-0.62, P<0.05, P<0.01). The serum TLR4, TNF-α, IL-1β, IL-6, and hs-CRP levels of the observation group were lower than those of the control group (P<0.05, P<0.01). ConclusionFengyintang combined with Western medicine can safely and effectively alleviate the clinical symptoms, reduce the levels of inflammatory factors, improve the quality of life, and delay the disease progression of PD patients by inhibiting peripheral TLR4 expression and thus suppressing the downstream inflammatory response.
3.Mechanistic Study on IRF7-mediated Regulation of Learning and Memory Function by Aerobic Exercise in Aged Mice
Min-Yan ZHENG ; Xiao-Han HUANG ; Chang-Ling WEI ; Yuan-Ting ZHANG ; Yu JIN ; Xue LI
Progress in Biochemistry and Biophysics 2026;53(9):2449-2461
ObjectiveTo explore the mechanism by which aerobic exercise improves hippocampal neuroinflammation and learning and memory ability in brain-aged mice via interferon regulatory factor 7 (IRF7). MethodsA total of 60 male specific pathogen-free (SPF) C57BL/6J mice were enrolled in the experiment, including 30 young mice (2 months old) and 30 naturally aging mice (12 months old). Young mice and old mice were respectively randomly assigned to four groups: young control group (group C, n=15), young exercise group (group CE, n=15), and aging control group (group A, n=15), aging exercise group (group AE, n=15). Mice in the exercise groups received an 8-week continuous treadmill aerobic exercise intervention, while control mice were kept under routine feeding without exercise intervention. After the intervention, Barnes maze and Y-maze behavioral tests were performed to comprehensively assess the learning and memory abilities of each group of mice. Transmission electron microscopy was used to observe the ultrastructural morphological changes of hippocampal synapses. Western blot assay was utilized to detect the protein expression and phosphorylation levels of Janus kinase 1 (JAK1), signal transducer and activator of transcription 1 (STAT1), as well as the expression of postsynaptic density protein 95 (PSD95). Immunofluorescence staining was applied to quantify the fluorescence intensity of ionized calcium-binding adapter molecule 1 (IBA1) in hippocampal tissues. The expression levels of inflammatory cytokines including interferon-α (IFN-α), interferon-β (IFN-β), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were measured by enzyme-linked immunosorbent assay (ELISA). Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the mRNA expression level of IRF7, and DNA methylation assay was further conducted to analyze the methylation level of the IRF7 gene in mouse hippocampus. ResultsAt the molecular level, compared with group C, the protein expression levels of JAK1, STAT1, p‑JAK1, and p‑STAT1 in group A were significantly increased (P<0.05), whereas PSD95 expression was decreased (P<0.05). ELISA assays showed that the levels of IFN‑α, IFN‑β, TNF‑α, and IL‑1β were significantly elevated in group A (P<0.001). RT‑PCR analysis revealed that, compared with group C, the mRNA expression of IRF7 in group A was markedly upregulated (P<0.000 1), while the CpG methylation rate of the IRF7 promoter was significantly reduced (P<0.05). In contrast, all the above parameters in the AE group showed improvements relative to those in group A. Immunofluorescence staining indicated positive IBA1 expression in the brain tissues of group A mice. Exercise intervention reversed these abnormal changes. ConclusionIn aged mice, aerobic exercise induces hypermethylation of the IRF7 promoter region, suppresses IRF7 expression and activation of the downstream IFN‑I/JAK1/STAT1 signaling pathway, accompanied by alleviated neuroinflammation, improved learning and memory, and ameliorated brain aging-related phenotypes.
4.Artificial intelligence in traditional Chinese medicine: from systems biological mechanism discovery, real-world clinical evidence inference to personalized clinical decision support.
Dengying YAN ; Qiguang ZHENG ; Kai CHANG ; Rui HUA ; Yiming LIU ; Jingyan XUE ; Zixin SHU ; Yunhui HU ; Pengcheng YANG ; Yu WEI ; Jidong LANG ; Haibin YU ; Xiaodong LI ; Runshun ZHANG ; Wenjia WANG ; Baoyan LIU ; Xuezhong ZHOU
Chinese Journal of Natural Medicines (English Ed.) 2025;23(11):1310-1328
Traditional Chinese medicine (TCM) represents a paradigmatic approach to personalized medicine, developed through the systematic accumulation and refinement of clinical empirical data over more than 2000 years, and now encompasses large-scale electronic medical records (EMR) and experimental molecular data. Artificial intelligence (AI) has demonstrated its utility in medicine through the development of various expert systems (e.g., MYCIN) since the 1970s. With the emergence of deep learning and large language models (LLMs), AI's potential in medicine shows considerable promise. Consequently, the integration of AI and TCM from both clinical and scientific perspectives presents a fundamental and promising research direction. This survey provides an insightful overview of TCM AI research, summarizing related research tasks from three perspectives: systems-level biological mechanism elucidation, real-world clinical evidence inference, and personalized clinical decision support. The review highlights representative AI methodologies alongside their applications in both TCM scientific inquiry and clinical practice. To critically assess the current state of the field, this work identifies major challenges and opportunities that constrain the development of robust research capabilities-particularly in the mechanistic understanding of TCM syndromes and herbal formulations, novel drug discovery, and the delivery of high-quality, patient-centered clinical care. The findings underscore that future advancements in AI-driven TCM research will rely on the development of high-quality, large-scale data repositories; the construction of comprehensive and domain-specific knowledge graphs (KGs); deeper insights into the biological mechanisms underpinning clinical efficacy; rigorous causal inference frameworks; and intelligent, personalized decision support systems.
Medicine, Chinese Traditional/methods*
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Artificial Intelligence
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Humans
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Precision Medicine
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Decision Support Systems, Clinical
5.Mechanistic insights into honey-boiled detoxification of ChuanWu: A study on alkaloid transformation and supramolecular aggregation.
Yu ZHENG ; Nina WEI ; Chang LU ; Weidong LI ; Xiaobin JIA ; Linwei CHEN ; Rui CHEN ; Zhipeng CHEN
Journal of Pharmaceutical Analysis 2025;15(9):101205-101205
ChuanWu (CW), the dried mother root of Aconitum carmichaelii Debx., is a well-known traditional Chinese medicine (TCM) recognized for its potent efficacy but inherent toxicity, primarily due to its alkaloid content. Traditional and modern detoxification methods for CW include proper processing, rational compatibility, and specialized decoction techniques, among which honey-boiled CW is particularly distinctive. However, research on the detoxification mechanism of honey-boiled CW remains limited. This study investigated this mechanism by analyzing alkaloid transformation and supramolecular aggregation. Honey-boiled and water-boiled CW preparations were compared. Ultra-high-performance liquid chromatography-tandem mass spectrometry was used to analyze CW alkaloids, specifically diester alkaloids (DDAs), monoester alkaloids (MDAs), and non-esterified diterpenoid alkaloids (NDAs). Transmission electron microscopy was employed to observe and identify supramolecular aggregates in the honey-boiled CW decoction. In vivo absorption of water-boiled, honey-boiled, and NADES-boiled CW was compared. Median lethal dose (LD50) tests assessed toxicity, including hepatotoxicity and nephrotoxicity. In vitro experiments evaluated the safety, anti-inflammatory, and analgesic effects of CW-medicated serum on RAW264.7 cells, with in vivo validation in mice. Results showed that honey promoted the conversion of highly toxic DDAs to less toxic MDAs and prevented MDAs from hydrolyzing into NDAs. Honey-boiled CW formed approximately 250 nm supramolecular aggregates that encapsulated MDAs, inhibiting their conversion to NDAs. These encapsulated MDAs acted as a stable delivery system with higher bioavailability than free benzoylmesaconine. Subsequent mouse experiments confirmed that honey-boiled CW significantly increased the LD50 of CW while reducing hepatotoxicity and nephrotoxicity. Additionally, honey-boiled CW significantly improved cell safety and enhanced anti-inflammatory and analgesic effects. Our findings reveal that honey-boiled CW exhibits a potent detoxification mechanism by influencing alkaloid transformation and facilitating the formation of supramolecular aggregates. This study lays the groundwork for developing detoxification or synergistic strategies within honey-boiled TCM.
6.Integrated-omics analysis defines subtypes of hepatocellular carcinoma based on circadian rhythm.
Xiao-Jie LI ; Le CHANG ; Yang MI ; Ge ZHANG ; Shan-Shan ZHU ; Yue-Xiao ZHANG ; Hao-Yu WANG ; Yi-Shuang LU ; Ye-Xuan PING ; Peng-Yuan ZHENG ; Xia XUE
Journal of Integrative Medicine 2025;23(4):445-456
OBJECTIVE:
Circadian rhythm disruption (CRD) is a risk factor that correlates with poor prognosis across multiple tumor types, including hepatocellular carcinoma (HCC). However, its mechanism remains unclear. This study aimed to define HCC subtypes based on CRD and explore their individual heterogeneity.
METHODS:
To quantify CRD, the HCC CRD score (HCCcrds) was developed. Using machine learning algorithms, we identified CRD module genes and defined CRD-related HCC subtypes in The Cancer Genome Atlas liver HCC cohort (n = 369), and the robustness of this method was validated. Furthermore, we used bioinformatics tools to investigate the cellular heterogeneity across these CRD subtypes.
RESULTS:
We defined three distinct HCC subtypes that exhibit significant heterogeneity in prognosis. The CRD-related subtype with high HCCcrds was significantly correlated with worse prognosis, higher pathological grade, and advanced clinical stages, while the CRD-related subtype with low HCCcrds had better clinical outcomes. We also identified novel biomarkers for each subtype, such as nicotinamide n-methyltransferase and myristoylated alanine-rich protein kinase C substrate-like 1.
CONCLUSION
We classify the HCC patients into three distinct groups based on circadian rhythm and identify their specific biomarkers. Within these groups greater HCCcrds was associated with worse prognosis. This approach has the potential to improve prediction of an individual's prognosis, guide precision treatments, and assist clinical decision making for HCC patients. Please cite this article as: Li XJ, Chang L, Mi Y, Zhang G, Zhu SS, Zhang YX, et al. Integrated-omics analysis defines subtypes of hepatocellular carcinoma based on circadian rhythm. J Integr Med. 2025; 23(4): 445-456.
Humans
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Carcinoma, Hepatocellular/pathology*
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Liver Neoplasms/pathology*
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Circadian Rhythm/genetics*
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Prognosis
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Male
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Female
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Biomarkers, Tumor/genetics*
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Middle Aged
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Machine Learning
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Computational Biology
7.Efficacy and Safety of Systemic Thrombolysis in the Treatment of Lower Extremity Fracture Complicated With Distal Deep Vein Thrombosis.
Shi-Qiang LIAO ; Shu-Ming SHI ; Qiang ZHANG ; Chuan-Yong LI ; Guang-Feng ZHENG ; Zhi-Chang PAN ; Jian-Jie RONG
Acta Academiae Medicinae Sinicae 2025;47(2):237-243
Objective To evaluate the efficacy and safety of systemic thrombolysis(ST)and standard anticoagulation(SA)in the treatment of lower extremity fracture complicated with distal deep vein thrombosis(DDVT).Methods We retrospectively analyzed the clinical data of 60 patients with lower extremity fracture complicated with DDVT treated from January 2021 to December 2023.When the lower limb venography indicated a calf thrombus burden score ≥3 points,a retrievable inferior vena cava filter(IVCF)was successfully placed in the healthy femoral vein before orthopedic surgery.The patients who received further anticoagulant or thrombolytic therapy after surgery were allocated into a ST group(n=30,urokinase ST and SA)and a SA group(n=30,only SA).The two groups were compared in terms of calf thrombus burden score,thrombus dissolution rate,IVCF placement time,IVCF retrieval rate,intercepted thrombi,hemoglobin level,platelet count,D-dimer level,and complications.Results There was no statistically significant difference in the calf thrombus burden score between the two groups before treatment(P=0.431).However,after treatment,the scores in both groups decreased(both P<0.001),with the ST group showing lower score than the SA group(P=0.002).The thrombus dissolution rate in the ST group was higher than that in the SA group(P<0.001).There was no statistically significant difference in the IVCF placement time between the two groups(P=0.359),and the IVCF retrieval rate was 100% in both groups.The ST group had fewer intercepted thrombi than the SA group(P=0.002).There was no statistically significant difference in hemoglobin level(P=0.238),platelet count(P=0.914),or D-dimer level(P=0.756)between the two groups before treatment.However,after treatment,both groups showed an increase in platelet count(both P<0.001)and a decrease in D-dimer level(both P<0.001).There was no statistically significant difference in the occurrence of complications between the two groups(P=0.704).Conclusions Both SA and ST demonstrate safety and efficacy in the treatment of lower extremity fractures complicated with DDVT,serving as valuable options for clinical application.Compared with SA,ST not only enhances the thrombus dissolution in the calf but also mitigates the risk of thrombosis associated with IVCF.
Humans
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Venous Thrombosis/therapy*
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Retrospective Studies
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Thrombolytic Therapy/methods*
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Male
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Female
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Middle Aged
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Fractures, Bone/complications*
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Lower Extremity/injuries*
;
Anticoagulants/therapeutic use*
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Aged
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Treatment Outcome
;
Adult
8.Mechanism of Aerobic Exercise in Delaying Brain Aging in Aging Mice by Regulating Tryptophan Metabolism
De-Man ZHANG ; Chang-Ling WEI ; Yuan-Ting ZHANG ; Yu JIN ; Xiao-Han HUANG ; Min-Yan ZHENG ; Xue LI
Progress in Biochemistry and Biophysics 2025;52(6):1362-1372
ObjectiveTo explore the molecular mechanism of aerobic exercise to improve hippocampal neuronal degeneration by regulating tryptophan metabolic pathway. Methods60 SPF-grade C57BL/6J male mice were divided into a young group (2 months old, n=30) and a senile group (12 months old, n=30), and each group was further divided into a control group (C/A group, n=15) and an exercise group (CE/AE group, n=15). An aerobic exercise program was used for 8 weeks. Learning memory ability was assessed by Y-maze, and anxiety-depression-like behavior was detected by absent field experiment. Hippocampal Trp levels were measured by GC-MS. Nissl staining was used to observe the number and morphology of hippocampal neurons, and electron microscopy was used to detect synaptic ultrastructure. ELISA was used to detect the levels of hippocampal Trp,5-HT, Kyn, KATs, KYNA, KMO, and QUIN; Western blot was used to analyze the activities of TPH2, IDO1, and TDO enzymes. ResultsGroup A mice showed significant decrease in learning and memory ability (P<0.05) and increase in anxiety and depressive behaviors (P<0.05); all of AE group showed significant improvement (P<0.05). Hippocampal Trp levels decreased in group A (P<0.05) and increased in AE group (P<0.05). Nidus vesicles were reduced and synaptic structures were degraded in group A (P<0.05), and both were significantly improved in group AE (P<0.05). The levels of Trp, 5-HT, KATs, and KYNA were decreased (P<0.05) and the levels of Kyn, KMO, and QUIN were increased (P<0.05) in group A. The activity of TPH2 was decreased (P<0.05), and the activities of IDO1 and TDO were increased (P<0.05). The AE group showed the opposite trend. ConclusionThe aging process significantly reduces the learning memory ability and increases the anxiety-depression-like behavior of mice, and leads to the reduction of the number of nidus vesicles and degenerative changes of synaptic structure in the hippocampus, whereas aerobic exercise not only effectively enhances the spatial learning memory ability and alleviates the anxiety-depression-like behavior of aging mice, but also improves the morphology and structure of neurons in hippocampal area, which may be achieved by the mechanism of regulating the tryptophan metabolic pathway.
9.Investigation of Effect of Different Drying Conditions on Appearance Characteristics and Internal Indicators of Pinelliae Rhizoma Based on Standardization
Suqing LIU ; Xueli ZHANG ; Jing ZHANG ; Cong YANG ; Changfu YANG ; Jun YU ; Bingpeng ZHENG ; Huiwu LI ; Yanhua JIANG ; Chang LIN
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(16):208-215
ObjectiveTo explore the effect of different drying conditions on the appearance and intrinsic quality indicators of Pinelliae Rhizoma for screening suitable drying conditions, so as to provide reference for its standardized production and quality evaluation. MethodsDifferent dried samples of Pinelliae Rhizoma were prepared by lime-assisted sweating method and intermittent drying method. Visual analysis was employed to measure the color brightness values(L*) of the surface, cross-section and powder of the samples, texture analyzer was used to determine the hardness of the samples under different drying conditions. The total starch content was calculated by measuring the contents of amylose and amylopectin in the samples with ultraviolet-visible spectroscopy. High performance liquid chromatography(HPLC) was used to determine the contents of seven nucleoside components(uracil, hypoxanthine, uridine, inosine, guanosine, β-thymidine and adenosine) in the samples. Pearson correlation analysis was conducted to explore the correlation between the external characteristics and intrinsic indicators of the different dried samples. Principal component analysis(PCA) was used to comprehensively rank the data of various indicators, and partial least squares-discriminant analysis(PLS-DA) was used to screen differential components with variable importance in the projection(VIP) value>1. Furthermore, the difference between the optimal drying condition for Pinelliae Rhizoma and the traditional sun-drying method was explored by independent samples t-test. ResultsWith the increase of temperature, the color of the intermittently dried samples gradually deepened, while their hardness gradually decreased. Concurrently, the contents of extract, total starch, uridine and adenosine exhibited an upward trend, whereas the contents of uracil, hypoxanthine and inosine displayed a downward trajectory. Compared with the intermittent drying group, the content of extract in the samples subjected to lime-assisted sweating increased. With the increase of lime dose, the hardness and the total content of nucleoside components in the samples showed a downward trend, while the total starch content showed an upward trend. Correlation analysis showed that the comprehensive score of L* was negatively correlated with the contents of uracil, hypoxanthine and inosine, and positively correlated with the contents of uridine, guanosine and adenosine. Hardness was negatively correlated with adenosine content, and positively correlated with the contents of inosine, uracil and hypoxanthine. Through comprehensive consideration and comprehensive score of principal components, the method of 5% lime-mixed sweating for 6 days emerged as the top-ranking approach. Except for the extract, the results of independent samples t-test showed that there was no significant difference between the 5% lime-mixed sweating for 6 days and the traditional sun-drying in terms of other content indicators. ConclusionThe whiteness and firmness of Pinelliae Rhizoma exhibit significant correlations with its chemical composition, while uridine, uracil, guanosine, adenosine and inosine are the key constituents responsible for the quality difference of Pinelliae Rhizoma under different drying conditions. The lime-assisted sweating method optimized in this study can be proposed as a viable alternative to the traditional sun-drying method. This method not only ensures the quality of the medicinal material but also effectively reduces the drying time and prevents mold contamination, which provides a valuable reference for the standardization of drying conditions and the establishment of quality evaluation criteria for Pinelliae Rhizoma.
10.Structural and Spatial Analysis of The Recognition Relationship Between Influenza A Virus Neuraminidase Antigenic Epitopes and Antibodies
Zheng ZHU ; Zheng-Shan CHEN ; Guan-Ying ZHANG ; Ting FANG ; Pu FAN ; Lei BI ; Yue CUI ; Ze-Ya LI ; Chun-Yi SU ; Xiang-Yang CHI ; Chang-Ming YU
Progress in Biochemistry and Biophysics 2025;52(4):957-969
ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

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