For quantitative analysis of related substances in TSD-1 active pharmaceutical ingredient, structures of prepared impurities were confirmed by NMR and UHPLC-MS, and a high performance liquid chromatographic method was established to determine the related substances in TSD-1. The analytical column was an Agilent ZORBAX Eclipe XDB-C8 (250 mm × 4.6 mm, 5 µm). The mobile phase A was 50 mmol·L^-1 ammonium acetate solution (adjusted pH to 5.8 with acetic acid) and the mobile phase B was acetonitrile. The whole run was carried out by gradient elution at a flow rate of 1.0 mL·min^-1. The detection wavelength was set at 240 nm and the column temperature was 30 ℃. The resolutions among peaks of TSD-1, impurity A, impurity B, TSD-D, and TSD-F were good. The calibration curves (n = 7) of TSD-1, impurity A, impurity B, TSD-D and TSD-F were linear in their respective weight ranges of 0.242-48.4 µg·mL^-1 (r = 1.000 0), 0.244-9.75 µg·mL^-1 (r = 0.999 9), 0.244-4.80 µg·mL^-1 (r = 0.999 9), 0.254-1.02 µg·mL^-1 (r = 0.999 9), and 0.247-0.987 µg·mL^-1 (r = 0.999 9). The lower limits of quantitation were 0.244, 0.244, 0.254, and 0.247 µg·mL^-1 for impurity A, impurity B, TSD-D, and TSD-F, respectively, and the average recovery of each impurity ranged from 99.08% to 103.00% with high accuracy. TSD-D and TSD-F were not detected in the three batches of TSD-1 active pharmaceutical ingredients, and impurity A and impurity B were not detected beyond the limit. The established HPLC method is simple, accurate, and suitable for determination of related substances of TSD-1, which can provide a valuable reference for the subsequent development of TSD-1.

With the acceleration of the aging process of our country's population, the impact of aging-related diseases - Alzheimer's disease (AD) on society and families has become increasingly prominent. AD is caused by multiple mechanisms, and the pathogenesis has not been fully elucidated. Most of the clinical treatments are single therapy, which mainly focuses on improving symptoms and are difficult to reverse the disease process. Therefore, the development of drugs that can both improve symptoms and reverse the disease process is extremely urgent in clinical. Increasing number of studies has shown that traditional Chinese medicine plays an important role in the prevention and treatment of AD. The natural products have many advantages, such as novel structures, multiple targets and diverse activities, which can be used as an important source of leading compounds for the treatment of AD. The review summarizes the main clinical treatment methods and the research progress of natural ingredients in traditional Chinese medicine, and provides a reference for the follow-up clinical treatment of AD combined with the advantages of traditional Chinese medicine treatment.

Alzheimer's disease (AD) and other aging-related diseases have become an important public health issue in China. However, current clinical drugs have failed to reverse the pathological process of AD. The holistic approach of traditional Chinese medicine offers advantages in improving cognitive function in AD through multiple molecular pathways, and may have potential for preventing AD. This paper summarizes the effects of classical traditional Chinese medicine and its active components in the improvement of AD-related cognitive dysfunction and describes the functional targets and related molecular mechanisms. This may have significance for the prevention and treatment of AD through multi-target intervention.

Cell senescence is characterized by permanent cell cycle arrest, accompanied by the changes in cell metabolism and epigenetic regulation. Alzheimer's disease (AD) is a common neurodegenerative disease, with the main symptoms of memory loss and cognitive impairment. A large number of studies have shown that the senescence of central nervous system cells such as astrocytes and microglia is closely related to the occurrence of AD. Inhibition of brain cell senescence is expected to provide new ideas and therapeutic strategies for the prevention and treatment of AD. This paper reviews the potential roles and mechanisms of senescence of brain cells in AD, and interaction effects among brain cells. This review will provide a new direction for the study of pathological mechanism of AD and the development of anti-AD drugs.

The COVID-19 outbreak has drawn attention to viral infectious diseases once again, and the development of antiviral drugs for both known and potentially emerging viruses is of great significance. In recent years, peptides and protein drugs are becoming a hot spot in the field of antiviral drug research and development. Phage display technology, as a powerful tool for screening peptides and protein drugs, has been increasingly concerned in the academic and industrial fields. The present review introduced the basic principle of phage display technology, summarized phage display libraries often used in antiviral drug discovery and their applications, discussed the challenges and future direction of antiviral drug research and development based on phage display technology.

Peptide drugs exhibit an irreplaceable role in clinics due to their high specificity, efficiency and low toxicity. At present, more than 80 peptide drugs have been approved for marketing with global sales exceeding $50 billion in 2019. However, with large molecular weights, high hydrophilicity and instability in digestive tract, oral peptide drugs encounter substantial physiological barriers leading to low oral bioavailability. Therefore, peptide drugs are mostly administered by parenteral routes. Although parenteral delivery of peptide drugs achieves high bioavailability, this is associated with inconvenience and discomfort, even causing severe side effects compared with the oral route possessing a high degree of patient compliance. Therefore, numerous studies concentrate on novel strategies to improve the oral bioavailability of peptide drugs. Some delivery technologies such as Eligen™ and Axcess™ have been successfully applied to the oral dosage form of therapeutic peptides and have accelerated relevant oral formulations for Food and Drug Administration (FDA) approval and clinical treatment. In this review, we focus on the oral peptide delivery, mainly summarizing the progress of recent strategies used to overcome oral barriers and the commercialization applications of related patents, which could facilitate the research and development (R & D) of clinical applications of oral delivery techniques for peptide drugs.

This manuscript aims to investigate the effects of resibufogenin on the proliferation, migration and invasion of human hepatocellular carcinoma cells and its related mechanisms. MTT assay was used to determine the inhibitory effect of resibufogenin on the growth of four hepatocellular carcinoma cells in vitro. Wound-healing assay and Transwell assay were used to evaluate the migration and invasion ability of resibufogenin on MHCC-97H cells. Western blot assay was used to detect the expression of migration and invasion related proteins in MHCC-97H cells treated with different concentrations of resibufogenin. The results showed that resibufogenin significantly inhibited the proliferation of hepatocellular carcinoma cells in vitro. The half maximal inhibitory concentration (IC₅₀) values on MHCC-97H, HepG2, SK-Hep-1 and Huh-7 cells were 0.55 ± 0.06, 2.83 ± 0.24, 5.25 ± 0.49, 14.89 ± 2.28 μmol·L^-1, respectively. Resibufogenin also suppressed the migration and invasion of MHCC-97H cells in a concentration-dependent manner. The protein expression of integrin α2, integrin α6, integrin β1, N-cadherin, matrix metalloproteinase 2 (MMP2) and transcription factor Twist in MHCC-97H cells were decreased significantly with the increase of the concentration of resibufogenin, while the protein expression of E-cadherin increased. In addition, we found that p-PI3K/PI3K and p-AKT/AKT ratios were significantly reduced after treatment with resibufogenin. In conclusion, resibufogenin can inhibit the proliferation, migration and invasion of hepatocellular carcinoma MHCC-97H cells in vitro, which is related to the regulation of intracellular migration and invasion protein expression and PI3K/AKT signaling pathway.

This study evaluated the regulatory effect of curcumin on memory follicular T cells (mTf) in obese mice with ulcerative colitis on the basis of determining its effective treatment of ulcerative colitis in obese mice. Forty male leptin mutant (ob/ob) mice were randomly divided into control group, control + curcumin group, dextran sodium sulfate (DSS) group and DSS + curcumin group, with 10 mice in each group. Mice in the DSS group and the DSS + curcumin group were induced by DSS to establish chronic ulcerative colitis model, and mice in the control + curcumin group and the DSS + curcumin group were given curcumin (200 mg·kg^-1·d^-1) by intragastric administration. Mice were sacrificed under anesthesia, and colon mass index, colon length and other conditions were observed in each group. Pathological injury of colonic was performed after HE staining. The levels of memory follicular helper T cells (mTfh) and memory follicular regulatory T cells (mTfr) in spleen of mice were detected by flow cytometry. The expression levels of interleukin-10 (IL-10) and interleukin-17A (IL-17A) in colon tissue were detected by ELISA. The results showed that curcumin significantly increased the body weight and colon length of obese mice with colitis, and decreased the colon weight, colon mass index and pathological score (P < 0.05). Curcumin significantly reduced the levels of central memory follicular T cells (cmTf), mTfh1, mTfh17 cells and the content of pro-inflammatory cytokine IL-17A (P < 0.01). The levels of effector memory follicular T cells (emTf) and mTfr and the content of anti-inflammatory cytokine IL-10 were increased (P < 0.05, P < 0.01). Therefore, curcumin may treat colitis in obese mice by regulating the balance of mTf cell subsets.

Based on the research system of computer-aided drug design combined with complex network analysis, the potential mechanism of Dunhuang Dabupi Decoction in preventing and treating gastric cancer (GC) is analyzed, and the scientific connotation of its prescription rules is explored through the efficacy grouping. To study the effect of Dabupi Decoction freeze-dried powder solution on the proliferation activity of gastric cancer cells through cell experiments; the TCMSP and TCMID databases were used to collect the compound components of Dabupi Decoction. Swiss Target Prediction is used to predict potential targets of compounds. DrugBank, GeneCards, TTD, and DisGeNET were used to collect potential targets for gastric cancer. Analyze protein interactions of potential targets through the STRING database. DAVID database was used for KEGG enrichment analysis; Dabupi Decoction was divided into Wenzhong group (dried ginger), Yiqi group (ginseng, licorice, Atractylodes macrocephala), nourishing Yin group (Ophiopogon japonicus, Schisandra) and Jiangni group according to its efficacy characteristics. The inverse group (inula) has 4 functional compatibility groups. Cytoscape was used to construct a network of "medicinal flavor-potential active ingredient-key target" respectively, and the network was used to analyze the scientific connotation of the compatibility of efficacy groups. The Schrödinger software was used to verify the molecular docking of the core components and the core targets. The material basis of the Dabupi Decoction to prevent and treat gastric cancer was discovered through the combination of pattern analysis and combined free energy calculation. The core drug was analyzed from the perspective of dynamics through molecular dynamics simulation. Potential targets and representative potential compounds interact with each other. Cell experiments confirmed that Dabupitang freeze-dried powder solution can down-regulate the mitochondrial membrane potential of AGS gastric cancer cells, block the cell cycle in the G₀/G₁ phase (P < 0.05), and inhibit its proliferation (P < 0.05). The pathways enriched by the four functional groups contained in Dabupi Decoction are mainly distributed in the body's energy metabolism, inflammation-immune system regulation, and cycle-apoptotic functions. Each module is connected by a common target gene and has its own focus. The results of molecular docking showed that the compounds liquiritigenin, quercetin, kaempferol, isorhamnetin, methylophiopogonanone A, etc. may be the effective multi-target components of Dabupi Decoction. Estrogen receptor 1, androgen receptor, ATP-binding cassette superfamily G member 2, epidermal growth factor receptor, glycogen synthase kinase-3 beta and other targets have good affinity with each potential active compound, which may be a potential target of Dabupi Decoction for preventing and treating gastric cancer. Among them, kaempferol and the drug target EGFR not only have good binding ability, but also have good binding stability. This study is based on computer-aided drug design combined with complex network analysis strategies to initially reveal the material basis and molecular mechanism of Dabupi Decoction in the prevention and treatment of gastric cancer. It also explores the scientific connotation of Dabupi Decoction in the prevention and treatment of gastric cancer with different efficacy groups, and its clinical application provide chemical bioinformatics basis.

The remodeling of phospholipid includes two processes: deacylation and reacylation. It realizes the conversion of nascent phospholipids to mature phospholipids by changing the length and types of fatty acids at specific sites of phospholipids, which is a key step in phospholipid metabolism. Phospholipids are not only the basic components of biological membranes, but also participate in the transduction of many molecular signals in cells. Therefore, phospholipid remodeling disorders can affect the structure and function of cell membranes, as well as the activity of membrane proteins, causing a series of intricate signaling cascades, and finally lead to many pathological changes including neurodegeneration. This paper reviews the basic process of phospholipid remodeling and the involvement of its key enzymes, calcium independent group VIA phospholipase A₂ (iPLA₂β), peroxiredoxin 6 (PRDX6), calcium independent group VIB phospholipase A₂ (iPLA₂γ) as well as acyl-CoA lysocardiolipin acyltransferase 1 (ALCAT1) in the pathology of Parkinson's disease. The mutations in the gene encoding iPLA₂β, PLA2G6, have been widely reported to be directly related to hereditary Parkinson disease-14 (PARK14). Here we focus on the molecular mechanism of iPLA₂β in the development of Parkinson's disease, mainly involving phospholipid fatty acid metabolism disorders, mitochondrial physiology abnormalities and α-synuclein aggregate formation and other aspects, which will help to understand the role of phospholipid remodeling in Parkinson's disease, and provide new clues for the development of new Parkinson's disease diagnosis and treatment strategies.