Using a H₂O₂-induced BRL cell senescence model, we investigated the anti-aging effects of drug-containing serums of Erzhi Wan (EZW) and various polar extracts (petroleum ether, ethyl acetate, n-butanol, water, and iridoid glycoside-enriched fractions). Cell viability was detected by MTT assay. Cell senescence was evaluated with β-galactosidase staining assay. Intracellular reactive oxygen species (ROS) were measured by flow cytometry. UFLC-Q-TOF-MS/MS was used to identify chemical components in EZW and the extracts, and molecular docking technology was used to predict the anti-aging components of EZW. Results showed that treatment of cells with 600 μmol·L^-1 H₂O₂ for 72 h markedly induced cell senescence, inhibited cell proliferation and increased intracellular β-galactosidase activity and ROS levels. If cells were pretreated with drug-containing serum of EZW this induction of senescence was decreased. A total of 49 chemical compounds were identified in EZW by liquid chromatography-mass spectrometry, 14 of these were identified by molecular docking as potential active ingredients. Based on these analyses, and the in vitro experiments with polar extracts, we conclude that the anti-aging components of EZW are triterpenes, flavonoids and phenyl alcohols, providing a basis for further elucidation of the active agents and mechanism of the anti-aging effect of EZW.

Bioorthogonal fluorogenic probes are becoming an ideal tool for live-cell fluorescence imaging. With the tetrazine bioorthogonal fluorogenic probe that displays fluorescence enhancement, the tetrazine plays the dual-role of a bioorthogonal reaction unit and the fluorescence quenching unit. The "off" and "on" states of the fluorescence probe are mainly controlled through inverse electron demand Diels-Alder (IEDDA) bioorthogonal reaction. We designed a series of turn-on tetrazine fluorescent probes with Donor-π-Acceptor (D-π-A) structure to achieve a high signal-to-noise ratio and specificity of fluorescence imaging. This series of probes reacted with the dienophile bicyclononyne, and then generated pyridazine structure in-situ that acted as an electron acceptor, resulting in a new D-π-A effect of fluorescent dyes, turning on the intramolecular charge transfer (ICT) effect. By adjusting the electron-donating groups and the degree of conjugation, tunable fluorescence spectra between 400-647 nm with fluorescence turn-on enhanced up to 500-fold have been achieved. This research lays the foundation for the further optimization of tetrazine bioorthogonal fluorescent probes and their applications in molecular imaging and biomedical fields.

The structure and diversity of the intestinal flora in rats exposed to high altitude hypoxia was investigated. Animal experiments strictly follow the regulations of Medical Laboratory Animal Ethics Committee of Qinghai University, School of Medicine. SD rats were randomly divided into a control group, a moderate altitude hypoxia group, and a high altitude hypoxia group. The pH value of the feces was measured and histopathological changes in the small intestine were determined by HE staining, and the intestinal flora were characterized by 16S rDNA high throughput sequencing technology on the 3rd, 7th, 15th, and 30th day of hypoxia exposure. Compared with the control group, the fecal pH value of rats in the moderate altitude hypoxia group and the high altitude hypoxia group was decreased significantly. The lamina propria and submucosa capillaries were slightly dilated and congested on the 3rd day in the moderate altitude hypoxia group. In the high altitude hypoxia group the submembrane capillaries were dilated and congested, the lamina propria of the mucosa showed mild edema, and the lymphatic vessels were dilated on the 7th day. The composition and diversity of intestinal flora in these rats changed significantly with prolonged exposure to the high altitude hypoxic environment. A total of 35 phyla, 87 classes, 205 orders, 337 families, 638 genera, and 256 species were annotated in the three groups of rats, including Firmicutes, Clostridia, Clostridiales, Ruminococcaceae, Akkermansia, and Lactobacillus_murinus. Compared with the control group, the intestinal flora of the hypoxic groups showed the most significant changes by the 15th day. There were 9 microbiota of gut microorganisms with relative abundance in the moderate altitude hypoxia group, of which Rikenellaceae_RC9_gut_group bacteria was the most common, there were 19 different microbiota of gut microorganisms with higher relative abundance in the high altitude hypoxia group, of which Ruminococcaceae bacteria was the most common. The results of this study indicate significant changes in the intestinal flora with high altitude hypoxia, and establish a foundation for further research on the initiation and development of diseases and drug metabolism in high altitude hypoxia.

Qualitative and quantitative methods were used to establish the quality of different medicinal parts of Poria cocos (Poriae Cutis, rubra Poria, white Poria, Poria cum Radix Pini) by using ultra-performance convergence chromatography coupled with photo-diode array and quadrupole time-of-flight mass spectrometry (UPC²-PDA-Q-TOF/MS^E). A total of 18 chromatographic peaks were detected from Poria cocos by UPC²-PDA. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to compare the four medicinal parts. The results showed that there were significant differences in the components of different medicinal parts, and the main triterpenoic acids were poricoic acid A, poricoic acid B, dehydroeburicoic acid, and dehydrotrametenolic acid. When combined with the common active component polyporenic acid C, a method for determination of five triterpenoic acids in different parts of Poria cocos was established. These components could be separated within 15 min, and the amount of methanol was 3.63% of that of HPLC method. Taking the five triterpenoid acids as an index, the content of triterpenoid acids in different parts of Poria cocos from high to low were Poriae Cutis, rubra Poria, white Poria and Poria cum Radix Pini. The method is simple, rapid, and uses minimal solvent. The mobile phase of environment-friendly gas carbon dioxide has unique advantages in reducing environmental pollution, which can provide a basis for the development and standard formulation of Poria cocos and its related products.

To investigate the influence factors and effects of metal or dissolving microneedles on the formation and healing of skin microchannels, the pencil-shaped or conical stainless steel microneedles with different lengths, tip to tip space and base area, and the pencil-shaped dissolving microneedles with different tip to tip space were used. The microneedles were applied to the skin of epilatory mice and rats, and the effects of various microneedle parameters, application parameters, and animals on the microchannels were explored by the transepidermal water loss (TEWL) and methylene blue staining. Visually observe the skin local irritation caused by the microneedles. The animal experiments were approved by the Animal Experiments Welfare and Ethical Committee of Zhejiang University of Technology. The application time of the microneedle should be maintained at 30 s or more. When the insertion forces were 2, 4, 8 N, and the TEWL initial values of the formed microchannels were 12.9, 33.0, 40.4 g·m^-2·h^-1, respectively. When the length of metal microneedle were 400, 600, 800 μm, and the TEWL initial values of the formed microchannels were 37.1, 40.4, 49.5 g·m^-2·h^-1, respectively. When the tip to tip space of metal microneedle were 400, 600, 800 μm, and the TEWL initial values of the formed microchannels were 33.2, 40.4, 55.8 g·m^-2·h^-1, respectively. When the base area of metal microneedle were 0.16, 0.35, 0.62 cm², and the TEWL initial values of the formed microchannels were 35.1, 40.4, 67.1 g·m^-2·h^-1, respectively. The effects of conical and pencil-shaped microneedles are similar. When the tip to tip space of pencil shaped dissolving microneedle were 400, 600, 800 μm, and the TEWL initial values of the formed microchannels were 49.8, 60.5, 70.5 g·m^-2·h^-1, respectively. The TEWL baseline values of animal skins of different genders and series are different, but the tendency of microchannels formation and closure is similar. Visual inspection revealed that the slight erythema caused by the microneedles subsided within 24 h. Microneedles of different parameters have different effects on microchannels. The microchannels closed within 24 or 48 h, and the skin local irritation caused by microneedle was mild.

In the past few decades, our understanding of platelets has made great progress. Platelets play an unexpected central role in cancer and greatly affect the behavior of cancer cells. At the same time, the physiology and phenotype of platelets are also affected by cancer cells. Therefore, platelet-based tumor targeted therapy strategies have attracted the attention of researchers, but the limitations of their application require more attention. In this paper, the strategies of platelet-based tumor targeted therapy are summarized, and the strategies of platelet mimicking nanocarrier delivery, platelet hitch riding, platelet membrane coating biomimetic and engineered platelet targeting are mainly introduced. The easy activation, hard storage and unknown functional and phenotypic changes of platelets were discussed. At the same time, the strategy of platelet-based targeted tumor therapy is reviewed from theoretical basis and practical application. The development potential of platelets in the field of tumor diagnosis and treatment is discussed, which will provide some theoretical reference for the study of platelet-related tumor diagnosis and targeted therapy.

Malignant tumors seriously endanger human life and health, and their treatment has always been a research focus of scientists all over the world. Natural flavonoids and their derivatives have a variety of biological activities, especially regarding antitumor growth, with unique biological activities. They can interfere with the growth cycle of tumor cells, change the mitochondrial membrane potential, promote apoptosis, and can reduce the immune escape of tumor cells and prevent tumor metastasis by improving human immunity. In the human body, they regulate the biological signal transduction, leading to the up-regulation of pro-apoptotic protein expression. They inhibit the growth of solid tumors by regulating the growth of vascular epithelial cells and blocking the formation of blood vessels in tumor tissue. Recent studies have shown that these compounds can play an important role in the treatment of various human tumors and are expected to be developed into new antitumor drugs. This review summarizes the recent research results on the antitumor mechanism of flavonoids and their ability to inhibit tumor growth.

Macrophages are highly plastic and heterogeneous. In different types of inflammatory diseases, or at different stages of the same disease, macrophages can undergo phenotypic transformation to elicit different functions. Hence, exploring new regulatory mechanism of macrophage polarization and seeking for new key mediators will lay the foundation for the diagnosis and treatment of macrophage-related diseases, such as inflammatory diseases, autoimmune diseases, and cancer. Interferon regulatory factors (IRFs) have been reported to play an important role in the maturation and differentiation of macrophages. In this review, we will describe the structure and modulation pattern of IRFs, and then further summarize the molecular mechanism and signal regulation network of IRFs in pathological processes of related diseases through controlling macrophage polarization. Our review will explore the new therapeutic strategy and potential drug targets for related diseases.

Abnormal aggregation of amyloid-β protein (Aβ) in brain plays a vital role in the occurrence of Alzheimer's disease (AD). Hence, inhibiting Aβ aggregation is one major tactic for therapy of AD. Previous studies have found that tolcapone can inhibit Aβ42 aggregation and reduce the cytotoxicity induced by Aβ42 aggregates, but clinical studies have found that tolcapone has strong liver toxicity. To reduce the liver toxicity of tolcapone, its side chain structure was modified to obtain its derivative phenethyl (E)-2-cyano-3-(3, 4 dihydroxy-5-nitrobenzene)-acrylate (PCDNA). Thioflavin T (ThT) and atomic force microscopy (AFM) assays were used to explore the inhibitory effect of PCDNA on Aβ42 fibrillogenesis. The cytotoxicity assays were used to explore the inhibitory effect of PCDNA against the cytotoxicity induced by Aβ42 aggregates. In addition, the depolymerization effect of PCDNA on mature Aβ42 fibrils was also explored. Finally, molecular docking was used to explore the interaction between PCDNA and Aβ42 pentamer. These results lay the foundation for the study of the structural analogues of tolcapone as Aβ inhibitors.

Depression is one of the diseases with the highest disability rate in the world. A large number of studies have shown that the intake of unsaturated fatty acids can deal with depression while chronic overconsumption of saturated fatty acids is a risk factor for depression. It was suggested that the mechanism of saturated fatty acids inducing depression is related to the following four aspects: regulating the function which links to depression in whole brain and specific brain regions, including the hippocampus, the hypothalamic-pituitary-adrenal axis, the striatum, and the prefrontal cortex; stimulating the secretion of inflammatory factors; affecting the balance and function of metabolic regulatory hormones, including leptin, adiponectin, glucocorticoid, and insulin; inducing the disturbance of intestinal flora. This article reviews the relationship between dietary fatty acids and depression, and the possible mechanisms by which saturated fatty acids induce depression from the four aspects mentioned above.