Torpor refers to a state in which the metabolic activity in the body of the living animal is greatly reduced during the period of reduced food supply, which is manifested as a substantial decrease in body temperature, metabolic level, and exercise level. Mammals have a strict body temperature regulation system to maintain a constant body temperature. When the energy supply is insufficient for a long time, some mammals will enter a hibernation state. Torpor is very similar to the hibernation state. The research on the mechanism of torpor state is of great significance in aerospace, military medicine and other fields. This review summarizes the specific mechanisms regulating the occurrence of torpor from four aspects: adenylate cyclase activating polypeptide (adcyap) neurons, leptin, pyroglutamylated RFamide peptide (QRFP) neurons, and sympathetic nervous system, aiming to provide ideas for further research on the mechanism of torpor.

Idiosyncratic drug-induced liver injury (IDILI) is an unpredictable serious adverse drug reaction, which only occurs in a minority of special susceptible individuals. Although the mechanism of IDILI has not been fully understood, several hypotheses have been proposed to explain the action mode and specific mechanism of IDILI. Of these hypotheses, inflammatory stress hypothesis is one of the most important theories. Under the condition of inflammatory stress, drugs interact with inflammation and mediate the occurrence of IDILI through a variety of mechanisms, which can induce the production of inflammatory cytokines, activate coagulation system, affect the activity of metabolites, induce cholestasis, affect mitochondrial damage, and others. This review will summarize the main mechanisms and influencing factors of IDILI mediated by inflammatory stress, in order to provide a reference for preclinical drug development and basic research on drug-induced liver injury.

Hyperuricemia is not only the biochemical basis of gout, but also closely related to the development of metabolic syndrome, cardiovascular diseases, chronic kidney disease, etc. Xanthine oxidase (XOD) is the key catalytic enzyme for uric acid biosynthesis, therefore the vital target for anti-hyperuricemic drugs. In this study, compound CC18022 was designed and synthesized specifically targeting to XOD. Molecular docking analysis indicated a fairly tight binding between CC18022 and XOD. In the in vitro study, CC18022 significantly inhibited XOD activity with a half maximal inhibitory concentration (IC₅₀) value in the order of nmol·L^-1, which is relative to the XOD inhibitor febuxostat. By using both acute and chronic hyperuricemic mice model, compound CC18022 was found to have serum uric acid-lowering effect in a dose-dependent manner in vivo. The animal welfare and experimental processes were in accordance with the provisions of the Animal Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences. In the acute hyperuricemic mice, CC18022 significantly inhibited serum XOD activity, and also the XOD activity in intestine and liver, which were related to purine absorption and metabolism. Therefore, the novel compound CC18022 exhibited significant inhibition on XOD activity and anti-hyperuricemic effects, making it a favorable candidate for further research.

This study was designed to explore the protective effect and underlying mechanism of catalpol on hepatocyte apoptosis in nonalcoholic fatty liver disease (NAFLD). High fat diet (HFD) was used to establish NAFLD model in the in vivo experiment, and the procedures of the experiments and animal care protocol were approved by the Animal Care and Use Committee of Jianghan University. Human liver cancer cell line HepG2 was treated with palmitate (PA) to establish a lipid toxicity model in the in vitro experiments. The results showed that catalpol significantly decreased the contents of serum total glyceride (TG), total cholesterol (TC), alanine aminotransferase (ALT), and aspartate transaminase (AST) in HFD-fed mice. Results of TUNEL staining and flow cytometry analyses revealed that catalpol significantly inhibited hepatocytes apoptosis in HFD-fed mice and PA-treated HepG2 cells. Moreover, catalpol treatment significantly reduced the endoplasmic reticulum stress-related protein expression levels of binding immunoglobulin protein (BiP), phosphorylated PKR-like endoplasmic reticulum kinase (p-PERK), inositol-requiring kinase 1α (IRE1α), and transcriptional factor activating transcription factor 6 (ATF6), and apoptosis-related protein expression levels of C/EBP homology protein (CHOP), phosphorylated c-Jun N-terminal kinase (p-JNK), and cleaved cysteinyl aspartate specific proteinases (caspases)-12, -9, and -3 in HFD-fed mice and PA-treated HepG2 cells. Furthermore, endoplasmic reticulum stress agonist tunicamycin (TM) significantly reversed the inhibitory effect of catalpol on protein expression levels of BiP, p-PERK, IRE1α, and ATF6, subsequently the inhibitory effect of catalpol on expression levels of CHOP, p-JNK, Bcl-2, Bax, and cleaved caspases (-12, -9, and -3) was also attenuated in PA-treated HepG2 cells. Taken together, these findings demonstrated that catalpol could inhibit hepatocytes apoptosis and had a significant protective effect on liver injury, and its mechanism might be related to the relief of endoplasmic reticulum stress.

Strict regulation of human immunodeficiency virus type 1 (HIV-1) protease function is critical for efficient production of mature viral particles. During viral protein expression and viral assembly, HIV-1 protease (PR) located within Gag-Pol precursor must be inactive to prevent premature cytoplasmic processing of the viral Gag and Gag-Pol precursors. Premature activation of HIV-1 precursors leads to major defects in viral assembly and production of viral particles. Specifically activating the protease in the precursor protein can directly inhibit the replication of the virus. In addition, HIV-1 PR is able to induce cell apoptosis. In this study, we identified 6 small molecule compounds using a cell-based assay for screening compounds that activate HIV-1 PR and induce premature of HIV-1 precursors. Results showed the active compounds are able to activate HIV-1 PR, inhibit HIV-1 replication, and induce cell apoptosis. This study provides ideas for the research and development of antiviral drugs.

In this study, the regulatory effects of chlorogenic acid (CGA) on the expression of programmed cell death ligand 1 (PD-L1) in esophageal squamous cell carcinoma (ESCC), as well as the role of interferon γ (IFN-γ), has been discussed using both in vitro and in vivo animal models. ESCC murine model was established according to the standard operating procedures (SOP) of Animal Experiment Center of Institute of Materia Medica, Chinese Academy of Medical Sciences. The expression of PD-L1 in esophageal tissues of murine models was analyzed using the microarray assay. Then, the results were verified by qRT-PCR, Western blot and immunohistochemistry (IHC) staining, the molecular mechanism was explored in KYSE180 and KYSE510 ESCC cells in vitro. The results showed that CGA could suppress the expression of PD-L1 in tumor tissues in murine models significantly, rather than the expression in KYSE180 and KYSE510 ESCC cells in vitro. However, after the pretreatment of IFN-γ, the expression of PD-L1 was significantly increased, then it was down-regulated by CGA in both dose- and time-dependent manner. Meanwhile, the expression of interferon regulatory factor 1 (IRF1), an upstream regulatory factor of PD-L1, was suppressed by CGA in both KYSE180 and KYSE510 pretreated with IFN-γ, which was consistent with the expression of PD-L1. These results indicate that CGA down-regulates the expression of PD-L1 in ESCC via IFN-γ-IRF1 signaling pathway, providing the molecular theoretical basis for exploration of new treatment of ESCC.

Attenuated Salmonella VNP20009 specifically colonizes and proliferates within tumor tissues and inhibits tumor growth. It has been used as drug delivery vehicle or in combination with other therapies (such as chemotherapy), which shows a good application potential in tumor therapy. In this paper, study was conducted to determine the physiological changes of growth curve and formation of bacterial biofilm of VNP20009 under various environmental stresses, such as temperature, pH, and H₂O₂. The results showed that VNP20009 could grow normally under the conditions of 42 ℃, pH 6.5, and 1 mmol·L^-1 H₂O₂. Furthermore, the weak acid environment was beneficial to the biofilm formation of VNP20009. This study provides a basis for in-depth study of the survival mechanism and application of attenuated Salmonella.

Dammarane-type triterpenoid saponins are regarded as the main active constituents of Gynostemma longipes C.Y.Wu. By using MCI and silica gel column chromatography, as well as preparative HPLC, we isolated four new dammarane-type triterpenoid saponins from the polar saponin fraction of G. longipes C.Y.Wu. Their structures were determined by comprehensive analyses of NMR and MS data and identified as (20S)-3β, 20, 21-trihydroxydammar-19-oxo-24-ene-3-O-{[α-L-rhamnopyranosyl(1→2)]-[β-D-xylopyranosyl(1→3)]-α-L-arabinopyranosyl}-21-O-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside (1), (20S)-3β, 20, 21-trihydroxydammar-24-ene-19-oxo-3-O-[α-L-rhamnopyranosyl(1→2)]-[β-D-xylopyranosyl(1→3)]-α-L-arabinopyranosyl-21-O-α-L-rhamnopyranosyl(1→6)-β-D-glucopyranoside (2), (20S)-3β, 19, 20, 21-terahydroxydammar-24-ene-3-O-{[α-L-rhamnopyranosyl(1→2)]-[β-D-xylopyranosyl(1→3)]-α-L-arabinopyranosyl}-21-O-[β-D-glucopyranosyl(1→6)]-β-D-glucopyranoside (3), (20S)-3β, 20, 21-trihydroxydammar-24-ene-3-O-{[α-L-rhamnopyranosyl(1→2)]-[β-D-glucopyranosyl(1→3)]-β-D-glucopyranosyl}-21-O-[β-D-glucopyranosyl(1→6)]-β-D-glucopyranoside (4). Compounds 1-4 are new dammarane-type triterpenoid saponins which contain five glycosyl residues.

The compatibility of kanamycin with sodium citrate for the formulation of kanamycin sulfate injection was determined, including optimization of the amount of sodium citrate in the injection and the sterilization process. An HPLC coupled with an evaporative light scattering detector (ELSD) was used to measure the amount of sodium citrate and the impurity profiles. A validated post-column derivatization HPLC coupled with a fluorescence detector (FLD) was used to determine the correlation between specific impurities in a domestic factory and sodium citrate, and then the formulation was evaluated by HPLC coupled with mass detector (MS) characterization of degradation products. The results show that the amount of sodium citrate in kanamycin sulfate injection from a domestic factory is about 40 times higher than that of the Meiji formulation. Several specific impurities can be detected in solutions heated under simulated sterilization conditions (121 ℃), which were correlated with the amount of sodium citrate. Impurities were characterized by HPLC-MS/MS, and data showed that the identified impurities were interaction products of kanamycin and sodium citrate. These results indicate that greater attention should be directed at formula optimization in domestic factories, as it is crucial to the safety and efficacy of the preparations. Drug-excipient chemical compatibility should also be evaluated in the development of pharmaceutical dosages forms especially when the active pharmaceutical ingredients have a primary amine group.

In this study, in vitro experiments were conducted to investigate that sinomenine inhibits the macrophage classic activation by up-regulating the expression of paired immunoglobulin-like receptor B (PIR-B). A macrophage model with classic activation was established by lipopolysaccharide and interferon-gamma co-stimulation. Real-time fluorescence reverse transcription-polymerase chain reaction was executed for evaluating the PIR-B gene expression, and Western blot for PIR-B protein expression, in macrophages, respectively. The tumor necrosis factor α and interleukin 8 in cell culture supernatant were measured by enzyme-linked immunosorbent assay. The flow cytometry was utilized to detect M1 macrophages. The PIR-B expression in situ was observed by laser scanning confocal microscope. The results showed that sinomenine significantly increased the expression of PIR-B, markedly reduced the percentage of M1 macrophages, and decreased the levels of tumor necrosis factor α and interleukin 8 in the culture supernatant. The above results indicated that sinomenine can significantly inhibit the macrophage classic activation, and its mechanism may be related to the increase of PIR-B expression in macrophages. This pharmacological effect helps explain the pharmacodynamic mechanism of sinomenine in treating rheumatoid arthritis.