This study was designed to investigate the effect of dihydromyricetin (DHM) on inducing apoptosis of ovarian cancer cells A2780 through endoplasmic reticulum stress (ERS) pathway and the mechanisms involved in vitro and in vivo. A2780 cells were treated with different concentrations of DHM, and the protein expression levels of glucose-regulated protein 78 (GRP78) which is related to ERS increased, apoptotic proteins C/EBP-homologous protein (CHOP), and cysteinyl aspartate specific proteinase-12 (caspase-12) elevated. After pretreatment with ERS inhibitor, 4-phenyl butyric acid (4-PBA), following the intervention with DHM, the A2780 cell viability decreased and apoptotic rate increased. All animal welfare and experimental procedures were approved by the Animal Ethics Committee of Chongqing Medical University. Intraperitoneal injection of DHM suspension into nude mice with ovarian cancer could significantly inhibit the growth of transplanted tumor in vivo, increase the protein expression levels of GRP78, CHOP, and caspase-3. Moreover, swollen and broken endoplasmic reticulum could be observed in tumor tissues, suggesting that DHM intervention induces apoptosis mediated by ERS. The results indicated that DHM could induce apoptosis of ovarian cancer cells and inhibit the growth of transplanted tumors in nude mice, which might be related to the activation of ERS pathway.

To identify an effective structural modification strategy for improving the antitumor activity of fluoroquinolones, sixteen new 1-cyclopropyl-6-fluoro-7-(4-methyl-piperazin-1-yl)-3-arylidene-2, 3-dihydroquinolin-4(1H)-ones compounds (4a-4p), were designed and synthesized by a condensation reaction of dihydroquinolin-4-one (3) and aromatic aldehydes, based on the structure of ciprofloxacin (1). Their structures were characterized by elemental analysis and spectral data, and anti-cell proliferative activities against Hep-3B, Capan-1 and HL60 cell lines were measured by an MTT assay. Preliminary pharmacological results indicated that the synthesized target compounds had greater potency than ciprofloxacin (1). SAR revealed that the halophenyl compounds such as fluorophenyl (4h, 4i), chlorophenyl (4j, 4k) or bromophenyl compounds (4l, 4m) and aromatic heterocyclic compounds such as furanly (4n) or pyridyl compounds (4o, 4p) demonstrated better activity than the control compounds, and the IC₅₀ values of the chlorophenyl compounds 4j and 4k against Capan-1 cell growth were comparable to that of doxorubicin. Thus, a 3-arylidene as an isostere of the C-3 carboxylic acid group appears to be beneficial in improving the antitumor activity of fluoroquinolone. Furthermore, an α, β-unsaturated ketone fragment used as a potential bioisostere of C-3 carboxylic acid group may warrant further study.

Gut microbiota dysbiosis is closely related to a variety of host diseases. Recently, targeting the metabolic pathways of gut microbiota for the prevention and treatment of host diseases has become a frontier strategy and research hotspot. Inflammatory bowel disease (IBD) is a group of chronic progressive intestinal inflammatory diseases of unknown etiology. The relationship between IBD and gut microbiota disorders and bacterial respiratory/energy metabolism has been confirmed in recent research. This article will introduce the relationship among them, and propose a new treatment strategy to alleviate host gut inflammation by regulating gut microbiota respiration and energy metabolism based on the latest research progress. In the progression of IBD, the gut microbiota homeostasis is disturbed. The main reasons include two aspects:on the one hand, when the intestinal inflammation of the host occurs, with increasing of oxygen concentration in the intestinal cavity, facultative anaerobic bacteria, especially Enterobacteriaceae bacteria would proliferate abnormally; while the growth of absolute anaerobic bacteria such as Firmicutes is inhibited. On the other hand, intestinal inflammation by-products also support the expansion of facultative anaerobic bacteria, which ultimately exacerbates the imbalance of gut microbiota. Dysregulated intestinal flora will further disturb intestinal immune homeostasis and exacerbate intestinal inflammation. The latest research proposed the possibility that IBD can be alleviated by interfering with the respiration of bacteria, inhibiting the abnormal proliferation of bacteria, or increasing the level of "beneficial" metabolites of gut microbiota. The above studies suggest that alleviating host intestinal inflammation can be explored by focusing on the metabolic pathways of gut microbiota and regulating the intestinal bacterial respiration and energy metabolism, which is of great significance for the clinical treatment of IBD and the research of innovative drugs.

Glucose-6-phosphate dehydrogenase, a key enzyme in the pentose phosphate pathway, plays an important role in plant resistance. In this study, three full length cDNAs of G6PDH genes, namely AsG6PDH1, AsG6PDH2 and AsG6PDH3 were cloned from Aquilaria sinensis for the first time. The open reading frames (ORF) of AsG6PDH1, AsG6PDH2 and AsG6PDH3 were 1 809, 1 767 and 1 548 bp, respectively, encoding proteins of 602, 588 and 516 amino acid residues, respectively, with predicted molecular masses of 68.02, 67.02, 59.35 kDa, respectively. The three AsG6PDHs proteins shared high sequence identity with the G6PDH proteins of various plants, and possessed three conserved sequences found in G6PDH proteins. The phylogenic analysis showed that AsG6PDH1 and AsG6PDH2 were grouped in the plastidic cluster, while AsG6PDH3 was classified into the cytosolic cluster. Expression analysis indicated that AsG6PDH1 and AsG6PDH2 were primarily observed in root, while AsG6PDH3 was primarily observed in stem. The expression of AsG6PDH1, AsG6PDH2 and AsG6PDH3 was induced by salt, drought, low temperature and CdCl₂ treatments, while the content of AsG6PDH1 and AsG6PDH2 was most significantly increased by drought stress, and the transcript level of AsG6PDH3 was most significantly induced by metal stress. Furthermore, G6PDH activity was stimulated under salt, drought, low temperature and CdCl₂ treatments, and G6PDH activity was remarkably increased under drought stress. These results provide valuable insights into the role of AsG6PDHs in plant defense and the mechanism of agarwood formation.

The treatment plan for chronic pain often proceeds from a single drug to drug combination therapy. Sinomenine and ligustrazine, natural alkaline substances derived from traditional Chinese medicines, are expected to provide a new choice for combination analgesic therapy strategies. Here we establish a microdialysis sampling and HPLC-MS/MS quantification method for sinomenine, ligustrazine, gabapentin, paracetamol, pregabalin and amitriptyline in rat blood and brain extracellular fluid. Blood and brain microdialysis probes were implanted in the jugular vein toward the right atrium and left corpus striatum zone (AP +0.2 mm, ML 3.0 mm, DV 3.5 mm) in rats. The blood and brain microdialysis probes were perfused with citric acid buffer solution and Ringer's solution, respectively. Blood and brain extracellular fluid microdialysate were collected at intervals of 20 min at a perfusion rate of 1.5 μL·min^-1, and continuously collected for 24 h after administration. The liquid chromatographic separation used a C18-reversed phase chromatographic column (HSS T3 2.5 μm, 2.1 mm×50 mm), the mobile phase was methanol/water (containing 0.05‰ formic acid), and gradient elution was carried out at a flow rate of 0.3 mL·min^-1. Mass spectrometric detection used an electrospray ion source, positive ion mode and multi-reaction monitoring method. The selected quantitative ions for sinomenine, ligustrazine, gabapentin, paracetamol, pregabalin, amitriptyline and internal standard naloxone were 330/181, 137/80, 172/154, 152/110, 160/142, 278/233 and 328/310 respectively. The specificity, linear range, matrix effect, accuracy, precision, stability and probe recovery were investigated and confirmed to be suitable for the determination of the above drugs in rat blood and brain extracellular fluid microdialysate. The calculated in vivo recovery of microdialysis probes ranged from 19.38% to 25.88%. After intravenous administration of sinomenine (50 mg·kg^-1), ligustrazine (50 mg·kg^-1), gabapentin (50 mg·kg^-1), paracetamol (50 mg·kg^-1), pregabalin (50 mg·kg^-1) and amitriptyline (40 mg·kg^-1) to rats, the peak concentration in the blood microdialysate was in the range of 0.2-10 μg·mL^-1. Drug concentrations could also be detected in brain extracellular fluid microdialysate, however with lower levels (peak concentration:0.1-6 μg·mL^-1) than those of blood microdialysates at each time point. In conclusion, this method can be applied to microdialysis sampling and quantification of sinomenine, ligustrazine, gabapentin, paracetamol, pregabalin and amitriptyline in rats. The method will promote research in identifying herb-drug pharmacokinetic interactions, as well as safety concerns in combination-therapy strategies.

Cisplatin is one of the most commonly used chemotherapeutic drugs in clinic and has good therapeutic effect on various cancers, but the development of drug resistance limits its clinical treatment. The development of cisplatin resistance is caused by many factors, including the decrease of intracellular cisplatin accumulation, the inactivation of cisplatin by mercaptan proteins, the increase of DNA damage repair, apoptosis inhibition, tumor microenvironment and cancer stem cells. In recent years, traditional Chinese medicine (TCM) has been favored for its remarkable effect of reversing cisplatin resistance. This review will explore the mechanisms of cisplatin resistance and the combined modality treatment strategy of TCM to reverse cisplatin resistance, hoping to provide reference for clinical and scientific research.

In scientific research, it is often needed to knock in, knock out, knock down, or overexpress a specific gene in model organisms or specific types of cells to achieve precise regulation of experimental independent variables. In this case, various transgenic mice are required. The cyclization recombinase (Cre) can directly interact with different loxP (locus X over P1) DNA sequences without any cofactors to perform specific gene knock-in or knock-out at specific targets. Because of its advantages of simple action principles, high spatial specificity, and high reorganization efficiency, the Cre-loxP system is widely used in scientific research. Furthermore, the CreERT2 system (mutant of the fusion protein of Cre and estrogen receptor ligand binding domain) and the tetracycline (Tet)-on/off system, derived from the Cre-loxP system, have made the recombination of the target gene occur in temporal-specificity on the basis of spatial-specificity. This dual specificity of time and space is indispensable for research in specific directions such as fear memory and engram cells on the basis of reducing the impacts on experimental animals. Therefore, these derived systems have broad application prospects.

In recent years the role of sphingosine kinase 2 (SphK2), a key enzyme in the sphingolipid pathway, in the process of tumorigenesis has gradually been elucidated. Recent research has shown that SphK2 inhibitors can be used as anticancer drugs alone or in combination with existing drugs to increase the therapeutic sensitivity of drug-resistant tumors. Among them, one selective SphK2 inhibitor, ABC294640, shows excellent oral bioavailability and biodistribution in vivo and has now entered Phase Ⅱ clinical research. Therefore, developing innovative drugs based on SphK2 is of great interest. Herein, we discuss progress in understanding the role of SphK2 in tumorigenesis and review the recent development of inhibitors of SphK2.

In recent years therapeutic proteins products including therapeutic antibodies have become a major driving force for the modern biopharmaceutical industry. However, they have complex product quality attributes (PQAs) which limit product development and quality control (QC). Recent advances in high resolution mass spectrometry (MS) have led to the use of an MS-based multi-attribute method (MAM) for quality control testing of therapeutic proteins, which allows for direct measurement of multiple PQAs and identification of impurities. MAM helps to promote the improvement of product quality and QC and a reduction in manufacturing cost. To explore the application of MAM in QC, we discuss generic MAM workflow, the current state of MAM application in product development and QC, identify points to consider for use of MAM as a QC test, and summarize MAM's advantages and challenges in this article. The future application of MAM for therapeutic antibodies and the opportunities for its further development, use, and substitution for conventional methods is presented.

Oxygen is an essential element for life, which is mostly consumed at mitochondria for energy metabolism. For the genome inside nucleus, oxygen conducts structural regulations and chemical modifications through multiple pathways, where reactive oxygen species (ROS) serve as important messenger molecules. The highly activated ROS have the ability to produce different kinds of DNA lesions, while ferrous ions provide supports in many forms. Under the combinatorial action of oxygen and iron, almost all the genomic biochemical processes, such as replication, transcription and DNA damage repair are affected. Moreover, the variation of environmental oxygen concentration, particularly hypoxia that presents in many major diseases and critical physiological stages, provokes the responds at the genomic level. While the factors that lead to these genomic alterations are potential drug targets and deserve systematic investigations, herein, we collect the existing knowledge in the effects of ROS, ferrous ion and cell hypoxia on genome, along with brief discussions of the related drug molecules.