Bacterial biofilm widely exists in all kinds of bacteria, and is related to about 80 percent of bacterial infections. It is one of the main reasons for bacterial tolerance and resistance to existing antibiotics. Therefore, there is unmet clinical need for new anti-biofilm drugs. At present, there are three kinds of anti-biofilm agents under research, including biofilm inhibitors, biofilm dispersal agents and biofilm eradication agents. Among them, the biofilm eradication agent is unique, which can not only kill bacteria in biofilm but also eliminate biofilm as a monotherapy. Based on modifications of natural products with antibacterial activity, a variety of compounds with biofilm eradicating activities have been obtained, such as, acyldepsipeptides, pyrrolomycins, halogenated phenazines and halogenated 8-hydroxyquinolines. In this review, we summarize several major biofilm eradication agents above according to their structures and mechanisms.

This study investigated the protective effect of chrysin on hepatic fibrosis by regulating AMP-activated kinase (AMPK)-NOD-like receptor protein 3 (NLRP3) mediated pyroptosis pathway. The hepatic fibrosis model of mice was established by thioacetamide (TAA) in vivo. Except the control and chrysin alone groups, the mice were injected intraperitoneally with TAA at 100 mg·kg^-1, three times per week for the first week. From the 2^nd to 5^th week, mice were injected intraperitoneally with TAA at 200 mg·kg^-1, three times per week for the next 4 weeks. Chrysin groups were intragastrically administrated once per day to 5^th week. The histopathological changes were detected by HE and Masson staining. The levels of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were assessed by the kits. All animal experiments were approved by the Medical Ethics Committee of Affiliated Zhongshan Hospital of Dalian University (DWLL2019060). LX-2 cells were stimulated by (transforming growth factor-β, TGF-β) in vitro. The protein expressions of AMPKα, p-AMPKα, NLRP3, cysteinyl aspartate specific proteinase-1 (caspase-1), gasdermin D (GSDMD) were detected by Western blot, and the mRNA levels of collagen-Ι, α-smooth muscle actin (α-SMA), interleukin-1β (IL-1β), IL-18, caspase-1, GSDMD were analysis by reverse transcription-polymerase chain reaction (RT-PCR). Chrysin attenuated the increases in serum AST and ALT levels in the TAA group, while significantly improved the changes of liver morphology, reduced liver tissue inflammatory cell infiltration and inhibited collagens deposition. Compared with TAA group, chrysin effectively activated AMPKα phosphorylation and inhibited hepatic NLRP3 inflammasome activation. Additionally, the protein expressions and mRNA levels of IL-1β, IL-18, caspase-1 and GSDMD in chrysin groups were decreased. Chrysin inhibited the expressions of collagen-Ι and α-SMA, enhanced the phosphorylation of AMPKα, and decreased the expressions of NLRP3 and GSDMD. Therefore, chrysin may inhibit inflammatory injury and pyroptosis possibly by activating AMPK and inhibiting NLRP3 inflammasome to alleviate hepatic fibrosis.

Attenuated Salmonella typhimurium VNP20009 is a widely used natural oncolytic bacterium, which has great application potential given its unique characteristics, including clinical safety, tumor targeting specificity, and explicit genome sequence. Here, we show that tumor progression can be effectively reduced by intraperitoneal administration with VNP20009 in a mouse model of melanoma (all animal experiments were conducted in accordance with the Animal Ethics Committee of China Pharmaceutical University); co-culture experiment in vitro demonstrated that VNP20009 can induce the polarization of macrophage M1, accompanied by expression of inflammation-related factors; flow cytometry analysis showed that VNP20009 induced the increase of immune cell infiltration in tumor. Further analysis showed that T cells infiltration in tumor-draining lymph node (TDLN) increased, and VNP20009 induced the activation of CD4⁺ T cells and CD8⁺ T cells in tumor. Our results demonstrate that VNP20009 treatment significantly inhibited melanoma tumors by remodeling tumor-associated macrophages to an M1-like phenotype, as well as recruiting and activating cytotoxic T cells, combined with its own antigenic activity to exert anti-tumor immunity.

As an important component of nucleosomes on the chromatin of eukaryotic cells, histones play an important role in the development and progression of tumour diseases by regulating epigenetic post-translational modifications such as acetylation and methylation. In addition, development of inhibitors targeting methyltransferase and deacetylase provides novel therapeutic strategies for cancer treatment. Mass spectrometry-based proteomics can reveal the global changes of histone modifications under the action of drugs during disease progression, which in turn provides important support for revealing drug action mechanism, drug resistance mechanism, and investigating novel drug combination strategies. This article focuses on the progress and status of proteomic research on a variety of histone modifying enzyme inhibitors, including methyltransferase inhibitors and histone deacetylase inhibitors, which will help to understand the current and further utilization of proteomics in studying histone modifications.

Asparaginyl endopeptidases (AEPs) in plants belong to the family of cysteine protease that undergo self-activation in the form of zymogen in acidic vacuole and play important physiological roles in maturation of seed storage proteins, protein degradation, programmed cell death and host defense. Bioprocessing enzymes (peptidyl Asx-specific ligases, PALs) that promote the maturation of cyclotides have recently been isolated and identified from several cyclotide-rich plants. PALs derived from AEPs can site-specifically catalyze the formation of asparagine or aspartate peptide bonds. Due to the advantages of relatively traceless peptide bonds and broad substrate spectrum and high catalytic efficiency, they have been playing important roles in the cyclization and modification of peptides and proteins, and are powerful tools for improving the stability of peptide drugs. This review describes the physiological functions of AEPs in plants and summarizes the discoveries, structural characteristics, catalytic mechanism and protein engineering of PALs, as well as the limitation of their applications and future trends. In addition, the applications of PALs in cyclotides biosynthesis and the development of macrocyclic peptides are highlighted, with the aim of providing a new idea for the biocatalytic synthesis of cyclic peptides.

The quality control of Chinese patent medicines containing animal-derived crude drugs is relatively difficult, because the effective constituents of most animal-derived crude drugs remain unknown. Even if there are relevant methods, they are usually qualitative, and quantitative indicators are either lacking or have poor specificity. This paper has proposed to use molecular quantitative technology to control the quality of Chinese patent medicines containing animal-derived crude drugs. In this study, a molecular quantitative method based on fluorescence quantitative PCR was established for the determination of Jinqian Baihua She in Jinlong Capsule. The method has good specificity, sensitivity, and repeatability. There is a good linear relationship between the content of DNA fragments and the CT (cycle threshold) value. The content of the Bungarus multicinctus-specific fragment in Jinlong Capsule is 24.1-46.6 IU·mg^-1. It is suggested that the content of the specific fragment of Jinqian Baihua She should not be less than 19.3 IU·mg^-1 as one of the quality control criteria of Jinlong Capsule. The study can provide a reference for the quality control of Chinese patent medicines containing animal-derived crude drugs.

Total flavonoids of Dracocephalum moldavica L. (TFDM) is an effective component extracted and isolated from the traditional Uighur medicinal herb Cymbidium fragrans. Cymbidium fragrans has the effects of tonifying the heart and brain, promoting blood circulation and resolving blood stasis, and has been widely used in the treatment of cardiovascular and cerebrovascular diseases for a long time. The purpose of this study was to determine the effect of total flavonoids from Cymbidium fragrans on hypoxia/re-oxygenation (H/R) injury in H9c2 (rat cardiomyocytes) cells and its mechanism. A model (H/R) of hypoxia/re-oxygenation injury in H9c2 cells was established using hypoxia and glucose deprivation for 9 h combined with re-oxygenation and rehydration for 2 h to simulate myocardial ischemia-reperfusion injury. The effects of total flavonoids from Cymbidium fragrans on cell viability, markers of myocardial cell damage, oxidative stress levels, and reactive oxygen radical (ROS) content were investigated, Western blot was used to detect the expression of vascular endothelial growth factor B (VEGF-B) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway related proteins. The results showed that the total flavonoids of Cymbidium fragrans significantly increased the viability of myocardial cells after H/R injury, and decreased the content of lactate dehydrogenase (LDH) and creatine kinase isozyme (CK-MB) in the cell supernatant. It significantly reduced malondialdehyde (MDA), increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, and decreased intracellular ROS and nitric oxide (NO) content. Western blot analysis showed that the total flavonoids of Cymbidium fragrans decreased Bax levels in H9c2 cells damaged by H/R and increased Bcl-2 expression. Total flavones of Cymbidium fragrans upregulate VEGF-B/AMPK pathway related proteins VEGF-B, vascular endothelial growth factor receptor 1 (VEGFR-1), neuropilin 1 (NRP-1), peroxisome-proliferator-activated receptor γ coactivator-1α (PGC-1α), phosphorylated adenosine monophosphate activated protein (p-AMPK) and phospho mechanistic target of rapamycin (p-MTOR) levels. The above research results indicate that the total flavonoids of Cymbidium can significantly reduce the H/R injury of myocardial cells, which may be related to the upregulation of VEGF-B/AMPK pathway and inhibition of oxidative stress response.

Single cell RNA sequencing (scRNA-seq) is an advanced technology to study the transcriptome information at the single cell level. The application of this technology can attribute to analyze the heterogeneous map of cells in the process of disease development, and precisely identify the specific cell subsets that are responsive to pharmacological therapy. Currently, scRNA-seq technology has been widely applied in the field of drug research, including studies on therapeutic targets, drug-induced adverse reactions, drug resistance and vaccine. This work reviews the application of scRNA-seq technology in drug discovery, which offers a scientific basis for personalized and accurate medication therapy.

Squalene epoxidase (SQLE) is a potential target for the treatment of liver cancer. Bioinformatics analysis indicated that the high expression of SQLE was closely related to the clinical stage and poor prognosis of patients with liver cancer. However, the existing inhibitors against SQLE 195 tyrosine residue (Y195) cannot be used clinically due to severe side effects. In this study, 35 small-molecule compounds targeting SQLE 335 tyrosine residue (Y335) were selected by computer virtual screening. Combined with MTT assay, 3 candidate compounds (19^#, 31^# and 35^#) with significant inhibitory effects on the proliferation of Huh7 cell line were obtained. Further studies showed that these 3 compounds could inhibit the migration of Huh7 cells, reduce the contents of total and free cholesterol, up-regulate the expression of tumor suppressor gene PTEN, and down-regulate the expression of PI3K and AKT proteins. The results showed that the novel inhibitors 19^#, 31^# and 35^# targeting SQLE Y335 could reduce cholesterol content, inhibit the proliferation and migration of Huh7, thus playing an anti-liver cancer role.

Four new triterpenoids, together with six known analogues, were isolated from an aqueous extract of the Ziziphus jujuba var. spinosa seeds, by multiple column chromatographic separation methods using stationary phases of macroporous adsorption resin, MCI resin, normal phase silica gel, Sephadex LH-20, and Toyopearl HW-40C as well as preparative thin-layer chromatography and reversed-phase HPLC. Their structures were determined by spectroscopic data analysis, the new structures were trivially named jujubaceanothoside A (1), 23-epijujuboside A (2), and jujubosides J and K (3 and 4), while the known analogues were identified as jujubosides A-C (5-7) and II (8), alphitolic acid (9), and betulinic acid (10). The structure of 1 was confirmed by single crystal X-ray diffraction.