Malignant tumors are major diseases that endanger human health. Due to their complex and variable microenvironment, most anti-tumor drugs cannot precisely reach the focal tissue and be released in a controlled manner. Intelligent responsive nano carriers have become a hot spot in the field of anti-tumor drug delivery systems. As an excellent nano material, mesoporous silica has the advantages of non-toxic, stable, adjustable pore volume and pore diameter, and easy functional modification on the surface. By virtue of its perceptive response to the tumor microenvironment or physiological changes, it can achieve the targeted drug release or controlled drug release of the drug delivery system in the tissue, making it an ideal carrier for intelligent response drug delivery system. In this paper, we review the design strategies and current research status of smart responsive anti-tumor drug delivery systems based on mesoporous silica, in order to provide a reference for the development of anti-tumor drug nanoformulations.

The aim of this study was to investigate the effect of baicalein on a Drosophila model of hereditary Parkinson's disease caused by gene mutations and to preliminarily elucidate the mechanism of baicalein in delaying hereditary Parkinson's disease. In this paper, PTEN-induced putative kinase 1 (PINK1)-RNAi Parkinson's Drosophila were used as the model group and wild-type Drosophila w¹¹¹⁸ were used as the control group. Different doses of baicalein and Madopa were administered to the model group to observe their effects on the life span, motor ability, the abnormal rate of wings, dopamine content and dopaminergic neurons of PINK1-RNAi Parkinson's Drosophila and their effects on mitochondrial dysfunction including adenosine triphosphate (ATP), mitochondrial DNA (mtDNA) and reactive oxygen species (ROS) content. The results showed that the effective administration doses of baicalein were 0.8 mg·mL^-1 for low concentration, 1.6 mg·mL^-1 for medium concentration and 3.2 mg·mL^-1 for high concentration, and the optimal administration dose of the positive drug Madopa was 0.1 μg·mL^-1. Baicalein and Madopa could significantly improve the life span, exercise ability and reduce the abnormal rate of wings of PINK1-RNAi male Drosophila (P < 0.05), and low dose baicalein showed the best effect; baicalein could improve the loss of dopaminergic neurons, and the effects of low dose and high dose were the best, but Madopa showed no significant effect; baicalein and Madopa had no significant effect on dopamine content (P > 0.05). Baicalein and Madopa could increase the ATP content of PINK1-RNAi male Drosophila (P < 0.05), and low dose baicalein showed the best effect; middle dose baicalein could significantly increase the mtDNA content of PINK1-RNAi male Drosophila (P < 0.05), but Madopa had no significant effect; baicalein and Madopa had no significant effect on ROS content (P > 0.05).

Exosome is a self-secreted phospholipid bilayer nanovesicles, and has shown great potential in drug delivery field due to the important advantages of low immunogenicity and homologous targeting. Phototherapy, mainly includes photodynamic therapy (PDT) and photothermal therapy (PTT), utilize light to activate photoactive drug for tumor cell killing. The advanced therapeutic strategy shows low toxic side-effect and non-invasion precise advantages, and thus has made great progress in tumor treatment over the past few years. Therefore, using exosomes as a drug delivery system to deliver phototherapeutic agents can improve therapeutic performances with a reduced side-effect, and further enhance their application potential for clinical tumor therapy. This review focus on the rising cross-subjects field involving exosomes and phototherapy, and mainly introduce the research progress and relative case of exosomes-based delivery system for cancer phototherapy. Additionally, the advantages and challenges of exosome-based phototherapy are also discussed and proposed.

Drug-induced liver injury (DILI) is one of the common clinical adverse drug reactions and remains a major cause of drug restriction, development termination and withdrawal from the pharmaceutical market today. In recent years, a variety of chemical components and metabolites of traditional Chinese medicine (TCM), as well as the endogenous effector substances influenced by metabolism of both, have attracted much attention for their significant hepatoprotective activities. However, the mechanism of TCM against DILI is complex, the related effector substances are still unclear, and its metabolism-related studies are still relatively weak. Therefore, this review summarized the mechanisms of DILI and its treatment by TCM from the perspective of metabolism, and for the first time, innovatively classified the Chinese medicine effector substances into two categories: exogenous (active components and metabolites of TCM) and endogenous (intestinal probiotics and endogenous metabolites), in order to reduce the occurrence of DILI, explore and develop effective anti-drug-induced liver injury effector substances of TCM, and further develop clinical drugs with hepatoprotective effects.

Sphingosine kinase (SphK), sphingosine-1-phosphate (S1P) and S1P receptor (S1PR) are involved in the tumor biological processes such as tumor cell proliferation and migration, and play an important role in the development of cancer. In recent years, researchers have increasingly focused on the interaction between cancer cells and the tumor microenvironment. The tumor microenvironment is genetically stable and can be induced to an antitumor phenotype, which has significant therapeutic advantages. Studies have shown that SphK/S1P/S1PR can regulate multiple aspects of the tumor microenvironment. This review summarizes the effects of SphK and S1P/S1PR signaling on the tumor microenvironment from four perspectives: tumor immune microenvironment, cancer associated fibroblasts, tumor angiogenesis and tumor hypoxic microenvironment, and also outlines potential drug research related to these signal molecules, aiming to elucidate the role of SphK/S1P/S1PR in tumor occurrence and development and provide new ideas for the research of anti-tumor drugs.

Parkinson's disease (PD) is a degenerative disease of the central nervous system due to the loss or death of dopaminergic neurons in the substantia nigra. Clinically, levodopa is the most effective and commonly used drug for PD treatment. However, long-term levodopa therapy is prone to motor complications and other side effects caused by excessive peripheral dopamine production, which has become an urgent problem to be solved in PD treatment. Dopamine receptor (DR) agonists are similar to dopamine. They can directly stimulate postsynaptic dopamine receptors, produce the same effect as dopamine, delay the application of levodopa as much as possible, and reduce complications caused by long-term use of levodopa. Therefore, screening effective dopamine receptor agonists has become a key issue in the study and treatment of PD. In order to establish a rapid, stable and reliable method for dopamine receptor agonist screening, this study used the human dopamine receptor 2 (DRD2) gene fused with a circular permuted EGFP (cpEGFP) to construct a recombinant gene, packaged with lentiviral vector, and the vector replaced the parted inner transmembrane domain of the third intracellular loop (ICL3) of genetically-encoded GPCR-activation based (GRAB) sensors. The fluorescence of GPCR-fused cpEGFP is regulated by conformational changes mediated by the interaction of dopamine receptor agonists with GPCRs without altering GPCR activity. The HEK293T cells were infected with viral vector, screened by puromycin to select highly expressed cells. Dopamine receptor agonists (including dopamine, bromocriptine mesylate, cabergoline, pramipexole) were used as positive drugs to explore the best screening and detection conditions, establishing a stable model to evaluate the dopamine receptor agonist. The results showed that the optimal filter for the dopamine receptor agonist in this study was the cell seeding count of 7×10⁴, and the effective concentration of the positive drug was 1-100 µmol·L^-1. In addition, pretreated with 10 µmol·L^-1 dopamine receptor antagonists (including chlorprothixol hydrochloride, domperidone, and sulpiride), the positive fluorescence signal of overexpressed DRD2-cpEGFP HEK293T cells could not be detected when exposed to 10 µmol·L^-1 dopamine receptor agonists, which proved that dopamine receptor antagonists could block the activity of dopamine receptor agonists, so they cannot activate dopamine receptor allosteric, indicating that the model has good specificity and can also be used for the screening and detection of new dopamine receptor antagonists. In summary, the study constructs a stable dopamine sensor detection system, which can effectively screen potential dopamine receptor agonists. The operation procedures are simple and rapid. And it can be used for a large-scale screening providing a fundamental methodology for drug development and PD treatment targeted on DRD2.

The active ingredient of traditional Chinese medicine, silybin (SBN), can inhibit the proliferation of cancer cells and enhance the anticancer effect of doxorubicin (DOX). However, due to non-targeting and short half-life of SBN and DOX, as well as different administration routes and pharmacokinetic processes, this combination drug cannot act on the tumor in the set order, seriously eliminating the synergistic effect between them and limiting the effect in vivo. Therefore, we intended to construct a nano-delivery system based on molybdenum disulfide (MoS₂), modified by polyethylene glycol (PEG) and sialic acid (SA), and co-loaded with SBN and DOX. The system induced the release of combined drugs under the dual-stimulation of pH and near infra-red (NIR), increased the free concentration of intracellular drugs, so as to achieve the synergistic effect between them. The animal welfare and experimental procedures were in accordance with the regulations of the Animal Ethics Committee of Fujian University of Traditional Chinese Medicine. MoS₂-PEG-SA-SBN/DOX circulated in vivo, and effectively accumulated at tumor sites through enhanced permeability and retention effect (EPR) and SA-mediated active targeting. Under near infrared light irradiation, MoS₂-PEG-SA-SBN/DOX realized the combination of synergistic chemotherapy and photothermal therapy for tumor, thus achieving excellent anti-tumor effect in vivo. This study can provide a new idea and strategy for the clinical treatment of lung cancer. Taken together, MoS₂-PEG-SA-SBN/DOX can offer a new idea and strategy for the clinical treatment of lung cancer.

To study the chemical constituents and their biological activities in the rhizomes of Curcuma phaeocaulis, silica gel column chromatography, reverse medium pressure liquid chromatography, preparative thin layer chromatography, and semi-preparative high performance liquid chromatography were used for isolation and purification and modern spectroscopic methods were used to determine the structure of the isolated compound. Moreover, the effect of the compound on the proliferation of HUVECs was determined by the MTT assay. A new elemane-type sesquiterpenoid glycoside was isolated from the n-butanol soluble fraction of 95% ethanolic extract of the rhizomes of Curcuma phaeocaulis. Its structure was identified as (1Z)-2-hydroxy-curzerenone 2-O-β-D-glucoside. It showed no inhibitory effect on the proliferation of HUVECs.

The last essential enzyme in the biosynthetic pathway of trilobatin, phloretin-4'-O glycosyltransferase (P4'-OGT), catalyzes the conversion of trilobatin to phloretin in vitro. However, only a few P4'-OGTs have been found in plants. This study used Malus domestica phloretin-4'-O glycosyltransferase (MdPh-4'-OGT) as a query to identify and clone two UDP-glucuronosyltransferase (UGT) genes, designated UGT74L2 and UGT74L3, from the transcriptome of Andrographis paniculata. According to a phylogenetic tree analysis, UGT74L2 and UGT74L3 belonged to the UGT74 family, which has been linked to several activities in other species. The in vitro enzymatic reaction demonstrated that UGT74L2 could particularly catalyze the formation of trilobatin from phloretin, but UGT74L3 had no effects. By using Ni-NTA affinity chromatography to extract the soluble UGT74L2 recombinant protein, the enzymatic kinetics of the activity was investigated using phloretin as the substrate. The results showed that the optimal temperature and pH for UGT74L2 enzymatic reaction were 40 ℃ and 8.0 (Tris-HCl system), respectively. Three metal ions (Ca²⁺, Mn²⁺ and Co²⁺) showed inhibitory effect on the activity of UGT74L2, while Mg²⁺ could improve the activity of UGT74L2. Other tested metal ions have no significant effect on UGT74L2. The results of enzymatic kinetic parameters that the K_m value was 29.84 μmol·L^-1, the k_cat was 0.02 s^-1, and the k_cat·K_m^-1 was 572.6 mol^-1·s^-1. By homology modeling, molecular docking and mutation experiments, we found that multiple amino acids residues around the substrate binding pocket play quite an important role during catalytic process, In summary, we identified a novel P4'-OGT gene from medicinal plant Andrographis paniculata and provided a new efficient catalyst to synthesize trilobatin. Meanwhile, this study provides a reference for mining new efficient glycosylation modules from plants.

Protein-protein interaction (PPI) plays an important role in the regulation of life. Most of the PPI interfaces are large and discontinuous, and it is difficult for small molecules to specifically bind to them. Peptides are critical in PPI surface interactions due to their higher affinity and specificity. However, peptides have some defects such as easy hydrolysis by protease and poor membrane permeability. Due to good biocompatibility and chemical diversity, cyclic peptides play an important role in drug discovery. Therefore, the development of efficient cyclic peptide construction methods has become a frontier issue in peptide drug research. In recent years, a series of new progresses have been made in the synthesis strategy and the application of cyclic peptides, providing powerful technical tools for the research and development of cyclic peptide drugs. In this review, the synthesis strategies of cyclic peptides and their application will be reviewed from four aspects: synthesis strategies, property improvement, biological activity and prospect.