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.

The function of the central nervous system was significantly altered under high-altitude hypoxia, and these changes lead to central nervous system disease and affected the metabolism of drugs in vivo. The blood-brain barrier is essential for maintaining central nervous system stability and plays a key role in the regulation of drug metabolism, and barrier structure and dysfunction affect drug transport to the brain. Changes in the structure and function of the blood-brain barrier and the transport of drugs across the blood-brain barrier under high-altitude hypoxia are regulated by changes in brain microvascular endothelial cells, astrocytes and pericytes, and are regulated by drug metabolism factors such as drug transporters and drug metabolizing enzymes. This article reviews the effects of high-altitude hypoxia on the structure and function of the blood-brain barrier and the effects of changes in the blood-brain barrier on drug metabolism. We investigate the regulatory effects and underlying mechanisms of the blood-brain barrier and related pathways such as transcription factors, inflammatory factors and nuclear receptors on drug transport under high-altitude hypoxia.

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).

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.

Celastrol, extracted from Tripterygium wilfordii, is a natural pentacyclic triterpene compound, which has an anti-pulmonary fibrosis effect. However, its effect, binding targets and regulatory mechanism in pulmonary fibroblasts remain unclear. In this study, we found that celastrol could prevent fibroblast-myofibroblast transformation (FMT) by significantly inhibiting transforming growth factor β1 (TGFβ1)-induced α-smooth muscle actin and type Ⅰ collagen expression. Previous studies suggested that heat shock protein 60 (HSP60) may be the target of celastrol. This study confirmed the direct interaction between celastrol and HSP60 through cellular thermal shift assay and surface plasmon resonance experiment, and demonstrated that the K_D value of celastrol binding to HSP60 was 8.59 μmol·L^-1. Further studies showed that knockdown of HSP60 promoted TGFβ1-induced FMT, especially in the medium and low dose TGFβ1 treatment group, and that the anti-FMT effect of celastrol was significantly weakened after HSP60 knockdown. These results indicated that HSP60 was involved in maintaining the resting state of fibroblasts, and the anti-FMT effect of celastrol was dependent on HSP60. Furthermore, the autophagy promotion and antioxidant effects of celastrol were also weakened after HSP60 knockdown. In conclusion, celastrol inhibits FMT by targeting HSP60, thus exerting anti-pulmonary fibrosis function.

In this study, we explored the mechanism of Huganning tablet (HGNP) in the treatment of nonalcoholic fatty liver disease (NAFLD) based on network pharmacology and computer-aided drug design. Firstly, the potential ingredients and targets of HGNP were identified from TCMSP database, Swiss Target Prediction database, Chinese pharmacopoeia (2015) and literatures, and then the targets of HGNP intersected with NAFLD disease targets that obtained in GeneCards database to acquired potential targets. The bioconductor bioinformatics package of R software was used for gene ontology (GO) enrichment and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis. The network of "potential ingredient-key target-pathway" was formed in Cytoscape software to study the interactions between potential ingredients of HGNP, key targets, pathways and NAFLD. Based on the results of network pharmacology, the molecular docking analysis of the key targets and potential active ingredients in HGNP tablets with top degree in the network was conducted using Discovery Studio 2020 software, followed by molecular dynamics simulations, binding free energy calculation, drug-likeness properties analysis and ADMET (absorption, distribution, metabolism, excretion and toxicity) properties prediction. In vitro, HepG2 cells were used to establish steatosis model, and the effects of five key compounds on hepatocyte steatosis were analyzed by oil red O staining and triglyceride (TG) content determination. The results showed that 141 ingredients and 151 potential targets were obtained. A total of 2 526 items and 151 pathways were identified by GO and KEGG enrichment analysis. The molecular docking suggested that five components, isorhamnetin, salvianolic acid B, emodin, resveratrol and rhein, exhibited strong binding ability with key targets [retinoic acid receptor RXR-alpha (RXRA), tumor necrosis factor (TNF), glycogen synthase kinase-3 beta (GSK3B), serine/threonine-protein kinase 1 (AKT1)]. It was further verified that isorhamnetin and salvianolic acid B bind to key targets with good structural stability and binding affinity based on molecular dynamics simulations and binding free energy calculations. The drug-likeness properties, pharmacokinetic properties and toxicity of five key compounds were more comprehensively analyzed through drug-likeness properties analysis and ADMET properties prediction. In vitro, all five compounds, isorhamnetin, salvianolic acid B, emodin, resveratrol, and rhein, improved hepatocyte steatosis of HepG2 cells, confirming the reliability of the present study. In conclusion, based on network pharmacology, computer-aided drug design and in vitro validation, this study investigated the mechanism of HGNP for the treatment of NAFLD at multiple levels and provided a basis for its clinical application.

The cis-emodin-emodin dianthrone (compound 1) and trans-emodin-emodin dianthrone (compound 2) were extracted from Polygonum multiflorum Thunb. The protective effect and mechanism of compound 1 and compound 2 (emodin-emodin dianthrones) on acute liver injury induced by concanavalin A (ConA) in ICR mice was first investigated. The results indicated that emodin-emodin dianthrones at 1 mg·kg^-1 significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) level (P < 0.05). Emodin-emodin dianthrones also improved liver histopathological damage in liver-injured mice. The level of Bcl-2-associated X protein (Bax) mRNA in liver was significantly reduced by 1 mg·kg^-1 of emodin-emodin dianthrones, while the level of B-cell lymphoma-2 (Bcl-2) mRNA expression was significantly increased (P < 0.05). The protective activity of compounds 1 and 2 against hepatocyte injury was further evaluated by hydrogen peroxide (H₂O₂)-induced hepatocyte injury. Compounds 1 and 2 significantly inhibited H₂O₂-induced hepatocyte injury and reduced the levels of ALT, AST, alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) in cell culture. Compounds 1 and 2 also significantly improved the cell survival rate and decreased H₂O₂-induced oxidative stress in hepatocytes. Compound 1 (0.5 µmol·L^-1) significantly increased the enzymatic activity of superoxide dismutase (SOD) in hepatocytes (P < 0.01), and 0.5 µmol·L^-1 of compound 2 significantly decreased the intracellular reactive oxygen species (ROS), increased SOD enzyme activity, and glutathione (GSH) content (P < 0.01). Compounds 1 and 2 at 0.5 µmol·L^-1 also inhibited hepatocyte apoptosis by increasing the protein expression ratio of Bcl-2/Bax (P < 0.05) and decreasing the protein expression ratio of cleaved caspase-3 and pro caspase-3 (P < 0.05). This study indicates that the emodin-emodin dianthrones from Polygonum multiflorum Thunb. have liver-protective activity. Compounds 1 and 2 exerted hepatoprotective effects by inhibiting apoptosis and oxidative stress. The study provides an important material basis for the hepatoprotective effect of commonly used amounts of Polygonum multiflorum Thunb.

By using computer-aided drug design, the activities group model which CDK4/6 inhibitors on the market were introduced to silybin C-7, and a series of silybin derivatives were designed and synthesized, and the structure was confirmed by MS, ¹³C NMR and ¹H NMR. The in vitro antitumor activity evaluation of the target compound was carried out by MTT method, and the in vitro anti-tumor activity was carried out in human hepatocellular carcinoma cells (HepG-2). Experimental results show that all compounds are higher than the activity of the parent silybin, of which compound I₁ has a certain inhibitory effect on human HepG-2 cells, which is worth further study.

Fifteen compounds were isolated from the 95% ethanol extract of the whole plant of Elephantopus tomentosus L. by silica gel column chromatography, Sephadex LH-20 column chromatography, MCI column chromatography and semi-preparative HPLC methods. Their structures were identified on the basis of physicochemical properties, and spectral data (UV, IR, NMR, MS and CD) analysis as tomenlephanlide A (1), molephantinin (2), molephantin (3), 8-O-methacryloylelephanpane (4), apigenin (5), tricin (6), 2-phenyl acetamide (7), 3, 4-dihydroxybenzoic acid methyl ester (8), caffeic acid methyl ester (9), caffeic acid ethyl ester (10), (+)-(4S)-(2E)-4-hydroxy-2-nonenoic acid (11), E-4-hydroxyhex-2-enoic acid (12), 1H-indole-3-carboxylic acid (13), 1H-indole-3-carbaldehyde (14) and isohematinic acid (15). Among them, compound 1 is a new germacrene-type sesquiterpenoid, 5-15 were obtained from E. tomentosus L. for the first time. It was the first time the absolute configuration of compound 2 was reported. Compound 1 showed weak cytotoxicity against gastric cancer cells (SGC-7901).

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.