Latest ArticlesAtopic dermatitis (AD) is a chronic, relapsing, inflammatory dermatosis with a variety of clinical manifestations and difficult to cure. Currently, many AD drug candidates have entered the research and development pipeline. In order to provide technical specifications for the clinical development of AD drugs, the Center for Drug Evaluation of National Medical Products Administration released the "Technical Guidelines for Clinical Trials of Drugs for AD Treatment" (Draft for Comments) in November 2022. Non-clinical pharmacodynamics evaluation is an important research before the drug enters clinical trials. Oxazolone (OXA)- and 2, 4-dinitro-fluorobenzene (DNFB)-induced models are the most popular classical hapten-induced AD murine models, but variations of modeling are existing in the methods from different studies, including sensitization sites, haptens' dosages, the period of challenges, and the skin lesions severity evaluation as well. In this study, the investigation of OXA- and DNFB-induced AD murine models with various conditions of modeling was performed to compare the characteristics of hapten-induced AD murine models in the pathological process and severity according to the appearance of AD patients, and the guidance of pharmacodynamics evaluation of AD-therapeutic drugs in clinical trials as well, which may provide a proposal for AD treatment drug candidates in the non-clinical pharmacodynamics evaluation. All animal experiments were approved by the Animal Care & Welfare Committee of Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College (approval No.: 00007782 and 00007784).
Artemisinin is a sesquiterpene lactone natural product that contains an endoperoxide bond. Artemisinin has various biological activities including antimalarial, anti-tumor, antiviral and anti-fibrotic activity. Owing to the poor pharmacokinetic properties of artemisinin, its derivatives are currently used in clinic and frequently reported in literature. Although numerous derivatives of artemisinin have been reported, no study has been carried out yet to study the effect of substituted groups with different acid-base property on the antimalarial activity. Among these derivatives, the C-10 carbon artemisinin derivatives are often reported, and their corresponding 10β epimer show much better antimalarial activity than 10α epimer with large-sized substitute. However, there is currently no stereoselective synthesis to efficiently prepare the privileged 10β epimer of C-10 carba artemisinin. To address these two scientific questions, we herein first report an optimized method to stereoselectively synthesize the 10β epimer of C-10 carba artemisinin (98∶2 d.r.). Second, we employed the optimized method to synthesize a series of C-10 carba artemisinin derivatives with different acid-base properties. The antimalarial examination indicated that those derivatives with neutral groups or basic group of short chain showed similar antimalarial activity as dihydroartemisinin (DHA). The acidic group could dramatically decrease the antimalarial effect and was more than 22-fold less effective than DHA or the neutral ones. This study will shed light on the development of new generation of artemisinin derivatives with potent activity.
A pharmacophore-based study was conducted to investigate the therapeutic activity of the traditional Tibetan medicine Zha Xun (ZX) in liver diseases. In the present study, the protective effect of ZX on the acute liver injury induced by concanavalin A (ConA) and 0.15% carbon tetrachloride (0.15% CCl4) in ICR mice was evaluated, and the results showed that ZX significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the ConA-induced acute immune liver injury model and the CCl4-induced acute oxidative liver injury model (P < 0.05). Subsequently, the protective effects of aqueous, 95% ethanol, 60% ethanol and 30% ethanol eluting fractions of ZX, and fulvic acid, the main water-soluble constituent of ZX, were evaluated against acute oxidative liver injury induced by 0.15% CCl4 in mice. The results showed that different solvent-eluting fractions of ZX showed certain hepatoprotective activities, among which the aqueous extract of ZX and 30% ethanol extract of ZX significantly reduced the serum levels of ALT, AST, and lactate dehydrogenase (LDH) in mice (P < 0.05), and the serum levels of LDH in mice were significantly reduced by fulvic acid (P < 0.05), which showed significant hepatoprotective activity. The protective activities and preliminary mechanisms of the total extract of ZX, the aqueous extract of ZX, the 30% ethanol extract of ZX, and fulvic acid against hepatocellular injury in vitro were further evaluated by using the H2O2-induced hepatocellular injury model. The results showed that the components could significantly inhibit H2O2-induced hepatocellular injury, reduce the levels of ALT, alkaline phosphatase (ALP), and LDH, improve the survival rate of hepatocellular cells, and reduce the content of intracellular reactive oxygen species (ROS) in cell culture. At the same time, it can inhibit hepatocyte apoptosis by increasing the expression ratio of Bcl-2/BAX protein and decreasing the expression ratio of cleaved caspase-3/pro caspase-3 protein. The present study showed that ZX has clear hepatoprotective activity in vitro and in vivo, and the different solvent elution fractions of ZX showed certain hepatoprotective activity, among which the aqueous extract of ZX, 30% ethanol extract of ZX had better hepatoprotective activity, and the activity of 60% ethanol extract of ZX was stronger than that of 95% ethanol extract of ZX. The activity of ZX and its water-soluble elution site exerted hepatoprotective effects by inhibiting hepatocyte apoptosis and oxidative stress. The animals used in this experiment and related disposal meet the requirements of animal welfare, and have been reviewed and approved by the Laboratory Animal Management and Use Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences (approval number: 00004018).
Three new anthraquinones were isolated from the 80% ethanol extract of Prismatomeris tetrandra by silica gel, MCI, ODS column chromatography and high performance preparative liquid chromatography (HPLC). The structures of the new compounds were identified by mass spectrometry, nuclear magnetic resonance and other spectroscopic methods as 6-hydroxy-1,2,3-trimethoxy-7-methylanthracene-9,10-dione (1), 6-(hydroxymethyl)-1,2,3-trimethoxyanthracene-9,10-dione (2) and 7-hydroxy-6-(hydroxymethyl)-1,2-dimethoxyanthracene-9,10-dione (3). Compounds 1, 2 and 3 showed protective effects against monosodium glutamate-induced damage in SH-SY5Y neuroblastoma cells, with the cell survival rates elevated 18.45%, 4.31%, and 7.65%, respectively.
Gut microbial metabolite trimethylamine-N-oxide (TMAO) is associated with type 2 diabetes (T2DM). Decreased insulin sensitivity is a significant etiological factor of T2DM. Adipocytes, myocytes, and hepatocytes are the three major target cells for insulin. This study aims to investigate the effects and mechanisms of TMAO on the insulin sensitivity of these target cells. Research results indicate that in different ages of db/db diabetic mice, plasma TMAO levels were increased. TMAO significantly inhibits the insulin signaling pathways in these three major insulin target cells, reduces glucose uptake in 3T3-L1 adipocytes and L6 myocytes and downregulates genes related to gluconeogenesis in primary mouse hepatocytes. Furthermore, in mice with normal insulin sensitivity, elevating plasma TMAO levels to those seen in db/db mice using a minipump results in impaired glucose tolerance and hyperinsulinemia. All animal experiments were carried out with approval of the Experimental Animal Welfare Ethics Committee of the Institute of Materia Medica (Chinese Academy of Medical Sciences and Peking Union Medical College). Mechanistic studies suggest that TMAO exposure increases the levels of endoplasmic reticulum stress-related proteins in these three major insulin target cells. In summary, TMAO directly attenuates insulin sensitivity in insulin target cells, and its mechanism of action may involve enhancing endoplasmic reticulum stress.
Protein tyrosine phosphatase (PTP) 1B is a potential therapeutic target for type 2 diabetes. Phosphotyrosine (pTyr) mimetics still dominate the currently available PTP1B inhibitors. The phenoxyacetic acid moiety was taken as a pTyr mimetic herein and phenoxyacetic acid-based compounds 2a-2g and 3a-3c were designed. Among them, compounds 2a-2g exhibited potent inhibition against PTP1B, and compound 2g showed an IC50 of 0.42 μmol·L-1 against PTP1B. Compound 2f exhibited pharmacological profiles similar to that of rosiglitazone, and could improve the insulin sensitivity and the serum total cholesterol level. The results suggest that PTP1B inhibitors might be effective in treating type 2 diabetes as well as associated metabolic syndromes.
Ramulus Mori (Sangzhi) alkaloids (SZ-A) are a group of polyhydroxy alkaloids extracted and isolated from the traditional Chinese medicine mulberry twig, which is mainly used for the treatment of type 2 diabetes mellitus (T2DM). In addition to acting as a glycosidase inhibitor in the small intestine after oral administration, SZ-A can also be absorbed into blood and widely distributed to target organs related to diabetes, exerting multiple pharmacological effects. It is important to elucidate the possible pharmacokinetic influences of SZ-A for its clinical rational applications, such as drug interactions, the effects of food and alcohol on the absorption of SZ-A. However, studies in this area are limited. Therefore, the pharmacokinetic interactions between orally administrated SZ-A (50 mg·kg-1) and metformin hydrochloride (Met, 200 mg·kg-1) in Sprague-Dawley (SD) rats were examined. Then, the effect of food (standard feed) on the pharmacokinetics of SZ-A was investigated using fasting administration of SZ-A (50 mg·kg-1) in rats as a control. Finally, we investigated the pharmacokinetic characteristics of SZ-A (50 mg·kg-1) in different concentrations alcohol solutions using aqueous solution of SZ-A administered to rats as a control to evaluate the effect of alcohol on the bioabsorption of SZ-A. The results showed no significant pharmacokinetic interactions between SZ-A and Met after combination treatment. The standard feed had little effect on the pharmacokinetic profile of SZ-A. Alcohol retarded the absorption of SZ-A, resulting in a significant decrease in the Cmax of SZ-A. The decrease was greater at higher alcohol concentrations; however, no significant difference was observed in the AUC0-t. These results support the clinical rational applications of SZ-A. All animal protocols were approved by the Ethics Committee of Kangtai Medical Laboratory Service Hebei Co., Ltd. (Hebei, China) (No. MDL2022-01-17-1).
Alternative splicing of pre-messenger RNA (pre-mRNA) is a crucial mechanism for the diversity of the human transcriptome and proteome. Alternative splicing is a complex gene regulation process. Whole-transcriptome analysis shows that 95% of human exonic genes are alternatively spliced, involving various cis-acting elements and trans-acting factors. Any changes in any component or step may cause erroneous splicing events and lead to the occurrence of various related diseases. In addition to gene replacement therapy that directly changes the splicing results, RNA splicing modification is expected to become a new therapeutic strategy to alleviate or treat diseases by targeting and correcting abnormal pre-mRNA splicing. Splicing modification tools currently developed including RNA trans-splicing, antisense oligonucleotides, small interfering RNA, and small molecule drugs can correct abnormal splicing through different ways. This article reviews the resent progress of epigenetic regulation of pre-mRNA alternative splicing in recent years, and discusses the occurrence and regulation of alternative splicing, the types of diseases caused by related splicing defects, and the current-used tools for targeting and altering splicing. The importance of splicing modification strategies in the future treatment of human diseases is envisioned.
Quantitative nuclear magnetic resonance (qNMR) technology has significant advantages in quantification due to its simple sample processing and high reproducibility. Two-dimensional qNMR analysis, which can solve the quantification problem of different components in complex systems, has gradually been applied in medicine, food, metabonomics, chemical engineering, and other fields. This paper reviews the analysis methods, influencing factors, experimental optimization, application fields, and other aspects of qNMR to promote its wide and effective application.
This study assessed and explored the pharmacological effects and mechanisms of action of IMMH002 {2-amino-2-(2-(4ʹ-(2-ethyloxazol-4-yl)-[1, 1ʹ-biphenyl]-4-yl)ethyl)propane-1, 3-dio}, a selective sphingosine-1-phosphate receptor subtype 1 (S1P1) modulator, in a concanavalin A (ConA)-induced autoimmune hepatitis (AIH) mouse model. The experimental protocol strictly adhered to the guidelines of the Ethics Committee for Animal Research of the Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College (Approval No.: 00004046). Male ICR mice were pre-treated with the drug for four days, followed by induction of AIH through tail vein injection of ConA protein. Liver function, hepatic tissue pathology, peripheral blood parameters, as well as immunoglobulin G (IgG), inflammatory cytokines, T cell distribution, and inflammatory pathways were evaluated in mice. Results demonstrated that IMMH002 significantly reduced liver function indicators such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), alleviated hepatic tissue inflammation and necrotic damage, decreased serum IgG levels, and lowered the expression of inflammatory mediators including interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and interferon γ (IFN-γ). Additionally, it facilitated T lymphocyte homing, downregulated the phosphorylation of nuclear factor kappa-B (NF-κB), IκB kinase β (IKKβ) and nuclear factor inhibitor protein-α (IκBα) proteins in hepatic tissue and cellular inflammation models. Collectively, IMMH002 effectively ameliorated ConA-induced autoimmune hepatitis in mice, exhibiting extensive anti-inflammatory and anti-necrotic effects, thereby laying a theoretical foundation for AIH clinical treatment.