A comprehensive review on celastrol, triptolide and triptonide: Insights on their pharmacological activity, toxicity, combination therapy, new dosage form and novel drug delivery routes

Celastrol induces DNA damage and cell death in BCR-ABL T315I-mutant CML by targeting YY1 and HMCES

BACKGROUND

Chronic myeloid leukemia (CML) is driven primarily by the constitutively active BCR-ABL fusion oncoprotein. Although the development of tyrosine kinase inhibitors has markedly improved the prognosis of CML patients, it remains a significant challenge to overcome drug-resistant mutations, such as the T315I mutation of BCR-ABL, and achieve treatment-free remission in the clinic.

PURPOSE

The identification of new intervention targets beyond BCR-ABL could provide new perspectives for future research and therapeutic intervention. A network pharmacology analysis was conducted to identify the most promising natural product with anti-CML activity. Celastrol was selected for further analysis to gain insights into its mechanism of action (MoA), with the aim of identifying potential new intervention targets for BCR-ABL T315I-mutant CML.

METHODS

Transcriptomic and proteomic analyses were conducted to systematically investigate the molecular MoA of celastrol in K562T315I cells. To identify the target proteins of celastrol, mass spectrometry-coupled cellular thermal shift assay (MS-CETSA) was carried out, followed by validations with genetic knockdown and overexpression, cell proliferation assay, comet assay, Western blotting, celastrol probe-based in situ labeling and pull-down assay, molecular docking, and biolayer interferometry.

RESULTS

Our multi-omics analyses revealed that celastrol primarily induces DNA damage accumulation and the unfolded protein response in K562T315I cells. Among the twelve most potential celastrol targets, experimental evidence demonstrated that the direct interaction of celastrol with YY1 and HMCES increases the levels of DNA damage, leading to cell death.

CONCLUSION

This study represents the first investigation utilizing a proteome-wide label-free target deconvolution approach, MS-CETSA, to identify the protein targets of celastrol. This study also develops a new systems pharmacology strategy. The findings provide new insights into the multifaceted mechanisms of celastrol and, more importantly, highlight the potential of targeting proteins in DNA damage and repair pathways, particularly YY1 and HMCES, to combat drug-resistant CML.

Hepatoma-Targeting and ROS-Responsive Polymeric Micelle-Based Chemotherapy Combined with Photodynamic Therapy for Hepatoma Treatment

Background

The combination of nanoplatform-based chemotherapy and photodynamic therapy (PDT) is a promising way to treat cancer. Celastrol (Cela) exhibits highly effective anti-hepatoma activity with low water solubility, poor bioavailability, non-tumor targeting, and toxic side effects. The combination of Cela-based chemotherapy and PDT via hepatoma-targeting and reactive oxygen species (ROS)-responsive polymeric micelles (PMs) could solve the application problem of Cela and further enhance antitumor efficacy.

Methods

In this study, Cela and photosensitizer chlorin e6 (Ce6) co-loaded glycyrrhetinic acid-modified carboxymethyl chitosan-thioketal-rhein (GCTR) PMs (Cela/Ce6/GCTR PMs) were prepared and characterized. The safety, ROS-sensitive drug release, and intracellular ROS production were evaluated. Furthermore, the in vitro anti-hepatoma effect and cellular uptaken in HepG2 and BEL-7402 cells, and in vivo pharmacokinetic, tissue distribution, and antitumor efficacy of Cela/Ce6/GCTR PMs in H22 tumor-bearing mice were then investigated.

Results

Cela/Ce6/GCTR PMs were successfully prepared with nanometer-scale particle size, favorable drug loading capacity, and encapsulation efficiency. Cela/Ce6/GCTR PMs exhibited a strong safety profile and better hemocompatibility, exhibiting less damage to normal tissues. Compared with Cela-loaded GCTR PMs, the ROS-responsiveness of Cela/Ce6/GCTR PMs was increased, and the release of Cela was accelerated after combination with PDT. Cela/Ce6/GCTR PMs can efficiently target liver tumor cells by uptake and have a high cell-killing effect in response to ROS. The combination of GCTR PM-based chemotherapy and PDT resulted in increased bioavailability of Cela and Ce6, improved liver tumor targeting, and better anti-hepatoma effects in vivo.

Conclusion

Hepatoma-targeting and ROS-responsive GCTR PMs co-loaded with Cela and Ce6 combined with PDT exhibited improved primary hepatic carcinoma therapeutic effects with lower toxicity to normal tissues, overcoming the limitations of monotherapy and providing new strategies for tumor treatment.

Integrative Chinese-Western medicine strategy to overcome docetaxel resistance in prostate cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese Medicines (TCMs) have emerged as a promising complementary therapy in the management of prostate cancer (PCa), particularly in addressing resistance to Docetaxel (DTX) chemotherapy.

AIM OF THE REVIEW

This review aims to elucidate the mechanisms underlying the development of resistance to DTX in PCa and explore the innovative approach of integrating TCMs in PCa treatment to overcome this resistance. Key areas of investigation include alterations in microtubule proteins, androgen receptor and androgen receptor splice variant 7, ERG rearrangement, drug efflux mechanisms, cancer stem cells, centrosome clustering, upregulation of the PI3K/AKT signaling pathway, enhanced DNA damage repair capability, and the involvement of neurotrophin receptor 1/protein kinase C.

MATERIALS AND METHODS

With "Prostate cancer", "Docetaxel", "Docetaxel resistance", "Natural compounds", "Traditional Chinese medicine", "Traditional Chinese medicine compound", "Medicinal plants" as the main keywords, PubMed, Web of Science and other online search engines were used for literature retrieval.

RESULTS

Our findings underscore the intricate interplay of molecular alterations that collectively contribute to the resistance of PCa cells to DTX. Moreover, we highlight the potential of TCMs as a promising complementary therapy, showcasing their ability to counteract DTX resistance and enhance therapeutic efficacy.

CONCLUSION

The integration of TCMs in PCa treatment emerges as an innovative approach with significant potential to overcome DTX resistance. This review not only provides insights into the mechanisms of resistance but also presents new prospects for improving the clinical outcomes of patients with PCa undergoing DTX therapy. The comprehensive understanding of these mechanisms lays the foundation for future research and the development of more effective therapeutic interventions.

Screening, identification and targeted intervention of necroptotic biomarkers of asthma

BACKGROUND

As a pivotal pathway of programmed cell death, necroptosis significantly contributes to the pathogenesis of respiratory disorders. However, its role in asthma is not yet fully elucidated. Therefore, this study aimed to identify markers associated with necroptosis, evaluate their functions in asthma, and explore potential therapeutic agents targeting necroptosis for the management of asthma.

METHODS

Firstly, machine learning algorithms, including Least Absolute Shrinkage and Selection Operator (LASSO), Random Forest, and Support Vector Machine-Recursive Feature Elimination (SVM-RFE), were utilized to identify necroptosis-related differentially expressed genes (NRDEGs) in asthma patients compared to healthy controls. Concurrently, the expression of NRDEGs was validated using external datasets, Western blot, and quantitative real-time polymerase chain reaction (qPCR). Secondly, the clinical relevance of NRDEGs was assessed through Receiver Operating Characteristic (ROC) curve analysis and correlation with clinical indicators. Thirdly, the relationship between NRDEGs and pulmonary immune cell infiltration, as well as the signaling interactions between different cells types, were analyzed through immune infiltration and single-cell analysis. Fourthly, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA), were conducted to elucidate the functional roles of NRDEGs. Finally, compounds targeting NRDEGs were screened, and their binding affinities were evaluated using molecular docking studies.

RESULTS

In asthma, necroptosis is activated, leading to the identification of four NRDEGs: NLRP3, PYCARD, ALOX15, and VDAC3. Among these, NLRP3, PYCARD, and ALOX15 are upregulated, whereas VDAC3 is downregulated in asthma. Comprehensive clinical evaluations indicated that NRDEGs hold diagnostic value for asthma. Specifically, NLRP3 was inversely correlated with forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), while VDAC3 showed an inverse correlation with sputum neutrophils. Conversely, ALOX15 expression was positively correlated with fractional exhaled nitric oxide (FeNO) levels, as well as sputum eosinophils, blood eosinophils, and blood IgE levels. Subsequent immune infiltration analysis revealed associations between NRDEGs and activated dendritic cells, mast cells, and eosinophils. Single-cell RNA sequencing (scRNA-seq) further confirmed the communication signals between myeloid dendritic cells, fibroblasts, neutrophils, and helper T cells, predominantly related to fibrosis and immune-inflammatory responses. Pathway enrichment analysis demonstrated that NRDEGs are involved in ribosomal function, oxidative phosphorylation, and fatty acid metabolism. Finally, resveratrol and triptonide were identified as potential therapeutic agents targeting the proteins encoded by NRDEGs for asthma treatment.

CONCLUSIONS

The necroptosis pathway is activated in asthma, with NRDEGs-namely PYCARD, NLRP3, ALOX15, and VDAC3-correlated with declines in lung function and airway inflammation. These genes serve as reliable predictors of asthma risk and are involved in the regulation of the immune-inflammatory microenvironment. Resveratrol and triptolide have been identified as promising therapeutic candidates due to their potential to target the proteins encoded by these genes.

Recent developments and new directions in the use of natural products for the treatment of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) represents a significant global health challenge, and there is an urgent need to explore novel therapeutic interventions. Natural products have demonstrated highly promising effectiveness in the treatment of IBD.

PURPOSE

This study systematically reviews the latest research advancements in leveraging natural products for IBD treatment.

METHODS

This manuscript strictly adheres to the PRISMA guidelines. Relevant literature on the effects of natural products on IBD was retrieved from the PubMed, Web of Science and Cochrane Library databases using the search terms "natural product," "inflammatory bowel disease," "colitis," "metagenomics", "target identification", "drug delivery systems", "polyphenols," "alkaloids," "terpenoids," and so on. The retrieved data were then systematically summarized and reviewed.

RESULTS

This review assessed the different effects of various natural products, such as polyphenols, alkaloids, terpenoids, quinones, and others, in the treatment of IBD. While these natural products offer promising avenues for IBD management, they also face challenges in terms of clinical translation and drug discovery. The advent of metagenomics, single-cell sequencing, target identification techniques, drug delivery systems, and other cutting-edge technologies heralds a new era in overcoming these challenges.

CONCLUSION

This paper provides an overview of current research progress in utilizing natural products for the treatment of IBD, exploring how contemporary technological innovations can aid in discovering and harnessing bioactive natural products for the treatment of IBD.

Crosstalk between ROS-inflammatory gene expression axis in the progression of lung disorders

A significant number of deaths and disabilities worldwide are brought on by inflammatory lung diseases. Many inflammatory lung disorders, including chronic respiratory emphysema, resistant asthma, resistance to steroids, and coronavirus-infected lung infections, have severe variants for which there are no viable treatments; as a result, new treatment alternatives are needed. Here, we emphasize how oxidative imbalance contributes to the emergence of provocative lung problems that are challenging to treat. Endogenic antioxidant systems are not enough to avert free radical-mediated damage due to the induced overproduction of ROS. Pro-inflammatory mediators are then produced due to intracellular signaling events, which can harm the tissue and worsen the inflammatory response. Overproduction of ROS causes oxidative stress, which causes lung damage and various disease conditions. Invasive microorganisms or hazardous substances that are inhaled repeatedly can cause an excessive amount of ROS to be produced. By starting signal transduction pathways, increased ROS generation during inflammation may cause recurrent DNA damage and apoptosis and activate proto-oncogenes. This review provides information about new targets for conducting research in related domains or target factors to prevent, control, or treat such inflammatory oxidative stress-induced inflammatory lung disorders.

Triptolide-induced cuproptosis is a novel antitumor strategy for the treatment of cervical cancer

BACKGROUND

Cuproptosis is a unique copper-dependent form of cell death that is highly correlated with the metabolic state of cells. Triptolide exerts pharmacological activity by altering the regulation of metal ions. Cuproptosis is poorly understood in cancer, so in this study, we explored whether triptolide could induce cuproptosis in cervical cancer cells.

METHODS

The human cervical cancer cell lines HeLa and SiHa, which primarily rely on oxidative phosphorylation, were treated with triptolide. Cell viability, proliferation and migration, copper levels and cuproptosis-related protein levels were evaluated in these cell lines. The copper ion chelator tetrathiomolybdate (TTM) was administered to determine whether it could reverse the cuproptosis induced by triptolide. In addition, a nude mouse cervical cancer xenograft model was established to determine the effects of triptolide on cuproptosis in isolated tumor tissues.

RESULTS

The copper concentration increased with triptolide treatment. The levels of cuproptosis -related proteins, such as FDX1, LIAS, and DLAT, in the HeLa and SiHa cell lines decreased with triptolide treatment. XIAP, the target of triptolide, played a role in cuproptosis by regulating COMMD1. The level of copper exporters (ATP7A/B) decreased, but the level of the copper importer (CTR1) did not change with triptolide treatment. Furthermore, triptolide inhibited cervical cancer growth and induced cuproptosis in vivo.

CONCLUSIONS

In summary, we report a new antitumor mechanism by which triptolide disrupted intracellular copper homeostasis and induced cuproptosis in cervical cancer by regulating the XIAP/COMMD1/ATP7A/B axis.

PTEN status determines therapeutic vulnerability to celastrol in cholangiocarcinoma

BACKGROUND

A balanced protein homeostasis network helps cholangiocarcinoma (CCA) maintain their oncogenic growth, and disrupting proteostasis therapeutically will induce proteotoxic stress. Phosphatase and tensin homolog (PTEN) have been reported to be involved in proteostasis, and PTEN-associated pathways are commonly altered in CCA. Celastrol, a triterpene from plants, exhibits cytotoxic effects in various types of cancer. However, the underlying mechanisms remain unclear.

PURPOSE

We investigated the therapeutic effect of celastrol in CCA and identified the molecular characteristics of tumors that were sensitive to celastrol. The target of celastrol was explored. We then evaluated the candidate combination therapeutic strategy to increase the effectiveness of celastrol in celastrol-insensitive CCA tumors.

METHODS

Various CCA cells were categorized as either celastrol-sensitive or celastrol-insensitive based on their response to celastrol. The molecular characteristics of cells from different groups were determined by RNA-seq. PTEN status and its role in proteasome activity in CCA cells were investigated. The CMAP analysis, molecular docking, and functional assay were performed to explore the effect of celastrol on proteasome activities. The correlation between PTEN status and clinical outcomes, as well as proteasomal activity, were measured in CCA patients. The synergistic therapeutic effect of autophagy inhibitors on celastrol-insensitive CCA cells were measured.

RESULTS

Diverse responses to celastrol were observed in CCA cells. PTEN expression varied among different CCA cells, and its status could impact cell sensitivity to celastrol: PTENhigh tumor cells were resistant to celastrol, while PTENlow cells were more sensitive. Celastrol induced proteasomal dysregulation in CCA cells by directly targeting PSMB5. Cells with low PTEN status transcriptionally promoted proteasome subunit expression in an AKT-dependent manner, making these cells more reliant on proteasomal activities to maintain proteostasis. This caused the PTENlow CCA cells sensitive to celastrol. A negative correlation was found between PTEN levels and the proteasome signature in CCA patients. Moreover, celastrol treatment could induce autophagy in PTENhigh CCA cells. Disrupting the autophagic pathway in PTENhigh CCA cells enhanced the cytotoxic effect of celastrol.

CONCLUSION

PTEN status in CCA cells determines their sensitivity to celastrol, and autophagy inhibitors could enhance the anti-tumor effect in PTENhigh CCA.

Natural products with anti-tumorigenesis potential targeting macrophage

BACKGROUND

Inflammation is a risk factor for tumorigenesis. Macrophage, a subset of immune cells with high plasticity, plays a multifaceted role in this process. Natural products, which are bioactive compounds derived from traditional herbs or foods, have exhibited diverse effects on macrophages and tumorigenesis making them a valuable resource of drug discovery or optimization in tumor prevention.

PURPOSE

Provide a comprehensive overview of the various roles of macrophages in tumorigenesis, as well as the effects of natural products on tumorigenesis by modulating macrophage function.

METHODS

A thorough literature search spanning the past two decades was carried out using PubMed, Web of Science, Elsevier, and CNKI following the PRISMA guidelines. The search terms employed included "macrophage and tumorigenesis", "natural products, macrophages and tumorigenesis", "traditional Chinese medicine and tumorigenesis", "natural products and macrophage polarization", "macrophage and tumor related microenvironment", "macrophage and tumor signal pathway", "toxicity of natural products" and combinations thereof. Furthermore, certain articles are identified through the tracking of citations from other publications or by accessing the websites of relevant journals. Studies that meet the following criteria are excluded: (1) Articles not written in English or Chinese; (2) Full texts were not available; (3) Duplicate articles and irrelevant studies. The data collected was organized and summarized based on molecular mechanisms or compound structure.

RESULTS

This review elucidates the multifaceted effect of macrophages on tumorigenesis, encompassing process such as inflammation, angiogenesis, and tumor cell invasion by regulating metabolism, non-coding RNA, signal transduction and intercellular crosstalk. Natural products, including vitexin, ovatodiolide, ligustilide, and emodin, as well as herbal remedies, have demonstrated efficacy in modulating macrophage function, thereby attenuating tumorigenesis. These interventions mainly focus on mitigating the initial inflammatory response or modifying the inflammatory environment within the precancerous niche.

CONCLUSIONS

These mechanistic insights of macrophages in tumorigenesis offer valuable ideas for researchers. The identified natural products facilitate the selection of promising candidates for future cancer drug development.

Celastrol enhances the viability of random-pattern skin flaps by regulating autophagy through the AMPK-mTOR-TFEB axis

In reconstructive and plastic surgery, random-pattern skin flaps (RPSF) are often used to correct defects. However, their clinical usefulness is limited due to their susceptibility to necrosis, especially on the distal side of the RPSF. This study validates the protective effect of celastrol (CEL) on flap viability and explores in terms of underlying mechanisms of action. The viability of different groups of RPSF was evaluated by survival zone analysis, laser doppler blood flow, and histological analysis. The effects of CEL on flap angiogenesis, apoptosis, oxidative stress, and autophagy were evaluated by Western blot, immunohistochemistry, and immunofluorescence assays. Finally, its mechanistic aspects were explored by autophagy inhibitor and Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) inhibitor. On the seventh day after surgery, the survival area size, blood supply, and microvessel count of RPSF were augmented following the administration of CEL. Additionally, CEL stimulated angiogenesis, suppressed apoptosis, and lowered oxidative stress levels immediately after elevated autophagy in ischemic regions; These effects can be reversed using the autophagy inhibitor chloroquine (CQ). Specifically, CQ has been observed to counteract the protective impact of CEL on the RPSF. Moreover, it has also been discovered that CEL triggers the AMPK-mTOR-TFEB axis activation in the area affected by ischemia. In CEL-treated skin flaps, AMPK inhibitors were demonstrated to suppress the AMPK-mTOR-TFEB axis and reduce autophagy levels. This investigation suggests that CEL benefits the survival of RPSF by augmenting angiogenesis and impeding oxidative stress and apoptosis. The results are credited to increased autophagy, made possible by the AMPK-mTOR-TFEB axis activation.

Triptolide decreases podocytes permeability by regulating TET2-mediated hydroxymethylation of ZO-1

Podocyte injury or dysfunction can lead to proteinuria and glomerulosclerosis. Zonula occludens 1 (ZO-1) is a tight junction protein which connects slit diaphragm (SD) proteins to the actin cytoskeleton. Previous studies have shown that the expression of ZO-1 is decreased in chronic kidney disease (CKD). Thus, elucidation of the regulation mechanism of ZO-1 has considerable clinical importance. Triptolide (TP) has been reported to exert a strong antiproteinuric effect by inhibiting podocyte epithelial mesenchymal transition (EMT) and inflammatory response. However, the underlying mechanisms are still unclear. We found that TP upregulates ZO-1 expression and increases the fluorescence intensity of ZO-1 in a puromycin aminonucleoside (PAN)-induced podocyte injury model. Permeablity assay showed TP decreases podocyte permeability in PAN-treated podocyte. TP also upregulates the DNA demethylase TET2. Our results showed that treatment with the DNA methyltransferase inhibitors 5-azacytidine (5-AzaC) and RG108 significantly increased ZO-1 expression in PAN-treated podocytes. Methylated DNA immunoprecipitation (MeDIP) and hydroxymethylated DNA immunoprecipitation (hMeDIP) results showed that TP regulates the methylation status of the ZO-1 promoter. Knockdown of TET2 decreased ZO-1 expression and increased methylation of its promoter, resulting in the increase of podocyte permeability. Altogether, these results indicate that TP upregulates the expression of ZO-1 and decreases podocyte permeability through TET2-mediated 5 mC demethylation. These findings suggest that TP may alleviate podocyte permeability through TET2-mediated hydroxymethylation of ZO-1.

Effects of Natural Products through Inhibiting Endoplasmic Reticulum Stress on Attenuation of Idiopathic Pulmonary Fibrosis

With ever-increasing intensive studies of idiopathic pulmonary fibrosis (IPF), significant progresses have been made. Endoplasmic reticulum stress (ERS)/unfolded protein reaction (UPR) is associated with the development and progression of IPF, and targeting ERS/UPR may be beneficial in the treatment of IPF. Natural product is a tremendous source of new drug discovery, and accumulating studies have reported that many natural products show potential therapeutic effects for IPF via modulating one or more branches of the ERS signaling pathway. Therefore, this review focuses on critical roles of ERS in IPF development, and summarizes herbal preparations and bioactive compounds which protect against IPF through regulating ERS.

Reversible Contraception in Males: An Obtainable Target?

The last few decades have brought contraception to the forefront of research, with great strides made in effectively targeting and optimizing the physiology, pharmacology, and delivery processes that prevent pregnancy. However, these advances still predominantly target female contraceptives for the prevention of contraception, whereas targeting the male sex has lagged far behind. This has led to a marked deficiency in safe and effective male contraceptive agents, resulting in a heavy dependence on female contraceptives to prevent unwanted and unplanned pregnancies. Current research in the veterinary field and in rodents highlights several promising avenues whereby novel, safe, and effective male contraceptive alternatives are being developed-with an emphasis on reduced side effects and reversibility potential. This review aims to discuss current and novel male contraceptives (both human and veterinary formulations) while highlighting their efficacy, advantages, and disadvantages.

Tripterygium wilfordii Hook.f induced kidney injury through mediating inflammation via PI3K-Akt/HIF-1/TNF signaling pathway: A study of network toxicology and molecular docking

We intend to explore potential mechanisms of Tripterygium wilfordii Hook.f (TwHF) induced kidney injury (KI) using the methods of network toxicology and molecular docking. We determined TwHF potential compounds with its targets and KI targets, obtained the TwHF induced KI targets after intersecting targets of TwHF and KI. Then we conducted protein-protein interaction (PPI) network, gene expression analysis, gene ontology (GO) function and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis to explore the mechanism of TwHF-induced KI. Finally we conducted molecular docking to verify the core toxic compounds and the targets. We obtained 12 TwHF toxic compounds and 62 TwHF-induced KI targets. PPI network, gene expression analysis and GO function enrichment analysis unveiled the key biological process and suggested the mechanism of TwHF-induced KI might be associated with inflammation, immune response, hypoxia as well as oxidative stress. KEGG pathway enrichment analysis indicated PI3K-Akt signaling pathway, HIF-1 signaling pathway and TNF signaling pathway were key signaling pathways of TwHF induced KI. Molecular docking showed that the binding energy of core targets and toxic compounds was all less than -6.5 kcal/mol that verified the screening ability of network pharmacology and provided evidence for modifying TwHF toxic compounds structure. Through the study, we unveiled the mechanism of TwHF induce KI that TwHF might activate PI3K-Akt signaling pathway as well as TNF signaling pathway to progress renal inflammation, mediate hypoxia via HIF-1 signaling pathway to accelerate inflammatory processes, and also provided a theoretical basis for modifying TwHF toxic compounds structure as well as supported the follow-up research.

Subchronic toxicity evaluation of Huobahuagen extract and plasma metabolic profiling analysis combined with conventional pathology methods

Huobahua, namely, Tripterygium hypoglaucum (Levl.) Hutch, known as a traditional Chinese herbal medicine, especially its underground parts, has been widely developed into several Tripterygium agents for the treatment of rheumatoid arthritis and other autoimmune diseases. It has sparked wide public concern about its safety, such as multi-organ toxicity. However, the toxic characteristics and damage mechanism of Huobahuagen extract (HBHGE) remain unclear. In the present study, subchronic oral toxicity study of HBHGE (10.0 g crude drug/kg/day for 12 weeks) was performed in male rats. Hematological, serum biochemical, and histopathological parameters, urinalysis, and plasma metabolic profiling were assessed. The single-dose subchronic toxicity results related to HBHGE exhibited obvious toxicity to the testis and epididymis of male rats. Furthermore, plasma metabolomics analysis suggested that a series of metabolic disorders were induced by oral administration of HBHGE, mainly focusing on amino acid (glutamate, phenylalanine, and tryptophan) metabolisms, pyrimidine metabolism, glutathione metabolism, and steroid hormone biosynthesis. Moreover, it appeared that serum testosterone in male rats treated with HBHGE for 12 weeks, decreased significantly, and was susceptible to the toxic effects of HBHGE. Taken together, conventional pathology and plasma metabolomics for preliminarily exploring subchronic toxicity and underlying mechanism can provide useful information about the reduction of toxic risks from HBHGE and new insights into the development of detoxification preparations.

Celastrol, which targets IL-2/CD25 binding inhibition, induces T cell-mediated antitumor activity in melanoma

Interleukin-2 (IL-2) induces contrasting immune responses depending on its binding receptor subunit; thus, selective receptor binding is considered a key challenge in cancer therapeutic strategies. In this study, we aimed to investigate the inhibition of IL-2 action and antitumor activity of celastrol (CEL), a compound identified in a screen for IL-2/CD25 binding inhibitors, and to elucidate the underlying role of CEL in immune cells. We found that CEL selectively impairs the binding of IL-2 and CD25 and directly binds to IL-2 but not to CD25. CEL significantly suppressed the proliferation and signaling of IL-2-dependent murine T cells and interfered with IL-2-responsive STAT5 phosphorylation in IL-2 reporter cells and human PBMCs. After confirming the impact of CEL on IL-2, we evaluated its antitumor activity in C57BL/6 mice bearing B16F10 tumors and found that CEL significantly inhibited tumor growth by increasing CD8+ T cells. We also found that CEL did not inhibit tumor growth in T cell-deficient BALB/c nude mice, suggesting that its activity was mediated by the T-cell response. Moreover, combination therapy with low-dose CEL and a TNFR2 antagonist synergistically improved the therapeutic efficacy of the individual monotherapies by increasing the ratio of intratumoral CD8/Treg cells and suppressing Foxp3 expression. These findings suggest that CEL, which inhibits CD25 binding by targeting IL-2, exerts antitumor activity by mediating the T-cell response and could be a promising candidate for combination therapy in cancer immunotherapy against melanoma.

The NLRP3 Inflammasome as a Pathogenic Player Showing Therapeutic Potential in Rheumatoid Arthritis and Its Comorbidities: A Narrative Review

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterized by chronic synovitis and the progressive destruction of cartilage and bone. RA is commonly accompanied by extra-articular comorbidities. The pathogenesis of RA and its comorbidities is complex and not completely elucidated. The assembly of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activates caspase-1, which induces the maturation of interleukin (IL)-1β and IL-18 and leads to the cleavage of gasdermin D with promoting pyroptosis. Accumulative evidence indicates the pathogenic role of NLRP3 inflammasome signaling in RA and its comorbidities, including atherosclerotic cardiovascular disease, osteoporosis, and interstitial lung diseases. Although the available therapeutic agents are effective for RA treatment, their high cost and increased infection rate are causes for concern. Recent evidence revealed the components of the NLRP3 inflammasome as potential therapeutic targets in RA and its comorbidities. In this review, we searched the MEDLINE database using the PubMed interface and reviewed English-language literature on the NLRP3 inflammasome in RA and its comorbidities from 2000 to 2023. The current evidence reveals that the NLRP3 inflammasome contributes to the pathogenesis of RA and its comorbidities. Consequently, the components of the NLRP3 inflammasome signaling pathway represent promising therapeutic targets, and ongoing research might lead to the development of new, effective treatments for RA and its comorbidities.

Oral delivery of pH-sensitive nanoparticles loaded Celastrol targeting the inflammatory colons to treat ulcerative colitis

The incidence of ulcerative colitis (UC) is rapidly rising worldwide. Oral drug delivery system is a promising approach for treating UC, but it often fails to accumulate to the inflammatory lesions, thus, it is impressive to develop a colon-targeted oral delivery system for preventing systemic toxicity and maintaining UC therapeutics. Here, a negative-charged PLGA nanoparticle system was designed to encapsulate celastrol (Cel), and then chitosan and mannose were coated on the surface of the nanoparticles (MC@Cel-NPs) to endow these nanoparticles with the mucosal adsorption and macrophage targeting abilities. MC@Cel-NPs demonstrate excellent resist decomposition ability against the strong acidic gastrointestinal environment, and accumulates in the specific inflammatory sites through the affinity of electrostatic reaction. After releasing the payload, MC@Cel-NPs could remarkably alleviate the colon inflammation, which was evidenced by the decrease in pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 in both blood and colon sections, and scavenging reactive oxygen species (ROS) in colon cells, including macrophage, neutrophil, T cell, and B cell. This nanoparticle system provided a new approach for treating UC through a Chinese herbal ingredient-related oral delivery manner.

Celastrol induces premature ovarian insufficiency by inducing apoptosis in granulosa cells

Celastrol, a natural compound purified from the Chinese herb Tripterygium wilfordii Hook. f., has excellent pharmacological activity for the treatment of various diseases. Assessing the safety of its use is essential for its development into a clinical medicine. However, research assessing its toxicity on the female reproductive system has never been reported. In this study, the ovarian toxicity of celastrol and its underlying mechanism were investigated. We found that celastrol induced premature ovarian insufficiency and apoptosis in granulosa cells. Activity-based protein profiling results showed that high mobility group box 1 was a candidate target protein of celastrol. Celastrol directly bound to Cys106 of high mobility group box 1. Knocking down high mobility group box 1 induced apoptosis of granulosa cells, while overexpression of this gene reversed celastrol-induced apoptosis. Celastrol treatment upregulated p21 transcription, but overexpression of high mobility group box 1 reversed this upregulation. Thus, Celastrol induces premature ovarian insufficiency and apoptosis in granulosa cells by directly binding to high mobility group box 1 and interfering with its biological function to regulate p21 transcription. This study provides valuable information for assessing the safety of the clinical application of celastrol on female patients.

Mechanisms of action of natural products on type 2 diabetes

Over the past several decades, type 2 diabetes mellitus (T2DM) has been considered a global public health concern. Currently, various therapeutic modalities are available for T2DM management, including dietary modifications, moderate exercise, and use of hypoglycemic agents and lipid-lowering medications. Although the curative effect of most drugs on T2DM is significant, they also exert some adverse side effects. Biologically active substances found in natural medicines are important for T2DM treatment. Several recent studies have reported that active ingredients derived from traditional medicines or foods exert a therapeutic effect on T2DM. This review compiled important articles regarding the therapeutic effects of natural products and their active ingredients on islet β cell function, adipose tissue inflammation, and insulin resistance. Additionally, this review provided an in-depth understanding of the multiple regulatory effects on different targets and signaling pathways of natural medicines in the treatment of T2DM as well as a theoretical basis for clinical effective application.

Mechanistic engineering of celastrol liposomes induces ferroptosis and apoptosis by directly targeting VDAC2 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of most common and deadliest malignancies. Celastrol (Cel), a natural product derived from the Tripterygium wilfordii plant, has been extensively researched for its potential effectiveness in fighting cancer. However, its clinical application has been hindered by the unclear mechanism of action. Here, we used chemical proteomics to identify the direct targets of Cel and enhanced its targetability and anti-tumor capacity by developing a Cel-based liposomes in HCC. We demonstrated that Cel selectively targets the voltage-dependent anion channel 2 (VDAC2). Cel directly binds to the cysteine residues of VDAC2, and induces cytochrome C release via dysregulating VDAC2-mediated mitochondrial permeability transition pore (mPTP) function. We further found that Cel induces ROS-mediated ferroptosis and apoptosis in HCC cells. Moreover, coencapsulation of Cel into alkyl glucoside-modified liposomes (AGCL) improved its antitumor efficacy and minimized its side effects. AGCL has been shown to effectively suppress the proliferation of tumor cells. In a xenograft nude mice experiment, AGCL significantly inhibited tumor growth and promoted apoptosis. Our findings reveal that Cel directly targets VDAC2 to induce mitochondria-dependent cell death, while the Cel liposomes enhance its targetability and reduces side effects. Overall, Cel shows promise as a therapeutic agent for HCC.

Biotin decorated celastrol-loaded ZIF-8 nano-drug delivery system targeted epithelial ovarian cancer therapy

Ovarian cancer (OC) stands as the second most prominent factor leading to cancer-related fatalities, characterized by a notably low five-year survival rate. The insidious onset of OC combined with its resistance to chemotherapy poses significant challenges in terms of treatment, emphasizing the utmost importance of developing innovative therapeutic agents. Despite its remarkable anti-tumor efficacy, celastrol (CEL) faces challenges regarding its clinical utilization in OC due to its restricted water solubility and notable side effects. In this study, celastrol (CEL) was encapsulated into Zeolitic imidazolate framework-8(ZIF-8) nanoparticle and grafted with biotin-conjugated polyethylene glycol (CEL@ZIF-8@PEG-BIO). Comprehensive comparisons of the physicochemical properties and anticancer activities of CEL and CEL@ZIF-8@PEG-BIO were conducted. Our findings revealed that CEL@ZIF-8@PEG-BIO exhibited favorable characteristics, including hydrodynamic diameters of 234.5 nm, excellent water solubility, high drug loading (31.60% ± 2.85), encapsulation efficiency (60.52% ± 2.79), and minimal side effects. Furthermore, CEL@ZIF-8@PEG-BIO can release chemicals in response to an acidic micro-environment, which is more likely a tumor micro-environment. In vitro, studies showed that CEL@ZIF-8@BIO inhibited cell proliferation, led to mitochondrial membrane potential (MMP) decline, and generated reactive oxygen species in OC cells. Both in vitro and in vivo experiments indicated that CEL@ZIF-8@PEG-BIO enhanced anti-tumor activity against OC via up-regulated apoptosis-promoting biomarkers and rendered cancer cell apoptosis via the P38/JNK MAPK signaling pathway. In conclusion, we have successfully developed a novel drug delivery system (CEL@ZIF-8@PEG-BIO), resulting in significant improvements in both water solubility and anti-tumor efficacy thereby providing valuable insights for future clinical drug development.

Celastrol functions as an emerging manager of lipid metabolism: Mechanism and therapeutic potential

Lipid metabolism disorders are pivotal in the development of various lipid-related diseases, such as obesity, atherosclerosis, non-alcoholic fatty liver disease, type 2 diabetes, and cancer. Celastrol, a bioactive compound extracted from the Chinese herb Tripterygium wilfordii Hook F, has recently demonstrated potent lipid-regulating abilities and promising therapeutic effects for lipid-related diseases. There is substantial evidence indicating that celastrol can ameliorate lipid metabolism disorders by regulating lipid profiles and related metabolic processes, including lipid synthesis, catabolism, absorption, transport, and peroxidation. Even wild-type mice show augmented lipid metabolism after treatment with celastrol. This review aims to provide an overview of recent advancements in the lipid-regulating properties of celastrol, as well as to elucidate its underlying molecular mechanisms. Besides, potential strategies for targeted drug delivery and combination therapy are proposed to enhance the lipid-regulating effects of celastrol and avoid the limitations of its clinical application.