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Background: Prostate cancer (PCa) is a leading malignancy among men globally, with rising incidence rates emphasizing the critical need for better detection and therapeutic approaches. The roles of HSP90AB1 and PARP1 in prostate cancer cells suggest potential targets for enhancing treatment efficacy. Methods: This study investigated the overexpression of HSP90AB1 and PARP1 in prostate cancer cells and the impact of HSP90AB1 knockdown on the sensitivity of these cells to the PARP inhibitor olaparib. We also explored the combined effect of olaparib and celastrol, an HSP90 inhibitor, on the clonogenic survival, migration, proliferation, and overall viability of prostate cancer cells, alongside the modulation of the PI3K/AKT pathway. An in vivo PC3 xenograft mouse model was used to assess the antitumor effects of the combined treatment. Results: Our findings revealed significant overexpression of HSP90AB1 and PARP1 in prostate cancer cells. Knockdown of HSP90AB1 increased cell sensitivity to olaparib. The combination of olaparib and celastrol significantly reduced prostate cancer cell survival, migration, proliferation, and enhanced cumulative DNA damage. Celastrol also downregulated the PI3K/AKT pathway, increasing cell susceptibility to olaparib. In vivo experiments demonstrated that celastrol and olaparib together exerted strong antitumor effects. Conclusions: The study indicates that targeting both HSP90AB1 and PARP1 presents a promising therapeutic strategy for prostate cancer. The synergistic combination of celastrol and olaparib enhances the efficacy of treatment against prostate cancer, offering a potent approach to combat this disease. [ABSTRACT FROM AUTHOR]

Simple Summary: Standard chemotherapy is still ineffective in metastatic colon cancer and does not target cancer stem cells (CSCs). The combination of standard cytostatic drugs with natural compounds is considered a promising approach to improving cancer cell sensitivity to treatment. Here, a combination of camptothecin (CPT) with celastrol (CEL) or resveratrol (RSV) as a potential strategy to target metastatic and CSCs of colon cancer was investigated in vitro. γH2AX+ and Fast-Halo assays were used to evaluate genotoxicity, an annexin-V assay was used to rate the level of apoptosis, and a scratch test was used to assess antimigratory capacity. All combinations improved the genotoxicity of CPT, achieving a better efficacy with CPT-CEL combination in LOVO and CPT-RSV in LOVO/DX cells. No improvement in the pro-apoptotic effect of CPT was observed. Furthermore, higher efficiency in inhibiting cancer cell migration was noted. Background: Colorectal cancer is one of the leading and most lethal neoplasms. Standard chemotherapy is ineffective, especially in metastatic cancer, and does not target cancer stem cells. A promising approach to improve cancer treatment is the combination therapy of standard cytostatic drugs with natural compounds. Several plant-derived compounds have been proven to possess anticancer properties, including the induction of apoptosis and inhibition of cancer invasion. This study was focused on investigating in vitro the combination of camptothecin (CPT) with celastrol (CEL) or resveratrol (RSV) as a potential strategy to target metastatic (LOVO) and stem-like (LOVO/DX) colon cancer cells. Methods: The genotoxic effects that drive cancer cells into death-inducing pathways and the ability to inhibit the migratory properties of cancer cells were evaluated. The γH2AX+ assay and Fast-Halo Assay (FHA) were used to evaluate genotoxic effects, the annexin-V apoptosis assay to rate the level of apoptosis, and the scratch test to assess antimigratory capacity. Results: The results showed that both combinations CPT-CEL and CPT-RSV improve general genotoxicity of CPT alone on metastatic cells and CSCs. However, the assessment of specific double-stranded breaks (DSBs) indicated a better efficacy of the CPT-CEL combination on LOVO cells and CPT-RSV in LOVO/DX cells. Interestingly, the combinations CPT-CEL and CPT-RSV did not improve the pro-apoptotic effect of CPT alone, with both LOVO and LOVO/DX cells suggesting activation of different cell death mechanisms. Furthermore, it was found that the combinations of CPT-CEL and CPT-RSV improve the inhibitory effect of camptothecin on cell migration. Conclusions: These findings suggest the potential utility of combining camptothecin with celastrol or resveratrol in the treatment of colon cancer, including more aggressive forms of the disease. So far, no studies evaluating the effects of combinations of these compounds have been published in the available medical databases. [ABSTRACT FROM AUTHOR]

AbstractCelastrol (CEL) belongs to the group of non-steroidal immunosuppressants with the potential to improve cardiac hypertrophy (CH). However, the poor biocompatibility and low bioavailability of CEL limit its in vivo application. This study was aimed to develop a targeted drug delivery system that can efficiently and safely deliver CEL to target tissues, providing a research basis for the application of CEL in CH therapy. A novel ROS-sensitive drug-loaded nanomicelle, dodecanoic acid (DA)-phenylboronic acid pinacol ester-dextran polymer encapsulating CEL (DBD@CEL), was synthesized using chemical synthesis. Then, the morphology, particle size, drug-loaded content, and ROS-responsive release behavior of DBD@CEL were studied. Pharmacokinetics and biocompatibility were evaluated using healthy mice. Finally, the ability and mechanism of DBD@CEL in improving CH in vivo were investigated using a mouse CH model. DBD@CEL was successfully prepared with a drug loading of 18.9%. It exhibited excellent stability with an average particle size of 110.0 ± 1.7 nm. Within 48 h, DBD@CEL released only 19.4% in the absence of H2O2, while in the presence of 1 mM H2O2, the release rate increased to 71.5%. Biocompatibility studies indicated that DBD@CEL did not cause blood cell hemolysis, had no impact on normal organs, and did not result in abnormal blood biochemical indicators, demonstrating excellent biocompatibility. In vivo studies revealed that DBD@CEL regulated the activation of NF-κB signaling, inhibits pyroptosis and oxidative stress, and thereby ameliorates CH. The ROS-responsive DBD@CEL nanodrug delivery system enhances the therapeutic activity of CEL for CH, providing a promising drug delivery system for the clinical treatment of CH. [ABSTRACT FROM AUTHOR]

Considering that the precise delivery of Celastrol (Cst) into mitochondria to induce mitochondrial dysfunction may be a potential approach to improve the therapeutic outcomes of Cst on TNBC, a novel tumor mitochondria dual-targeted mixed-micelle nano-system was fabricated via self-synthesized triphenylphosphonium-modified cholesterol (TPP-Chol) and hyaluronic acid (HA)-modified cholesterol (HA-Chol). The Cst-loaded mixed micelles (Cst@HA/TPP-M) exhibited the characteristics of a small particle size, negative surface potential, high drug loading of up to 22.8%, and sustained drug release behavior. Compared to Cst-loaded micelles assembled only by TPP-Chol (Cst@TPP-M), Cst@HA/TPP-M decreased the hemolysis rate and upgraded the in vivo stability and safety. In addition, a series of cell experiments using the triple-negative breast cancer cell line MDA-MB-231 as a cell model proved that Cst@HA/TPP-M effectively increased the cellular uptake of the drug through CD44-receptors-mediated endocytosis, and the uptake amount was three times that of the free Cst group. The confocal results demonstrated successful endo-lysosomal escape and effective mitochondrial transport triggered by the charge converse of Cst@HA/TPP-M after HA degradation in endo-lysosomes. Compared to the free Cst group, Cst@HA/TPP-M significantly elevated the ROS levels, reduced the mitochondrial membrane potential, and promoted tumor cell apoptosis, showing a better induction effect on mitochondrial dysfunction. In vivo imaging and antitumor experiments based on MDA-MB-231-tumor-bearing nude mice showed that Cst@HA/TPP-M facilitated drug enrichment at the tumor site, attenuated drug systemic distribution, and polished up the antitumor efficacy of Cst compared with free Cst. In general, as a target drug delivery system, mixed micelles co-constructed by TPP-Chol and HA-Chol might provide a promising strategy to ameliorate the therapeutic outcomes of Cst on TNBC. [ABSTRACT FROM AUTHOR]

Pulmonary fibrosis (PF) is a horrible lung disease that causes pulmonary ventilation dysfunction and respiratory failure, severely impacting sufferers' physical and mental health. Existing drugs can only partially control the condition and are prone to toxic side effects. Anti-inflammatory treatment is the committed step to alleviate PF. Celastrol (CLT) has significant anti-inflammatory effects and can reverse M1-type transformation of macrophages. In this study, we have developed liposomes loaded with CLT, modified with folate (FA), designated FA-CLT-Lips, which facilitate drug delivery by targeting macrophages. FA-CLT-Lips were shown to be more readily absorbed by macrophages in vitro and to encourage the transition of M1 macrophages into M2 macrophages. In addition, FA-CLT-Lips can inhibit the phosphorylation of Smad2/3, effectively reducing the deposition of extracellular matrix (ECM) and the production of inflammatory factors. This showed that FA-CLT-Lips can ameliorate early lung fibrosis by lowering inflammation. In vivo studies have shown that FA-CLT-Lips accumulate in lung tissue to better attenuate lung injury and collagen deposition, with less toxicity compared to free CLT. In summary, FA receptor-targeting liposomes loaded with CLT provide a secure and reliable PF therapy. [ABSTRACT FROM AUTHOR]

Objective: Non-alcoholic fatty liver disease (NAFLD) is a prevalent chronic liver disease globally, characterized by the accumulation of lipids, oxidative stress, and mitochondrial dysfunction in the liver. Celastrus orbiculatus Thunb. (COT) and its active compound celastrol (CEL) have demonstrated antioxidant and antiinflammatory properties. Our prior research has shown the beneficial effects of COT in mitigating NAFLD induced by a high-fat diet (HFD) in guinea pigs by reducing hepatic lipid levels and inhibiting oxidative stress. This study further assessed the effects of COT on NAFLD and explored its underlying mitochondriarelated mechanisms. Methods: COT extract or CELwas administered as an intervention in C57BL/6Jmice fed a HFD or in HepG2 cells treated with sodium oleate. Oral glucose tolerance test, biochemical parameters including liver enzymes, blood lipid, and pro-inflammatory factors, and steatosis were evaluated. Meanwhile, mitochondrial ultrastructure and indicators related to oxidative stress were tested. Furthermore, regulators of mitochondrial function were measured using RT-qPCR and Western blot. Results: The findings demonstrated significant reductions in hepatic steatosis, oxidative stress, and inflammation associated with NAFLD in both experimental models following treatment with COT extract or CEL. Additionally, improvements were observed in mitochondrial structure, ATP content, and ATPase activity. This improvement can be attributed to the significant upregulation of mRNA and protein expression levels of key regulators including FGF21, AMPK, PGC-1α, PPARγ, andSIRT3. Conclusion: These findings suggest that COT may enhance mitochondrial function by activating the FGF21/AMPK/PGC-1α signaling pathway to mitigate NAFLD, which indicated that COT has the potential to target mitochondria and serve as a novel therapeutic option for NAFLD. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: To reveal effect of celastrol （Cel） on apoptosis of liver and kidney cells in preeclampsia （PE） rats and its protective effect. Methods: Fifty pregnant SD rats were randomly divided into 5 groups（ n=10）: Control group, PE group, PE+lowdose Cel group （PE+L-Cel）, PE+medium-dose Cel group （PE+M-Cel）, PE+high-dose Cel group （PE+H-Cel）, PE rat model was induced by injection of lipopolysaccharide through tail vein. Rats in PE+L-Cel group, PE+M-Cel group and PE+H-Cel group were intraperitoneally injected with 5, 10 and 20 mg（/kg·d） Cel daily from 14~20 day of pregnancy. Control group and PE group were injected with equal volume of normal saline. Systolic blood pressure （SBP） and urine albumin of rats in each group were measured after treatment. Cell apoptosis of liver and kidney tissues were detected by TUNEL staining. Bcl-2 and Caspase-9 expressions in liver and kidney tissues were detected by immunohistochemical staining. ELISA was used to detect serum IFN-γ, IL-4, IL-17 and IL-10 levels. Results: Compared with PE group, SBP and urine albumin levels of PE+L-Cel group, PE+M-Cel group and PE+H-Cel group were decreased （P<0.05）, cells apoptosis rates of liver and kidney tissues were decreased （P<0.05）, positive expression of Caspase-9 was significantly reduced, Bcl-2 level was significantly increased, serum IFN-γ and IL-17 levels were reduced （P<0.05）, while IL-4 and IL-10 levels were increased （P<0.05）. Conclusion: Cel can reduce symptoms of PE rats and inhibit liver and kidney cell apoptosis, which may play a therapeutic effect by correcting imbalance of Th1/Th2 and Th17/Treg cells in PE rats. [ABSTRACT FROM AUTHOR]

Abstract Background Prostate cancer (PCa) is a leading malignancy among men globally, with rising incidence rates emphasizing the critical need for better detection and therapeutic approaches. The roles of HSP90AB1 and PARP1 in prostate cancer cells suggest potential targets for enhancing treatment efficacy. Methods This study investigated the overexpression of HSP90AB1 and PARP1 in prostate cancer cells and the impact of HSP90AB1 knockdown on the sensitivity of these cells to the PARP inhibitor olaparib. We also explored the combined effect of olaparib and celastrol, an HSP90 inhibitor, on the clonogenic survival, migration, proliferation, and overall viability of prostate cancer cells, alongside the modulation of the PI3K/AKT pathway. An in vivo PC3 xenograft mouse model was used to assess the antitumor effects of the combined treatment. Results Our findings revealed significant overexpression of HSP90AB1 and PARP1 in prostate cancer cells. Knockdown of HSP90AB1 increased cell sensitivity to olaparib. The combination of olaparib and celastrol significantly reduced prostate cancer cell survival, migration, proliferation, and enhanced cumulative DNA damage. Celastrol also downregulated the PI3K/AKT pathway, increasing cell susceptibility to olaparib. In vivo experiments demonstrated that celastrol and olaparib together exerted strong antitumor effects. Conclusions The study indicates that targeting both HSP90AB1 and PARP1 presents a promising therapeutic strategy for prostate cancer. The synergistic combination of celastrol and olaparib enhances the efficacy of treatment against prostate cancer, offering a potent approach to combat this disease.

Xueya Xu,&ast; Weili Lu,&ast; Hua Zhang, Xiaoying Wang, Caixia Huang, Qiuping Huang, Wen Xu, Wei Xu Pharmacy College, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Xiaoying Wang; Wei Xu, Pharmacy College, Fujian University of Traditional Chinese Medicine, 1 Qiuyang Road, Fuzhou, 350122, People’s Republic of China, Email 2003032@fjtcm.edu.cn; 2000017@fjtcm.edu.cnBackground: 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. Keywords: ROS-responsive polymeric micelles, photodynamic therapy, hepatoma-targeting, celastrol, combination anti-hepatoma therapy

Background: Following recent research advancements, an increasing level of evidence had been published to indicate that celastrol exerted a therapeutic effect on a range of nervous system diseases. This study therefore aimed to investigate the potential involvement of celastrol on ferroptosis and the blood-brain barrier disruption in intracerebral haemorrhage. Methods: We established a rat intracerebral haemorrhage and adrenal pheochromocytoma cell (PC12) OxyHb models using an ACSL4 overexpression vector. Ferroptosis-related indices were assessed using corresponding assay kits, and immunofluorescence and flow cytometry were used to measure reactive oxygen species (ROS) levels. Additionally, quantitative PCR (qPCR) and western blot analyses were conducted to evaluate the expression of key proteins and elucidate the role of celastrol in intracerebral haemorrhage (ICH). Results: Celastrol significantly improved neurological function scores, blood-brain barrier integrity, and brain water content in rats with ICH. Moreover, subsequent analysis of ferroptosis-related markers, such as Fe2+, ROS, MDA, and SOD, suggested that celastrol exerted a protective effect against the oxidative damage induced by ferroptosis in ICH rats and cells. Furthermore, Western blotting indicated that celastrol attenuated ferroptosis by modulating the expression levels of key proteins, including acyl-CoA synthetase long-chain family member 4 (ACSL4), glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), and anti-transferrin receptor 1 (TFR1) both in vitro and in vivo. ACSL4 overexpression attenuated the neuroprotective effects of celastrol on ICH in vitro. Molecular docking analysis revealed that celastrol interacted with ACSL4 via the GLU107, GLN109, ASN111, and LYS357 binding sites. Conclusions: Celastrol exerted antioxidant properties and aids in neurological recovery after stroke by suppressing ACSL4 expression during ferroptosis. As such, this drug represented a promising pharmaceutical candidate for the treatment of ICH.

Background: Despite the availability of chemotherapy drugs such as 5-fluorouracil (5-FU), the treatment of some cancers such as gastric cancer remains challenging due to drug resistance and side effects. This study aimed to investigate the effect of celastrol in combination with the chemotherapy drug 5-FU on proliferation and induction of apoptosis in human gastric cancer cell lines (AGS and EPG85-257). Materials and Methods: In this in vitro study, AGS and EPG85-257 cells were treated with different concentrations of celastrol, 5-FU, and their combination. Cell proliferation was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The synergistic effect of 5-FU and celastrol was studied using Compusyn software. The DNA content at different phases of the cell cycle and apoptosis rate was measured using flow cytometry. Results: Co-treatment with low concentrations (10% inhibitory concentration (IC10)) of celastrol and 5-FU significantly reduced IC50 (p < 0.05) so that 48 h after treatment, IC50 was calculated at 3.77 and 6.9 μM for celastrol, 20.7 and 11.6 μM for 5-FU, and 5.03 and 4.57 μM for their combination for AGS and EPG85-257 cells, respectively. The mean percentage of apoptosis for AGS cells treated with celastrol, 5-FU, and their combination was obtained 23.9, 41.2, and 61.9, and for EPG85-257 cells 5.65, 46.9, and 55.7, respectively. In addition, the 5-FU and celastrol-5-FU combination induced cell cycle arrest in the synthesis phase. Conclusions: Although celastrol could decrease the concentration of 5-fluorouracil that sufficed to suppress gastric cancer cells, additional studies are required to arrive at conclusive evidence on the anticancer effects of celastrol. [ABSTRACT FROM AUTHOR]

Abstract Background The oral administration of drugs for treating ulcerative colitis (UC) is hindered by several factors, including inadequate gastrointestinal stability, insufficient accumulation in colonic lesions, and uncontrolled drug release. Methods A multiple sensitive nano-delivery system comprising β-cyclodextrin (CD) and 4-(hydroxymethyl)phenylboronic acid (PAPE) with enzyme/reactive oxygen species (ROS) sensitivity was developed to load celastrol (Cel) as a comprehensive treatment for UC. Results Owing to the positive charge in the site of inflamed colonic mucosa, the negatively charged nanomedicine (Cel/NPs) could efficiently accumulate. Expectedly, Cel/NPs showed excellent localization ability to colon in vitro and in vivo tests. The elevated concentration of ROS and intestinal enzymes in the colon microenvironment quickly break the CD, resulting in Cel release partially to rebalance microbiota and recover the intestinal barrier. The accompanying cellular internalization of residual Cel/NPs, along with the high concentration of cellular ROS to trigger Cel burst release, could decrease the expression of inflammatory cytokines, inhibit colonic cell apoptosis, promote the macrophage polarization, scavenge ROS, and regulate the TLR4/NF-κB signaling pathway, which certified that Cel/NPs possessed a notably anti-UC therapy outcome. Conclusions We provide a promising strategy for addressing UC symptoms via an enzyme/ROS-sensitive oral platform capable of releasing drugs on demand. Graphical Abstract

Banglan Cai,1,2,&ast; Manman Qi,2,3,&ast; Xue Zhang,1,2 Denghai Zhang1– 3 1School of Basic Medicine, Ningxia Medical University, Yinchuan, People’s Republic of China; 2Shanghai Health Commission Key Laboratory of Artificial Intelligence (AI)-Based Management of Inflammation and Chronic Diseases, Shanghai Pudong Gongli Hospital, Shanghai, People’s Republic of China; 3School of Medicine, Shanghai University, Shanghai, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Denghai Zhang; Xue Zhang, Shanghai Health Commission Key Laboratory of Artificial Intelligence (AI)-Based Management of Inflammation and Chronic Diseases, Shanghai Pudong Gongli Hospital, Shanghai, 200135, People’s Republic of China, Tel +86-18916173857 ; +86-13524805404, Email Denghai_zhang@163.com; 2021021020@nxmu.edu.cnBackground: As a traditional Chinese medicine monomer derived from Tripterygium wilfordii Hook.f. with potential anticancer activity, celastrol can induce ferroptosis in hepatic stellate cells and inhibit their activation to alleviate liver fibrosis. Activation of ferroptosis can effectively inhibit Hepatocellular carcinoma (HCC). Whether celastrol inhibits HCC by inducing ferroptosis remains to be studied.Purpose: To explore the potential targets of celastrol against HCC through ferroptosis based on network pharmacology and to verify the anticancer effect of celastrol on HepG2 cells.Methods: We collected celastrol targets, HCC, and ferroptosis-related genes through online databases, and got their intersection targets. Subsequently, we obtained a protein-protein interaction (PPI) network, and performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to gain key genes for further study. They were verified in vitro and were performed molecular docking. The changes in cell proliferation and ferroptosis characteristics of HepG2 cells after celastrol treatment were detected.Results: 31 core target genes were screened for PPI network and enrichment analysis. The most significantly related KEGG pathway was chemical carcinogenesis-reactive oxygen species. The mRNA and protein levels of GSTM1 were significantly decreased after celastrol treatment. Molecular docking demonstrated the interaction between celastrol and GSTM1. Ferroptosis was induced and cell proliferation was inhibited by celastrol in HCC cells.Conclusion: Celastrol induces ferroptosis in HCC via regulating GSTM1 expression and may serve as a novel therapeutic compound with clinical potential in HCC treatment. Keywords: network pharmacology, celastrol, hepatocellular carcinoma, ferroptosis, reactive oxygen species

Objective: To investigate the pyroptosis-inducing effects of celastrol on tumor cells and to explore the potential mechanisms involved, specifically focusing on the role of the caspase-3/gasdermin E (GSDME) signaling pathway and the impact of endoplasmic reticulum (ER) stress and autophagy. Methods: Necrostatin-1 (Nec-1), lactate dehydrogenase release (LDH) assay, and Hoechst/propidium iodide (PI) double staining were employed to validate the mode of cell death. Western blot was used to detect the cleavage of GSDME and the expression of light chain 3 (LC3) and BIP. Results: Celastrol induced cell swelling with large bubbles, which is consistent with the pyroptotic phenotype. Moreover, treatment with celastrol induced GSDME cleavage, indicating the activation of GSDME-mediated pyroptosis. GSDME knockout via CRISPR/Cas9 blocked the pyroptotic morphology of celastrol in HeLa cells. In addition, cleavage of GSDME was attenuated by a specific caspase-3 inhibitor in celastrol-treated cells, suggesting that GSDME activation was induced by caspase-3. Mechanistically, celastrol induced endoplasmic reticulum (ER) stress and autophagy in HeLa cells, and other ER stress inducers produced effects consistent with those of celastrol. Conclusion: These findings suggest that celastrol triggers caspase-3/GSDME-dependent pyroptosis via activation of ER stress, which may shed light on the potential antitumor clinical applications of celastrol.

Bo Wang,1,2 Jiquan Shen,2 Changjian Zhou,2 Xinggao Wang,2 Shuanghu Wang,3 Ruixing Hou1 1Department of Orthopaedics, Suzhou Ruihua Orthopedic Hospital Affiliated Suzhou Medical College of Soochow University, Suzhou, Jiangsu, 215000, People’s Republic of China; 2Department of Orthopaedics, the Sixth Affiliated Hospital of Wenzhou Medical University, the People’s Hospital of Lishui, Lishui, Zhejiang, 323000, People’s Republic of China; 3Central Laboratory of the Sixth Affiliated Hospital of Wenzhou Medical University, the People’s Hospital of Lishui, Lishui, Zhejiang, 323000, People’s Republic of ChinaCorrespondence: Shuanghu Wang, Central Laboratory of the Sixth Affiliated Hospital of Wenzhou Medical University, the People’s Hospital of Lishui, Lishui, Zhejiang, 323000, People’s Republic of China, Email wangshuanghu@lsu.edu.cn Ruixing Hou, Department of Orthopaedics, Suzhou Ruihua Orthopedic Hospital Affiliated Suzhou Medical College of Soochow University, Suzhou, Jiangsu, 215000, People’s Republic of China, Email hrx2020@suda.edu.cnBackground: Rheumatoid Arthritis (RA) involves prolonged inflammation of the synovium, damaging joints and causing stiffness and deformity. Celastrol (Cel), derived from the Chinese herbal medicine Tripterygium wilfordii Hook F, offers immunosuppressive effects for RA treatment but is limited by poor solubility and bioavailability.Purpose: In this study, long-circulating Cel-loaded liposomes (Cel-LPs) were used to increase the pharmacokinetics of Cel, thereby improving drug delivery and efficacy for the treatment of RA.Methods: Cel-LPs were prepared and administered orally and intravenously to compare the elimination half-life of drugs and bioavailability of Cel. Cel-LPs were prepared using the lipid thin-layer-hydration-extrusion method. Human rheumatoid arthritis synovial (MH7A) cells were used to investigate the compatibility of Cel-LPs. The pharmacokinetic studies were performed on male Sprague-Dawley (SD) rats.Results: The Cel-LPs had an average size of 72.20 ± 27.99 nm, a PDI of 0.267, a zeta potential of − 31.60 ± 6.81 mV, 78.77 ± 5.69% drug entrapment efficiency and sustained release (5.83 ± 0.42% drug loading). The cytotoxicity test showed that liposomes had excellent biocompatibility and the fluorescence microscope diagram indicated that liposome entrapment increased intracellular accumulation of Rhodamine B by MH7A cells. Furthermore, the results exhibited that Cel-LPs improved the pharmacokinetics of Cel by increasing the elimination half-life (t1/2) to 11.71 hr, mean residence time (MRT(0-∞)) to 7.98 hr and apparent volume of distribution (Vz/F) to 44.63 L/kg in rats, compared to the Cel solution.Conclusion: In this study, liposomes were demonstrated to be effective in optimizing the delivery of Cel, enabling the formulation of Cel-LPs with prolonged blood circulation and sustained release characteristics. This formulation enhanced the intravenous solubility and bioavailability of Cel, developing a foundation for its clinical application in RA and providing insights on poorly soluble drug management.Keywords: celastrol, rheumatoid arthritis, liposomes, oral and intravenous delivery, pharmacokinetic

Abnormal proliferation of aggressive fibroblast-like synoviocytes (FLS) and perpetuate synovial inflammation can inevitably accelerate the progression of rheumatoid arthritis (RA). Herein, a strategy of simultaneously promoting FLS apoptosis and inhibiting inflammation as mediated by macrophages is proposed to restore synovial homeostasis for effective RA therapy. A hyaluronic acid-based dissolvable microneedle (MN) is fabricated for transdermal delivery of dual human serum albumin (HSA)-contained biomimetic nanocomplexes to regulate RA FLS and macrophages. Upon skin insertion, dual nanocomplexes are released rapidly from the MN and accumulate in RA joint microenvironment through both passive and active targeting as mediated by HSA. Thioketal-crosslinked fluorinated polyethyleneimine 1.8 K (TKPF) was constructed to bind the plasmid encoding pro-apoptotic gene PUMA with HSA coating layer (TKPF/pPUMA@HSA, TPH). TPH nanocomplexes can upregulate PUMA through RA FLS transfection to trigger efficient apoptosis. Also, HSA nanocomplexes encapsulating the classic anti-inflammatory natural product celastrol (Cel@HSA, CH) can inhibit inflammation of macrophages through blocking NF-κB pathway activation. TPH/CH MN can deplete RA FLS and inhibit M1 macrophage activation, suppress synovial hyperplasia as well as reduce bone and cartilage erosion in a collagen-induced arthritis (CIA) mouse model, demonstrating a promising strategy for efficient RA treatment.

Abstract Objective Melanoma, with its high degree of malignancy, stands as one of the most dangerous skin cancers and remains the primary cause of death from skin cancer. With studies demonstrating the potential of traditional Chinese medicine to intervene and treat melanoma, we turned our attention to celastrol. Celastrol is a triterpene compound extracted from the traditional Chinese medicine derived from Tripterygium wilfordii. Previous studies have shown that celastrol exerts inhibitory effects on various malignant tumors, including melanoma. Hence, our goal was to clarify the impact of celastrol on cell viability, apoptosis, and cell cycle progression by elucidating its effects on the PI3K/AKT/mTOR pathway. Methods CCK-8 and wound healing assays were used to determine the effect of celastrol on the viability and migration of B16-F10 cells. Changes in cell apoptosis, cell cycle, reactive oxygen species (ROS), and mitochondrial membrane potential were detected by flow cytometry. PI3K/AKT/mTOR pathway proteins and HIF-α mRNA expression in B16-F10 cells were detected by western blotting and qPCR. Moreover, the addition of a PI3K activator demonstrated that celastrol could inhibit the function of B16-F10 cells via the PI3K/AKT/mTOR pathway. Results Celastrol inhibited the viability and migration of B16-F10 cells. Through the inhibition of the PI3K/AKT/mTOR pathway down-regulates the expression of HIF-α mRNA, thereby causing an increase of ROS in cells and a decrease in the mitochondrial membrane potential to promote cell apoptosis and cell cycle arrest. The inhibitory effect of celastrol on B16-F10 cells was further demonstrated by co-culturing with a PI3K activator. Conclusion Celastrol inhibits the function of B16-F10 cells by inhibiting the PI3K/AKT/mTOR cellular pathway and regulating the expression of downstream HIF-α mRNA.

Background: The oral administration of drugs for treating ulcerative colitis (UC) is hindered by several factors, including inadequate gastrointestinal stability, insufficient accumulation in colonic lesions, and uncontrolled drug release. Methods: A multiple sensitive nano-delivery system comprising β-cyclodextrin (CD) and 4-(hydroxymethyl)phenylboronic acid (PAPE) with enzyme/reactive oxygen species (ROS) sensitivity was developed to load celastrol (Cel) as a comprehensive treatment for UC. Results: Owing to the positive charge in the site of inflamed colonic mucosa, the negatively charged nanomedicine (Cel/NPs) could efficiently accumulate. Expectedly, Cel/NPs showed excellent localization ability to colon in vitro and in vivo tests. The elevated concentration of ROS and intestinal enzymes in the colon microenvironment quickly break the CD, resulting in Cel release partially to rebalance microbiota and recover the intestinal barrier. The accompanying cellular internalization of residual Cel/NPs, along with the high concentration of cellular ROS to trigger Cel burst release, could decrease the expression of inflammatory cytokines, inhibit colonic cell apoptosis, promote the macrophage polarization, scavenge ROS, and regulate the TLR4/NF-κB signaling pathway, which certified that Cel/NPs possessed a notably anti-UC therapy outcome. Conclusions: We provide a promising strategy for addressing UC symptoms via an enzyme/ROS-sensitive oral platform capable of releasing drugs on demand. [ABSTRACT FROM AUTHOR]

Small molecule can be utilized to restore the effectiveness of existing major classes of antibiotics against antibiotic‐resistant bacteria. In this study, it is demonstrated that celastrol, a natural compound, can modify the bacterial cell wall and subsequently render bacteria more suceptible to β‐lactam antibiotics. It is shown that celastrol leads to incomplete cell wall crosslinking by modulating levels of c‐di‐AMP, a secondary messenger, in methicillin‐resistant Staphylococcus aureus (MRSA). This mechanism enables celastrol to act as a potentiator, effectively rendering MRSA susceptible to a range of penicillins and cephalosporins. Restoration of in vivo susceptibility of MRSA to methicillin is also demonstrated using a sepsis animal model by co‐administering methicillin along with celastrol at a much lower amount than that of methicillin. The results suggest a novel approach for developing potentiators for major classes of antibiotics by exploring molecules that re‐program metabolic pathways to reverse β‐lactam‐resistant strains to susceptible strains. [ABSTRACT FROM AUTHOR]

Celastrol, a bioactive molecule extracted from the plant Tripterygium wilfordii Hook F., possesses anti‐inflammatory, anti‐obesity and anti‐tumour properties. Despite its efficacy in improving erythema and scaling in psoriatic mice, the specific therapeutic mechanism of celastrol in atopic dermatitis (AD) remains unknown. This study aims to examine the role and mechanism of celastrol in AD using TNF‐α‐stimulated HaCaT cells and DNCB‐induced Balb/c mice as in vitro and in vivo AD models, respectively. Celastrol was found to inhibit the increased epidermal thickness, reduce spleen and lymph node weights, attenuate inflammatory cell infiltration and mast cell degranulation and decrease thymic stromal lymphopoietin (TSLP) as well as various inflammatory factors (IL‐4, IL‐13, TNF‐α, IL‐5, IL‐31, IL‐33, IgE, TSLP, IL‐17, IL‐23, IL‐1β, CCL11 and CCL17) in AD mice. Additionally, celastrol inhibited Ezrin phosphorylation at Thr567, restored mitochondrial network structure, promoted translocation of Drp1 to the cytoplasm and reduced TNF‐α‐induced cellular reactive oxygen species (ROS), mitochondrial ROS (mtROS) and mitochondrial membrane potential (MMP) production. Interestingly, Mdivi‐1 (a mitochondrial fission inhibitor) and Ezrin‐specific siRNAs lowered inflammatory factor levels and restored mitochondrial reticular formation, as well as ROS, mtROS and MMP production. Co‐immunoprecipitation revealed that Ezrin interacted with Drp1. Knocking down Ezrin reduced mitochondrial fission protein Drp1 phosphorylation and Fis1 expression while increasing the expression of fusion proteins Mfn1 and Mfn2. The regulation of mitochondrial fission and fusion by Ezrin was confirmed. Overall, celastrol may alleviate AD by regulating Ezrin‐mediated mitochondrial fission and fusion, which may become a novel therapeutic reagent for alleviating AD. [ABSTRACT FROM AUTHOR]

Natural products, while valuable for drug discovery, encounter limitations like uncertainty in targets and toxicity. As an important active ingredient in traditional Chinese medicine, celastrol exhibits a wide range of biological activities, yet its mechanism remains unclear. In this study, they introduced an innovative "Degradation‐based protein profiling (DBPP)" strategy, which combined PROteolysis TArgeting Chimeras (PROTAC) technology with quantitative proteomics and Immunoprecipitation‐Mass Spectrometry (IP‐MS) techniques, to identify multiple targets of natural products using a toolbox of degraders. Taking celastrol as an example, they successfully identified its known targets, including inhibitor of nuclear factor kappa B kinase subunit beta (IKKβ), phosphatidylinositol‐4,5‐bisphosphate 3‐kinase catalytic subunit alpha (PI3Kα), and cellular inhibitor of PP2A (CIP2A), as well as potential new targets such as checkpoint kinase 1 (CHK1), O‐GlcNAcase (OGA), and DNA excision repair protein ERCC‐6‐like (ERCC6L). Furthermore, the first glycosidase degrader is developed in this work. Finally, by employing a mixed PROTAC toolbox in quantitative proteomics, they also achieved multi‐target identification of celastrol, significantly reducing costs while improving efficiency. Taken together, they believe that the DBPP strategy can complement existing target identification strategies, thereby facilitating the rapid advancement of the pharmaceutical field. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic autoimmune inflammation. Excessive proliferation and inadequate apoptosis of synovial macrophages are the crucial events of RA. Therefore, delivering therapeutic molecules to synovial macrophages specifically to tackle apoptotic insufficiency probably can be an efficient way to reduce joint inflammation and bone erosion. Based on the characteristics of dextran sulphate (DS) specifically binding scavenger receptor A (SR-A) on macrophage and celastrol (CLT) inducing apoptosis, we designed synovial macrophage-targeted nano-emulsions encapsulated with CLT (SR-CLTNEs) and explored their anti-RA effect. After intravenous injection, fluorescence-labelled SR-CLTNEs successfully targeted inflammatory joints and synovial macrophages in a mouse model of RA, with the macrophage targeting efficiency of SR-CLTNEs, CLTNEs and free DID was 20.53%, 13.93% and 9.8%, respectively. In vivo and in vitro studies showed that SR-CLTNEs effectively promoted the apoptosis of macrophages, reshaped the balance between apoptosis and proliferation, and ultimately treated RA in a high efficiency and low toxicity manner. Overall, our work demonstrates the efficacy of using SR-CLTNEs as a novel nanotherapeutic approach for RA therapy and the great translational potential of SR-CLTNEs. [ABSTRACT FROM AUTHOR]

Introduction: Celastrol (Cel) is a widely used main component of Chinese herbal medicine with strong anti-inflammatory, antiviral and antitumor activities. In the present study, we aimed to elucidate the cellular molecular protective mechanism of Cel against diabetes-induced inflammation and endothelial dysfunction. Methods: Type 2 diabetes (T2DM) was induced by db/db mice, and osmotic pumps containing Cel (100 µg/kg/day) were implanted intraperitoneally and were calibrated to release the drug for 28 days. In addition, human umbilical vein endothelial cells (HUVECs) were cultured in normal or high glucose and palmitic acid-containing (HG + PA) media in the presence or absence of Cel for 48 h. Results: Cel significantly ameliorated the hyperglycemia-induced abnormalities in nuclear factor (erythroid-derived 2)-like protein 2 (Nrf2) pathway activity and alleviated HG + PA-induced oxidative damage. However, the protective effect of Cel was almost completely abolished in HUVECs transfected with short hairpin (sh)RNA targeting Nrf2, but not by nonsense shRNA. Furthermore, HG + PA reduced the phosphorylation of AMP-activated protein kinase (AMPK), the autophagic degradation of p62/Kelch-like ECH-associated protein 1 (Keap1), and the nuclear localization of Nrf2. However, these catabolic pathways were inhibited by Cel treatment in HUVECs. In addition, compound C (AMPK inhibitors) and AAV9-sh-Nrf2 reduced Cel-induced Nrf2 activation and angiogenesis in db/db mice. Discussion: Taking these findings together, the endothelial protective effect of Cel in the presence of HG + PA may be at least in part attributed to its effects to reduce reactive oxygen species (ROS) and inflammation through p62/Keap1-mediated Nrf2 activation. [ABSTRACT FROM AUTHOR]

AIM: To investigate the molecular mechanism underlying ferroptosis induced by celastrol (Cel) in huamn pancreatic cancer cell line PANC-1. METHODS: The viability of PANC-1 cells was analyzed by MTT assay, and the effects of Cel on cell proliferation were analyzed using EdU and colony formation assays. Flow cytometry and fluorescence microscopy were used to assess and observe changes in lipid reactive oxygen species (ROS) levels, respectively, while the levels of malondialdehyde (MDA), glutathione (GSH) and Fe2+ were measured using specific kits. The protein expression of glutathione peroxidase 4 (GPX4) was evaluated by Western blot, and GPX4 ubiquitination was measured by immunoprecipitation. RESULTS: It was found that the viability, proliferation and colony formation in PANC-1 cells decreased gradually as the concentration of Cel increased. Addition of Cel alone to the cells reduced both cell rounding and viability, while treatment with ferrostatin-1 (Fer-1) alone or in combination with Cel had no effect on either cell morphology or viability. Fluorescence staining of lipid ROS with BODIPYTM 581/591 C11 followed by flow cytometry analysis showed significantly increased levels of green fluorescence indicative of oxidized lipid ROS, which were further increased after treatment of the cells with Cel. Treatment of the cells with both Cel and Fer-1 reduced the green fluorescence and lipid ROS levels. Treatment with Cel also increased the levels of MDA and Fe2+, relative to the controls, which reducing the levels of GSH, while addition of both Cel and Fer-1 to the cells restored the levels of MDA, Fe +, and GSH to those of the control group. CONCLUSION: Treatment with Cel reduces the proliferation of pancreatic cancer cells by inducing fer-roptosis through promoting the ubiquitination and degradation of GPX4 [ABSTRACT FROM AUTHOR]

In our previous study, two oleanane-type pentacyclic triterpenoids (oleanolic acid and maslinic acid) were reported to affect the N-glycosylation and intracellular trafficking of intercellular adhesion molecule-1 (ICAM-1). The present study was aimed at investigating the structure–activity relationship of 13 oleanane-type natural triterpenoids with respect to the nuclear factor κB (NF-κB) signaling pathway and the expression, intracellular trafficking, and N-glycosylation of the ICAM-1 protein in human lung adenocarcinoma A549 cells. Hederagenin, echinocystic acid, erythrodiol, and maslinic acid, which all possess two hydroxyl groups, decreased the viability of A549 cells. Celastrol and pristimerin, both of which possess an α,β-unsaturated carbonyl group, decreased cell viability but more strongly inhibited the interleukin-1α-induced NF-κB signaling pathway. Oleanolic acid, moronic acid, and glycyrrhetinic acid interfered with N-glycosylation without affecting the cell surface expression of the ICAM-1 protein. In contrast, α-boswellic acid and maslinic acid interfered with the N-glycosylation of the ICAM-1 protein, which resulted in the accumulation of high-mannose-type N-glycans. Among the oleanane-type triterpenoids tested, α-boswellic acid and maslinic acid uniquely interfered with the intracellular trafficking and N-glycosylation of glycoproteins. [ABSTRACT FROM AUTHOR]

Background: Glioblastoma is one of the most common primary intracranial tumors of the central nervous system in adults. Although chemotherapy is an important component of glioblastoma treatment, its effectiveness remains unsatisfactory. Due to multiple immunosuppressive mechanisms, glioblastoma immunotherapy has not been effective in treating many patients as a result of the clinical breakthroughs in the field. Therefore, the development of cancer immunotherapy relies on the understanding of how tumors interact with the immune system and the analysis of their molecular determinants. This study identified the key interactions between immune cells in the glioma microenvironment using RNA microarrays and single-cell sequencing. Methods: First, we screened differentially expressed genes in tumor and control samples from GSE29796 and GSE50161 datasets using GEO2R. All differentially expressed genes were used to perform enrichment analysis and construct protein-protein interaction topological analysis to analyze the interaction between proteins. Using single-cell RNA sequencing data from the GSE162631 database, we identified immune cell types within the glioblastoma microenvironment, and validated the hub gene expression in these cells. In addition, based on the GEPIA and TIMER databases, hub genes were investigated and compared with immune infiltration to determine differential expression. Finally, CellChat was used to visualize the gene expression distribution and cell-to-cell communication analysis of the proteins between different types of cells. Results: We found that monocytes/macrophages may communicate with each other in the tumor microenvironment through MIF-(CD74+CXCR4) and MIF-(CD74+CD44). In addition, our study indicated that celastrol has the ability to inhibit inflammatory factors expression by MIF/CD74 signaling pathway in U87 cells. Conclusion: This study improved the effectiveness of cancer immunotherapy strategies and developed new ideas for immunotherapy that can be applied to glioblastoma. [ABSTRACT FROM AUTHOR]

In this report, we discuss the synthesis of a compound obtained from the derivatization of the natural compound celastrol. This derivative is connected to PEG azide moiety through an amide linkage. The linkage was achieved through the activation of the carboxylic acid using HOBt/EDC. The compound was fully characterized by proton (1H), carbon-13 (13C), heteronuclear single quantum coherence (HSQC), correlation spectroscopy (1H-1H-COSY), and distortionless enhancement by polarization transfer (DEPT) NMR. Ultraviolet (UV), Fourier-transform infrared (FTIR), and high-resolution mass spectrometry (HRMS) were also adopted. Computational investigations were conducted to forecast the binding mode between the synthesized compound and sarco-endoplasmic reticulum (SR) Ca2+ transport ATPase (SERCA), a known target for the development of novel therapeutics for rheumatoid arthritis. Additionally, the drug-likeness of the synthesized compound was assessed by predicting its pharmacokinetic properties. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction contributes to the development of secondary brain injury (SBI) following intracerebral hemorrhage (ICH) and represents a promising therapeutic target. Celastrol, the primary active component of Tripterygium wilfordii, is a natural product that exhibits mitochondrial and neuronal protection in various cell types. This study aims to investigate the neuroprotective effects of celastrol against ICH‐induced SBI and explore its underlying mechanisms. Celastrol improves neurobehavioral and cognitive abilities in mice with autologous blood‐induced ICH, reduces neuronal death in vivo and in vitro, and promotes mitochondrial function recovery in neurons. Single‐cell nuclear sequencing reveals that the cyclic adenosine monophosphate (cAMP)/cAMP‐activated exchange protein‐1 (EPAC‐1) signaling pathways are impacted by celastrol. Celastrol binds to cNMP (a domain of EPAC‐1) to inhibit its interaction with voltage‐dependent anion‐selective channel protein 1 (VDAC1) and blocks the opening of mitochondrial permeability transition pores. After neuron‐specific knockout of EPAC1, the neuroprotective effects of celastrol are diminished. In summary, this study demonstrates that celastrol, through its interaction with EPAC‐1, ameliorates mitochondrial dysfunction in neurons, thus potentially improving SBI induced by ICH. These findings suggest that targeting EPAC‐1 with celastrol can be a promising therapeutic approach for treating ICH‐induced SBI. [ABSTRACT FROM AUTHOR]

Objective: Melanoma, with its high degree of malignancy, stands as one of the most dangerous skin cancers and remains the primary cause of death from skin cancer. With studies demonstrating the potential of traditional Chinese medicine to intervene and treat melanoma, we turned our attention to celastrol. Celastrol is a triterpene compound extracted from the traditional Chinese medicine derived from Tripterygium wilfordii. Previous studies have shown that celastrol exerts inhibitory effects on various malignant tumors, including melanoma. Hence, our goal was to clarify the impact of celastrol on cell viability, apoptosis, and cell cycle progression by elucidating its effects on the PI3K/AKT/mTOR pathway. Methods: CCK-8 and wound healing assays were used to determine the effect of celastrol on the viability and migration of B16-F10 cells. Changes in cell apoptosis, cell cycle, reactive oxygen species (ROS), and mitochondrial membrane potential were detected by flow cytometry. PI3K/AKT/mTOR pathway proteins and HIF-α mRNA expression in B16-F10 cells were detected by western blotting and qPCR. Moreover, the addition of a PI3K activator demonstrated that celastrol could inhibit the function of B16-F10 cells via the PI3K/AKT/mTOR pathway. Results: Celastrol inhibited the viability and migration of B16-F10 cells. Through the inhibition of the PI3K/AKT/mTOR pathway down-regulates the expression of HIF-α mRNA, thereby causing an increase of ROS in cells and a decrease in the mitochondrial membrane potential to promote cell apoptosis and cell cycle arrest. The inhibitory effect of celastrol on B16-F10 cells was further demonstrated by co-culturing with a PI3K activator. Conclusion: Celastrol inhibits the function of B16-F10 cells by inhibiting the PI3K/AKT/mTOR cellular pathway and regulating the expression of downstream HIF-α mRNA. [ABSTRACT FROM AUTHOR]

Corneal stromal fibrosis is a common cause of visual impairment resulting from corneal injury, inflammation and surgery. Therefore, there is an unmet need for inhibiting corneal stromal fibrosis. However, bioavailability of topical eye drops is very low due to the tear and corneal barriers. In situ delivery offers a unique alternative to improve efficacy and minimize systemic toxicity. Herein, a drug delivery platform based on thermoresponsive injectable hydrogel/nano-micelles composite with in situ drug-controlled release and long-acting features is developed to prevent corneal scarring and reduce corneal stromal fibrosis in lamellar keratoplasty. The in-situ gelation hydrogels enabled direct delivery of celastrol to the corneal stroma. In vivo evaluation with a rabbit anterior lamellar keratoplasty model showed that hydrogel/micelles platform could effectively inhibit corneal stromal fibrosis. This strategy achieves controlled and prolonged release of celastrol in the corneal stroma of rabbit. Following a single corneal interlamellar injection, celastrol effectively alleviated fibrosis via mTORC1 signal promoting autophagy and inhibiting TGF-β1/Smad2/3 signaling pathway. Overall, this strategy demonstrates promise for the clinical application of celastrol in preventing corneal scarring and reducing corneal stromal fibrosis post-lamellar keratoplasty, highlighting the potential benefits of targeted drug delivery systems in ocular therapeutics. Thermoresponsive injectable and transparent hydrogel deliver drug locally to treat corneal scars and various eye diseases. [Display omitted] • An injectable thermoresponsive-hydrogel-based drug delivery platform was fabricated. • The in-situ gelation platform delivered celastrol directly to corneal stroma with controlled and prolonged release. • The platform hampered corneal scars in lamellar keratoplasty. • Celastrol alleviates fibrosis via promoting autophagy and inhibiting TGF-β1 pathway. [ABSTRACT FROM AUTHOR]

Glioblastoma, a highly aggressive and lethal brain cancer, lacks effective treatment options and has a poor prognosis. In our study, we explored the potential anti-cancer effects of sodium butyrate (SB) and celastrol (CEL) in two glioblastoma cell lines. SB, a histone deacetylase inhibitor, and CEL, derived from the tripterygium wilfordii plant, act as mTOR and proteasome inhibitors. Both can cross the blood–brain barrier, and they exhibit chemo- and radiosensitive properties in various cancer models. GB cell lines LN-405 and T98G were treated with SB and CEL. Cell viability was assessed by MTT assay and IC50 values were obtained. Gene expression of DNA repair, apoptosis, and autophagy-related genes was analyzed by RT-PCR. Cell cycle distribution was determined using flow cytometry. Viability assays using MTT assay revealed IC50 values of 26 mM and 22.7 mM for SB and 6.77 μM, and 9.11 μM for CEL in LN-405 and T98G cells, respectively. Furthermore, we examined the expression levels of DNA repair genes (MGMT, MLH-1, MSH-2, MSH-6), apoptosis genes (caspase-3, caspase-8, caspase-9), and an autophagy gene (ATG-6) using real-time polymerase chain reaction. Additionally, flow cytometry analysis revealed alterations in cell cycle distribution following treatment with SB, CEL and their combination. These findings indicate that SB and CEL may act through multiple mechanisms, including DNA repair inhibition, apoptosis induction, and autophagy modulation, to exert their anti-cancer effects in glioblastoma cells. This is the first study providing novel insights into the potential therapeutic effects of SB and CEL in glioblastoma. [ABSTRACT FROM AUTHOR]

Celastrol (CSL), an active compound extracted from the root bark of Tripterygium wilfordii, has been studied for its outstanding efficacy in anti-cancer and cerebral neurology. We have obtained a series of derivatives with reduced toxicity through biotransformation. Here, 23391 proteins of homo sapiens from AlphaFold DB and Schrödinger's Glide were used for reverse docking with the basic scaffold of CSL to discover the pharmacological activity of its derivatives. Based on the drug target database, the targets selected for the study were the RORα and RORγ of the Retinoic Acid Related-Orphan Receptors family (RORs). The series of compounds were filtered through QikProp, docked for dynamics stimulation and molecular mechanics-generalized born surface area (MMGBSA) binding energy calculations. We also performed fluorescence polarization assay (FP assay), luciferase reporter gene assay, and the CCK8 assay. In summary, we performed reverse docking of CSLs to find its key targets RORα and RORγ to explain its anti-inflammatory and anti-tumor effects, found binding sites Gln19, Arg97, Arg100 for RORα-Ligand binding domain (LBD) and Gln25, Leu26, Arg103, Arg106 for RORγ-LBD, screened for the highest affinity derivatives. The luciferase reporter gene assay showed that 2 μM 18-OH-CSL and 28-OH-CSL had the strongest agonistic effect on RORα-LBD, while CSLs had the weak inhibitory effect on RORγ-LBD, and these compounds also demonstrated a good apoptotic effect on the KG-1a tumor cell. [ABSTRACT FROM AUTHOR]

Post-stroke depression (POSD) is a common difficulty and most predominant emotional syndrome after stroke often consequences in poor outcomes. In the present investigation, we have designed and studied the neurologically active celastrol/minocycline encapsulated with macrophages-derived exosomes functionalized PLGA nanoformulations (CMC-EXPL) to achieve enhanced anti-inflammatory behaviour and anti-depressant like activity in a Rat model of POSD. The animal model of POSD was established through stimulating process with chronic unpredictable mild stress (CUM) stimulations after procedure of middle cerebral artery occlusion (MCAO). Neuronal functions and Anti-inflammation behaviours were observed by histopathological (H&E) examination and Elisa analyses, respectively. The anti-depressive activity of the nanoformulations treated Rat models were evaluated by open-field and sucrose preference test methods. Microglial polarization was evaluated via flow-cytometry and qRT-PCR observations. The observed results exhibited that prepared nanoformulations reduced the POSD-stimulated depressive-like activities in rat models as well alleviated the neuronal damages and inflammatory responses in the cerebral hippocampus. Importantly, prepared CMC-EXPL nanoformulation effectively prevented the M1 pro-inflammatory polarization and indorsed M2 anti-inflammatory polarization, which indicates iNOS and CD86 levels significantly decreased and upsurged Arg-1 and CD206 levels. CMC-EXPL nanoformulation suggestively augmented anti-depressive activities and functional capability and also alleviated brain inflammation in POSD rats, demonstrating its therapeutic potential for POSD therapy.

Celastrol, the primary constituent of Tripterygium wilfordii, has demonstrated neuroprotective properties in rats with dementia by reducing inflammation. A high-fat diet and streptozotocin injection were utilized to establish a diabetic rat model, which was then employed to investigate the possible protective effect of celastrol against the development of diabetes-induced learning and memory deficits. Afterwards, the experimental animals received a dose of celastrol by gavage (4 mg/kg/d). An animal study showed that celastrol enhanced insulin sensitivity and glucose tolerance in diabetic rats. In the Morris water maze test, rats with diabetes performed poorly in terms of spatial learning and memory; treatment with celastrol improved these outcomes. Additionally, administration of celastrol downregulated the expression of inflammatory-related proteins (NF-κB, IKKα, TNF-α, IL-1β, and IL-6) and greatly reduced the generation of Aβ in the diabetic hippocampus tissue. Moreover, the insulin signaling pathway-related proteins PI3K, AKT, and GSK-3β were significantly upregulated in diabetic rats after celastrol was administered. Also, celastrol prevented damage to the brain structures and increased the synthesis of synaptic proteins like PSD-95 and SYT1. In conclusion, celastrol exerts a neuroprotective effect by modulating the insulin signaling system and reducing inflammatory responses, which helps to ameliorate the cognitive impairment associated with diabetes.

Objectives: Celastrol has widespread therapeutic applications in various pathological conditions, including chronic inflammation. Previous studies have demonstrated the potent cardioprotective effects of celastrol. Nevertheless, limited attention has been given to its potential in reducing ventricular arrhythmias (VAs) following myocardial infarction (MI). Hence, this study aimed to elucidate the potential mechanisms underlying the regulatory effects of celastrol on VAs and cardiac electrophysiological parameters in rats after MI. Methods: Sprague-Dawley rats were divided at random: the sham, MI, and MI + celastrol groups. The left coronary artery was occluded in the MI and MI + Cel groups. Electrocardiogram, heart rate variability (HRV), ventricular electrophysiological parameters analysis, histology staining of ventricles, Enzyme-linked immunosorbent assay (ELISA), western blotting and Quantitative real-time polymerase chain reaction (qRT-PCR) were performed to elucidate the underlying mechanism of celastrol. Besides, H9c2 cells were subjected to hypoxic conditions to create an in vitro model of MI and then treated with celastrol for 24 hours. Nigericin was used to activate the NLRP3 inflammasome. Results: Compared with that MI group, cardiac electrophysiology instability was significantly alleviated in the MI + celastrol group. Additionally, celastrol improved HRV, upregulated the levels of Cx43, Kv.4.2, Kv4.3 and Cav1.2, mitigated myocardial fibrosis, and inhibited the NLRP3 inflammasome pathway. In vitro conditions also supported the regulatory effects of celastrol on the NLRP3 inflammasome pathway. Conclusions: Celastrol could alleviate the adverse effects of VAs after MI partially by promoting autonomic nerve remodeling, ventricular electrical reconstruction and ion channel remodeling, and alleviating ventricular fibrosis and inflammatory responses partly by through inhibiting the NLRP3/Caspase-1/IL-1β pathway.

Protein misfolding and aggregation are crucial pathogenic factors for cataracts, which are the leading cause of visual impairment worldwide. α-crystallin, as a small molecular chaperone, is involved in preventing protein misfolding and maintaining lens transparency. The chaperone activity of α-crystallin depends on its oligomeric state. Our previous work identified a natural compound, celastrol, which could regulate the oligomeric state of αB-crystallin. In this work, based on the UNcle and SEC analysis, we found that celastrol induced αB-crystallin to form large oligomers. Large oligomer formation enhanced the chaperone activity of αB-crystallin and prevented aggregation of the cataract-causing mutant βA3-G91del. The interactions between αB-crystallin and celastrol were detected by the FRET (Fluorescence Resonance Energy Transfer) technique, and verified by molecular docking. At least 9 binding patterns were recognized, and some binding sites covered the groove structure of αB-crystallin. Interestingly, αB-R120G, a cataract-causing mutation located at the groove structure, and celastrol can decrease the aggregates of αB-R120G. Overall, our results suggested celastrol not only promoted the formation of large αB-crystallin oligomers, which enhanced its chaperone activity, but also bound to the groove structure of its α-crystallin domain to maintain its structural stability. Celastrol might serve as a chemical and pharmacological chaperone for cataract treatment.

Abstract Background Malaria remains a global health burden, and the emergence and increasing spread of drug resistance to current antimalarials poses a major challenge to malaria control. There is an urgent need to find new drugs or strategies to alleviate this predicament. Celastrol (Cel) is an extensively studied natural bioactive compound that has shown potentially promising antimalarial activity, but its antimalarial mechanism remains largely elusive. Methods We first established the Plasmodium berghei ANKA-infected C57BL/6 mouse model and systematically evaluated the antimalarial effects of Cel in conjunction with in vitro culture of Plasmodium falciparum. The potential antimalarial targets of Cel were then identified using a Cel activity probe based on the activity-based protein profiling (ABPP) technology. Subsequently, the antimalarial mechanism was analyzed by integrating with proteomics and transcriptomics. The binding of Cel to the identified key target proteins was verified by a series of biochemical experiments and functional assays. Results The results of the pharmacodynamic assay showed that Cel has favorable antimalarial activity both in vivo and in vitro. The ABPP-based target profiling showed that Cel can bind to a number of proteins in the parasite. Among the 31 identified potential target proteins of Cel, PfSpdsyn and PfEGF1-α were verified to be two critical target proteins, suggesting the role of Cel in interfering with the de novo synthesis of spermidine and proteins of the parasite, thus exerting its antimalarial effects. Conclusions In conclusion, this study reports for the first time the potential antimalarial targets and mechanism of action of Cel using the ABPP strategy. Our work not only support the expansion of Cel as a potential antimalarial agent or adjuvant, but also establishes the necessary theoretical basis for the development of potential antimalarial drugs with pentacyclic triterpenoid structures, as represented by Cel. Video Abstract

Multiwalled carbon nanotubes (MWCNTs) have numerous applications in the field of carbon nanomaterials. However, the associated toxicity concerns have increased significantly because of their widespread use. The inhalation of MWCNTs can lead to nanoparticle deposition in the lung tissue, causing inflammation and health risks. In this study, celastrol, a natural plant medicine with potent anti-inflammatory properties, effectively reduced the number of inflammatory cells, including white blood cells, neutrophils, and lymphocytes, and levels of inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, in mice lungs exposed to MWCNTs. Moreover, celastrol inhibited the activation of the NF-κB-signaling pathway. This study confirmed these findings by demonstrating comparable reductions in inflammation upon exposure to MWCNTs in mice with the deletion of NF-κB (P50−/−). These results indicate the utility of celastrol as a promising pharmacological agent for preventing MWCNT-induced lung tissue inflammation. [ABSTRACT FROM AUTHOR]

Celastrol (Cel) shows potent antitumor activity in various experimental models. This study examined the relationship between Cel's antivascular and antitumor effects and sphingolipids. CCK-8 assay, transwell assay, Matrigel, PCR-array/RT-PCR/western blotting/immunohistochemistry assay, ELISA and HE staining were used to detect cell proliferation, migration and invasion, adhesion and angiogenesis, mRNA and protein expression, S1P production and tumor morphology. The results showed that Cel could inhibit proliferation, migration or invasion, adhesion and angiogenesis of human umbilical vein endothelial cells (HUVECs) and MDA-MB-231 cells by downregulating the expression of degenerative spermatocyte homolog 1 (DEGS1). Transfection experiments showed that downregulation of DEGS1 inhibited the above processes and sphingosine-1-phosphate (S1P) production of HUVECs and MDA-MB-231 cells, while upregulation of DEGS1 had the opposite effects. Coculture experiments showed that HUVECs could promote proliferation, migration and invasion of MDA-MB-231 cells through S1P/sphingosine-1-phosphate receptor (S1PR) signaling pathway, while Cel inhibited these processes in MDA-MB-231 cells induced by HUVECs. Animal experiments showed that Cel could inhibit tumor growth in nude mice. Western blotting, immunohistochemistry and ELISA assay showed that Cel downregulated the expression of DEGS1, CD146, S1PR1-3 and S1P production. These data confirm that DEGS1/S1P signaling pathway may be related to the antivascular and antitumor effects of cel. [ABSTRACT FROM AUTHOR]

Objective: To investigate the mechanistic basis for the anti-proliferation and anti-invasion effect of tumor necrosis factor-related apoptosis-induced ligand (TRAIL) and celastrol combination treatment (TCCT) in glioblastoma cells. Methods: Cell counting kit-8 was used to detect the effects of different concentrations of celastrol (0–16 µmol/L) and TRAIL (0–500 ng/mL) on the cell viability of glioblastoma cells. U87 cells were randomly divided into 4 groups, namely control, TRAIL (TRAIL 100 ng/mL), Cel (celastrol 0.5 µmol/L) and TCCT (TRAIL 100 ng/mL+ celastrol 0.5 µmol/L). Cell proliferation, migration, and invasion were detected by colony formation, wound healing, and Transwell assays, respectively. Quantitative reverse transcription polymerase chain reaction and Western blotting were performed to assess the levels of epithelial-mesenchymal transition (EMT) markers (zona occludens, N-cadherin, vimentin, zinc finger E-box-binding homeobox, Slug, and β-catenin). Wnt pathway was activated by lithium chloride (LiCl, 20 mol/L) and the mechanism for action of TCCT was explored. Results: Celastrol and TRAIL synergistically inhibited the proliferation, migration, invasion, and EMT of U87 cells (P<0.01). TCCT up-regulated the expression of GSK-3β and down-regulated the expression of β-catenin and its associated proteins (P<0.05 or P<0.01), including c-Myc, Cyclin-D1, and matrix metalloproteinase (MMP)-2. In addition, LiCl, an activator of the Wnt signaling pathway, restored the inhibitory effects of TCCT on the expression of β-catenin and its downstream genes, as well as the migration and invasion of glioblastoma cells (P<0.05 or P<0.01). Conclusions: Celastrol and TRAIL can synergistically suppress glioblastoma cell migration, invasion, and EMT, potentially through inhibition of Wnt/β-catenin pathway. This underlies a novel mechanism of action for TCCT as an effective therapy for glioblastoma. [ABSTRACT FROM AUTHOR]

Tripterygium wilfordii Hook F (TwHF) has a long history of use as a traditional Chinese medicine and has been widely administered to treat various inflammatory and autoimmune diseases. MicroRNAs (miRNAs) are endogenous, short, non-coding RNAs that regulate gene expression post-transcriptionally. They participate in the efficacies and even toxicities of the components of TwHF, rendering miRNAs an appealing therapeutic strategy. This review summarizes the recent literature related to the roles and mechanisms of miRNAs in the pharmacological and toxicological effects of main components of TwHF, focusing on two active compounds, triptolide (TP) and celastrol (CEL). Additionally, the prospects for the "You Gu Wu Yun" theory regarding TwHF nephrotoxicity are presented. [ABSTRACT FROM AUTHOR]

Protein misfolding and aggregation are crucial pathogenic factors for cataracts, which are the leading cause of visual impairment worldwide. 𝛼-crystallin, as a small molecular chaperone, is involved in preventing protein misfolding and maintaining lens transparency. The chaperone activity of 𝛼-crystallin depends on its oligomeric state. Our previous work identified a natural compound, celastrol, which could regulate the oligomeric state of 𝛼B-crystallin. In this work, based on the UNcle and SEC analysis, we found that celastrol induced 𝛼B-crystallin to form large oligomers. Large oligomer formation enhanced the chaperone activity of 𝛼B-crystallin and prevented aggregation of the cataract-causing mutant 𝛽A3-G91del. The interactions between 𝛼B-crystallin and celastrol were detected by the FRET (Fluorescence Resonance Energy Transfer) technique, and verified by molecular docking. At least 9 binding patterns were recognized, and some binding sites covered the groove structure of 𝛼B-crystallin. Interestingly, 𝛼B-R120G, a cataract-causing mutation located at the groove structure, and celastrol can decrease the aggregates of 𝛼B-R120G. Overall, our results suggested celastrol not only promoted the formation of large 𝛼B-crystallin oligomers, which enhanced its chaperone activity, but also bound to the groove structure of its 𝛼-crystallin domain to maintain its structural stability. Celastrol might serve as a chemical and pharmacological chaperone for cataract treatment. [ABSTRACT FROM AUTHOR]

Celastrol is a quinone methyl triterpenoid monomeric ingredient extracted from the root of Tripterygium wilfordii. Celastrol shows potential pharmacological activities in various diseases, which include inflammatory, obesity, cancer, and bacterial diseases. However, the application prospect of celastrol is largely limited by its low bioavailability, poor water solubility, and undesired off-target cytotoxicity. To address these problems, a number of drug delivery methods and technologies have been reported to enhance the efficiency and reduce the toxicity of celastrol. We classified the current drug delivery technologies into two parts. The direct chemical modification includes nucleic acid aptamer–celastrol conjugate, nucleic acid aptamer–dendrimer–celastrol conjugate, and glucolipid–celastrol conjugate. The indirect modification includes dendrimers, polymers, albumins, and vesicular carriers. The current technologies can covalently bond or encapsulate celastrol, which improves its selectivity. Here, we present a review that focalizes the recent advances of drug delivery strategies in enhancing the efficiency and reducing the toxicity of celastrol. [ABSTRACT FROM AUTHOR]

Background: Malaria remains a global health burden, and the emergence and increasing spread of drug resistance to current antimalarials poses a major challenge to malaria control. There is an urgent need to find new drugs or strategies to alleviate this predicament. Celastrol (Cel) is an extensively studied natural bioactive compound that has shown potentially promising antimalarial activity, but its antimalarial mechanism remains largely elusive. Methods: We first established the Plasmodium berghei ANKA-infected C57BL/6 mouse model and systematically evaluated the antimalarial effects of Cel in conjunction with in vitro culture of Plasmodium falciparum. The potential antimalarial targets of Cel were then identified using a Cel activity probe based on the activity-based protein profiling (ABPP) technology. Subsequently, the antimalarial mechanism was analyzed by integrating with proteomics and transcriptomics. The binding of Cel to the identified key target proteins was verified by a series of biochemical experiments and functional assays. Results: The results of the pharmacodynamic assay showed that Cel has favorable antimalarial activity both in vivo and in vitro. The ABPP-based target profiling showed that Cel can bind to a number of proteins in the parasite. Among the 31 identified potential target proteins of Cel, PfSpdsyn and PfEGF1-α were verified to be two critical target proteins, suggesting the role of Cel in interfering with the de novo synthesis of spermidine and proteins of the parasite, thus exerting its antimalarial effects. Conclusions: In conclusion, this study reports for the first time the potential antimalarial targets and mechanism of action of Cel using the ABPP strategy. Our work not only support the expansion of Cel as a potential antimalarial agent or adjuvant, but also establishes the necessary theoretical basis for the development of potential antimalarial drugs with pentacyclic triterpenoid structures, as represented by Cel. 5LH6oqsCtKBdVDis1L_PeK Video Abstract [ABSTRACT FROM AUTHOR]

Excessive oxidative stress impairs cartilage matrix metabolism balance, significantly contributing to osteoarthritis (OA) development. Celastrol (CSL), a drug derived from Tripterygium wilfordii , has recognized applications in the treatment of cancer and immune system disorders, yet its antioxidative stress mechanisms in OA remain underexplored. This study aimed to substantiate CSL's chondroprotective effects and unravel its underlying mechanisms. We investigated CSL's impact on chondrocytes under both normal and inflammatory conditions. In vitro , CSL mitigated interleukin (IL)-1β-induced activation of proteinases and promoted cartilage extracellular matrix (ECM) synthesis. In vivo , intra-articular injection of CSL ameliorated cartilage degeneration and mitigated subchondral bone lesions in OA mice. Mechanistically, it was found that inhibiting nuclear factor erythroid 2-related factor 2 (NRF2) abrogated CSL-mediated antioxidative functions and exacerbated the progression of OA. This study is the first to elucidate the role of CSL in the treatment of OA through the activation of NRF2, offering a novel therapeutic avenue for arthritis therapy. [ABSTRACT FROM AUTHOR]

In this work, pH/GSH-responsive amphiphilic polymeric prodrug (EDA-GLA/CE/2-FPBA) was successfully prepared and could self-assembled into micelles in an aqueous solution. The EDA-GLA/CE/2-FPBA micelles possessed high stability in physiological condition and were pH and GSH sensitive due to the reversible borate ester bonds and disulfide bonds within the prodrug polymer. The structures of the prodrug polymers were characterized by NMR, FTIR, UV–vis spectroscopy. Transmission electron microscopy and dynamic light scattering measurement indicated that the resulting micelles have desirable size distribution and regular spherical shape. Free active Celastrol can be released under low pH and high GSH environment; In vitro cellular uptake and growth inhibition assays suggested that the blank polymer micelles showed good biocompatibility. EDA-GLA/CE/2-FPBA micelles were more efficiently internalized by monolayer tumor cells and demonstrated superior tumor targeting effects as compared to free Celastrol control. These results demonstrated that the novel prodrug self-assembled dual-responsive nano-delivery platform was able to improve the bioavailability and tumor targeting activity of Celastrol, which provides a basis for further clinical applications of Celastrol and its derivatives. Amphiphilic polymeric prodrug (EDA-GLA/CE/2-FPBA) containing gelatin, lipoic acid, ethylenediamine (EDA), 2-formylphenylboric acid (2-FPBA) was developed, which can self-assembled into micelles in an aqueous solution. Borate ester bond and sulfhydryl groups in the micelles endow the micelles with the ability to respond to high concentration of GSH. [ABSTRACT FROM AUTHOR]

Celastrol (CST) has positive pharmacological effects on various cancers, but clinical application is limited because of poor water solubility and systemic toxicity. Ferric oxide (Fe3O4) has a large specific surface area and can be functionalized by inorganic modification to form complex magnetic drug delivery systems. Herein, Fe3O4 was surface-modified with citric acid and polyethylene glycol (PEG) (via) the Mitsunobu reaction and then covalently bound to CST. Finally, magnetic microbubbles (MMBs) containing perfluoropropane (C3F8) and Fe3O4-PEG2K-CST particles were constructed with poly(lactic-co-glycolic acid) (PLGA) as the shell membrane. In vitro studies showed that ultrasound-mediated MMBs exhibited improved inhibition of VX2 cell proliferation compared to inhibition achieved using MMBs without ultrasound mediation, blank MMBs, or free CST. In ultrasound mode, MMBs have favorable imaging properties. After the application of a high mechanical index, MMBs collapse through the cavitation effect, releasing their internal Fe3O4-PEG2K-CST. The CST is then delivered to the tumor microenvironment under acidic conditions. In magnetic resonance imaging T2 mode, a specific hypointense signal was observed in the tumor area compared with that before treatment, whereas no significant change occurred in the signal intensity of the surrounding organs. After treatment, pathological examination of tumor-bearing rabbit tissues showed that iron elements accumulated in several apoptosis cells in the tumor area, with no apparent abnormalities found in other areas. Thus, ultrasound-mediated MMBs could significantly improve the drug uptake of solid tumors and inhibit tumor growth with favorable biological safety. [ABSTRACT FROM AUTHOR]

Abstract Small molecule can be utilized to restore the effectiveness of existing major classes of antibiotics against antibiotic‐resistant bacteria. In this study, it is demonstrated that celastrol, a natural compound, can modify the bacterial cell wall and subsequently render bacteria more suceptible to β‐lactam antibiotics. It is shown that celastrol leads to incomplete cell wall crosslinking by modulating levels of c‐di‐AMP, a secondary messenger, in methicillin‐resistant Staphylococcus aureus (MRSA). This mechanism enables celastrol to act as a potentiator, effectively rendering MRSA susceptible to a range of penicillins and cephalosporins. Restoration of in vivo susceptibility of MRSA to methicillin is also demonstrated using a sepsis animal model by co‐administering methicillin along with celastrol at a much lower amount than that of methicillin. The results suggest a novel approach for developing potentiators for major classes of antibiotics by exploring molecules that re‐program metabolic pathways to reverse β‐lactam‐resistant strains to susceptible strains.