Orchestrated metal-coordinated carrier-free celastrol hydrogel intensifies T cell activation and regulates response to immune checkpoint blockade for synergistic chemo-immunotherapy.

The challenges generated by insufficient T cell activation and infiltration have constrained the application of immunotherapy. Making matters worse, the complex tumor microenvironment (TME), resistance to apoptosis collectively poses obstacles for cancer treatment. The carrier-free small molecular self-assembly strategy is a current research hotspot to overcome these challenges. This strategy can transform multiple functional agents into sustain-released hydrogel without the addition of any excipients. Herein, a coordination and hydrogen bond mediated tricomponent hydrogel (Cel hydrogel) composed of glycyrrhizic acid (GA), copper ions (Cu2+) and celastrol (Cel) was initially constructed. The hydrogel can regulate TME by chemo-dynamic therapy (CDT), which increases reactive oxygen species (ROS) in conjunction with GA and Cel, synergistically expediting cellular apoptosis. What's more, copper induced cuproptosis also contributes to the anti-tumor effect. In terms of regulating immunity, ROS generated by Cel hydrogel can polarize tumor-associated macrophages (TAMs) into M1-TAMs, Cel can induce T cell proliferation as well as activate DC mediated antigen presentation, which subsequently induce T cell proliferation, elevate T cell infiltration and enhance the specific killing of tumor cells, along with the upregulation of PD-L1 expression. Upon co-administration with aPD-L1, this synergy mitigated both primary and metastasis tumors, showing promising clinical translational value.

ROS-triggered and macrophage-targeted micelles modulate mitochondria function and polarization in obesity.

Inflammation involving adipose macrophages is an important inducer of obesity. Regulating macrophages polarization and improving the inflammatory microenvironment of adipose tissue is a new strategy for the treatment of obesity. An amphiphilic chondroitin sulfate phenylborate derivative (CS-PBE) was obtained by modifying the main chain of chondroitin sulfate with the hydrophobic small molecule phenylborate. Using CS-PBE self-assembly, macrophage targeting, reactive oxygen species (ROS) release and celastrol (CLT) encapsulation were achieved. The cytotoxicity, cellular uptake, internalization pathways and transmembrane transport efficiency of CS-PBE micelles were studied in Caco-2 and RAW264.7 cells. Hemolysis and organotoxicity tests were performed to assess the safety of the platform, while its therapeutic efficacy was investigated in high-fat diet-induced obese mice. Multifunctional micelles with macrophage targeting and ROS clearance capabilities were developed to improve the efficacy of CLT in treating obesity.In vitrostudies indicated that CS-PBE micelles had better ability to target M1 macrophages, better protective effects on mitochondrial function, better ability to reduce the number of LPS-stimulated M1 macrophages, better ability to reduce the number of M2 macrophages, and better ability to scavenge ROS in inflammatory macrophages.In vivostudies have shown that CS-PBE micelles improve inflammation and significantly reduce toxicity of CLT in the treatment of obesity. In summary, CS-PBE micelles could significantly improve the ability to target inflammatory macrophages and scavenge ROS in adipose tissue to alleviate inflammation, suggesting that CS-PBE micelles are a highly promising approach for the treatment of obesity.

Asiatic acid reduces lipopolysaccharides-induced pulp inflammation through activation of nuclear factor erythroid 2-related factor 2 in rats.

Background: Dental pulp inflammation, often initiated by Gram-negative microorganisms and lipopolysaccharides (LPS), can lead to pulpitis and, subsequently, dental pulp necrosis, compromising tooth structure and increasing susceptibility to fracture. Asiatic acid, derived from Centella asiatica, has demonstrated pharmacological properties, including anti-inflammatory and antioxidant effects, making it a potential candidate for mitigating LPS-induced pulp inflammation. This in vivo study aims to investigate the impact of Asiatic acid on the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in Rattus norvegicus with LPS-induced pulp inflammation. Methods: This quasi-laboratory experimental in vivo study employed a post-test-only control group design to investigate the effects of Asiatic acid on LPS-induced pulp inflammation in Wistar rats. Thirty rats were randomly divided into six groups subjected to various interventions. LPS was administered to all groups for 6 h except the standard control group (CG, n = 5). The negative control group (NCG, n = 5) received only glass ionomer cement. The positive control group (PCG, n = 5) received Eugenol with glass ionomer cement. Intervention groups 1, 2, and 3 (IG1, IG2, IG3; n = 5 each) received Asiatic acid at concentrations of 0.5%, 1%, and 2%, respectively, with glass ionomer cement. Dental pulp inflammation was confirmed through immunological (tumor necrosis factor alpha (TNF-α) levels), histopathological (inflammatory parameters), and physiological (pain assessment using the rat grimace scale) analyses. Additionally, Nrf2 levels were examined using enzyme-linked immunosorbent assay (ELISA). Results: Asiatic acid administration significantly influenced Nrf2 levels in rats with LPS-induced pulp inflammation. Nrf2 levels were significantly higher in groups treated with 0.5% (IG1) (8.810 ± 1.092 ng/mL; p = 0.047), 1.0% (IG2) (9.132 ± 1.285 ng/mL; p = 0.020), and 2.0% (IG3) (11.972 ± 1.888 ng/mL; p = 0.000) Asiatic acid compared to NCG (7.146 ± 0.706). Notably, Nrf2 levels were also significantly higher in the 2.0% Asiatic acid group (IG3) compared to the PCG treated with Eugenol (8.846 ± 0.888 ng/mL; p = 0.001), as well as IG1 (p = 0.001) and IG2 (p = 0.002). However, no significant difference was observed between administering 0.5% Asiatic acid (IG1), 1.0% Asiatic acid (IG2), and Eugenol (PCG). Conclusion: This research showed that Asiatic acid significantly impacted the Nrf2 levels in rats with LPS-induced pulp inflammation. This suggests that it has the potential to be used as a therapeutic agent for reducing dental pulp inflammation. These findings support the need to further explore Asiatic acid as a promising intervention for maintaining dental pulp health.

Lupeol stimulates iNOS, TNF-α, and IL-10 expression in the U937 cell line infected with old-world Leishmania donovani.

OBJECTIVE: Visceral leishmaniasis is a neglected tropical disease that can be lethal if not treated. The available medicines have severe side effects, such as toxicity and drug resistance. Various investigations are looking into new anti-leishmanial compounds from natural products that have little impact on host cells. Lupeol, a triterpenoid present in the flora of many edible plants, has been shown to have antimicrobial properties. The present study investigated the immunomodulatory effects of lupeol on U937 macrophages infected with Leishmania donovani, focusing on the expression of key cytokines and enzymes involved in the immune response. METHODS: U937 macrophages were infected with Leishmania donovani amastigotes and treated with varying concentrations of lupeol throughout three days. The expression levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-α), and interleukin-10 (IL-10) were measured using real-time polymerase chain reaction (RT-PCR). A positive simulation of gene expression was estimated using ΔΔCT to assess relative expression. RESULTS: The results demonstrated that lupeol significantly upregulated iNOS and TNF-α expression, especially at higher concentrations, indicating enhanced pro-inflammatory and anti-leishmanial activity. Interestingly, IL-10 expression also increased, suggesting a complex immunomodulatory role of lupeol that involves both pro-inflammatory and anti-inflammatory pathways. Pearson correlation analysis revealed a strong association between iNOS and TNF-α (0.97692), as well as a moderate correlation between iNOS and IL-10 (0.51603). CONCLUSION: These findings suggest that lupeol may promote a balanced immune response, enhancing the body's ability to combat L. donovani while potentially mitigating excessive inflammation. Lupeol can potentially serve as a novel therapeutic agent against visceral leishmaniasis.

Study of Pentacyclic Triterpenes from Lyophilised Aguaje: Anti-Inflammatory and Antioxidant Properties.

Mauritia flexuosa (M. flexuosa), commonly known as Aguaje or Moriche palm, is traditionally recognised in South America for its medicinal properties, particularly for its anti-inflammatory and antioxidant effects. However, the bioactive compounds responsible for these effects have not been thoroughly investigated. This study aims to isolate and characterise pentacyclic triterpenoid compounds from M. flexuosa and to evaluate their therapeutic potential. Using various chromatographic and spectroscopic techniques including Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS), three pentacyclic triterpenoid compounds were successfully isolated. Among them, compound 1 (3,11-dioxours-12-en-28-oic acid) exhibited notable bioactivity, significantly inhibiting the activation of Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) (IC50 = 7.39-8.11 µM) and of Nitric Oxide (NO) (IC50 = 4.75-6.59 µM), both of which are key processes in inflammation. Additionally, compound 1 demonstrated potent antioxidant properties by activating the antioxidant enzyme Superoxide Dismutase (SOD) (EC50 = 1.87 µM) and the transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2) (EC50 = 243-547.59 nM), thus showing its potential in combating oxidative stress. This study is the first to isolate and characterise the three compounds from M. flexuosa, suggesting that compound 1 could be a promising candidate for the development of safer and more effective therapies for inflammatory and oxidative stress-related diseases.

Lupeol-3-carbamate Derivatives: Synthesis and Biological Evaluation as Potential Antitumor Agents.

In the following study, a series of new lupeol-3-carbamate derivatives were synthesized, and the structures of all the newly derived compounds were characterized. The new compounds were screened to determine their anti-proliferative activity against human lung cancer cell line A549, human liver cancer cell line HepG2, and human breast cancer cell line MCF-7. Most of the compounds were found to show better anti-proliferative activity in vitro than lupeol. Among them, obvious anti-proliferation activity (IC50 = 5.39~9.43 µM) was exhibited by compound 3i against all three tumor cell lines. In addition, a salt reaction was performed on compound 3k (IC50 = 13.98 µM) and it was observed that the anti-proliferative activity and water solubility of compound 3k·CH3I (IC50 = 3.13 µM), were significantly enhanced subsequent to the salt formation process. The preliminary mechanistic studies demonstrated that apoptosis in HepG2 cells was induced by compound 3k·CH3I through the inhibition of the PI3K/AKT/mTOR pathway. In conclusion, a series of new lupeol-3-carbamate derivatives were synthesized via the structural modification of the C-3 site of lupeol, thus laying a theoretical foundation for the design of this new anticancer drug.

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.

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.

EpCAM-targeted betulinic acid analogue nanotherapy improves therapeutic efficacy and induces anti-tumorigenic immune response in colorectal cancer tumor microenvironment.

BACKGROUND: Betulinic acid (BA) has been well investigated for its antiproliferative and mitochondrial pathway-mediated apoptosis-inducing effects on various cancers. However, its poor solubility and off-target activity have limited its utility in clinical trials. Additionally, the immune modulatory role of betulinic acid analogue in the tumor microenvironment (TME) is largely unknown. Here, we designed a potential nanotherapy for colorectal cancer (CRC) with a lead betulinic acid analogue, named as 2c, carrying a 1,2,3-triazole-moiety attached to BA through a linker, found more effective than BA for inhibiting CRC cell lines, and was chosen here for this investigation. Epithelial cell adhesion molecule (EpCAM) is highly overexpressed on the CRC cell membrane. A single-stranded short oligonucleotide sequence, aptamer (Apt), that folds into a 3D-defined architecture can be used as a targeting ligand for its specific binding to a target protein. EpCAM targeting aptamer was designed for site-specific homing of aptamer-conjugated-2c-loaded nanoparticles (Apt-2cNP) at the CRC tumor site to enhance therapeutic potential and reduce off-target toxicity in normal cells. We investigated the in vitro and in vivo therapeutic efficacy and anti-tumorigenic immune response of aptamer conjugated nanotherapy in CRC-TME. METHODS: After the characterization of nanoengineered aptamer conjugated betulinic acid nanotherapy, we evaluated therapeutic efficacy, tumor targeting efficiency, and anti-tumorigenic immune response using cell-based assays and mouse and rat models. RESULTS: We found that Apt-2cNP improved drug bioavailability, enhanced its biological half-life, improved antiproliferative activity, and minimized off-target cytotoxicity. Importantly, in an in vivo TME, Apt-2cNP showed promising signs of anti-tumorigenic immune response (increased mDC/pDC ratio, enhanced M1 macrophage population, and CD8 T-cells). Furthermore, in vivo upregulation of pro-apoptotic while downregulation of anti-apoptotic genes and significant healing efficacy on cancer tissue histopathology suggest that Apt-2cNP had predominantly greater therapeutic potential than the non-aptamer-conjugated nanoparticles and free drug. Moreover, we observed greater tumor accumulation of the radiolabeled Apt-2cNP by live imaging in the CRC rat model. CONCLUSIONS: Enhanced therapeutic efficacy and robust anti-tumorigenic immune response of Apt-2cNP in the CRC-TME are promising indicators of its potential as a prospective therapeutic agent for managing CRC. However, further studies are warranted.

Scaffold Hopping of Pristimerin Provides Derivatives Containing a Privileged Quinoxaline Substructure as Potent Autophagy Inducers in Breast Cancer Cells.

Pristimerin is a natural triterpenoid that has received much attention from medicinal chemists for its multiple biological activities. However, structural modifications of pristimerin, especially those aimed at discovering antitumor agents, are relatively limited. In this study, two series of pristimerin derivatives containing phenyloxazole and quinoxaline moieties, respectively, were designed via the scaffold hopping strategy. The target compounds were synthesized and analyzed for their cytotoxic activities in vitro using the MTT assay. The most potent cytotoxic compound (21o) significantly inhibited the proliferation of MCF-7 cells with an IC50 value of 2.0 µM, 1.5-fold more potent than pristimerin (IC50 = 3.0 µM). Compared with pristimerin, compound 21o displayed the greatest improvement in selectivity (25.7-fold) against the MCF-7 and MCF-10A cell lines. Transmission electron microscopy, monodansylcadaverine and DCFH-DA staining, Western blotting, and different inhibitor assays were performed to elucidate the mechanism of action of compound 21o. Compound 21o induced autophagy-mediated cell death in MCF-7 cells by activating the ROS/JNK signaling pathway. Therefore, incorporating a quinoxaline substructure into pristimerin could be advantageous for enhancing its cytotoxic activity. Compound 21o may serve as a lead compound for developing new therapies to treat breast cancer.

Engineered Carrier-Free Nanosystem-Induced In Situ Therapeutic Vaccines for Potent Cancer Immunotherapy.

In situ vaccines that can stimulate tumor immune response have emerged as a breakthrough in antitumor therapy. However, the immunosuppressed tumor microenvironment and insufficient infiltration of immune cells lead to ineffective antitumor immunity. Hence, a biomimetic carrier-free nanosystem (BCC) to induce synergistic phototherapy/chemotherapy-driven in situ vaccines was designed. A carrier-free nanosystem was developed using phototherapeutic reagents CyI and celastrol as raw materials. In vitro and in vivo studies have shown that under NIR light irradiation, BCC-mediated photo/chemotherapy not only accelerates the release of drugs to deeper parts of tumors, achieving timing and light-controlled drug delivery to result in cell apoptosis, but also effectively stimulates the antitumor response to induce in situ vaccine, which could invoke long-lasting antitumor immunity to inhibit tumor metastasis and eliminate distant tumor. This therapeutic strategy holds promise for priming robust innate and adaptive immune responses, arresting cancer progression, and inducing tumor dormancy.

Manniosides G-J, New Ursane- and Lupane-Type Saponins from Schefflera mannii (Hook.f.) Harms.

Four previously unreported triterpenoid saponins named 3ß-hydroxy-23-oxours-12-en-28-oic acid 28-O-ß-D-glucopyranosyl ester (mannioside G) (1), 23-O-acetyl-3ß-hydroxyurs-12-en-28-oic acid 28-O-ß-D-glucopyranosyl ester (mannioside H) (2), ursolic acid 28-O-[α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranosyl] ester (mannioside I) (3), and 3ß-hydroxy-23-oxolup-20(29)-en-28-oic acid 28-O-ß-D-glucopyranosyl ester (mannioside J) (4) were isolated as minor constituents from the EtOAc soluble fraction of the MeOH extract of the leaves of Schefflera mannii along with the known compounds 23-hydroxyursolic acid 28-O-ß-D-glucopyranosyl ester (5), ursolic acid 28-O-ß-D-glucopyranosyl ester (6), pulsatimmoside B (7) betulinic acid 28-O-[α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranosyl] ester (8), 23-hydroxy-3-oxo-urs-12-en-28-oic acid (9), hederagenin (10), ursolic acid (11), betulinic acid (12), and lupeol (13). Their structures were elucidated by a combination of 1D and 2D NMR analysis and mass spectrometry. The MeOH extract, the EtOAc and n-BuOH fractions, and some of the isolated compounds were evaluated for their antibacterial activity against four bacteria: Staphylococcus aureus ATCC1026, Staphylococcus epidermidis ATCC 35984, Escherichia coli ATCC10536, and Klepsiella pnemoniae ATCC13882. They were also screened for their antioxidant properties, but no significant results were obtained.

Celastrol alleviates atopic dermatitis by regulating Ezrin-mediated mitochondrial fission and fusion.

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-1ß, 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.

The beneficial effects of lupeol on particulate matter-mediated pulmonary inflammation.

Particulate matter (PM) poses significant health risks, especially fine particles (PM2.5) that can cause severe lung injuries. Lupeol, a phytosterol from medicinal plants, has potential anti-cancer properties. This study investigated lupeol's protective effects against PM2.5-induced lung damage. Mice received lupeol following intratracheal PM2.5 exposure. Results showed lupeol reduced lung damage, lowered wet/dry (W/D) weight ratio, and suppressed increased permeability caused by PM2.5. Additionally, lupeol decreased plasma inflammatory cytokines, total protein concentration in bronchoalveolar lavage fluid (BALF), and PM2.5-induced lymphocyte proliferation. Lupeol also reduced expression of toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), and autophagy-related proteins microtubule-associated protein 1 A/1 B-light chain 3 (LC3) II and Beclin 1, while increasing phosphorylated mammalian target of rapamycin (mTOR) phosphorylation. These findings suggest lupeol's potential as a therapeutic agent for PM2.5-induced lung damage via modulation of the TLR4-MyD88 and mTOR-autophagy pathways.

Uvaol ameliorates lipid deposition in hyperlipidemic hepatocytes by suppressing protein-tyrosine phosphatase 1B/ER stress signaling.

Uvaol (UV), a pentacyclic triterpene found in olives and virgin olive oil, is known for its anti-inflammatory and antioxidant effects in various disease models. While olive oil is reported to reduce obesity and insulin resistance, the specific impact of UV on liver lipid metabolism and its molecular mechanisms are not fully understood. In this study, hepatic lipid accumulation was measured using oil red O staining, and protein expression levels in liver cells were assessed via Western blot analysis. Apoptosis was evaluated through cell viability and caspase 3 activity assays. UV treatment reduced lipid accumulation, fatty acid uptake, apoptosis, and ER stress in palmitate-treated liver cells. Additionally, UV enhanced fatty acid oxidation. Mechanistically, increased SIRT6 expression and autophagy were observed in UV-treated cells. SIRT6-targeted siRNA or 3-methyladenine blocked the effects of UV in hyperlipidemic cells. In conclusion, UV improves SIRT6/autophagy signaling, reducing lipid deposition and apoptosis in liver cells under high lipid conditions. This in vitro study provides strong evidence for potential therapeutic strategies for hepatic steatosis.

Cellular and molecular mechanisms underlying the potential of betulinic acid in cancer prevention and treatment.

BACKGROUND: Betulinic acid (BA), which is a pentacyclic triterpenoid found in the bark of plane, birch, and eucalyptus trees, has emerged as a compound of significant interest in scientific research due to its potential therapeutic applications. BA has a range of well-documented pharmacological and biological effects, including antibacterial, immunomodulatory, diuretic, antiviral, antiparasitic, antidiabetic, and anticancer activities. Although numerous research studies have explored the potential anticancer effects of BA, there is a noticeable gap in the literature, highlighting the need for a more up-to-date and comprehensive evaluation of BA's anticancer potential. PURPOSE: The aim of this work is to critically assess the reported cellular and molecular mechanisms underlying the cancer preventive and therapeutic effects of BA. METHODS: Relevant research on the inhibitory effects of BA against cancerous cells was searched using Science Direct, Scopus, Web of Science, and PubMed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: The anticancer properties of BA are mediated by the activation of cell death and cell cycle arrest, production of reactive oxygen species, increased mitochondrial permeability, modulation of nuclear factor-κB and Bcl-2 family signaling. Emerging evidence also underscores the combined anticancer effects of BA with other natural bioactive compounds or approved drugs. Notably, several novel BA nanoformulations have been found to exhibit encouraging antineoplastic activities. CONCLUSION: BA, whether used alone or in combination, or as a form of nanoformulation, shows significant potential for cancer prevention and treatment. Nevertheless, further detailed studies are necessary to confirm the therapeutic effectiveness of this natural compound.

In vitro efficacy of different concentrations of lupeol on old world Leishmania donovani.

Leishmaniosis is a tropical neglected parasitic disease that is endemic in many countries, including Middle East, with no existing effective vaccines. The bite of female sand-fly transmits the causative agent, Leishmania spp., to humans. High toxicity, resistance and treatment failure of the available chemotherapy against visceral leishmaniosis demands the investigation of new anti-leishmanial compounds. Lupeol is a form of triterpene isolated from several medicinal plants and possesses an antimicrobial property. In this study, cytotoxic effect of lupeol was screened against the mammalian amastigotes form and insect promastigote form of Leishmania donovani, following three cycles of incubation at different concentrations by MTT assay. Results revealed the in vitro anti-leishmanial effect of lupeol on both forms of the parasite where significant decline in promastigotes and amastigotes growth was observed. This was conducted along three times of follow up (24, 48, 72) hours, in comparison to the classical sodium stibogluconate treatment. Cell viability was calculated and the minimum IC50 was detected after 48 hours for amastigotes and 24 hours for promastigotes, 12.125 µM, 102.78 µM, respectively. Given the severity of visceral leishmaniosis and the toxicity of conventional chemotherapies, the anti-leishmanial activity of lupeol suggested a promising compound for additional clinical trials.

Celastrol exerts antiarrhythmic effects in chronic heart failure via NLRP3/Caspase-1/IL-1ß signaling pathway.

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-1ß pathway.

The effect of celastrol in combination with 5-fluorouracil on proliferation and apoptosis of gastric cancer cell lines.

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.

Prodrug-inspired adenosine triphosphate-activatable celastrol-Fe(III) chelate for cancer therapy.

Celastrol (CEL), an active compound isolated from the root of Tripterygium wilfordii, exhibits broad anticancer activities. However, its poor stability, narrow therapeutic window and numerous adverse effects limit its applications in vivo. In this study, an adenosine triphosphate (ATP) activatable CEL-Fe(III) chelate was designed, synthesized, and then encapsulated with a reactive oxygen species (ROS)-responsive polymer to obtain CEL-Fe nanoparticles (CEL-Fe NPs). In normal tissues, CEL-Fe NPs maintain structural stability and exhibit reduced systemic toxicity, while at the tumor site, an ATP-ROS-rich tumor microenvironment, drug release is triggered by ROS, and antitumor potency is restored by competitive binding of ATP. This intelligent CEL delivery system improves the biosafety and bioavailability of CEL for cancer therapy. Such a CEL-metal chelate strategy not only mitigates the challenges associated with CEL but also opens avenues for the generation of CEL derivatives, thereby expanding the therapeutic potential of CEL in clinical settings.