Oridonin and its derivatives for cancer treatment and overcoming therapeutic resistance

Discovery of a Natural Ent-Kaurene Diterpenoid Oridonin as an E3 Ligase Recruiter for PROTACs

PROTACs have emerged as a therapeutic modality for the targeted degradation of proteins of interest (POIs). Central to PROTAC technology are the E3 ligase recruiters, yet only a few of them have been identified due to the lack of ligandable pockets in ligases, especially among single-subunit ligases. We propose that binders of partner proteins of single-subunit ligases could be repurposed as new ligase recruiters. MDM2 is a single-subunit ligase overexpressed in tumors. Nucleolin (NCL) is an MDM2 partner protein that displays a similar tumor-specific overexpression pattern and nuclear-cytoplasmic shuttling role to MDM2. Furthermore, NCL is selectively translocated on the tumor cell surface, where it acts as an internalization receptor for its binders. We reveal that the NCL-binding Oridonin (Ori), a natural ent-kaurene diterpenoid, is capable of recruiting MDM2 by employing NCL as a molecular bridge. We design Ori-based PROTACs for modulating oncogenic POIs, including BRD4 and EGFR. These PROTACs direct the assembly of MDM2-NCL-PROTAC-POI complexes to induce proteasomal degradation of POIs and tumor shrinkage. In addition to its role as a ligase engaged by PROTACs, MDM2, along with its homologue MDMX, plays a nonredundant function in inhibiting p53 activity. Dual inhibition of MDM2/X is proposed as a promising antitumor strategy. We demonstrate that Ori also recruits MDMX in an NCL-dependent manner. Ori-based homo-PROTACs induce MDM2/X dual degradation and attenuate tumor progression. Our findings prove the feasibility of repurposing the binders of ligase partner proteins as new ligase recruiters in PROTACs and highlight the potential of Ori as an MDM2/X recruiter.

The NLRP3 inflammasome: A central player in multiple sclerosis

Multiple sclerosis (MS) is a neurological autoimmune condition associated with many symptoms including spasticity, pain, limb numbness and weakness. It is characterised by inflammatory demyelination and axonal degeneration of the brain and spinal cord. A range of disease-modifying therapies (DMTs) are available to suppress inflammatory disease activity in MS, however, there is a pressing need for new therapeutic avenues as DMTs have a limited ability to suppress confirmed disability progression. A body of literature indicates that innate immune inflammation is linked to MS progression. The nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain containing protein 3 (NLRP3) inflammasome has a well-established function in innate immunity which is closely associated with the pathogenesis of neuroinflammatory conditions. Evidence suggests that the inflammasome may be a therapeutic target in disorders such as MS and at present, inhibitors of the NLRP3 inflammasome are in pre-clinical development. Therefore, this review systematically highlights the pathogenic role of inflammasomes in MS, presenting an overview of research evidence linking inflammasome-related polymorphisms to MS susceptibility, and gathering evidence investigating NLRP3 biomarkers in MS. The role of the NLRP3 inflammasome in murine models of MS is furthermore discussed. Finally, a significant component of this review focuses on evidence that NLRP3 signalling components are novel drug targets in MS. Overall this review defines the role of the inflammasome in MS pathogenesis and identifies inflammasome inhibitor targets that warrant full investigation in MS and related disorders.

Rabdosia rubescens (Hemsl.) H. Hara: A potent anti-tumor herbal remedy - Botany, phytochemistry, and clinical applications and insights

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese herbal medicine has unique advantages as anti-cancer drugs and adjuvant therapies. Rabdosia rubescens (Hemsl.) H. Hara (R. rubescens) is a traditional medicinal plant known for its anti-inflammatory, antioxidant, antibacterial, anti-angiogenic and antitumor properties. The antitumor activity of R. rubescens is widely recognized among the folk communities in Henan Province, China.

AIM OF THE STUDY

This study reviews the botany, ethnopharmacology, phytochemistry, anti-tumor active ingredients, mechanisms, and clinical applications of R. rubescens, aiming to provide a comprehensive understanding for its use as an anti-cancer drug and adjuvant therapy.

MATERIALS AND METHODS

We systematically searched the literature in PubMed, Web of Science, and CNKI using the following keywords: "Rabdosia rubescens", "Isodon rubescens", "traditional application", "anti-tumor", "phytochemistry", "anti-tumor active compounds", "oridonin" and "clinical application". The search covered publications from 1997 to 2024. Inclusion criteria included original studies or reviews focusing on the anti-tumor properties of R. rubescens or its active components. Exclusion criteria included studies related to non-R. rubescens applications.

RESULTS

R. rubescens is a perennial herbaceous plant in the family Lamiaceae, mainly found in central and southern China. Historically, it has been used to treat conditions such as sore throat, cough, and excess phlegm. The plant contains various compounds, including diterpenes, triterpenes, steroids, flavonoids, phenolic acids, essential oils, amino acids, alkaloids, and polysaccharides, with diterpenes, triterpenes, flavonoids, and phenolic acids being the most active. This review identifies 50 compounds with anti-tumor properties, comprising 34 diterpenes, 2 triterpenes, 7 flavonoids, and 7 phenolic acids. Notably, besides oridonin and ponicidin, the ent-kaurane diterpenoids (20S)-11β,14β,20-trihydroxy-7α,20-epoxy-ent-kaur-16-en15-one and (20S)-11β,14β-dihydroxy-20-ethoxy7α,20-epoxy-ent-kaur-16-en-15-one demonstrate significant anti-tumor activity, attributed to their carbonyl group at C-15, hydroxyl group at C-1, and OEt group at C-20. Mechanistically, R. rubescens combats tumors by blocking the tumor cell cycle, promoting apoptosis, inhibiting cell migration and angiogenesis, inducing ferroptosis, reversing drug resistance, and enhancing radiosensitivity in tumor cells. Clinically, R. rubescens is available in various forms, including tablets, drops, syrups, capsules, and lozenges, and is primarily used for tonsillitis, pharyngitis, and stomatitis. According to the 2020 edition of the Pharmacopoeia of China, R. rubescens tablets are recognized as an adjuvant therapy for cancer. Clinical studies indicate that R. rubescens syrup, tablets, and thermal therapy can enhance cancer patient survival rates and lower tumor recurrence rates.

CONCLUSIONS

Given its traditional and modern uses, active anti-tumor components, and mechanisms, R. rubescens is a promising resource in traditional Chinese medicine for anti-tumor therapy. To realize its full potential, future research should explore additional active anti-tumor compounds beyond oridonin and ponicidin. For these key components, studies should focus on structural modifications to identify new active molecules and essential anti-tumor structures. Clinically, it is important to investigate how R. rubescens interacts with other Chinese herbs in anti-tumor formulations to enhance treatment efficacy and guide appropriate clinical use. Furthermore, future studies should undergo ethical review and include larger-scale randomized controlled trials to validate the efficacy of R. rubescens in treating tumors, thereby promoting its role as an anti-tumor traditional Chinese medicine.

Enhancing cancer therapy: advanced nanovehicle delivery systems for oridonin

Oridonin (ORI), an ent-kaurane diterpenoid derived from Rabdosia rubescens (Hemsl.) H.Hara, serves as the primary bioactive component of this plant. It demonstrates a broad spectrum of therapeutic activities, including moderate to potent anticancer properties, alongside anti-inflammatory, antibacterial, antifibrotic, immunomodulatory, and neuromodulatory effects, thus influencing diverse biological processes. However, its clinical potential is significantly constrained by poor aqueous solubility and limited bioavailability. In alignment with the approach of developing drug candidates from natural compounds, various strategies, such as structural modification and nanocarrier systems, have been employed to address these challenges. This review provides an overview of ORI-based nano-delivery systems, emphasizing their potential to improve the clinical applicability of oridonin in oncology. Although some progress has been made in advancing ORI nano-delivery research, it remains insufficient for clinical implementation, necessitating further investigation.

Terpenoids: Unlocking Their Potential on Cancer Glucose Metabolism

Cancer incidence has increased globally and has become the leading cause of death in the majority of countries. Many cancers have altered energy metabolism pathways, such as increased glucose uptake and glycolysis, as well as decreased oxidative phosphorylation. This is known as the Warburg effect, where cancer cells become more reliant on glucose to generate energy and produce lactate as an end product, even when oxygen is present. These are attributed to the overexpression of key glycolytic enzymes, glucose transporters, and related signaling pathways that occur in cancer cells. Therefore, overcoming metabolic alterations in cancer cells has recently become a target for therapeutic approaches. Natural products have played a key role in drug discovery, especially for cancer and infectious diseases. In this review, we are going to focus on terpenoids, which are gradually gaining popularity among drug researchers due to their reported anti-cancer effects via cell cycle arrest, induction of apoptosis, reduction of proliferation, and metastasis. This review summarizes the potential of 13 terpenoid compounds as anti-glycolytic inhibitors in different cancer models, primarily by inhibiting the glucose uptake and the generation of lactate, as well as by downregulating enzymes associated to glycolysis. As a conclusion, disruption of cancer cell glycolysis may be responsible for the anti-cancer activity of terpenoids.

H2S-releasing oridonin derivatives with improved antitumor activity by inhibiting the PI3K/AKT pathway

Activating programmed cell death by delivering hydrogen sulfide (H2S) has emerged as a promising strategy for tumor therapy. Oridonin serves as a lead compound for drug development due to its unique scaffold and wide-ranging biological effects, especially its antitumor properties. Based on the previous structure-activity relationship studies, 33 novel 1-O/14-O H2S-releasing oridonin derivatives were synthesized. Particularly, 11a exhibited the most potent antiproliferative activity, effectively inhibiting colony formation, migration and invasion in both MCF-7 and MIA-PaCa-2 cells. It also inhibited the PI3K/AKT pathway to regulate the expression of Bax and Bcl-2, thereby initiating the Caspase cascade to activate mitochondrial mediated apoptosis. Furthermore, 11a suppressed tumor growth in breast cancer syngeneic models with no apparent toxicity.

New 3-acyl derivatives of glaucocalyxin A: designed, synthesis and in vitro antibacterial activities

To discover novel antimicrobial drug, 22 novel acylated derivatives were synthesized by A-ring modification of glaucocalyxin A. The structures of these derivatives were confirmed by NMR and MS data. In vitro antimicrobial activity of these compounds was evaluated against E. faecium, E. faecalis, MRSA, E. coli, A. baumannii and K. pneumoniae. The results showed compound 3d against E. faecium, E. faecalis and MRSA with a minimum inhibitory concentration of 4 μg/ml. And further molecular docking revealed that compound 3d has a higher binding affinity. In conclusion, compound 3d has the potential to develop into a new drug against drug-resistant bacteria.

The therapeutic potential of andrographolide in cancer treatment

Cancer poses a substantial global health challenge, necessitating the widespread use of chemotherapy and radiotherapy. Despite these efforts, issues like resistance development and severe side effects remain. As such, the search for more effective alternatives is critical. Andrographolide, a naturally occurring compound, has recently gained attention for its extensive biological activities. This review explores the role of andrographolide in cancer therapy, especially focusing on the molecular mechanisms that drive its anti-tumor properties. It also examines innovative methods to enhance andrographolide's bioavailability, thus boosting its effectiveness against cancer. Notably, andrographolide has potential for use in combination with various clinical drugs, and both preclinical and clinical studies provide strong evidence supporting its broader anticancer applications. Additionally, this paper proposes future research directions for andrographolide's anti-cancer effects and discusses the challenges in its clinical usage along with current research efforts to address these issues. In summary, this review underscores andrographolide's potential roles and contributes to the development of improved cancer treatment strategies.

Network Pharmacology and in vitro Experimental Verification on Intervention of Oridonin on Non-Small Cell Lung Cancer

OBJECTIVE

To explore the key target molecules and potential mechanisms of oridonin against non-small cell lung cancer (NSCLC).

METHODS

The target molecules of oridonin were retrieved from SEA, STITCH, SuperPred and TargetPred databases; target genes associated with the treatment of NSCLC were retrieved from GeneCards, DisGeNET and TTD databases. Then, the overlapping target molecules between the drug and the disease were identified. The protein-protein interaction (PPI) was constructed using the STRING database according to overlapping targets, and Cytoscape was used to screen for key targets. Molecular docking verification were performed using AutoDockTools and PyMOL software. Using the DAVID database, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted. The impact of oridonin on the proliferation and apoptosis of NSCLC cells was assessed using cell counting kit-8, cell proliferation EdU image kit, and Annexin V-FITC/PI apoptosis kit respectively. Moreover, real-time quantitative PCR and Western blot were used to verify the potential mechanisms.

RESULTS

Fifty-six target molecules and 12 key target molecules of oridonin involved in NSCLC treatment were identified, including tumor protein 53 (TP53), Caspase-3, signal transducer and activator of transcription 3 (STAT3), mitogen-activated protein kinase kinase 8 (MAPK8), and mammalian target of rapamycin (mTOR). Molecular docking showed that oridonin and its key target molecules bind spontaneously. GO and KEGG enrichment analyses revealed cancer, apoptosis, phosphoinositide-3 kinase/protein kinase B (PI3K/Akt), and other signaling pathways. In vitro experiments showed that oridonin inhibited the proliferation, induced apoptosis, downregulated the expression of Bcl-2 and Akt, and upregulated the expression of Caspase-3.

CONCLUSION

Oridonin can act on multiple targets and pathways to exert its inhibitory effects on NSCLC, and its mechanism may be related to upregulating the expression of Caspase-3 and downregulating the expressions of Akt and Bcl-2.

Light-promoted stereoselective late-stage difunctionalization and anti-tumor activity of oridonin

The late-stage difunctionalization of diterpene oridonin by light-promoted direct oxyamination with various O-benzoylhydroxylamines was carried out to afford C16α-N-C17-OBz-oridonin derivatives (1-25) for the first time. Though as a radical reaction, it features high stereoselectivity to only produce C16α-N-C17-OBz-oridonins. The in vitro antiproliferative activity of these C16α-N-C17-OBz-oridonins against the human breast cancer cell lines (MCF-7) was evaluated by MTT assay, showing that most of the synthesized compounds possessed moderate anticancer activity against MCF-7 cell lines superior or similar to the parent compound oridonin. The derivative 25 with a N-methyl-N-(naphthalen-1-ylmethyl) substitution showed better cytotoxicity against MCF-7 cells (IC50 value of 11.75 μM) than oridonin (IC50 value of 17.95 μM).

Natural products reverse cisplatin resistance in the hypoxic tumor microenvironment

Cisplatin is one of the most commonly used drugs for cancer treatment. Despite much progress in improving patient outcomes, many patients are resistant to cisplatin-based treatments, leading to limited treatment efficacy and increased treatment failure. The fact that solid tumors suffer from hypoxia and an inadequate blood supply in the tumor microenvironment has been widely accepted for decades. Numerous studies have shown that a hypoxic microenvironment significantly reduces the sensitivity of tumor cells to cisplatin. Therefore, understanding how hypoxia empowers tumor cells with cisplatin resistance is essential. In the fight against tumors, developing innovative strategies for overcoming drug resistance has attracted widespread interest. Natural products have historically made major contributions to anticancer drug research due to their obvious efficacy and abundant candidate resources. Intriguingly, natural products show the potential to reverse chemoresistance, which provides new insights into cisplatin resistance in the hypoxic tumor microenvironment. In this review, we describe the role of cisplatin in tumor therapy and the mechanisms by which tumor cells generate cisplatin resistance. Subsequently, we call attention to the linkage between the hypoxic microenvironment and cisplatin resistance. Furthermore, we summarize known and potential natural products that target the hypoxic tumor microenvironment to overcome cisplatin resistance. Finally, we discuss the current challenges that limit the clinical application of natural products. Understanding the link between hypoxia and cisplatin resistance is the key to unlocking the full potential of natural products, which will serve as new therapeutic strategies capable of overcoming resistance.

Natural products for enhancing the sensitivity or decreasing the adverse effects of anticancer drugs through regulating the redox balance

Redox imbalance is reported to play a pivotal role in tumorigenesis, cancer development, and drug resistance. Severe oxidative damage is a general consequence of cancer cell responses to treatment and may cause cancer cell death or severe adverse effects. To maintain their longevity, cancer cells can rescue redox balance and enter a state of resistance to anticancer drugs. Therefore, targeting redox signalling pathways has emerged as an attractive and prospective strategy for enhancing the efficacy of anticancer drugs and decreasing their adverse effects. Over the past few decades, natural products (NPs) have become an invaluable source for developing new anticancer drugs due to their high efficacy and low toxicity. Increasing evidence has demonstrated that many NPs exhibit remarkable antitumour effects, whether used alone or as adjuvants, and are emerging as effective approaches to enhance sensitivity and decrease the adverse effects of conventional cancer therapies by regulating redox balance. Among them are several novel anticancer drugs based on NPs that have entered clinical trials. In this review, we summarize the synergistic anticancer effects and related redox mechanisms of the combination of NPs with conventional anticancer drugs. We believe that NPs targeting redox regulation will represent promising novel candidates and provide prospects for cancer treatment in the future.

NLRP3 Negative Regulation Mechanisms in the Resting State and Its Implications for Therapeutic Development

The NACHT-, leucine-rich-repeat-, and pyrin domain-containing protein 3 (NLRP3) is a critical intracellular sensor of the innate immune system that detects various pathogen- and danger-associated molecular patterns, leading to the assembly of the NLRP3 inflammasome and release of interleukin (IL) 1β and IL-18. However, the abnormal activation of the NLRP3 inflammasome has been implicated in the pathogenesis of autoinflammatory diseases such as cryopyrin-associated autoinflammatory syndromes (CAPS) and common diseases such as Alzheimer's disease and asthma. Recent studies have revealed that pyrin functions as an indirect sensor, similar to the plant guard system, and is regulated by binding to inhibitory 14-3-3 proteins. Upon activation, pyrin transitions to its active form. NLRP3 is predicted to follow a similar regulatory mechanism and maintain its inactive form in the cage model, as it also acts as an indirect sensor. Additionally, newly developed NLRP3 inhibitors have been found to inhibit NLRP3 activity by stabilizing its inactive form. Most studies and reviews on NLRP3 have focused on the activation of the NLRP3 inflammasome. This review highlights the molecular mechanisms that regulate NLRP3 in its resting state, and discusses how targeting this inhibitory mechanism can lead to novel therapeutic strategies for NLRP3-related diseases.

In vitro identification of oridonin hybrids as potential anti-TNBC agents inducing cell cycle arrest and apoptosis by regulation of p21, γH2AX and cleaved PARP

TNBC has been recognized as the most highly aggressive breast cancer without chemotherapeutic drugs. A collection of oridonin hybrids consisting of conventional antitumor pharmacophores including nitrogen mustards and adamantane-1-carboxylic acid were synthesized by deletion or blockade of multiple hydroxyl groups and structural rearrangement. Compound 11a showed the most promising anti-TNBC activity with nearly 15-fold more potent antiproliferative effects than oridonin against MDA-MB-231 and HCC1806. Moreover, 11a significantly inhibited HCC1806, MDA-MB-231 and MDA-MB-468 cell proliferation by arresting cells at the G2/M phase in a dose-dependent manner. Furthermore, 11a could trigger dose-dependently early and late apoptosis in those indicated cell lines. More importantly, 11a could significantly increase p21, γH2AX and cleaved PARP accumulation in a dose-dependent manner. Furthermore, compound 11a exhibited better stability than oridonin in a plasma assay. Taken together, all results demonstrated that 11a may warrant further investigation as a promising anticancer drug candidate for the treatment of TNBC.

Hit-to-Lead Optimization of the Natural Product Oridonin as Novel NLRP3 Inflammasome Inhibitors with Potent Anti-Inflammation Activity

Targeting NLRP3 inflammasome with inhibitors is a novel strategy for NLRP3-driven diseases. Herein, hit compound 5 possessing an attractive skeleton was identified from our in-house database of oridonin, and then a potential lead compound 32 was obtained by optimization of 5, displaying two-digit nanomolar inhibition on NLRP3. Moreover, compound 32 showed enhanced safety index (SI) relative to oridonin (IC50 = 77.2 vs 780.4 nM, SI = 40.5 vs 8.5) and functioned through blocking ASC oligomerization and interaction of NLRP3-ASC/NEK7, thereby suppressing NLRP3 inflammasome assembly and activation. Furthermore, diverse agonists-induced activations of NLRP3 could be impeded by compound 32 without altering NLRC4 or AIM2 inflammasome. Crucially, compound 32 possessed tolerable pharmaceutical properties and significant anti-inflammatory activity in MSU-induced gouty arthritis model. Therefore, this work enriched the SAR of NLRP3 inflammasome inhibitors and provided a potential candidate for the treatment of NLRP3-associated diseases.

Glutathione-depleting Liposome Adjuvant for Augmenting the Efficacy of a Glutathione Covalent Inhibitor Oridonin for Acute Myeloid Leukemia Therapy

BACKGROUND

Discrepancies in the utilization of reactive oxygen species (ROS) between cancer cells and their normal counterparts constitute a pivotal juncture for the precise treatment of cancer, delineating a noteworthy trajectory in the field of targeted therapies. This phenomenon is particularly conspicuous in the domain of nano-drug precision treatment. Despite substantial strides in employing nanoparticles to disrupt ROS for cancer therapy, current strategies continue to grapple with challenges pertaining to efficacy and specificity. One of the primary hurdles lies in the elevated levels of intracellular glutathione (GSH). Presently, predominant methods to mitigate intracellular GSH involve inhibiting its synthesis or promoting GSH efflux. However, a conspicuous gap remains in the absence of a strategy capable of directly and efficiently clearing GSH.

METHODS

We initially elucidated the chemical mechanism underpinning oridonin, a diminutive pharmacological agent demonstrated to perturb reactive oxygen species, through its covalent interaction with glutathione. Subsequently, we employed the incorporation of maleimide-liposomes, renowned for their capacity to disrupt the ROS delivery system, to ameliorate the drug's water solubility and pharmacokinetics, thereby enhancing its ROS-disruptive efficacy. In a pursuit to further refine the targeting for acute myeloid leukemia (AML), we harnessed the maleic imide and thiol reaction mechanism, facilitating the coupling of Toll-like receptor 2 (TLR2) peptides to the liposomes' surface via maleic imide. This strategic approach offers a novel method for the precise removal of GSH, and its enhancement endeavors are directed towards fortifying the precision and efficacy of the drug's impact on AML targets.

RESULTS

We demonstrated that this peptide-liposome-small molecule machinery targets AML and consequently induces cell apoptosis both in vitro and in vivo through three disparate mechanisms: (I) Oridonin, as a Michael acceptor molecule, inhibits GSH function through covalent bonding, triggering an initial imbalance of oxidative stress. (II) Maleimide further induces GSH exhaustion, aggravating redox imbalance as a complementary augment with oridonin. (III) Peptide targets TLR2, enhances the directivity and enrichment of oridonin within AML cells.

CONCLUSION

The rationally designed nanocomplex provides a ROS drug enhancement and targeted delivery platform, representing a potential solution by disrupting redox balance for AML therapy.

Oridonin from Rabdosia rubescens: An emerging potential in cancer therapy - A comprehensive review

Cancer incidences are rising each year. In 2020, approximately 20 million new cancer cases and 10 million cancer-related deaths were recorded. The World Health Organization (WHO) predicts that by 2024 the incidence of cancer will increase to 30.2 million individuals annually. Considering the invasive characteristics of its diagnostic procedures and therapeutic methods side effects, scientists are searching for different solutions, including using plant-derived bioactive compounds, that could reduce the probability of cancer occurrence and make its treatment more comfortable. In this regard, oridonin (ORI), an ent-kaurane diterpenoid, naturally found in the leaves of Rabdosia rubescens species, has been found to have antitumor, antiangiogenesis, antiasthmatic, antiinflammatory, and apoptosis induction properties. Extensive research has been performed on ORI to find various mechanisms involved in its anticancer activities. This review article provides an overview of ORI's effectiveness on murine and human cancer populations from 1976 to 2022 and provides insight into the future application of ORI in different cancer therapies.

Emerging trends of phytochemicals as ferroptosis modulators in cancer therapy

Ferroptosis, a novel form of regulated cell death characterized by dependence on iron and lipid peroxidation, has been implicated in a wide range of clinical conditions including neurological diseases, cardiovascular disorders, acute kidney failure, and various types of cancer. Therefore, it is critical to suppress cancer progression and proliferation. Ferroptosis can be triggered in cancer cells and some normal cells by synthetic substances, such as erastin, Ras-selective lethal small molecule-3, or clinical pharmaceuticals. Natural bioactive compounds are traditional drug discovery tools, and some have been therapeutically used as dietary additives or pharmaceutical agents against various malignancies. The fact that natural products have multiple targets and minimal side effects has led to notable advances in anticancer research. Research has indicated that ferroptosis can also be induced by natural compounds during cancer treatment. In this review, we focused on the most recent developments in emerging molecular processes and the significance of ferroptosis in cancer. To provide new perspectives on the future development of ferroptosis-related anticancer medications, we also provide a summary of the implications of natural phytochemicals in triggering ferroptosis through ROS production and ferritinophagy induction in a variety of malignancies.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

New Insights on NLRP3 Inflammasome: Mechanisms of Activation, Inhibition, and Epigenetic Regulation

Inflammasomes are important modulators of inflammation. Dysregulation of inflammasomes can enhance vulnerability to conditions such as neurodegenerative diseases, autoinflammatory diseases, and metabolic disorders. Among various inflammasomes, Nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) is the best-characterized inflammasome related to inflammatory and neurodegenerative diseases. NLRP3 is an intracellular sensor that recognizes pathogen-associated molecular patterns and damage-associated patterns resulting in the assembly and activation of NLRP3 inflammasome. The NLRP3 inflammasome includes sensor NLRP3, adaptor apoptosis-associated speck-like protein (ASC), and effector cysteine protease procaspase-1 that plays an imperative role in caspase-1 stimulation which further initiates a secondary inflammatory response. Regulation of NLRP3 inflammasome ameliorates NLRP3-mediated diseases. Much effort has been invested in studying the activation, and exploration of specific inhibitors and epigenetic mechanisms controlling NLRP3 inflammasome. This review gives an overview of the established NLRP3 inflammasome assembly, its brief molecular mechanistic activations as well as a current update on specific and non-specific NLRP3 inhibitors that could be used in NLRP3-mediated diseases. We also focused on the recently discovered epigenetic mechanisms mediated by DNA methylation, histone alterations, and microRNAs in regulating the activation and expression of NLRP3 inflammasome, which has resulted in a novel method of gaining insight into the mechanisms that modulate NLRP3 inflammasome activity and introducing potential therapeutic strategies for CNS disorders.

Discovery of novel oridonin sulfamide derivatives as potent NLRP3 inhibitors by a visible-light photocatalysis-enabled peripheral editing

The progress of organicsyntheticmethod can promote late-stage lead compound modification and novel active compound discovery. Molecular editing technology in the field of organic synthesis, including peripheral and skeletal editing, facilitates rapid access to molecular diversity of a lead compound. Peripheral editing of CH bond activation is gradually used in lead optimization to afford novel active scaffolds and chemical space exploitation. To develop oridonin derivatives with high anti-inflammatory potency, novel oridonin sulfamides had been designed and synthesized by a scaffoldhopping strategy based on a visible-light photocatalysis peripheral editing. All novel compounds revealed measurable inhibition of IL-1β and low cytotoxicity in THP-1 cells. The docking study indicated that the best active compound ZM640 was accommodated in thebinding site of NLRP3 with two hydrogen bond interaction. These preliminary results confirm that α, β-unsaturated carbonyl of oridonin is not essential for NLRP3 inhibitory effect. This new oridonin scaffold has its potential to be further developed as a promising class of NLRP3 inhibitors.

The bioavailability enhancement and insight into the action mechanism of poorly soluble natural compounds from co-crystals preparation: Oridonin as an example

BACKGROUND

Natural bioactive molecules are important sources for the development of new drugs. However, most of them were limited in clinical applications due to their low aqueous solubility and bioavailability. Oridonin (ORI) is a powerful anticancer compound with above characteristics.

OBJECTIVE

This study aimed to find an effective method to improve the bioavailability of poorly soluble natural compounds, and explore the action mechanisms of them to promote their application.

RESULTS

In this study, ORI-nicotinamide (NCT) cocrystal was successfully prepared for the first time to overcome the defects of ORI. The solubility and oral bioavailability of cocrystal (COC) increased 1.34 and 1.18 times compared with ORI. Moreover, MTT assay was applied to compare the cytotoxicity of positive control drug sorafenib with ORI and COC. The IC50 values of sorafenib, ORI and COC on HepG2 cells were 7.61, 8.79 and 7.36 nmol·mL-1, which indicated that the cytotoxicity of ORI could be enhanced by cocrystal preparation. The cellular metabolomics was innovatively introduced to gain insight into the difference of cytotoxicity mechanism between ORI and COC. The results showed that there were 78 metabolites with significant differences in content between the two groups, while these differential metabolites were related to 11 metabolic pathways. Among these, glycerophospholipid metabolism and cysteine and methionine metabolism were the significant differential pathways, and the downregulation of PC(14:0/16:1(9z)) and upregulation of homocysteine were the likely main reasons for higher cytotoxicity of COC.

CONCLUSIONS

This study has presented novel approaches for enhancing the bioavailability and drug efficacy of natural compounds, while also offering fresh insights into the underlying action mechanisms of pharmaceutical cocrystals.

The Natural Product Oridonin as an Anticancer Agent: Current Achievements and Problems

Oridonin, an active diterpenoid isolated from traditional Chinese herbal medicine, has received a rising attention for its remarkable roles in cancer therapy. In recent years, increasing evidences have revealed that oridonin inhibits the occurrence and development of tumor cells through multiple mechanisms, including induction of apoptosis and autophagy, cell cycle arrest, and inhibition of angiogenesis as well as migration and invasion. In addition, several molecular signal targets have been identified, including ROS, EGFR, NF-κB, PI3K/Akt, and MAPK. In this paper, we review considerable knowledge about the molecular mechanisms and signal targets of oridonin, which has been studied in recent years. It is expected that oridonin may be developed as a novel anti-tumor herbal medicine in human cancer treatment.

Drugging the NLRP3 inflammasome: from signalling mechanisms to therapeutic targets

Diseases associated with chronic inflammation constitute a major health burden across the world. As central instigators of the inflammatory response to infection and tissue damage, inflammasomes - and the NACHT, LRR and PYD domain-containing protein 3 (NLRP3) inflammasome in particular - have emerged as key regulators in diverse rheumatic, metabolic and neurodegenerative diseases. Similarly to other inflammasome sensors, NLRP3 assembles a cytosolic innate immune complex that activates the cysteine protease caspase-1, which in turn cleaves gasdermin D (GSDMD) to induce pyroptosis, a regulated mode of lytic cell death. Pyroptosis is highly inflammatory, partly because of the concomitant extracellular release of the inflammasome-dependent cytokines IL-1β and IL-18 along with a myriad of additional danger signals and intracellular antigens. Here, we discuss how NLRP3 and downstream inflammasome effectors such as GSDMD, apoptosis-associated speck-like protein containing a CARD (ASC) and nerve injury-induced protein 1 (NINJ1) have gained significant traction as therapeutic targets. We highlight the recent progress in developing small-molecule and biologic inhibitors that are advancing into the clinic and serving to harness the broad therapeutic potential of modulating the NLRP3 inflammasome.

Oridonin suppresses the growth of glioblastoma cells via inhibiting Hippo/YAP axis

Glioma is a brain tumor that originates from brain or spine glial cells. Despite alternative treatments, the overall survival rate remains low. Oridonin (ORI) is purified from the Chinese herb Rabdosia rubescens, which has exhibited positive effects on tumors. This study aimed to investigate the effect of ORI on U87MG glioblastoma cells and whether the Hippo/YAP-related signaling pathway was involved. Malignant glioblastoma U87MG cells and male athymic nude mice (BALB/cnu/nu) were used as the experimental models. The YAP inhibitor Verteporfin (VP) and the overexpression of YAP were used to investigate its potential relation with glioma. Here, we found that ORI inhibited cell proliferation and promoted cell apoptosis in a dose-dependent manner in U87MG cells. Moreover, ORI inhibited Bcl-2, YAP, and c-Myc protein expression but increased Bax, caspase-3, and p-YAP protein expression. Furthermore, the effect of ORI was also confirmed in a mouse model bearing glioma. ORI reversed the effect of overexpression of YAP. Collectively, oridonin suppressed glioblastoma oncogenesis via the Hippo/YAP signaling pathway and could be a potential therapeutic target in the treatment of glioblastoma.

Research status of indole-modified natural products

Indole is a heterocyclic compound formed by the fusion of a benzene ring and pyrrole ring, which has rich biological activity. Many indole-containing compounds have been sold on the market due to their excellent pharmacological activity. For example, vincristine and reserpine have been widely used in clinical practice. The diverse structures and biological activities of natural products provide abundant resources for the development of new drugs. Therefore, this review classifies natural products by structure, and summarizes the research progress of indole-containing natural product derivatives, their biological activities, structure-activity relationship and research mechanism which has been studied in the past 13 years, so as to provide a basis for the development of new drug development.

Application and development of nanomaterials in the diagnosis and treatment of esophageal cancer

Esophageal cancer is a malignant tumor with a high incidence worldwide. Currently, there are a lack of effective early diagnosis and treatment methods for esophageal cancer. However, delivery systems based on nanoparticles (NPs) have shown ideal efficacy in real-time imaging and chemotherapy, radiotherapy, gene therapy, and phototherapy for tumors, which has led to their recent widespread design as novel treatment strategies. Compared to traditional drugs, nanomedicine has unique advantages, including strong targeting ability, high bioavailability, and minimal side effects. This article provides an overview of the application of NPs in the diagnosis and treatment of esophageal cancer and provides a reference for future research.

Research progress of NLRP3 inflammasome and its inhibitors with aging diseases

In recent years, a new target closely linked to a variety of diseases has appeared in the researchers' vision, which is the NLRP3 inflammasome. With the deepening of the study of NLRP3 inflammasome, it was found that it plays an extremely important role in a variety of physiological pathological processes, and NLRP3 inflammasome was also found to be associated with some age-related diseases. It is associated with the development of insulin resistance, Alzheimer's disease, Parkinson's, cardiovascular aging, hearing and vision loss. At present, the only clinical approach to the treatment of NLRP3 inflammasome-related diseases is to use anti-IL-1β antibodies, but NLRP3-specific inhibitors may be better than the IL-1β antibodies. This article reviews the relationship between NLRP3 inflammasome and aging diseases: summarizes some of the relevant experimental results reported in recent years, and introduces the biological signals or pathways closely related to the NLRP3 inflammasome in a variety of aging diseases, and also introduces some promising small molecule inhibitors of NLRP3 inflammasome for clinical treatment, such as: ZYIL1, DFV890 and OLT1177, they have excellent pharmacological effects and good pharmacokinetics.

Role of the NLRP3 inflammasome in gynecological disease

The NLR family pyrin domain containing 3 (NLRP3) inflammasome is involved in the innate immune system and is a three-part macromolecular complex comprising the NLRP3 protein, apoptosis-associated speck-like protein containing a CARD (ASC) and the cysteine protease pro-caspase-1. When the NLRP3 inflammasome is activated, it can produce interleukin (IL)- 1β and IL-18 and eventually lead to inflammatory cell pyroptosis. Related studies have demonstrated that the NLRP3 inflammasome can induce an immune response and is related to the occurrence and development of gynecological diseases, such as endometriosis, polycystic ovary syndrome and breast cancer. NLRP3 inflammasome inhibitors are beneficial for maintaining cellular homeostasis and tissue health and have been found effective in targeting some gynecological diseases. However, excessive inhibitor concentrations have been found to cause adverse effects. Therefore, proper control of NLRP3 inflammasome activity is critical. This paper summarizes the structure and function of the NLRP3 inflammasome and highlights the therapeutic potential of targeting it in gynecological diseases, such as endometriosis, polycystic ovary syndrome and breast cancer The application of NLRP3 inflammasome inhibitors is also discussed.

Integrated transcriptome, proteome and single-cell sequencing uncover the prognostic and immunological features of colony-stimulating factor 3 receptor in pan-cancer

BACKGROUND

Colony-stimulating factor 3 receptor (CSF3R) has been demonstrated to be associated with various hematological tumors, especially chronic neutrophilic leukemia; however, the detailed roles of CSF3R in other cancers remain to be explored.

METHODS

In the present study, we systematically analyzed the expression profiles of CSF3R in pan-cancer by comprehensive bioinformatics databases, such as Tumor Immune Estimation Resource, version 2 (TIMER2.0), Gene Expression Profiling Interactive Analysis, version 2 (GEPIA2.0), etc. GEPIA2.0 was also used to analyze the relationship between CSF3R expression and patients' survival prognosis.

RESULTS

We found that the high expression of CSF3R was associated with a poor prognosis in the brain tumor patients, such as brain lower grade glioma and glioblastoma multiforme. In addition, we further investigated the genetic mutation and DNA methylation level of CSF3R in multiple cancers. Immune infiltration analysis showed that CSF3R expression was positively correlated with a variety of tumor-infiltrating immune cells in most cancers. Single cell sequencing indicated that CSF3R levels were correlated with several cancer-associated pathways, such as DNA damage, cell invasion, and stemness.

CONCLUSIONS

Taken together, the role of CSF3R in multiple cancers might reveal its potential as a novel prognostic biomarker and therapeutic target for cancer patients.

NLR family pyrin domain containing 3 (NLRP3) inflammasomes and peripheral neuropathic pain - Emphasis on microRNAs (miRNAs) as important regulators

Neuropathic pain is caused by the lesion or disease of the somatosensory system and can be initiated and/or maintained by both central and peripheral mechanisms. Nerve injury leads to neuronal damage and apoptosis associated with the release of an array of pathogen- or damage-associated molecular patterns to activate inflammasomes. The activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome contributes to neuropathic pain and may represent a novel target for pain therapeutic development. In the current review, we provide an up-to-date summary of the recent findings on the involvement of NLRP3 inflammasome in modulating neuropathic pain development and maintenance, focusing on peripheral neuropathic conditions. Here we provide a detailed review of the mechanisms whereby NLRP3 inflammasomes contribute to neuropathic pain via (1) neuroinflammation, (2) apoptosis, (3) pyroptosis, (4) proinflammatory cytokine release, (5) mitochondrial dysfunction, and (6) oxidative stress. We then present the current research literature reporting on the antinociceptive effects of several natural products and pharmacological interventions that target activation, expression, and/or regulation of NLRP3 inflammasome. Furthermore, we emphasize the effects of microRNAs as another regulator of NLRP3 inflammasome. In conclusion, we summarize the possible caveats and future perspectives that might provide successful therapeutic approaches against NLRP3 inflammasome for treating or preventing neuropathic pain conditions.

Oridonin enhances cytotoxic activity of natural killer cells against lung cancer

BACKGROUND

Oridonin is a Chinese herbal medicine exhibiting anti-tumor properties; however, its immune modulation capacity has yet to be elucidated. Our objective in this study was to determine whether oridonin enhances the anti-tumor activity of natural killer (NK) cells against lung cancer cells.

METHODS

LDH-releasing assays were used to investigate the effects of oridonin on NK-92MI cell activity against lung cancer cells. Flow cytometry and real-time PCR were used to examine the effects of oridonin on degranulation markers, cytotoxic factors, activating receptors on NK-92MI cells, and ligands in lung cancer cells. Western blot analysis provided insight into the mechanisms underlying the observed effects.

RESULTS

Oridonin enhanced the cytotoxic effects of NK-92MI cells against A549 lung cancer cells. This effect involved upregulating the expression of the degranulation marker CD107a and IFN-γ as well as activating receptors on NK cells and their ligand MICA/B. Oridonin also inhibited STAT3 phosphorylation in A549 cells and NK-92MI cells. A lung cancer mouse model confirmed the anti-tumor effects of oridonin and NK-92MI cells, wherein both treatments alone suppressed tumor growth. Oridonin was also shown to have a synergistic effect on the anti-tumor activity of NK-92MI cells.

CONCLUSIONS

The ability of oridonin to enhance the cytotoxic effects of NK cells indicates its potential as a novel therapeutic agent for the treatment of lung cancer.

Improving cancer immunotherapy via co-delivering checkpoint blockade and thrombospondin-1 downregulator

The use of checkpoint-blockade antibodies is still restricted in several malignancies due to the modest efficacy, despite considerable success in anti-tumor immunotherapy. The poor response of cancer cells to immune destruction is an essential contributor to the failure of checkpoint therapy. We hypothesized that combining checkpoint therapy with natural-product chemosensitizer could enhance immune response. Herein, a targeted diterpenoid derivative was integrated with the checkpoint blockade (anti-CTLA-4) to improve immunotherapy using thermosensitive liposomes as carriers. In vivo, the liposomes enabled the co-delivery of the two drug payloads into the tumor. Consequently, the regulatory T cell proliferation was restrained, the cytotoxic T cell infiltration was enhanced, and the profound immunotherapeutic effect was achieved. In addition, the immunotherapeutic effect of another clinically used checkpoint antibody, anti-PD-1, also benefited from the diterpenoid derivative. Of note, our mechanism study revealed that the targeted diterpenoid derivative increased the sensitivity of cancer cells to immune attack via THBS1 downregulation and the resultant destruction of THBS1-CD47 interaction. Collectively, co-delivering THBS1 inhibitor and checkpoint blockade is promising to boost cancer immunotherapy. We first time discovered that THBS1 suppression could strengthen checkpoint therapy.

Oridonin impedes breast cancer growth by blocking cells in S phase and inhibiting the PI3K/AKT/mTOR signaling pathway

Breast cancer is one of the most common cancers. Oridonin, a traditional Chinese medicine, is believed to inhibit tumor growth, but its particular effects on breast cancer remain unknown. In this study, we examined oridonin's effects on 4T1, MCF-7, and MDAMB-231 cellular activity using CCK8. Scratch assays were used to detect oridonin's effects on cellular migration. Oridonin's effects on the breast cancer cell cycle were studied using flow cytometry, and expression of cell cycle related proteins p53, CDK2, and p21 was detected using Western blot assays. Metabolomics assays were used to detect changes in small molecule metabolites and metabolic pathways in breast cancer cells after treatment with oridonin. Oridonin's effects on breast cancer growth were also studied using xenograft mice. Metabolomics assays were used to detect changes in metabolites and metabolic pathways in xenograft mouse plasma in a control group, model group, and drug administration group. Experimental results showed that oridonin could significantly inhibit breast cancer growth both in vivo and in vitro. Scratch experiments showed that oridonin could inhibit breast cancer cell migration. Oridonin was also able to arrest cells in S phase by affecting several cell cycle-related proteins, including p53, CDK2, and p21. Metabolomic analysis of 4T1 cells identified a total of 33 differential metabolites, including multiple amino acids (such as l-Glutamic acid, l-Asparagine, l-Histidine, l-Valine, and l-Isoleucine). KEGG pathway enrichment analysis showed significant changes in aminoacyl-tRNA biosynthesis, and in multiple amino acid metabolic pathways. Plasma metabolomic analyses of xenograft mice revealed 28 differentially-expressed metabolites between the different animal model groups, including multiple amino acids. KEGG pathway analysis showed significant alterations in multiple amino acid metabolic pathways in oridonin-treated mice. Additionally, changes in the expression of PI3K, AKT and mTOR proteins, as well as in branched amino acids, suggest that oridonin affects the PI3K/AKT/mTOR signaling pathway by inhibiting the biosynthesis of valine, leucine and isoleucine. Taken together, our results suggest that oridonin has strong anti-tumor activity in vitro and in vivo, and has potential as an adjuvant to breast cancer treatment regimens.

Oridonin promotes endoplasmic reticulum stress via TP53-repressed TCF4 transactivation in colorectal cancer

BACKGROUND

The incidence of colorectal cancer and cancer death rate are increasing every year, and the affected population is becoming younger. Traditional Chinese medicine therapy has a unique effect in prolonging survival time and improving the prognosis of patients with colorectal cancer. Oridonin has been reported to have anti-cancer effects in a variety of tumors, but the exact mechanism remains to be investigated.

METHODS

Cell Counting Kit-8 assay (CCK8) and 5-Ethynyl-2'-deoxyuridine (EdU) staining assay, Tranwell, and Wound healing assays were performed to measure cell proliferation, invasion, and migration capacities, respectively. The protein and mRNA expression levels of various molecules were reflected by Western blot and Reverse Transcription quantitative Polymerase Chain Reaction (qRT-PCR). Transcription Factor 4 (TCF4) and its target genes were analyzed by Position Weight Matrices (PWMs) software and the Gene Expression Omnibus (GEO) database. Immunofluorescence (IF) was performed to visualize the expression and position of Endoplasmic Reticulum (ER) stress biomarkers. The morphology of the ER was demonstrated by the ER tracker-red. Reactive Oxygen Species (ROS) levels were measured using a flow cytometer (FCM) or fluorescent staining. Calcium ion (Ca²⁺) concentration was quantified by Fluo-3 AM staining. Athymic nude mice were modeled with subcutaneous xenografts.

RESULTS

Oridonin inhibited the proliferation, invasion, and migration of colorectal cancer, and this effect was weakened in a concentration-dependent manner by ER stress inhibitors. In addition, oridonin-induced colorectal tumor cells showed increased expression of ER stress biomarkers, loose morphology of ER, increased vesicles, and irregular shape. TCF4 was identified as a regulator of ER stress by PWMs software and GEO survival analysis. In vitro and in vivo experiments confirmed that TCF4 inhibited ER stress, reduced ROS production, and maintained Ca²⁺ homeostasis. In addition, oridonin also activated TP53 and inhibited TCF4 transactivation, further exacerbating the elevated ROS levels and calcium ion release in tumor cells and inhibiting tumorigenesis in colorectal cancer cells in vivo.

CONCLUSIONS

Oridonin upregulated TP53, inhibited TCF4 transactivation, and induced ER stress dysregulation in tumor cells, promoting colorectal cancer cell death. Therefore, TCF4 may be one of the important nodes for tumor cells to regulate ER stress and maintain protein synthesis homeostasis. And the inhibition of the TP53/TCF4 axis plays a key role in the anti-cancer effects of oridonin.

Signaling pathways driving ocular malignancies and their targeting by bioactive phytochemicals

Ocular cancers represent a rare pathology. The American Cancer Society estimates that 3,360 cases of ocular cancer occur annually in the United States. The major types of cancers of the eye include ocular melanoma (also known as uveal melanoma), ocular lymphoma, retinoblastoma, and squamous cell carcinoma. While uveal melanoma is one of the primary intraocular cancers with the highest occurrence in adults, retinoblastoma remains the most common primary intraocular cancer in children, and squamous cell carcinoma presents as the most common conjunctival cancer. The pathophysiology of these diseases involves specific cell signaling pathways. Oncogene mutations, tumor suppressor mutations, chromosome deletions/translocations and altered proteins are all described as causal events in developing ocular cancer. Without proper identification and treatment of these cancers, vision loss, cancer spread, and even death can occur. The current treatments for these cancers involve enucleation, radiation, excision, laser treatment, cryotherapy, immunotherapy, and chemotherapy. These treatments present a significant burden to the patient that includes a possible loss of vision and a myriad of side effects. Therefore, alternatives to traditional therapy are urgently needed. Intercepting the signaling pathways for these cancers with the use of naturally occurring phytochemicals could be a way to relieve both cancer burden and perhaps even prevent cancer occurrence. This research aims to present a comprehensive review of the signaling pathways involved in various ocular cancers, discuss current therapeutic options, and examine the potential of bioactive phytocompounds in the prevention and targeted treatment of ocular neoplasms. The current limitations, challenges, pitfalls, and future research directions are also discussed.

Integrating Computational Methods in Network Pharmacology and In Silico Screening to Uncover Multi-targeting Phytochemicals against Aberrant Protein Glycosylation in Lung Cancer

Glycoproteins are an underexploited drug target for cancer therapeutics. In this work, we integrated computational methods in network pharmacology and in silico docking approaches to identify phytochemical compounds that could potentially interact with several cancer-associated glycoproteins. We first created a database of phytochemicals from selected plant species, Manilkara zapota (sapodilla/chico), Mangifera indica (mango), Annona muricata (soursop/guyabano), Artocarpus heterophyllus (jackfruit/langka), Lansium domesticum (langsat/lanzones), and Antidesma bunius (bignay), and performed pharmacokinetic analysis to determine their drug-likeness properties. We then constructed a phytochemical-glycoprotein interaction network and characterized the degree of interactions between the phytochemical compounds and with cancer-associated glycoproteins and other glycosylation-related proteins. We found a high degree of interactions from α-pinene (Mangifera indica), cyanomaclurin (Artocarpus heterophyllus), genistein (Annona muricata), kaempferol (Annona muricata and Antidesma bunius), norartocarpetin (Artocarpus heterophyllus), quercetin (Annona muricata, Antidesma bunius, Manilkara zapota, Mangifera indica), rutin (Annona muricata, Antidesma bunius, Lansium domesticum), and ellagic acid (Antidesma bunius and Mangifera indica). Subsequent docking analysis confirmed that these compounds could potentially bind to EGFR, AKT1, KDR, MMP2, MMP9, ERBB2, IGF1R, MTOR, and HRAS proteins, which are known cancer biomarkers. In vitro cytotoxicity assays of the plant extracts showed that the n-hexane, ethyl acetate, and methanol leaf extracts from A. muricata, L. domesticum and M. indica gave the highest growth inhibitory activity against A549 lung cancer cells. These may help further explain the reported cytotoxic activities of select compounds from these plant species.

Recent advances in oridonin derivatives with anticancer activity

Cancer is a leading cause of mortality responsible for an estimated 10 million deaths worldwide in 2020, and its incidence has been rapidly growing over the last decades. Population growth and aging, as well as high systemic toxicity and chemoresistance associated with conventional anticancer therapies reflect these high levels of incidence and mortality. Thus, efforts have been made to search for novel anticancer drugs with fewer side effects and greater therapeutic effectiveness. Nature continues to be the main source of biologically active lead compounds, and diterpenoids are considered one of the most important families since many have been reported to possess anticancer properties. Oridonin is an ent-kaurane tetracyclic diterpenoid isolated from Rabdosia rubescens and has been a target of extensive research over the last few years. It displays a broad range of biological effects including neuroprotective, anti-inflammatory, and anticancer activity against a variety of tumor cells. Several structural modifications on the oridonin and biological evaluation of its derivatives have been performed, creating a library of compounds with improved pharmacological activities. This mini-review aims to highlight the recent advances in oridonin derivatives as potential anticancer drugs, while succinctly exploring their proposed mechanisms of action. To wind up, future research perspectives in this field are also disclosed.

Oridonin Induces Apoptosis in Esophageal Squamous Cell Carcinoma by Inhibiting Cytoskeletal Protein LASP1 and PDLIM1

Esophageal squamous cell carcinoma is a severe malignancy for its high mortality and poor prognosis. Mainstay chemotherapies cause serious side effects for their ways of inducing cell death. Oridonin is the main bioactive constituent from natural plants that has anticancer ability and weak side effects. The proteomics method is efficient to understand the anticancer mechanism. However, proteins identified by proteomics aimed at understanding oridonin's anticancer mechanism is seldom overlapped by different groups. This study used proteomics based on two-dimensional electrophoresis sodium dodecyl sulfate-polyacrylamide gel electrophoresis (2-DE SDS-PAGE) integrated with mass spectrometry and Gene Set Enrichment Analysis (GSEA) to understand the anticancer mechanism of oridonin on esophageal squamous cell carcinoma (ESCC). The results showed that oridonin induced ESCC cell death via apoptosis by decreasing the protein expression of LASP1 and PDLIM1.

Unraveling the significance of exosomal circRNAs in cancer therapeutic resistance

Exosomes are nanoscale extracellular vesicles secreted by a variety of cells, affecting the physiological and pathological homeostasis. They carry various cargoes including proteins, lipids, DNA, and RNA and have emerged as critical mediators of intercellular communication. During cell-cell communication, they can internalize either by autologous or heterologous recipient cells, which activate different signaling pathways, facilitating malignant progression of cancer. Among different types of cargoes in exosomes, the endogenous non-coding RNAs, such as circular RNAs (or circRNAs), have gained tremendous attention for their high stability and concentration, playing promising functional roles in cancer chemotherapeutic response by regulating the targeted gene expression. In this review, we primarily described the emerging evidence demonstrating the important roles of circular RNAs derived from exosomes in the regulation of cancer-associated signaling pathways that were involved in cancer research and therapeutic interventions. Additionally, the relevant profiles of exosomal circRNAs and their biological implications have been discussed, which is under investigation for their potential effect on the control of cancer therapeutic resistance.

Oridonin ameliorates acetaminophen-induced acute liver injury through ATF4/PGC-1α pathway

Acetaminophen (APAP) overdose-induced acute liver injury (ALI) causes hepatocyte cell death, oxidative stress, and inflammation. Oridonin (Ori), a covalent NLRP3-inflammasome inhibitor, ameliorates APAP-induced ALI through an unclear molecular mechanism. This study found that Ori decreased hepatic cytochrome P450 2E1 level and increased glutathione content to prevent APAP metabolism, and then reduced the necrotic area, improved liver function, and inhibited APAP-induced proinflammatory cytokines and oxidative stress. Ori also decreased activating transcription factor 4 (ATF4) protein levels and increased peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) to reduce APAP-induced endoplasmic reticulum stress activation and mitochondrial dysfunction. Furthermore, western blot and luciferase assay found that ATF4 inhibited transcription in the PGC-1α promoter -507 to -495 region to reduce PGC-1α levels, while ATF4 knockdown neutralized the hepatoprotective effect of Ori. Molecular docking showed that Ori bound to ATF4's amino acid residue glutamate 302 through 6, 7, and 18 hydroxyl bands. Our findings demonstrated that Ori prevented metabolic activation of APAP and further inhibited the ATF4/PGC-1α pathway to alleviate APAP overdose-induced hepatic toxicity, which illuminated its potential therapeutic effects on ALI.

Dearomative logic in natural product total synthesis

Covering: 2011 to 2022The natural world is a prolific source of some of the most interesting, rare, and complex molecules known, harnessing sophisticated biosynthetic machinery evolved over billions of years for their production. Many of these natural products represent high-value targets of total synthesis, either for their desirable biological activities or for their beautiful structures outright; yet, the high sp3-character often present in nature's molecules imparts significant topological complexity that pushes the limits of contemporary synthetic technology. Dearomatization is a foundational strategy for generating such intricacy from simple materials that has undergone considerable maturation in recent years. This review highlights the recent achievements in the field of dearomative methodology, with a focus on natural product total synthesis and retrosynthetic analysis. Disconnection guidelines and a three-phase dearomative logic are described, and a spotlight is given to nature's use of dearomatization in the biosynthesis of various classes of natural products. Synthetic studies from 2011 to 2021 are reviewed, and 425 references are cited.

Recent advances in the pharmacological targeting of ubiquitin-regulating enzymes in cancer

As a post-translational modification that has pivotal roles in protein degradation, ubiquitination ensures that intracellular proteins act in a precise spatial and temporal manner to regulate diversified cellular processes. Perturbation of the ubiquitin system contributes directly to the onset and progression of a wide variety of diseases, including various subtypes of cancer. This highly regulated system has been for years an active research area for drug discovery that is exemplified by several approved drugs. In this review, we will provide an update of the main breakthrough scientific discoveries that have been leading the clinical development of ubiquitin-targeting therapies in the last decade, with a special focus on E1 and E3 modulators. We will further discuss the unique challenges of identifying new potential therapeutic targets within this ubiquitous and highly complex machinery, based on available crystallographic structures, and explore chemical approaches by which these challenges might be met.

Selected Phytochemicals to Combat Lungs Injury: Natural Care

The human has two lungs responsible for respiration and drug metabolism. Severe lung infection caused by bacteria, mycobacteria, viruses, fungi, and parasites may lead to lungs injury. Smoking and tobacco consumption may also produce lungs injury. Inflammatory and pain mediators are secreted by alveolar macrophages. The inflammatory mediators, such as cytokines, interleukin (IL)-1, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α, neutrophils, and fibroblasts are accumulated in the alveoli sac, which becomes infected. It may lead to hypoxia followed by severe pulmonary congestion and the death of the patient. There is an urgent need for the treatment of artificial respiration and ventilation. However, the situation may be the worst for patients suffering from lung cancer, pulmonary tuberculosis, and acute pneumonia caused by acute respiratory distress syndrome (ARDS). Re-urgency has been happening in the case of coronavirus disease of 2019 (COVID-19) patients. Therefore, it is needed to protect the lungs with the intake of natural phytomedicines. In the present review, several selected phyto components having the potential role in lung injury therapy have been discussed. Regular intake of natural vegetables and fruits bearing these constituents may save the lungs even in the dangerous attack of SARS-CoV-2 in lung cancer, pulmonary TB, and pneumatic patients.

Impairment of Nucleolin Activity and Phosphorylation by a Trachylobane Diterpene from Psiadia punctulata in Cancer Cells

Human nucleolin (hNcl) is a multifunctional protein involved in the progression of various cancers and plays a key role in other pathologies. Therefore, there is still unsatisfied demand for hNcl modulators. Recently, we demonstrated that the plant ent-kaurane diterpene oridonin inhibits hNcl but, unfortunately, this compound is quite toxic for healthy cells. Trachylobane diterpene 6,19-dihydroxy-ent-trachiloban-17-oic acid (compound 12) extracted from Psiadia punctulata (DC.) Vatke (Asteraceae) emerged as a ligand of hNcl from a cellular thermal shift assay (CETSA)-based screening of a small library of diterpenes. Effective interaction between this compound and the protein was demonstrated to occur both in vitro and inside two different types of cancer cells. Based on the experimental and computational data, a model of the hNcl/compound 12 complex was built. Because of this binding, hNcl mRNA chaperone activity was significantly reduced, and the level of phosphorylation of the protein was affected. At the biological level, cancer cell incubation with compound 12 produced a cell cycle block in the subG0/G1 phase and induced early apoptosis, whereas no cytotoxicity towards healthy cells was observed. Overall, these results suggested that 6,19-dihydroxy-ent-trachiloban-17-oic could represent a selective antitumoral agent and a promising lead for designing innovative hNcl inhibitors also usable for therapeutic purposes.

Spirolactone-type and enmein-type derivatives as potential anti-cancer agents derived from oridonin

Natural products (NPs) are always the important sources in the field of drug discovery, among which spirolactone-type and enmein-type compounds exhibit a wide range of biological activities, especially anti-tumor activity. Based on previous studies, the spirolactone-type and enmein-type compounds could be derived from natural oridonin (1) by several chemical reactions. Herein, a series of novel spirolactone-type and enmein-type derivatives with different aryl allyl ester substitutions at their C-14 hydroxyl group were designed and synthesized. The anti-tumor activity results showed that most of the compounds exhibited better anti-proliferative activities than parent compound oridonin, and the most potent compound had an IC₅₀ value of 0.40 μM in K562 cells. Further mechanistic studies revealed that the optimal compound could arrest K562 cells at G2/M phase by inhibiting cdc-2, cdc-25c and cyclin B1 expression. In addition, the optimal compound induced apoptosis in K562 cells through increasing ROS production and depolarizing mitochondrial membrane potential. Collectively, these valuable results suggested that the most potent compound could be an anti-tumor agent candidate and is worthy of further investigation.

Traditional Medicinal Plants as a Source of Inspiration for Osteosarcoma Therapy

Osteosarcoma is one of the most common types of bone cancers among paediatric patients. Despite the advances made in surgery, chemo-, and radiotherapy, the mortality rate of metastatic osteosarcoma remains unchangeably high. The standard drug combination used to treat this bone cancer has remained the same for the last 20 years, and it produces many dangerous side effects. Through history, from ancient to modern times, nature has been a remarkable source of chemical diversity, used to alleviate human disease. The application of modern scientific technology to the study of natural products has identified many specific molecules with anti-cancer properties. This review describes the latest discovered anti-cancer compounds extracted from traditional medicinal plants, with a focus on osteosarcoma research, and on their cellular and molecular mechanisms of action. The presented compounds have proven to kill osteosarcoma cells by interfering with different pathways: apoptosis induction, stimulation of autophagy, generation of reactive oxygen species, etc. This wide variety of cellular targets confer natural products the potential to be used as chemotherapeutic drugs, and also the ability to act as sensitizers in drug combination treatments. The major hindrance for these molecules is low bioavailability. A problem that may be solved by chemical modification or nano-encapsulation.

Targeting autophagy and neuroinflammation pathways with plant-derived natural compounds as potential antidepressant agents

Major depressive disorder (MDD) is a life-threatening disease that presents several characteristics. The pathogenesis of depression still remains poorly understood. Moreover, the mechanistic interactions of natural components in treating depression to target autophagy and neuroinflammation are yet to be evaluated. This study overviewed the effects of plant-derived natural components in regulating critical pathways, particularly neuroinflammation and autophagy, associated with depression. A list of natural components, including luteolin, apigenin, hyperforin, resveratrol, salvianolic acid b, isoliquiritin, nobiletin, andrographolide, and oridonin, have been investigated. All peer-reviewed journal articles were searched by Scopus, MEDLINE, PubMed, Web of Science, and Google Scholar using the appropriated keywords, including depression, neuroinflammation, autophagy, plant, natural components, etc. The neuroinflammation and autophagy dysfunction are critically associated with the pathophysiology of depression. Natural components with higher efficiency and lower complications can be used for targeting neuroinflammation and autophagy. These components with different doses showed the beneficial antidepressant properties in rodents. These can modulate autophagy markers, mainly AMPK, LC3II/LC3I ratio, Beclin-1. Moreover, they can regulate the NLRP3 inflammasome, resulting in the suppression of proinflammatory cytokines (e.g., IL-1β and IL-18). Future in vitro and in vivo studies are required to develop novel therapeutic approaches based on plant-derived active components to treat MDD.

Phytochemicals for the Prevention and Treatment of Renal Cell Carcinoma: Preclinical and Clinical Evidence and Molecular Mechanisms

Renal cell carcinoma (RCC) is associated with about 90% of renal malignancies, and its incidence is increasing globally. Plant-derived compounds have gained significant attention in the scientific community for their preventative and therapeutic effects on cancer. To evaluate the anticancer potential of phytocompounds for RCC, we compiled a comprehensive and systematic review of the available literature. Our work was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. The literature search was performed using scholarly databases such as PubMed, Scopus, and ScienceDirect and keywords such as renal cell carcinoma, phytochemicals, cancer, tumor, proliferation, apoptosis, prevention, treatment, in vitro, in vivo, and clinical studies. Based on in vitro results, various phytochemicals, such as phenolics, terpenoids, alkaloids, and sulfur-containing compounds, suppressed cell viability, proliferation and growth, showed cytotoxic activity, inhibited invasion and migration, and enhanced the efficacy of chemotherapeutic drugs in RCC. In various animal tumor models, phytochemicals suppressed renal tumor growth, reduced tumor size, and hindered angiogenesis and metastasis. The relevant antineoplastic mechanisms involved upregulation of caspases, reduction in cyclin activity, induction of cell cycle arrest and apoptosis via modulation of a plethora of cell signaling pathways. Clinical studies demonstrated a reduced risk for the development of kidney cancer and enhancement of the efficacy of chemotherapeutic drugs. Both preclinical and clinical studies displayed significant promise of utilizing phytochemicals for the prevention and treatment of RCC. Further research, confirming the mechanisms and regulatory pathways, along with randomized controlled trials, are needed to establish the use of phytochemicals in clinical practice.