Artemisinin and Its Derivatives as a Repurposing Anticancer Agent: What Else Do We Need to Do?

A Highly Selective and Versatile Probe Platform for Visualization of Monoacylglycerol Lipase

Monoacylglycerol lipase (MAGL) is a key enzyme for signal termination in the endocannabinoid system (ECS). MAGL inhibition results in indirect activation of the cannabinoid receptors, which offers unique advantages for the treatment of, e.g., multiple sclerosis, epilepsy, and other neurological disorders. Molecular imaging techniques are valuable tools to overcome the current poor understanding of MAGL's distribution and role in patho- and physiological processes within ECS signaling. Herein, we report the design, synthesis, and validation of highly selective versatile fluorescent and click-chemistry probes for MAGL. Structure-based design combined with a reverse-design approach allowed the development of a structural unit that selectively and effectively recognizes MAGL while offering a versatile platform to attach different fluorophores and further reporter units. In this way, labeled probes with sub-nanomolar potency carrying diverse fluorescent dyes were obtained. Probe affinity and selectivity remained invariant to changes in the fluorophore subunit, showing the remarkable robustness of this platform in delivering tailor-made probes. Highly consistent inhibition across species supports pharmacological model translatability. Extensive profiling and validation in various cellular systems shows the ability of these highly potent and selective probes to elucidate the complex role of MAGL in ECS cellular signaling, inflammatory processes, and disease progression.

Targeting ferroptosis in gastrointestinal tumors: Interplay of iron-dependent cell death and autophagy

Ferroptosis is a regulated cell death mechanism distinct from apoptosis, autophagy, and necroptosis, marked by iron accumulation and lipid peroxidation. Since its identification in 2012, it has developed into a potential therapeutic target, especially concerning GI disorders like PC, HCC, GC, and CRC. This interest arises from the distinctive role of ferroptosis in the progression of diseases, presenting a new avenue for treatment where existing therapies fall short. Recent studies emphasize the promise of focusing on ferroptosis to fight GI cancers, showcasing its unique pathophysiological mechanisms compared to other types of cell death. By comprehending how ferroptosis aids in the onset and advancement of GI diseases, scientists aim to discover novel drug targets and treatment approaches. Investigating ferroptosis in gastrointestinal disorders reveals exciting possibilities for novel therapies, potentially revolutionizing cancer treatment and providing renewed hope for individuals affected by these tumors.

Design, synthesis, and in vitro and in vivo biological evaluation of dihydroartemisinin derivatives as potent anti-cancer agents with ferroptosis-inducing and apoptosis-activating properties

Natural products play a pivotal role in drug development, including their direct use as pharmaceuticals and their structural modification, yielding molecules with enhanced therapeutic potential. The discovery of bioactive molecules, lead compounds, and novel drugs is intrinsically linked to the structural optimization of natural products. In this study, forty-one derivatives of dihydroartemisinin (DHA) were synthesized by incorporating fragments with anti-tumour activity via molecular hybridization, and assessed for their anti-proliferative activity against human cancer cell lines (A549, Bel-7402, HCT-116, and SW620) and normal human liver cells (LO2). Most derivatives exhibited superior anti-proliferative activity compared to DHA. Notably, compound A3, featuring a 4-Cl phenyl carbamate moiety, demonstrated significant anti-proliferative activity against HCT-116 cells with an IC50 of 0.31 μM, making it 16-fold more potent than DHA (IC50 = 5.10 μM). The anti-proliferative mechanism did not involve cytotoxicity (SI = 54.13), indicating its superior safety profile compared to DHA (SI = 1.65). Further mechanistic studies revealed that compound A3 inhibits HCT-116 cell proliferation by modulating the expression of PI3K/AKT/mTOR and STAT3 proteins. STAT3 downregulation represses the expression of the critical ferroptosis protein glutathione peroxidase 4 (GPX4), aggravating the accumulation of reactive oxygen species (ROS) and depletion of glutathione (GSH). This redox imbalance triggers and accelerates ferroptosis. Additionally, A3 also induces apoptosis by damaging mitochondria and influencing MAPK signaling. Compound A3 arrested cells in the G2/M phase by regulating p53 expression. In an HCT-116 xenograft mouse model, compound A3 exhibited significant anti-cancer efficacy, with a tumor growth inhibition rate of 58.7 %. Therefore, compound A3 thus has the potential to serve as a lead compound for the development of new anti-tumor drugs.

Drug Repurposing for Cancer Treatment: A Comprehensive Review

Cancer ranks among the primary contributors to global mortality. In 2022, the global incidence of new cancer cases reached about 20 million, while the number of cancer-related fatalities reached 9.7 million. In Saudi Arabia, there were 13,399 deaths caused by cancer and 28,113 newly diagnosed cases of cancer. Drug repurposing is a drug discovery strategy that has gained special attention and implementation to enhance the process of drug development due to its time- and money-saving effect. It involves repositioning existing medications to new clinical applications. Cancer treatment is a therapeutic area where drug repurposing has shown the most prominent impact. This review presents a compilation of medications that have been repurposed for the treatment of various types of cancers. It describes the initial therapeutic and pharmacological classes of the repurposed drugs and their new applications and mechanisms of action in cancer treatment. The review reports on drugs from various pharmacological classes that have been successfully repurposed for cancer treatment, including approved ones and those in clinical trials and preclinical development. It stratifies drugs based on their anticancer repurpose as multi-type, type-specific, and mechanism-directed, and according to their pharmacological classes. The review also reflects on the future potential that drug repurposing has in the clinical development of novel anticancer therapies.

11-Azaartemisinin derivatives bearing halogenated aromatic moieties: Potent anticancer agents with high tumor selectivity

While artemisinin and its derivatives, including 11-azaartemisinin-based compounds, have shown promising anticancer activity, the integration of halogens into aromatic structures can amplify drug potency, metabolic stability, and selectivity. Herein, we present the synthesis of new novel 11-azaartemisinin derivatives bearing halogenated aromatic moieties connected via 1,2,3-triazole bridges and evaluate their anticancer activities against three human tumor cell lines: epidermoid carcinoma (KB), hepatocellular carcinoma (HepG2), and human lung adenocarcinoma (A549). Among the synthesized compounds, six of them (8c-h) displayed good to excellent antiproliferative activity in the low micromolar range across all three human cancer cell lines. In general, the m-bromide (8c) and m-iodide (8d) compounds exhibited superior anticancer activities compared to their o- and p-analogs, as well as the m-chloride and m-fluoride compounds. The most promising m-Br compound (8c) displayed 50 % inhibition of KB, HepG2, and A549 cell growth at concentrations of 7.7, 42.5, and 15.5 μM, respectively. Notably, the m-Br compound (8c) exhibited approximately 32-, 6-, and 16-fold lower activity in normal cells (Hek293) compared to KB, HepG2, and A549 tumor cells, respectively, indicating a significant tumor-selectivity.

High-Altitude Medicinal Plants as Promising Source of Phytochemical Antioxidants to Combat Lifestyle-Associated Oxidative Stress-Induced Disorders

Oxidative stress, driven by reactive oxygen, nitrogen, and sulphur species (ROS, RNS, RSS), poses a significant threat to cellular integrity and human health. Generated during mitochondrial respiration, inflammation, UV exposure and pollution, these species damage cells and contribute to pathologies like cardiovascular issues, neurodegeneration, cancer, and metabolic syndromes. Lifestyle factors exert a substantial influence on oxidative stress levels, with mitochondria emerging as pivotal players in ROS generation and cellular equilibrium. Phytochemicals, abundant in plants, such as carotenoids, ascorbic acid, tocopherols and polyphenols, offer diverse antioxidant mechanisms. They scavenge free radicals, chelate metal ions, and modulate cellular signalling pathways to mitigate oxidative damage. Furthermore, plants thriving in high-altitude regions are adapted to extreme conditions, and synthesize secondary metabolites, like flavonoids and phenolic compounds in bulk quantities, which act to form a robust antioxidant defence against oxidative stress, including UV radiation and temperature fluctuations. These plants are promising sources for drug development, offering innovative strategies by which to manage oxidative stress-related ailments and enhance human health. Understanding and harnessing the antioxidant potential of phytochemicals from high-altitude plants represent crucial steps in combating oxidative stress-induced disorders and promoting overall wellbeing. This study offers a comprehensive summary of the production and physio-pathological aspects of lifestyle-induced oxidative stress disorders and explores the potential of phytochemicals as promising antioxidants. Additionally, it presents an appraisal of high-altitude medicinal plants as significant sources of antioxidants, highlighting their potential for drug development and the creation of innovative antioxidant therapeutic approaches.

Tween 80 Micelles Loaded with Fe3O4 Nanoparticles and Artemisinin for Combined Oxygen-Independent Ferroptosis Therapy of Cancer

Artemisinin has an endoperoxide bridge structure, which can be cleaved by ferrous ions to generate various carbonyl radicals in an oxygen-independent manner, highlighting its potential for treating hypoxic tumors. In our study, we fabricated Tween 80 micelles loaded with Fe3O4 nanoparticles and artemisinin for cancer therapy. The synthesized Fe3O4 nanoparticles and drug-loaded micelles have particle sizes of about 5 nm and 80 nm, respectively, both exhibiting excellent dispersibility and stability. After uptake by MCF-7 cells, drug-loaded micelles release Fe2+ and ART into the cytoplasm, effectively inducing the generation of reactive oxygen species (ROS) in hypoxic conditions, thereby enhancing toxicity against cancer cells. In vitro and in vivo studies have demonstrated that ART and Fe3O4 nanoparticles are encapsulated in Tween 80 to form micelles, which effectively prevent premature release during circulation in the body. Although free ART and Fe3O4 nanoparticles can inhibit tumor growth, TW80-Fe3O4-ART micelles demonstrate a more pronounced inhibitory effect, with a tumor suppression rate of up to 85%. A novel strategy based on artemisinin and ferroptosis is thus offered, holding a favorable prospect for hypoxic cancer therapy.

Targeting ferroptosis for leukemia therapy: exploring novel strategies from its mechanisms and role in leukemia based on nanotechnology

The latest findings in iron metabolism and the newly uncovered process of ferroptosis have paved the way for new potential strategies in anti-leukemia treatments. In the current project, we reviewed and summarized the current role of nanomedicine in the treatment and diagnosis of leukemia through a comparison made between traditional approaches applied in the treatment and diagnosis of leukemia via the existing investigations about the ferroptosis molecular mechanisms involved in various anti-tumor treatments. The application of nanotechnology and other novel technologies may provide a new direction in ferroptosis-driven leukemia therapies. The article explores the potential of targeting ferroptosis, a new form of regulated cell death, as a new therapeutic strategy for leukemia. It discusses the mechanisms of ferroptosis and its role in leukemia and how nanotechnology can enhance the delivery and efficacy of ferroptosis-inducing agents. The article not only highlights the promise of ferroptosis-targeted therapies and nanotechnology in revolutionizing leukemia treatment, but also calls for further research to overcome challenges and fully realize the clinical potential of this innovative approach. Finally, it discusses the challenges and opportunities in clinical applications of ferroptosis.

Recent advances in the synthesis and antimalarial activity of 1,2,4-trioxanes

The increasing resistance of various malarial parasite strains to drugs has made the production of a new, rapid-acting, and efficient antimalarial drug more necessary, as the demand for such drugs is growing rapidly. As a major global health concern, various methods have been implemented to address the problem of drug resistance, including the hybrid drug concept, combination therapy, the development of analogues of existing medicines, and the use of drug resistance reversal agents. Artemisinin and its derivatives are currently used against multidrug- resistant P. falciparum species. However, due to its natural origin, its use has been limited by its scarcity in natural resources. As a result, finding a substitute becomes more crucial, and the peroxide group in artemisinin, responsible for the drugs biological action in the form of 1,2,4-trioxane, may hold the key to resolving this issue. The literature suggests that 1,2,4-trioxanes have the potential to become an alternative to current malaria drugs, as highlighted in this review. This is why 1,2,4-trioxanes and their derivatives have been synthesized on a large scale worldwide, as they have shown promising antimalarial activity in vivo and in vitro against Plasmodium species. Consequently, the search for a more convenient, environment friendly, sustainable, efficient, and effective synthetic pathway for the synthesis of 1,2,4-trioxanes continues. The aim of this work is to provide a comprehensive analysis of the synthesis and mechanism of action of 1,2,4-trioxanes. This systematic review highlights the most recent summaries of derivatives of 1,2,4-trioxane compounds and dimers with potential antimalarial activity from January 1988 to 2023.

Targeting Inhibition of Accumulation and Function of Myeloid-Derived Suppressor Cells by Artemisinin via PI3K/AKT, mTOR, and MAPK Pathways Enhances Anti-PD-L1 Immunotherapy in Melanoma and Liver Tumors

Despite the remarkable success and efficacy of immune checkpoint blockade (ICB) therapy such as anti-PD-L1 antibody in treating cancers, myeloid-derived suppressor cells (MDSCs) that lead to the formation of the protumor immunosuppressive microenvironment are one of the major contributors to ICB resistance. Therefore, inhibition of MDSC accumulation and function is critical for further enhancing the therapeutic efficacy of anti-PD-L1 antibody in a majority of cancer patients. Artemisinin (ART), the most effective antimalarial drug with tumoricidal and immunoregulatory activities, is a potential option for cancer treatment. Although ART is reported to reduce MDSC levels in 4T1 breast tumor model and improve the therapeutic efficacy of anti-PD-L1 antibody in T cell lymphoma-bearing mice, how ART influences MDSC accumulation, function, and molecular pathways as well as MDSC-mediated anti-PD-L1 resistance in melanoma or liver tumors remains unknown. Here, we reported that ART blocks the accumulation and function of MDSCs by polarizing M2-like tumor-promoting phenotype towards M1-like antitumor one. This switch is regulated via PI3K/AKT, mTOR, and MAPK signaling pathways. Targeting MDSCs by ART could significantly reduce tumor growth in various mouse models. More importantly, the ART therapy remarkably enhanced the efficacy of anti-PD-L1 immunotherapy in tumor-bearing mice through promoting antitumor T cell infiltration and proliferation. These findings indicate that ART controls the functional polarization of MDSCs and targeting MDSCs by ART provides a novel therapeutic strategy to enhance anti-PD-L1 cancer immunotherapy.

Inactivation of PDH can Reduce Anaplastic Thyroid Cancer Cells' Sensitivity to Artemisinin

BACKGROUND

Anaplastic Thyroid Cancer (ATC) is a rare subtype of thyroid tumors with a high mortality rate. Targeted therapies against ATC are ineffective and mostly transient. Artemisinin has shown excellent anti-tumor activity in several cancers, but its effects on ATC are still unknown.

OBJECTIVE

To evaluate the effects of artemisinin on ATC cells and assess the mechanism underlying drug resistance.

METHODS

The viability and proliferation rates of the artemisinin-treated CAL-62 and BHT-101 cells were analyzed by MTT and EdU incorporation assays. The protein expression levels were determined by Tandem Mass Tag (TMT) labeling quantitative proteomics and western blotting.

RESULTS

Artemisinin treatment significantly decreased the expression levels of COX2 and COX7A2 and increased that of COX14, YEM1l1, ALAS1, and OAT after 48h. In addition, FTL was upregulated in the CAL-62 cells and downregulated in BHT-101 cells. The CAL-62 cells showed transient and reversible resistance to artemisinin, which was correlated to time-dependent changes in HIF1α, PDK1, and PDHA levels.

CONCLUSION

Artemisinin targets the mitochondrial respiratory chain proteins in ATC cells. CAL-62 cells show transient resistance to artemisinin via PDH downregulation, indicating that PDH activation may enhance the cytotoxic effects of artemisinin on ATC cells.

Drug Repurposing Strategies for Non-Cancer to Cancer Therapeutics

Global efforts invested for the prevention and treatment of cancer need to be repositioned to develop safe, effective, and economic anticancer therapeutics by adopting rational approaches of drug discovery. Drug repurposing is one of the established approaches to reposition old, clinically approved off patent noncancer drugs with known targets into newer indications. The literature review suggests key role of drug repurposing in the development of drugs intended for cancer as well as noncancer therapeutics. A wide category of noncancer drugs namely, drugs acting on CNS, anthelmintics, cardiovascular drugs, antimalarial drugs, anti-inflammatory drugs have come out with interesting outcomes during preclinical and clinical phases. In the present article a comprehensive overview of the current scenario of drug repurposing for the treatment of cancer has been focused. The details of some successful studies along with examples have been included followed by associated challenges.

Induction and application of ferroptosis in cancer therapy

At present, more than one cell death pathways have been found, one of which is ferroptosis. Ferroptosis was discovered in 2012 and described as an iron-dependent and lipid peroxidation-driven regulated cell death pathway. In the past few years, ferroptosis has been shown to induce tumor cell death, providing new ideas for tumor treatment. In this article, we summarize the latest advances in ferroptosis-induced tumor therapy at the intersection of tumor biology, molecular biology, redox biology, and materials chemistry. First, we state the characteristics of ferroptosis in cells, then introduce the key molecular mechanism of ferroptosis, and describes the relationship between ferroptosis and oxidative stress signaling pathways. Finally, we focused on several types of ferroptosis inducers discovered by scholars, and the application of ferroptosis in systemic chemotherapy, radiotherapy, immunotherapy and nanomedicine, in the hope that ferroptosis can exert its potential in the treatment of tumors.

Artemisia annua Growing Wild in Romania—A Metabolite Profile Approach to Target a Drug Delivery System Based on Magnetite Nanoparticles

The metabolites profile of a plant is greatly influenced by geographical factors and the ecological environment. Various studies focused on artemisinin and its derivates for their antiparasitic and antitumoral effects. However, after the isolation and purification stage, their pharmaceutical potential is limited due to their low bioavailability, permeability and lifetime. The antibacterial activity of essential oils has been another topic of interest for many studies on this plant. Nevertheless, only a few studies investigate other metabolites in Artemisia annua. Considering that secondary metabolites act synergistically in a plant, the existence of other metabolites with antitumor and high immunomodulating activity is even more important. Novel nano-carrier systems obtained by loading herbs into magnetic nanoparticles ensures the increase in the antitumor effect, but also, overcoming the barriers related to permeability, localization. This study reported the first complete metabolic profile from wild grown Romanian Artemisia annua. A total of 103 metabolites were identified under mass spectra (MS) positive mode from 13 secondary metabolite categories: amino acids, terpenoids, steroids, coumarins, flavonoids, organic acids, fatty acids, phenolic acids, carbohydrates, glycosides, aldehydes, hydrocarbons, etc. In addition, the biological activity of each class of metabolites was discussed. We further developed a simple and inexpensive nano-carrier system with the intention to capitalize on the beneficial properties of both components. Evaluation of the nano-carrier system’s morpho-structural and magnetic properties was performed.

Immunomolecular evaluation of dihydroartemisinin effects on apoptosis in chronic lymphocytic leukemia cell lines

INTRODUCTION

Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has recently shown to induce apoptosis in many types of cancer cells. In this study, we aimed to determine the effects of DHA on apoptosis in human chronic lymphocytic leukemia (CLL) cell lines.

METHODS

The cells were treated separately and combined by DHA and Fludurabine (FLU) during 24, 48 and 72 hours. The cell viabilities determined by XTT method. Following separate and combined treatment of IC50 concentrations of DHA and FLU to the cells during 24 hours, the cells were analyzed by flow cytometry to determine the effects on apopotis staining with AnnexinV FITC and PI. mRNA and protein expression levels of TCTP, Mcl-1, Bcl-2, Bax and Caspase-3 were analyzed to find out the molecular mechanisms of apoptosis by using quantitative real-time PCR and flow cytometric methods.

RESULTS

Treatment with DHA alone or in combination with FLU induced apoptosis in a dose dependent manner in CLL cells. DHA alone was more effective than FLU alone or combined treatment with DHA and FLU. Our results suggest that Bcl-2 protein family member Bax was active in the apoptotic response of CLL cells after DHA treatment. Moreover, the apoptotic response induced by DHA was independent from the p53 mutation status of the CLL cells.

CONCLUSION

DHA might be a potential anti-cancer therapeutic for CLL.

(-)-6-epi-Artemisinin, a Natural Stereoisomer of (+)-Artemisinin in the Opposite Enantiomeric Series, from the Endemic Madagascar Plant Saldinia proboscidea, an Atypical Source

Chemical and biological investigation of the Madagascar endemic plant Saldinia proboscidea led to the isolation of an isomer of artemisinin, (-)-6-epi-artemisinin (2). Its structure was elucidated using a combination of NMR and mass spectrometry. The absolute configuration was established by chemical syntheses of compound 2 as well as a new stereoisomer (3). The comparable bioactivities of artemisinin (1) and its isomer (-)-6-epi-artemisinin (2) revealed that this change in configuration was not critical to their biological properties. Bioactivity was assessed using an apoptosis induction assay, a SARS-CoV-2 inhibitor assay, and a haematin polymerization inhibitory activity (HPIA) assay. This is the first report of an artemisinin-related compound from a genus not belonging to Artemisia and it is the first isolation of an artemisinin-related natural product that is the opposite enantiomeric series relative to artemisinin from Artemisia annua.

Chemical Constituents and their Anti-Tumor Mechanism of Plants from Artemisia

BACKGROUND

At present, chemotherapy is still the main treatment method for cancer, but its side effects and multidrug resistance limit the therapeutic effect seriously. Now the screening of anti-tumor drugs with higher efficiency and lower toxicity from natural products is one of the important research directions for oncotherapy. Artemisia has a variety of anti-tumor constituents, which can exert its anti-tumor effect by inducing tumor cell apoptosis, inhibiting tumor angiogenesis, arresting cell cycle, accelerating iron ion-mediated oxidative damage, etc. Objective: This paper will provide a focused, up-to-date and comprehensive overview of the anti-tumor active constituents and their mechanisms of plants in Artemisia.

METHOD

The relevant information about Artemisia and its bioactive components comes from scientific databases (such as PubMed, Web of Science, Science Direct).

RESULTS

Here we have discussed the present situation and mechanism of bioactive components of Artemisia in anti-tumor. The application prospect of active components of Artemisia in cancer prevention and treatment was investigated.

CONCLUSION

The information summarized in this review may provide new ideas for the follow-up treatment of cancer and contribute to the development of new, effective, multi-side effects and fewer side effects of antineoplastic drugs.

Geminal Diheteroatomic Motifs: Some Applications of Acetals, Ketals, and Their Sulfur and Nitrogen Homologues in Medicinal Chemistry and Drug Design

Acetals and ketals and their nitrogen and sulfur homologues are often considered to be unconventional and potentially problematic scaffolding elements or pharmacophores for the design of orally bioavailable drugs. This opinion is largely a function of the perception that such motifs might be chemically unstable under the acidic conditions of the stomach and upper gastrointestinal tract. However, even simple acetals and ketals, including acyclic molecules, can be sufficiently robust under acidic conditions to be fashioned into orally bioavailable drugs, and these structural elements are embedded in many effective therapeutic agents. The chemical stability of molecules incorporating geminal diheteroatomic motifs can be modulated by physicochemical design principles that include the judicious deployment of proximal electron-withdrawing substituents and conformational restriction. In this Perspective, we exemplify geminal diheteroatomic motifs that have been utilized in the discovery of orally bioavailable drugs or drug candidates against the backdrop of understanding their potential for chemical lability.

Recent pharmacological advances in the repurposing of artemisinin drugs

Artemisinins are a family of sesquiterpene lactones originally derived from the sweet wormwood (Artemisia annua). Beyond their well-characterized role as frontline antimalarial drugs, artemisinins have also received increased attention for other potential pharmaceutical effects, which include antiviral, antiparsitic, antifungal, anti-inflammatory, and anticancer activities. With concerted efforts in further preclinical and clinical studies, artemisinin-based drugs have the potential to be viable treatments for a great variety of human diseases. Here, we provide a comprehensive update on recent reports of pharmacological actions and applications of artemisinins outside of their better-known antimalarial role and highlight their potential therapeutic viability for various diseases.

Recent Advances in Nanoscale Metal-Organic Frameworks Towards Cancer Cell Cytotoxicity: An Overview

Abstract

The fight against cancer has always been a prevalent research topic. Nanomaterials have the ability to directly penetrate cancer cells and potentially achieve minimally invasive, precise and efficient tumor annihilation. As such, nanoscale metal organic frameworks (nMOFs) are becoming increasingly attractive as potential therapeutic agents in the medical field due to their high structural variability, good biocompatibility, ease of surface functionalization as well as their porous morphologies with tunable cavity sizes. This overview addresses five different common strategies used to find cancer therapies, while summarizing the recent progress in using nMOFs as cytotoxic cancer cell agents largely through in vitro studies, although some in vivo investigations have also been reported. Chemo and targeted therapies rely on drug encapsulation and delivery inside the cell, whereas photothermal and photodynamic therapies depend on photosensitizers. Concurrently, immunotherapy actively induces the body to destroy the tumor by activating an immune response. By choosing the appropriate metal center, ligands and surface functionalization, nMOFs can be utilized in all five types of therapies. In the last section, the future prospects and challenges of nMOFs with respect to the various therapies will be presented and discussed.

Graphic Abstract

Dihydroartemisinin ameliorates balloon injury-induced neointimal formation through suppressing autophagy in vascular smooth muscle cells

The present study was designed to investigate the therapeutic effects of injection of dihydroartemisinin (DHA) into the balloon-injured carotid arteries on balloon injury-induced neointimal formation and to explore whether autophagy is involved in the action of DHA. Percutaneous transluminal balloon angioplasty was performed in Sprague-Dawley rats to induce neointimal formation, immediately after which DHA (100 μmol/l × 1 ml) and/or Rapamycin (1 mg/100 μl), were injected into the balloon-injured carotid arteries. After 14 days, the serum samples and carotid artery tissues were harvested for analysis. Rat aortic vascular smooth muscle cells (VSMCs) were pretreated with DMSO (vehicle), DHA (1, 10, and 100 μmol/l), or 3-methyladenine (3-MA; 10 mM) for 1 h and then stimulated with platelet-derived growth factor-BB (PDGF-BB; 10 ng/ml) for another 24 h. Animal experiments showed that DHA attenuated the balloon injury-induced neointimal formation, inflammation and VSMC phenotypic transition by inhibiting the balloon injury-induced autophagy activation. In vitro results showed that DHA attenuated the PDGF-BB-induced VSMC phenotypic transition, proliferation, and migration by inhibiting the PDGF-BB-induced autophagy activation. Taken together, DHA ameliorates balloon injury-induced neointimal formation through suppressing autophagy. This study provides insights into the development of a drug-eluting stent using DHA.

N-alkyl triphenylvinylpyridinium conjugated dihydroartemisinin perturbs mitochondrial functions resulting in enhanced cancer versus normal cell toxicity

Dihydroartemisinin (DHA) is an FDA-approved antimalarial drug that has been repurposed for cancer therapy because of its preferential antiproliferative effects on cancer versus normal cells. Mitochondria represent an attractive target for cancer therapy based on their regulatory role in proliferation and cell death. This study investigates whether DHA conjugated to innately fluorescent N-alkyl triphenylvinylpyridinium (TPVP) perturbs mitochondrial functions resulting in a differential toxicity of cancer versus normal cells. TPVP-DHA treatments resulted in a dose-dependent toxicity of human melanoma and pancreatic cancer cells, whereas normal human fibroblasts were resistant to this treatment. TPVP-DHA treatments resulted in a G₁-delay of the cancer cell cycle, which was also associated with a significant inhibition of the mTOR-metabolic and ERK1/2-proliferative signaling pathways. TPVP-DHA treatments perturbed mitochondrial functions, which correlated with increases in mitochondrial fission. In summary, TPVP mediated mitochondrial targeting of DHA enhanced cancer cell toxicity by perturbing mitochondrial functions and morphology.

Ferroptosis: A Novel Mechanism of Artemisinin and its Derivatives in Cancer Therapy

BACKGROUND

Artemisinin is a sesquiterpene lactone compound with a special peroxide bridge that is tightly linked to the cytotoxicity involved in fighting malaria and cancer. Artemisinin and its derivatives (ARTs) are considered to be potential anticancer drugs that promote cancer cell apoptosis, induce cell cycle arrest and autophagy, inhibit cancer cell invasion and migration. Additionally, ARTs significantly increase intracellular Reactive Oxygen Species (ROS) in cancer cells, which result in ferroptosis, a new form of cell death, depending on the ferritin concentration. Ferroptosis is regarded as a cancer suppressor and as well as considered a new mechanism for cancer therapy.

METHODS

The anticancer activities of ARTs and reference molecules were compared by literature search and analysis. The latest research progress on ferroptosis was described, with a special focus on the molecular mechanism of artemisinin-induced ferroptosis.

RESULTS

Artemisinin derivatives, artemisinin-derived dimers, hybrids and artemisinin-transferrin conjugates, could significantly improve anticancer activity, and their IC50 values are lower than those of reference molecules such as doxorubicin and paclitaxel. The biological activities of linkers in dimers and hybrids are important in the drug design processes. ARTs induce ferroptosis mainly by triggering intracellular ROS production, promoting the lysosomal degradation of ferritin and regulating the System Xc-/Gpx4 axis. Interestingly, ARTs also stimulate the feedback inhibition pathway.

CONCLUSION

Artemisinin and its derivatives could be used in the future as cancer therapies with broader applications due to their induction of ferroptosis. Meanwhile, more attention should be paid to the development of novel artemisinin-related drugs based on the mechanism of artemisinininduced ferroptosis.

Sesquiterpene Polygodial from Drimys brasiliensis (Winteraceae) Down-Regulates Implant-Induced Inflammation and Fibrogenesis in Mice

Drimys brasiliensis (Winteraceae) has been investigated in traditional medicine for its anti-inflammatory properties to treat gastric ulcers and allergic and respiratory system diseases as well as for cancer treatment. In this work, we investigate the ability of the sesquiterpene polygodial, isolated from D. brasiliensis stem barks, to modulate the chronic inflammatory response induced by polyester-polyurethane sponge implants in C57BL/6J mice. Daily treatment with polygodial inhibited the macrophage content in the implants as determined by the activity of the N-acetyl-β-d-glucosaminidase enzyme as well as decreased the levels of CXCL1/KC and CCL2/JE/MCP-1 pro-inflammatory chemokines and the presence of mast cells along the formed fibrovascular tissue. Similarly, the deposition of a new extracellular matrix (total collagen and type I and III collagen fibers) as well as the production of the TGF-β1 cytokine were attenuated in implants treated with polygodial, showing for the first time its antifibrogenic capacity. The hemoglobin content, the number of newly formed vessels, and the levels of VEGF cytokine, which were used as parameters for the assessment of the neovascularization of the implants, did not change after treatment with polygodial. The anti-inflammatory and antifibrogenic effects of polygodial over the components of the granulation tissue induced by the sponge implant indicate a therapeutic potential for the treatment of inflammatory diseases associated with the development of fibrovascular tissue.

Supramolecular hybrids of carbon dots and dihydroartemisinin for enhanced anticancer activity and mechanism analysis

Dihydroartemisinin (DHA) has been regarded as a potential anticancer agent in recent years. Nevertheless, the clinical applications of DHA are seriously restricted as a result of its intrinsic characteristics, such as poor water solubility, instability, and fast clearance. Herein, a type of fluorescent nanoparticles was successfully fabricated via supramolecular assembling of carbon dots (CDs) and DHA. The formulated CDs-DHA fluorescent nanoparticles not only significantly improve the solubility and stability of DHA, but also possess favorable biocompatibility and pH-dependent drug release behavior. In particular, the hybrids of CDs and DHA as nanocarriers can effectively promote the endocytosis of DHA and exhibit enhanced antitumor effects compared with free DHA in vitro and in vivo. In addition, we also explore the possible action mechanism of CDs-DHA through flow cytometric assay, transfection and western blot analysis. The results indicate that CDs-DHA nanoparticles suppress the progression of hepatic carcinoma through inducing apoptosis and inhibiting glucose metabolism, and the mechanism is related to the downregulation of PKM2 expression and the suppression of the Akt/mTOR signaling pathway, which may provide a potential therapeutic target for hepatic carcinoma treatment. This work emphasizes the great potential of utilizing CDs as a safe and convenient platform to deliver DHA for efficient cancer therapy, and the study on the anticancer mechanism can also offer theoretical support for the clinical application of DHA.

Intrinsic Defects in Polymeric Carbon Nitride for Photocatalysis Applications

Introducing intrinsic defects in polymeric carbon nitride (PCN) without the addition of exotic atoms have been verified as an available strategy to boost the photocatalytic performance. This minireview focuses on the fundamental classifications and positive roles of intrinsic defects in PCN for photocatalysis applications. The intrinsic defects in PCN are classified into several types, such as nitrogen vacancy, carbon vacancy and derivative functional groups such as cyano, amino and cyanamide groups. The critical roles of these defects on the electronic configuration, charge transfer and surface properties of PCN are also carefully classified and elaborated. Furthermore, the photocatalysis applications of the defective PCN including photocatalytic water splitting, N₂ fixation, H₂ O₂ production, CO₂ reduction and NO removal are summarized. In the end, the challenges and opportunities of defect chemistry in PCN for photocatalysis field are presented.

Pyrimethamine exerts significant antitumor effects on human ovarian cancer cells both in vitro and in vivo

Pyrimethamine has been used principally to treat infections from protozoan parasites. Although previous studies have shown that pyrimethamine exhibited anticancer activity by inducing cellular apoptosis, there are none that show that pyrimethamine possesses anticancer activity with respect to ovarian cancer. We examined the roles of pyrimethamine on apoptosis and proliferation, DNA damage, and cell cycle distribution of human ovarian cancer cell lines in vitro. To investigate the antitumor efficacy of pyrimethamine in vivo, we established two intraperitoneal ovarian carcinoma models in nude mice. Pyrimethamine significantly induced apoptosis of ovarian cancer cells via growth inhibition, cell cycle arrest, and nuclear DNA damage in vitro and manifested antitumor activity by inhibiting tumor growth, thereby prolonging the survival time of tumor-bearing mice. We also demonstrated that pyrimethamine increased the expression of caspase-9 and decreased the expression of X-linked inhibitor of apoptosis protein. In conclusion, the antitumor effects of pyrimethamine were associated with enhanced apoptosis of tumor cells and inhibition of the growth of intratumoral microvessels. Our results indicate that pyrimethamine may provide an effective approach toward inhibiting the growth of ovarian cancer with minimal adverse effects.

Natural Sesquiterpene Lactones in the Prevention and Treatment of Inflammatory Disorders and cancer: A Systematic Study of this Emerging Therapeutic Approach based on Chemical and Pharmacological Aspect

Background and Introduction:

Sesquiterpene lactones are a class of secondary metabolite that contains sesquiterpenoids and lactone ring as pharmacophore moiety. A large group of bioactive secondary metabolites such as phytopharmaceuticals belong to this category. From the Asteraceae family-based medicinal plants, more than 5,000 sesquiterpene lactones have been reported so far. Sesquiterpene lactone-based pharmacophore moieties hold promise for broad-spectrum biological activities against cancer, inflammation, parasitic, bacterial, fungal, viral infection and other functional disorders. Moreover, these moiety based phytocompounds have been highlighted with a new dimension in the natural drug discovery program worldwide after the 2015 Medicine Nobel Prize achieved by the Artemisinin researchers.

Objective:

These bitter substances often contain an α, β-unsaturated-γ-lactone as a major structural backbone, which in recent studies has been explored to be associated with anti-tumor, cytotoxic, and anti-inflammatory action. Recently, the use of sesquiterpene lactones as phytomedicine has been increased. This study will review the prospect of sesquiterpene lactones against inflammation and cancer.

Methods:

Hence, we emphasized on the different features of this moiety by incorporating its structural diversity on biological activities to explore structure-activity relationships (SAR) against inflammation and cancer.

Results:

How the dual mode of action such as anti-inflammatory and anti-cancer has been exhibitedby these phytopharmaceuticals will be forecasted in this study. Furthermore, the correlation of anti-inflammatory and anti-cancer activity executed by the sesquiterpene lactones for fruitful phytotherapy will also be revealed in the present review in the milieu of pharmacophore activity relation and pharmacodynamics study as well.

Conclusion:

So, these metabolites are paramount in phytopharmacological aspects. The present discussion on the future prospect of this moiety based on the reported literature could be a guide for anti-inflammatory and anti-cancer drug discovery programs for the upcoming researchers.

Artemisinin Derivatives Stimulate DR5-Specific TRAIL-Induced Apoptosis by Regulating Wildtype P53

Artemisinin derivatives, widely known as commercial anti-malaria drugs, may also have huge potential in treating cancer cells. It has been reported that artemisinin derivatives can overcome resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in liver and cervical cancer cells. In our study, we demonstrated that artesunate (ATS) and dihydroartemisinin (DHA) are more efficient in killing colon cancer cells compared to artemisinin (ART). ATS/DHA induces the expression of DR5 in a P53 dependent manner in HCT116 and DLD-1 cells. Both ATS and DHA overcome the resistance to DHER-induced apoptosis in HCT116, mainly through upregulating death receptor 5 (DR5). We also demonstrate that DHA sensitizes HCT116 cells to DHER-induced apoptosis via P53 regulated DR5 expression in P53 knockdown assays. Nevertheless, a lower effect was observed in DLD-1 cells, which has a single Ser241Phe mutation in the P53 DNA binding domain. Thus, the status of P53 could be one of the determinants of TRAIL resistance in some cancer cells. Finally, the combination treatment of DHA and the TRAIL variant DHER increases cell death in 3D colon cancer spheroid models, which shows its potential as a novel therapy.

Synthesis of Tamoxifen-Artemisinin and Estrogen-Artemisinin Hybrids Highly Potent Against Breast and Prostate Cancer

In the search for new and effective treatments of breast and prostate cancer, a series of hybrid compounds based on tamoxifen, estrogens, and artemisinin were successfully synthesized and analyzed for their in vitro activities against human prostate (PC-3) and breast cancer (MCF-7) cell lines. Most of the hybrid compounds exhibit a strong anticancer activity against both cancer cell lines - for example, EC50 (PC-3) down to 1.07 μM, and EC50 (MCF-7) down to 2.08 μM - thus showing higher activities than their parent compounds 4-hydroxytamoxifen (afimoxifene, 7; EC50 =75.1 (PC-3) and 19.3 μM (MCF-7)), dihydroartemisinin (2; EC50 =263.6 (PC-3) and 49.3 μM (MCF-7)), and artesunic acid (3; EC50 =195.1 (PC-3) and 32.0 μM (MCF-7)). The most potent compounds were the estrogen-artemisinin hybrids 27 and 28 (EC50 =1.18 and 1.07 μM, respectively) against prostate cancer, and hybrid 23 (EC50 =2.08 μM) against breast cancer. These findings demonstrate the high potential of hybridization of artemisinin and estrogens to further improve their anticancer activities and to produce synergistic effects between linked pharmacophores.

Artemisinin and its derivatives: a promising cancer therapy

The world is experiencing a cancer epidemic and an increase in the prevalence of the disease. Cancer remains a major killer, accounting for more than half a million deaths annually. There is a wide range of natural products that have the potential to treat this disease. One of these products is artemisinin; a natural product from Artemisia plant. The Nobel Prize for Medicine was awarded in 2015 for the discovery of artemisinin in recognition of the drug's efficacy. Artemisinin produces highly reactive free radicals by the breakdown of two oxygen atoms that kill cancerous cells. These cells sequester iron and accumulate as much as 1000 times in comparison with normal cells. Generally, chemotherapy is toxic to both cancerous cells and normal cells, while no significant cytotoxicity from artemisinin to normal cells has been found in more than 4000 case studies, which makes it far different than conventional chemotherapy. The pleiotropic response of artemisinin in cancer cells is responsible for growth inhibition by multiple ways including inhibition of angiogenesis, apoptosis, cell cycle arrest, disruption of cell migration, and modulation of nuclear receptor responsiveness. It is very encouraging that artemisinin and its derivatives are anticipated to be a novel class of broad-spectrum antitumor agents based on efficacy and safety. This review aims to highlight these achievements and propose potential strategies to develop artemisinin and its derivatives as a new class of cancer therapeutic agents.

Antimalarial agent artesunate induces G0/G1 cell cycle arrest and apoptosis via increasing intracellular ROS levels in normal liver cells

Artesunate (ARS) has been shown to be highly effective against chloroquine-resistant malaria. In vitro studies reported that ARS has anticancer effects; however, its detrimental action on cancer cells may also play a role in its toxicity toward normal cells and its potential toxicity has not been sufficiently researched. In this study, we investigated the possible cytotoxic effects using normal BRL-3A and AML12 liver cells. The results showed that ARS dose-dependently inhibited cell proliferation and arrested the G0/G1 phase cell cycle in both BRL-3A and AML12 liver cells. Western blotting demonstrated that ARS induced a significant downregulation of cyclin-dependent kinase-2 (CDK2), CDK4, cyclin D1, and cyclin E1 in various levels and then caused apoptosis when the Bcl-2/Bax ratio decreased. Conversely, the levels of intracellular reactive oxygen species (ROS) were increased. The ROS scavenger N-acetylcysteine can significantly inhibit cell cycle arrest and apoptosis induced by ARS. Thus, the data confirmed that ARS exposure impairs normal liver cell proliferation by inducing G0/G1 cell cycle arrest and apoptosis, and this detrimental action may be associated with intracellular ROS accumulation. Collectively, the possible side effects of ARS on healthy normal cells cannot be neglected when developing therapies.

Oxidation of Erythrocytes Enhance the Production of Reactive Species in the Presence of Artemisinins

In red blood cells, hemoglobin iron represents the most plausible candidate to catalyze artemisinin activation but the limited reactivity of iron bound to hemoglobin does not play in favor for its direct involvement. Denatured hemoglobin appears a more likely candidate for artemisinin redox activation because it is expected to contain reactive iron and it has been described to release free heme and/or iron in erythrocyte. The aim of our study is to investigate, using three different methods: fluorescence, electron paramagnetic resonance and liquid chromatography coupled to mass spectrometry, how increasing the level of accessible iron into the red blood cells can enhance the reactive oxygen species (ROS) production derived from artemisinin. The over-increase of iron was achieved using phenylhydrazine, a strong oxidant that causes oxidative stress within erythrocytes, resulting in oxidation of oxyhemoglobin and leading to the formation of methemoglobin, which is subsequently converted into irreversible hemichromes (iron (III) compounds). Our findings confirmed, using the iron III chelator, desferrioxamine, the indirect participation of iron (III) compounds in the activation process of artemisinins. Furthermore, in strong reducing conditions, the activation of artemisinin and the consequent production of ROS was enhanced. In conclusion, we demonstrate, through the measurement of intra-erythrocytic superoxide and hydrogen peroxide production using various methods, that artemisinin activation can be drastically enhanced by pre-oxidation of erythrocytes.

Combination Therapies of Artemisinin and its Derivatives as a Viable Approach for Future Cancer Treatment

BACKGROUND

Many anticancer drugs have been developed for clinical usage till now, but the major problem is the development of drug-resistance over a period of time in the treatment of cancer. Anticancer drugs produce huge adverse effects, ultimately leading to death of the patient. Researchers have been focusing on the development of novel molecules with higher efficacy and lower toxicity; the anti-malarial drug artemisinin and its derivatives have exhibited cytotoxic effects.

METHODS

We have done extensive literature search for artemisinin for its new role as anti-cancer agent for future treatment. Last two decades papers were referred for deep understanding to strengthen its role.

RESULT

Literature shows changes at 9, 10 position in the artemisinin structure produces anticancer activity. Artemisinin shows anticancer activity in leukemia, hepatocellular carcinoma, colorectal and breast cancer cell lines. Artemisinin and its derivatives have been studied as combination therapy with several synthetic compounds, RNA interfaces, recombinant proteins and antibodies etc., for synergizing the effect of these drugs. They produce an anticancer effect by causing cell cycle arrest, regulating signaling in apoptosis, angiogenesis and cytotoxicity activity on the steroid receptors. Many novel formulations of artemisinin are being developed in the form of carbon nanotubes, polymer-coated drug particles, etc., for delivering artemisinin, since it has poor water/ oil solubility and is chemically unstable.

CONCLUSION

We have summarize the combination therapies of artemisinin and its derivatives with other anticancer drugs and also focussed on recent developments of different drug delivery systems in the last 10 years. Various reports and clinical trials of artemisinin type drugs indicated selective cytotoxicity along with minimal toxicity thus projecting them as promising anti-cancer agents in future cancer therapies.

Activation of artemisinin and heme degradation in Leishmania tarentolae promastigotes: A possible link

Endoperoxides (EPs) appear to be promising drug candidates against protozoal diseases, including malaria and leishmaniasis. Previous studies have shown that these drugs need an intracellular activation to exert their pharmacological potential. The efficiency of these drugs is linked to the extensive iron demand of these intracellular protozoal parasites. An essential step of the activation mechanism of these drugs is the formation of radicals in Leishmania. Iron is a known trigger for intracellular radical formation. However, the activation of EPs by low molecular iron or by heme iron may strongly depend on the structure of the EPs themselves. In this study, we focused on the activation of artemisinin (Art) in Leishmania tarentolae promastigotes (LtP) in comparison to reference compounds. Viability assays in different media in the presence of different iron sources (hemin/fetal calf serum) showed that IC50 values of Art in LtP were modulated by assay conditions, but overall were within the low micromolar range. Low temperature electron paramagnetic resonance (EPR) spectroscopy of LtP showed that Art shifted the redox state of the labile iron pool less than the EP ascaridole questioning its role as a major activator of Art in LtP. Based on the high reactivity of Art with hemin in previous biomimetic experiments, we focused on putative heme-metabolizing enzymes in Leishmania, which were so far not well described. Inhibitors of mammalian heme oxygenase (HO; tin and chromium mesoporphyrin) acted antagonistically to Art in LtP and boosted its IC50 value for several magnitudes. By inductively coupled plasma methods (ICP-OES, ICP-MS) we showed that these inhibitors do not block iron (heme) accumulation, but are taken up and act within LtP. These inhibitors blocked the conversion of hemin to bilirubin in LtP homogenates, suggesting that an HO-like enzyme activity in LtP exists. NADPH-dependent degradation of Art and hemin was highest in the small granule and microsomal fractions of LtP. Photometric measurements in the model Art/hemin demonstrated that hemin requires reduction to heme and that subsequently an Art/heme complex (λmax 474 nm) is formed. EPR spin-trapping in the system Art/hemin revealed that NADPH, ascorbate and cysteine are suitable reductants and finally activate Art to acyl-carbon centered radicals. These findings suggest that heme is a major activator of Art in LtP either via HO-like enzyme activities and/or chemical interaction of heme with Art.

Dihydroartemisinin-Bile Acid Hybridization as an Effective Approach to Enhance Dihydroartemisinin Anticancer Activity

A series of hybrid compounds based on natural products-bile acids and dihydroartemisinin-were prepared by different synthetic methodologies and investigated for their in vitro biological activity against HL-60 leukemia and HepG2 hepatocellular carcinoma cell lines. Most of these hybrids presented significantly improved antiproliferative activities with respect to dihydroartemisinin and the parent bile acid. The two most potent hybrids of the series exhibited a 10.5- and 15.4-fold increase in cytotoxic activity respect to dihydroartemisinin alone in HL-60 and HepG2 cells, respectively. Strong evidence that an ursodeoxycholic acid hybrid induced apoptosis was obtained by flow cytometric analysis and western blot analysis.

MOF nanoparticles with encapsulated dihydroartemisinin as a controlled drug delivery system for enhanced cancer therapy and mechanism analysis

Schematic illustration of (a) the preparation of DHA@ZIF-8 NPs and (b) their application for cancer therapy.

Recent Progress in Ferroptosis Inducers for Cancer Therapy

Ferroptosis is a newly discovered form of regulated cell death that is the nexus between metabolism, redox biology, and human health. Emerging evidence shows the potential of triggering ferroptosis for cancer therapy, particularly for eradicating aggressive malignancies that are resistant to traditional therapies. Recently, there has been a great deal of effort to design and develop anticancer drugs based on ferroptosis induction. Recent advances of ferroptosis-inducing agents at the intersection of chemistry, materials science, and cancer biology are presented. The basis of ferroptosis is summarized first to highlight the feasibility and characteristics of triggering ferroptosis for cancer therapy. A literature review of ferroptosis inducers (including small molecules and nanomaterials) is then presented to delineate their design, action mechanisms, and anticancer applications. Finally, some considerations for research on ferroptosis inducers are spotlighted, followed by a discussion on the challenges and future development directions of this burgeoning field.

Antimalarial Drugs Enhance the Cytotoxicity of 5-Aminolevulinic Acid-Based Photodynamic Therapy against the Mammary Tumor Cells of Mice In Vitro

Artemisinin and its derivatives, including artesunate (ART) and artemether (ARM), exert anticancer effects in the micromolar range in drug and radiation-resistant cell lines. Artemisinin has been reported to sensitize cervical cancer cells to radiotherapy. In the present study, we determined whether ART and ARM could enhance the cytotoxicity of 5-aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT) against the mammary tumor cells of mice. The corrected PpIX fluorescence intensities in the control, 5-ALA, 5-ALA + ART, and 5-ALA + ARM groups were 3.385 ± 3.730, 165.7 ± 33.45, 139.0 ± 52.77, and 165.4 ± 51.10 a.u., respectively. At light doses of 3 and 5 J/cm², the viability of 5-ALA-PDT-treated cells significantly decreased with ART (p < 0.01 and p < 0.01) and ARM treatment (p < 0.01 and p < 0.01). Besides, the number of annexin V-FITC and ethidium homodimer III-positive cells was greater in the 5-ALA-PDT with ARM group than that in the other groups. N-acetylcysteine could not significantly inhibit the percentages of apoptotic cells or inviable cells induced by 5-ALA-PDT with ARM. These reactive oxygen species-independent mechanisms might enhance cytotoxicity in 5-ALA-PDT with ARM-treated tumor cells, suggesting that the use of 5-ALA-PDT with ARM could be a new strategy to enhance PDT cytotoxicity against tumor cells. However, as these results are only based on in vitro studies, further in vivo investigations are required.

Artemisinin inhibits breast cancer-induced osteolysis by inhibiting osteoclast formation and breast cancer cell proliferation

In addition to being used to treat malaria, artemisinin (Art) can be used as an anti-inflammatory and antitumor agent. In this study, we evaluated the effects of Art on osteoclast formation and activation and on the development of breast cancer cells in bone. To evaluate the effect of Art on osteoclast differentiation in vitro, we treated bone marrow-derived macrophages (BMMs) with various concentrations of Art and evaluated the expression of genes and proteins involved in osteoclast formation. We also performed cell counting kit-8 assays to evaluate the toxicity of Art in BMMs and MDA-MB-231 cells. We also performed Transwell assays, wound-healing assays, colony formation assays, and cell apoptosis assays to evaluate the effect of Art in MDA-MB-231 cells. We also evaluated the effect of Art in an in vivo osteoclast bone resorption assay using a nude mouse model. We demonstrated that Art inhibits the differentiation and establishment of osteoclasts even though Art is not toxic to osteoclasts. In addition, Art reduced expression of genes involved in osteoclast formation and inhibited osteoclast bone resorption in a concentration-dependent manner. Based on our data, we believe that Art can inhibit proliferation of breast cancer cells by activating apoptosis pathways, and inhibit osteoclast formation and differentiation by inhibiting activation of cathepsin K, ATPase H+ transporting V0 subunit D2, nuclear factor of activated T cells 1, calcitonin receptor, and tartrate-resistant acid phosphatase and by inhibiting nuclear factor-κB activation.

Simultaneous Quantification of Five Sesquiterpene Components after Ultrasound Extraction in Artemisia annua L. by an Accurate and Rapid UPLC⁻PDA Assay

Objective: To develop an accurate and rapid ultra-performance liquid chromatography (UPLC) coupled with a photodiode array (PDA) method for the simultaneous determination of artemisinin (Art), arteannuin B (Art B), arteannuin C (Art C), dihydroartemisinic acid (DHAA) and artemisinic acid (AA) in Artemisia annua L. Methodology: Chromatography separation was performed on an ACQUITY UPLC BEH C18 Column with isocratic elution; the mobile phase was 0.1% formic acid aqueous solution (A) and acetonitrile (B) (A:B = 40:60, v/v). Data were recorded at an ultraviolet (UV) wavelength of 191 nm for Art, Art C, DHAA and AA, and 206 nm for Art B. Results: The calibration curves of the five sesquiterpene components were all linear with correlation coefficients more than 0.9990. The linear ranges were 31.44–1572 μg/mL, 25.48–1274 μg/mL, 40.56–2028 μg/mL, 31.44–1572 μg/mL and 26.88–1396 μg/mL for Art, Art B, Art C, DHAA and AA, respectively. The precision ranged from 0.08% to 2.88%, the stability was from 0.96% to 1.66%, and the repeatability was all within 2.42% and had a mean extraction recovery of 96.5% to 100.6%. Conclusion: The established UPLC–PDA method would be valuable for improving the quantitative analysis of sesquiterpene components in Artemisia annua L.

Cyclodextrin-based delivery systems for cancer treatment

Cyclodextrins, one of safe excipients, are able to form host-guest complexes with fitted molecules given the unique nature imparted by their structure in result of a number of pharmaceutical applications. On the other hand, targeted or responsive materials are appealing therapeutic platforms for the development of next-generation precision medications. Meanwhile, cyclodextrin-based polymers or assemblies can condense DNA and RNA in result to be used as genetic therapeutic agents. Armed with a better understanding of various pharmaceutical mechanisms, especially for cancer treatment, researchers have made lots of works about cyclodextrin-based drug delivery systems in materials chemistry and pharmaceutical science. This Review highlights recent advances in cyclodextrin-based delivery systems for cancer treatment capable of targeting or responding to the physiological environment. Key design principles, challenges and future directions, including clinical translation, of cyclodextrin-based delivery systems are also discussed.

Synthesis of Artemisinin-Estrogen Hybrids Highly Active against HCMV, P. falciparum, and Cervical and Breast Cancer

Artemisinin-estrogen hybrids were for the first time both synthesized and investigated for their in vitro biological activity against malaria parasites (Plasmodium falciparum 3D7), human cytomegalovirus (HCMV), and a panel of human malignant cells of gynecological origin containing breast (MCF7, MDA-MB-231, MDA-MB-361, T47D) and cervical tumor cell lines (HeLa, SiHa, C33A). In terms of antimalarial efficacy, hybrid 8 (EC50 = 3.8 nM) was about two times more active than its parent compound artesunic acid (7) (EC50 = 8.9 nM) as well as the standard drug chloroquine (EC50 = 9.8 nM) and was, therefore, comparable to the clinically used dihydroartemisinin (6) (EC50 = 2.4 nM). Furthermore, hybrids 9-12 showed a strong antiviral effect with EC50 values in the submicromolar range (0.22-0.38 μM) and thus possess profoundly stronger anti-HCMV activity (approximately factor 25) than the parent compound artesunic acid (7) (EC50 = 5.41 μM). These compounds also exerted a higher in vitro anti-HCMV efficacy than ganciclovir used as the standard of current antiviral treatment. In addition, hybrids 8-12 elicited substantially more pronounced growth inhibiting action on all cancer cell lines than their parent compounds and the reference drug cisplatin. The most potent agent, hybrid 12, exhibited submicromolar EC50 values (0.15-0.93 μM) against breast cancer and C33A cell lines.