A novel monocarbonyl analogue of curcumin, (1E,4E)-1,5-bis(2,3-dimethoxyphenyl)penta-1,4-dien-3-one, induced cancer cell H460 apoptosis via activation of endoplasmic reticulum stress signaling pathway

Discovery of cinnamylaldehyde-derived mono-carbonyl curcumin analogs as anti-gastric cancer agents via suppression of STAT3 and AKT pathway

The structural modification of curcumin has always been a hotspot in drug development. In this paper, a class of cinnamylaldehyde-derived mono-carbonyl curcumin analogs (MCAs) with 7-carbon-links were designed and synthesized and their anticancer properties were evaluated. Through screening anti-gastric cancer activity of these compounds, H1 exhibited the strongest cytotoxic activity by inhibiting cell viability and colony formation, inducing cell cycle G2/M phase arrest in vitro (SGC-7901 and AGS gastric cancer cells). Moreover, the SGC-7901 subcutaneous tumor-bearing mice studies revealed that H1 significantly inhibited the tumor growth of gastric cancer. We explored the possible potential targets of H1 through network pharmacology. Mechanistically, our results demonstrated that H1 showed potential anti-gastric cancer activity through suppression of the STAT3 and AKT signaling pathway in vitro and in vivo, which was validated by molecular docking. Overall, our results indicate the potential of H1 as a potent chemotherapeutic drug against gastric cancer.

Curcumin and its Derivatives Targeting Multiple Signaling Pathways to Elicit Anticancer Activity: A Comprehensive Perspective

The uncontrolled growth and spread of aberrant cells characterize the group of disorders known as cancer. According to GLOBOCAN 2022 analysis of cancer patients in either developed countries or developing countries the main concern cancers are breast cancer, lung cancer, and liver cancer which may rise eventually. Natural substances with dietary origins have gained interest for their low toxicity, anti-inflammatory, and antioxidant effects. The evaluation of dietary natural products as chemopreventive and therapeutic agents, the identification, characterization, and synthesis of their active components, as well as the enhancement of their delivery and bioavailability, have all received significant attention. Thus, the treatment strategy for concerning cancers must be significantly evaluated and may include the use of phytochemicals in daily lifestyle. In the present perspective, we discussed one of the potent phytochemicals, that has been used over the past few decades known as curcumin as a panacea drug of the "Cure-all" therapy concept. In our review firstly we included exhausted data from in vivo and in vitro studies on breast cancer, lung cancer, and liver cancer which act through various cancer-targeting pathways at the molecular level. Now, the second is the active constituent of turmeric known as curcumin and its derivatives are enlisted with their targeted protein in the molecular docking studies, which help the researchers design and synthesize new curcumin derivatives with respective implicated molecular and cellular activity. However, curcumin and its substituted derivatives still need to be investigated with unknown targeting mechanism studies in depth.

Curcuminoids as Anticancer Drugs: Pleiotropic Effects, Potential for Metabolic Reprogramming and Prospects for the Future

The number of published studies on curcuminoids in cancer research, including its lead molecule curcumin and synthetic analogs, has been increasing substantially during the past two decades. Insights on the diversity of inhibitory effects they have produced on a multitude of pathways involved in carcinogenesis and tumor progression have been provided. As this wealth of data was obtained in settings of various experimental and clinical data, this review first aimed at presenting a chronology of discoveries and an update on their complex in vivo effects. Secondly, there are many interesting questions linked to their pleiotropic effects. One of them, a growing research topic, relates to their ability to modulate metabolic reprogramming. This review will also cover the use of curcuminoids as chemosensitizing molecules that can be combined with several anticancer drugs to reverse the phenomenon of multidrug resistance. Finally, current investigations in these three complementary research fields raise several important questions that will be put among the prospects for the future research related to the importance of these molecules in cancer research.

Design, synthesis and evaluation of monoketene compounds as novel potential Parkinson's disease agents by suppressing ER stress via AKT

Curcumin is identified that it has the potential to treat Parkinson's disease (PD), but its instability limits its further application in clinic. The mono-carbonyl analogs of curcumin (MACs) with diketene structure can effectively improve its stability, but it is highly toxic. In the present study, a less cytotoxic and more stable monoketene MACs skeleton S2 was obtained, and a series of monoketene MACs were synthesized by combining 4-hydroxy-3‑methoxy groups of curcumin. In the 6-OHDA-induced PD's model in-vitro, some compounds exhibited significant neurotherapeutic effect. The quantitative structure-activity relationship (QSAR) model established by the random forest algorithm (RF) for the cell viability rate of above compounds showed that the statistical results are good (R² = 0.883507), with strong reliability. Among all compounds, the most active compound A4 played an important role in neuroprotection in the PD models both in vitro and in vivo by activating AKT pathway, and then inhibiting the apoptosis of cells caused by endoplasmic reticulum (ER) stress. In the PD model in-vivo, compound A4 significantly improved survival of dopaminergic neurons and the contents of neurotransmitters. It also enhanced the retention of nigrostriatal function which was better than the effect in the mice treated by Madopar, a classical clinical drug for PD. In summary, we screened out the compound A4 with high stability, less cytotoxic monoketene compounds. And these founding provide evidence that the compound A4 can protect dopaminergic neurons via activating AKT and subsequently suppressing ER stress in PD.

Corynoxine suppresses pancreatic cancer growth primarily via ROS-p38 mediated cytostatic effects

BACKGROUND

Pancreatic cancer is among the most common malignant tumours, and effective therapeutic strategies are still lacking. While Corynoxine (Cory) can induce autophagy in neuronal cells, it remains unclear whether Cory has anti-tumour activities against pancreatic cancer.

METHODS

Two pancreatic cancer cell lines, Patu-8988 and Panc-1, were used. Effects of Cory were evaluated by cell viability analysis, EdU staining, TUNEL assay, colony formation assay, and flow cytometry. Quantitative PCR and Western blot were performed to analyse mRNA and protein levels, respectively. In vivo anti-tumour efficacy of Cory was determined by a xenograft model.

RESULTS

Cory treatment inhibited cell proliferation, induced endoplasmic reticulum (ER) stress, and triggered apoptosis in the pancreatic cancer cell lines. CHOP knockdown-mediated inhibition of ER stress alleviated the Cory-induced apoptosis but showed a limited effect on cell viability. Cory induced cell death partially via promoting reactive oxygen species (ROS) production and activating p38 signalling. Pretreatment with ROS scavenger N-acetylcysteine and p38 inhibitor SB203580 relieved the Cory-induced inhibition on cell growth. Cory remarkably blocked pancreatic tumour growth in vivo.

CONCLUSIONS

Cory exerts an anti-tumour effect on pancreatic cancer primarily via ROS-p38-mediated cytostatic effects. Cory may serve as a promising therapeutic agent for pancreatic cancer.

Rational design, synthesis, and pharmacological characterisation of dicarbonyl curcuminoid analogues with improved stability against lung cancer via ROS and ER stress mediated cell apoptosis and pyroptosis

Curcumin is a natural medicine with a wide range of anti-tumour activities. However, due to β-diketone moiety, curcumin exhibits poor stability and pharmacokinetics which significantly limits its clinical applications. In this article, two types of dicarbonyl curcumin analogues with improved stability were designed through the calculation of molecular stability by density functional theory. Twenty compounds were synthesised, and their anti-tumour activity was screened. A plurality of analogues had significantly stronger activity than curcumin. In particular, compound B2 ((2E,2'E)-3,3'-(1,4-phenylene)bis(1-(2-chlorophenyl)prop-2-en-1-one)) exhibited excellent anti-lung cancer activity in vivo and in vitro. In addition, B2 could upregulate the level of reactive oxygen species in lung cancer cells, which in turn activated the endoplasmic reticulum stress and led to cell apoptosis and pyroptosis. Taken together, curcumin analogue B2 is expected to be a novel candidate for lung cancer treatment with improved chemical and biological characteristics.

Perspectives for synthetic curcumins in chemoprevention and treatment of cancer: An update with promising analogues

Curcumin, a pure compound extracted from the flowering plant, turmeric (Curcuma longa. Zingiberaceae), is a common dietary ingredient found in curry powder. It has been studied extensively for its anti-inflammatory, antioxidant, antimicrobial and anti-tumour activities. Evidence is accumulating demonstrating its potential in chemoprevention and as an anti-tumour agent for the treatment of cancer. Despite demonstrated safety and tolerability, the clinical application of curcumin is frustrated by its poor solubility, metabolic instability and low oral bioavailability. Consequently researchers have tried novel techniques of formulation and delivery as well as synthesis of analogues with enhanced properties to overcome these barriers. This review presents the synthetic analogues of curcumin that have proven their anticancer potential from different studies. It also highlights studies that combined these analogues with approved chemotherapies and delivered them via novel techniques. Currently, there are no reports of clinical studies on any of the synthetic congeners of curcumin and this presents an opportunity for future research. This review presents the synthetic analogues of curcumin and makes a compelling argument for their potential application in the management of cancerous disease.

Curcumin induces apoptosis and inhibits the growth of adrenocortical carcinoma: Identification of potential candidate genes and pathways by transcriptome analysis

Adrenocortical carcinoma (ACC) is an endocrine tumour with high malignancy, high invasiveness and poor prognosis. Curcumin, a major component in turmeric, has been reported to have good efficacy and biological safety in treating cancer. However, the role and mechanism of curcumin in ACC have not yet been fully investigated and were thus the focus of this study. In vitro, ACC SW-13 and NCI-H295R cells were treated with curcumin and their viability, migration and invasion were assessed by CCK-8 and Transwell assays. Apoptosis was detected via flow cytometry and western blotting. High-throughput sequencing and comprehensive bioinformatics analyses were performed to elucidate the molecular processes underlying curcumin activity. In vivo, SW-13 cells were injected into nude mice, and the tumour volumes and weights were observed after 2 weeks of curcumin treatment. Organelle changes were observed by electron microscopy, and potential candidate genes and pathways were analysed by RT-qPCR and western blotting. The role of the CHOP target gene in curcumin-induced ACC cell apoptosis was verified via lentiviral transfection experiments. Curcumin inhibited the viability, migration and invasion, and induced the apoptosis of ACC cells. Transcriptome sequencing analysis showed that curcumin treatment markedly changed the gene expression levels. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses showed that the MAPK and endoplasmic reticulum (ER) stress pathways were the predominant pathways associated with curcumin-induced apoptosis of ACC cells. Subsequent in vivo and in vitro results demonstrated that the JNK, p38 MAPK and ER stress pathways were activated in curcumin-treated ACC cells, and that C/EBP homologous protein induction was responsible for curcumin-induced apoptosis of ACC cells. In summary, curcumin induced ACC cell apoptosis and inhibited tumour growth by activating the JNK, p38 MAPK and ER stress pathways. Thus, curcumin may be a potential therapeutic drug for ACC.

Design, synthesis, and evaluation of mono-carbonyl analogues of curcumin (MCACs) as potential antioxidants against periodontitis

BACKGROUND AND OBJECTIVE

The application of curcumin is limited by its instability. Mono-carbonyl analogues of curcumin (MCACs) are structurally stable, yet the intermediate bridging ketones in their skeletons account for increased toxicity. This study aimed to synthesize and screen MCACs that exhibit low cytotoxicity and high antioxidant ability, and the effects of MCACs on experimental periodontitis were also investigated.

MATERIALS AND METHODS

The cytotoxicity of MCACs on MC3 T3-E1 was determined by MTT assay. The antioxidant capacity was investigated by the cell viability against H₂ O₂ -induced damage and the level of reactive oxygen species (ROS) and malondialdehyde (MDA). The localization and protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was detected by immunofluorescence and western blot, respectively. In addition, MCAC was intragastrically administrated in rats with ligature-induced experimental periodontitis. The effects were assessed by bone resorption, as well as the immunohistology staining of inflammatory and oxidative stress markers.

RESULTS

MCACs with cyclopentanone and containing pyrone showed lower toxicity than natural curcumin were synthesized (1A-10A, 1H-10H), among which, 1A exhibited the most potent cytoprotective effect against H₂ O₂ -induced damage. Such effects could be explained by the reduced MDA and ROS level, possibly through the nucleus translocation of Nrf2 and the induction of HO-1. Micro-CT results further indicated that 1A significantly reduced bone loss, along with an increased level of Nrf2 and HO-1, and decreased TNF-α and IL-1β.

CONCLUSION

The present study has synthesized a novel antioxidant MCAC 1A with good biosafety and stability. MCAC 1A could serve as a host response modulator with preventive and protective effects on periodontitis.

The Thioredoxin System: A Promising Target for Cancer Drug Development

The thioredoxin system is highly conserved system found in all living cells and comprises NADPH, thioredoxin, and thioredoxin reductase. This system plays a critical role in preserving a reduced intracellular environment, and its involvement in regulating a wide range of cellular functions makes it especially vital to cellular homeostasis. Its critical role is not limited to healthy cells, it is also involved in cancer development, and is overexpressed in many cancers. This makes the thioredoxin system a promising target for cancer drug development. As such, over the last decade, many inhibitors have been developed that target the thioredoxin system, most of which are small molecules targeting the thioredoxin reductase C-terminal redox center. A few inhibitors of thioredoxin have also been developed. We believe that more efforts should be invested in developing protein/peptide-based inhibitors against both thioredoxin reductase and/or thioredoxin.

Therapeutic potentials of curcumin in the treatment of non-small-cell lung carcinoma

Non-small-cell lung carcinoma (NSCLC) is one of the most lethal malignancies that include more than 80% of lung cancer cases worldwide. During the past decades, plants and plant-derived products have attracted great interest in the treatment of various human diseases. Curcumin, the turmeric isolated natural phenolic compound, has shown a promising chemo-preventive and anticancer agent. Numerous studies have shown that curcumin delays the initiation and progression of NSCLC by affecting a wide range of molecular targets and cell signalling pathways including NF-kB, Akt, MAPKS, BCL-2, ROS and microRNAs (miRNAs). However, the poor oral bioavailability and low chemical stability of curcumin remain as major challenges in the utilisation of this compound as a therapeutic agent. Different analogs of curcumin and new delivery systems (e.g., micelles, nanoparticles and liposomes) provided promising solutions to overcome these obstacles and improve curcumin pharmacokinetic profile. The present review focuses on current reported studies about anti-NSCLC effects of curcumin. NSCLC involved miRNAs whose expression is regulated by curcumin has also been discussed. Furthermore, recent researches on the use of curcumin analogs and delivery systems to enhance the curcumin benefits in NSCLC are also described.

Diarylpentanoids with antitumor activity: A critical review of structure-activity relationship studies

Diarypentanoids are commonly considered as monocarbonyl analogues of curcumin. Since the discovery of this compound in 1962, twenty one diarylpentanoids have been isolated and almost 600 synthetic analogues with antitumor activity have been synthesized. This review reports the exploitation of diarylpentanoids to develop curcumin analogues with improved antitumor activity over the last two decades. The mechanism of action and structure-activity relationship (SAR) studies are also highlighted. More importantly, structural features for the antitumor activity that may guide the design of new and more effective diarylpentanoids are also proposed.

Two telomerase-targeting Pt(ii) complexes of jatrorrhizine and berberine derivatives induce apoptosis in human bladder tumor cells

Two novel Pt(ii) complexes, [Pt(B-TFA)Cl]Cl (Pt1) and [Pt(J-TFA)Cl]Cl (Pt2) with jatrorrhizine and berberine derivatives (B-TFA and J-TFA) were first prepared as desirable luminescent agents for cellular applications and potent telomerase inhibitors, which can induce bladder T-24 tumor cell apoptosis by targeting telomerase, together with induction of mitochondrial dysfunction, telomere DNA damage and cell-cycle arrest. Importantly, T-24 tumor inhibition rate (TIR) was 50.4% for Pt2, which was higher than that of Pt1 (26.4%) and cisplatin (37.1%). Taken together, all the results indicated that jatrorrhizine and berberine derivatives Pt1 and Pt2 show low toxicity and could be novel Pt-based anti-cancer drug candidates.

Aminosalicylic acid reduces ER stress and Schwann cell death induced by MPZ mutations

Mutations in myelin protein zero (MPZ) cause inherited peripheral neuropathies, including Charcot‑Marie‑Tooth disease (CMT) and Dejerine‑Sottas neuropathy. Mutant MPZ proteins have previously been reported to cause CMT via enhanced endoplasmic reticulum (ER) stress and Schwann cell (SC) death, although the pathological mechanisms have not yet been elucidated. In this study, we generated an in vitro model of rat SCs expressing mutant MPZ (MPZ V169fs or R98C) proteins and validated the increase in cell death and ER stress induced by the overexpression of the MPZ mutants. Using this model, we examined the efficacy of 3 different aminosalicylic acids (ASAs; 4‑ASA, sodium 4‑ASA and 5‑ASA) in alleviating pathological phenotypes. FACS analysis indicated that the number of apoptotic rat SCs, RT4 cells, induced by mutant MPZ overexpression was significantly reduced following treatment with each ASA. In particular, treatment with 4‑ASA reduced the levels of ER stress markers in RT4 cells induced by V169fs MPZ mutant overexpression and relieved the retention of V169fs mutant proteins in the ER. Additionally, the level of an apoptotic signal mediator (p‑JNK) was only decreased in the RT4 cells expressing R98C MPZ mutant protein following treatment with 4‑ASA. Although 4‑ASA is known as a free radical scavenger, treatment with 4‑ASA in the in vitro model did not moderate the level of reactive oxygen species, which was elevated by the expression of mutant MPZ proteins. On the whole, the findings of this study indicate that treatment with 4‑ASA reduced the ER stress and SC death caused by 2 different MPZ mutants and suggest that ASA may be a potential therapeutic agent for CMT.

Discovery of high in vitro and in vivo antitumor activities of organometallic ruthenium(ii)–arene complexes with 5,7-dihalogenated-2-methyl-8-quinolinol

MClClQ-RuCl induced HeLa cell apoptosis was mediated by the inhibition of telomerase activity and dysfunction of mitochondria. Remarkably, MClClQ-RuCl obviously inhibited HeLa xenograft tumor growth in vivo.

In vitro and in vivo anti-tumor activity of two gold(III) complexes with isoquinoline derivatives as ligands

Two gold(III) complexes of isoquinoline derivatives: [Au(L¹)Cl₂] (Au1) and [Au(L²)Cl₂] (Au2) have been prepared and characterized. Au1 and Au2 exhibited greater cytotoxicity than their corresponding ligands and cisplatin against T-24 cells. Both complexes arrested cell cycle at S-phase by upregulation of p53, p27, and p21, and downregulation of cyclin A and cyclin E. The depolarization of the mitochondrial membrane potential, generation of ROS, and stimulated Ca²⁺ release activated the caspase cascade and ultimately caused apoptosis by increasing the levels of Bax and Bak, and decreasing the levels of Bcl-2 and Bcl-xl. Cell apoptosis was achieved via mitochondria mediated pathways. The in vivo studies of Au1 and Au2 demonstrated that they were safer than cisplatin and could effectively inhibit tumor growth.

Selective killing of gastric cancer cells by a small molecule via targeting TrxR1 and ROS-mediated ER stress activation

The thioredoxin reductase (TrxR) 1 is often overexpressed in numerous cancer cells. Targeting TrxR1 leads to a reduction in tumor progression and metastasis, making the enzyme an attractive target for cancer treatment. Our previous research revealed that the curcumin derivative B19 could induce cancer cell apoptosis via activation of endoplasmic reticulum (ER) stress. However, the upstream mechanism and molecular target of B19 is still unclear. In this study, we demonstrate that B19 directly inhibits TrxR1 enzyme activity to elevate oxidative stress and then induce ROS-mediated ER Stress and mitochondrial dysfunction, subsequently resulting in cell cycle arrest and apoptosis in human gastric cancer cells. A computer-assistant docking showed that B19 may bind TrxR1 protein via formation of a covalent bond with the residue Cys-498. Blockage of ROS production totally reversed B19-induced anti-cancer actions. In addition, the results of xenograft experiments in mice were highly consistent with in vitro studies. Taken together, targeting TrxR1 with B19 provides deep insight into the understanding of how B19 exerts its anticancer effects. More importantly, this work indicates that targeting TrxR1 and manipulating ROS levels are effective therapeutic strategy for the treatment of gastric cancer.

Curcumin inhibits hepatitis B virus infection by down-regulating cccDNA-bound histone acetylation

AIM

To investigate the potential effect of curcumin on hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and the underlying mechanism.

METHODS

A HepG2.2.15 cell line stably transfected with HBV was treated with curcumin, and HBV surface antigen (HBsAg) and e antigen (HBeAg) expression levels were assessed by ELISA. Intracellular HBV DNA replication intermediates and cccDNA were detected by Southern blot and real-time PCR, respectively. The acetylation levels of histones H3 and H4 were measured by Western blot. H3/H4-bound cccDNA was detected by chromatin immunoprecipitation (ChIP) assays. The deacetylase inhibitors trichostatin A and sodium butyrate were used to study the mechanism of action for curcumin. Additionally, short interfering RNAs (siRNAs) targeting HBV were tested along with curcumin.

RESULTS

Curcumin treatment led to time- and dose-dependent reductions in HBsAg and HBeAg expression and significant reductions in intracellular HBV DNA replication intermediates and HBV cccDNA. After treatment with 20 μmol/L curcumin for 2 d, HBsAg and cccDNA levels in HepG2.2.15 cells were reduced by up to 57.7% (P < 0.01) and 75.5% (P < 0.01), respectively, compared with levels in non-treated cells. Meanwhile, time- and dose-dependent reductions in the histone H3 acetylation levels were also detected upon treatment with curcumin, accompanied by reductions in H3- and H4-bound cccDNA. Furthermore, the deacetylase inhibitors trichostatin A and sodium butyrate could block the effects of curcumin. Additionally, transfection of siRNAs targeting HBV enhanced the inhibitory effects of curcumin.

CONCLUSION

Curcumin inhibits HBV gene replication via down-regulation of cccDNA-bound histone acetylation and has the potential to be developed as a cccDNA-targeting antiviral agent for hepatitis B.

Oxoaporphine Metal Complexes (CoII, NiII, ZnII) with High Antitumor Activity by Inducing Mitochondria-Mediated Apoptosis and S-phase Arrest in HepG2

Three new oxoaporphine Co(II), Ni(II) and Zn(II) complexes 1–3 have been synthesized and fully characterized. 1–3 have similar mononuclear structures with the metal and ligand ratio of 1:2. 1–3 exhibited higher cytotoxicity than the OD ligand and cisplatin against HepG2, T-24, BEL-7404, MGC80–3 and SK-OV-3/DDP cells, with IC₅₀ value of 0.23−4.31 μM. Interestingly, 0.5 μM 1–3 significantly caused HepG2 arrest at S-phase, which was associated with the up-regulation of p53, p21, p27, Chk1 and Chk2 proteins, and decrease in cyclin A, CDK2, Cdc25A, PCNA proteins. In addition, 1–3 induced HepG2 apoptosis via a caspase-dependent mitochondrion pathway as evidenced by p53 activation, ROS production, Bax up-regulation and Bcl-2 down-regulation, mitochondrial dysfunction, cytochrome c release, caspase activation and PARP cleavage. Furthermore, 3 inhibited tumor growth in HepG2 xenograft model, and displayed more safety profile in vivo than cisplatin.

In Silico Mining for Antimalarial Structure-Activity Knowledge and Discovery of Novel Antimalarial Curcuminoids

Malaria is a parasitic tropical disease that kills around 600,000 patients every year. The emergence of resistant Plasmodium falciparum parasites to artemisinin-based combination therapies (ACTs) represents a significant public health threat, indicating the urgent need for new effective compounds to reverse ACT resistance and cure the disease. For this, extensive curation and homogenization of experimental anti-Plasmodium screening data from both in-house and ChEMBL sources were conducted. As a result, a coherent strategy was established that allowed compiling coherent training sets that associate compound structures to the respective antimalarial activity measurements. Seventeen of these training sets led to the successful generation of classification models discriminating whether a compound has a significant probability to be active under the specific conditions of the antimalarial test associated with each set. These models were used in consensus prediction of the most likely active from a series of curcuminoids available in-house. Positive predictions together with a few predicted as inactive were then submitted to experimental in vitro antimalarial testing. A large majority from predicted compounds showed antimalarial activity, but not those predicted as inactive, thus experimentally validating the in silico screening approach. The herein proposed consensus machine learning approach showed its potential to reduce the cost and duration of antimalarial drug discovery.

The Curcumin Analog C-150, Influencing NF-κB, UPR and Akt/Notch Pathways Has Potent Anticancer Activity In Vitro and In Vivo

C-150 a Mannich-type curcumin derivative, exhibited pronounced cytotoxic effects against eight glioma cell lines at micromolar concentrations. Inhibition of cell proliferation by C-150 was mediated by affecting multiple targets as confirmed at transcription and protein level. C-150 effectively reduced the transcription activation of NFkB, inhibited PKC-alpha which are constitutively over-expressed in glioblastoma. The effects of C-150 on the Akt/ Notch signaling were also demonstrated in a Drosophila tumorigenesis model. C-150 reduced the number of tumors in Drosophila with similar efficacy to mitoxantrone. In an in vivo orthotopic glioma model, C-150 significantly increased the median survival of treated nude rats compared to control animals. The multi-target action of C-150, and its preliminary in vivo efficacy would render this curcumin analogue as a potent clinical candidate against glioblastoma.

Da0324, an inhibitor of nuclear factor-κB activation, demonstrates selective antitumor activity on human gastric cancer cells

Background

The transcription factor nuclear factor-κB (NF-κB) is constitutively activated in a variety of human cancers, including gastric cancer. NF-κB inhibitors that selectively kill cancer cells are urgently needed for cancer treatment. Curcumin is a potent inhibitor of NF-κB activation. Unfortunately, the therapeutic potential of curcumin is limited by its relatively low potency and poor cellular bioavailability. In this study, we presented a novel NF-κB inhibitor named Da0324, a synthetic asymmetric mono-carbonyl analog of curcumin. The purpose of this study is to research the expression of NF-κB in gastric cancer and the antitumor activity and mechanism of Da0324 on human gastric cancer cells.

Methods

The expressions between gastric cancer tissues/cells and normal gastric tissues/cells of NF-κB were evaluated by Western blot. The inhibition viability of compounds on human gastric cancer cell lines SGC-7901, BGC-823, MGC-803, and normal gastric mucosa epithelial cell line GES-1 was assessed with the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. Absorption spectrum method and high-performance liquid chromatography method detected the stability of the compound in vitro. The compound-induced changes of inducible NF-κB activation in the SGC-7901 and BGC-823 cells were examined by Western blot analysis and immunofluorescence methods. The antitumor activity of compound was performed by clonogenic assay, matrigel invasion assay, flow cytometric analysis, Western blot analysis, and Hoechst 33258 staining assay.

Results

High levels of p65 were found in gastric cancer tissues and cells. Da0324 displayed higher growth inhibition against several types of gastric cancer cell lines and showed relatively low toxicity to GES-1. Moreover, Da0324 was more stable than curcumin in vitro. Western blot analysis and immunofluorescence methods showed that Da0324 blocked NF-κB activation. In addition, Da0324 significantly inhibited tumor proliferation and invasion, arrested the cell cycle, and induced apoptosis in vitro.

Conclusion

The asymmetric mono-carbonyl analog of curcumin Da0324 exhibited significantly improved antigastric cancer activity. Da0324 may be a promising NF-κB inhibitor for the selective targeting of cancer cells. However, further studies are needed in animals to validate these findings for the therapeutic use of Da0324.

Discovery of New Monocarbonyl Ligustrazine-Curcumin Hybrids for Intervention of Drug-Sensitive and Drug-Resistant Lung Cancer

The elevation of oxidative stress preferentially in cancer cells by inhibiting thioredoxin reductase (TrxR) and/or enhancing reactive oxygen species (ROS) production has emerged as an effective strategy for selectively targeting cancer cells. In this study, we designed and synthesized 21 ligustrazine-curcumin hybrids (10a-u). Biological evaluation indicated that the most active compound 10d significantly inhibited the proliferation of drug-sensitive (A549, SPC-A-1, LTEP-G-2) and drug-resistant (A549/DDP) lung cancer cells but had little effect on nontumor lung epithelial-like cells (HBE). Furthermore, 10d suppressed the TrxR/Trx system and promoted intracellular ROS accumulation and cancer cell apoptosis. Additionally, 10d inhibited the NF-κB, AKT, and ERK signaling, P-gp-mediated efflux of rhodamine 123, P-gp ATPase activity, and P-gp expression in A549/DDP cells. Finally, 10d repressed the growth of implanted human drug-resistant lung cancer in mice. Together, 10d acts a novel TrxR inhibitor and may be a promising candidate for intervention of lung cancer.

3,3'-OH curcumin causes apoptosis in HepG2 cells through ROS-mediated pathway

In this paper, we synthesized a series of curcumin analogs and evaluated their cytotoxicity against HepG2 cells. The results exhibited that the hydroxyl group at 3,3'-position play an essential role in enhancing their anti-proliferation activity. More importantly, 3,3'-hydroxy curcumin (1b) caused apoptosis in HepG2 cells with the ROS generation, which may be mainly composed of hydroxyl radicals (HO) and H2O2. The more cytotoxic activity and ROS-generating ability of 1b may be due to the more stable in (RPMI)-1640 medium and more massive uptake than curcumin. Then the generation of ROS can disrupt the intracellular redox balance, induce lipid peroxidation, cause the collapse of the mitochondrial membrane potential and ultimately lead to apoptosis. The results not only suggest that 3,3'-hydroxy curcumin (1b) may cause HepG2 cells apoptosis through ROS-mediated pathway, but also offer an important information for design of curcumin analog.

Concentration gradient generator for H460 lung cancer cell sensitivity to resist the cytotoxic action of curcumin in microenvironmental pH conditions

We proposed and demonstrated a concentration gradient generator (CGG) to resist H460 lung cancer cells using curcumin in microenvironmental pH conditions.

Triazole linked mono carbonyl curcumin-isatin bifunctional hybrids as novel anti tubulin agents: Design, synthesis, biological evaluation and molecular modeling studies

Keeping in view the limitations associated with currently available anticancer drugs, molecular hybrids of mono carbonyl curcumin and isatin tethered by triazole ring have been synthesized and evaluated for in vitro cytotoxicity against THP-1, COLO-205, HCT-116, A549, HeLa, CAKI-I, PC-3, MiaPaca-2 human cancer cell lines. The results revealed that the compounds SA-1 to SA-9, SB-2, SB-3, SB-4, SB-7 and SC-2 showed a good range of IC50 values against THP-1, COLO-205, HCT-116 and PC-3 cell lines, while the other four cell lines among these were found to be almost resistant. Structure activity relationship revealed that the nature of Ring X and substitution at position R influences the activity. Methoxy substituted phenyl ring as Ring X and H as R were found to be the ideal structural features. The most potent compounds (SA-2, SA-3, SA-4, SA-7) were further tested for tubulin inhibition. Compound SA-2 was found to significantly inhibit the tubulin polymerization (IC50=1.2 μM against HCT-116). Compound SA-2, moreover, lead to the disruption of microtubules as confirmed by immunofluorescence technique. The significant cytotoxicity and tubulin inhibition by SA-2 was streamlined by molecular modeling studies where it was docked at the curcumin binding site of tubulin.

Insights into the importance for designing curcumin-inspired anticancer agents by a prooxidant strategy: The case of diarylpentanoids

Developing anticancer agents by a prooxidant strategy has attracted increasing attention in recent years, although it is not conventional in medicinal chemistry and is completely opposite to antioxidant therapy. In this work, a panel of diarylpentanoids as the curcumin mono-carbonyl analogs were designed and synthesized, and their cytotoxic and proapoptotic mechanisms against human lung cancer A549 cells were investigated at the frontiers of chemistry and biology. It was found that compared with curcumin, the compounds (A1, B1, and C1) bearing two ortho substituents on the aromatic rings, especially A1, exhibit significantly increased cytotoxic and proapoptotic activities through a Michael acceptor unit-dependent prooxidant-mediated mechanism. The prooxidative ability is governed not only by their electrophilicity but also by their geometry, cellular uptake and metabolic stability, and TrxR-inhibitory activity. Mechanistic investigation reveals that the compound A1 could effectively and irreversibly modify the TrxR by virtue of the above optimal biochemical parameters, and convert this antioxidant enzyme into a reactive oxygen species (ROS) promoter, resulting in a burst of the intracellular ROS including H2O2 and O2(-)•. The ROS generation is associated with falling apart in the redox buffering system, and subsequently induces increases in Ca(2+) influx and oxidative stress, collapse of mitochondrial membrane potential, and activation of caspase-9 and caspase-3, ultimately leading to cell apoptosis. This work highlights the feasibility in designing curcumin-inspired anticancer agents by a prooxidant strategy, and gives us useful information on how to design them.

Identification of 5-nitrofuran-2-amide derivatives that induce apoptosis in triple negative breast cancer cells by activating C/EBP-homologous protein expression

The transcription factor C/EBP-homologous protein (CHOP) is a key component of the terminal unfolded protein response (UPR) that mediates unresolvable endoplasmic reticulum stress-induced apoptosis. CHOP induction is known to cause cancer cell death. Chemicals that induce CHOP expression would thus be valuable as potential cancer therapeutics and as research tools. Here, we identified 5-nitrofuran-2-amide derivatives as small molecule activators of CHOP expression that induced apoptosis in triple negative breast cancer (TNBC) cells. Our preliminary structure-activity relationship studies indicated that compounds with an N-phenyl-5-nitrofuran-2-carboxamide skeleton were particularly potent inducers of TNBC cell apoptosis. The compounds activate CHOP expression via the PERK-eIF2α-ATF4 branch of the UPR. These results indicate that small molecule activators of CHOP expression may have therapeutic potential for TNBC.

Curcumin analogue A501 induces G2/M arrest and apoptosis in non-small cell lung cancer cells

Curcumin and its analogues have been reported to exert anti-cancer activity against a variety of tumors. Here, we reported A501, a new curcumin analogue. The effect of A501 on cell viability was detected by MTT assay, the result showed that A501 had a better inhibiting effect on the four non-small cell lung cancer (NSCLC) cells than that of curcumin. Moreover, Colony forming experiment showed A501 significant restrained cell proliferation. Flow cytometry displayed A501 can cause G2/M arrest and induce apoptosis. Western blotting showed that A501 decreased the expression of cyclinB1, cdc-2, bcl-2, while increased the expression of p53, cleaved caspase-3 and bax. In conclusion, curcumin analogues A501 played antitumor activity by inhibiting cell proliferation and inducing apoptosis of NSCLC cells. And it was likely to be a promising starting point for the development of curcumin-based anticancer drugs.

Water-Soluble Ruthenium(II) Complexes with Chiral 4-(2,3-Dihydroxypropyl)-formamide Oxoaporphine (FOA): In Vitro and in Vivo Anticancer Activity by Stabilization of G-Quadruplex DNA, Inhibition of Telomerase Activity, and Induction of Tumor Cell Apoptosis

Three water-soluble ruthenium(II) complexes with chiral 4-(2,3-dihydroxypropyl)-formamide oxoaporphine (FOA) were synthesized and characterized. It was found that these ruthenium(II) complexes exhibited considerable in vitro anticancer activities and that they were the effective stabilizers of telomeric and G-quadruplex-DNA (G4-DNA) in promoter of c-myc, which acted as a telomerase inhibitor targeting G4-DNA and induced cell senescence and apoptosis. Interestingly, the in vitro anticancer activity of 6 (LC-003) was higher than those of 4 (LC-001) and 5 (LC-002), more selective for BEL-7404 cells than for normal HL-7702 cells, and preferred to activate caspases-3/9. The different biological behaviors of the ruthenium complexes could be correlated with the chiral nature of 4-(2,3-dihydroxypropyl)-formamide oxoaporphine. More significantly, 6 exhibited effective inhibitory on tumor growth in BEL-7402 xenograft mouse model and higher in vivo safety than cisplatin. These mechanistic insights indicate that 6 displays low toxicity and can be a novel anticancer drug candidate.

Anti-Lung Cancer Activity of the Curcumin Analog JZ534 In Vitro

This study investigated the anticancer effect of the curcumin analog JZ534 on lung cancer cell lines H460, A549, H1975, and HCC827. The antiproliferation effect of JZ534 was measured through the methylthiazoletetrazolium assay, and cell colony formation was observed. Cell cycle and apoptosis were determined by flow cytometry, and the preliminary mechanism was studied by Western blot. Results showed that JZ534 significantly inhibited the vitality and colony formation of lung cancer cells. JZ534 induced the G2/M cell cycle arrest of the cancer cells and suppressed the expression of cycle-related proteins, including cyclin B1 and Cdc2. Meanwhile, JZ534 induced cell apoptosis and upregulated the expression of apoptosis-related proteins, including cleaved caspase-3, Bax, and p53. At the same dose, JZ534 showed better antitumor activity than curcumin. These results suggest that JZ534 exhibits excellent anti-lung cancer activity by inhibiting the growth and inducing the apoptosis of lung cancer cells. Therefore, JZ534 is a promising lead compound for cancer treatment.

Water-soluble oxoglaucine-Y(iii), Dy(iii) complexes: in vitro and in vivo anticancer activities by triggering DNA damage, leading to S phase arrest and apoptosis

The complexes exhibited considerable in vitro and in vivo anticancer activity, and higher safety than ciplatin.

Eliminating the heart from the curcumin molecule: monocarbonyl curcumin mimics (MACs)

Curcumin is a natural product with several thousand years of heritage. Its traditional Asian application to human ailments has been subjected in recent decades to worldwide pharmacological, biochemical and clinical investigations. Curcumin’s Achilles heel lies in its poor aqueous solubility and rapid degradation at pH ~ 7.4. Researchers have sought to unlock curcumin’s assets by chemical manipulation. One class of molecules under scrutiny are the monocarbonyl analogs of curcumin (MACs). A thousand plus such agents have been created and tested primarily against cancer and inflammation. The outcome is clear. In vitro, MACs furnish a 10–20 fold potency gain vs. curcumin for numerous cancer cell lines and cellular proteins. Similarly, MACs have successfully demonstrated better pharmacokinetic (PK) profiles in mice and greater tumor regression in cancer xenografts in vivo than curcumin. The compounds reveal limited toxicity as measured by murine weight gain and histopathological assessment. To our knowledge, MAC members have not yet been monitored in larger animals or humans. However, Phase 1 clinical trials are certainly on the horizon. The present review focuses on the large and evolving body of work in cancer and inflammation, but also covers MAC structural diversity and early discovery for treatment of bacteria, tuberculosis, Alzheimer’s disease and malaria.

Synthesis and biological evaluation of novel indole-2-one and 7-aza-2-oxindole derivatives as anti-inflammatory agents

Sepsis, a typically acute inflammatory disease, is the biggest cause of death in ICU (intensive care unit). Novel anti-inflammatory alternatives are still in urgent need. In this study, we designed and synthesized 30 indole-2-one and 7-aza-2-oxindole derivatives based on the skeleton of tenidap, and their anti-inflammatory activity was determined by evaluating the inhibitory potency against lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF)-α and interleukin (IL)-6 release in RAW264.7 macrophages. Quantitative SAR (structure-activity relationship) analysis revealed that a high molecular polarizability and low lipid/water partition coefficient (ALogP) in indole-2-one are beneficial for anti-inflammatory activity. Moreover, compounds 7i and 8e inhibited the expression of TNF-α, IL-6, COX-2, PGES, and iNOS in LPS-stimulated macrophages, and 7i exhibited a significant protection from LPS-induced septic death in mouse models. These data present a series of new indole-2-one compounds with potential therapeutic effects in acute inflammatory diseases.

A monocarbonyl analogue of curcumin, 1,5-bis(3-hydroxyphenyl)-1,4-pentadiene-3-one (Ca 37), exhibits potent growth suppressive activity and enhances the inhibitory effect of curcumin on human prostate cancer cells

Prostate carcinoma is one of the leading causes of cancer-related morbidity and mortality in males in western countries. Curcumin exhibits growth-suppressive activity against several cancers, including prostate cancer, but it has poor bioavailability. The purpose of this study was to evaluate the anticancer potency and mechanism of a curcumin analogue, 1,5-bis(3-hydroxyphenyl)-1,4-pentadiene-3-one (Ca 37), in human prostate cancer. Studies were performed in established human prostate cancer cell lines (PC-3 and DU145) as well as in a murine xenograft tumor (PC-3) model. Ca 37 presented a preferential suppression capacity against growth and migration toward prostate cancer cells compared with curcumin. Ca 37 impaired the bioenergetics system, promoted cell cycle arrest and apoptosis activation in PC-3 cells. In addition, 0.5 μmol (6.65 mg/kg body weight) of Ca 37 significantly inhibited the growth of the prostate xenografted tumors, whereas 6 μmol (110 mg/kg body weight) of curcumin had little effect. Furthermore, a combination of Ca 37 and curcumin resulted in enhanced antitumor activity in prostate cancer cells. N-Acetylcysteine abrogated both reactive oxygen species (ROS) production and viability loss induced by Ca 37 but partially prevented growth inhibition in PC-3 cells treated with curcumin alone, or a combination with Ca 37. The data indicate that induction of ROS plays a vital role in the growth inhibitory effect of Ca 37 in PC-3 cells. This study suggests that Ca 37, alone or in combination with curcumin, may be a promising anticancer agent for prostate cancer therapy.

Synthesis and evaluation of bisbenzylidenedioxotetrahydrothiopranones as activators of endoplasmic reticulum (ER) stress signaling pathways and apoptotic cell death in acute promyelocytic leukemic cells

Curcumin is known to trigger ER-stress induced cell death of acute promyelocytic leukemic (APL) cells by intercepting the degradation of nuclear co-repressor (N-CoR) protein which has a key role in the pathogenesis of APL. Replacing the heptadienedione moiety of curcumin with a monocarbonyl cross-conjugated dienone embedded in a tetrahydrothiopyranone dioxide ring resulted in thiopyranone dioxides that were more resilient to hydrolysis and had greater growth inhibitory activities than curcumin on APL cells. Several members intercepted the degradation of misfolded N-CoR and triggered the signaling cascade in the unfolded protein response (UPR) which led to apoptotic cell death. Microarray analysis showed that genes involved in protein processing pathways that were germane to the activation of the UPR were preferentially up-regulated in treated APL cells, supporting the notion that the UPR was a consequential mechanistic pathway affected by thiopyranone dioxides. The Michael acceptor reactivity of the scaffold may have a role in exacerbating ER stress in APL cells.

The molecular basis for the pharmacokinetics and pharmacodynamics of curcumin and its metabolites in relation to cancer

This review addresses the oncopharmacological properties of curcumin at the molecular level. First, the interactions between curcumin and its molecular targets are addressed on the basis of curcumin's distinct chemical properties, which include H-bond donating and accepting capacity of the β-dicarbonyl moiety and the phenylic hydroxyl groups, H-bond accepting capacity of the methoxy ethers, multivalent metal and nonmetal cation binding properties, high partition coefficient, rotamerization around multiple C-C bonds, and the ability to act as a Michael acceptor. Next, the in vitro chemical stability of curcumin is elaborated in the context of its susceptibility to photochemical and chemical modification and degradation (e.g., alkaline hydrolysis). Specific modification and degradatory pathways are provided, which mainly entail radical-based intermediates, and the in vitro catabolites are identified. The implications of curcumin's (photo)chemical instability are addressed in light of pharmaceutical curcumin preparations, the use of curcumin analogues, and implementation of nanoparticulate drug delivery systems. Furthermore, the pharmacokinetics of curcumin and its most important degradation products are detailed in light of curcumin's poor bioavailability. Particular emphasis is placed on xenobiotic phase I and II metabolism as well as excretion of curcumin in the intestines (first pass), the liver (second pass), and other organs in addition to the pharmacokinetics of curcumin metabolites and their systemic clearance. Lastly, a summary is provided of the clinical pharmacodynamics of curcumin followed by a detailed account of curcumin's direct molecular targets, whereby the phenotypical/biological changes induced in cancer cells upon completion of the curcumin-triggered signaling cascade(s) are addressed in the framework of the hallmarks of cancer. The direct molecular targets include the ErbB family of receptors, protein kinase C, enzymes involved in prostaglandin synthesis, vitamin D receptor, and DNA.

Evaluation of a curcumin analog as an anti-cancer agent inducing ER stress-mediated apoptosis in non-small cell lung cancer cells

BACKGROUND

Recent advances have highlighted the importance of the endoplasmic reticulum (ER) in cell death processes. Pharmacological interventions that effectively enhance tumor cell death through activating ER stress have attracted a great deal of attention for anti-cancer therapy.

METHODS

A bio-evaluation on 113 curcumin analogs against four cancer cell lines was performed through MTT assay. Furthermore, real time cell assay and flow cytometer were used to evaluate the apoptotic induction of (1E,4E)-1,5-bis(5-bromo-2-ethoxyphenyl)penta-1,4-dien-3-one (B82). Western blot, RT-qPCR, and siRNA were then utilized to confirm whether B82-induced apoptosis is mediated through activating ER stress pathway. Finally, the in vivo anti-tumor effect of B82 was evaluated.

RESULTS

B82 exhibited strong anti-tumor activity in non-small cell lung cancer (NSCLC) H460 cells. Treatment with B82 significantly induced apoptosis in H460 cells in vitro and inhibited H460 tumor growth in vivo. Further studies demonstrated that the B82-induced apoptosis is mediated by activating ER stress both in vitro and in vivo.

CONCLUSIONS

A new monocarbonyl analog of curcumin, B82, exhibited anti-tumor effects on H460 cells via an ER stress-mediated mechanism. B82 could be further explored as a potential anticancer agent for the treatment of NSCLC.