Synthesis and assessment of the antioxidant and antitumor properties of asymmetric curcumin analogues

Anticancer perspectives of monocarbonyl analogs of curcumin: A decade (2014-2024) review

Monocarbonyl analogs of curcumin (MACs) represent structurally modified versions of curcumin. The existing literature indicates that MACs exhibit enhanced anticancer properties compared with curcumin. Numerous research articles in recent years have emphasized the significance of MACs as effective anticancer agents. This review focuses on the latest advances in the anticancer potential of MACs, from 2014 to 2024, including discussions on their mechanism of action, structure-activity relationship (SAR), and in silico molecular docking studies.

Effects of curcumin and ursolic acid in prostate cancer: A systematic review

The major barriers to phytonutrients in prostate cancer therapy are non-specific mechanisms and bioavailability issues. Studies have pointed to a synergistic combination of curcumin (CURC) and ursolic acid (UA). We investigate this combination using a systematic review process to assess the most likely mechanistic pathway and human testing in prostate cancer. We used the PRISMA statement to screen titles, abstracts, and the full texts of relevant articles and performed a descriptive analysis of the literature reviewed for study inclusion and consensus of the manuscript. The most common molecular and cellular pathway from articles reporting on the pathways and effects of CURC (n = 173) in prostate cancer was NF-κB (n = 25, 14.5%). The most common molecular and cellular pathway from articles reporting on the pathways and effects of UA (n = 24) in prostate cancer was caspase 3/caspase 9 (n = 10, 41.6%). The three most common molecular and cellular pathway from articles reporting on the pathways and effects of both CURC and UA (n = 193) in prostate cancer was NF-κB (n = 28, 14.2%), Akt (n = 22, 11.2%), and androgen (n = 19, 9.6%). Therefore, we have identified the potential synergistic target pathways of curcumin and ursolic acid to involve NF-κB, Akt, androgen receptors, and apoptosis pathways. Our review highlights the limited human studies and specific effects in prostate cancer.

Nanoarchitectonics of the Effects of Curcumin Carbon Dot-Decorated Chitosan Nanoparticles on Proliferation and Apoptosis-Related Gene Expressions in HepG2 Hepatocellular Carcinoma Cells

This study examines the potential anticancer properties of curcumin carbon nanodot-decorated chitosan nanoparticles (CCM@CD/CS-NP) in HepG2 hepatocellular carcinoma cells. CCM@CD/CS-NPs were synthesized, and their size, morphology, and elemental analysis were characterized. The combination of curcumin carbon dots and chitosan in the form of a nanoparticle has a number of benefits, including improved solubility and bioavailability of curcumin, enhanced stability and biocompatibility of carbon dots, and sustained release of the drug due to the mucoadhesive properties of chitosan. The purpose of this research was to examine the efficacy of curcumin carbon dot-decorated chitosan nanoparticles as an anticancer agent in the treatment of HepG2 cell lines. The cell proliferation and apoptosis-related gene expressions in HepG2 cells were assessed to investigate the potential use of nanoparticles in vitro. The IC50 value for the inhibitory effect of CCM@CD/CS-NPs on cell growth and proliferation was determined to be 323.61 μg/mL at 24 h and 267.73 μg/mL at 48 h. Increased caspase-3 and -9 activation shows that CCM@CD/CS-NPs promoted apoptosis in HepG2 cells. It was also shown that the overexpression of Bax and the downregulation of Bcl-2 were responsible for the apoptotic impact of CCM@CD/CS-NPs. The nanoparticles have been shown to have minimal toxicity to normal liver cells, indicating their potential as a safe and effective treatment for HepG2. These novel nanomaterials effectively suppressed tumor development and boosted the rate of apoptotic cell death.

A Review: Exploring Synthetic Schemes and Structure-activity Relationship (SAR) Studies of Mono-carbonyl Curcumin Analogues for Cytotoxicity Inhibitory Anticancer Activity

INTRODUCTION

Cancer is the major cause of death globally. Cancer can be treated with naturally occurring Curcumin nuclei. Curcumin has a wide range of biological actions, including anti-inflammatory and anti-cancer properties. Even though it is an effective medicinal entity, it has some limitations such as instability at physiological pH and a weak pharmacokinetic profile due to the β-diketone moiety present in it. To overcome this drawback, research was carried out on monoketone moieties in curcumin, popularly known as mono-carbonyl curcumin.

OBJECTIVE

The present review focuses on different synthetic schemes and Mono-carbonyl curcumin derivative's Structure-Activity Relationship (SAR) as a cytotoxic inhibitory anticancer agent. The various synthetic schemes published by researchers were compiled.

METHODS

Findings of different researchers working on mono-carbonyl curcumin as an anticancer have been reviewed, analyzed and the outcomes were summarized.

RESULTS

The combination of all of these approaches serves as a one-stop solution for mono-carbonyl curcumin synthesis. The important groups on different positions of mono-carbonyl curcumin were discovered by a SAR study focused on cytotoxicity, which could be useful in the designing of its derivatives.

CONCLUSION

Based on our examination of the literature, we believe that this review will help researchers design and develop powerful mono-carbonyl curcumin derivatives that can be proven essential for anticancer activity.

Modified Curcumins as Potential Drug Candidates for Breast Cancer: An Overview

Breast cancer (BC), the most common malignancy in women, results from significant alterations in genetic and epigenetic mechanisms that alter multiple signaling pathways in growth and malignant progression, leading to limited long-term survival. Current studies with numerous drug therapies have shown that BC is a complex disease with tumor heterogeneity, rapidity, and dynamics of the tumor microenvironment that result in resistance to existing therapy. Targeting a single cell-signaling pathway is unlikely to treat or prevent BC. Curcumin (a natural yellow pigment), the principal ingredient in the spice turmeric, is well-documented for its diverse pharmacological properties including anti-cancer activity. However, its clinical application has been limited because of its low solubility, stability, and bioavailability. To overcome the limitation of curcumin, several modified curcumin conjugates and curcumin mimics were developed and studied for their anti-cancer properties. In this review, we have focused on the application of curcumin mimics and their conjugates for breast cancer.

Bioactive Diarylpentanoids: Insights into the Biological Effects beyond Antitumor Activity and Structure-Activity Relationships

Diarylpentanoids, a class of natural products and their synthetic analogs which are structurally related to chalcones, have gained increasing attention due to their wide array of biological activities, including antitumor, anti-infective, antioxidant, anti-inflammatory, antidiabetic, anti-hyperuricemic, and neuroprotective properties. Previously, we reviewed diarylpentanoids with promising antitumor activity. However, in view of the wide range of biological activities described for this class of compounds, the purpose of this review is to provide a more detailed overview of the synthetic bioactive diarylpentanoids that have been described over the last two decades, beyond simply their antitumor effects. A total of 745 compounds were found, highlighting the main synthetic methodologies used in their synthesis as well as the structure-activity relationship studies and structural features for all activities reported. Collectively, this review highlights the diarylpentanoid scaffold as a promising starting point for the development of new therapeutic agents.

Click synthesis of novel dendronized curcumin and analogs. Strengthening of physicochemical properties toward biological applications

Curcumin and its analogs, chalcones, and C5-monocarbonyl are molecules of great therapeutic potential, but their poor stability and hydrophobicity have hampered their extensive use in clinical trials. Therefore, significant efforts have been made in materials science to improve their physicochemical properties. In this study, we propose dendronization as a synthetic strategy to strengthen some physicochemical properties such as solubility and stability of curcumin and analogs, taking advantage of the click chemistry (CuAAC) to attach second-generation polyester dendrons to the unsaturated cores. The dendronization, with the subsequent formation of aromatic triazole groups as linkers, not only modified the solubility and stability of the molecular systems but also favored the diketo tautomeric form of curcumin, as demonstrated spectroscopically. This result is significant since the diketo tautomer, which preserves the antioxidant properties of curcumin, is the most biologically active form. The hydrophobic/hydrophilic balance, achieved after dendronization, allowed the solubilization of the chromophoric molecules in buffered solutions at relevant pH values (7.4 and 6.4). Furthermore, the stability of all molecules was also upgraded since UV-vis absorption spectra did not exhibit modified profiles after 7 days at physiologic pH. From photochemical stability experiments irradiating at 415 nm, the dendritic derivatives containing triazole linkers were more susceptible to being degraded. All derivatives exhibited emission properties according to the length of each conjugate fragment. Fluorescence experiments evidenced the role of dendrons in preventing emission quenching by aggregation and exhibited differentiated emission behavior depending on the linker type (triazole or ester) between the chromophoric core and the polyester dendrons.

Synthesis and bio-properties of 4-piperidone containing compounds as curcumin mimics

3,5-Diyliden-4-piperidone scaffold are considered as curcumin mimic exhibiting diverse bio-properties.

The Effects of Curcumin Nanoparticles Incorporated into Collagen-Alginate Scaffold on Wound Healing of Skin Tissue in Trauma Patients

Wound healing is a biological process that is mainly crucial for the rehabilitation of injured tissue. The incorporation of curcumin (Cur) into a hydrogel system is used to treat skin wounds in different diseases due to its hydrophobic character. In this study, sodium alginate and collagen, which possess hydrophilic, low toxic, and biocompatible properties, were utilized. Collagen/alginate scaffolds were synthesized, and nanocurcumin was incorporated inside them; their interaction was evaluated by FTIR spectroscopy. Morphological studies investigated structures of the samples studied by FE-SEM. The release profile of curcumin was detected, and the cytotoxic test was determined on the L929 cell line using an MTT assay. Analysis of tissue wound healing was performed by H&E staining. Nanocurcumin was spherical, its average particle size was 45 nm, and the structure of COL/ALG scaffold was visible. The cell viability of samples was recorded in cells after 24 h incubation. Results of in vivo wound healing remarkably showed CUR-COL/ALG scaffold at about 90% (p < 0.001), which is better than that of COL/ALG, 80% (p < 0.001), and the control 73.4% (p < 0.01) groups at 14 days/ The results of the samples’ FTIR indicated that nanocurcumin was well-entrapped into the scaffold, which led to improving the wound-healing process. Our results revealed the potential of nanocurcumin incorporated in COL/ALG scaffolds for the wound healing of skin tissue in trauma patients.

Curcumin: From a controversial "panacea" to effective antineoplastic products

BACKGROUND

Curcumin, a controversial "panacea," has been broadly studied. Its bioactivities including antioxidant, anti-inflammatory, and especially antineoplastic activities have been documented. However, due to its extensive bioactivities, some scientists hold a skeptical point of view toward curcumin and described curcumin as a "deceiver" to chemists. The objective of this study was to explore curcumin's another possibility as a potential supplementary leading compound to cancer treatments.

METHODS

Literature searches were conducted using electronic databases. Search terms such as "curcumin," "curcumin analogues," and so on were used. The literatures were collected and summarized. In this article, reported targets of curcumin are reviewed. The limitations of a curcumin as a therapeutic anticancer product including low bioavailability and poor targeting are mentioned. Furthermore, modified curcumin analogues and antitumor mechanisms are listed and discussed in the aspects of cell death and tumor microenvironment including angiogenesis, tissue hypoxia status, and energy metabolism.

RESULTS

Several possible modification strategies were presented by analyzing the relationships between the antitumor activity of curcumin analogues and their structural characteristics, including the introduction of hydrophilic group, shortening of redundant hydrocarbon chain, the introduction of extra chemical group, and so on.

CONCLUSIONS

From our perspective, after structural modification curcumin could be more effective complementary product for cancer therapies by the enhancement of targeting abilities and the improvement of bioavailability.

Insights on the synthesis of asymmetric curcumin derivatives and their biological activities

Curcumin is a small organic molecule with pleiotropic biological activities. However, its multiple structural-pharmacokinetic challenges prevent its development into a clinical drug. Various structural modifications have been made to improve its drug profile. In this review, we focus on the methods adopted in the synthesis of asymmetric curcumin derivatives and their biological activities and forecast the future of this exciting class of compounds in the field of medicine.

Effects of green synthesised silver nanoparticles (ST06-AgNPs) using curcumin derivative (ST06) on human cervical cancer cells (HeLa) in vitro and EAC tumor bearing mice models

Background

In recent years, green synthesized silver nanoparticles have been increasingly investigated for their anti-cancer potential. In the present study, we aimed at the biosynthesis of silver nanoparticles (AgNPs) using a curcumin derivative, ST06. Although, the individual efficacies of silver nanoparticles or curcumin derivatives have been studied previously, the synergistic cytotoxic effects of curcumin derivative and silver nanoparticles in a single nanoparticulate formulation have not been studied earlier specifically on animal models. This makes this study novel compared to the earlier synthesized curcumin derivative or silver nanoparticles studies. The aim of the study was to synthesize ST06 coated silver nanoparticles (ST06-AgNPs) using ST06 as both reducing and coating agent.

Methods

The synthesized nanoparticles AgNPs and ST06-AgNPs were characterised for the particle size distribution, morphology, optical properties and surface charge by using UV-visible spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM). Elemental composition and structural properties were studied by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction spectroscopy (XRD). The presence of ST06 as capping agent was demonstrated by Fourier transform infrared spectroscopy (FTIR).

Results

The synthesized nanoparticles (ST06-AgNPs) were spherical and had a size distribution in the range of 50–100 nm. UV-Vis spectroscopy displayed a specific silver plasmon peak at 410 nm. The in vitro cytotoxicity effects of ST06 and ST06-AgNPs, as assessed by MTT assay, showed significant growth inhibition of human cervical cancer cell line (HeLa). In addition, studies carried out in EAC tumor-induced mouse model (Ehrlich Ascites carcinoma) using ST06-AgNPs, revealed that treatment of the animals with these nanoparticles resulted in a significant reduction in the tumor growth, compared to the control group animals.

Conclusion

In conclusion, green synthesized ST06-AgNPs exhibited superior anti-tumor efficacy than the free ST06 or AgNPs with no acute toxicity under both in vitro and in vivo conditions. The tumor suppression is associated with the intrinsic apoptotic pathway. Together, the results of this study suggest that ST06-AgNPs could be considered as a potential option for the treatment of solid tumors.

Developments in the anticancer activity of structurally modified curcumin: An up-to-date review

Curcumin is a pharmacologically active polyphenol derived from the popular spice element-Turmeric. The therapeutic activity of curcumin has been extensively investigated over the last few decades and reports suggest the role of curcumin in a large number of biological activities, particularly its prominent anticancer activity. Curcumin, being a pleiotropic molecule, is a regulator of multiple molecular targets which play crucial roles in various cell signaling pathways. It is known to suppress transformation, inhibit proliferation as well as induce apoptosis. However, despite all these benefits, the efficacy of curcumin remains limited due to its poor bioavailability, poor absorption within the systemic circulation and rapid elimination from the body. To overcome these limiting factors, researchers all around the world are working towards designing a synthetic and superior curcuminoid by making suitable structural modifications to the parent skeleton. These curcuminoids, mainly analogues and derivatives, will not only improve the physicochemical properties but also enhance the efficacy simultaneously. The present review will provide a comprehensive account of the analogues and derivatives of curcumin that have been reported since 2014 which have indicated a better anticancer activity than curcumin.

Protonation of Curcumin Triggers Sequential Double Cyclization in the Gas-Phase: An Electrospray Mass Spectrometry and DFT Study

ESI-protonated natural curcumin (1) undergoes gas-phase cyclization and dissociates via competitive expulsions of 2-methoxy phenol and C₄H₄O₂ (diketene or an isomer). Evidence from mechanistic mass spectrometry and from Density Functional Theory (DFT) reveals that a two-step sequential cyclization occurs for the protonated molecule prior to the unusual loss of the elements of 2-methoxy phenol. Furthermore, the presence of the methoxy group at postion-3 is essential for the second cyclization. The transformation of curcumin upon protonation in the gas phase may be predictive of its solution chemistry and explain how curcumin plays a protective role in biology.

Curcumin analogues attenuate Aβ25-35-induced oxidative stress in PC12 cells via Keap1/Nrf2/HO-1 signaling pathways

Beta-amyloid (Aβ) has pivotal functions in the pathogenesis of Alzheimer's Disease (AD). In the present study, we adopted an vitro model that involved Aβ_25-35-induced oxidative damage in PC12 cells. Aβ_25-35 (10 μΜ) treatment for 24 h induced significant cell death and oxidative stress in PC12 cells, as evidenced by cell viability reduction, LDH release, ROS accumulation and increased production MDA. (1E,4E)-1, 5-bis(4-hydroxy-3-methoxyphenyl) penta-1, 4-dien-3-one (CB) and (1E, 4E)-1-(3, 4-dimethoxyphenyl)-5-(4-hydroxy-3, 5-dime-thoxyphenyl) Penta-1, 4-dien-3-one (FE), two Curcumin (Cur) analogues displayed neuroprotective effects against Aβ_25-35-induced oxidative damage and cellular apoptosis in PC12 cells. Here, we investigated three different treatment ways of CB and FE. It was interesting that post-treatment of CB and FE (restoring way) showed similar effect to the preventive way, while attenuating way did not show any protective effect. We found that low dose CB and FE increased transcriptional factor NF-E2-related factor 2 (Nrf2)/hemo oxygenase 1 (HO-1) protein expression and decreased Kelch-like ECH-associated protein 1 (Keap1) in PC 12 cells. In addition, CB and FE promoted the translation of Nrf2 into nuclear and enhanced the activity of superoxide dismutase (SOD)/catalase, which confirmed cytoprotection against Aβ_25-35-induced oxidative damage. Moreover, CB and FE could increase Bcl-2 expression level, decrease the level of Bax and Cyt-c in Aβ_25-35-treated PC12 cells. Ultimately, the neuroprotective effect of CB and FE provides a pharmacological basis for its clinical use in prevention and treatment of AD.

Synthesis, human topoisomerase IIα inhibitory properties and molecular modeling studies of anti-proliferative curcumin mimics

Piperidinecarboxamides (curcumin mimics) show promising anti-proliferative properties against HCT116 (colon), MCF7 (breast) and A431 (squamous skin) carcinoma cell lines with potency higher than that of 5-fluorouracil.

Synthesis and Cytotoxicity Evaluation of Novel Asymmetrical Mono-Carbonyl Analogs of Curcumin (AMACs) against Vero, HeLa, and MCF7 Cell Lines

A series of novel asymmetrical mono-carbonyl analogs of curcumin (AMACs) were synthesized and evaluated for cytotoxic activity using BSLT and MTT assay against Vero, HeLa, and MCF7 cell lines. The structures of the synthesized compounds were confirmed by FTIR, ¹H-NMR, 13C-NMR, and mass spectral data. The results of the cytotoxicity evaluation showed that the synthesized compounds exhibited moderate to very high toxic activity in BSLT (LC50 value 29.80⁻1704.23 µM); most of the compound exhibited cytotoxic activity against HeLa cell lines, which is comparable to the activity of cisplatin (IC50 value 40.65⁻95.55 µM), and most of the compound tested against MCF7 cell lines exhibited moderate to very high cytotoxic activity (IC50 value 7.86⁻35.88 µM). However, the selectivity index (SI) of the compounds was low (.

Evaluation of the antioxidant properties of curcumin derivatives by genetic function algorithm

The prevalence of degenerative diseases in recent time has triggered extensive research on their control. This condition could be prevented if the body has an efficient antioxidant mechanism to scavenge the free radicals which are their main causes. Curcumin and its derivatives are widely employed as antioxidants. The free radical scavenging activities of curcumin and its derivatives have been explored in this research by the application of quantitative structure activity relationship (QSAR). The entire data set was optimized at the density functional theory (DFT) level using the Becke's three-parameter Lee-Yang-Parr hybrid functional (B3LYP) in combination with the 6-311G^∗ basis set. The training set was subjected to QSAR studies by genetic function algorithm (GFA). Five predictive QSAR models were developed and statistically subjected to both internal and external validations. Also the applicability domain of the developed model was accessed by the leverage approach. Furthermore, the variation inflation factor, (VIF), mean effect (MF) and the degree of contribution (DC) of each descriptor in the resulting model were calculated. The developed models met all the standard requirements for acceptability upon validation with highly impressive results (R=0.965,R2=0.931,Q2(RCV2)=0.887,Rpred2=0.844,cRp2=0.842s=0.226,rmsep=0.362). Based on the results of this research, the most crucial descriptor that influence the free radical scavenge of the curcumins is the nsssN (count of atom-type E-state: >N-) descriptor with DC and MF values of 12.980 and 0.965 respectively.

Curcumin-loaded nanoliposomes linked to homing peptides for integrin targeting and neuropilin-1-mediated internalization

CONTEXT

Curcumin, a naturally occurring polyphenol, has been extensively studied for its broad-spectrum anticancer effects. The potential benefits are, however, limited due to its poor water solubility and rapid degradation which result in low bioavailability on administration.

OBJECTIVES

This study encapsulates curcumin in nanoliposomes including an integrin-homing peptide combined with a C end R neuropilin-1 targeting motif for targeted delivery and receptor-mediated internalization, respectively.

MATERIALS AND METHODS

The linear GHHNGR (Glycine-Histidine-Histidine-Asparagine-Glycine-Arginine) was synthesized through F-moc chemistry on 2-chlorotrityl chloride resin and conjugated to oleic acid. The lipoyl-peptide units were then co-assembled with lecithin and 0-75 mole % Tween-80 into liposomes. Curcumin was passively entrapped using a film hydration technique and its degradation profile was examined within seven consecutive days. The cytotoxic effects of the curcumin-loaded liposomes were studied on MCF-7 and MDA-MB-468, during 24 h exposure in MTT assay.

RESULTS

The maximum curcumin entrapment (15.5% W/W) and minimum degradation (< 23%) were obtained in a pH switch loading method from 5.7 to 8, in nanoliposomes (< 50 nm) containing oleyl-peptide, lecithin and Tween-80 (1:1:0.75 mole ratio). The oleyl-peptide did not prove any haemolytic activity (< 1.5%) up to 10-fold of its experimental concentration. The curcumin-loaded liposomes displayed significant reduction in the viabilities of MCF-7 (IC₅₀ 3.8 μM) and MDA-MB-468 (IC₅₀ 5.4 μM).

DISCUSSION AND CONCLUSION

This study indicated potential advantages of the peptide-conjugated liposomes in drug transport to the cancer cells. This feature might be an outcome of probable interactions between the targeted nanoliposomes with the integrin and neuropilin-1 receptors.

Synthesis and Reactions of Benzannulated Spiroaminals: Tetrahydrospirobiquinolines

An efficient two-step synthesis of symmetrical and unsymmetrical tetrahydrospirobiquinolines from o-azidobenzaldehydes is reported. A novel series of tetrahydrospirobiquinolines was prepared by sequential double-aldol condensation with acetone, cyclopentanone, and cyclohexanone to form the corresponding o,o'-diazido-dibenzylidene-acetone, -cyclopentanone, and -cyclohexanone derivatives, respectively, and hydrogenation-spirocyclization. The spirodiamines were further derivatized by electrophilic aromatic bromination, Suzuki coupling, and N-alkylation, all of which proceeded with preservation of the spirocyclic core.

Asymmetric 1,5-diarylpenta-1,4-dien-3-ones: Antiproliferative activity in prostate epithelial cell models and pharmacokinetic studies

To further engineer dienones with optimal combinations of potency and bioavailability, thirty-four asymmetric 1,5-diarylpenta-1,4-dien-3-ones (25-58) have been designed and synthesized for the evaluation of their in vitro anti-proliferative activity in three human prostate cancer cell lines and one non-neoplastic prostate epithelial cell line. All these asymmetric dienones are sufficiently more potent than curcumin and their corresponding symmetric counterparts. The optimal dienone 58, with IC₅₀ values in the range of 0.03-0.12 μM, is 636-, 219-, and 454-fold more potent than curcumin in three prostate cancer cell models. Dienones 28 and 49 emerged as the most promising asymmetric dienones that warrant further preclinical studies. The two lead compounds demonstrated substantially improved potency in cell models and superior bioavailability in rats, while exhibiting no acute toxicity in the animals at the dose of 10 mg/kg. Dienones 28 and 46 can induce PC-3 cell cycle regulation at the G₀/G₁ phase. However, dienone 28 induces PC-3 cell death in a different way from 46 even though they share the same scaffold, indicating that terminal heteroaromatic rings are critical to the action of mechanism for each specific dienone.

Synthesis and antioxidant activity of curcumin analogs

Numerous biological activities including antioxidant, antitumor, anti-inflammation, and antivirus of the natural product curcumin were reported. However, the clinical application of it was significantly limited by its instability, poor solubility, less body absorbing, and low bioavailability. This review focuses on the structure modification and antioxidant activity evaluation of curcumin. To study the structure-activity relationship (SAR), five series of curcumin analogs were synthesized and their antioxidant activity were evaluated in vitro. The results showed that electron-donating groups, especially the phenolic hydroxyl group are an essential component to improve the antioxidant activity.

Diarylpentadienone derivatives (curcumin analogues): Synthesis and anti-inflammatory activity

A series of new (2E,4E)-1-(substitutedphenyl)-5-(substitutedphenyl)penta-2,4-dien-1-one derivatives were designed and synthesized. Compounds 3i, 3k were determined by X-ray. All of the compounds have been screened for their anti-inflammatory activity characterized by evaluating their inhibition against LPS-induced IL-6 and TNF-α release in cell RAW 264.7 stimulated with LPS. Compound 3i showed the highest anti-inflammatory activity on decreasing IL-6 and TNF-α. The further study showed that title compound 3i inhibited expression of proteins p-p65, iNOS, COX-2 LPS-induced. Immunofluorescence also revealed compound 3i could lightly reduce activation p65 in nuclei. These results indicate that compound 3i anti-inflammatory role may partly due to its inhibitory effect on the NF-κB signaling pathway.

Phosphotyrosine profiling of curcumin-induced signaling

BACKGROUND

Curcumin, derived from the rhizome Curcuma longa, is a natural anti-cancer agent and has been shown to inhibit proliferation and survival of tumor cells. Although the anti-cancer effects of curcumin are well established, detailed understanding of the signaling pathways altered by curcumin is still lacking. In this study, we carried out SILAC-based quantitative proteomic analysis of a HNSCC cell line (CAL 27) to investigate tyrosine signaling in response to curcumin.

RESULTS

Using high resolution Orbitrap Fusion Tribrid Fourier transform mass spectrometer, we identified 627 phosphotyrosine sites mapping to 359 proteins. We observed alterations in the level of phosphorylation of 304 sites corresponding to 197 proteins upon curcumin treatment. We report here for the first time, curcumin-induced alterations in the phosphorylation of several kinases including TNK2, FRK, AXL, MAPK12 and phosphatases such as PTPN6, PTPRK, and INPPL1 among others. Pathway analysis revealed that the proteins differentially phosphorylated in response to curcumin are known to be involved in focal adhesion kinase signaling and actin cytoskeleton reorganization.

CONCLUSIONS

The study indicates that curcumin may regulate cellular processes such as proliferation and migration through perturbation of the focal adhesion kinase pathway. This is the first quantitative phosphoproteomics-based study demonstrating the signaling events that are altered in response to curcumin. Considering the importance of curcumin as an anti-cancer agent, this study will significantly improve the current knowledge of curcumin-mediated signaling in cancer.

Triazole tethered C5-curcuminoid-coumarin based molecular hybrids as novel antitubulin agents: Design, synthesis, biological investigation and docking studies

Keeping in view the confines allied with presently accessible antitumor agents and success of C5-curcuminoid based bifunctional hybrids as novel antitubulin agnets, molecular hybrids of C5-curcuminoid and coumarin tethered by triazole ring have been synthesized and investigated for in-vitro cytotoxicity against THP-1, COLO-205, HCT-116 and PC-3 human tumor cell lines. The results revealed that the compounds A-2 to A-9, B-2, B-3, B-7 showed significant cytotoxic potential against THP-1, COLO-205 and HCT-116 cell lines, while the PC-3 cell line among these was found to be almost resistant. Structure activity relationship revealed that the nature of Ring X and the length of carbon-bridge (n) connecting triazole ring with coumarin moiety considerably influence the activity. Methoxy substituted phenyl ring as Ring X and two carbon-bridges were found to be the ideal structural features. The most potent compounds (A-2, A-3 and A-7) were further tested for tubulin polymerization inhibition. Compound A-2 was found to significantly inhibit the tubulin polymerization (IC50 = 0.82 μM in THP-1 tumor cells). The significant cytotoxicity and tubulin polymerization inhibition by A-2 was further rationalized by docking studies where it was docked at the curcumin binding site of tubulin.

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.

Development of curcumin-cyclodextrin/cellulose nanocrystals complexes: New anticancer drug delivery systems

The synthesis of curcumin-cyclodextrin/cellulose nanocrystals (CNCx) nano complexes was performed. CNCx were functionalized by ionic association with cationic β-cyclodextrin (CD) and CD/CNCx complexes were used to encapsulate curcumin. Preliminary in vitro results showed that the resulting curcumin-CD/CNCx complexes exerted antiproliferative effect on colorectal and prostatic cancer cell lines, with IC50s lower than that of curcumin alone.

Synthesis and Biological Evaluation of Curcumin Derivatives with Water-Soluble Groups as Potential Antitumor Agents: An in Vitro Investigation Using Tumor Cell Lines

Three series of curcumin derivatives including phosphorylated, etherified, and esterified products of curcumin were synthesized, and their anti-tumor activities were assessed against human breast cancer MCF-7, hepatocellular carcinoma Hep-G2, and human cervical carcinoma HeLa cells. Compared with curcumin, compounds 3, 8, and 9 exhibited stronger antitumor cell line growth activities against HeLa cells. Compound 12 also showed higher antitumor cell line growth activities on MCF-7 cells than curcumin. Among them, 4-((1E,6E)-7-(4-Hydroxy-3-methoxyphenyl)-3,5-dioxohepta-1,6-dienyl)-2-methoxyphenyl dihydrogen phosphate(3) showed the strongest activity with an half maximal inhibitory concentration (IC₅₀) of 6.78 µM against HeLa cells compared with curcumin with an IC₅₀ of 17.67 µM. Stabilities of representatives of the three series were tested in rabbit plasma in vitro, and compounds 3 and 4 slowly released curcumin in plasma. The effect of compound 3 on HeLa cell apoptosis was determined by examining morphological changes by DAPI (4′,6-diamidino-2-phenylindole) staining as well as Annexin V-FITC/ Propidium Iodide (PI) double staining and flow cytometry. The results showed that 3 induced cellular apoptosis in a dose-dependent manner. Together our findings show that 3 merits further investigation as a new potential antitumor drug candidate.

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.