Effect of curcumin on normal and tumor cells: Role of glutathione and bcl-2

Co-delivery of curcumin and serratiopeptidase in HeLa and MCF-7 cells through nanoparticles show improved anti-cancer activity

Curcumin was employed to prepare anticancer nanoparticles (size 175 ± 15 nm) using anti-inflammatory enzyme serratiopeptidase by desolvation method. Here serratiopeptidase acted as a carrier as well as bioactive molecule in the nanoformulations. The Cur-SPD NPs (curcumin loaded serratiopeptidase nanoparticles) were characterized using DLS, FESEM and FTIR. The in vitro release behavior depicted biphasic pattern at 37 °C (pH 7.4) and release of 95% of both molecules occurred in 24 h. Serratiopeptidase not only provided stability to curcumin but also increased its effectiveness against cancer cells. These nanoparticles had anti-cancer activity in MCF-7 and HeLa cell lines as shown by cytotoxicity assay, DAPI nuclear staining, ROS production and DNA damage. The immunomodulatory tests showed that Cur-SPD NPs reduce level of IL-6 but increase TNFα level in THP1 cell lines. Structural similarity of serratiopeptidase to matrix metallo proteases (MMPs), particularly MMP8, have been found (based on low RMSD values) to induce TNFα production and play tumour suppressive role in certain cancers. Thus anti-cancer properties of Cur-SPD NPs may be attributed to synergistic effect of curcumin and serratiopeptidase. Thus results in present investigation provide an insight on role of serratiopeptidase in development of co-delivery of multifunctional nanoparticles with anti-cancer properties introduction.

Phyto-polyphenols as potential inhibitors of breast cancer metastasis

Breast cancer is the most common cancer among women as metastasis is currently the main cause of mortality. Breast cancer cells undergoing metastasis acquire resistance to death signals and increase of cellular motility and invasiveness.Plants are rich in polyphenolic compounds, many of them with known medicinal effects. Various phyto-polyphenols have also been demonstrated to suppress cancer growth. Their mechanism of action is usually pleiotropic as they target multiple signaling pathways regulating key cellular processes such as proliferation, apoptosis and differentiation. Importantly, some phyto- polyphenols show low level of toxicity to untransformed cells, but selective suppressing effects on cancer cells proliferation and differentiation.In this review, we summarize the current information about the mechanism of action of some phyto-polyphenols that have demonstrated anti-carcinogenic activities in vitro and in vivo. Gained knowledge of how these natural polyphenolic compounds work can give us a clue for the development of novel anti-metastatic agents.

CD44 targeting biocompatible and biodegradable hyaluronic acid cross-linked zein nanogels for curcumin delivery to cancer cells: In vitro and in vivo evaluation

In this study, we developed novel hyaluronic acid cross-linked zein nanogels (HA-Zein NGs) to deliver the potential anticancer agent curcumin (CRC), a naturally occurring phytochemical drug in cancer cells. In vitro studies showed that they are highly compatible with the tested cell lines. They showed CD44 specific uptake in CT26 cell line more than by the CD44 receptor pre-inhibited CT26 cells. The CRC encapsulated HA-Zein NGs (HA-Zein-CRC NGs) found to exert a specific toxicity against CT26 sparing healthy normal fibroblast cells in vitro. The apoptotic effects were further confirmed with flow cytometry showing that the HA-Zein-CRC NGs exhibited high anticancer activity against the CT26 cells. The in vivo bio-distribution with a CT26 tumor model showed their high tumor accumulation thereby improved antitumor efficacy with a low dosage of CRC, compared to the previous reports. Thus, the preclinical studies clearly showed that these novel HA-Zein NGs would be highly beneficial in encapsulating hydrophobic drugs with improved pharmacokinetics thereby enhancing the therapeutic outcomes.

An LC-MS/MS method for simultaneous determination of curcumin, curcumin glucuronide and curcumin sulfate in a phase II clinical trial

Curcumin, a principal curcuminoid of turmeric, gained a lot of attention recently due to its wide spectrum of pharmacological activities in prevention and treatment of various human conditions. The current clinical study is focused on the determination of efficacy and tolerability of curcumin and vitamin D₃ combination in patients with early-stage chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). To support this work, an LC-MS/MS method has been developed for simultaneous determination of curcumin and its metabolites, curcumin glucuronide (COG) and curcumin sulfate (COS), in human plasma using curcumin-d₆ as an internal standard for curcumin and BPAG-d₆ as an internal standard for COG and COS. In this method, plasma samples were prepared by methanol protein precipitation, and the analytes were separated on a Waters XTerra^® MS C18 column (2.1 mm × 50 mm, 3.5 μm) using gradient elution with methanol and 10.0 mM ammonium formate (pH 3.0) at a flow rate of 0.250 mL min^-1. Quantitation of curcumin, COG, and COS was carried out by tandem mass spectrometry using negative electrospray ionization in multiple-reaction-monitoring (MRM) mode. The linear calibration range for the method was 2.50-500 ng mL^-1 for curcumin, COG, and COS. The method has been validated in accordance with the US-FDA guidelines for bioanalytical method validation. The developed method has been used for the measurement of curcumin, COG and COS concentrations in human plasma samples from a phase II clinical trial.

Effective delivery of hydrophobic drugs to breast and liver cancer cells using a hybrid inorganic nanocarrier: A detailed investigation using cytotoxicity assays, fluorescence imaging and flow cytometry

This study was focused on developing a drug carrier system composed of a polymer containing hydroxyapatite (HAp) shell and a magnetic core of iron oxide nanoparticles. Doxorubicin and/or curcumin were loaded into the carrier via a simple diffusion deposition approach, with encapsulation efficiencies (EE) for curcumin and doxorubicin of 93.03 ± 0.3% and 97.37 ± 0.12% respectively. The co-loading of curcumin and doxorubicin led to a total EE of 76.02 ± 0.48%. Release studies were carried out at pH 7.4 and 5.3, and revealed a greater extent of release at pH 5.3, showing the formulations to have potential applications in tumor microenvironments. Cytotoxicity assays, fluorescence imaging and flow cytometry demonstrated that the formulations could effectively inhibit the growth of MCF-7 (breast) and HEpG2 (liver) cancer cells, being more potent than the free drug molecules both in terms of dose and duration of action. Additionally, hemolysis tests and cytotoxicity evaluations determined the drug-loaded carriers to be non-toxic towards non-cancerous cells. These formulations thus have great potential in the development of new cancer therapeutics.

Gallic acid and curcumin induce cytotoxicity and apoptosis in human breast cancer cell MDA-MB-231

Introduction: Gallic acid (GA) and curcumin (Cur) are natural phenolic compounds that their anti-tumor effects on many types of cancers have been proved. In the current study, the effect of the combination of these agents on MDA-MB-231 breast cancer cells was investigated.

Methods: Inhibition of cell proliferation (MTT assay), light microscopy, fluorescence microscopy, cell cycle analysis, nitrite detection, ROS levels, measurement of the mitochondrial membrane potential, GSH level, Annexin V assay, RT-PCR and Western blotting methods were applied.

Results: The results revealed the combination of GA and Cur strongly decreased MDA-MB-231 cell growth. Moreover, this combination increased ROS level and cytotoxic activity along with the glutathione depletion in MDA-MB-231 cells. Flow cytometry analysis showed the combination of GA and Cur increased sub-G1 cell population. Furthermore, fluorescent staining and Annexin V/PI assay showed that apoptotic cells were significantly increased in the presence of GA and Cur. At last, protein expression evaluation showed that the combination of GA and Cur significantly decreased Bcl-2 level while increased Bax, cleaved-caspase3 and PARP levels in MDA-MB-231 cells.

Conclusion: These results suggest that GA in combination with Cur could be a possible candidate for chemoprevention agent of triple negative breast cancer.

Production of Curcumin-Loaded Silk Fibroin Nanoparticles for Cancer Therapy

Curcumin, extracted from the rhizome of Curcuma longa, has been widely used in medicine for centuries due to its anti-inflammatory, anti-cancer, anti-oxidant and anti-microbial effects. However, its bioavailability during treatments is poor because of its low solubility in water, slow dissolution rate and rapid intestinal metabolism. For these reasons, improving the therapeutic efficiency of curcumin using nanocarriers (e.g., biopolymer nanoparticles) has been a research focus, to foster delivery of the curcumin inside cells due to their small size and large surface area. Silk fibroin from the Bombyx mori silkworm is a biopolymer characterized by its biocompatibility, biodegradability, amphiphilic chemistry, and excellent mechanical properties in various material formats. These features make silk fibroin nanoparticles useful vehicles for delivering therapeutic drugs, such as curcumin. Curcumin-loaded silk fibroin nanoparticles were synthesized using two procedures (physical adsorption and coprecipitation) more scalable than methods previously described using ionic liquids. The results showed that nanoparticle formulations were 155 to 170 nm in diameter with a zeta potential of approximately -45 mV. The curcumin-loaded silk fibroin nanoparticles obtained by both processing methods were cytotoxic to carcinogenic cells, while not decreasing viability of healthy cells. In the case of tumor cells, curcumin-loaded silk fibroin nanoparticles presented higher efficacy in cytotoxicity against neuroblastoma cells than hepatocarcinoma cells. In conclusion, curcumin-loaded silk fibroin nanoparticles constitute a biodegradable and biocompatible delivery system with the potential to treat tumors by local, long-term sustained drug delivery.

L-Ferritin targets breast cancer stem cells and delivers therapeutic and imaging agents

A growing body of evidence suggests that cancer stem cells (CSC) have the unique biological properties necessary for tumor maintenance and spreading, and function as a reservoir for the relapse and metastatic evolution of the disease by virtue of their resistance to radio- and chemo-therapies. Thus, the efficacy of a therapeutic approach relies on its ability to effectively target and deplete CSC. In this study, we show that CSC-enriched tumorspheres from breast cancer cell lines display an increased L-Ferritin uptake capability compared to their monolayer counterparts as a consequence of the upregulation of the L-Ferritin receptor SCARA5. L-Ferritin internalization was exploited for the simultaneous delivery of Curcumin, a natural therapeutic molecule endowed with antineoplastic action, and the MRI contrast agent Gd-HPDO3A, both entrapped in the L-Ferritin cavity. This theranostic system was able to impair viability and self-renewal of tumorspheres in vitro and to induce the regression of established tumors in mice. In conclusion, here we show that Curcumin-loaded L-Ferritin has a strong therapeutic potential due to the specific targeting of CSC and the improved Curcumin bioavailability, opening up the possibility of its use in a clinical setting.

Cytoplasmic vacuolization in cell death and survival

Cytoplasmic vacuolization (also called cytoplasmic vacuolation) is a well-known morphological phenomenon observed in mammalian cells after exposure to bacterial or viral pathogens as well as to various natural and artificial low-molecular-weight compounds. Vacuolization often accompanies cell death; however, its role in cell death processes remains unclear. This can be attributed to studying vacuolization at the level of morphology for many years. At the same time, new data on the molecular mechanisms of the vacuole formation and structure have become available. In addition, numerous examples of the association between vacuolization and previously unknown cell death types have been reported. Here, we review these data to make a deeper insight into the role of cytoplasmic vacuolization in cell death and survival.

Effects of six common dietary nutrients on murine intestinal organoid growth

The intestinal epithelium of the gastrointestinal (GI) tract constantly renews itself to absorb nutrients and provide protection for the body from the outside world. Since the intestinal epithelium is constantly exposed to various chemicals and dietary components, it is critical to determine which constituents promote or inhibit intestinal epithelium health and growth rate. Intestinal organoids, three-dimensional miniature models of the intestines, represent an ex vivo tool to investigate intestinal physiology and growth patterns. In this study, we measured the growth rates of murine intestinal organoids exposed to various concentrations of different dietary constituents. Results indicate that caffeic acid inhibited organoid growth in a concentration-dependent manner, curcumin exhibited variable effectiveness, and vitamin C had no effect on organoid growth.

Regulation of Polyamine Metabolism by Curcumin for Cancer Prevention and Therapy

Curcumin (diferuloylmethane), the natural polyphenol responsible for the characteristic yellow pigment of the spice turmeric (Curcuma longa), is traditionally known for its antioxidant, anti-inflammatory, and anticarcinogenic properties. Capable of affecting the initiation, promotion, and progression of carcinogenesis through multiple mechanisms, curcumin has potential utility for both chemoprevention and chemotherapy. In human cancer cell lines, curcumin has been shown to decrease ornithine decarboxylase (ODC) activity, a rate-limiting enzyme in polyamine biosynthesis that is frequently upregulated in cancer and other rapidly proliferating tissues. Numerous studies have demonstrated that pretreatment with curcumin can abrogate carcinogen-induced ODC activity and tumor development in rodent tumorigenesis models targeting various organs. This review summarizes the results of curcumin exposure with regard to the modulation of polyamine metabolism and discusses the potential utility of this natural compound in conjunction with the exploitation of dysregulated polyamine metabolism in chemopreventive and chemotherapeutic settings.

Hydrophobic Drug-Loaded PEGylated Magnetic Liposomes for Drug-Controlled Release

Less targeted and limited solubility of hydrophobic-based drug are one of the serious obstacles in drug delivery system. Thus, new strategies to enhance the solubility of hydrophobic drug and controlled release behaviors would be developed. Herein, curcumin, a model of hydrophobic drug, has been loaded into PEGylated magnetic liposomes as a drug carrier platform for drug controlled release system. Inductive magnetic heating (hyperthermia)-stimulated drug release, in vitro cellular cytotoxicity assay of curcumin-loaded PEGylated magnetic liposomes and cellular internalization-induced by magnetic guidance would be investigated. The resultant of drug carriers could disperse homogeneously in aqueous solution, showing a superparamagnetic characteristic and could inductive magnetic heating with external high-frequency magnetic field (HFMF). In vitro curcumin release studies confirmed that the drug carriers exhibited no significant release at 37 °C, whereas exhibited rapid releasing at 45 °C. However, it would display enormous (three times higher) curcumin releasing under the HFMF exposure, compared with that without HFMF exposure at 45 °C. In vitro cytotoxicity test shows that curcumin-loaded PEGylated magnetic liposomes could efficiently kill MCF-7 cells in parallel with increasing curcumin concentration. Fluorescence microscopy observed that these drug carriers could internalize efficiently into the cellular compartment of MCF-7 cells. Thus, it would be anticipated that the novel hydrophobic drug-loaded PEGylated magnetic liposomes in combination with inductive magnetic heating are promising to apply in the combination of chemotherapy and thermotherapy for cancer therapy.

Solid Lipid Curcumin Particles Induce More DNA Fragmentation and Cell Death in Cultured Human Glioblastoma Cells than Does Natural Curcumin

Despite recent advancements in cancer therapies, glioblastoma multiforme (GBM) remains largely incurable. Curcumin (Cur), a natural polyphenol, has potent anticancer effects against several malignancies, including metastatic brain tumors. However, its limited bioavailability reduces its efficiency for treating GBM. Recently, we have shown that solid lipid Cur particles (SLCPs) have greater bioavailability and brain tissue penetration. The present study compares the efficiency of cell death by Cur and/or SLCPs in cultured GBM cells derived from human (U-87MG) and mouse (GL261) tissues. Several cell viability and cell death assays and marker proteins (MTT assay, annexin-V staining, TUNEL staining, comet assay, DNA gel electrophoresis, and Western blot) were investigated following the treatment of Cur and/or SLCP (25 μM) for 24–72 h. Relative to Cur, the use of SLCP increased cell death and DNA fragmentation, produced longer DNA tails, and induced more fragmented nuclear lobes. In addition, cultured GBM cells had increased levels of caspase-3, Bax, and p53, with decreases in Bcl₂, c-Myc, and both total Akt, as well as phosphorylated Akt, when SLCP, rather Cur, was used. Our in vitro work suggests that the use of SLCP may be a promising strategy for reversing or preventing GBM growth, as compared to using Cur.

Cucurmin, anticancer, & antitumor perspectives: A comprehensive review

Cucurmin, a naturally yellow component isolated from turmeric, ability to prevent various life-style related disorders. The current review article mainly emphasizes on different anticancer perspectives of cucurmin, i.e., colon, cervical, uterine, ovarian, prostate head and neck, breast, pulmonary, stomach and gastric, pancreatic, bladder oral, oesophageal, and bone cancer. It holds a mixture of strong bioactive molecule known as cucurminoids that has ability to reduce cancer/tumor at initial, promotion and progression stages of tumor development. In particular, these compounds block several enzymes required for the growth of tumors and may therefore involve in tumor treatments. Moreover, it modulates an array of cellular progressions, i.e., nitric oxide synthetase activity, protein kinase C activity, epidermal growth factor (EGF) receptor intrinsic kinase activity, nuclear factor kappa (NF-kB) activity, inhibiting lipid peroxidation and production of reactive oxygen species. However, current manuscript summarizes most of the recent investigations of cucurmin but still further research should be conducted to explore the role of curcumin to mitigate various cancers.

Enrichment and Cytotoxic Activity of Curcuminoids from Turmeric Using Macroporous Resins

Curcuminoids are functional secondary metabolites abundant in turmeric. In the present study, a simple and efficient method for enrichment of curcuminoids from turmeric was developed using macroporous resin. Eight different types of macroporous resins were examined by static adsorption/desorption properties and the type of XDA-7 was selected as the optimum one. Under the optimized conditions, the final contents of refined extract excluded 84.2% of impurities, by comparison with crude extract in a scale-up experiment. Meanwhile, 8 representative curcuminoids including 4 dihydro- and tetrahydro-curcuminoids were enriched, isolated, and identified by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR) data. In addition, the individual curcuminoids were prepared to evaluate their cytotoxic activity toward HeLa tumor cell lines. All compounds, especially the trace amount of curcuminoids, demonstrated notable cytotoxic activity. The results supported that those trace amount of curcuminoids can be good candidates for drug development as anticancer agents. The purification process was simple and efficient, which could afford a potential method to enrich and concentrate not only the major curcuminoids, but also the trace amount of ones from turmeric raw materials for industrial applications.

Multifunctional Curcumin Mediate Multitherapeutic Effects

Inflammation can promote the development of arthritis, obesity, cardiovascular, type II diabetes, pancreatitis, metabolic and neurodegenerative diseases, and certain types of cancer. Compounds isolated from plants have been practiced since ancient times for curing various ailments including inflammatory disorders and to support normal physiological functions. Curcumin (diferuloylmethane) is a yellow coloring agent, extracted from turmeric that has been used for the prevention and treatment of various inflammatory diseases. Numerous studies have shown that curcumin modulate multiple molecular targets and can be translated to the clinics for multiple therapeutic processes. There is compelling evidence that curcumin can block cell proliferation, invasion, and angiogenesis as well as reduced the prolonged survival of cancer cells. Curcumin mediates anti-inflammatory effect through downregulation of inflammatory cytokines, transcription factors, protein kinases, and enzymes that promote inflammation and development of chronic diseases. In addition, curcumin induces apoptosis through mitochondrial and receptor-mediated pathways by activating caspase cascades. Curcumin is a safe and nontoxic drug that has been reported to be well tolerated. Available clinical trials support the potential role of curcumin for treatment of various inflammatory disorders. However, curcumin's efficacy is hindered by poor absorption and low bioavailability, which limit its translation into clinics. This review outlines the potential pharmacological and clinical role of curcumin, which provide a gateway for the beneficial role of plant isolated compounds in treatment of various inflammatory diseases and cancer.

Curcumin: An age-old anti-inflammatory and anti-neoplastic agent

Curcumin is a natural anti-inflammatory agent that has been used for treating medical conditions for many years. Several experimental and pharmacologic trials have demonstrated its efficacy in the role as an anti-inflammatory agent. Curcumin has been shown to be effective in treating chronic conditions like rheumatoid arthritis, inflammatory bowel disease, Alzheimer's and common malignancies like colon, stomach, lung, breast, and skin cancers. As treatments in medicine become more and more complex, the answer may be something simpler. This is a review article written with the objective to systematically analyze the wealth of information regarding the medical use of curcumin, the "curry spice", and to understand the existent gaps which have prevented its widespread application in the medical community.

Biological and pharmacological evaluation of dimethoxycurcumin: A metabolically stable curcumin analogue with a promising therapeutic potential

Dimethoxycurcumin (DiMC) is a synthetic analog of curcumin with superior inter-related pro-oxidant and anti-cancer activity, and metabolic stability. Numerous studies have shown that DiMC reserves the biologically beneficial features, including anti-inflammatory, anti-carcinogenic, and cytoprotective properties, almost to the same extent as curcumin exhibits. DiMC lacks the phenolic-OH groups as opposed to curcumin, dimethoxycurcumin, and bis-demethoxycurcumin that all vary in the number of methoxy groups per molecule, and has drawn the attentions of researchers who attempted to discover the structure-activity relationship (SAR) of curcumin. In this regard, tetrahydrocurcumin (THC), the reduced and biologically inert metabolite of curcumin, denotes the significance of the conjugated α,β diketone moiety for the curcumin activity. DiMC exerts unique molecular activities compared to curcumin, including induction of androgen receptor (AR) degradation and suppression of the transcription factor activator protein-1 (AP-1). The enhanced AR degradation on DiMC treatment suggests it as a novel anticancer agent against resistant tumors with androgenic etiology. Further, DiMC might be a potential treatment for acne vulgaris. DiMC induces epigenetic alteration more effectively than curcumin, although both showed no direct DNA hypomethylating activity. Given the metabolic stability, nanoparticulation of DiMC is more promising for in vivo effectiveness. However, studies in this regard are still in its infancy. In the current review, we portray the various molecular and biological functions of DiMC reported so far. Whenever possible, the efficiency is compared with curcumin and the reasons for DiMC being more metabolically stable are elaborated. We also provide future perspective investigations with respect to varying DiMC-nanoparticles.

Theranostic Nanoparticles Loaded with Imaging Probes and Rubrocurcumin for Combined Cancer Therapy by Folate Receptor Targeting

The combination of different therapeutic modalities is a promising option to combat the recurrence of tumors. In this study, polylactic and polyglycolic acid nanoparticles were used for the simultaneous delivery of a boron-curcumin complex (RbCur) and an amphiphilic gadolinium complex into tumor cells with the aim of performing boron and gadolinium neutron capture therapy (NCT) in conjunction with the additional antiproliferative effects of curcumin. Furthermore, the use of Gd complexes allows magnetic resonance imaging (MRI) assessment of the amount of B and Gd internalized by tumor cells. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were targeted to ovarian cancer (IGROV-1) cells through folate receptors, by including in the formulation a PEGylated phospholipid functionalized with the folate moiety. NCT was performed on IGROV-1 cells internalizing 6.4 and 78.6 μg g^-1 of ¹⁰ B and ¹⁵⁷ Gd, respectively. The synergic action of neutron treatment and curcumin cytotoxicity was shown to result in a significant therapeutic improvement.

Anticancer Activity of Curcumin and Its Analogues: Preclinical and Clinical Studies

Curcumin has been shown to have a wide variety of therapeutic effects, ranging from anti-inflammatory, chemopreventive, anti-proliferative, and anti-metastatic. This review provides an overview of the recent research conducted to overcome the problems with the bioavailability of curcumin, and of the preclinical and clinical studies that have reported success in combinatorial strategies coupling curcumin with other treatments. Research on the signaling pathways that curcumin treatment targets shows that it potently acts on major intracellular components involved in key processes such as genomic modulations, cell invasion and cell death pathways. Curcumin is a promising molecule for the prevention and treatment of cancer.

Localization and dynamics of the anticarcinogenic curcumin with GM1 and other miceller assemblies

Structural transitions involving shape changes play an important role in cellular physiology and enhance the bioavailability of the natural food like curcumin in surfactant aggregates. In this work, we have studied the localization, dynamics and stability of curcumin in various miceller assemblies using a combination of absorbance and fluorescence spectroscopic approaches. The measurements of absorption and fluorescence spectra of curcumin revealed that the nature of interactions of ionic and nonionic surfactants and the glycosphingolipid, GM₁ with curcumin is significantly different with surfactant concentrations. At low concentrations of SDS and the GM₁ the head group of SDS and GM₁ binds to the central β-diketone group of curcumin to form SDS-curcumin or GM₁-curcumin complexes. At high concentrations, both formed micelles with curcumin completely solubilized inside. Cucurmin is solubilized in the stern layer of SDS micelles. Compared to spherical micelles, rod shaped micelles allow more curcumin to bind through hydrophobic interactions indicated by higher absorption and fluorescence, enhanced partition coefficient and stability. Whereas curcumin associates with GM₁ micelles with lower partition coefficient, solubility and remain closer to aqueous phase decreasing its bioavailability and stability. While cucurmin is solubilized in the palisade layer of deoxycholate and octyl glucopyranoside micelles through the alkyl chains providing more hydrophobic microenvironment to curcumin with enhanced stability and bioavailability. Graphical abstract Schematic diagram of the two different types of detergent micelles and larger GM1 micelles.

A Subpopulation of the K562 Cells Are Killed by Curcumin Treatment after G2/M Arrest and Mitotic Catastrophe

Curcumin is extensively investigated as a good chemo-preventive agent in the development of many cancers and particularly in leukemia, including treatment of chronic myelogenous leukemia and it has been proposed as an adjuvant for leukemia therapies. Human chronic myeloid leukemia cells (K562), were treated with 20 μM of curcumin, and we found that a subpopulation of these cells were arrested and accumulate in the G2/M phase of the cell cycle. Characterization of this cell subpopulation showed that the arrested cells presented nuclear morphology changes resembling those described for mitotic catastrophe. Mitotic cells displayed abnormal chromatin organization, collapse of the mitotic spindle and abnormal chromosome segregation. Then, these cells died in an apoptosis dependent manner and showed diminution in the protein levels of BCL-2 and XIAP. Moreover, our results shown that a transient activation of the nuclear factor κB (NFκB) occurred early in these cells, but decreased after 6 h of the treatment, explaining in part the diminution of the anti-apoptotic proteins. Additionally, P73 was translocated to the cell nuclei, because the expression of the C/EBPα, a cognate repressor of the P73 gene, was decreased, suggesting that apoptosis is trigger by elevation of P73 protein levels acting in concert with the diminution of the two anti-apoptotic molecules. In summary, curcumin treatment might produce a P73-dependent apoptotic cell death in chronic myelogenous leukemia cells (K562), which was triggered by mitotic catastrophe, due to sustained BAX and survivin expression and impairment of the anti-apoptotic proteins BCL-2 and XIAP.

c-Jun N-terminal kinase-dependent apoptotic photocytotoxicity of solvent exchange-prepared curcumin nanoparticles

Indian spice curcumin is known for its anticancer properties, but the anticancer mechanisms of nanoparticulate curcumin have not been completely elucidated. We here investigated the in vitro anticancer effect of blue light (470 nm, 1 W)-irradiated curcumin nanoparticles prepared by tetrahydrofuran/water solvent exchange, using U251 glioma, B16 melanoma, and H460 lung cancer cells as targets. The size of curcumin nanocrystals was approximately 250 nm, while photoexcitation induced their oxidation and partial agglomeration. Although cell membrane in the absence of light was almost impermeable to curcumin nanoparticles, photoexcitation stimulated their internalization. While irradiation with blue light (1-8 min) or nanocurcumin (1.25-10 μg/ml) alone was only marginally toxic to tumor cells, photoexcited nanocurcumin displayed a significant cytotoxicity depending both on the irradiation time and nanocurcumin concentration. Photoexcited nanocurcumin induced phosphorylation of c-Jun N-terminal kinase (JNK), mitochondrial depolarization, caspase-3 activation, and cleavage of poly (ADP-ribose) polymerase, indicating apoptotic cell death. Accordingly, pharmacologial inhibition of JNK and caspase activity rescued cancer cells from photoexcited nanocurcumin. On the other hand, antioxidant treatment did not reduce photocytotoxicity of nanocurcumin, arguing against the involvement of oxidative stress. By demonstrating the ability of photoexcited nanocurcumin to induce oxidative-stress independent, JNK- and caspase-dependent apoptosis, our results support its further investigation in cancer therapy.

A Silver(I)-Estrogen Nanocluster: GSH Sensitivity and Targeting Suppression on HepG2 Cell

A structure-determined silver nanocluster of [Ag₁₀ (Eth)₄ (CF₃ COO)₆ (CH₃ OH)₃ ]·3C-H₃ OH (Eth = ethisterone) (1), is firstly demonstrated by self-assembly of silver salt and ethisterone. Due to the thiophilicity of silver(I) ions, complex 1 shows reactivity with glutathione (GSH) molecules in solution and induces the fluorescence quenching behavior. Thus, complex 1 can be used as a fluorescent sensor for GSH. In consideration of the higher level of GSH in cancerous cells, complex 1 presents significant tumor suppression reactivity toward the human hepatocellular carcinoma (HepG2) cells with IC₅₀ value of 165 × 10^-9 m. Especially, complex 1 displays 3.4-fold higher in vitro cytotoxicity to HepG2 cells than that of the normal CCC-HEL-1 cells, which makes complex 1 a potential targeting suppression agent for cancerous cells. The molecular design of complex 1 not only generates a new medicine-silver(I) cluster family, but also opens a new avenue to the targeting anticancer organosilver(I) materials.

Diamond Nanoparticles Modify Curcumin Activity: In Vitro Studies on Cancer and Normal Cells and In Ovo Studies on Chicken Embryo Model

Curcumin has been studied broadly for its wide range of biological activities, including anticancer properties. The major problem with curcumin is its poor bioavailability, which can be improved by the addition of carriers, such as diamond nanoparticles (DN). They are carbon allotropes, and are therefore biocompatible and easily taken up by cells. DN are non-toxic and have antiangiogenic properties with potential applications in cancer therapy. Their large surface makes them promising compounds in a drug delivery system for bioactive agents, as DN create bio-complexes in a fast and simple process of self-organisation. We investigated the cytotoxicity of such bio-complexes against liver cancer cells and normal fibroblasts, revealing that conjugation of curcumin with DN significantly improves its activity. The experiment performed in a chicken embryo model demonstrated that neither curcumin nor DN nor bio-complexes affect embryo development, even though DN can form deposits in tissues. Preliminary results confirmed the applicability of DN as an efficient carrier of curcumin, which improves its performance against cancer cells in vitro, yet is not toxic to an organism, which makes the bio-complex a promising anticancer agent.

Designing piperlongumine-directed anticancer agents by an electrophilicity-based prooxidant strategy: A mechanistic investigation

Piperlongumine (PL), a natural electrophilic alkaloid bearing two α, β-unsaturated imides, is a promising anticancer molecule by targeting the stress response to reactive oxygen species (ROS). Considering that ROS generation depends on electrophilicity of PL, PL-CL was designed as its analog by introducing the α-substituent chlorine on the lactam ring to increase moderately its electrophilicity. In comparison with the parent molecule, this molecule was identified as a stronger ROS (O2(∙-) and H2O2) inducer and cytotoxic agent, and manifested more than 15-fold selectivity toward A549 cells over normal WI-38 cells. Mechanistic study uncovers for the first time that the selenoprotein thioredoxin reductase (TrxR) is one of the targets by which PL-CL promotes the ROS generation. Stronger intracellular TrxR inhibition and higher accumulation of ROS (O2(∙-) and H2O2) are responsible for more effective S-phase arrest and mitochondria-mediated apoptotic induction of A549 cells by PL-CL than PLvia p53-p21-cyclinA/CDK2 and ASK1-JNK/p38 signaling cascade pathways, respectively. This work provides an example of successfully designing PL-directed anticancer agent by an electrophilicity-based prooxidant (ROS-generating agent) strategy and gives added confidence for extending this strategy to other natural products.

Curcumin and Osteosarcoma: Can Invertible Polymeric Micelles Help?

Systematic review of experimental and clinical data on the use of curcumin in the treatment of osteosarcoma is presented. The current status of curcumin's therapeutic potential against bone cancer is analyzed in regard to using polymeric micelles (including recently developed invertible, responsive, micelles) as a platform for curcumin delivery to treat osteosarcoma. The potential of micellar assemblies from responsive macromolecules in a controlled delivery of curcumin to osteosarcoma cells, and the release using a new inversion mechanism is revealed.

2,2'-Fluorine mono-carbonyl curcumin induce reactive oxygen species-Mediated apoptosis in Human lung cancer NCI-H460 cells

In this paper, we synthesized three fluorine-substituted mono-carbonyl curcumin analogs and evaluated their cytotoxicity against several cancer cells by the MTT assay. The results exhibited that all the three compounds were more active than the leading curcumin. Especially, 2,2'-F mono-carbonyl curcumin, 1a, surfaced as an important lead compound displaying almost 4-fold cytotoxicity relative to curcumin. More importantly, 1a was more stable in (RPMI)-1640 medium and more massive uptake than curcumin, which may be relationship to their cytotoxicity, apoptotic acitivity and reactive oxygen species generation. And then, the generation of reactive oxygen species 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 2,2'-F mono-carbonyl curcumin (1a) may cause cancer cells apoptosis through reactive oxygen species-Mediated pathway, but also gives us an important information for design of mono-carbonyl curcumin analog.

pH-Assisted surface functionalization of selenium nanoparticles with curcumin to achieve enhanced cancer chemopreventive activity

A pH-assisted strategy is proposed for synthesizing curcumin-functionalized selenium nanoparticles (SeNPs@Cur), which well combine the advantages of SeNPs with those of Cur in cancer chemoprevention and overcome their limitations in application.

Targeting pioneering factor and hormone receptor cooperative pathways to suppress tumor progression

Nuclear receptors and pioneer factors drive the development and progression of prostate cancer. In this disease, aggressive disease phenotypes and hormone therapy failures result from resurgent activity of androgen receptor (AR) and the upregulation of coactivator protein p300 and pioneer factors (e.g., GATA2 and FOXA1). Thus, a major emphasis in the field is to identify mechanisms by which castrate-resistant AR activity and pioneer factor function can be combinatorially suppressed. Here we show that the turmeric spice isoflavone curcumin suppresses p300 and CBP occupancy at sites of AR function. Curcumin reduced the association of histone acetylation and pioneer factors, thereby suppressing AR residence and downstream target gene expression. Histone deacetylase inhibitors reversed the effects of curcumin on AR activity, further underscoring the impact of curcumin on altering the chromatin landscape. These functions precluded pioneer factor occupancy, leading ultimately to a suppression of ligand-dependent and ligand-independent AR residence on chromatin. Moreover, these functions were conserved even in cells with heightened pioneer factor activity, thus identifying a potential strategy to manage this subclass of tumors. Biological relevance was further identified using in vivo xenograft models mimicking disease progression. Curcumin cooperated in vivo with androgen deprivation as indicated by a reduction in tumor growth and delay to the onset of castrate-resistant disease. Together, our results show the combinatorial impact of targeting AR and histone modification in prostate cancer, thus setting the stage for further development of curcumin as a novel agent to target AR signaling.

Curcumin induced nanoscale CD44 molecular redistribution and antigen-antibody interaction on HepG2 cell surface

The cell surface glycoprotein CD44 was implicated in the progression, metastasis and apoptosis of certain human tumors. In this study, we used atomic force microscope (AFM) to monitor the effect of curcumin on human hepatocellular carcinoma (HepG2) cell surface nanoscale structure. High-resolution imaging revealed that cell morphology and ultrastructure changed a lot after being treated with curcumin. The membrane average roughness increased (10.88 ± 4.62 nm to 129.70 ± 43.72 nm) and the expression of CD44 decreased (99.79 ± 0.16% to 75.14 ± 8.37%). Laser scanning confocal microscope (LSCM) imaging showed that CD44 molecules were located on the cell membrane. The florescence intensity in control group was weaker than that in curcumin treated cells. Most of the binding forces between CD44 antibodies and untreated HepG2 cell membrane were around 120-220 pN. After being incubated with curcumin, the major forces focused on 70-150 pN (10 μM curcumin-treated) and 50-120 pN (20 μM curcumin-treated). These results suggested that, as result of nanoscale molecular redistribution, changes of the cell surface were in response to external treatment of curcumin. The combination of AFM and LSCM could be a powerful method to detect the distribution of cell surface molecules and interactions between molecules and their ligands.

Evaluation of antiviral activities of curcumin derivatives against HSV-1 in Vero cell line

Antiviral drug resistance is one of the most common problems in medicine, and, therefore, finding new antiviral agents, especially from natural resources, seems to be necessary. This study was designed to assay the antiviral activity of curcumin and its new derivatives like gallium-curcumin and Cu-curcumin on replication of HSV-1 in cell culture. The research was performed as an in vitro study in which the antiviral activity of different concentrations of three substances including curcumin, Gallium-curcumin and Cu-curcumin were tested on HSV-1. The cytotoxicity of the tested compounds was also evaluated on the Vero cell line. The CC50 values for curcumin, gallium-curcumin and Cu-curcumin were 484.2 microg/mL, 255.8 microg/mL and 326.6 microg/mL, respectively, and the respective IC50 values 33.0 microg/mL, 13.9 microg/mL and 23.1 microg/mL. The calculated SI values were 14.6, 18.4 and 14.1, respectively. The results showed that curcumin and its new derivatives have remarkable antiviral effects on HSV-1 in cell culture.

Curcumin induced HepG2 cell apoptosis-associated mitochondrial membrane potential and intracellular free Ca(2+) concentration

Curcumin is a phytochemicals which is able to inhibit carcinogenesis in a variety of cell lines. However little is known about its effect on the cell-surface and the interaction between cell-surface and the reacting drug. In this study, we found that curcumin could inhibit the growth of human hepatocellular carcinoma cell line (HepG2), change the cell-surface morphology and trigger the pro-apoptotic factor to promote cell apoptosis. Cell counting kit results indicated that the cell viability had a dose-dependent relationship with the curcumin concentration in 24h. The 50% inhibiting concentration (IC50) was 17.5±3.2μM. It was clear that curcumin could lead to apoptosis, and the apoptosis increased as the reacting concentration goes up. Moreover, curcumin could also affect the disruption of mitochondrial membrane potential and the disturbance of intracellular free Ca(2+) concentration. All these alterations changed the cell morphology and cell-surface ultrastructure with atomic force microscopy (AFM) detecting at nanoscale level. AFM results indicated that cells in control group clearly revealed a typical long spindle-shaped morphology. Cell tails was wide and unrolled. The ultrastructure showed that cell membrane was made up of many nanoparticles. After being treated with curcumin, cell tail was narrowed. The size of membrane nanoparticles became small. These results can improve our understanding of curcumin which can be potentially developed as a new agent for treatment of hepatocellular carcinoma since it has been reported to have a low cytotoxic effect on healthy cell. AFM can be used as a powerful tool for detecting ultrastructures.