curcumin and dimethoxycurcumin

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.

Topics: Animals; Anti-Inflammatory Agents; Antineoplastic Agents, Phytogenic; Antioxidants; Apoptosis; Curcumin; Drug Compounding; Drug Stability; Humans; Molecular Structure; Nanoparticles; Oxidative Stress; Proteolysis; Receptors, Androgen; Signal Transduction; Structure-Activity Relationship; Transcription Factor AP-1

Dimethoxycurcumin (Dimc), a metabolically stable analogue of curcumin, is under investigation as an anti-tumour agent. Recently a number of studies have been performed on Dimc in this laboratory and also by others. In the present article, all these results have been summarized and wherever possible compared with those of curcumin. Rate constant for reactions of Dimc with superoxide radicals was comparable with that of curcumin, while its reaction with peroxyl radicals was much slower. These results were further supported by the observations on the scavenging of basal ROS levels in lymphocytes and evaluation of antioxidant activities. In line with the earlier reports on curcumin, Dimc was a pro-oxidant and generated ROS in tumour cells. Both curcumin and Dimc were non-toxic to lymphocytes, while exhibiting comparable cytotoxicity to tumour cells. Additionally, these compounds showed higher uptake in tumour cells than in normal lymphocytes. Fluorescence studies on both the compounds revealed their binding to genomic DNA, similar sub-cellular distribution and nuclear localization. All these studies suggested that methylation of the phenolic-OH group in curcumin, although decreasing the antioxidant activity marginally, showed comparable pro-oxidant activity, making it a promising anti-tumour agent.

Topics: Animals; Antineoplastic Agents; Antioxidants; Curcumin; Drug Evaluation, Preclinical; Humans; Lymphocytes; Oxidation-Reduction; Spleen; Structure-Activity Relationship

Combinational therapy is a new trend in medical sciences to achieve a maximum therapeutic response of the drugs with a comparatively low incidence of severe adverse effects. To overcome the challenges of conventional formulations for cancer chemotherapy, a polymer-based complex nanomicellar system, namely CPM-DD, was developed co-delivering the anti-cancer agent doxorubicin (DOX) and potent antioxidant dimethoxycurcumin (DiMC). The optimal mass ratio of DOX/DiMC in CPM-DD was determined as 1:6 due to the synergistic antiproliferative effect from

Topics: Animals; Breast Neoplasms; Curcumin; Doxorubicin; Drug Carriers; Female; Humans; Mice; Mice, Nude; Micelles; Nanoparticles; Polymers; Tissue Distribution

Curcumin is a known epigenetic modifier that demonstrated antitumor effect in different types of cancer. The poor solubility and metabolic stability are major drawbacks that limit its development as an antitumor agent. Dimethoxycurcumin (DMC) is a more soluble and stable curcumin analog. In this study, we compared the effect of both drugs on a variety of histone posttranslational modifications and on the activity of histone lysine methyltransferase (HKMTs) and demethylase (HKDMTs) enzymes that target the H3K4, H3K9 and H3K27 epigenetic marks. Mass spectrometry was used to quantitate the changes in 95 histone posttranslational modifications induced by curcumin or DMC. The effect of both drugs on the enzymatic activity of HKMTs and HKDMs was measured using an antibody-based assay. Mass spectrometry analysis showed that curcumin and DMC modulated several histone modifications. Histone changes were not limited to lysine methylation and acetylation but included arginine and glutamine methylation. Only few histone modifications were similarly changed by both drugs. On the contrary, the effect of both drugs on the activity of HKMTs and HKDMs was very similar. Curcumin and DMC inhibited the HKMTs enzymes that target the H3K4, H3K9 and H3K27 marks and increased the activity of the HKDMs enzymes LSD1, JARID and JMJD2. In conclusion, we identified novel enzymatic targets for both curcumin and DMC that support their use and development as epigenetic modifiers in cancer treatment. The multiple targets modulated by both drugs could provide a therapeutic advantage by overcoming drug resistance development.

Topics: Curcumin; Histone-Lysine N-Methyltransferase; Histones; Humans; Leukemia

Curcumin (Cur), is a pigment with antiproliferative activity but has some pharmacokinetic limitations, which led researchers to look for more effective structure analogs. This work investigated the effects of Cur and compared them with the two analogs, demethoxycurcumin (DeMC) and dimethoxycurcumin (DiMC), to elucidate their mechanisms of action. The cytotoxic, antiproliferative, and genotoxic effects these compounds were correlated based on gene expression analysis in the human renal adenocarcinoma cells (786-O). Cur decreased CYP2D6 expression and exhibited cytotoxic effects, such as inducing monopolar spindle formation and mitotic arrest mediated by the increase in CDKN1A (p21) mRNA. This dysregulation induced cell death through a caspase-independent pathway but was mediated by decrease in MTOR and BCL2 mRNA expression, suggesting that apoptosis occurred by autophagy. DeMC and DiMC had similar effects in that they induced monopolar spindle and mitotic arrest, were genotoxic, and activated GADD45A, an important molecule in repair mechanisms, and CDKN1A. However, the induction of apoptosis by DeMC was delayed and regulated by the decrease of antiapoptotic mRNA BCL.XL and subsequent activation of caspase 9 and caspase 3/7. DiMC treatment increased the expression of CYP1A2, CYP2C19, and CYP3A4 and exhibited higher cytotoxicity compared with other compounds. It induced apoptosis by increasing mRNA expression of BBC3, MYC, and CASP7 and activation of caspase 9 and caspase 3/7. These data revealed that different gene regulation processes are involved in cell death induced by Cur, DeMC, and DiMC. All three can be considered as promising chemotherapy candidates, with DiMC showing the greatest potency.

Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Survival; Comet Assay; Curcumin; Diarylheptanoids; Gene Expression Regulation, Neoplastic; Humans; Kidney Neoplasms; Spindle Apparatus

Dimethoxycurcumin (DiMC), a synthetic analog of curcumin, was shown to have antiproliferative activity in human tumor cell lines. Therefore, we investigated its cytotoxic, antiproliferative, genotoxic, and apoptotic effect and correlated these evaluations with the expression of transcripts and proteins in the human hepatocellular carcinoma cell line (HepG2/C3A). Treatment with DiMC resulted in increased CYP2E1, CYP2C19 and CYP1A2 transcripts levels and was cytotoxic (≥10 μM). DiMC caused mitotic arrest by inducing monopolar spindle formation and was genotoxic increasing expression of the CDKN1A, GADD45A and PARP1 gene, key effectors in the cell cycle arrest and DNA repair pathways, respectively. This genotoxicity was caused by generation of reactive oxygen species and reduction of antioxidant proteins levels. Furthermore, we observed a decrease in important proteins involved in DNA repair. In addition to the observed apoptotic morphology and the presence of annexin labeling, we observed increased expression of BAK1 and CASP7 genes and caspase 3/7 protein activity, showing that these effects caused apoptosis through the intrinsic pathway in HepG2/C3A cells. Our results indicate that DiMC modulates important molecular targets leading to cell death even in metabolic competent cells models has considerable potential in anticancer therapy.

Topics: Antineoplastic Agents; Apoptosis; Cell Proliferation; Curcumin; Cytochrome P-450 Enzyme System; DNA Damage; Gene Expression Regulation, Neoplastic; Hep G2 Cells; Humans; Mutagens; Spindle Apparatus

The curcumin-C3 (cur-C3) complex obtained from Curcuma longa rhizome is a combination of three curcuminoids, namely, curcumin, dimethoxycurcumin, and bisdemethoxycurcumin. Cur and curcuminoids have been extensively researched for their wide range of therapeutic properties against inflammatory diseases, diabetes, and cancer.. In spite of their extensive medicinal properties, cur and curcuminoids have poor solubility and bioavailability due to their hydrophobicity. This limitation can be overcome by complexing cur-C3 with natural cyclic oligosaccharides, such as Cyclodextrin (CD).. In this study, cur-C3 and CD (α, β) inclusion complexes (ICs) were prepared with different molar ratios and characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, X-ray diffraction, and transmission electron microscopy.. The cur-C3 cyclodextrin ICs showed an increased entrapment efficiency of 97.8% and improved antioxidant activity compared to cur and can be used as an antioxidant to reduce cancer-related oxidative stress. Additionally, α- CD ICs of curcumin-C3 caused an increase in growth inhibition of Staphylococcus aureus.. Our findings suggest that both α- and β-CDs are suitable carriers for cur-C3 and can be used as an effective treatment for cancer-associated oxidative stress and as a preventive treatment for nosocomial infections and pneumonia.

Topics: alpha-Cyclodextrins; Anti-Bacterial Agents; Antioxidants; beta-Cyclodextrins; Biological Availability; Curcumin; Diarylheptanoids; Drug Compounding; Escherichia coli; Hydrophobic and Hydrophilic Interactions; Solubility; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction

Tagetes lucida Cav. is an ancient medicinal plant used to treat different ailments involving neurological diseases and pain. However, scientific studies to validate their medicinal properties as analgesic have not been described. The aim of this study was to evaluate the T. lucida antinociceptive response using pain models. Bioactive compounds and a possible mechanism of action were also explored. Dose-response effects of an ethanol crude extract were investigated in the writhing and formalin tests in mice and rats, respectively. The extract was fractionated to isolate active fractions and bioactive compounds (quercetagetin 7‑O‑β‑d‑glucoside and 6,7‑dimethoxycoumarin) using the formalin test. The antinociceptive effects were compared to the reference drugs (tramadol 10 mg/kg, diclofenac 50 mg/kg, and/or ketorolac 1 mg/kg, i.p.). The ethanol extract was explored in the presence of naloxone (3 mg/kg, i.p. a non-selective opioid receptor antagonist) and WAY100635 (0.5 mg/kg, s.c., a selective 5-HT

Topics: Analgesics; Animals; Curcumin; Female; Flavones; Male; Medicine, Chinese Traditional; Mice; Models, Animal; Naloxone; Narcotic Antagonists; Pain; Plant Extracts; Plant Leaves; Rats; Rats, Wistar; Receptor, Serotonin, 5-HT1A; Tagetes

Curcumin is a polyphenol derived from the herb Curcuma longa, which has been extensively studied in terms of its antitumour, antioxidant, and chemopreventive activity as well as various other effects. In the present work we compared curcumin with its synthetic analogue dimethoxycurcumin (dimc) in terms of its antioxidant enzyme-modulating effects in human peripheral blood mononuclear cells (PBMC). We found that these compounds modulate antioxidant enzymes differentially. Both curcumin and dimethoxycurcumin effected a decrease in lipid peroxidation status in PBMC, however, curcumin had better activity in this regard. An increase in the activity of catalase was seen in the case of curcumin-treated PBMC, whereas dimc increased catalase activity significantly to almost twofold level. Real time-polymerase chain reaction (RT-PCR) analysis revealed significant up-regulation of catalase at mRNA level post treatment with curcumin as well as dimc, however, dimc had better activity in this regard. Glutathione reductase (GR) activity and reduced glutathione levels increased in the case of peripheral blood mononuclear cells (PBMC) treated with curcumin, however, the trend was reversed with dimethoxycurcumin where, both glutathione reductase activity and reduced glutathione levels were significantly reduced. RT-PCR analysis of glutathione reductase mRNA levels showed decrease in mRNA levels post treatment with dimethoxycurcumin (dimc) further corroborating GR enzyme assay results, however, we could not obtain significant result post curcumin treatment. NFkB reporter assay and western blot analysis of nuclear as well as cytosolic fractions of NFkB revealed that curcumin inhibits NFkB activation whereas inhibition was much less with dimc. It has been reported that curcumin and dimc exerts differential cytotoxicity in normal and tumour cells and the reason for this had been attributed to the differential uptake of these compounds by normal cells and tumour cells. Based on our results we propose that differential modulation of antioxidant enzymes via NFkB pathway could be the reason behind differential cytotoxicity of dimc as well as curcumin in normal cells and tumour cells in addition to differential uptake of these compounds as reported previously.

Topics: Antioxidants; Catalase; Curcumin; Gene Expression Regulation; Glutathione; Glutathione Reductase; Humans; Leukocytes, Mononuclear; Lipid Peroxidation; NF-kappa B; Primary Cell Culture; Signal Transduction

Topics: Animals; Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Cell Cycle; Cell Line, Tumor; Cell Survival; Colonic Neoplasms; Curcumin; Dose-Response Relationship, Drug; Drug Synergism; Endoplasmic Reticulum; Fluorouracil; Humans; Membrane Potential, Mitochondrial; Mice; Reactive Oxygen Species; Signal Transduction

Dimethoxycurcumin (DIMC), a structural analogue of curcumin, has been shown to have more stability, bioavailability, and effectiveness than its parent molecule curcumin. In this paper the radiosensitizing effect of DIMC has been investigated in A549 lung cancer cells. As compared to its parent molecule curcumin, DIMC showed a very potent radiosensitizing effect as seen by clonogenic survival assay. DIMC in combination with radiation significantly increased the apoptosis and mitotic death in A549 cells. This combinatorial treatment also lead to effective elimination of cancer stem cells. Further, there was a significant increase in cellular ROS, decrease in GSH to GSSG ratio and also significant slowdown in DNA repair when DIMC was combined with radiation. In silico docking studies and in vitro studies showed inhibition of thioredoxin reductase enzyme by DIMC. Overexpression of thioredoxin lead to the abrogation of radiosensitizing effect of DIMC underscoring the role of thioredoxin reductase in radiosensitization. Our results clearly demonstrate that DIMC can synergistically enhance the cancer cell killing when combined with radiation by targeting thioredoxin system.

Topics: A549 Cells; Antineoplastic Agents; Apoptosis; Chemoradiotherapy; Curcumin; Dose-Response Relationship, Drug; Humans; Neoplasms, Experimental; Radiation Tolerance; Radiation-Sensitizing Agents; Reactive Oxygen Species; Thioredoxin-Disulfide Reductase; Treatment Outcome

The presence of β-amyloid (Aβ) containing plaques in the brain is a hallmark of Alzheimer's disease (AD) and serves as a biomarker for confirmation of diagnosis postmortem. Early diagnosis is of great importance for optimal treatment and for monitoring disease progression in the brain. Highly specific and sensitive biomarkers are thus greatly needed to assess therapeutic efficacy, not only clinically, but also in terms of clearance of histopathological lesions and decelerated neurodegeneration. The objective of the present study was to give more insight into the binding of curcumin analogues, curcuminoids, to Aβ containing plaques in postmortem tissue from AD patients. In vitro autoradiography was utilized to explore affinity and displacement of the curcuminoids; curcumin, demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC) and dimethoxycurcumin (DIMC). We found that BDMC had the highest affinity for Aβ containing plaques in cortical AD brain tissue in comparison to other curcuminoids. Subsequently, [(3)H]BDMC showed significantly higher specific binding in cortical AD brain tissue compared to control subjects. These findings suggest that curcumin analogues, especially BDMC, may serve as a potential radioligands for Aβ plaque neuroimaging.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Aminopyridines; Amyloid beta-Peptides; Autoradiography; Benzothiazoles; Curcumin; Diarylheptanoids; Female; Humans; Inhibitory Concentration 50; Male; Temporal Lobe

The B-cell-specific Moloney murine leukemia virus integration site 1 (BMI1) locus encodes a 37-kD protein that is a key regulatory component of the polycomb regulatory complex 1 (PRC1). When overexpressed in various cancer types, the BMI1 protein induces cell growth and promotes tumor growth in vitro and in vivo. Curcumin, a major phytochemical in turmeric (Curcuma longa), inhibits the proliferation and survival of many types of cancer cells, both in vitro and in vivo, and has been reported to reduce BMI1 expression in breast cancer cells. In this study, effects of curcumin and two analogs (bisdemethoxycurcumin and dimethoxycurcumin) on BMI1 expression were evaluated in DLD-1 colorectal cancer cells. Bisdemethoxycurcumin (BDMC) is naturally occurring in turmeric, whereas dimethoxycurcumin (DMC) is a synthetic analog of curcumin. All three compounds reduced cell survival, but only the natural compound downregulated BMI1 protein expression; curcumin significantly reduced BMI1 levels more than bisdemethoxycurcumin and dimethoxycurcumin. In addition, curcumin and BDMC inhibit survival of the DLD-1 colorectal cancer cells by inducing apoptosis, whereas DMC inhibits survival by a mechanism other than apoptosis.

Topics: Adult; Antineoplastic Agents; Apoptosis; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cell Survival; Colorectal Neoplasms; Curcumin; Diarylheptanoids; Down-Regulation; Humans; Male; Polycomb Repressive Complex 1

BACKGROUND Dimethoxy curcumin (DMC) is a kind of lipophilic analog of curcumin with great improvement in chemical and metabolic stability. DMC has been studied in breast and renal cancer, but no research in colon cancer has been found yet. MATERIAL AND METHODS Two colon cancer cells (HT-29 and SW480) and one normal human colon mucosal epithelial cell (NCM460) were used in this study. We studied the effect of DMC on the proliferation in vitro and in vivo. Transwell migration assay was used to estimate the inhibition of DMC on invasion. Moreover, the expressions of PARP, caspase-3, survivin and E-cadherin were detected to uncover the related signaling pathways by western blotting assay both in vitro and in vivo. RESULTS DMC significantly inhibited the growth of colon cancer cells in dose-dependent manner; IC50 for DMC was calculated to be 43.4, 28.2 and 454.8µM on HT-29, SW480 and NCM460. DMC significantly increased the apoptosis in both HT-29 (p=0.0051) and SW480 (p=0.0013) cells in vitro, and significantly suppressed the growth of both cell lines in vivo. Moreover, DMC reduced the number of migrated cells in both HT-29 (p=0.007) and SW480 (p=0.004) cells. By western blotting analysis, the cleavage of pro-caspases-3 and PARP were clearly induced by DMC to their active form, while the expression of survivin was reduced and E-cadherin was enhanced in both cells in vitro and in vivo. CONCLUSIONS DMC may exert an effective anti-tumor effect in colon cancer cells by down-regulating survivin and upregulating E-cadherin.

Topics: Animals; Antigens, CD; Antineoplastic Agents; Apoptosis; Cadherins; Caspase 3; Cell Line, Tumor; Cell Movement; Cell Proliferation; Colonic Neoplasms; Curcumin; Female; Humans; Inhibitor of Apoptosis Proteins; Mice, Inbred BALB C; Mice, Nude; Neoplasm Invasiveness; Poly(ADP-ribose) Polymerases; Survivin; Xenograft Model Antitumor Assays

Curcumin is an ideal chemopreventive and antitumor agent characterized by poor bioavailability and low stability. The development of synthetic structural analogues like dimethoxycurcumin (DMC) could overcome these drawbacks. In this study we compared the cytotoxicity, metabolism and the epigenetic changes induced by both drugs in leukemia cells.. Apoptosis and cell cycle analysis were analyzed by flow cytometry. Real-time PCR was used for gene expression analysis. DNA methylation was analyzed by DNA pyrosequencing. The metabolic stability was determined using human pooled liver microsomes. Chromatin Immunoprecipitation was used to quantify histone methylation.. Clinically relevant concentration of curcumin and DMC were not cytotoxic to leukemia cells and induced G2/M cell cycle arrest. DMC was more metabolically stable than curcumin. Curcumin and DMC were devoid of DNA hypomethylating activity. DMC induced the expression of promoter methylated genes without reversing DNA methylation and increased H3K36me3 mark near the promoter region of hypermethylated genes.. DMC is a more stable analogue of curcumin that can induce epigenetic changes not induced by curcumin. DMC induced the expression of promoter methylated genes. The combination of DMC with DNA methyltransferase inhibitors could harness their combined induced epigenetic changes for optimal re-expression of epigenetically silenced genes.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Biotransformation; Cell Line, Tumor; Curcumin; DNA Methylation; Dose-Response Relationship, Drug; Drug Stability; Epigenesis, Genetic; G2 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Leukemic; Histones; Humans; Leukemia; Methylation; Microsomes, Liver; Promoter Regions, Genetic; Time Factors

Prostate cancer (PCa) is the most commonly diagnosed cancer in men worldwide. It is essentially dependent on potent androgens, such as testosterone (T) and dihydrotestosterone (DHT). The precursors of T and DHT, which includes androstenedione (A4) and dihydroepiandrosterone (DHEA), and also the metabolites of DHT, 5α-androstane-3α,17β-diol (3α-Diol) and 5α-androstane-3β,17β-diol (3β-Diol) are able to affect the development of PCa. Therefore, it is important to simultaneously determine all these key androgens. This study aims to develop and validate an LC-MS/MS quantification method to simultaneously detect and quantify the six related androgens, including T, DHT, A4, DHEA, 3α-Diol, and 3β-Diol in limited sample volume. The sample preparation involved liquid extraction with methyl tert-butyl ether (MTBE), following by chemical derivatisation with hydroxylamine. The limits of quantitation for T, DHT, A4, and DHEA were 0.05nM and 3α-Diol and 3β-Diol were 0.5nM with S/N ratio of at least 5:1 by using 100μL samples.

Topics: Androgens; Animals; Antineoplastic Agents; Chromatography, Liquid; Curcumin; Hydroxylamine; Liquid-Liquid Extraction; Male; Methyl Ethers; Mice, Inbred C57BL; Reproducibility of Results; Tandem Mass Spectrometry

Dimethoxycurcumin (DMC) is an analog of curcumin with superior efficacy in various disease models. Currently, drug delivery system research on DMC is very limited, and it has become a huge challenge to realize further developments and clinical applications. In the present study, a kind of amphiphilic block copolymer, N-t-butoxycarbonyl-phenylalanine terminated monomethoxyl poly (ethylene glycol)-b-poly (ε-caprolactone), or mPEG-PCL-Phe(Boc), was prepared from monomethoxyl poly (ethylene glycol)-b-poly (ε-caprolactone) (mPEG-PCL) with its hydroxyl terminal chemically converted into N-t-butoxycarbonyl-phenylalanine (Boc-Phe). This copolymer was determined to have a fairly low critical micelle concentration (2.56×10(-3) mg/mL) and passive targeting potential to tumor tissue, and thus was applied to develop a polymeric micellar formulation of DMC for the first time. The DMC-loaded micelles prepared by thin-film hydration method had typical shell-core structure, with an average particle size of 17.9±0.4 nm and a polydispersity index of 0.045±0.011. The drug loading capacity and entrapment efficiency were 9.94%±0.15% and 97.22%±0.18%, respectively, indicating a high-affinity interaction between DMC and the copolymer. At a concentration of 2 mg/mL, the reconstituted micelle solution could be maintained for at least 10 days at room temperature, and displayed a low initial burst release followed by a sustained release in vitro. Pharmacokinetic study in rats revealed that in vivo drug exposure of DMC was significantly increased and prolonged by intravenously administering DMC-loaded micelles when compared with the same dose of free DMC dissolved in dimethyl sulfoxide. Furthermore, in vivo distribution results from tumor-bearing nude mice demonstrated that this micellar formulation significantly changed the biodistribution profile of DMC and increased drug accumulation in tumors. Therefore, the polymeric micellar formulation of DMC, based on the amphiphilic block copolymer, mPEG-PCL-Phe(Boc), could provide a desirable method for delivering DMC, especially for applications in cancer therapy.

Topics: Animals; Cell Line, Tumor; Chemistry, Pharmaceutical; Curcumin; Drug Carriers; Drug Liberation; Female; Humans; Male; Mice; Mice, Nude; Micelles; Particle Size; Polyesters; Polyethylene Glycols; Polymers; Rats; Temperature; Tissue Distribution

Mutation of TAR DNA-binding protein-43 (TDP-43) was detected in familiar and sporadic amyotrophic lateral sclerosis, and pathological TDP-43 was identified in the frontotemporal lobar degeneration. The neuroprotective functions of curcumin derivatives were assessed in motor neurons transfected with mutant TDP-43. We found that curcumin derivatives reduced the levels of TDP-43 fragments. Furthermore, we evaluated these compounds on the cellular model that the cells were transfected with TDP-25. We found that the expression level and aggregate formation of TDP-25 were significantly reduced by monocarbonyl dimethoxycurcumin C (Compound C). To study on the neuroprotective functions of curcumin derivatives, the neuroblastoma-spinal cord-34 cells transfected with mutant TDP-43 were assessed by the level of lactate dehydrogenase (LDH) and malondialdehyde bisdimethyl acetal (MDA) that were involved in the oxidative stress. We found that Compound C ameliorated the damage of mutant TDP-43 by reducing the level of MDA and LDH. Furthermore, heme oxygenase-1 (HO-1) was induced by Compound C significantly higher than other compounds. Znpp, which is known an inhibitor of HO-1, dramatically interfered with the function of Compound C. In addition, Compound C was tested in vivo, and HO-1 was significantly upregulated at the hippocampus. These findings suggest that Compound C, which degrades TDP-43 fragment and strengthens the antioxidant ability by HO-1, is a promising agent for TDP-43 proteinopathy.

Topics: Animals; Cell Line; Curcumin; DNA-Binding Proteins; Dose-Response Relationship, Drug; Heme Oxygenase-1; Humans; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Mutation; Neuroprotective Agents; Oxidative Stress

Although curcumin suppresses the growth of a variety of cancer cells, its poor absorption and low systemic bioavailability have limited its translation into clinics as an anticancer agent. In this study, we show that dimethoxycurcumin (DMC), a methylated, more stable analog of curcumin, is significantly more potent than curcumin in inducing cell death and reducing the clonogenicity of malignant breast cancer cells. Furthermore, DMC reduces the tumor growth of xenografted MDA-MB 435S cells more strongly than curcumin. We found that DMC induces paraptosis accompanied by excessive dilation of mitochondria and the endoplasmic reticulum (ER); this is similar to curcumin, but a much lower concentration of DMC is required to induce this process. DMC inhibits the proteasomal activity more strongly than curcumin, possibly causing severe ER stress and contributing to the observed dilation. DMC treatment upregulates the protein levels of CCAAT-enhancer-binding protein homologous protein (CHOP) and Noxa, and the small interfering RNA-mediated suppression of CHOP, but not Noxa, markedly attenuates DMC-induced ER dilation and cell death. Interestingly, DMC does not affect the viability, proteasomal activity or CHOP protein levels of human mammary epithelial cells, suggesting that DMC effectively induces paraptosis selectively in breast cancer cells, while sparing normal cells. Taken together, these results suggest that DMC triggers a stronger proteasome inhibition and higher induction of CHOP compared with curcumin, giving it more potent anticancer effects on malignant breast cancer cells.

Topics: Animals; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Cell Proliferation; Cell Survival; Curcumin; Dose-Response Relationship, Drug; Female; Humans; Male; MCF-7 Cells; Mice; Mice, Inbred BALB C; Mice, Nude; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Proto-Oncogene Proteins c-bcl-2; RNA Interference; Time Factors; Transcription Factor CHOP; Transfection; Tumor Burden; Up-Regulation; Xenograft Model Antitumor Assays

Dimethoxycurcumin (DMC) is a lipophilic analog of curcumin found in Curcuma longa Linn., which is known to possess significant activity against various cancer cell lines. The purpose of this study was to develop suitable liposomal formulations in order to overcome DMC's poor water solubility and to study the aggregation kinetic profile using the fractal analysis. DMC was incorporated into liposomal formulations composed of DPPC, DPPC:DPPG:chol (9:1:1 molar ratio) and DPPC:DODAP:chol (9:1:1 molar ratio) liposomes. Light scattering techniques were used to elucidate the physicochemical parameters of the liposomal formulations with and without DMC. The structural characteristics of the incorporated molecule were found to be crucial and promote the aggregation mechanism depending also on the liposomes' composition. The results of our study contribute to the overall scientific efforts to prepare efficient carriers for DMC and could be a useful tool in order to study more efficiently the kinetics of the aggregation process of the liposomal carriers.

Topics: Curcumin; Fractals; Kinetics; Liposomes; Scattering, Radiation

Dimethoxy curcumin (DMC) is a methylated derivative of curcumin. In order to know the effect of ring substitution on photophysical properties of curcumin, steady state absorption and fluorescence spectra of DMC were recorded in organic solvents with different polarity and compared with those of curcumin. The absorption and fluorescence spectra of DMC, like curcumin, are strongly dependent on solvent polarity and the maxima of DMC showed red shift with increase in solvent polarity function (Δf), but the above effect is prominently observed in case of fluorescence maxima. From the dependence of Stokes' shift on solvent polarity function the difference between the excited state and ground state dipole moment was estimated as 4.9 D. Fluorescence quantum yield (φ(f)) and fluorescence lifetime (τ(f)) of DMC were also measured in different solvents at room temperature. The results indicated that with increasing solvent polarity, φ(f) increased linearly, which has been accounted for the decrease in non-radiative rate by intersystem crossing (ISC) processes.

Topics: Antineoplastic Agents, Phytogenic; Antioxidants; Curcuma; Curcumin; Solvents; Spectrometry, Fluorescence; Spectrophotometry

The factors responsible for the induction of cell death by dimethoxycurcumin (Dimc), a synthetic analog of curcumin, were assessed in human breast carcinoma MCF7 cells. Initial cytotoxic studies with both curcumin and Dimc using MTT assay indicated their comparable effects. Further, the mechanism of action was explored in terms of oxidative stress, mitochondrial dysfunction, and modulation in the expression of proteins involved in cell cycle regulation and apoptosis. Dimc (5-50 μM) caused generation of reactive oxygen species, reduction in glutathione level, and induction of DNA damage. The mitochondrial dysfunction induced by Dimc was evidenced by the reduction in mitochondrial membrane potential and decrease in cellular energy status (ATP/ADP) monitored by HPLC analysis. The observed decrease in ATP was also supported by the significant suppression of different (α, β, γ, and ε) subunits of ATP synthase. The cytotoxic effect of Dimc was further characterized in terms of induction of S-phase cell cycle arrest and apoptosis, and their relative contribution was found to vary with the treatment concentration of Dimc. The S-phase arrest and apoptosis could also be correlated with the changes in the expressions of cell cycle proteins like p53, p21, CDK4, and cyclin-D1 and apoptotic markers like Bax and Bcl-2. Overall, the results demonstrated that Dimc induced cell death in MCF7 cells through S-phase arrest and apoptosis.

Topics: Antineoplastic Agents; Antioxidants; Apoptosis; Breast Neoplasms; Cell Cycle Proteins; Cell Line, Tumor; Cell Survival; Curcumin; Drug Screening Assays, Antitumor; Female; Humans; Membrane Potential, Mitochondrial; Mitochondria; Reactive Oxygen Species; S Phase Cell Cycle Checkpoints

Curcumin, the most active compound of curcuminoids, has been shown to inhibit formation of advanced glycation end products (AGEs) in streptozotocin-induced diabetic rats. However, little is known on whether curcumin may trap methylglyoxal (MGO), a major reactive dicarbonyl compound, to inhibit AGE formation. We found that one molecule of curcumin effectively trapped one molecule of MGO at a 1:3 ratio at 24 h of incubation under physiological conditions (pH 7.4, 37 °C). Curcumin decreased N(ε)-(carboxymethyl)lysine (CML) expression in human umbilical vein endothelial cells. We further used two curcumin analogues, dimethoxycurcumin (DIMC) and ferulic acid, to investigate the possible MGO-trapping mechanism of curcumin. Results reveal that DIMC, but not ferulic acid, exhibited MGO-trapping capacity, indicating curcumin traps MGO at the electron-dense carbon atom (C10) between the two keto carbon groups. Thus, curcumin may prevent MGO-induced endothelial dysfunction by directly trapping MGO.

Topics: Animals; Blotting, Western; Cell Proliferation; Cell-Free System; Chromatography, High Pressure Liquid; Coumaric Acids; Curcumin; Diabetes Mellitus, Experimental; Glycation End Products, Advanced; Human Umbilical Vein Endothelial Cells; Humans; Hydrogen-Ion Concentration; Pyruvaldehyde; Rats; Tandem Mass Spectrometry

TAR-DNA-binding protein of 43kDa (TDP-43) was recently found to be one of the major disease proteins in the pathological inclusions of amyotrophic lateral sclerosis (ALS). The effect of TDP-43 on mitochondrial function remains poorly understood. Here, we show that human TDP-43 caused mitochondrial morphologic abnormality, decrease of mitochondrial complex I activity and mitochondrial transmembrane potential, and increased expression of mitochondrial uncoupling protein 2 (UCP2) in human TDP-43 stably transfected NSC-34 cells by using flow cytometric analysis, spectrophotometric assays, electron microscopy and Western blotting. We also show that dimethoxy curcumin (DMC) could ameliorate mitochondrial dysfunction in mutated TDP-43 stably transfected cell lines. DMC could be potentially useful for neurodegenerative diseases linked with mutated TDP-43.

Topics: Cell Line; Curcumin; Cytoprotection; DNA-Binding Proteins; Humans; Mitochondria; Transfection

Three curcumin analogues viz., bisdemethoxy curcumin, monodemethoxy curcumin, and dimethoxycurcumin that differ at the phenolic substitution were synthesized. These compounds have been subjected for free radical reactions with DPPH radicals, superoxide radicals (O(2)(•-)), singlet oxygen ((1)O(2)) and peroxyl radicals (CCl(3)O(2)(•)) and the bimolecular rate constants were determined. The DPPH radical reactions were followed by stopped-flow spectrometer, (1)O(2) reactions by transient luminescence spectrometer, and CCl(3)O(2)(•) reactions using pulse radiolysis technique. The rate constants indicate that the presence of o-methoxy phenolic OH increases its reactivity with DPPH and CCl(3)O(2)(•), while for molecules lacking phenolic OH, this reaction is very sluggish. Reaction of O(2)(•-) and (1)O(2) with curcumin analogues takes place preferably at β-diketone moiety. The studies thus suggested that both phenolic OH and the β-diketone moiety of curcumin are involved in neutralizing the free radicals and their relative scavenging ability depends on the nature of the free radicals.

Topics: Biphenyl Compounds; Carbon Tetrachloride; Curcumin; Diarylheptanoids; Free Radical Scavengers; Free Radicals; Hydroxyl Radical; Peroxides; Picrates; Pulse Radiolysis; Reactive Oxygen Species; Singlet Oxygen; Spectrum Analysis; Structure-Activity Relationship; Superoxides

Dimethoxycurcumin (Dimc), a synthetic analogue of curcumin, that has been reported to exhibit better in vivo stability and anti-tumour activity, was investigated for its interaction with DNA, employing spectroscopic methods based on absorption, fluorescence, circular dichroism (CD), ethidium bromide (EtBr) competitive binding assay, 4'-6-diamidino-2-phenylindole (DAPI) displacement assay and fluorescence resonance energy transfer (FRET) assay. The mean binding constant for its interaction with calf thymus DNA (ct-DNA) was estimated to be 4.4±0.8 × 10(4) m(-1) . The studies using CD revealed that Dimc did not cause unwinding of the ct-DNA helix or induce major conformational changes. The EtBr and DAPI assays indicated that Dimc is not an intercalator but a minor groove binder. FRET assay also confirmed that Dimc interacts with DNA strands. Furthermore, viscosity measurements of ct-DNA solutions in the presence of Dimc supported these spectroscopic observations. Addition of Dimc to MCF-7 cells showed nuclear localization as visualized by confocal microscopy. In conclusion, the present studies addressed the mode of interaction of Dimc with biomolecules, which may have implications in developing Dimc as a DNA-targeted drug.

Topics: Animals; Circular Dichroism; Curcumin; DNA; Humans; Microscopy, Confocal; Molecular Structure; Spectrometry, Fluorescence

The aim of this study was to investigate whether dimethoxycurcumin (DiMC), a synthetic curcumin analogue having higher metabolic stability over curcumin, could exhibit anti-inflammatory activity in murine and human lymphocytes. Both curcumin and DiMC suppressed mitogen as well as antigen driven proliferation of murine splenic lymphocytes. Further, mitogen and antigen-stimulated cytokine (IL-2, IL-4, IL-6 and IFN-γ) secretion by T cells was also abrogated by curcumin and DiMC. Interestingly, curcumin and DiMC suppressed B cell proliferation induced by lipopolysaccharide. Curcumin and DiMC also inhibited Con A-induced activation of early and late T cell activation markers. They scavenged basal reactive oxygen species and depleted GSH levels in lymphocytes. The suppression of mitogen-induced T cell proliferation and cytokine secretion by curcumin and DiMC was significantly abrogated by thiol containing antioxidants suggesting a role for redox in their anti-inflammatory activity. Further, the possibility of curcumin and DiMC directly interacting with thiol-containing antioxidant GSH was monitored by changes in absorbance. Both curcumin and DiMC inhibited Con A induced activation of NF-κB and MAPK. More importantly, curcumin and DiMC inhibited phytohaemagglutinin induced proliferation and cytokine secretion by human peripheral blood mononuclear cells. To explore their therapeutic efficacy, they were added to lymphocytes post-Con A stimulation and we observed a significant suppression of IL-2, IL-6 and IFN-γ. The present study for the first time demonstrates the potent anti-inflammatory activity of DiMC. Further, DiMC could find application as an alternative to curcumin, which is currently used in several clinical studies, due to its superior bioavailability and comparable efficacy.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Blotting, Western; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Proliferation; Cell Survival; Curcumin; Cytokines; Flow Cytometry; Glutathione; Humans; Jurkat Cells; Leukocytes, Mononuclear; Male; Mice; Molecular Structure; Reactive Oxygen Species; Reverse Transcriptase Polymerase Chain Reaction; Species Specificity; Spleen

Excess production of nitric oxide (NO) by inducible NO synthase (iNOS) in activated macrophages is linked to acute and chronic inflammation. Thus, it would be valuable to develop inhibitors of NO and/or iNOS for potential therapeutic use. We investigated whether dimethoxycurcumin (DiMC), a synthetic curcumin analogue with higher metabolic stability over curcumin, could inhibit NO production and iNOS expression in activated macrophages. RAW264.7 macrophages were activated with lipopolysaccharide (LPS) in the absence or presence of DiMC, which contains four methoxy groups at two aromatic rings, curcumin containing two, bis-demethoxycurcumin (BDMC) containing none, or tetrahydrocurcumin (THC) containing two but lacking conjugated double bonds in the central seven-carbon chain. NO production, iNOS expression and NF-kappaB activity were examined. DiMC, curcumin and BDMC inhibited NO production, iNOS expression and NF-kappaB activation, with DiMC being the most effective, followed by curcumin and BDMC. THC failed to inhibit NO production, iNOS expression and NF-kappaB activation. Our results suggest that DiMC inhibits NO production, iNOS expression and NF-kappaB activation in LPS-activated macrophages, which may be due not only to the conjugated double bonds but also the increased number of methoxy groups.

Topics: Animals; Cell Line; Curcuma; Curcumin; DNA-Binding Proteins; Drug Stability; I-kappa B Kinase; Lipopolysaccharides; Macrophage Activation; Macrophages; Mice; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase Type II; Plant Roots

The plant-derived compound curcumin has shown promising abilities as a cancer chemoprevention and chemotherapy agent in vitro and in vivo but exhibits poor bioavailability. Therefore, there is a need to investigate modified curcumin congeners for improved anticancer activity and pharmacokinetic properties.. The synthetic curcumin analogue dimethoxycurcumin was compared with curcumin for ability to inhibit proliferation and apoptosis of human HCT116 colon cancer cells in vitro by estimating the GI(50) and LC(50) values and detecting the extent of apoptosis by flow cytometry analysis of the cell cycle. Metabolic stability and/or identification of metabolites were evaluated by recently developed mass spectrometric approaches after incubation with mouse and human liver microsomes and cancer cells in vitro. Additionally, circulating levels of dimethoxycurcumin and curcumin were determined in mice following i.p. administration.. Dimethoxycurcumin is significantly more potent than curcumin in inhibiting proliferation and inducing apoptosis in HCT116 cells treated for 48 h. Nearly 100% of curcumin but <30% of dimethoxycurcumin was degraded in cells treated for 48 h, and incubation with liver microsomes confirmed the limited metabolism of dimethoxycurcumin. Both compounds were rapidly degraded in vivo but dimethoxycurcumin was more stable.. Compared with curcumin, dimethoxycurcumin is (a) more stable in cultured cells, (b) more potent in the ability to kill cancer cells by apoptosis, (c) less extensively metabolized in microsomal systems, and (d) more stable in vivo. It is likely that the differential extent of apoptosis induced by curcumin and dimethoxycurcumin in vitro is associated with the metabolite profiling and/or the extent of stability.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Growth Processes; Colonic Neoplasms; Curcumin; Drug Screening Assays, Antitumor; Drug Stability; Female; Flow Cytometry; HCT116 Cells; Humans; Male; Mice; Microsomes, Liver

Dimethoxycurcumin, a lipophilic analog of curcumin found as a major pigment in the Indian species turmeric (Curcuma longa Linn.), is known to possess significant activity against various cancer cell lines, but its use as an anticancer drug is hindered by its poor water solubility. The conjugation of dimethoxycurcumin to water-soluble PAMAM dendrimers (generations 3.5 and 4) is demonstrated. The maximum drug-dendrimer incorporation efficiency is 4.3 and 5.0 molar for G3.5 and G4, respectively. The FTIR-ATR investigation of the neat compounds and the drug-dendrimer systems indicate that dimethoxycurcumin is in the enolic form, while its interaction with the integer generation dendrimer involves the major conformational change of the terminal ethylene amine groups.

Topics: Chemistry, Pharmaceutical; Curcumin; Dendrimers; Drug Carriers; Polyamines; Spectroscopy, Fourier Transform Infrared