Multi-targeted therapy by curcumin: how spicy is it?

Combination treatment with highly bioavailable curcumin and NQO1 inhibitor exhibits potent antitumor effects on esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most intractable cancers, so the development of novel therapeutics has been required to improve patient outcomes. Curcumin, a polyphenol from Curcuma longa, exhibits various health benefits including antitumor effects, but its clinical utility is limited because of low bioavailability. Theracurmin^® (THC) is a highly bioavailable curcumin dispersed with colloidal submicron particles.

METHODS

We examined antitumor effects of THC on ESCC cells by cell viability assay, colony and spheroid formation assay, and xenograft models. To reveal its mechanisms, we investigated the levels of reactive oxygen species (ROS) and performed microarray gene expression analysis. According to those analyses, we focused on NQO1, which involved in the removal of ROS, and examined the effects of NQO1-knockdown or overexpression on THC treatment. Moreover, the therapeutic effect of THC and NQO1 inhibitor on ESCC patient-derived xenografts (PDX) was investigated.

RESULTS

THC caused cytotoxicity in ESCC cells, and suppressed the growth of xenografted tumors more efficiently than curcumin. THC increased ROS levels and activated the NRF2-NMRAL2P-NQO1 expressions. Inhibition of NQO1 in ESCC cells by shRNA or NQO1 inhibitor resulted in an increased sensitivity of cells to THC, whereas overexpression of NQO1 antagonized it. Notably, NQO1 inhibitor significantly enhanced the antitumor effects of THC in ESCC PDX tumors.

CONCLUSIONS

These findings suggest the potential usefulness of THC and its combination with NQO1 inhibitor as a therapeutic option for ESCC.

The protective role of melatonin and curcumin in the testis of young and aged rats

We aimed to investigate the effect of melatonin and curcumin treatment on oxidative stress, apoptosis, and histology of testicular tissue in our study. Four groups were formed using young (4 months old, n = 6) and aged (20-22 months old, n = 18) male Wistar albino rats: (a) Young control (1% ethanol:phosphate-buffered saline [PBS], subcutaneously [s.c.]); (b) Aged control (CTL; n = 6, 1% ethanol:PBS, s.c.); (c) Aged Melatonin (MLT; n = 6, 10 mg/kg, s.c.); (d) Aged Curcumin (CUR; n = 6, 30 mg/kg, i.p.). At the end of 21 days, the rats were sacrificed, and testicular tissues were removed. Malondialdehyde (MDA) in the testicular tissue was determined with thiobarbituric acid reactive substances formation, and glutathione (GSH) was determined with modified Ellman method; testosterone level was determined with chemiluminescence method and histologic changes were determined with Haematoxylin-Eosin and Johnsen's scoring; Apoptotic cell counts were made with TUNEL staining of seminiferous tubule in testis. With ageing, MDA level increased in testicular tissue, but GSH and blood testosterone levels decreased. Melatonin treatment for aged rats significantly decreased Paired total testicular/body weight ratio compared to aged control group (p < 0.05). Curcumin treatment for aged rats significantly increased GSH level compared to the aged control group (p < 0.05). Besides, melatonin and curcumin treatment significantly decreased the number of apoptotic cells and significantly increased Johnsen's score (p < 0.05).

Potential therapeutic effects of curcumin in gastric cancer

Despite recent advancements in understanding of the biology of gastric cancer, treatment of patients with advanced gastric cancer remains a major problem. Among different type of phytochemicals, curcumin, a welltable -known phytochemical, has been shown to be a promising cancer chemopreventive agent. Pharmacokinetics, safety, and efficacy of curcumin have been evaluated in several clinical trials against numerous diseases, and for the treatment of human cancer. In the present review, we have collected in vitro and in vivo investigations and studied the chemosensitizing and anticancer effects of curcumin against the gastric cancer cells. In summary, curcumin has been found to have efficient chemosensitizing effect and also inhibits viability, proliferation, and migration of gastric cancer cells mainly via cell cycle arrest and induction of apoptosis by both mitochondrial-dependent and -independent pathways.

Is boiled food spice curcumin still biologically active? An experimental exploration

Background

As the major active component of turmeric (Curcuma longa), curcumin is widely used as a spice and food coloring agent, and also possesses multiple biological activities and therapeutic potential for neurodegenerative diseases. To answer the paradox between curcumin’s biological activities and poor systemic bioavailability, we proposed that degradation products of curcumin may make important contributions to its biological activities, which needs to be verified. In addition, curcumin is usually heated or boiled used as a spice, it is necessary to explore whether boiled curcumin, which degrades readily, is still biologically active.

Methods

Thus, in the present study we investigated the protective effects of curcumin and boiled curcumin mixture on H2O2-induced oxidative damage in PC12 cells, a widely used model for neurons.

Results

Results showed that in spite of high degradation rates, boiled curcumin mixture still possessed similar protective activities like parent curcumin, and could effectively rescue PC12 cells against H2O2-induced damage, via decreasing production of reactive oxygen species and malondialdehyde, reducing caspase-3 and caspase-9 activities. Moreover, curcumin’s degradation products including ferulic acid, vanillin and vanillic acid could also improve PC12 cells survival rate.

Conclusion

Our findings indicated that boiled curcumin mixtures still possessed protective activity for PC12 cells, and supported the contribution of degradation products to biological activities of curcumin.

Curcumin formulated in solid lipid nanoparticles has enhanced efficacy in Hodgkin's lymphoma in mice

Curcumin reduces Hodgkin's lymphoma (HL) cell growth in vitro, but its unfavorable pharmacokinetics highlight the need for novel in vivo delivery systems. Thus, we explored whether formulation of curcumin in solid lipid nanoparticles (SLN-curc) or d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS) nanoparticles (TPGS-curc) could enhance its efficacy in mice. Curcumin formulated in SLN and in TPGS resulted in higher curcumin plasma levels in mice. Compared to vehicle-treated controls, SLN-curc and TPGS-curc reduced HL xenograft growth by 50.5% (p < 0.02) and 43.0% (p < 0.04), respectively, while curcumin reduced it by 35.8% (p < 0.05). In addition, SLN-curc reduced the expression of proteins involved in cell proliferation and apoptosis (XIAP and Mcl-1) in HL tumor extracts. In HL cells in culture, curcumin decreased the expression of relevant anti-inflammatory cytokines (IL-6 and TNF-α) in a concentration-dependent manner. Moreover, when given in combination with bleomycin, doxorubicin and vinblastine, curcumin showed an additive growth inhibitory effect. In conclusion, SLNs appear as an appropriate and effective drug delivery system for curcumin. Given the efficacy of SLN-curc and the enhanced growth inhibitory effect when combined with chemotherapeutic drugs, we speculate that curcumin, when appropriately formulated, is a promising adjuvant agent for the treatment of HL and merits further evaluation.

Role of Vital Trace Elements in Nanocurcumin-Centered Formulation: A Novel Approach to Resuscitate the Immune System

The present paper described the immunomodulatory potential of novel nanocurcumin-based formulation enriched with trace elements and vitamins on cyclophosphamide-induced immunosuppression in rat model. Major immune-related assays were monitored such as hemagglutination assay, delayed-type hypersensitivity (DTH) reaction, cellular immune response, IgG, IgE, IgM, cerebrospinal fluid biomarkers, hematological study, antioxidant profile, and lipid biomarkers. Chemical characterization of novel formulation showed retention time (R _t ) 18.98 of curcumin, while LC-MS data revealed the presence of the curcumin mass at m/z 369.01 [M + H]⁺ (calculated for C₂₁H₂₁O₆⁺, 369.13). This novel formulation exhibited significantly (p ≤ 0.001) increased primary and secondary antibody titer by 72.41% and 33.25%, respectively, while DTH response being improved by 87.50% (p ≤ 0.01). However, CD4⁺, CD8⁺, and CD28⁺ counts were significantly (p ≤ 0.05) increased by 76.46%, 68.21%, and 19.29%, respectively, while the concentrations of IgE, IgM, and IgG were significantly (p ≤ 0.05) increased by 40%, 28.43%, and 38.75%, respectively. CSF biomarkers analysis showed a decreased level of corticosterone, dopamine, serotonin, and tau protein by 29.38%, 51.73%, 29.93%, and 4.87%, respectively. Antioxidant enzymes such as CAT, GPx, and SOD were increased by 43.74%, 49.00%, and 40.84%, respectively, and non-enzymatic component, GSH, was increased by 55.52%. Similarly, free radical LPO was significantly (p ≤ 0.05) decreased by 40.37%, and acute inflammatory marker, MPO concentration, was reduced by 31.14%, compared with the disease control group. In addition, supportive hematology and lipid profile analysis showed promising results with improved overall animal profile. Thus, trace elements in novel formulation can be used in the various pharmacological activities and as dietary supplement due to its wide properties.

Curcumin protects against hepatic stellate cells activation and migration by inhibiting the CXCL12/CXCR4 biological axis in liver fibrosis：A study in vitro and in vivo

The C-X-C motif chemokine 12/C-X-C chemokine receptor type 4 (CXCL12/ CXCR4) biological axis plays an important role in the pathogenesis of liver fibrosis. Curcumin is known to have an anti-fibrosis effect, but the specific mechanism needs to be elucidated. There is currently no evidence illustrating a connection between curcumin and the CXCL12/CXCR4 axis in liver fibrosis. Here, we investigated the contribution of curcumin on CXCL12/ CXCR4 biological axis in liver fibrosis. Our results showed that curcumin remarkably improved hepatic function and liver fibrosis, and the effects are similar as silymarin. The alleviation of liver fibrosis with curcumin treatment was associated with a reduction of CXCL12, CXCR4, α-SMA and RhoA. In addition, curcumin markedly inhibited the proliferation and migration of HSC-T6 cells. This study indicates that curcumin could protect against hepatic stellate cells activation and migration by inhibiting the CXCL12/CXCR4 biological axis in liver fibrosis.

Enhanced Oral Bioavailability of Curcumin Using a Supersaturatable Self-Microemulsifying System Incorporating a Hydrophilic Polymer; In Vitro and In Vivo Investigations

A supersaturatable self-microemulsifying drug delivery system (S-SMEDDS) with a reduced amount of surfactant and incorporation of a polymer precipitation inhibitor, Eudragit® E PO was developed. The optimized S-SMEDDS formulation (SS-15) consisted of 55% surfactants, 40% oils, and 5% Eudragit® E PO (curcumin at 44.4 mg/g of the formulation). The precipitation profiles from the supersaturation assay revealed that the curcumin S-SMEDDS performed as a better inhibitor of curcumin precipitation in simulated gastric fluid over a 240-min study than the normal curcumin SMEDDS and an aqueous curcumin suspension. In addition, the mean droplet size of the curcumin S-SMEDDS (21.6 ± 0.1 nm) was significantly smaller than the SMEDDS (28.1 ± 0.3 nm). The curcumin S-SMEDDS exhibited a threefold reduction of Caco-2 cell toxicity when compared to the curcumin SMEDDS because of the reduced toxic effect of the surfactant present in the SMEDDS formulation. In addition, the absorptive permeability across the Caco-2 monolayer of curcumin in the S-SMEDDS was significantly higher than for the unformulated curcumin (~ 5-folds). The plasma concentration-time profiles from the oral absorption studies in rats dosed with the curcumin S-SMEDDS showed a 1.22- and 53.14-fold increased absorption of curcumin, compared to the SMEDDS and the aqueous suspension, respectively. The curcumin S-SMEDDS was stable under both intermediate and accelerated conditions after 6 months of storage.

Novel allylated monocarbonyl analogs of curcumin induce mitotic arrest and apoptosis by reactive oxygen species-mediated endoplasmic reticulum stress and inhibition of STAT3

Curcumin is a promising active compound from a natural source and is extensively being tested in clinical trials because of its bio-functional properties. However, poor bioavailability has hampered its clinical application. Numerous attempts have been made in our laboratory to discover analogs of curcumin with enhanced bioavailability and superior pharmacological activity. In this study, we have investigated a new series of allylated monocarbonyl analogs of curcumin (MAC) and tested their effect on gastric cancer cells. Our results show six MAC that selectively targeted cancer cell lines to inhibit growth and induce apoptosis. This activity was achieved by generation of reactive oxygen species (ROS) by MAC. We selected one effective MAC (CA10) for further investigation and show that CA10 inhibits cell growth by causing G2/M cell cycle arrest and induction of apoptotic death. CA10 induced ROS generation and subsequent activation of endoplasmic reticulum (ER) stress and inhibition of signal transducer and activator of transcription 3 (STAT3) phosphorylation, inhibits cancer cell proliferation. These anti-tumor activities of CA10 were confirmed in gastric cancer xenografts. CA10 induced ROS, activated the ER stress pathway and inhibited STAT3 phosphorylation and gastric xenografts tumor growth in mice. Our studies provide experimental evidence that MAC CA10 effectively targets gastric cancer in preclinical models by enhancing ROS and ROS-mediated signaling.

Toxicogenomic and bioinformatics platforms to identify key molecular mechanisms of a curcumin-analogue DM-1 toxicity in melanoma cells

Melanoma is a highly invasive and metastatic cancer with high mortality rates and chemoresistance. Around 50% of melanomas are driven by activating mutations in BRAF that has led to the development of potent anti-BRAF inhibitors. However resistance to anti-BRAF therapy usually develops within a few months and consequently there is a need to identify alternative therapies that will bypass BRAF inhibitor resistance. The curcumin analogue DM-1 (sodium 4-[5-(4-hydroxy-3-methoxy-phenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate) has substantial anti-tumor activity in melanoma, but its mechanism of action remains unclear. Here we use a synthetic lethal genetic screen in Saccharomyces cerevisiae to identify 211 genes implicated in sensitivity to DM-1 toxicity. From these 211 genes, 74 had close human orthologues implicated in oxidative phosphorylation, insulin signaling and iron and RNA metabolism. Further analysis identified 7 target genes (ADK, ATP6V0B, PEMT, TOP1, ZFP36, ZFP36L1, ZFP36L2) with differential expression during melanoma progression implicated in regulation of tumor progression, cell differentiation, and epithelial-mesenchymal transition. Of these TOP1 and ADK were regulated by DM-1 in treatment-naïve and vemurafenib-resistant melanoma cells respectively. These data reveal that the anticancer effect of curcumin analogues is likely to be mediated via multiple targets and identify several genes that represent candidates for combinatorial targeting in melanoma.

Curcumin mediates anticancer effects by modulating multiple cell signaling pathways

Curcumin, a component of a spice native to India, was first isolated in 1815 by Vogel and Pelletier from the rhizomes of Curcuma longa (turmeric) and, subsequently, the chemical structure of curcumin as diferuloylmethane was reported by Milobedzka et al. [(1910) 43., 2163-2170]. Since then, this polyphenol has been shown to exhibit antioxidant, anti-inflammatory, anticancer, antiviral, antibacterial, and antifungal activities. The current review primarily focuses on the anticancer potential of curcumin through the modulation of multiple cell signaling pathways. Curcumin modulates diverse transcription factors, inflammatory cytokines, enzymes, kinases, growth factors, receptors, and various other proteins with an affinity ranging from the pM to the mM range. Furthermore, curcumin effectively regulates tumor cell growth via modulation of numerous cell signaling pathways and potentiates the effect of chemotherapeutic agents and radiation against cancer. Curcumin can interact with most of the targets that are modulated by FDA-approved drugs for cancer therapy. The focus of this review is to discuss the molecular basis for the anticancer activities of curcumin based on preclinical and clinical findings.

Therapeutic effect of topical application of curcumin during treatment of radiation burns in a mini-pig model

Curcumin protects the skin against radiation-induced epidermal damage and prevents morphological changes induced by irradiation skin, thereby maintaining the epidermal thickness and cell density of basal layers. In this study, the effects of topical curcumin treatment on radiation burns were evaluated in a mini-pig model. Histological and clinical changes were observed five weeks after radiation exposure to the back (⁶⁰Co gamma-radiation, 50 Gy). Curcumin was applied topically to irradiated skin (200 mg/cm²) twice a day for 35 days. Curcumin application decreased the epithelial desquamation after irradiation. Additionally, when compared to the vehicle-treated group, the curcumin-treated group showed reduced expression of cyclooxygenase-2 and nuclear factor-kappaB. Furthermore, irradiation prolonged healing of biopsy wounds in the exposed area, whereas curcumin treatment stimulated wound healing. These results suggest that curcumin can improve epithelial cell survival and recovery in the skin and therefore be used to treat radiation burns.

A comprehensive approach to ascertain the binding mode of curcumin with DNA

Curcumin is a natural phytochemical from the rhizoma of Curcuma longa, the popular Indian spice that exhibits a wide range of pharmacological properties like antioxidant, anticancer, anti-inflammatory, antitumor, and antiviral activities. In the published literatures we can see different studies and arguments on the interaction of curcumin with DNA. The intercalative binding, groove binding and no binding of curcumin with DNA were reported. In this context, we conducted a detailed study to understand the mechanism of recognition of dimethylsulfoxide-solubilized curcumin by DNA. The interaction of curcumin with calf thymus DNA (ctDNA) was confirmed by agarose gel electrophoresis. The nature of binding and energetics of interaction were studied by Isothermal Titration Calorimetry (ITC), Differential Scanning Calorimetry (DSC), UV-visible, fluorescence and melting temperature (T_m) analysis. The experimental data were compared with molecular modeling studies. Our investigation confirmed that dimethylsulfoxide-solubilized curcumin binds in the minor groove of the ctDNA without causing significant structural alteration to the DNA.

Integrative Medicine in Head and Neck Cancer

Objective Complementary and alternative medicine, or integrative medicine, has become increasingly popular among patients with head and neck cancer. Despite its increasing prevalence, many patients feel uncomfortable discussing such therapies with their physicians, and many physicians are unaware and underequipped to evaluate or discuss their use with patients. The aim of this article is to use recent data to outline the decision making inherent to integrative medicine utilization among patients with head and neck cancer, to discuss the ethical implications inherent to balancing integrative and conventional approaches to treatment, and to highlight available resources to enhance head and neck cancer providers' understanding of integrative medicine. Data Sources Randomized controlled trials involving integrative medicine or complementary and alternative medicine treatment for cancer patients. Review Methods Trials were drawn from a systematic PubMed database search categorized into cancer prevention, treatment, and symptom management. Conclusions Integrative medicine is gaining popularity for the management of cancer and is most commonly used for symptom management. A number of randomized controlled trials provide data to support integrative therapies, yet physicians who treat head and neck cancer may be faced with ethical dilemmas and practical barriers surrounding incorporation of integrative medicine. Implications for Practice In the management of head and neck cancer, there is an increasing demand for awareness of, dialogue about, and research evaluating integrative medicine therapies. It is important for otolaryngologists to become aware of integrative therapy options, their risks and benefits, and resources for further information to effectively counsel their patients.

Anti-proliferative properties of commercial Pelargonium sidoides tincture, with cell-cycle G0/G1 arrest and apoptosis in Jurkat leukaemia cells

Context Pelargonium sidoides DC (Geraniaceae) is an important medicinal plant indigenous to South Africa and Lesotho. Previous studies have shown that root extracts are rich in polyphenolic compounds with antibacterial, antiviral and immunomodulatory activities. Little is known regarding the anticancer properties of Pelargonium sidoides extracts. Objective This study evaluates the anti-proliferative effects of a Pelargonium sidoides radix mother tincture (PST). Materials and methods The PST was characterized by LC-MS/MS. Anti-proliferative activity was evaluated in the pre-screen panel of the National Cancer Institute (NCI-H460, MCF-7 and SF-268) and the Jurkat leukaemia cell line at concentrations of 0-150 μg/mL. The effect on cell growth was determined with sulphorhodamine B and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays after 72 h. The effect on cell cycle and apoptosis induction in Jurkat cells was determined by flow cytometry with propidium iodide and Annexin V: fluorescein isothiocyanate staining. Results Dihydroxycoumarin sulphates, gallic acid as well as gallocatechin dimers and trimers were characterized in PST by mass spectrometry. Moderate anti-proliferative effects with GI50 values between 40 and 80 μg/mL were observed in the NCI-pre-screen panel. Strong activity observed with Jurkat cells with a GI50 value of 6.2 μg/mL, significantly better than positive control 5-fluorouracil (GI50 value of 9.7 μg/mL). The PST arrested Jurkat cells at the G0/G1 phase of the cell cycle and increased the apoptotic cells from 9% to 21%, while the dead cells increased from 4% to 17%. Conclusion We present evidence that P. sidoides has cancer cell type-specific anti-proliferative effects and may be a source of novel anticancer molecules.

The Role of Natural Polyphenols in the Prevention and Treatment of Cervical Cancer-An Overview

Cervical cancer represents the second leading cause of death for women worldwide. The importance of the diet and its impact on specific types of neoplasia has been highlighted, focusing again interest in the analysis of dietary phytochemicals. Polyphenols have shown a wide range of cellular effects: they may prevent carcinogens from reaching the targeted sites, support detoxification of reactive molecules, improve the elimination of transformed cells, increase the immune surveillance and the most important factor is that they can influence tumor suppressors and inhibit cellular proliferation, interfering in this way with the steps of carcinogenesis. From the studies reviewed in this paper, it is clear that certain dietary polyphenols hold great potential in the prevention and therapy of cervical cancer, because they interfere in carcinogenesis (in the initiation, development and progression) by modulating the critical processes of cellular proliferation, differentiation, apoptosis, angiogenesis and metastasis. Specifically, polyphenols inhibit the proliferation of HPV cells, through induction of apoptosis, growth arrest, inhibition of DNA synthesis and modulation of signal transduction pathways. The effects of combinations of polyphenols with chemotherapy and radiotherapy used in the treatment of cervical cancer showed results in the resistance of cervical tumor cells to chemo- and radiotherapy, one of the main problems in the treatment of cervical neoplasia that can lead to failure of the treatment because of the decreased efficiency of the therapy.

Vesicular (liposomal and nanoparticulated) delivery of curcumin: a comparative study on carbon tetrachloride-mediated oxidative hepatocellular damage in rat model

The liver plays a vital role in biotransforming and extricating xenobiotics and is thus prone to their toxicities. Short-term administration of carbon tetrachloride (CCl₄) causes hepatic inflammation by enhancing cellular reactive oxygen species (ROS) level, promoting mitochondrial dysfunction, and inducing cellular apoptosis. Curcumin is well accepted for its antioxidative and anti-inflammatory properties and can be considered as an effective therapeutic agent against hepatotoxicity. However, its therapeutic efficacy is compromised due to its insolubility in water. Vesicular delivery of curcumin can address this limitation and thereby enhance its effectiveness. In this study, it was observed that both liposomal and nanoparticulated formulations of curcumin could increase its efficacy significantly against hepatotoxicity by preventing cellular oxidative stress. However, the best protection could be obtained through the polymeric nanoparticle-mediated delivery of curcumin. Mitochondria have a pivotal role in ROS homeostasis and cell survivability. Along with the maintenance of cellular ROS levels, nanoparticulated curcumin also significantly (P<0.0001) increased cellular antioxidant enzymes, averted excessive mitochondrial destruction, and prevented total liver damage in CCl₄-treated rats. The therapy not only prevented cells from oxidative damage but also arrested the intrinsic apoptotic pathway. In addition, it also decreased the fatty changes in hepatocytes, centrizonal necrosis, and portal inflammation evident from the histopathological analysis. To conclude, curcumin-loaded polymeric nanoparticles are more effective in comparison to liposomal curcumin in preventing CCl₄-induced oxidative stress–mediated hepatocellular damage and thereby can be considered as an effective therapeutic strategy.

Stimulating the proliferation, migration and lamellipodia of Schwann cells using low-dose curcumin

Transplantation of peripheral glia is being trialled for neural repair therapies, and identification of compounds that enhance the activity of glia is therefore of therapeutic interest. We have previously shown that curcumin potently stimulates the activity of olfactory glia. We have now examined the effect of curcumin on Schwann cell (SC) activities including proliferation, migration and the expression of protein markers. SCs were treated with control media and with different concentrations of curcumin (0.02-20 μM). Cell proliferation was determined by MTS assay and migration changes were determined by single live cell migration tracking. We found that small doses of curcumin (40 nM) dramatically increased the proliferation and migration in SCs within just one day. When compared with olfactory glia, curcumin stimulated SC proliferation more rapidly and at lower concentrations. Curcumin significantly increased the migration of SCs, and also increased the dynamic activity of lamellipodial waves which are essential for SC migration. Expression of the activated form of the MAP kinase p38 (p-p38) was significantly decreased in curcumin-treated SCs. These results show that curcumin's effects on SCs differ remarkably to its effects on olfactory glia, suggesting that subtypes of closely related glia can be differentially stimulated by curcumin. Overall these results demonstrate that the therapeutically beneficial activities of glia can be differentially enhanced by curcumin which could be used to improve outcomes of neural repair therapies.

Filtering promiscuous compounds in early drug discovery: is it a good idea?

The use of computational filters for excluding supposedly nonspecific and promiscuous compounds from chemical libraries is a controversial issue, because many drugs used in clinics today would never reach the market if these filters were applied. In part, this conflict could be caused by the paradigm: one-drug-one-target, even though it is widely agreed that drug action is a result of a complex network of biomolecular interactions. Therefore, the so-called pan assay interference compounds (PAINS) or promiscuous compounds could be in fact assay artifacts, false positives or, simply, bright chemical matter (BCM) composed of privileged scaffolds, as we propose here. Despite apparent promiscuity, BCM can be tailored into new and safe drugs after overcoming selectivity criteria.

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.

A Curcumin Derivative That Inhibits Vinyl Carbamate-Induced Lung Carcinogenesis via Activation of the Nrf2 Protective Response

AIMS

Lung cancer has a high worldwide morbidity and mortality. The employment of chemopreventive agents is effective to reduce lung cancer. Nuclear factor erythroid 2-related factor 2 (Nrf2) mitigates insults from both exogenous and endogenous sources and thus has been verified as a target for chemoprevention. Curcumin has long been recognized as a chemopreventive agent, but poor bioavailability and weak Nrf2 induction have prohibited clinical application. Thus, we have developed new curcumin derivatives and tested their Nrf2 induction.

RESULTS

Based on curcumin, we synthesized curcumin analogs with five carbon linkages and established a structure-activity relationship for Nrf2 induction. Among these derivatives, bis[2-hydroxybenzylidene]acetone (BHBA) was one of the most potent Nrf2 inducers with minimal toxicity and improved pharmacological properties and was thus selected for further investigation. BHBA activated the Nrf2 pathway in the canonical Keap1-Cys151-dependent manner. Furthermore, BHBA was able to protect human lung epithelial cells against sodium arsenite [As(III)]-induced cytotoxicity. More importantly, in an in vivo vinyl carbamate-induced lung cancer model in A/J mice, preadministration of BHBA significantly reduced lung adenocarcinoma, while curcumin failed to show any effects even at high doses.

INNOVATION

The curcumin derivative, BHBA, is a potent inducer of Nrf2. It was demonstrated to protect against As(III) toxicity in lung epithelial cells in an Nrf2-dependent manner. Furthermore, compared with curcumin, BHBA displayed improved chemopreventive activities in a carcinogen-induced lung cancer model.

CONCLUSION

Taken together, our results demonstrate that BHBA, a curcumin analog with improved Nrf2-activating and chemopreventive activities both in vitro and in vivo, could be developed into a chemoprotective pharmacological agent.

Hexamethoxylated Monocarbonyl Analogues of Curcumin Cause G2/M Cell Cycle Arrest in NCI-H460 Cells via Michael Acceptor-Dependent Redox Intervention

Curcumin, derived from the dietary spice turmeric, holds promise for cancer prevention. This prompts much interest in investigating the action mechanisms of curcumin and its analogues. Two symmetrical hexamethoxy-diarylpentadienones (1 and 2) as cucumin analogues were reported to possess significantly enhanced cytotoxicity compared with the parent molecule. However, the detailed mechanisms remain unclear. In this study, compounds 1 and 2 were identified as the G2/M cell cycle arrest agents to mediate the cytotoxicity toward NCI-H460 cells via Michael acceptor-dependent redox intervention. Compared with curcumin, they could more easily induce a burst of reactive oxygen species (ROS) and collapse of the redox buffering system. One possible reason is that they could more effectively target intracellular TrxR to convert this antioxidant enzyme into a ROS promoter. Additionally, they caused up-regulation of p53 and p21 and down-regulation of redox-sensitive Cdc25C along with cyclin B1/Cdk1 in a Michael acceptor- and ROS-dependent fashion. Interestingly, in comparison with compound 2, compound 1 displayed a relatively weak ability to generate ROS but increased cell cycle arrest activity and cytotoxicity probably due to its Michael acceptor-dependent microtubule-destabilizing effect and greater GST-inhibitory activity, as well as its enhanced cellular uptake. This work provides useful information for understanding Michael acceptor-dependent and redox-mediated cytotoxic mechanisms of curcumin and its active analogues.

Curcumin raises lipid content by Wnt pathway in hepatic stellate cell

BACKGROUND

Activation of hepatic stellate cells (HSCs) is a pivotal event in liver fibrosis, which is characterized by dramatic disappearance of lipid droplets. However, the underlying molecular mechanisms are largely unknown. We aimed to explore the role of Wnt/β-catenin pathway in HSC lipogenesis and to examine the effects of curcumin in this molecular context.

METHODS

Primary rat HSCs were cultured in vitro for experiments. The Wnt activator WAY-262611 and β-catenin activator lithium chloride (LiCl) were used to activate the pathway at distinct levels in HSCs. Cell proliferation, fibrogenic markers, intracellular lipids and triglyceride, and adipogenic transcription factors were examined in HSCs.

RESULTS

Both WAY-262611 and LiCl promoted proliferation and upregulated the expression of α-smooth muscle actin and α1(I) procollagen, but they decreased the contents of intracellular lipids and triglyceride in HSCs. Analyses of adipogenic transcription pattern showed that the two compounds reduced the expression of peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein α, retinoid X receptor-α, and retinoic acid receptor-β, four key transcription regulators of HSC adipogenic phenotype. Curcumin also reduced the expression of Frizzled and β-catenin, upregulated the expression of adipogenic transcription factors, and restored lipid content in HSCs. However, both WAY-262611 and LiCl abrogated curcumin restoration of lipogenesis and inhibition of fibrogenic marker expression in HSCs.

CONCLUSIONS

Wnt/β-catenin pathway was a profibrogenic signaling and inhibited lipogenesis by suppressing adipogenic transcription pattern in HSCs. Blockade of this pathway was associated with curcumin stimulation of HSC lipogenesis. We revealed a novel mechanism underlying curcumin restoration of lipid droplets during HSC activation.

Functional and therapeutic significance of protein kinase D enzymes in invasive breast cancer

The protein kinase D (PKD) family members, PKD1, PKD2 and PKD3 constitute a family of serine/threonine kinases that are essential regulators of cell migration, proliferation and protein transport. Multiple types of cancers are characterized by aberrant expression of PKD isoforms. In breast cancer PKD isoforms exhibit distinct expression patterns and regulate various oncogenic processes. In highly invasive breast cancer, the leading cause of cancer-associated deaths in females, the loss of PKD1 is thought to promote invasion and metastasis, while PKD2 and upregulated PKD3 have been shown to be positive regulators of proliferation, chemoresistance and metastasis. In this review, we examine the differential expression pattern, mechanisms of regulation and contributions made by each PKD isoform to the development and maintenance of invasive breast cancer. In addition, we discuss the potential therapeutic approaches for targeting PKD in this disease.

Inhibition of lung cancer cells A549 and H460 by curcuminoid extracts and nanoemulsions prepared from Curcuma longa Linnaeus

The objectives of this study were to explore the inhibition mechanism of lung cancer cells A549 and H460 by curcuminoid extracts and nanoemulsions prepared from Curcuma longa Linnaeus. In addition, human bronchus epithelial cell line BEAS-2B (normal cell) was selected for comparison. A high-performance liquid chromatography (HPLC) method was developed to separate and quantify the various curcuminoids in C. longa extract, including curcumin (1,714.5 μg/mL), demethoxycurcumin (1,147.4 μg/mL), and bisdemethoxycurcumin (190.2 μg/mL). A high-stability nanoemulsion composed of Tween 80, water, and curcuminoid extract was prepared, with mean particle size being 12.6 nm. The cell cycle was retarded at G2/M for both the curcuminoid extract and nanoemulsion treatments; however, the inhibition pathway may be different. H460 cells were more susceptible to apoptosis than A549 cells for both curcuminoid extract and nanoemulsion treatments. Growth of BEAS-2B remained unaffected for both the curcuminoid extract and nanoemulsion treatments, with a concentration range from 1 to 4 μg/mL. Also, the activities of caspase-3, caspase-8, and caspase-9 followed a dose-dependent increase for both A549 and H460 cells for both the treatments, accompanied by a dose-dependent increase in cytochrome C expression and a dose-dependent decrease in CDK1 expression. Interestingly, a dose-dependent increase in cyclin B expression was shown for A549 cells for both the treatments, while a reversed trend was found for H460 cells. Both mitochondria and death receptor pathways may be responsible for apoptosis of both A549 and H460 cells.

Ameliorative Effects of Curcumin on Artesunate-Induced Subchronic Toxicity in Testis of Swiss Albino Male Mice

India is one of the endemic areas where control of malaria has become a formidable task. Artesunate is the current antimalarial drug used to treat malaria, especially chloroquine resistant. The objective of the present study was to investigate the dose-dependent effect of oral administration of artesunate on the oxidative parameters in testes of adult male Swiss albino mice and ameliorative efficacy of curcumin, a widely used antioxidant. An oral dose of 150 mg/kg body weight (bwt; low dose) and 300 mg/kg bwt (high dose) of artesunate was administered for a period of 45 days to male mice, and ameliorative efficacy of curcumin was also assessed. The results revealed that artesunate caused significant alteration in oxidative parameters in dose-dependent manner. Administration of artesunate brought about significant decrease in activities of superoxide dismutase, glutathione, glutathione peroxidase, and glutathione reductase, whereas lipid peroxidation and glutathione-S-transferase activity were found to be significantly increased. The results obtained show that oxidative insult is incurred upon the intracellular antioxidant system of testis tissue by artesunate treatment. Further, administration of curcumin at the dose level of 80 mg/kg bwt along with both doses of artesunate attenuated adverse effects in male mice.

Curcumin ameliorates the tumor-enhancing effects of a high-protein diet in an azoxymethane-induced mouse model of colon carcinogenesis

An increasing number of reports suggest that a high-protein diet (HPD) is associated with an increased risk for colorectal cancer (CRC). One of the proposed mechanisms is that an HPD increases the delivery of protein to the colon and generates various toxic metabolites that contribute to colon carcinogenesis. Curcumin was shown to exert significant preventive properties against CRC. We therefore hypothesized that curcumin can reverse the tumor-enhancing effects of an HPD. This study examined the effects of curcumin on the development of azoxymethane (AOM)-induced colorectal tumors in HPD-fed mice. A total of 30 female Balb/c mice were randomly divided into 3 groups: those fed a normal diet (20% casein), those fed an HPD (HPD; 50% casein), and those fed an HPD supplemented with curcumin (HPDC; 0.02% curcumin). The mice were subjected to an AOM-dextran sodium sulfate colon carcinogenesis protocol. Mice in the HPDC group exhibited a significant (40%) reduction in colorectal tumor multiplicity when compared with those in the HPD group. The expression of colonic inflammatory proteins (cyclooxygenase-2 and inducible nitric oxide synthase), the levels of plasma inflammatory markers (nitric oxide and tumor necrosis factor-α), fecal ammonia, short- and branched-chain fatty acid levels, and the rate of colonocyte proliferation were significantly lower in the HPDC than the HPD group. In conclusion, curcumin inhibited the development of colorectal tumors in an AOM-induced mouse model of colon carcinogenesis by attenuating colonic inflammation, proliferation, and toxic metabolite production. Curcumin might be useful in the chemoprevention of CRC in individuals consuming an HPD.

Inhibition of IL-6 signaling pathway by curcumin in uterine decidual cells

IL-6 is a multifunctional pro-inflammatory cytokine and has been implicated in many gestational disorders including preterm birth. Currently, there are no appropriate therapeutic interventions available to circumvent inflammatory-mediated gestational disorders. Therefore, the goal of this study was to identify a safe and effective pharmacological compound to counterbalance inflammatory responses in the uterus. Curcumin, a naturally-occuring polyphenolic compound, has been widely used in alternative medicine to treat inflammatory diseases. However, the anti-inflammatory effect of curcumin has not been explored in uterine decidual cells, a major source of IL-6. Therefore, we examined the effect of curcumin on IL-6 expression using two types of uterine decidual cells 1) HuF cells, primary human fibroblast cells obtained from the decidua parietalis; 2) UIII cells, a rodent non-transformed decidual cell line. Curcumin treatment completely abrogated the expression of IL-1β-induced IL-6 in these cells. Curcumin also strongly inhibited the expression of gp130, a critical molecule in IL-6 signaling, whereas expression of IL-6R and sIL-6R was not affected. Curcumin also inhibited phosphorylation and nuclear localization of STAT3, a well-known downstream mediator of IL-6 signaling. Furthermore, curcumin attenuated IL-1β-induced IL-6 promoter reporter activity suggesting transcriptional regulation. To further understand whether NF-ҡB is involved in this inhibition, we examined the effect of curcumin on the expression of p50 and p65 subunits of NF-ҡB in decidual cells. Expression of IL-1β-induced p50 mRNA was repressed by curcumin while p65 mRNA was not affected. However, curcumin treatment dramatically inhibited both p50 and p65 protein levels and prevented its nuclear localization. This effect is at least partly mediated through the deactivation of IKK, since IL-1β-induced IKKα/β phosphorylation is decreased upon curcumin treatment. Our results not only revealed molecular mechanisms underlying curcumin action in uterine decidual cells but also suggest that this compound may have therapeutic potential for the prevention of inflammation-mediated preterm birth and other gestational disorders.

Curcumin as a putative antidepressant

Due to inadequate efficacy of antidepressants, various new chemical entities and agents of natural origin have been tested for therapeutic efficacy both alone and to augment existing antidepressants, producing varied clinical results. This article summarizes the basic properties of curcumin and its mechanisms of action, with specific emphasis on the etiopathogenesis of depression, preclinical and current clinical evidence, and future research directions, to better understand the possible role of curcumin in treating depression. Curcumin may have antidepressant activities with diverse mechanisms of action involving primarily neurotransmitters, transcription pathways, neurogenesis, the hypothalamic-pituitary-adrenal axis and inflammatory and immune pathways, as demonstrated in various animal and human studies. Current published randomized clinical trials suggest a small, non-significant benefit of curcumin for major depression. More adequately-powered and methodologically improved studies are mandatory.

Continuous flow vortex fluidic synthesis of silica xerogel as a delivery vehicle for curcumin

Sol–gel synthesis of silica xerogel using a continuous flow vortex fluidic device at room temperature is effective in direct incorporation of preformed curcumin particles, which has antimicrobial activity against Staphylococcus aureus.

Computer evaluation of hidden potential of phytochemicals of medicinal plants of the traditional indian ayurvedic medicine

Applicability of our computer programs PASS and PharmaExpert to prediction of biological activity spectra of rather complex and structurally diverse phytocomponents of medicinal plants, both separately and in combinations has been evaluated. The web-resource on phytochemicals of 50 medicinal plants used in Ayurveda was created for the study of hidden therapeutic potential of Traditional Indian Medicine (TIM) (http://ayurveda.pharmaexpert.ru). It contains information on 50 medicinal plants, their using in TIM and their pharmacology activities, also as 1906 phytocomponents. PASS training set was updated by addition of information about 946 natural compounds; then the training procedure and validation were performed, to estimate the quality of PASS prediction. It was shown that the difference between the average accuracy of prediction obtained in leave-5%-out cross-validation (94,467%) and in leave-one-out cross-validation (94,605%) is very small. These results showed high predictive ability of the program. Results of biological activity spectra prediction for all phytocomponents included in our database are in good correspondence with the experimental data. Additional kinds of biological activity predicted with high probability provide the information about most promising directions of further studies. The analysis of prediction results of sets of phytocomponents in each of 50 medicinal plants was made by PharmaExpert software. Based on this analysis, we found that the combination of phytocomponents from Passiflora incarnata may exhibit nootropic, anticonvulsant and antidepressant effects. Experiments carried out in mice models confirmed the predicted effects of Passiflora incarnata extracts.

Curcumin differs from tetrahydrocurcumin for molecular targets, signaling pathways and cellular responses

Curcumin (diferuloylmethane), a golden pigment from turmeric, has been linked with antioxidant, anti-inflammatory, anticancer, antiviral, antibacterial, and antidiabetic properties. Most of the these activities have been assigned to methoxy, hydroxyl, α,β-unsaturated carbonyl moiety or to diketone groups present in curcumin. One of the major metabolites of curcumin is tetrahydrocurcumin (THC), which lacks α,β-unsaturated carbonyl moiety and is white in color. Whether THC is superior to curcumin on a molecular level is unclear and thus is the focus of this review. Various studies suggest that curcumin is a more potent antioxidant than THC; curcumin (but not THC) can bind and inhibit numerous targets including DNA (cytosine-5)-methyltransferase-1, heme oxygenase-1, Nrf2, β-catenin, cyclooxygenase-2, NF-kappaB, inducible nitric oxide synthase, nitric oxide, amyloid plaques, reactive oxygen species, vascular endothelial growth factor, cyclin D1, glutathione, P300/CBP, 5-lipoxygenase, cytosolic phospholipase A2, prostaglandin E2, inhibitor of NF-kappaB kinase-1, -2, P38MAPK, p-Tau, tumor necrosis factor-α, forkhead box O3a, CRAC; curcumin can inhibit tumor cell growth and suppress cellular entry of viruses such as influenza A virus and hepatitis C virus much more effectively than THC; curcumin affects membrane mobility; and curcumin is also more effective than THC in suppressing phorbol-ester-induced tumor promotion. Other studies, however, suggest that THC is superior to curcumin for induction of GSH peroxidase, glutathione-S-transferase, NADPH: quinone reductase, and quenching of free radicals. Most studies have indicated that THC exhibits higher antioxidant activity, but curcumin exhibits both pro-oxidant and antioxidant properties.

Tumour suppressor HLJ1: A potential diagnostic, preventive and therapeutic target in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related mortality throughout the world. Non-small cell lung cancer (NSCLC) accounts for 85% of all diagnosed lung cancers. Despite considerable progress in the diagnosis and treatment of the disease, the overall 5-year survival rate of NSCLC patients remains lower than 15%. The most common causes of death in lung cancer patients are treatment failure and metastasis. Therefore, developing novel strategies that target both tumour growth and metastasis is an important and urgent mission for the next generation of anticancer therapy research. Heat shock proteins (HSPs), which are involved in the fundamental defence mechanism for maintaining cellular viability, are markedly activated during environmental or pathogenic stress. HSPs facilitate rapid cell division, metastasis, and the evasion of apoptosis in cancer development. These proteins are essential players in the development of cancer and are prime therapeutic targets. In this review, we focus on the current understanding of the molecular mechanisms responsible for HLJ1’s role in lung cancer carcinogenesis and progression. HLJ1, a member of the human HSP 40 family, has been characterised as a tumour suppressor. Research studies have also reported that HLJ1 shows promising dual anticancer effects, inhibiting both tumour growth and metastasis in NSCLC. The accumulated evidence suggests that HLJ1 is a potential biomarker and treatment target for NSCLC.

Turmeric toxicity in A431 epidermoid cancer cells associates with autophagy degradation of anti-apoptotic and anti-autophagic p53 mutant

The keratinocyte-derived A431 Squamous Cell Carcinoma cells express the p53R273H mutant, which has been reported to inhibit apoptosis and autophagy. Here, we show that the crude extract of turmeric (Curcuma longa), similarly to its bioactive component Curcumin, could induce both apoptosis and autophagy in A431 cells, and these effects were concomitant with degradation of p53. Turmeric and curcumin also stimulated the activity of mTOR, which notoriously promotes cell growth and acts negatively on basal autophagy. Rapamycin-mediated inhibition of mTOR synergized with turmeric and curcumin in causing p53 degradation, increased the production of autophagosomes and exacerbated cell toxicity leading to cell necrosis. Small-interference mediated silencing of the autophagy proteins BECLIN 1 or ATG7 abrogated the induction of autophagy and largely rescued p53 stability in Turmeric-treated or Curcumin-treated cells, indicating that macroautophagy was mainly responsible for mutant p53 degradation. These data uncover a novel mechanism of turmeric and curcumin toxicity in chemoresistant cancer cells bearing mutant p53.

Low-dose curcumin stimulates proliferation, migration and phagocytic activity of olfactory ensheathing cells

One of the promising strategies for neural repair therapies is the transplantation of olfactory ensheathing cells (OECs) which are the glial cells of the olfactory system. We evaluated the effects of curcumin on the behaviour of mouse OECs to determine if it could be of use to further enhance the therapeutic potential of OECs. Curcumin, a natural polyphenol compound found in the spice turmeric, is known for its anti-cancer properties at doses over 10 µM, and often at 50 µM, and it exerts its effects on cancer cells in part by activation of MAP kinases. In contrast, we found that low-dose curcumin (0.5 µM) applied to OECs strikingly modulated the dynamic morphology, increased the rate of migration by up to 4-fold, and promoted significant proliferation of the OECs. Most dramatically, low-dose curcumin stimulated a 10-fold increase in the phagocytic activity of OECs. All of these potently stimulated behavioural characteristics of OECs are favourable for neural repair therapies. Importantly, low-dose curcumin gave a transient activation of p38 kinases, which is in contrast to the high dose curcumin effects on cancer cells in which these MAP kinases tend to undergo prolonged activation. Low-dose curcumin mediated effects on OECs demonstrate cell-type specific stimulation of p38 and ERK kinases. These results constitute the first evidence that low-dose curcumin can modulate the behaviour of olfactory glia into a phenotype potentially more favourable for neural repair and thereby improve the therapeutic use of OECs for neural repair therapies.

Polyphenols and the modulation of gene expression pathways: can we eat our way out of the danger of chronic disease?

Plant-derived dietary polyphenols may improve some disease states and promote health. Experimental evidence suggests that this is partially attributable to changes in gene expression. The rational use of bioactive food components may therefore present an opportunity to activate or repress selected gene expression pathways and, consequently, to manage or prevent disease. It remains to be determined whether this use of bioactive food components can be done safely. This article reviews the associated controversies and limitations of polyphenol therapy. There is a paucity of clinical data on the rational use of polyphenols, including a lack of knowledge on effective dosage, actual chemical formulations, bioavailability, distribution in tissues, the effect of genetic variations, differences in gut microflora, the synergistic (or antagonistic) effects observed in extracts, and the possible interaction between polyphenols and lipid domains of cell membranes that may alter the function of relevant receptors. The seminal question of why plants make substances that benefit humans remains unanswered, and there is still much to learn in terms of correlative versus causal effects of human exposure to various nutrients. The available data strongly suggest significant effects at the molecular level that represent interactions with the epigenome. The advent of relatively simple technologies is helping the field of epigenetics progress and facilitating the acquisition of multiple types of data that were previously difficult to obtain. In this review, we summarize the molecular basis of the epigenetic regulation of gene expression and the epigenetic changes associated with the consumption of polyphenols that illustrate how modifications in human nutrition may become relevant to health and disease.

Decrease of a specific biomarker of collagen degradation in osteoarthritis, Coll2-1, by treatment with highly bioavailable curcumin during an exploratory clinical trial

Background

The management of osteoarthritis (OA) remains a challenge. There is a need not only for safe and efficient treatments but also for accurate and reliable biomarkers that would help diagnosis and monitoring both disease activity and treatment efficacy. Curcumin is basically a spice that is known for its anti-inflammatory properties. In vitro studies suggest that curcumin could be beneficial for cartilage in OA. The aim of this exploratory, non-controlled clinical trial was to evaluate the effects of bio-optimized curcumin in knee OA patients on the serum levels of specific biomarkers of OA and on the evaluation of pain.

Methods

Twenty two patients with knee OA were asked to take 2x3 caps/day of bio-optimized curcumin (Flexofytol®) for 3 months. They were monitored after 7, 14, 28 and 84 days of treatment. Pain over the last 24 hours and global assessment of disease activity by the patient were evaluated using a visual analog scale (100 mm). The serum levels of Coll-2-1, Coll-2-1NO₂, Fib3-1, Fib3-2, CRP, CTX-II and MPO were determined before and after 14 and 84 days of treatment.

Results

The treatment with curcumin was globally well tolerated. It significantly reduced the serum level of Coll2-1 (p < 0.002) and tended to decrease CRP. No other significant difference was observed with the other biomarkers. In addition, curcumin significantly reduced the global assessment of disease activity by the patient.

Conclusion

This study highlighted the potential effect of curcumin in knee OA patient. This effect was reflected by the variation of a cartilage specific biomarker, Coll2-1 that was rapidly affected by the treatment. These results are encouraging for the qualification of Coll2-1 as a biomarker for the evaluation of curcumin in OA treatment.

Trial registration

NCT01909037 at clinicaltrials.gov

Efficacy and safety of curcumin in major depressive disorder: a randomized controlled trial

Curcumin, an active ingredient of Curcuma longa Linn (Zingiberaceae), has shown potential antidepressant-like activity in animal studies. The objectives of this trial were to compare the efficacy and safety of curcumin with fluoxetine in patients with major depressive disorder (MDD). Herein, 60 patients diagnosed with MDD were randomized in a 1:1:1 ratio for six weeks observer-masked treatment with fluoxetine (20 mg) and curcumin (1000 mg) individually or their combination. The primary efficacy variable was response rates according to Hamilton Depression Rating Scale, 17-item version (HAM-D17 ). The secondary efficacy variable was the mean change in HAM-D17 score after six weeks. We observed that curcumin was well tolerated by all the patients. The proportion of responders as measured by the HAM-D17 scale was higher in the combination group (77.8%) than in the fluoxetine (64.7%) and the curcumin (62.5%) groups; however, these data were not statistically significant (P = 0.58). Interestingly, the mean change in HAM-D17 score at the end of six weeks was comparable in all three groups (P = 0.77). This study provides first clinical evidence that curcumin may be used as an effective and safe modality for treatment in patients with MDD without concurrent suicidal ideation or other psychotic disorders. .