Dosage effects of curcumin on cell death types in a human osteoblast cell line

Synthesis of Ethylphosphonate Curcumin Mimics: Substituents Allow Switching Between Cytotoxic and Cytoprotective Activities

Curcumin is recognized for its diverse biological activities, including the ability to induce apoptosis and ferroptosis. Therefore, it represents a promising candidate for the development of new compounds with neuroprotective and anticancer properties. In order to synthesize mimics with improved pharmacokinetic properties (better solubility and stability than curcumin) here, we present the design and synthesis of novel curcumin analogues named Ethylphosphonate-based curcumin mimics (EPs), which preserve the pharmacophoric features of curcumin. New EP mimics were synthesized by tyrosol- and melatonin-based building blocks using an orthogonal protection approach of the different precursors' OH functions with good yields and in a few steps. Comparative screenings of the cytotoxic and cytoprotective properties (curcumin was used as a reference compound) were carried out on all new mimics in different cell lines (HeLa, A375, WM266, MDA-MB-231, LX2, and HDF). Assays with inhibitors of ferroptosis (Ferrostatin-1, Fer-1) and apoptosis (Quinoline-Val-Asp-difluorophenoxymethyl ketone, Q-VD), in combination with curcumin, suggested the specific cell death pathway (apoptotic or ferroptotic) of EPs, depending on the aromatic moieties contained in them. Interestingly, EP4 exhibited substantial cytotoxic effects against various human cancer cell lines (HeLa, A375, WM266) while sparing normal cells (HDFs). EP4 displayed a five-times-higher toxicity in triple-negative MDA-MB-231 and LX2 stellate cells than curcumin. The cytotoxicity exerted by EP4 involves only an apoptotic mechanism, contrary to curcumin, which exerts both apoptotic and ferroptotic effects. Additionally, EP4 was also found to be a very potent inhibitor of the ubiquitin-activating enzyme E1, reinforcing the anticancer potential of this compound. Furthermore, EP2 possesses high antioxidant properties, efficiently protects against cell death by ferroptosis, and inhibits the amyloid aggregation involved in AD.

Cellulose nanofiber reinforced curcumin-infused calcium phosphate silicate cement for various bone-tissue engineering application

Introduction

This study utilized a injectable curcumin (Cur)-infused calcium phosphate silicate cement (CPSC) for addressing defects caused by bone cancer, and evaluated its promoting bone regeneration and exerting cytotoxic effects on osteosarcoma cells.

Methods

The material's physicochemical properties, biocompatibility with osteoblasts, and cytotoxicity toward osteosarcoma cells were rigorously analyzed.

Results

The findings demonstrate that CPSC-Cur signicantly prolongs the setting time, which can be optimized by adding silanized cellulose nanober (CNF-SH) to achieve a balance between workability and mechanical strength. Biological assessments reveal a pronounced cytotoxic effect on osteosarcoma cells while maintaining minimal toxicity toward pre-osteoblasts, highlighting CPSC-Cur's potential as a promising material for repairing bone defects following cancer removal.

Conclusion

This study lays the groundwork for future investigations into CPSC-Cur's in vivo efficacy and its role in the clinical treatment of bone cancer.

Dose-dependent effects of silver nanoparticles on cell death modes in mouse blastocysts induced via endoplasmic reticulum stress and mitochondrial apoptosis

In view of the rapidly expanding medical and commercial applications of silver nanoparticles (AgNPs), their potential health risks and environmental effects are a significant growing concern. Earlier research by our group uncovered the embryotoxic potential of AgNPs, showing detrimental impacts of these nanoparticles on both pre- and post-implantation embryonic development. In the current study, we showed that low (50-100 μM) and high (200-400 μM) dose ranges of AgNPs trigger distinct cell death programs affecting mouse embryo development and further explored the underlying mechanisms. Treatment with low concentrations of AgNPs (50-100 μM) triggered ROS generation, in turn, inducing mitochondria-dependent apoptosis, and ultimately, harmful effects on embryo implantation, post-implantation development, and fetal development. Notably, high concentrations of AgNPs (200-400 μM) evoked more high-level ROS generation and endoplasmic reticulum (ER) stress-mediated necrosis. Interestingly, pre-incubation with Trolox, a strong antioxidant, reduced ROS generation in the group treated with 200-400 μM AgNPs to the level induced by 50-100 μM AgNPs, resulting in switching of the cell death mode from necrosis to apoptosis and a significant improvement in the impairment of embryonic development. Our findings additionally indicate that activation of PAK2 is a crucial step in AgNP-triggered apoptosis and sequent detrimental effects on embryonic development. Based on the collective results, we propose that the levels of ROS generated by AgNP treatment of embryos serve as a critical regulator of cell death type, leading to differential degrees of damage to embryo implantation, post-implantation development and fetal development through triggering apoptosis, necrosis or other cell death signaling cascades.

Curcumin-loaded scaffolds in bone regeneration

In recent years, there has been a notable surge in the development of engineered bone scaffolds intended for the repair of bone defects. While autografts and allografts have traditionally served as the primary methods in bone tissue engineering, their inherent limitations have spurred the exploration of novel avenues in biomedical implant development. The emergence of bone scaffolds not only facilitates bone reconstruction but also offers a platform for the targeted delivery of therapeutic agents. There exists a pervasive interest in leveraging various drugs, proteins, growth factors, and biomolecules with osteogenic properties to augment bone formation, as the enduring side effects associated with current clinical modalities necessitate the pursuit of safer alternatives. Curcumin, the principal bioactive compound found in turmeric, has demonstrated notable efficacy in regulating the proliferation and differentiation of bone cells while promoting bone formation. Nevertheless, its utility is hindered by restricted water solubility and poor bioavailability. Strategies aimed at enhancing the solubility, stability, and bioavailability of curcumin, including formulation techniques such as liposomes and nanoparticles or its complexation with metals, have been explored. This investigation is dedicated to exploring the impact of curcumin on the proliferation, differentiation, and migration of osteocytes, osteoblasts, and osteoclasts.

A New Biomaterial Derived from Aloe vera-Acemannan from Basic Studies to Clinical Application

Aloe vera is a kind of herb rich in polysaccharides. Acemannan (AC) is considered to be a natural polysaccharide with good biodegradability and biocompatibility extracted from Aloe vera and has a wide range of applications in the biomedical field due to excellent immunomodulatory, antiviral, antitumor, and tissue regeneration effects. In recent years, clinical case reports on the application of AC as a novel biomedical material in tissue regenerative medicine have emerged; it is mainly used in bone tissue engineering, pulp-dentin complex regeneration engineering, and soft tissue repair, among other operations. In addition, multiple studies have proved that the new composite products formed by the combination of AC and other compounds have excellent biological and physical properties and have broader research prospects. This paper introduces the preparation process, surface structure, and application forms of AC; summarizes the influence of acetyl functional group content in AC on its functions; and provides a detailed review of the functional properties, laboratory studies, clinical cutting-edge applications, and combined applications of AC. Finally, the current application status of AC from basic research to clinical treatment is analyzed and its prospects are discussed.

Investigation and multiscale modeling of PVA/SA coated poly lactic acid scaffold containing curcumin loaded layered double hydroxide nanohybrids

Applying hydrophilic coatings on polymeric nanofibers combined with layered double hydroxide (LDH) not only enhances the efficiency of drug delivery systems but also increases cell adhesion. This work aimed to prepare poly(vinyl alcohol)/sodium alginate (PVA/SA) (2/1)-coated poly(lactic acid) (PLA) nanofibers containing curcumin-loaded layered double hydroxide (LDH) and to investigate their drug release and mechanical properties and their biocompatibility. The optimum PLA nanofibrous sample was considered to be that based on 3 wt% of curcumin-loaded LDH (PLA-3%LDH) with a drug encapsulation efficiency of ∼18% in which a minimum average nanofiber diameter of ∼476 nm along with a high tensile strength of 3.00 MPa were obtained. In the next step, a PVA/SA (2/1) layer was coated on the PLA-3%LDH; as a result, the hydrophilicity of the sample was improved and the elongation at break was decreased remarkably. In this regard the cell viability reached 80% for the coated PLA. Moreover, the formation of a layer of (PVA/SA) on the PLA nanofibers lowered the burst release and resulted in a more sustained drug release, which is a vital feature in dermal applications. A multiscale modeling method was applied for simulation of the mechanical properties of the composite scaffold and the results showed that this method can predict the data with 83% accuracy. The results of this study indicate that the formation of a layer of PVA/SA (2/1) has a significant effect on hydrophilicity and consequently improves cell adhesion and proliferation.

Effects of Curcumin and Lactoferrin to Inhibit the Growth and Migration of Prostatic Cancer Cells

Prostate cancer remains one of the main causes of death for men worldwide. Despite recent advances in cancer treatment, patients develop resistance after an initial period of optimal efficacy. Nowadays, it is accepted that natural compounds can result in health benefits with a preventive or adjuvant effect. The purpose of this study was to evaluate the effects of curcumin (CU), a bioactive compound in the spice turmeric, and lactoferrin (LF), a natural glycoprotein with immunomodulatory properties, on DU145 and PC3. Prostate cancer cells were cultured with and without LF (175 μM) and CU (2.5 μg/mL and 5 μg/mL), alone and in combination. Cell viability, migration ability, death receptors (DRs), and integrins (α3, β1) gene expression were evaluated, as well as human annexin V quantification and Akt phosphorylation. Differences among cells group, defined according to the treatment used, were assessed with ANOVA. The results showed that the effects of CU and LF are different between the two prostatic cell lines analyzed. In DU145, a reduction in cell proliferation and migration is reported both in the presence of single and combined treatments. In PC3 cells, there is a significant reduction in proliferation in the presence of CU alone, while the inhibition of migration is mainly related to the LF treatment and its combination with CU, compared to untreated cells. Moreover, the reduction in gene expression of integrins and Akt pathway activation were observed mostly in the presence of the CU and LF combination, including the upregulation of DR and annexin V levels, with greater significance for the DU145 cells. In conclusion, our results suggest that CU and LF may have a potentially beneficial effect, mainly when administered in combination, leading to a reduction in cancer cells' aggressiveness.

Transition metallo-curcumin complexes: a new hope for endometriosis?

Endometriosis is a debilitating gynecological disorder in women of reproductive age. Laparoscopy, a minimally invasive surgical procedure, provides a definitive diagnosis of the disease. Current treatments, including hormonal therapy and pain medication, are often associated with undesirable side effects limiting their long-term usage. This calls for exploring newer diagnostic and therapeutic options with minimal side effects. Curcumin is an established anti-endometriotic agent with inherent fluorescent properties; however, poor bioavailability limits its clinical utility. To address this shortcoming, various transition metals were conjugated with curcumin to improve its stability, specificity and pharmacological properties. The chemical stability, hemocompatibility and ability of the synthesized metallo-curcumin complexes (MCCs) to ameliorate endometriotic lesions were investigated. While all of the MCCs exhibited low hemolytic activity, their chemical and biological activities were largely dependent on the nature of the metal ion conjugated to the curcumin molecule. Copper-curcumin and nickel-curcumin complexes demonstrated superior therapeutic efficacy evidenced by enhanced antioxidant activity, selective cytotoxicity and increased accumulation in endometriotic cells mediated by an energy-dependent active transport process.

Biophysical Evaluation of Water-Soluble Curcumin Encapsulated in β-Cyclodextrins on Colorectal Cancer Cells

Curcumin (CUR), a curcuminoid originating from turmeric root, possesses diverse pharmacological applications, including potent anticancer properties. However, the use of this efficacious agent in cancer therapy has been limited due to low water solubility and poor bioavailability. To overcome these problems, a drug delivery system was established as an excipient allowing improved dispersion in aqueous media coupled with enhanced in vitro anticancer effects. Different analyses such as UV-vis spectroscopy, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), solubility and dissolution assays were determined to monitor the successful encapsulation of CUR within the inner cavity of a β-cyclodextrin (β-CD) complex. The results indicated that water solubility was improved by 205.75-fold compared to pure CUR. Based on cytotoxicity data obtained from MTT assays, the inclusion complex exhibited a greater decrease in cancer cell viability compared to pure CUR. Moreover, cancer cell migration rates were decreased by 75.5% and 38.92%, invasion rates were decreased by 37.7% and 35.7%, while apoptosis rates were increased by 26.3% and 14.2%, and both caused caspase 3 activation toward colorectal cancer cells (SW480 and HCT116 cells). This efficacious formulation that enables improved aqueous dispersion is potentially useful and can be extended for various chemotherapeutic applications. Preliminary toxicity evaluation also indicated that its composition can be safely used in humans for cancer therapy.

Curcumin and Related Compounds in Cancer Cells: New Avenues for Old Molecules

Curcumin and related compounds are known for the large spectrum of activities. The chemical features of these compounds are important for their biological effects with a key role for the thiol-reactive α−β unsaturated carbonyl groups. Curcumin derivatives may overcome the limitation of the bioavailability of the parent compound, while maintaining the key chemical features responsible for biological activities. Curcumin and related compounds show anti-viral, anti-fungal, anti-microbial and anti-tumor activities. The therapeutic effects of curcumin, used as a supplement in cancer therapy, have been documented in various cancer types, in which inhibition of cell growth and survival pathways, induction of apoptosis and other cell death pathways have been reported. Curcumin-induced apoptosis has been linked both to the intrinsic and extrinsic apoptotic pathways. Necroptosis has also been involved in curcumin-induced toxicity. Among curcumin-induced effects, ferroptosis has also been described. The mechanism of curcumin toxicity can be triggered by reactive oxygen species-mediated endoplasmic reticulum stress. Curcumin targets have been identified in the context of the ubiquitin-proteasome system with evidence of inhibition of the proteasome proteolytic activities and cellular deubiquitinases. Curcumin has recently been shown to act on the tumor microenvironment with effects on cancer-associated fibroblasts and immune cells. The related product caffeic acid phenethyl ester has shown promising preclinical results with an effect on the inflammatory microenvironment. Here, we review the mechanisms underlying curcumin and derivatives toxicity towards cancer cells with particular emphasis on cell death pathways and the ubiquitin-proteasome system.

Osteoinductive activity of bisdemethoxycurcumin and its synergistic protective effect with human amniotic mesenchymal stem cells against ovariectomy-induced osteoporosis mouse model

Osteoporosis is a common disease characterized by skeletal fragility and microarchitectural deterioration. However, existing conventional drugs exhibit limited efficacy and can elicit severe adverse effects; moreover, and novel stem cell-based therapies have not exhibited sufficient therapeutic efficacy. Our hypothesis is that an appropriate osteogenic inducer may improve their therapeutic efficacy. In this study, we found that bisdemethoxycurcumin (BDMC) stimulates the differentiation of human amniotic mesenchymal stem cells (hAMSCs) into osteoblasts without inducing cytotoxicity. Here BDMC enhances calcium deposition in hAMSCs, while promoting the expression of early and late markers of osteoblast differentiation, including ALP, runt-related transcription factor 2, osterix, COL1-α1, osteocalcin, and osteopontin at the transcriptional and translational levels. Mechanistically, BDMC was found to activate the JAK2/STAT3 pathway; whereas AG490 (JAK2/STAT3 pathway inhibitor) inhibited BDMC functioning. Subsequently, we found that the combinatorial therapy of BDMC and hAMSC had a positive synergistic effect on osteoporotic mouse model induced by bilateral ovariectomy, including inhibiting bone loss and bone resorption and improving bone micro-architecture. Moreover, BDMC inhibited production of the bone resorption markers C-terminal telopeptide of type I collagen, and tartrate resistant acid phosphatase, while promoting serum levels of bone formation markers OCN, and procollagen I N-terminal propeptide. BDMC also improved liver and kidney function in osteoporotic mouse model. Collectively, BDMC improved osteoporosis by enhancing hAMSC osteogenesis and exhibited a protective effect on liver and kidney function in an osteoporotic mouse model. Hence, BDMC may serve as an effective adjuvant, and combined therapy with hAMSCs is a promising new approach toward osteoporosis treatment.

Solid-State Fluorescent Selenium Quantum Dots by a Solvothermal-Assisted Sol-Gel Route for Curcumin Sensing

Toward the need for solid-state fluorescent quantum dots, resistant to self-quenching, we describe a solvothermal-assisted sol-gel method to synthesize Se quantum dots. Morphological and crystalline characterizations reveal that Se quantum dots (average size 3-8 nm) have a trigonal crystal structure. The presence of planar defects (dislocations, stacking faults, twins, and grain boundaries) suggests formation of Se nanocrystallites through aggregation-based crystal growth mechanisms. Under ultraviolet excitation, the quantum dots exhibit an excitation wavelength-dependent solid-state blue emission with an average lifetime of 1.96 ns. Depending on fluorescence quenching by curcumin, selenium quantum dots act as ideal candidates for inner filter effect-based curcumin sensing.

Enniatin B induces dosage-related apoptosis or necrosis in mouse blastocysts leading to deleterious effects on embryo development

The current study has focused on the effects of enniatin B (ENN B, a major mycotoxin produced by Fusarium fungi) on early embryonic development. In in vitro analysis, mouse blastocysts were incubated in medium with ENN B (0-40 μM) or 0.5% DMSO (control group) for 24 hours. In an animal study, blastocysts were collected from mice which were intravenously injected with ENN B (1, 3, 5, and 7mg/kg body weight/day) for 4 days in order to analyze apoptosis and necrosis via Annexin V/PI staining assay; and proliferation using dual differential staining. Exposure to low ENN B concentration (10 μM in vitro and 3 mg/kg/day in vivo) promoted Reactive Oxygen Species (ROS) generation and apoptosis in the Inner Cell Mass (ICM), the mass of cells inside the blastocyst, impairing post-implantation development alone. On the other hand, exposure to a higher ENN B concentration (40 μM in vitro and 7 mg/kg/day in vivo) induced ROS generation and decreased in intracellular ATP which encouraged necrotic processes in both trophectoderm (TE) and ICM of blastocysts leading to impaired implantation and post-implantation development. Moreover, 5 and 7 mg/kg/day ENN B intraperitoneal injection to female mice for 4 days has caused downregulation of CXCL1, IL-1β and IL-8 expressions and increased ROS generation in the liver of newborn mice. Over all, ENN B can induce apoptosis and/or necrosis depending on the treatment dosage in mouse blastocysts. ENN B-induced necrosis in blastocysts may exert long-term harmful effects on next-generation newborns.

Novel 3'-Substituted-1',2',4'-Oxadiazole Derivatives of 18βH-Glycyrrhetinic Acid and Their O-Acylated Amidoximes: Synthesis and Evaluation of Antitumor and Anti-Inflammatory Potential In Vitro and In Vivo

A series of novel 18βH-glycyrrhetinic acid (GA) derivatives containing 3'-(alkyl/phenyl/pyridin(-2″, -3″, and -4″)-yl)-1',2',4'-oxadiazole moieties at the C-30 position were synthesized by condensation of triterpenoid's carboxyl group with corresponding amidoximes and further cyclization. Screening of the cytotoxicity of novel GA derivatives on a panel of tumor cell lines showed that the 3-acetoxy triterpenoid intermediates-O-acylated amidoxime 3a-h-display better solubility under bioassay conditions and more pronounced cytotoxicity compared to their 1',2',4'-oxadiazole analogs 4f-h (median IC50 = 7.0 and 49.7 µM, respectively). Subsequent replacement of the 3-acetoxy group by the hydroxyl group of pyridin(-2″, 3″, and -4″)-yl-1',2',4'-oxadiazole-bearing GA derivatives produced compounds 5f-h, showing the most pronounced selective toxicity toward tumor cells (median selectivity index (SI) > 12.1). Further detailed analysis of the antitumor activity of hit derivative 5f revealed its marked proapoptotic activity and inhibitory effects on clonogenicity and motility of HeLa cervical carcinoma cells in vitro, and the metastatic growth of B16 melanoma in vivo. Additionally, the comprehensive in silico study revealed intermediate 3d, bearing the tert-butyl moiety in O-acylated amidoxime, as a potent anti-inflammatory candidate, which was able to effectively inhibit inflammatory response induced by IFNγ in macrophages in vitro and carrageenan in murine models in vivo, probably by primary interactions with active sites of MMP9, neutrophil elastase, and thrombin. Taken together, our findings provide a basis for a better understanding of the structure-activity relationship of 1',2',4'-oxadiazole-containing triterpenoids and reveal two hit molecules with pronounced antitumor (5f) and anti-inflammatory (3d) activities.

Side Effects of Curcumin: Epigenetic and Antiproliferative Implications for Normal Dermal Fibroblast and Breast Cancer Cells

Background: Curcumin is a yellow-orange pigment obtained from the plant Curcuma longa, which is known to exert beneficial effects in several diseases, including cancer. However, at high doses, it may produce toxic and carcinogenic effects in normal cells. In this context, we studied the effects of curcumin on normal human dermal fibroblast (HDF) cells and breast cancer cells (MCF7). Methods: We used cellular viability and growth assays to evaluate the antiproliferative action of curcumin, analyzed the endogenous glutathione levels, conducted cell cycle, apoptosis, and necrosis analyses, and performed immunodetection of glutathionylated and acetylated H3 histones. Results: We found that HDFs are more sensitive to curcumin treatment than MCF7 cells, resulting in pronounced arrest of cell cycle progression and higher levels of cellular death. In both cell types, the homeostasis of the redox cellular environment did not change after curcumin treatment; however, significant differences were observed in glutathione (GSH) levels and in S-glutathionylation of H3 histones. Conclusion: Curcumin administration can potentially confer benefits, but high doses may be toxic. Thus, its use as a dietary supplement or in cancer therapies has a double edge.

One-step microwave-assisted preparation of oxygen-rich multifunctional carbon quantum dots and their application for Cu2+-curcumin detection

Carbon quantum dots (CQDs), owing to its unique optical properties, have achieved tremendous progress for the detection of different metal ions, organic small molecules, macromolecules, etc. Here we synthesized fluorescent CQDs by a simple one-step microwave-assisted method using 3,4-Dihydroxy-l-phenylalanine (levodopa) as the carbon resource. The CQDs proved to be a multifunctional probe which can be used for detection of various species including copper ion, biothiols and curcumin, via different mechanisms. The selective detection of copper ion was obtained by fluorescence quenching and the mechanism was proved to be static quenching by electrostatic interaction. The fluorescence of levoCQDs-Cu²⁺ system can be recovered by biothiols (GSH, Cys and Hcy), implying levoCQDs-Cu²⁺ system can also be applied for biothiols detection. The excitation spectrum of levoCQDs had a good overlap with the absorption peak of curcumin, making it as a suitable curcumin probe by fluorescence quenching via inner filter effect (IFE). Furthermore, the levoCQDs can also track the formation of Cu²⁺-Curcumin complexes by restoring the fluorescence of the CQDs in levoCQDs and Cu²⁺-Curcumin system, and this feature may be exploited in the mechanism study of Cu²⁺-Curcumin in the treatment of Alzheimer's disease. The fluorescent levoCQDs were finally used for Cu²⁺ and curcumin detection in some real samples including different types of environmental water samples and human serum samples, providing a convenient strategy to monitor Cu²⁺and curcumin in environmental and biological samples.

Effects of curcumin on haematological values, immunity, antioxidant status and resistance of rainbow trout (Oncorhynchus mykiss) against Aeromonas salmonicida subsp. achromogenes

The present study was conducted to evaluate the effects of various levels of dietary curcumin on growth performance, haematological values, immunity and protection against Aeromonas salmonicida subsp. achromogenes infection in rainbow trout, Oncorhynchus mykiss. Fish were fed with diets containing different levels of curcumin; 0% (C), %1 (E1), %2 (E2) and %4 (E3), as treatment groups. After 8 weeks of feeding, the growth performance [weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR)], haematological values [the red blood cell (RBC) count, haemoglobin (Hb) concentration, haematocrit (Ht) level and erythrocyte indices: mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC)], various immune parameters [white blood cell (WBC) count, oxidative radical production (nitroblue tetrazolium (NBT) assay), phagocytic activity (PA) and phagocytic index (PI), total protein (TP) and immunoglobulin M (IgM) levels, serum bactericidal (BA), lysozyme (LYZ) and myeloperoxidase (MPO) activities] and antioxidant capacity [tissue malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities] were analysed. In addition, fish were challenged by Aeromonas salmonicida subsp. achromogenes and survival rate was recorded for 14 days. The results indicated that the growth performance was significantly influenced by the dietary curcumin levels, the maximal WG and SGR occurred at fish fed the diet containing 2% curcumin. Fish fed the diet containing curcumin had lower FCR than those fed the control diet. The RBC count, Hb concentration, and Ht level increased in the groups fed with curcumin when compared with the control group. However, there were no significant differences in the MCV, MCH and MCHC values among experimental groups. All the chosen immune parameters were enhanced in the groups fed diets containing curcumin. Also, the relative percentage survivals were higher in the groups fed with curcumin, especially in the E2 group, compared to the control. The dietary curcumin stimulated the SOD, CAT and GSH-Px activities in liver, head kidney and spleen as compared to the control group; however, a reverse trend was observed in the MDA levels of tissues. The highest values for haematological, immunological (except TP level of E3 group) and antioxidant parameters were found in the E2 group. These results collectively suggest that curcumin can be used in aquaculture to improve the growth, haematological values, immune responses, antioxidant capacity and disease resistance of rainbow trout, O. mykiss.

Comparison between curcumin and all-trans retinoic acid in the osteogenic differentiation of mouse bone marrow mesenchymal stem cells

The use of bone marrow mesenchymal stem cells (BMSCs) has great potential in cell therapy, particularly in the orthopedic field. BMSCs represent a valuable renewable cell source that have been successfully utilized to treat damaged skeletal tissue and bone defects. BMSCs can be induced to differentiate into osteogenic lineages via the addition of inducers to the growth medium. The present study examined the effects of all-trans retinoic acid (ATRA) and curcumin on the osteogenic differentiation of mouse BMSCs. Morphological changes, the expression levels of the bone-associated gene markers bone morphogenetic protein 2, runt-related transcription factor and osterix during differentiation, an in vitro mineralization assay, and changes in osteocalcin expression revealed that curcumin supplementation promoted the osteogenic differentiation of BMSCs. By contrast, the application of ATRA increased osteogenic differentiation during the early stages, but during the later stages, it decreased the mineralization of differentiated cells. In addition, to the best of our knowledge, the present study is the first to examine the effect of curcumin on the osteogenic potency of mouse embryonic fibroblasts (MEFs) after reprogramming with human lim mineralization protein (hLMP-3), which is a positive osteogenic regulator. The results revealed that curcumin-supplemented culture medium increased hLMP-3 osteogenic potency compared with that of MEFs cultured in the non-supplemented medium. The present results demonstrate that enrichment of the osteogenic culture medium with curcumin, a natural osteogenic inducer, increased the osteogenic differentiation capacity of BMSCs as well as that of MEFs reprogrammed with hLMP-3.

A di-functional and label-free carbon-based chem-nanosensor for real-time monitoring of pH fluctuation and quantitative determining of Curcumin

A nitrogen and sulfur dual-doped carbon nanodots (N,S-CNDs) sample was fabricated by an one-step hydrothermal treatment of acid fuchsin. The obtained N,S-CNDs possess yellow fluorescent, excellent water solubility, high fluorescence stability and religious biocompatibility, which can be used as a di-functional and label-free chem-nanosensor for the determination of pH and curcumin (Cur). When the pH is decreased from 8.0 to 4.4, the N,S-CNDs reveals an extraordinary emission escalation at emission wavelength (λ_em) of 543 nm, and the pK_a value of the N,S-CNDs was calculated as 6.06. The N,S-CNDs displays a favourable linear relationship in the physiological pH range of 5.0-7.4, which is meaningful for the research of near-neutral cytosolic pH. Furthermore, the laser scanning confocal microscopic images of intracellular distribution and the determination of pH in HeLa cells were successfully carried out, implying that the N,S-CNDs possess excellent cell membrane permeability and are capable of being further applied to real-time pH fluctuations monitoring in live cells with negligible autofluorescence. More importantly, the fluorescence of N,S-CNDs may be dramatically quenched by Cur via a combination of electrostatic and hydrogen-bond interaction and fluorescence inner filter effect (FIFE). The limit of detection is as low as 81 nmol/L Cur, and the linearity range is 0.5-20 μmol/L Cur. Ultimately, a satisfactory result was obtained when applying the as-constructed fluorescent chem-nanosensing system for the analyses of Cur in practical samples.

Chlorpyrifos-induced biochemical changes in Cyprinus carpio: Ameliorative effect of curcumin

The aim of this study was to determine protective effects of curcumin on some haematological values and oxidant/antioxidant status in Cyprinus carpio exposed to chlorpyrifos. The fish were exposed to two sublethal concentrations of chlorpyrifos (0.040 and 0.080mgL), and curcumin (100mg per kg of fish weight) was simultaneously administered for 14 days. Blood and tissue (liver, kidney, and gill) samples were collected at the end of the experiment and analysed to determine the haematological profile (red blood cell count, white blood cell count, haemoglobin concentration, and haematocrit level) and oxidant/antioxidant status (malondialdehyde level and superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase activities) of the fish. There was a significant decrease in the red blood cell count, the haemoglobin concentration, and the haematocrit level and a increase in the white blood cell count of CPF-treated fish. The results revealed a significant increase in the malondialdehyde levels of the groups that were exposed to CPF. Conversely, the MDA levels were significantly decreased by curcumin. Also, CPF exposure caused a significant increase in the superoxide dismutase and glutathione-S-transferase activities and a significant decrease in the catalase and glutathione peroxidase activities. However, curcumin reversed the superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase activities. In conclusion, this study demonstrated that CPF had a negative effect on the haematological values and the oxidant/antioxidant status of the fish. The simultaneous administration of curcumin was neutralised CPF-induced toxicity.

Correction to: In Vitro-In Vivo Dose Response of Ursolic Acid, Sulforaphane, PEITC, and Curcumin in Cancer Prevention

The citation of the author name "Ah-Ng Tony Kong" in PubMed is not the author's preference. Instead of "Kong AT", the author prefers "Kong AN".

Polyhydric polymer-loaded pyrene composites as powerful adsorbents and fluorescent probes: highly efficient adsorption and test strips-based fluorimetric analysis of curcumin in urine and plant extracts

A polyhydric polymer fluorescent probe was designed for the accumulation and fluorimetric detection of curcumin (Cur).

In Vitro-In Vivo Dose Response of Ursolic Acid, Sulforaphane, PEITC, and Curcumin in Cancer Prevention

According to the National Center of Health Statistics, cancer was the culprit of nearly 600,000 deaths in 2016 in the USA. It is by far one of the most heterogeneous diseases to treat. Treatment for metastasized cancers remains a challenge despite modern diagnostics and treatment regimens. For this reason, alternative approaches are needed. Chemoprevention using dietary phytochemicals such as triterpenoids, isothiocyanates, and curcumin in the prevention of initiation and/or progression of cancer poses a promising alternative strategy. However, significant challenges exist in the extrapolation of in vitro cell culture data to in vivo efficacy in animal models and to humans. In this review, the dose at which these phytochemicals elicit a response in vitro and in vivo of a multitude of cellular signaling pathways will be reviewed highlighting Nrf2-mediated antioxidative stress, anti-inflammation, epigenetics, cytoprotection, differentiation, and growth inhibition. The in vitro-in vivo dose response of phytochemicals can vary due, in part, to the cell line/animal model used, the assay system of the biomarker used for the readout, chemical structure of the functional analog of the phytochemical, and the source of compounds used for the treatment study. While the dose response varies across different experimental designs, the chemopreventive efficacy appears to remain and demonstrate the therapeutic potential of triterpenoids, isothiocyanates, and curcumin in cancer prevention and in health in general.

Molecular signaling mechanisms behind polyphenol-induced bone anabolism

For millennia, in the different cultures all over the world, plants have been extensively used as a source of therapeutic agents with wide-ranging medicinal applications, thus becoming part of a rational clinical and pharmacological investigation over the years. As bioactive molecules, plant-derived polyphenols have been demonstrated to exert many effects on human health by acting on different biological systems, thus their therapeutic potential would represent a novel approach on which natural product-based drug discovery and development could be based in the future. Many reports have provided evidence for the benefits derived from the dietary supplementation of polyphenols in the prevention and treatment of osteoporosis. Polyphenols are able to protect the bone, thanks to their antioxidant properties, as well as their anti-inflammatory actions by involving diverse signaling pathways, thus leading to bone anabolic effects and decreased bone resorption. This review is meant to summarize the research works performed so far, by elucidating the molecular mechanisms of action of polyphenols in a bone regeneration context, aiming at a better understanding of a possible application in the development of medical devices for bone tissue regeneration.

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

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

Curcumin potentiates the effect of chemotherapy against acute lymphoblastic leukemia cells via downregulation of NF-κB

Acute lymphoblastic leukemia (ALL) accounts for 30% of all pediatric cancers. Currently available treatments exhibit toxicity and certain patients may develop resistance. Thus, less toxic and chemoresistance-reversal agents are required. In the present study, the potential effect of curcumin, a component of Curcuma longa, as a pharmacological co-adjuvant of several chemotherapeutic agents against ALL, including prednisone, 6-mercaptopurine, dexamethasone, cyclophosphamide, l-asparaginase, vincristine, daunorubicin, doxorubicin, methotrexate and cytarabine, was investigated in the REH ALL cell line cultures treated in combination with chemotherapeutic agents and curcumin. The results of cell viability, gene expression and activation of NF-κB and caspase 3 indicated that curcumin potentiates the anticancer effects of the aforementioned chemotherapeutic agents in the REH ALL cell line. Following treatment with the above chemotherapeutic agents, curcumin enhanced caspase-3 activation and downregulated nuclear factor-kappa B (NF-κB) activation. Curcumin also downregulated the oxidative stress induced by certain chemotherapies. Notably, curcumin did not affect the gene expression of cell survival proteins such as B-cell lymphoma (Bcl)-2, Bcl-extra large, survivin, c-Myc and cyclin D1, which are regulated by the NF-κB transcription factor. In conclusion, curcumin has the potential to improve the effect of chemotherapeutic agents against ALL.

Curcumin and Osteosarcoma: Can Invertible Polymeric Micelles Help?

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

The evidence for natural therapeutics as potential anti-scarring agents in burn-related scarring

Though survival rate following severe thermal injuries has improved, the incidence and treatment of scarring have not improved at the same speed. This review discusses the formation of scars and in particular the formation of hypertrophic scars. Further, though there is as yet no gold standard treatment for the prevention or treatment of scarring, a brief overview is included. A number of natural therapeutics have shown beneficial effects both in vivo and in vitro with the potential of becoming clinical therapeutics in the future. These natural therapeutics include both plant-based products such as resveratrol, quercetin and epigallocatechin gallate as examples and includes the non-plant-based therapeutic honey. The review also includes potential mechanism of action for the therapeutics, any recorded adverse events and current administration of the therapeutics used. This review discusses a number of potential 'treatments' that may reduce or even prevent scarring particularly hypertrophic scarring, which is associated with thermal injuries without compromising wound repair.

Therapeutic actions of curcumin in bone disorders

Curcumin is the active component of turmeric extract derived from the Curcuma longa plant. In the last decade, curcumin has raised a considerable interest in medicine owing to its negligible toxicity and multiple therapeutic actions including anti-cancer, anti-inflammatory and anti-microbial activities. Among the various molecular targets of curcumin, some are involved in bone remodeling, which strongly suggests that curcumin can affect the skeletal system. The review sheds light on the current and potential applications of curcumin to treat bone disorders characterized by an excessive resorption activity. Within the scope of this review, the novel formulations of curcumin to overcome its physico-chemical and pharmacokinetic constraints are also discussed.

Attenuation of hind-limb suspension-induced bone loss by curcumin is associated with reduced oxidative stress and increased vitamin D receptor expression

Treatment with curcumin attenuated modeled microgravity-induced bone loss, possibly through abating oxidative stress and activating vitamin D receptor. Curcumin might be an effective countermeasure for microgravity-induced bone loss but remains to be tested in humans.

INTRODUCTION

Bone loss is one of the most important complications for human crewmembers who are exposed to long-term microgravity in space and also for bedridden people. The aim of the current study was to elucidate whether treatment with curcumin attenuated bone loss induced by microgravity.

METHODS

We used hind-limb suspension (HLS) and rotary wall vessel bioreactor (RWVB) to model microgravity in vivo and in vitro, respectively. We investigated the effects of curcumin consumption (40 mg kg(-1) body weight day(-1), via daily oral gavages) on Sprague-Dawley (SD) rats exposed to HLS for 6 weeks. Then, we investigated the effects of incubation with curcumin (4 μM) on MC3T3-E1 and RAW264.7 cells cultured in RWVB.

RESULTS

Curcumin alleviated HLS-induced reduction of bone mineral density in tibiae and preserved bone structure in tibiae and mechanical strength in femurs. Curcumin alleviated HLS-induced oxidative stress marked by reduced malondialdehyde content and increased total sulfhydryl content in femurs. In cultured MC3T3-E1 cells, curcumin inhibited modeled microgravity-induced reactive oxygen species (ROS) formation and enhanced osteoblastic differentiation. In cultured RAW264.7 cells, curcumin reduced modeled microgravity-induced ROS formation and attenuated osteoclastogenesis. In addition, curcumin upregulated vitamin D receptor (VDR) expression in femurs of rats exposed to HLS and MC3T3-E1 cells exposed to modeled microgravity.

CONCLUSION

Curcumin alleviated HLS-induced bone loss in rats, possibly via suppressing oxidative stress and upregulating VDR expression.

Evaluation of the protective effects of curcuminoid (curcumin and bisdemethoxycurcumin)-loaded liposomes against bone turnover in a cell-based model of osteoarthritis

Curcumin (Cur) and bisdemethoxycurcumin (BDMC), extracted from Curcuma longa, are poorly water-soluble polyphenol compounds that have shown anti-inflammatory potential for the treatment of osteoarthritis. To increase cellular uptake of Cur and BDMC in bone tissue, soybean phosphatidylcholines were used for liposome formulation. In this study, curcuminoid (Cur and BDMC)-loaded liposomes were characterized in terms of particle size, encapsulation efficiency, liposome stability, and cellular uptake. The results show that there is about 70% entrapment efficiency of Cur and BDMC in liposomes and that particle sizes are stable after liposome formation. Both types of liposome can inhibit macrophage inflammation and osteoclast differential activities. In comparison with free drugs (Cur and BDMC), curcuminoid-loaded liposomes were less cytotoxic and expressed high cellular uptake of the drugs. Of note is that Cur-loaded liposomes can prevent liposome-dependent inhibition of osteoblast differentiation and mineralization, but BDMC-loaded liposomes could not. With interleukin (IL)-1β stimulation, curcuminoid-loaded liposomes can successfully downregulate the expression of inflammatory markers on osteoblasts, and show a high osteoprotegerin (OPG)/receptor activator of nuclear factor κB ligand (RANKL) ratio to prevent osteoclastogenesis. In the present study, we demonstrated that Cur and BDMC can be successfully encapsulated in liposomes and can reduce osteoclast activity and maintain osteoblast functions. Therefore, curcuminoid-loaded liposomes may slow osteoarthritis progression.

Nitrogen-doped carbon dots as fluorescent probe for detection of curcumin based on the inner filter effect

A facile, economical and green one-step hydrothermal method for N-doped CDs was presented by using citric acid as carbon source and urea as nitrogen source. The fluorescence of N-doped CDs quenched dramatically from curcumin via inner filter effect.

Curcumin-functionalized silk materials for enhancing adipogenic differentiation of bone marrow-derived human mesenchymal stem cells

Curcumin, a natural phenolic compound derived from the plant Curcuma longa, was physically entrapped and stabilized in silk hydrogel films, and its influence on human bone marrow-derived mesenchymal stem cells (hBMSC) was assessed related to adipogenic differentiation. The presence of curcumin significantly reduced the silk gelation time and changed the porous morphology of gel matrix, but did not change the formation of the silk beta-sheet structure. Based on spectrofluorimetric analysis, curcumin most likely interacted with hydrophobic residues in silk, interacting with the beta-sheet domains formed in the hydrogels. The antioxidant activity of silk film-associated curcumin remained functional over at least one month in both the dry and hydrated state. Negligible curcumin was released from silk hydrogel films over 48 h incubation in aqueous solution. For hBMSC cultured on silk films containing more than 0.25 mg ml(-1) curcumin, cell proliferation was inhibited, while adipogenesis was significantly promoted based on transcripts as well as Oil Red O staining. When hBMSC were cultured in media containing free curcumin, both proliferation and adipogenesis of hBMSC were inhibited when curcumin concentrations exceeded 5 μM, which is more than 1000 times higher than the level of curcumin released from the films in aqueous solution. Thus, silk film-associated curcumin exhibited different effects on hBMSC proliferation and differentiation compared with curcumin in solution.

Short communication: selective cytotoxicity of curcumin on osteosarcoma cells compared to healthy osteoblasts

Curcumin is a natural phenolic compound extracted from the plant Curcuma longa L. In previous studies, curcumin has been shown to have anticancer, antioxidant, and anti-inflammatory effects. In this study, the cytotoxicity of different concentrations (5, 10, 25, 50, 75, and 100 μM) of curcumin dissolved in dimethyl sulfoxide was compared between MG-63 osteosarcoma and healthy human osteoblast cells. Consequently, the viability of osteosarcoma cells was less than 50% at a concentration of 10 μM compared to the control sample without curcumin, but healthy osteoblast cells had at least 80% viability throughout all the concentrations tested. The results demonstrated that MG-63 osteosarcoma cells were much more sensitive in terms of cytotoxicity to curcumin, while the healthy human osteoblasts exhibited a higher healthy viability after 24 hours of curcumin treatment. Therefore, this study showed that at the right concentrations (5 μM to 25 μM), curcumin, along with a proper nanoparticle drug delivery carrier, may selectively kill bone cancer cells over healthy bone cells.

Visible light is a better co-inducer of apoptosis for curcumin-treated human melanoma cells than UVA

Curcumin attracts worldwide scientific interest due to its anti-proliferative and apoptosis inducing effects on different tumor cells at concentrations ranging from 10 to 150 µM (3.7-55 µg/ml). Unfortunately, because of a low oral bioavailability, only low and pharmacologically ineffective serum levels are achievable. In this study, an alternative treatment concept consisting of low concentration curcumin (0.2-5 µg/ml) and irradiation with UVA or visible light (VL) has been tested. The experimental results show clearly that this treatment decreases the proliferation and the viability of human melanoma cells while the cell membrane integrity remains intact. We identified the onset of apoptosis characterized by typical markers such as active caspases 8, 9 and 3 as well as DNA fragmentation accompanied by the loss of cell adhesion. The mitochondrial apoptosis signaling pathway is predominant due to an early activation of caspase-9. The present data indicate a higher efficacy of a combination of curcumin and VL than curcumin and UVA. Reduced effects as a result of light absorption by heavily pigmented skin are unlikely if VL is used. These results indicate that a combination of curcumin and light irradiation may be a useful additional therapy in the treatment of malignant disease.

Effects of curcumin on the proliferation and mineralization of human osteoblast-like cells: implications of nitric oxide

Curcumin (diferuloylmethane) is found in the rhizomes of the turmeric plant (Curcuma longa L.) and has been used for centuries as a dietary spice and as a traditional Indian medicine used to treat different conditions. At the cellular level, curcumin modulates important molecular targets: transcription factors, enzymes, cell cycle proteins, cytokines, receptors and cell surface adhesion molecules. Because many of the curcumin targets mentioned above participate in the regulation of bone remodeling, curcumin may affect the skeletal system. Nitric oxide (NO) is a gaseous molecule generated from l-arginine during the catalization of nitric oxide synthase (NOS), and it plays crucial roles in catalization and in the nervous, cardiovascular and immune systems. Human osteoblasts have been shown to express NOS isoforms, and the exact mechanism(s) by which NO regulates bone formation remain unclear. Curcumin has been widely described to inhibit inducible nitric oxide synthase expression and nitric oxide production, at least in part via direct interference in NF-κB activation. In the present study, after exposure of human osteoblast-like cells (MG-63), we have observed that curcumin abrogated inducible NOS expression and decreased NO levels, inhibiting also cell prolifieration. This effect was prevented by the NO donor sodium nitroprusside. Under osteogenic conditions, curcumin also decreased the level of mineralization. Our results indicate that NO plays a role in the osteoblastic profile of MG-63 cells.

Enhanced apoptotic effect of curcumin loaded solid lipid nanoparticles

Curcumin is reported to show potent in vitro anticancer effects in a surfeit of human cancer cell lines and majorly in the carcinogenesis of GIT, in animals. Its poor pharmacokinetics and stability limit its vivo clinical efficacy for the other systemic cancers. We recently reported on a 32-155 times enhancement in bioavailability of curcumin when incorporated into solid lipid nanoparticles (C-SLNs). Presently we report on a 54-85% reduction in IC 50 values with developed C-SLNs in comparison to free curcumin against a panel of human cancer cell lines (HL-60, A549, and PC3). Results demonstrate mechanisms similar to those claimed for free curcumin, including induction of cellular apoptosis by activation of caspases, release of cyctochrome c, loss of membrane potential, blockade of nuclear factor kappa B (NF-κB) activation, and upregulation of TNF-R for C-SLNs. However, the extent of cell death provided by C-SLNs in all these tests was significantly higher (p < 0.001). This may be attributed to the presentation of curcumin in a dispersible/soluble form which enhanced permeability across the cell surface. The display of significantly better in vitro anticancer effect coupled with high in vivo bioavailability points toward a great potential of using C-SLNs for cancer therapeutics.

2-Deoxy-D-glucose cooperates with arsenic trioxide to induce apoptosis in leukemia cells: involvement of IGF-1R-regulated Akt/mTOR, MEK/ERK and LKB-1/AMPK signaling pathways

While the anti-tumor efficacy of 2-deoxy-D-glucose (2-DG) is normally low in monotherapy, it may represent a valuable radio- and chemo-sensitizing agent. We here demonstrate that 2-10 mM 2-DG cooperates with arsenic trioxide (ATO) and other antitumor drugs to induce apoptosis in human myeloid leukemia cell lines. Using ATO and HL60 as drug and cell models, respectively, we observed that 2-DG/ATO combination activates the mitochondrial apoptotic pathway, as indicated by Bid-, and Bax-regulated cytochrome c and Omi/HtrA2 release, XIAP down-regulation, and caspase-9/-3 pathway activation. 2-DG neither causes oxidative stress nor increases ATO uptake, but causes inner mitochondria membrane permeabilization as well as moderate ATP depletion, which nevertheless do not satisfactorily explain the pro-apoptotic response. Surprisingly 2-DG causes cell line-specific decrease in LKB-1/AMPK phosphorylation/activation, and also causes Akt/mTOR/p70S6K and MEK/ERK activation, which is prevented by co-treatment with ATO. The use of kinase-specific pharmacologic inhibitors and/or siRNAs reveals that apoptosis is facilitated by AMPK inactivation and restrained by Akt and ERK activation, and that Akt and ERK activation mediates AMPK inhibition. Finally, 2-DG stimulates IGF-1R phosphorylation/activation, and co-treatment with IGF-1R inhibitor prevents 2-DG effects on Akt, ERK and AMPK, and facilitates 2-DG-provoked apoptosis. In summary 2-DG elicits IGF-1R-mediated AMPK inactivation and Akt and ERK activation, which facilitates or restrain apoptosis, respectively. 2-DG-provoked AMPK inactivation increases the apoptotic efficacy of ATO, while in turn ATO-provoked Akt and ERK inactivation may increase the efficacy of 2-DG as anti-tumor drug.

Injurious effects of curcumin on maturation of mouse oocytes, fertilization and fetal development via apoptosis

Curcumin, a common dietary pigment and spice, is a hydrophobic polyphenol derived from the rhizome of the herb Curcuma longa. Previously, we reported a cytotoxic effect of curcumin on mouse embryonic stem cells and blastocysts and its association with defects in subsequent development. In the present study, we further investigated the effects of curcumin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, curcumin induced a significant reduction in the rate of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with curcumin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments with an in vivo mouse model disclosed that consumption of drinking water containing 40 μM curcumin led to decreased oocyte maturation and in vitro fertilization as well as early embryonic developmental injury. Finally, pretreatment with a caspase-3-specific inhibitor effectively prevented curcumin-triggered injury effects, suggesting that embryo impairment by curcumin occurs mainly via a caspase-dependent apoptotic process.

Curcumin modulates nuclear factor kappaB (NF-kappaB)-mediated inflammation in human tenocytes in vitro: role of the phosphatidylinositol 3-kinase/Akt pathway

Inflammatory processes play essential roles in the pathogenesis of tendinitis and tendinopathy. These events are accompanied by catabolic processes initiated by pro-inflammatory cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Pharmacological treatments for tendinitis are restricted to the use of non-steroidal anti-inflammatory drugs. Recent studies in various cell models have demonstrated that curcumin targets the NF-κB signaling pathway. However, its potential for the treatment of tendinitis has not been explored. Herein, we used an in vitro model of human tenocytes to study the mechanism of curcumin action on IL-1β-mediated inflammatory signaling. Curcumin at concentrations of 5-20 μm inhibited IL-1β-induced inflammation and apoptosis in cultures of human tenocytes. The anti-inflammatory effects of curcumin included down-regulation of gene products that mediate matrix degradation (matrix metalloproteinase-1, -9, and -13), prostanoid production (cyclooxygenase-2), apoptosis (Bax and activated caspase-3), and stimulation of cell survival (Bcl-2), all known to be regulated by NF-κB. Furthermore, curcumin suppressed IL-1β-induced NF-κB activation via inhibition of phosphorylation and degradation of inhibitor of κBα, inhibition of inhibitor of κB-kinase activity, and inhibition of nuclear translocation of NF-κB. Furthermore, the effects of IL-1β were abrogated by wortmannin, suggesting a role for the phosphatidylinositol 3-kinase (PI-3K) pathway in IL-1β signaling. Curcumin suppressed IL-1β-induced PI-3K p85/Akt activation and its association with IKK. These results demonstrate, for the first time, a potential role for curcumin in treating tendon inflammation through modulation of NF-κB signaling, which involves PI-3K/Akt and the tendon-specific transcription factor scleraxis in tenocytes.