Concentrations Of Curcumin Research Articles

Evaluating the effect of curcumin on the metacestode of Taenia crassiceps

Curcumin, a curcuminoid present in the rhizome of the plant Curcuma longa has multiple pharmacological effects including anticarcinogenic and anti-inflammatory properties. This work evaluates the anthelmintic effect of the curcumin molecule (98% pure) on Taenia crassiceps cysticerci viability in vitro. Cysticerci incubated in the presence of increasing concentrations of curcumin showed a dose-dependent mortality correlated with a significant increase in the production of reactive oxygen species and a partial inhibition of thioredoxin-glutathione reductase, the only disulfide reductase present in these parasites. At 500 μM curcumin, a 100% of cysticerci lethality was obtained after 2 h of treatment. These results suggest the curcumin-induced oxidative stress could be in the origin of the anthelminthic effect of curcumin. Mice with cysticerci were injected intraperitoneally with 20, 40, or 60 mM curcumin daily for 30 days. A decrease in the burden of cysticerci (46%) was observed with a 60 mM dose of curcumin, supporting this compound as a potential anthelmintic drug.

Formulated Curcumin Prevents Paclitaxel-Induced Peripheral Neuropathy through Reduction in Neuroinflammation by Modulation of α7 Nicotinic Acetylcholine Receptors

Paclitaxel is widely used in the treatment of various types of solid malignancies. Paclitaxel-induced peripheral neuropathy (PIPN) is often characterized by burning pain, cold, and mechanical allodynia in patients. Currently, specific pharmacological treatments against PIPN are lacking. Curcumin, a polyphenol of Curcuma longa, shows antioxidant, anti-inflammatory, and neuroprotective effects and has recently shown efficacy in the mitigation of various peripheral neuropathies. Here, we tested, for the first time, the therapeutic effect of 1.5% dietary curcumin and Meriva (a lecithin formulation of curcumin) in preventing the development of PIPN in C57BL/6J mice. Curcumin or Meriva treatment was initiated one week before injection of paclitaxel and continued throughout the study (21 days). Mechanical and cold sensitivity as well as locomotion/motivation were tested by the von Frey, acetone, and wheel-running tests, respectively. Additionally, sensory-nerve-action-potential (SNAP) amplitude by caudal-nerve electrical stimulation, electronic microscopy of the sciatic nerve, and inflammatory-protein quantification in DRG and the spinal cord were measured. Interestingly, a higher concentration of curcumin was observed in the spinal cord with the Meriva diet than the curcumin diet. Our results showed that paclitaxel-induced mechanical hypersensitivity was partially prevented by the curcumin diet but completely prevented by Meriva. Both the urcumin diet and the Meriva diet completely prevented cold hypersensitivity, the reduction in SNAP amplitude and reduced mitochondrial pathology in sciatic nerves observed in paclitaxel-treated mice. Paclitaxel-induced inflammation in the spinal cord was also prevented by the Meriva diet. In addition, an increase in α7 nAChRs mRNA, known for its anti-inflammatory effects, was also observed in the spinal cord with the Meriva diet in paclitaxel-treated mice. The use of the α7 nAChR antagonist and α7 nAChR KO mice showed, for the first time in vivo, that the anti-inflammatory effects of curcumin in peripheral neuropathy were mediated by these receptors. The results presented in this study represent an important advance in the understanding of the mechanism of action of curcumin in vivo. Taken together, our results show the therapeutic potential of curcumin in preventing the development of PIPN and further confirms the role of α7 nAChRs in the anti-inflammatory effects of curcumin.

Nanofibrous membranes with antibacterial and thermoregulatory functions fabricated by coaxial electrospinning

Bacteria, viruses, and temperatures change can affect the preservation of food and medicines, so it is necessary to develop an intelligent textile for antibacterial and thermal regulation. In this paper, we used coaxial electrospinning technology to achieve antibacterial thermo-regulating intelligent textiles. The polyacrylonitrile (PAN)/curcumin is the sheath, and n-octadecane is the core. The composite fiber has excellent comprehensive properties. When the curcumin concentration is 10 wt%, the antibacterial effect is the best, and the bacteriostatic rate is 100%. When the core feed rate is 0.25 mL/h, the latent heat can reach 123.94 J/g. The multifunctional textiles have potential application value in the clothing fabrics, preservation and storage quality of functional foods, biomedical products, and other fields.

Synergistic anti-inflammatory effects and mechanisms of the combination of resveratrol and curcumin in human vascular endothelial cells and rodent aorta

Chronic increased pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) play critical roles in the development of endothelial dysfunction and therefore induce cardiovascular disease. Although phytochemicals have the potential ability to reduce the risk of CVD, the big gap between required high concentration in cells and the low bioavailability in the blood of phytochemicals compromise their therapeutic potentials. This study aims to investigate if combined phytochemicals at low levels exert a synergistic anti-inflammatory effect and to define relevant molecular mechanisms. Our results found that combined curcumin (5 µM) and resveratrol (5 µM) synergistically (combination index is 0.78) inhibited TNF-α-induced monocytes adhesion to human endothelial EA.hy 926 cells while the individual chemicals did not have such effect at the selected concentrations. The concentrations of curcumin (5 µM) and resveratrol (5 µM) are very close to the maximum level of curcumin (3.56 µM) and resveratrol (2 µM) in human blood. Dietary supplementation of combined curcumin (500mg/kg) and resveratrol (200mg/kg) synergistically reduced TNF-α-induced vascular inflammation in C57BL/6 mice with a similar pattern in cells. Moreover, the combination ameliorated the TNF-α-induced protein expressions and circulating levels of vascular cell adhesion molecule 1 and monocyte chemotactic protein-1 in EA.hy 926 cells, mice aorta and serum. Furthermore, combined curcumin and resveratrol significantly inhibited TNF-α-induced nuclear factor-kappaB (NF-κB) p65 nuclear protein expression than that by the individual chemical alone in EA.hy 926 cells, indicating that the synergistic effect of the combination may result from that curcumin reduces the required minimum concentration for resveratrol to inhibit the nuclear translocation of NF-κB. In conclusion, the combination of curcumin and resveratrol protects against TNF-α-induced vascular inflammation by suppressing NF-κB signaling in vitro and in vivo models. This study suggests that dietary intake of a combination of curcumin and resveratrol or its foods may be a practical, safe approach to prevent vascular inflammation and therefore prevent/treat vascular diseases in humans.

PH-driven self-assembly of alcohol-free curcumin-loaded zein-propylene glycol alginate complex nanoparticles

This study aimed to prepare alcohol-free curcumin-loaded zein-propylene glycol alginate (zein-PGA-Cur) nanoparticles using the pH-driven method to enhance the bioavailability and physicochemical stability of curcumin. The prepared zein-PGA-Cur nanoparticles exhibited a small size (360 nm) and negative zeta-potential (−5.8 mV), as well as excellent physical stability, under storage conditions of pH 4.0 and temperature at 4 °C for 30 days. In addition, the Fourier transform infrared spectroscopy results demonstrated that the main interactions of pH-driven for the formation of zein-PGA-Cur nanoparticles were hydrogen bonding, hydrophobic, and electrostatic interactions. Fluorescence spectroscopy revealed that the curcumin-induced fluorescence quenching of zein was static. Circular Dichroism spectroscopy demonstrated that the pH-driven method mainly decreased the β-sheet structure of zein from 3.9 % to 1.4 %. Furthermore, the HT-29 colorectal adenocarcinoma cells viability experiments revealed that the prepared zein-PGA-Cur nanoparticles exhibited excellent biocompatibility. In vivo rat experiments also demonstrated that the prepared nanoparticles resulted in a higher plasma concentration of curcumin, representing a 7.2-fold enhancement in bioavailability compared with pure curcumin crystals. The findings of this study will provide a green and energy-saving method for the development of insoluble drug self-assembly systems and promote their wider applications in drug delivery.

Curcumin attenuates vascular calcification via the exosomal miR-92b-3p/KLF4 axis.

Vascular calcification (VC) is the most widespread pathological change in diseases of the vascular system. However, we do not have a good understanding of the molecular mechanisms and effective therapeutic approaches for VC. Curcumin (CUR) is a natural polyphenolic compound that has hypolipidemic, anti-inflammatory, and antioxidant effects on the cardiovascular system. Exosomes are known to have extensive miRNAs for intercellular regulation. This study investigated whether CUR attenuates VC by affecting the secretion of exosomal miRNAs. Calcification models were established in vivo and in vitro using vitamin D3 and β-glycerophosphate, respectively. Appropriate therapeutic concentrations of CUR were detected on vascular smooth muscle cells (VSMCs) using a cell counting kit 8. Exosomes were extracted by super speed centrifugation from the supernatant of cultured VSMCs and identified by transmission electron microscopy and particle size analysis. Functional and phenotypic experiments were performed in vitro to verify the effects of CUR and exosomes secreted by VSMCs treated with CUR on calcified VSMCs. Compared with the calcified control group, both CUR and exosomes secreted by VSMCs after CUR intervention attenuated calcification in VSMCs. Real-Time quantitative PCR (RT-qPCR) experiments showed that miR-92b-3p, which is important for alleviating VC, was expressed highly in both VSMCs and exosomes after CUR intervention. The mimic miR-92b-3p significantly decreased the expression of transcription factor KLF4 and osteogenic factor RUNX2 in VSMCs, while the inhibitor miR-92b-3p had the opposite effect. Based on bioinformatics databases and dual luciferase experiments, the prospective target of miR-92b-3p was determined to be KLF4. Both mRNA and protein of RUNX2 were decreased and increased in VSMCs by inhibiting and overexpressing of KLF4, respectively. In addition, in the rat calcification models, CUR attenuated vitamin D3-induced VC by increasing miR-92b-3p expression and decreasing KLF4 expression in the aorta. In conclusion, our study suggests that CUR attenuates vascular calcification via the exosomal miR-92b-3p/KLF4 axis.

Effect of Curcumin on Apoptosis of Acute T-Lymphoblastic Leukemia Cells induced by UMI-77 and Its Related Mechanism

T-ALL cell line Molt-4 was cultured, and the cells were treated with different concentrations of curcumin and Mcl-1 small molecule inhibitor UMI-77 for 24 h. The MTT method was used to detect the cell survival rate after different treatment; According to the results of curcumin and UMI-77, the experimental settings were divided into control group, curcumin group (20 μmol/L curcumin treated cells), UMI-77 group (15 μmol/L Mcl-1 small molecule inhibitor UMI-77 treated cells) and curcumin+ UMI-77 group (20 μmol/L curcumin and 15 μmol/L Mcl-1 small molecule inhibitor UMI-77 treated cells), MTT method was used to detect cell proliferation inhibition rate, Annexin V-FITC/PI double staining method and TUNEL staining were used to detect cell apoptosis, DCFH-DA probe was used to detect cell reactive oxygen species, JC-1 fluorescent probe was used to detect mitochondrial membrane potential, Western blot was used to detect the expression levels of apoptosis-related proteins and Notch1 signaling pathway-related proteins. After the treatment of Molt-4 cells with different concentrations of curcumin and Mcl-1 small molecule inhibitor UMI-77, the cell survival rate was decreased (P<0.05); Compared with the control group, the cell proliferation inhibition rate of the curcumin group and the UMI-77 group were increased, the apoptosis rate of cell was increased, the level of ROS was increased, the protein expression of Bax, Caspase-3 and Caspase-9 in the cells were all increased, and the protein expression of Bcl-2 was reduced (P<0.05); Compared with the curcumin group or UMI-77 group, the cell proliferation inhibition rate and apoptosis rate of the curcumin+UMI-77 group were further increased, and the level of ROS was increased. At the same time, the protein expression of Bax, Caspase-3 and Caspase-9 in the cells were all increased, the protein expression of Bcl-2 was reduced (P<0.05); In addition, the mitochondrial membrane potential of the cells after curcumin treatment was decreased, and the proteins expression of Notch1 and HES1 were reduced (P<0.05). Curcumin can enhance the apoptosis of T-ALL cells induced by Mcl-1 small molecule inhibitor UMI-77 by reducing the mitochondrial membrane potential, the mechanism may be related to the inhibition of Notch1 signaling pathway.

Curcumin Impact on Ex Vivo Toxocara vitulorum Adult Worms and Eggs

Conventional drug treatment expels adult worms from the intestinal tract but does not prevent reinfection and further contamination of the environment with eggs. This study was performed as the start of a program aiming to develop curcumin (CUR) as a lead drug for human and animal ascariasis. Ex vivo adult Toxocara vitulorum and eggs were exposed at 37°C for 4hr to different concentrations of CUR (0-500μM) in Roswell Memorial Park Institute (RPMI) 1640 medium supplemented with 2% dimethyl sulfoxide (DMSO). The results showed that CUR slightly impaired the viability and mobility of approximately 30% of worms in a dose-dependent manner. Scanning electron microscopy revealed changes in cuticles throughout the length of the roundworms exposed to high CUR concentrations. Enzyme-linked immunosorbent assay failed to reveal CUR effects on specific antibody binding to the roundworm surface membrane molecules. To mimic the in vivo situation, after incubation, eggs were washed, suspended in 0.1N sulphuric acids, and examined for development and maturation 4, 7, 11, and 18 days later. Eggs produced from CUR-exposed females showed an even more remarkable delay and impairment in development in comparison to eggs, which were directly exposed to CUR. A significant increase in the number of dead eggs and prevention of maturation to the infective stage were observed in a CUR dose and time-dependent manner. These results encourage investigations of CUR impact on human and animal ascarids of public health and economic importance.

Effects of ERCC5 rs751402 Polymorphism on Oxidative Stress and the Impact of Curcumin on Catalase Activity in Breast Carcinogenesis.

Background:Breast cancer is a complex multifactorial disease and polymorphisms in nucleotide excision repair pathway are associated with the potential risk of breast cancer. Pathological processes linked to breast cancer are associated with oxidative stress. Catalase plays an essential role in cell defense against oxidative stress. Curcumin has antioxidant activity that can significantly reduce oxidative stress levels. The aims of this study were to determine ERCC5 rs751402 polymorphism was associated with oxidative stress in breast carcinogenesis. The impact of curcumin on catalase activity for inhibiting breast cancer progression was also studied. Methods:The effect of ERCC5 rs751402 polymorphism on oxidative stress was studied with different H2O2 concentrations in HCC 1937 cell line for 24 h and then analysed by MTT assay. The impact of curcumin on catalase activity was studied in MCF-7 cell line treated with different curcumin concentrations for 24 h and then analysed by trypan blue exclusion assay and catalase activity assay. Results:It showed that this polymorphism involved in oxidative stress (p < 0.05) and curcumin caused the antiproliferative effect by the catalase activity increase (p < 0.05). Conclusion:Our study indicated that ERCC5 rs751402 polymorphism may contribute to the etiology of breast carcinogenesis about the failure of oxidative stress protection and lead to breast carcinogenesis. The antiproliferative effect of curcumin may be associated with catalase activity and protect breast carcinogenesis.

Fabrication of a pH-Responsive Magnetic Nanocarrier Based on Carboxymethyl Cellulose-Aminated Graphene Oxide for Loading and In-Vitro Release of Curcumin

In this study, a pH-responsive magnetic drug delivery system was prepared by cross-linking of Cofe2O4/graphene oxide to carboxymethyl cellulose (CMC) biopolymer with adipic acid dihydrazide (ADH) and then investigated for loading and release of a poorly water-soluble anti-cancer drug, curcumin (CUR). The CoFe2O4/GO-ADH-CMC bio-nanocomposite was characterized by FE–SEM/EDX, TEM, FT–IR, XRD, TGA, VSM, and zeta-potential techniques. The highest amount of drug loading was achieved as 23.7 mg g–1 at 323 K, pH 6.0, and 120 mg L–1 CUR concentration. The study of adsorption isotherms revealed that the Sips model was best fitted to the equilibrium data (R2 > 0.997 and RMSE < 0.48), which indicated the contribution of both chemisorption and physisorption in drug loading. Furthermore, the release profile of CUR from drug-loaded CoFe2O4/GO-ADH-CMC was studied in mimicking the endosomal (pH = 5.6) and physiological (pH = 7.4) conditions. After 24 h, the maximum cumulative releases were found to be 86 and 38% at pH = 5.6 and 7.4, respectively. Also, the Peppas-Sahlin kinetic model was followed for the release data. The MTT assay exhibited good biocompatibility of the CoFe2O4/GO-ADH-CMC. The results implied that CoFe2O4/GO-ADH-CMC magnetic bio-nanocomposite might be utilized as a potentially safe carrier with the continuous and slow release of CUR.Graphical Abstract

Inhibitory effects of curcumin and piperine on fluorescent advanced glycation end products formation in a bovine serum albumin–fructose model

SummaryThis study investigated the inhibitory effects of curcumin and piperine on fluorescent advanced glycation end products (fAGEs) formation in a bovine serum albumin (BSA)–fructose model. Model systems of BSA and fructose were prepared, and curcumin or piperine was added. fAGEs and BSA oxidation product (dityrosine, kynurenine and N'‐formylkynurenine) contents were determined. The results showed that fAGEs content decreased with increasing concentration of curcumin and piperine (P &lt; 0.05). Addition of curcumin and piperine at 160 µg mL−1 could inhibit fluorescent AGEs by 100% and 93% respectively. Dityrosine and N'‐formylkynurenine contents decreased as curcumin and piperine concentration increased (P &lt; 0.05). Furthermore, the result of principal component analysis indicated that curcumin and piperine markedly impeded BSA oxidation, resulting in a lower level of fAGEs in model systems. Therefore, adding curcumin and piperine may facilitate reduced fAGEs levels in BSA–fructose model.

The Effectivity of IC50 Test between Green Tea and Curcumin Extracts from Mt. Lawu as an Antioxidant for SOD and MDA Levels in a Cisplatin Rat Model

Abstract&#x0D; Purpose: This study aims to determine the relationship of the effective dose between Mt. Lawu green tea and Mt. Lawu curcumin as antioxidants based on superoxide dismutase (SOD) and malondialdehyde (MDA) levels.&#x0D; Methods: Blood was undertaken through the orbital sinus and allowed to stand until serum was formed. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was used to observe the effective dose of Mt. Lawu green tea and curcumin by quantifying the color change of each sample after incubation. The color change measured the absorbance value through a spectrophotometer. The data were analyzed using a correlation test to measure the effective concentration of Mt. Lawu green tea and Mt. Lawu curcumin toward SOD and MDA as antioxidant parameters in a cisplatin (CN) rat model.&#x0D; Result: The study results show that the IC50 green tea concentration of 0.75 ± 0.16 µg/mL and the curcumin concentration of 5.3 ± 0.4 µg/mL can reduce 50% of DPPH. Based on the graphs, SOD increased and MDA decreased.&#x0D; Discussion and Conclusion: This study demonstrates that the IC50 parameter of Mt. Lawu green tea and curcumin extracts is a good indicator for assigning the SOD and MDA levels in a CN rat model. Extracts derived from Mt. Lawu green tea and curcumin have ideal lowering DPPH, and the dosage has a strong relationship with the increase in SOD and the decrease in MDA.

Potential Drug Therapy For Fragile X Tremor/Ataxia Syndrome

Fragile X‐associated tremor/ataxia syndrome (FXTAS) is a late‐onset neurological disorder that affects carriers of the alleles for the Fragile X gene, Fragile X Mental Retardation (FMR1) due to the CGG triplet repeat expansion within the 5’UTR of FMR1. Clinical symptoms that are likely to occur are progressive ataxia, intention tremor, intranuclear inclusions, and Parkinsonian‐like motor symptoms. The goal of this research is to assess the biological efficacy of Curcumin, Muscadine Grape Seed Extract (MSKE) on the neuroprotective capacity with respect to mitochondrial damage, and their ability to restore mitochondrial health in patient with FXTAS. To establish mitochondrial dysfunction, normal human cell lines and human‐induced pluripotent cells were treated with multiple concentrations of glucose/ glucose oxidase (GluOx) at 2,12,and 24 hour time points to induce varying intensities of oxidative stress. The degrees of oxidative stress were measured by apoptosis and mitochondrial reactive oxygen species (ROS) production. Curcumin and MSKE, compounds effective against oxidative damage in mitochondria, were used to rescue glucose oxidase induced oxidative damage in both cell lines. To test the ability of these drugs to restore mitochondrial health, cell viability and cellular superoxide production were assessed by propidium iodide and the MitoSox fluorescence assay, respectively. We anticipated that GluOx at varying concentrations and time points would proportionally increase levels of apoptosis and mitochondrial ROS, reflective of mitochondrial damage, with the most severe dysfunction occurring at a dose of 25 nM and the longest duration of 24‐hr exposure. Administration of MSKE in concentrations ranging from 10‐8 to 10‐5 M in half log increments, did not reverse the oxidative defects induced in the cell lines. However, curcumin concentrations increased cell viability at the 2, 12, and 24 hour time period. Results indicate that the research design should be modified by increasing concentration of both glucose and MSKE to provide a reliable test of the hypothesis. Although, the research design will be modified to better assessed the hypothesis, the overall research is translational in that it lends flexibility to testing therapeutics in neuronal FXTAS models and expands the discovery of mitochondrial markers for the syndrome.

Human prostate cancer cell epithelial-to-mesenchymal transition as a novel target of arsenic trioxide and curcumin therapeutic approach

BackgroundArsenic trioxide (As2O3) as an inorganic compound is used to treat various cancers and other diseases. It has been reported that arsenic trioxide induced cellular apoptosis in certain kinds of cancers, including prostate cancers. The present study aimed to elucidate the crucial cooperative role of arsenic trioxide and Curcumin and their ability to protect against prostate cancers by targeting the epithelial-to-mesenchymal transition and expression of apoptosis-related genes. Material and methodsThe human prostate cell lines (LNCaP and PC3) were treated with different concentrations of Curcumin and As2O3 alone and combined to find effective doses and IC50 values. Percentages of apoptotic cells were evaluated by Annexin/P.I. staining, the proliferative inhibitory effect was assessed by Micro Culture Tetrazolium Test (MTT), and mRNA levels of KLK2, E-cadherin, SNAIL, angiogenesis genes (VEGFA and VEGFC), and apoptosis genes (BAX, Bcl2, and P53) expression were investigated by the real-time PCR method. ANOVA and t-test were used to appraise the results. ResultsFor the first time, we presented that the combination therapy of Curcumin and As2O3 increases prostate cancer cell apoptosis and inhibits proliferation; Our data displayed that Curcumin (15 μM and 10 μM in PC3 and LNCap), As2O3 (8 μM and 5 μM in PC3 and LNCap), and also their combination (15 μM Curcumin and 8 μM As2O3 in PC3, 10 μM Curcumin and 5 μM As2O3 in LNCap cell lines) significantly increased the percentage of apoptotic cells and inhibited cell growth (P < 0.05) compared with each drug alone. Generally, both cell lines treated with the combination of Curcumin and As2O3 displayed decreased angiogenesis genes (VEGFA and VEGFC), apoptosis genes (BAX and Bcl2), and prostate cancer marker (KLK2), the zinc-finger protein (SNAIL); and an increase in expression (P < 0.05) of cell–cell adhesion molecule (E-cadherin) and tumor suppressor gene (P53) genes. ConclusionsThe antitumor effects of combination therapy with As2O3 and Curcumin have been displayed on prostate cancer cell lines (LNCaP and PC3), which probably originates from their potential to induce apoptosis and inhibit the growth of prostate cancer cells simultaneously.

Expression of icaA, B, D, R and ebps biofilm-associated genes in methicillin-resistant-Staphylococcus aureus in exposure to curcumin

BackgroundBiofilm formation is a paramount event to develop withstanding and sustainable biofilms by bacterial species. Methicillin-resistant Staphylococcus aureus (S. aureus, MRSA) causes a variety of infections. Our aim was evaluation of effect of curcumin compound on the expression of icaA, B, D, R and ebps genes related to biofilm formation among MRSA from blood samples. MethodsOne-hundred MRSA were collected from blood samples. Various concentrations of curcumin were assessed for antimicrobial effect including 1, 2, 5, 10 and 20 mg/mL in 96-well plates and incubated for 24 h. Curcumin at concentration of 2 mg/mL was prepared and exposed to bacterial culture (with a suspension equal to 0.5 Mac Farland) and incubated for 24 h. The expression of icaA, B, R and ebps genes related to biofilm formation was measured in exposure to 2 mg/mL of curcumin using real-time PCR method. ResultsPrevious hospitalization (58%, p = 0.0372) and antibiotic consumption (76%, p = 0.0023) were found as major risk factors of MRSA isolation. The minimum inhibitory and bactericidal concentrations (MIC and MBC, respectively) of curcumin ranged 5–10 and 10- > 20 mg/mL, respectively. The curcumin exerted a significantly higher anti-biofilm effect at concentrations 5, 10 and 20 mg/mL compared to the control group. The expression of icaA, B, D and ebps genes decreased 1.8 fold (p = 0.011), 2 fold (p = 0.002), 2.3 fold (p < 0.001) and 3 fold (p < 0.001), respectively which was significant, but the expression of the icaR was not significantly decreased (0.3 fold, p = 0.339). ConclusionThe curcumin compound had antimicrobial effect against MRSA. The expression of biofilm-associated genes was decreased in exposure to sub-MIC concentration of curcumin. Therefore, curcumin has the potential of application as an alternative antimicrobial agent.

Keto-enol tautomerism of curcumin in the preparation of nanobiocomposites with fumed silica

The tautomerism of curcumin (Cur) in water–ethanol solutions in the presence of fumed silica was studied by UV–visible spectroscopy. The results showed that the enol tautomer exists at an ethanol concentration in solution >50%, and with an increase in the water content, the tautomeric equilibrium shifts towards the formation of the keto tautomer. Quantum-chemical calculations (solvation model SM 5.42/6-31G (d), GAMESSPLUS) of various curcumin isomers confirmed that the existence of curcumin keto tautomer in aqueous solution is more thermodynamically favorable. The ratio of keto and enol forms also depends on the dielectric constant of water–ethanol solutions: at ε < 45, only the enol form of curcumin exists, while at ε > 45, the relative amount of the keto tautomer increases in proportion to the dielectric constant. Curcumin tautomers adsorb on fumed silica in different ways. At a low curcumin concentration in the initial solutions (<1.5 × 10−4 M), only the enol tautomer forms a monolayer on the sorbent surface, apparently due to its planar structure. The keto tautomer, characterized by a bent structure, begins to adsorb only at a concentration of Cur > 1.5 × 10−4 M, being a component of molecular aggregates with coplanar geometry.

Inactivation of Bacillus subtilis by Curcumin-Mediated Photodynamic Technology through Inducing Oxidative Stress Response.

Photodynamic sterilization technology (PDT) is widely used in disease therapy, but its application in the food industry is still at the research stage because of the limitations of food-grade photosensitizers. Curcumin exhibits photosensitivity and is widely used as a food additive for its natural color. This study aimed to determine the effect of curcumin-mediated photodynamic technology (Cur-PDT) on Bacillus subtilis and to elucidate the anti-bacterial mechanism involved. First, the effects of curcumin concentration, duration of light irradiation, light intensity, and incubation time on the inactivation of B. subtilis were analyzed. It was found that Cur-PDT inactivated 100% planktonic cells with 50 μmol/L curcumin in 15 min (120 W). Then, the cell morphology, oxidation state and the expression of membrane structure- and DNA damage-related genes of B. subtilis vegetative cells were investigated under different treatment conditions. The membrane permeability of cells was enhanced and the cell membrane structure was damaged upon treatment with Cur-PDT, which were exacerbated with increases of treatment time and curcumin concentration. Meanwhile, the production of reactive oxygen species increased and the activities of the antioxidant enzymes SOD, GPX, and CAT decreased inside the cells. Furthermore, the Cur-PDT treatment significantly downregulated the mRNA of the membrane protein TasA and upregulated the DNA damage recognition protein UvrA and repair protein RecA of B. subtilis. These results suggested that curcumin-mediated PDT could effectively inactivate B. subtilis by inducing cell redox state imbalance, damaging DNA, and disrupting membrane structures.

Extraction of curcumin from turmeric by ultrasonic-assisted extraction, identification, and evaluation of the biological activity

Introduction: Dried rhizomes of turmeric have been traditionally used as a medicinal herb, dietary spice, food source, food preservative, and natural coloring agent in many Asian countries. This study aimed to develop the ultrasonic-assisted extraction (UAE) method for the extraction of curcumin from turmeric powder, evaluate the extraction efficiency, curcumin concentration, and biological activities.Methods: The UAE effects were examined based on several parameters of extraction efficiencies. The curcumin content was also determined using high-performance liquid chromatography (HPLC), and the total phenolic content (TPC) was estimated by Folin-Ciocalteu colorimetric method. The antibacterial activity of the extracted was evaluated against the test pathogenic bacteria by the disc diffusion method. The correlation between extraction yield and curcumin content was performed by principal components analysis (PCA).Results: The optimal UAE conditions were: ethanol, a solid-liquid ratio of 1:10 (w/v), an extraction time of 40 min, and only one extraction step. Under the optimal conditions, the yield of curcumin was 160.3 ± 1.17 (mg/g extract) and the TPC was 185.5 ± 3.07 (mg gallic acid equivalent /g extract). PCA presented the positive correlation between curcumin and the TPC of the studied extracts. Comparison of antibacterial activity between UAE and maceration method against the tested bacteria showed no significant difference at P &gt; 0.05.Conclusion: UAE was a viable alternative as a rapid, efficient, and simple means of extraction of curcumin from turmeric. The extracts had great potential as a source of antioxidant agents with high amounts of curcuminoids, phenolic compounds and exhibited activity against pathogenic bacteria.

Mechanism Study on Radiosensitization Effect of Curcumin in Bladder Cancer Cells Regulated by Filamin A.

ObjectiveTo study the radiosensitization effect of curcumin, a natural product with anti-inflammatory and anti-cancer properties, in bladder cancer cells and identify the specific role of FLNA gene in that process.MethodsCCK-8 method was initially adopted to identify the proper interventional concentration of curcumin. T24 bladder cancer cells were subjected to CCK-8, flow cytometry, and colony formation assay to study the cell biological behaviors under different interventions. γ-H2AX test was performed to test the level of damage in T24 cells. RT-qPCR and Western blot were conducted to measure FLNA mRNA and protein levels.ResultsLow-dose curcumin (10, 20 μM) following X-ray exposure resulted in increased DNA damage, augmented apoptosis, and reduced proliferation of T24 cells. Certain radiosensitization was demonstrated when curcumin was applied at 10 μM. Additionally, elevation of FLNA gene and protein levels was also indicated upon combination treatment.ConclusionLow-dose curcumin has certain radiosensitization effect in bladder cancer, where FLNA plays a certain regulatory role.

On the Curcumin and β‐Cyclodextrin Interaction in Aqueous Media. Spectrophotometric and Electrochemical Study

AbstractIt is shown from UV/Vis spectrophotometry measurements, that up to two inclusion complexes between curcumin and β‐cyclodextrin, namely H3Cur(β‐CD) and H3Cur(β‐CD)2, can be formed in aqueous solution at pH=3.6, where the fully protonated and neutral species of curcumin, H3Cur, predominate depending on the β‐CD concentration. The thermodynamic formation constants of these supramolecular complexes were determined and the molar absorptivity coefficients of H3Cur, H3Cur(β‐CD) and H3Cur(β‐CD)2 species were assessed. In the absence of β‐CD, curcumin degradation increases linearly with time at a rate of 3.25 % min−1. However, in its presence, the rate drastically diminishes to 0.11 % min−1. These results were corroborated from independent electrochemical measurements using a bare carbon paste electrode. At 0.01 M β‐CD the first voltammogram cycle displayed single anodic and cathodic peaks while the second cycle is formed by two anodic peaks and one cathodic, all of them being due to single‐electron adsorption‐controlled processes. The current of these peaks can be used to quantify curcumin concentration in real samples.