Chadarat Ampasavate

Demethoxycurcumin suppresses migration and invasion of MDA-MB-231 human breast cancer cell line

Demethoxycurcumin (DMC) is one of the main active compounds of curcuminoids found in turmeric powder, which is used as a spice in Asian cooking and traditional medicine. Recent studies reveal that DMC has several biological activities including anti-inflammation and anti-cancer activities. However, the molecular mechanism by which DMC has anti-metastasis activity in breast cancer cells remains poorly understood. Here, we report for the first time that DMC inhibited adhesion, migration and invasion of MDA-MB-231 human breast cancer cells. For cancer cell migration and invasion, extracellular matrix (ECM) degradation processes are required. MDA-MB-231 cells treated with DMC had decreased levels of ECM degradation-associated proteins including matrix metalloproteinase-9 (MMP-9), membrane type-1 matrix metalloproteinase (MT1-MMP), urokinase plasminogen activator (uPA) and uPA receptor (uPAR), while the level of uPA inhibitor (PAI-1) was up-regulated. Moreover, DMC also reduced the expression of intercellular adhesion molecule-1 (ICAM-1) and chemokine receptor 4, (CXCR4), which is involved in modulation of the tumor metastasis process. We also found that DMC treatment inhibited the DNA binding activity of nuclear factor-kappa B (NF-kappaB), which is known to mediate the expression of MMPs, uPA, uPAR, ICAM-1, and CXCR4. These findings strongly suggest that the mechanism of DMC-mediated anti-invasive activity involves modulation of the expression of invasion-associated proteins, possibly by targeting NF-kappaB in MDA-MB-231 cells.

Enhancement of cellular uptake and cytotoxicity of curcumin-loaded PLGA nanoparticles by conjugation with anti-P-glycoprotein in drug resistance cancer cells

Aim:To compare the anti-cancer activity and cellular uptake of curcumin (Cur) delivered by targeted and non-targeted drug delivery systems in multidrug-resistant cervical cancer cells.Methods:Cur was entrapped into poly (DL-lactide-co-glycolide) (PLGA) nanoparticles (Cur-NPs) in the presence of modified-pluronic F127 stabilizer using nano-precipitation technique. On the surface of Cur-NPs, the carboxy-terminal of modified pluronic F127 was conjugated to the amino-terminal of anti-P-glycoprotein (P-gp) (Cur-NPs-APgp). The physical properties of the Cur-NPs, including particle size, zeta potential, particle morphology and Cur release kinetics, were investigated. Cellular uptake and specificity of the Cur-NPs and Cur-NPs-APgp were detected in cervical cancer cell lines KB-V1 (higher expression of P-gp) and KB-3-1 (lower expression of P-gp) using fluorescence microscope and flow cytometry, respectively. Cytotoxicity of the Cur-NPs and Cur-NPs-APgp was determined using MTT assay.Results:The particle size of Cur-NPs and Cur-NPs-APgp was 127 and 132 nm, respectively. The entrapment efficiency and actual loading of Cur-NPs-APgp (60% and 5 μg Cur/mg NP) were lower than those of Cur-NPs (99% and 7 μg Cur/mg NP). The specific binding of Cur-NPs-APgp to KB-V1 cells was significantly higher than that to KB-3-1 cells. Cellular uptake of Cur-NPs-APgp into KB-V1 cells was higher, as compared to KB-3-1 cells. However, the cellular uptake of Cur-NPs and Cur-NPs-IgG did not differ between the two types of cells. Besides, the cytotoxicity of Cur-NPs-APgp in KB-V1 cells was higher than those of Cur and Cur-NPs.Conclusion:The results demonstrate that Cur-NPs-APgp targeted to P-gp on the cell surface membrane of KB-V1 cells, thus enhancing the cellular uptake and cytotoxicity of Cur.

Investigation of fruit peel extracts as sources for compounds with antioxidant and antiproliferative activities against human cell lines

The aim of this study was to evaluate antioxidant activity and cytotoxicity against human cell lines of fruit peel extracts from rambutan, mangosteen and coconut. The highest antioxidant activity was found from rambutan peel crude extract where the highest radical scavenging capacity via ABTS assay was from its ethyl acetate fraction with a TEAC value of 23.0mM/mg and the highest ferric ion reduction activity via FRAP assay was from its methanol fraction with an EC value of 20.2mM/mg. Importantly, using both assays, these fractions had a higher antioxidant activity than butylated hydroxyl toluene and vitamin E. It was shown that the ethyl acetate fraction of rambutan peel had the highest polyphenolic content with a gallic acid equivalent of 2.3mg/mL. The results indicate that the polyphenolic compounds are responsible for the observed antioxidant activity of the extracts. Interestingly, the hexane fraction of coconut peel showed a potent cytotoxic effect on KB cell line by MTT assay (IC(50)=7.7 microg/mL), and no detectable cytotoxicity toward normal cells. We concluded that the ethyl acetate fraction of rambutan peel is a promising resource for potential novel antioxidant agents whereas the hexane fraction of coconut peel may contain novel anticancer compounds.

The inhibitory effect of turmeric curcuminoids on matrix metalloproteinase-3 secretion in human invasive breast carcinoma cells

Matrix metalloproteinase-3 (MMP-3) is a key enzyme with important implications in the invasion and metastasis of breast cancer cells. Curcumin (Cur), demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) are major forms of curcuminoids found in turmeric powder with reported anticancer activity. This study focuses on the comparative effect of Cur, DMC and BDMC on the modulation of MMP-3 activity and its secretion in MDA-MB-231 breast cancer cells. MMP-3 levels were determined by casein zymography, ELISA and western blotting. Analysis of MMP-3 expression by casein zymography revealed high expression in MDA-MB-231 invasive breast carcinoma cells, but not in MCF-7 non-invasive breast cancer cells. ELISA assays showed MMP-3 levels were significantly decreased in all curcuminoid treatments. Using zymography, treatment with non-toxic doses revealed that every curcuminoid compound except Cur reduced MMP-3 levels. Moreover, the result from western blot analysis confirmed that only DMC and BDMC reduced MMP-3 secretion in MDA-MB-231 cells, but Cur did not have any effect. MMP-3 activity revealed that none of the curcuminoids showed significant effects. However, treatment of the cells with Cur, DMC and BDMC exhibited a significant inhibition of cell invasion and motility with DMC and BDMC being more potent. These results suggest that Cur, DMC, and BDMC may be used as MMP-3 inhibitors to modulate MMP-3 expression.

Stemona alkaloids, from traditional Thai medicine, increase chemosensitivity via P-glycoprotein-mediated multidrug resistance

P-glycoprotein-mediated drug efflux can cause a multidrug resistance (MDR) phenotype that is associated with a poor response to cancer chemotherapy. Through bioassay-guided fractionation, active Stemona alkaloids were isolated from the roots of Stemona aphylla and S. burkillii. The chemical structures of isolated alkaloids were confirmed by HPLC, LC-MS and NMR as stemocurtisine and oxystemokerrine from S. aphylla, and stemofoline from S. burkillii. The isolated alkaloids were evaluated for synergistic growth inhibitory effect with cancer chemotherapeutic agents including vinblastine, paclitaxel and doxorubicin of KB-V1 cells (MDR human cervical carcinoma with P-gp expression), but not in KB-3-1 cells (drug sensitive human cervical carcinoma, which lack P-gp expression). Verapamil was employed as a comparative agent. The results showed that among these three isolated alkaloids; stemofoline exhibited the most potent effect in vitro in the reversal of P-gp-mediated MDR. Treatment with stemofoline at the various concentrations up to 72 h was able to significantly increase sensitivity of anticancer drugs including vinblastine, paclitaxel and doxorubicin in dose- and time-dependent manner in KB-V1 cells. The result obtained from this study indicated that Stemona alkaloids may play an important role as a P-gp modulator as used in vitro and may be effective in the treatment of multidrug-resistant cancers. This is the first report of new pharmacological activity of Stemona alkaloids, which could be a new potential MDR chemosensitizer.

Anti-P-glycoprotein conjugated nanoparticles for targeting drug delivery in cancer treatment

Targeting therapeutics to specific sites can enhance the efficacy of drugs, reduce required doses as well as unwanted side effects. In this work, using the advantages of the specific affinity of an immobilized antibody to membrane P-gp in two different nanoparticle formulations were thus developed for targeted drug delivery to multi-drug resistant cervical carcinoma (KB-V1) cells. Further, this was compared to the human drug sensitive cervical carcinoma cell line (KB-3-1) cells. The two nanoparticle preparations were: NP1, anti-P-gp conjugated with poly (DL-lactic-coglycolic acid) (PLGA) nanoparticle and polyethylene glycol (PEG); NP2, anti-P-gp conjugated to a modified poloxamer on PLGA nanoparticles. The cellular uptake capacity of nanoparticles was confirmed by fluorescent microscopy. Comparing with each counterpart core particles, there was a higher fluorescence intensity of the targeted nanoparticles in KBV1 cells compared to KB-3-1 cells suggesting that the targeted nanoparticles were internalized into KB-V1 cells to a greater extent than KB-3-1 cell. The results had confirmed the specificity and the potential of the developed targeted delivery system for overcoming multi-drug resistance induced by overexpression of P-gp on the cell membrane.

Stable curcumin-loaded polymeric micellar formulation for enhancing cellular uptake and cytotoxicity to FLT3 overexpressing EoL-1 leukemic cells.

&NA; The present study aims to develop a stable polymeric micellar formulation of curcumin (CM) with improved solubility and stability, and that is suitable for clinical applications in leukemia patients. CM‐loaded polymeric micelles (CM‐micelles) were prepared using poloxamers. The chemical structure of the polymers influenced micellar properties. The best formulation of CM‐micelles, namely CM‐P407, was obtained from poloxamer 407 at drug to polymer ratio of 1:30 and rehydrated with phosphate buffer solution pH 7.4. CM‐P407 exhibited the smallest size of 30.3 ± 1.3 nm and highest entrapment efficiency of 88.4 ± 4.1%. When stored at −80 °C for 60 days, CM‐P407 retained high protection of CM and had no significant size change. In comparison with CM solution in dimethyl sulfoxide (CM‐DMSO), CM kinetic degradation in both formulations followed a pseudo‐first‐order reaction, but the half‐life of CM in CM‐P407 was approx. 200 times longer than in CM‐DMSO. Regarding the activity against FLT3 overexpressing EoL‐1 leukemic cells, CM‐P407 showed higher cytotoxicity than CM‐DMSO. Moreover, intracellular uptake to leukemic cells of CM‐P407 was 2–3 times greater than that of CM‐DMSO. These promising results for CM‐P407 will be further investigated in rodents and in clinical studies for leukemia treatment. Graphical abstract Figure. No caption available.

Inhibitory effect of turmeric curcuminoids on FLT3 expression and cell cycle arrest in the FLT3-overexpressing EoL-1 leukemic cell line.

Leukemia is a hematologic malignancy with a frequent incidence and high mortality rate. Previous studies have shown that the FLT3 gene is overexpressed in leukemic blast cells, especially in acute myeloid leukemia. In this study, a commercially available curcuminoid mixture (1), pure curcumin (2), pure demethoxycurcumin (3), and pure bisdemethoxycurcumin (4) were investigated for their inhibitory effects on cell growth, FLT3 expression, and cell cycle progression in an FLT3-overexpressing EoL-1 leukemic cell line using an MTT assay, Western blotting, and flow cytometry, respectively. The mixture (1) and compounds 2-4 demonstrated cytotoxic effects with IC50 values ranging from 6.5 to 22.5 μM. A significant decrease in FLT3 protein levels was found after curcuminoid treatment with IC20 doses, especially with mixture 1 and compound 2. In addition, mixture 1 and curcumin (2) showed activity on cell cycle arrest at the G0/G1 phase and decreased the FLT3 and STAT5A protein levels in a dose-dependent manner. Compound 2 demonstrated the greatest potential for inhibiting cell growth, cell cycle progression, and FLT3 expression in EoL-1 cells. This investigation has provided new findings regarding the effect of turmeric curcuminoids on FLT3 expression in leukemic cells.

Development and Characterization of FLT3-Specific Curcumin-Loaded Polymeric Micelles as a Drug Delivery System for Treating FLT3-Overexpressing Leukemic Cells

This study aimed at developing a curcumin (CM) nanoparticle targeted to Feline McDonough Sarcoma (FMS)-like tyrosine kinase 3 (FLT3) protein on the surface of leukemic cells and at evaluating their properties, specificity, cytotoxicity, and inhibitory effect on FLT3 protein level in FLT3-overexpressing leukemic cells, EoL-1, and MV-4-11 cells. FLT3-specific peptides were conjugated onto modified poloxamer 407 using the copper-catalyzed azide-alkyne cycloaddition reaction. The thin film hydration method was performed for FLT3-specific CM-loaded polymeric micelles (FLT3-CM-micelles) preparation. Flow cytometry and fluorescence microscopy were used to determine rate of cellular uptake. 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to test the cytotoxicity of the micelles on leukemic cells. FLT3-CM-micelles demonstrated a mean particle size less than 50 nm, high entrapment efficiency, and high rate of CM uptake by leukemic cells. The intracellular CM fluorescence is related to FLT3 protein levels on the leukemic cell surfaces. Moreover, FLT3-CM-micelles demonstrated an excellent cytotoxic effect and decreased FLT3 protein expression in the leukemic cells. The FLT3-CM-micelles could enhance both solubility and cytotoxicity of CM on FLT3-overexpressing leukemic cells. These promising nanoparticles may be used for enhancing antileukemic activity of CM and developed as a targeted drug delivery system in the future.

Down-regulatory mechanism of mammea E/BB from Mammea siamensis seed extract on Wilms' Tumor 1 expression in K562 cells

BackgroundWilms’ tumor 1 (WT1) is a biological marker for predicting leukemia progression. In this study, mammea E/BB, an active compound from Saraphi (Mammea siamensis) seed extract was examined for its effect on down-regulatory mechanism of WT1 gene expression, WT1 protein and mRNA stability, and cell proliferation in K562 cell line.MethodsM. siamensis seeds were obtained from the region of Chiang Mai (North of Thailand). Mammea E/BB was extracted from seeds of M. siamensis. WT1 protein expression and stability were evaluated by Western blot analysis. WT1 mRNA stability was assessed by qRT-PCR. WT1-DNA binding and WT1 promoter activity were assayed by ChIP assay and luciferase-reporter assay, respectively. Cell cycle arrest was studied by flow cytometry.ResultsTreatment with mammea E/BB led to down-regulation of WT1 expression. The suppression of WT1 expression did not involve protein and mRNA degradation. Rather, WT1 protein was down-regulated through disruption of transcriptional auto-regulation of the WT1 gene. Mammea E/BB inhibited WT1-DNA binding at the WT1 promoter and decreased luciferase activity. It also disrupted c-Fos/AP-1 binding to the WT1 promoter via ERK1/2 signaling pathway and induced S phase cell cycle arrest in K562 cells.ConclusionMammea E/BB had pleotropic effects on kinase signaling pathways, resulting in inhibition of leukemia cell proliferation.