Combined xanthorrhizol-curcumin exhibits synergistic growth inhibitory activity via apoptosis induction in human breast cancer cells MDA-MB-231

Essential oils and their nanoformulations for breast cancer therapy

Breast Cancer (BC) is the most prevalent type of cancer in the world. Current treatments include surgery, radiation, and chemotherapy but often are associated with high toxicity to normal tissues, chemoresistance, and relapse. Thus, developing novel therapies which could combat these limitations is essential for effective treatment. In this context, phytochemicals are increasingly getting popular due to their safety profile, ability to efficiently target tumors, and circumvent limitations of existing treatments. Essential Oils (EOs) are mixtures of various phytochemicals which have shown potential anticancer activity in preclinical BC models. However, their clinical translation is limited by factors such as high volatility, low stability, and poor solubility. Nanotechnology has facilitated their encapsulation in a variety of nanostructures and proven to overcome these limitations. In this review, we have efficiently summarized the current knowledge on the anticancer effect of EOs and constituents in both in in vitro and in in vivo BC models. Further, we also provide a descriptive account on the potential of nanotechnology in enhancing the anti-BC activity of EOs and their constituents. The papers discussed in this review were selected using the keywords "antiproliferative Essential Oils in breast cancer," "anticancer activity of Essential Oil in breast cancer," and "cytotoxicity of Essential Oils in breast cancer" performed in PubMed and ScienceDirect databases.

Anti-biofilm activity of a novel nanoemulsion containing Curcuma xanthorrhiza oil

OBJECTIVES

We aimed to solubilize Curcuma xanthorrhiza oil (CXO) using nanoemulsification and evaluate its inhibitory effects against biofilm formation.

METHODS

The components of CXO were evaluated through high-performance liquid chromatography (HPLC) analysis. Healthy human saliva was inoculated onto hydroxyapatite discs to form microcosm biofilms for four days and treated six times with each antimicrobial agent: distilled water (DW), CXO emulsion (EM), CXO nanoemulsion (NE), and positive controls (Listerine and chlorhexidine). Biofilm fluorescence imaging was performed using quantitative light-induced fluorescence, and cell viability and dry-weight measurements were obtained. We compared the bacterial cell and extracellular polysaccharide (EPS) biovolume and thickness using confocal laser scanning microscopy (CLSM).

RESULTS

HPLC analysis revealed that CXO was composed of approximately 47% xanthorrhizol. Compared with DW, NE exhibited significantly lower red fluorescence intensity and area (42% and 37%, p < 0.001 and p < 0.001, respectively), and reduced total and aciduric bacterial cell viability (7.3% and 3.9%, p < 0.001, p = 0.01, respectively). Furthermore, the bacterial cell and EPS biovolume and thickness in NE decreased by 40-80% compared to DW, similar to chlorhexidine. Conversely, EM showed a significant difference only in cell viability against total bacteria when compared with DW (p = 0.003), with EPS biovolume and thickness exhibiting higher values than DW.

CONCLUSIONS

Nanoemulsification successfully solubilized CXO and demonstrated superior anti-biofilm effects compared to the emulsion form.

CLINICAL SIGNIFICANCE

These findings suggest the potential use of NE as a novel antimicrobial agent for preventing oral diseases.

Xanthorrhizol, a potential anticancer agent, from Curcuma xanthorrhiza Roxb

BACKGROUND

Xanthorrhizol (XTZ), a bisabolene sesquiterpenoid, is abundantly found in the plant Curcuma xanthorrhiza Roxb. Traditionally, C. xanthorrhiza is widely used for the treatment of different health conditions, including common fever, infection, lack of appetite, fatigue, liver complaints, and gastrointestinal disorders. XTZ exhibits wide-ranging pharmacological activities, including anticancer, antioxidative, anti-inflammatory, antimicrobial, and antidiabetic activities, in addition to a protective effect on multiple organs. The present review provides detailed findings on the anticancer activities of XTZ and the underlying cellular and molecular mechanisms.

METHODS

Literature was searched systematically in main databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, with keywords "tumor AND xanthorrhizol" or "cancer AND xanthorrhizol".

RESULTS

Studies show that XTZ has preventive and therapeutic activities against different types of cancer, including breast, cervical, colon, liver, lung, oral and esophageal, and skin cancers. XTZ regulates multiple signaling pathways that block carcinogenesis and proliferation. In vitro and in vivo studies showed that XTZ targets different kinases, inflammatory cytokines, apoptosis proteins, and transcription factors, leading to the suppression of angiogenesis, metastasis, and the activation of apoptosis and cell cycle arrest.

CONCLUSION

The potential anticancer benefits of XTZ recommend further in vivo studies against different types of cancer. Further, XTZ needs to be confirmed for its toxicity, bioavailability, protective, antifatigue, and energy booster activities. Future studies for the therapeutic development of XTZ may be directed to cancer-related fatigue.

Javanese Turmeric (Curcuma xanthorrhiza Roxb.): Ethnobotany, Phytochemistry, Biotechnology, and Pharmacological Activities

Curcuma xanthorrhiza Roxb., locally famed as Temulawak, has been extensively utilized in Indonesia as medicinal and nutritional plants since immemorial time. The rhizome of this plant is an important ingredient for jamu formulation (Indonesian traditional medicine). C. xanthorrhiza is traditionally used to treat several ailments such as lack of appetite, stomach disorder, liver illness, constipation, bloody diarrhea, dysentery, arthritis, children's fevers, hypotriglyceridaemia, hemorrhoids, vaginal discharge, rheumatism, and skin eruptions. To date, over 40 active compounds, including terpenoids, curcuminoids, and other phenolic compounds, have been isolated and identified from C. xanthorrhiza Roxb. Some pharmacological tests reported that C. xanthorrhiza Roxb. has antioxidant, antimicrobial, anti-inflammatory, anticancer and antitumor, antidiabetic, and skincare and hepatoprotective properties. Efforts for biotechnologically production of C. xanthorrhiza have also been conducted, resulting in some micropropagation protocols of this plant. The current review focuses on the botanical description and distribution, ethnomedicinal uses, production and conservation status, phytochemical properties, and pharmacological activities of C. xanthorrhiza Roxb. to provide accurate and reliable data for future researches and commercialization purposes.

Comprehensive computational target fishing approach to identify Xanthorrhizol putative targets

Xanthorrhizol (XNT), is a bioactive compound found in Curcuma xanthorrhiza Roxb. This study aimed to determine the potential targets of the XNT via computational target fishing method. This compound obeyed Lipinski's and Veber's rules where it has a molecular weight (MW) of 218.37 gmol^-1, TPSA of 20.23, rotatable bonds (RBN) of 4, hydrogen acceptor and donor ability is 1 respectively. Besides, it also has half-life (HL) values 3.5 h, drug-likeness (DL) value of 0.07, oral bioavailability (OB) of 32.10, and blood-brain barrier permeability (BBB) value of 1.64 indicating its potential as therapeutic drug. Further, 20 potential targets were screened out through PharmMapper and DRAR-CPI servers. Co-expression results derived from GeneMANIA revealed that these targets made connection with a total of 40 genes and have 744 different links. Four genes which were RXRA, RBP4, HSD11B1 and AKR1C1 showed remarkable co-expression and predominantly involved in steroid metabolic process. Furthermore, among these 20 genes, 13 highly expressed genes associated with xenobiotics by cytochrome P450, chemical carcinogenesis and steroid metabolic pathways were identified through gene ontology (GO) and KEGG pathway analysis. In conclusion, XNT is targeting multiple proteins and pathways which may be exploited to shape a network that exerts systematic pharmacological effects.

Enhancing Bioavailability and Stability of Curcumin Using Solid Lipid Nanoparticles (CLEN): A Covenant for Its Effectiveness

Curcumin, very rightly referred to as "a wonder drug" is proven to be efficacious in a variety of inflammatory disorders including cancers. Antiaging, anti-inflammatory, antioxidant, antitumor, chemosensitizing, P-gp efflux inhibiting, and antiproliferative activity are some of the striking features of curcumin, highlighting its importance in chemotherapy. Curcumin inhibits Bcl-2, Bcl-XL, VEGF, c-Myc, ICAM-1, EGFR, STAT3 phosphorylation, and cyclin D1 genes involved in the various stages of breast, prostate, and gastric cancer proliferation, angiogenesis, invasion, and metastasis. The full therapeutic potential of curcumin however remains under explored mainly due to poor absorption, rapid metabolism and systemic elimination culminating in its poor bioavailability. Furthermore, curcumin is insoluble, unstable at various pH and is also prone to undergo photodegradation. Nanotechnology can help improve the therapeutic potential of drug molecules with compromised biopharmaceutical profiles. Solid lipid nanoparticles (SLNs) are the latest offshoot of nanomedicine with proven advantages of high drug payload, longer shelf life, biocompatibility and biodegradability, and industrial amenability of the production process. We successfully developed CLEN (Curcumin encapsulated lipidic nanoconstructs) containing 15 mg curcumin per ml of the SLN dispersion with highest (till date, to our knowledge) increase in solubility of curcumin in an aqueous system by 1.4 × 106 times as compared to its intrinsic solubility of 11 ng/ml and high drug loading (15% w/v with respect to lipid matrix). Zero-order release kinetics observed for CLEN versus first order release for free curcumin establish controlled release nature of the developed CLEN. It showed 69.78 times higher oral bioavailability with respect to free curcumin; 9.00 times higher than a bioavailable marketed formulation (CurcuWIN®). The formulation showed 104, 13.3, and 10-times enhanced stability at pH 6.8, 1.2, and 7.4, respectively. All these factors ensure the efficacy of CLEN in treating cancer and other inflammatory diseases.

Synergistic Impact of Xanthorrhizol and d-δ-Tocotrienol on the Proliferation of Murine B16 Melanoma Cells and Human DU145 Prostate Carcinoma Cells

Isoprenoids suppress the mevalonate pathway that provides prenyl groups for the posttranslational modification of growth-regulating proteins. We hypothesize that xanthorrhizol and d-δ-tocotrienol synergistically suppress the growth of murine B16 melanoma and human DU145 prostate carcinoma cells. Xanthorrhizol (0-200 µmol/L; half maximal inhibitory concentration [IC₅₀] = 65 µmol/L) and d-δ-tocotrienol (0-40 µmol/L; IC₅₀ = 20 µmol/L) each induced a concentration-dependent suppression of the proliferation of B16 cells and concurrent cell cycle arrest at the G1 phase. A blend of 16.25 µmol/L xanthorrhizol and 10 µmol/L d-δ-tocotrienol suppressed B16 cell proliferation by 69%, an impact greater than the sum of those induced by xanthorrhizol (15%) and d-δ-tocotrienol (12%) individually. The blend cumulatively reduced the levels of cyclin-dependent kinase four and cyclin D1, key regulators of cell cycle progression at the G1 phase. The expression of RAS and extracellular signal-regulated kinase (ERK1/2) in the proliferation-stimulating RAS-RAF-MEK-ERK pathway was downregulated by the blend. Xanthorrhizol also induced a concentration-dependent suppression of the proliferation of DU145 cells with concomitant morphological changes. Isobologram confirmed the synergistic effect of xanthorrhizol and d-δ-tocotrienol on DU145 cell proliferation with combination index values ranging 0.61-0.94. Novel combinations of isoprenoids with synergistic actions may offer effective approaches in cancer prevention and therapy.

Synergistic efficacy of RLIP inhibition and 2'-hydroxyflavanone against DMBA-induced mammary carcinogenesis in SENCAR mice

Substantial evidence suggests that 7,12-dimethylbenzanthracene (DMBA)-induced mammary carcinogenesis in mice mimics human breast cancer (BC) in many respects. Therefore, it has been used extensively to evaluate preventive and therapeutic agents for human BC. Mammary carcinogenesis induced by DMBA administration in female SENsitive to CARcinogen (SENCAR) mice was characterized by histopathological analysis of the mammary glands and alterations to the phosphatidylinositol 3-kinase/protein kinase B/cyclin-dependent kinase 1 (PI3K/Akt/CDK1) pathway. We recently reported that 2'-hydroxyflavanone (2HF) is a promising diet-derived chemotherapeutic agent that suppresses BC growth in vitro and in vivo by targeting a 76 kDa ral-interacting protein (RLIP). The objective of the current study was to investigate the synergistic anticarcinogenic effects of RLIP inhibition/depletion and 2HF in an in vivo model of DMBA-induced mammary carcinogenesis in SENCAR mice. Mice were given 2HF (50 mg/kg, bw, orally on alternate days), RLIP antibody (Rab; 5 mg/kg, bw, ip weekly), RLIP antisense (RAS; 5 mg/kg, b.w., ip weekly), or a combination of 2HF + Rab + RAS. Animals were monitored daily, and 7 days after the first appearance of moribund behavior, tissues were harvested for morphological and immunohistological analysis. Western blot analyses were performed to determine the expression of anti- and proapoptotic proteins in the mammary glands. Our results reveal that 2HF, RAS, and Rab significantly prevented the carcinogenic effects of DMBA administration in the mammary glands and other organs. Further, mice treated with a combination of 2HF + RAS + Rab exhibited no carcinogenic effect of DMBA as compared to either or the single agent-treated mice. This study demonstrates for the first time the anticarcinogenic effects of 2HF and RLIP inhibition/depletion in vivo in a novel DMBA-induced model of BC in SENCAR mice and provides the rationale for further clinical investigation.

Cytostatic and Antiproliferative Activities of F5 Fraction of Crinum amabile Leaf Chloroform Extract Showed Its Potential as Cancer Chemotherapeutic Agent

Medicinal plants have been considered as promising sources of drugs in treating various cancers. Crinum amabile (C. amabile), a plant species from the Amaryllidaceae family, is claimed to be a potential source for cancer chemotherapeutic compounds. Here, we aimed to investigate the potential of C. amabile as an anticancer agent. Dried leaves of C. amabile were serially extracted and our findings showed that chloroform extract (CE) was shown to exhibit cytotoxic effect against all cancer cell lines used. This active extract was further fractionated in which F5 fraction was shown to possess the highest cytotoxicity among all fractions. F5 fraction was then tested in-depth through Annexin V/FITC apoptosis and DNA fragmentation assays to determine its apoptotic effect on MCF-7 cells. Results revealed that F5 fraction only showed induction of cell apoptosis starting at 72-hour treatment while DNA fragmentation was not detected at any of the concentrations and treatment periods tested. Meanwhile, cell proliferation assay revealed that F5 fraction was able to inhibit normal cell proliferation as well as VEGF-induced cell proliferation of normal endothelial cell (HUVECs). In conclusion, F5 fraction from C. amabile leaf CE was able to exhibit cytostatic effect through antiproliferation activity rather than induction of cell apoptosis and therefore has the potential to be further investigated as an anticancer agent.

Photoactivated [Mn(CO)3Br(μ-bpcpd)]2 induces apoptosis in cancer cells via intrinsic pathway

Carbon monoxide releasing molecules (CORMs) are organometallic/organic compounds that release carbon monoxide (CO) spontaneously or upon activation. PhotoCORMs are capable of releasing CO on light based activation. This group of molecules is used in photodynamic therapy due to their ability to release CO in a controlled manner. In the present investigation, the release of CO from [Mn(CO)₃Br(μ-bpcpd)]₂ (MnCORM) upon irradiation at λ_max 365 nm was assessed spectrophotometrically using myoglobin assay and confirmed by liquid FT-IR spectroscopic analysis. Further, the cytotoxic potential of MnCORM on normal cells (HEK 293) and cancer cell lines such as lung (A549), cervical (HeLa), breast (MDA MB-231) and colon (HCT-15) was evaluated. The IC₅₀ values of MnCORM were found to be 21.37 ± 1.72, 24.12 ± 1.03, 21.89 ± 0.59 and 13.69 ± 0.91 μM on cervical (HeLa), lung (A549), colon (HCT-15) and breast (MDA MB-231) cancer cells respectively. An inquest into the nature of cell death was confirmed based on the nuclear and cytological examinations, flow cytometric analyses and protein expression studies. The AO/EB dual staining and cytological evaluation of the treated cells revealed that the cell death might be due to apoptosis. The flow cytometric analysis of propidium iodide (PI) stained cells showed a significant amount of sub-G1 hypodiploid cells due to MnCORM treatment. The MnCORM-induced apoptosis was mediated through the generation of reactive oxygen species (ROS), specifically superoxide radicals leading to loss of mitochondrial membrane potential. The intrinsic pathway of apoptosis was elucidated based on the expression studies of pro-apoptotic and apoptotic proteins such as bcl-2, bax, cyt c, cleaved caspase-3, cleaved caspase-9 and cleaved PARP. Due to its innate potential to release CO upon photoactivation and its ability to induce apoptosis via intrinsic pathway, the MnCORM molecule could be exploited for controlled release and photodynamic cancer therapy.

Evaluation of the PEG Density in the PEGylated Chitosan Nanoparticles as a Drug Carrier for Curcumin and Mitoxantrone

Polyethylene glycolated (PEGylated)curcumin-grafted-chitosan (PCC) conjugates were synthesized with three PEG/chitosan feed molar ratios (1/5, 1/7.5, and 1/10), namely PCC1, PCC2 and PCC3. Chemical structures of these conjugates were characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (¹H NMR). The degrees of substitution (DS) of PEG were 0.75%, 0.45% and 0.33%, respectively, for PCC1, PCC2 and PCC3by ¹H NMR analysis. Self-assembled PCC nanoparticles (NPs) were spherical as observed in transmission electron microscope images. Mitoxantrone (MTO)-loaded PCC NPs were prepared to analyze the particle size, zeta potential, drug loading, drug release and in vitro cytotoxicity. The MTO-loaded PCC3 NP (DS = 0.33%) possessed the smallest size (~183.1 nm), highest zeta potential (~+34.0 mV) and the largest loading capacity of curcumin (CUR, ~16.1%) and MTO (~8.30%). The release results showed that MTO-loaded PCC3 NP demonstrated the lowest percentage of MTO release and increased as pH decreased, but the CUR release could only be detected at pH 4.0. In the cytotoxicity study, MTO-loaded PCC3 NP displayed the highest cytotoxicity in HepG2 cell line and the best synergistic effect among the tested NPs. Our results suggest that the DS of PEG has impacts on the structures and functions of PCC NPs: the smaller DS of PEG was associated with the smaller size, the higher zeta potential, the slower drug release, and the higher cytotoxicity of NPs.

Antibacterial photodynamic therapy with curcumin and Curcuma xanthorrhiza extract against Streptococcus mutans

BACKGROUND

Bacteria are becoming increasingly resistant to conventional antibacterial chemotherapy. This has prompted the application of antibacterial photodynamic therapy (aPDT) in bacteria-related diseases due to its excellent biocide effects. However, few studies have attempted to develop a novel photosensitizer based on natural components. The aim of the present study was to compare the aPDT effects of curcumin and Curcuma xanthorrhiza extract (CXE) against Streptococcus mutans.

METHODS

A planktonic suspension containing an S. mutans strain was treated in three separate groups: aPDT with curcumin, CXE, and a mixture of curcumin and CXE (ratio= 1:1) at concentrations of 0, 10, 10², 10³, and 10⁴ng/ml. Light irradiation with a center wavelength of 405nm was applied using an LED (power density of 84.5mW for 300s at an energy density of 25.3J/cm²). The phototoxicity of photosensitizers against S. mutans was investigated using a colony-forming-unit assay. Percentage logarithmic reductions [log₁₀(CFU/ml) values] were analyzed using one-way ANOVA followed by the Tukey test (p<0.05) and Student's independent t-test.

RESULTS

The viability of S. mutans in the presence of curcumin, CXE, and a mixture of these two components was substantially reduced during irradiation with 405nm light. The phototoxicity of the photosensitizer varied with its solubility and concentration.

CONCLUSION

These preliminary in vitro findings imply that combining curcumin and CXE with a 405nm LED may be a novel method of applying aPDT. This could be advantageous in preventing and treating dental caries using devices that are readily available in clinics.

Inhibition of protein kinases by anticancer DNA intercalator, 4-butylaminopyrimido[4',5':4,5]thieno(2,3-b)quinoline

Targeting protein kinases (PKs) has been a promising strategy in treating cancer, as PKs are key regulators of cell survival and proliferation. Here in this study, we studied the ability of pyrimido[4′,5′:4,5]thieno(2,3-b)quinolines (PTQ) to inhibit different PKs by performing computational docking and in vitro screening. Docking studies revealed that 4-butylaminopyrimido[4′,5′:4,5]thieno(2,3-b)quinoline (BPTQ) has a higher order of interaction with the kinase receptors than other PTQ derivatives. In vitro screening confirms that BPTQ inhibits VEGFR1 and CHK2, with the IC₅₀ values of 0.54 and 1.70 µmol/L, respectively. Further, cytotoxicity of BPTQ was measured by trypan blue assay. Treatment with BPTQ decreased the proliferation of HL-60 cells with an IC₅₀ value of 12 µmol/L and induces apoptosis, as explicated by the fall in the mitochondrial membrane potential, annexin V labeling and increased expression of caspase-3. Taken together, these data suggest that BPTQ possess ability to inhibit PKs and to induce cell death in human promyelocytic leukemia cells.

Activation of the CRABPII/RAR pathway by curcumin induces retinoic acid mediated apoptosis in retinoic acid resistant breast cancer cells

Due to the anti-proliferative and anti-apoptotic effects of retinoic acid (RA), this hormone has emerged as a target for several diseases, including cancer. However, development of retinoid resistance is a critical issue and efforts to understand the retinoid signaling pathway may identify useful biomarkers for future clinical trials. Apoptotic responses of RA are exhibited through the cellular RA-binding protein II (CRABPII)/retinoic acid receptor (RAR) signaling cascade. Delivery of RA to RAR by CRABPII enhances the transcriptional activity of genes involved in cell death and cell cycle arrest. The purpose of this study was to investigate the role of curcumin in sensitizing RA-resistant triple-negative breast cancer (TNBC) cells to RA-mediated apoptosis. We provide evidence that curcumin upregulates the expression of CRABPII, RARβ and RARγ in two different TNBC cell lines. Co-treatment of the cells with curcumin and RA results in increased apoptosis as demonstrated by elevated cleavage of poly(ADP-ribose) polymerase and cleaved caspase-9. Additionally, silencing CRABPII reverses curcumin sensitization of TNBC cells to the apoptotic inducing effects of RA. These findings provide mechanistic insights into sensitizing TNBC cells to RA-mediated cell death by curcumin-induced upregulation of the CRABPII/RAR pathway.

Synergistic Effects of Chinese Herbal Medicine: A Comprehensive Review of Methodology and Current Research

Traditional Chinese medicine (TCM) is an important part of primary health care in Asian countries that has utilized complex herbal formulations (consisting 2 or more medicinal herbs) for treating diseases over thousands of years. There seems to be a general assumption that the synergistic therapeutic effects of Chinese herbal medicine (CHM) derive from the complex interactions between the multiple bioactive components within the herbs and/or herbal formulations. However, evidence to support these synergistic effects remains weak and controversial due to several reasons, including the very complex nature of CHM, misconceptions about synergy and methodological challenges to study design. In this review, we clarify the definition of synergy, identify common errors in synergy research and describe current methodological approaches to test for synergistic interaction. We discuss the strengths and weaknesses of these models in the context of CHM and summarize the current status of synergy research in CHM. Despite the availability of some scientific data to support the synergistic effects of multi-herbal and/or herb-drug combinations, the level of evidence remains low, and the clinical relevancy of most of these findings is undetermined. There remain significant challenges in the development of suitable methods for synergistic studies of complex herbal combinations.

Analysis of heterogeneity in nonspecific PEGylation reactions of biomolecules

The compositional heterogeneity associated with polymer conjugation reactions of biomolecules is analyzed for the particular case of nonspecific PEGylation reactions. It is shown that the distribution of the number of PEG moieties grafted to biomolecules such as proteins is a binomial-type function of two parameters-the reaction efficiency as well as the number of binding sites per biomolecule. The nature of this distribution implies that uniform compositions are favored for increasing number of coupling sites per biomolecule as well as for increasing efficiency of the modification process. Therefore, the binomial distribution provides a rationale for the pronounced heterogeneity that is observed for PEGylated small enzyme systems even at high coupling efficiencies. For the particular case of PEGylated trypsin it is shown that the heterogeneity results in a broad distribution of deactivation times that is captured by a stretched exponential decay model. The presented analysis is expected to apply to general modification processes of compounds in which partial functionalization of a fixed number of reactive sites is achieved by means of a nonspecific coupling reaction.

Investigation of the mechanism and apoptotic pathway induced by 4β cinnamido linked podophyllotoxins against human lung cancer cells A549

Apoptosis is essential for normal development and the maintenance of homeostasis. It plays a necessary role to protect against carcinogenesis by eliminating damaged cells. Many studies have demonstrated that the dysregulation of apoptosis results in cancer and this provides an approach to develop therapeutic agents via inducing apoptosis. In our previous studies 4β-cinnamido linked podophyllotoxin conjugates were synthesized and evaluated for their cytotoxic activity in a panel of five human cancer cell lines and the new molecules like 17a and 17f were considered as potential leads. The cytotoxic activity was comparable to etoposide. These observations prompted us to investigate the mechanism underplaying the cytotoxic activity and apoptotic pathway induced by these compounds in human lung cancer cells A459. The results of the present study revealed that these compounds exhibited DNA topoisomerase IIα inhibition and induced mitochondrial mediated apoptosis. It was further confirmed by Mitochondrial membrane potential, Cytochrome c release, cleavage of poly (ADP-ribose) polymerase (PARP), Reactive oxygen species (ROS) generation, regulation of antiapoptotic protein Bcl-2 and pro apoptotic protein Bax studied by Western blot analysis. Annexin V-FITC assay also suggested that these compounds induced cell death by apoptosis. Pretreatment with N-acetyl-L-cysteine (NAC) prevented the generation of ROS. Further, pretreatment with NAC significantly inhibited 17a and 17f induced apoptosis, suggesting that ROS are the key mediators for 17a and 17f induced apoptosis. These data indicate that these compounds might induce apoptosis in A549 cells through a ROS mediated mitochondrial dysfunction pathway. Moreover, these compounds did not significantly inhibit the noncancerous human embryonic kidney cells, HEK-293. Docking studies also elucidate the potential of these molecules to bind to the DNA topoisomerase II. Podophyllotoxin analogs were investigated for their mechanism and apoptotic pathway against lung cancer cell line, A549. These podophyllotoxin analogs inhibited DNA topoisomerase IIα and induced mitochondrial mediated apoptosis in lung cancer cell line, A549. Western blot analysis suggested that these compounds inhibited the DNA topoisomerase IIα. Studies like, Measurement of mitochondrial membrane potential (∆Ψm), Generation of intracellular reactive oxygen species (ROS) and Annexin V-FITC assay suggested that these compounds induced mitochondrial mediated apoptosis. Pretreatment with N-acetyl-L-cysteine (NAC) suggested that ROS plays a role in 17a and 17f induced apoptosis. Further the apoptotic effect of these compounds was confirmed by western blot analysis of pro apoptotic protein Bax and antiapoptotic protein Bcl-2, Cytochrome c release and cleavage of poly (ADP-ribose) polymerase (PARP). Moreover, these compounds did not significantly inhibit the noncancerous human embryonic kidney cells, HEK-293.

Cell Cycle Arrest and Induction of Apoptosis in Colon Adenocarcinoma Cells by a DNA Intercalative Quinoline Derivative, 4-Morpholinopyrimido [4',5':4,5] Selenolo (2,3-b) Quinoline

Circular dichroism, topological studies, molecular docking, absorbance, and fluorescence spectral titrations were employed to study the interaction of 4-morpholinopyrimido [4',5':4,5] selenolo (2,3-b) quinoline (MPSQ) with DNA. The association constants of MPSQ-DNA interactions were of the order of 10(4) M(-1). Melting temperature, topological, and docking studies confirmed that the mode of interaction was by intercalation with preference to d(GpC)-d(CpG) site of DNA. Cytotoxicity studies showed the MPSQ-induced dose-dependent inhibitory effect on the proliferation of different cancer cells. Colon adenocarcinoma (COLO 205) cells are more sensitive among the cell lines tested, with an IC50 value of 15 μM. Flow cytometry revealed that MPSQ affects the cell cycle progression by arresting at G2M phase. Further, Annexin V staining, mitochondrial membrane potential assay, and caspase-3 activity assay confirmed that MPSQ leads to mitochondria-mediated apoptotic cell death in COLO 205 cells.

Small molecule tolfenamic acid and dietary spice curcumin treatment enhances antiproliferative effect in pancreatic cancer cells via suppressing Sp1, disrupting NF-kB translocation to nucleus and cell cycle phase distribution

Combination of dietary/herbal spice curcumin (Cur) and COX inhibitors has been tested for improving therapeutic efficacy in pancreatic cancer (PC). The objective of this study was to identify agent with low toxicity and COX-independent mechanism to induce PC cell growth inhibition when used along with Cur. Anticancer NSAID, tolfenamic acid (TA) and Cur combination were evaluated using PC cell lines. L3.6pl and MIA PaCa-2 cells were treated with Cur (5-25μM) or TA (25-100μM) or combination of Cur (7.5μM) and TA (50μM). Cell viability was measured at 24-72h posttreatment using CellTiter-Glo kit. While both agents showed a steady/consistent effect, Cur+TA caused higher growth inhibition. Antiproliferative effect was compared with COX inhibitors, Ibuprofen and Celebrex. Cardiotoxicity was assessed using cordiomyocytes (H9C2). The expression of Sp proteins, survivin and apoptotic markers (western blot), caspase 3/7 (caspase-Glo kit), Annexin-V staining (flow cytometry), reactive oxygen species (ROS) and cell cycle phase distribution (flow cytometry) was measured. Cells were treated with TNF-α, and NF-kB translocation from cytoplasm to nucleus was evaluated (immunofluorescence). When compared to individual agents, combination of Cur+TA caused significant increase in apoptotic markers, ROS levels and inhibited NF-kB translocation to nucleus. TA caused cell cycle arrest in G0/G1, and the combination treatment showed mostly DNA synthesis phase arrest. These results suggest that combination of Cur+TA is less toxic and effectively enhance the therapeutic efficacy in PC cells via COX-independent mechanisms.

Effects of Curcuma xanthorrhiza Extracts and Their Constituents on Phase II Drug-metabolizing Enzymes Activity

Background:

Curcuma xanthorrhiza is a native Indonesian plant and traditionally utilized for a range of illness including liver damage, hypertension, diabetes, and cancer.

Objective:

The study determined the effects of C. xanthorrhiza extracts (ethanol and aqueous) and their constituents (curcumene and xanthorrhizol) on UDP-glucuronosyltransferase (UGT) and glutathione transferase (GST) activities.

Materials and Methods:

The inhibition studies were evaluated both in rat liver microsomes and in human recombinant UGT1A1 and UGT2B7 enzymes. p-nitrophenol and beetle luciferin were used as the probe substrates for UGT assay while 1-chloro-2,4-dinitrobenzene as the probe for GST assay. The concentrations of extracts studied ranged from 0.1 to 1000 μg/mL while for constituents ranged from 0.01 to 500 μM.

Results:

In rat liver microsomes, UGT activity was inhibited by the ethanol extract (IC₅₀ =279.74 ± 16.33 μg/mL). Both UGT1A1 and UGT2B7 were inhibited by the ethanol and aqueous extracts with IC₅₀ values ranging between 9.59–22.76 μg/mL and 110.71–526.65 μg/Ml, respectively. Rat liver GST and human GST Pi-1 were inhibited by ethanol and aqueous extracts, respectively (IC₅₀ =255.00 ± 13.06 μg/mL and 580.80 ± 18.56 μg/mL). Xanthorrhizol was the better inhibitor of UGT1A1 (IC₅₀ 11.30 ± 0.27 μM) as compared to UGT2B7 while curcumene did not show any inhibition. For GST, both constituents did not show any inhibition.

Conclusion:

These findings suggest that C. xanthorrhiza have the potential to cause herb-drug interaction with drugs that are primarily metabolized by UGT and GST enzymes.

SUMMARY

Findings from this study would suggest which of Curcuma xanthorrhiza extracts and constituents that would have potential interactions with drugs which are highly metabolized by UGT and GST enzymes. Further clinical studies can then be designed if needed to evaluate the in vivo pharmacokinetic relevance of these interactions

Abbreviations Used: BSA: Bovine serum albumin, CAM: Complementary and alternative medicine, cDNA: Complementary deoxyribonucleic acid, CDNB: 1-Chloro-2,4-dinitrobenzene, CuSO4.5H2O: Copper(II) sulfate pentahydrate, CXEE: Curcuma xanthorrhiza ethanol extract, CXAE: Curcuma xanthorrhiza aqueous extract, GC-MS: Gas chromatography-mass spectroscopy, GSH: Glutathione, GST: Glutathione S-transferase, KCl: Potassium chloride, min: Minutes, MgCl₂: Magnesium chloride, mg/mL: Concentration (weight of test substance in milligrams per volume of test concentration), mM: Milimolar, Na₂CO₃: Sodium carbonate, NaOH: Sodium hydroxide, nmol: nanomol, NSAIDs: Non-steroidal antiinflammatory drug, p-NP: para-nitrophenol, RLU: Relative light unit, SEM: Standard error of mean, UDPGA: UDP-glucuronic acid, UGT: UDP-glucuronosyltransferase.

Xanthorrhizol: a review of its pharmacological activities and anticancer properties

Xanthorrhizol (XNT) is a bisabolane-type sesquiterpenoid compound extracted from Curcuma xanthorrhiza Roxb. It has been well established to possess a variety of biological activities such as anticancer, antimicrobial, anti-inflammatory, antioxidant, antihyperglycemic, antihypertensive, antiplatelet, nephroprotective, hepatoprotective, estrogenic and anti-estrogenic effects. Since many synthetic drugs possess toxic side effects and are unable to support the increasing prevalence of disease, there is significant interest in developing natural product as new therapeutics. XNT is a very potent natural bioactive compound that could fulfil the current need for new drug discovery. Despite its importance, a comprehensive review of XNT's pharmacological activities has not been published in the scientific literature to date. Here, the present review aims to summarize the available information in this area, focus on its anticancer properties and indicate the current status of the research. This helps to facilitate the understanding of XNT's pharmacological role in drug discovery, thus suggesting areas where further research is required.

Cytotoxic Active Constituents of Essential Oils of Curcuma longa and Curcuma zanthorrhiza

The polar and apolar fractions of Curcuma longa and C. zanthorriza enriched by ar-turmerone, ar-curcumene and xanthorrizol were screened for cytotoxic activity against the HeLa cell line. Actinomycin D and curcumin were used as reference samples, both known for their cytotoxic properties. Amongst all fractions tested, the xanthorrizol fraction (CC50: 26.1±1.9 μM) showed the strongest cytotoxic properties similar to those of curcumin (CC50: 8.1±1.7 μM). Further studies also revealed that the cytotoxic effects of the extracts and pure compounds are caused by apoptosis induction identified by the cleaved form of PARP protein

Anticancer effects of brucine and gemcitabine combination in MCF-7 human breast cancer cells

This study was designed to investigate the combination effects of brucine and gemcitabine, each with anticancer properties, in MCF-7 human breast cancer cells in culture. With regard to cell viability, effects of both the drugs and their combinations were inversely proportional to dose and time. For various proportional drug combinations studied, combination effects were analysed using CompuSyn software. The analyses revealed synergistic and/or additive effects regarding cell viability, anchorage-independent growth and cell migration. Combination analyses exhibited diversified impacts of the type of combination treatment, namely pretreatment with either drug followed by exposure to the other, or treatment with both drugs at the same time. Compared with untreated cells, combination treatment of asynchronised MCF-7 cells resulted in 17.2 × decrease in G2 phase, increasing G1 (2.1 × ) and S (1.5 × ) phase cells in cell cycle analysis. Brucine, either individually or in combination, but not gemcitabine, inhibited NF-kB subunit (p65) expression in MCF-7 cells.

In vitro cytotoxicity of Artemisia vulgaris L. essential oil is mediated by a mitochondria-dependent apoptosis in HL-60 leukemic cell line

Background

The essential oil (EO) of Artemisia vulgaris L. has been traditionally used worldwide for treating a large number of diseases. Although major components in A. vulgaris EO have been shown to inhibit growth of different cancer cells, as pure compounds or part of other plants extracted oil, no information is known about its anti-proliferative activities. Therefore, the current investigation has evaluated the toxicity of the plant extracted oil from buds (AVO-b) and leaves (AVO-l) and characterized their growth inhibitory effects on cancer cells.

Methods

AVO-b and AVO-l from A. vulgaris L. were extracted by hydrodistillation, and their effect on the viability of human HL-60 promyelocytic leukemia and various other cancer cell lines was tested using MTT assay. Flow cytometric analysis of apoptosis, DNA fragmentation assay, caspases enzymatic activities and Western blotting were used to determine the apoptotic pathway triggered by their action on HL-60 cells.

Results

Low concentrations of AVO-b and AVO-l inhibited the growth of HL-60 cells in a dose- and time-dependent manner. Employing flow cytometric, DNA fragmentation and caspase activation analyses, demonstrated that the cytotoxic effect of the oils is mediated by a caspase-dependent apoptosis. Kinetic studies in the presence and absence specific caspase inhibitors showed that activation of caspase-8 was dependent and subsequent to the activation of caspases-9 and -3. In addition, the essential oil caused a disruption of the mitochondrial transmembrane potential (ΔΨ_m), increased the release of cytochrome c to the cytosol, and altered the expression of certain members of Bcl-2 family (Bcl-2, Bax and Bid), Apaf-1 and XIAP. Interestingly, low doses of AVO-b and AVO-1 also induced apoptosis in various cancer cell lines, but not in noncancerous cells.

Conclusions

The results demonstrate that the EO-induced apoptosis in HL-60 cells is mediated by caspase-dependent pathways, involving caspases-3, -9, and -8, which are initiated by Bcl-2/Bax/Bid-dependent loss of ΔΨ_m leading to release of cytochrome c to the cytoplasm to activate the caspase cascade. The finding that AVO-b and AVO-l are more efficient to induce apoptosis in different cancer cell lines than noncancerous cells, suggests that A. vulgaris might be a promising source for new anticancer agents.

Cytotoxic effect of Alpinia scabra (Blume) Náves extracts on human breast and ovarian cancer cells

Background

Alpinia scabra, locally known as 'Lengkuas raya’, is an aromatic, perennial and rhizomatous herb from the family Zingiberaceae. It is a wild species which grows largely on mountains at moderate elevations in Peninsular Malaysia, but it can also survive in the lowlands like in the states of Terengganu and Northern Johor. The present study reports the cytotoxic potential of A. scabra extracts from different parts of the plant.

Methods

The experimental approach in the present study was based on a bioassay-guided fractionation. The crude methanol and fractionated extracts (hexane, chloroform and water) from different parts of A. scabra (leaves, rhizomes, roots and pseudo stems) were prepared prior to the cytotoxicity evaluation against human ovarian (SKOV-3) and hormone-dependent breast (MCF7) carcinoma cells. The identified cytotoxic extracts were then subjected to chemical investigations in order to identify the active ingredients. A normal human lung fibroblast cell line (MRC-5) was used to determine the specificity for cancerous cells. The cytotoxic extracts and fractions were also subjected to morphological assessment, DNA fragmentation analysis and DAPI nuclear staining.

Results

The leaf (hexane and chloroform) and rhizome (chloroform) extracts showed high inhibitory effect against the tested cells. Ten fractions (LC1-LC10) were yielded after purification of the leaf chloroform extract. Fraction LC4 which showed excellent cytotoxic activity was further purified and resulted in 17 sub-fractions (VLC1-VLC17). Sub-fraction VLC9 showed excellent cytotoxicity against MCF7 and SKOV-3 cells but not toxic against normal MRC-5 cells. Meanwhile, eighteen fractions (RC1-RC18) were obtained after purification of the rhizome chloroform extract, of which fraction RC5 showed cytotoxicity against SKOV-3 cells with high selectivity index. There were marked morphological changes when observed using phase-contrast inverted microscope, DAPI nuclear staining and also DNA fragmentations in MCF7 and SKOV-3 cells after treatment with the cytotoxic extracts and fractions which were indicative of cell apoptosis. Methyl palmitate and methyl stearate were identified in the hexane leaf extract by GC-MS analysis.

Conclusions

The data obtained from the current study demonstrated that the cell death induced by cytotoxic extracts and fractions of A. scabra may be due to apoptosis induction which was characterized by apoptotic morphological changes and DNA fragmentation. The active ingredients in the leaf sub-fraction VLC9 and rhizome fraction RC5 may lead to valuable compounds that have the ability to kill cancer cells but not normal cells.

Characterization of synergistic anti-cancer effects of docosahexaenoic acid and curcumin on DMBA-induced mammary tumorigenesis in mice

BACKGROUND

The major obstacles to the successful use of individual nutritional compounds as preventive or therapeutic agents are their efficacy and bioavailability. One approach to overcoming this problem is to use combinations of nutrients to induce synergistic effects. The objective of this research was to investigate the synergistic effects of two dietary components: docosahexaenoic acid (DHA), an omega-3 fatty acid present in cold-water fish, and curcumin (CCM), an herbal nutrient present in turmeric, in an in vivo model of DMBA-induced mammary tumorigenesis in mice.

METHODS

We used the carcinogen DMBA to induce breast tumors in SENCAR mice on control, CCM, DHA, or DHA + CCM diets. Appearance and tumor progression were monitored daily. The tumors were harvested 15 days following their first appearance for morphological and immunohistological analysis. Western analysis was performed to determine expression of maspin and survivin in the tumor tissues. Characterization of tumor growth was analyzed using appropriate statistical methods. Otherwise all other results are reported as mean ± SD and analyzed with one-way ANOVA and Tukey's post hoc procedure.

RESULTS

Analysis of gene microarray data indicates that combined treatment with DHA + CCM altered the profile of "PAM50" genes in the SK-BR-3 cell line from an ER⁻/Her-2⁺ to that resembling a "normal-like" phenotype. The in vivo studies demonstrated that DHA + CCM treatment reduced the incidence of breast tumors, delayed tumor initiation, and reduced progression of tumor growth. Dietary treatment had no effect on breast size development, but tumors from mice on a control diet (untreated) were less differentiated than tumors from mice fed CCM or DHA + CCM diets. The synergistic effects also led to increased expression of the pro-apoptotic protein, maspin, but reduced expression of the anti-apoptotic protein, survivin.

CONCLUSIONS

The SK-BR-3 cells and DMBA-induced tumors, both with an ER⁻ and Her-2⁺ phenotype, were affected by the synergistic interaction of DHA and CCM. This suggests that the specific breast cancer phenotype is an important factor for predicting efficacy of these nutraceuticals. The combination of DHA and CCM is potentially a dietary supplemental treatment for some breast cancers, likely dependent upon the molecular phenotype of the cancer.

Synergetic effect of SLN-curcumin and LDH-5-Fu on SMMC-7721 liver cancer cell line

Curcumin and 5-Fluorouracil (5-Fu) have been reported to have anticancer potentials and show certain synergetic effect on some cancer cell lines. However, the poor bioavailability and rapid metabolism limited their medical application. In this study, we encapsulated curcumin with solid lipid nanoparticles (SLN), 5-Fu with Layered double hydroxides (LDHs) separately and tested its properties and anticancer potentials. SLN-curcumin and LDH-5-Fu were determined to be 100 and 60 nm by Transmission Electron Microscopy detection, and the loading efficiency were 28%±2.5% and 16.7%±1.8%, individually. Furthermore, SLN-curcumin and LDH-5-Fu showed a significantly synergetic effect on SMMC-7721 cell stronger than plain drugs together, of which the Idrug loaded nano-carriers was only 0.315. FACS analysis revealed that the combination of SLN-curcumin and LDH-5-Fu induced 80.1% apoptosis in SMMC-7721 cells, which were 1.7-folds of the sum of the two plain drug loaded carriers. The results demonstrated the significant synergetic anticancer potentials of nano-encapsulated curcumin and 5-Fu, which could be further explored for the treatment of other carcinoma.

Discovery and antitumor activities of constituents from Cyrtomium fortumei (J.) Smith rhizomes

Background

Cyrtomium fortumei (J.) Smith is an important Chinese herbal medicine because of its biological functions. However, systematic and comprehensive studies on the phytochemicals from Cyrtomium fortumei (J.) Smith and their bioactivity are limited.

Results

Using the bioassay-guided technique, the ethyl acetate and n-BuOH extracts of the rhizomes of Cyrtomium fortumei (J.) Smith were shown to exhibit good antitumor activities, consequently leading to the isolation of 23 compounds. All compounds were isolated from the plant for the first time. The inhibitory activities of these compounds were investigated on tumor cells MGC-803, PC3, and A375 in vitro by MTT (thiazolyl blue tetrazolium bromide) assay, and the results showed that pimpinellin (3) had potent cytotoxic activities against the three cell lines, with the IC₅₀ values of 14.4 ± 0.3 μM, 20.4 ± 0.5 μM, and 29.2 ± 0.6 μM, respectively. The mechanism of the antitumor action indicated that pimpinellin inhibited the growth of MGC-803 cells via the induction of tumor cell apoptosis, with apoptosis ratio of 27.44% after 72 h of treatment at 20 μM.

Conclusions

This study suggests that most of the compounds from the roots of Cyrtomium fortumei (J.) Smith could inhibit the growth of human carcinoma cells. Moreover, pimpinellin inhibited the growth of tumor cells via the induction of tumor cell apoptosis.

A review of the literature and latest advances in research of Piper sarmentosum

CONTEXT

Piper sarmentosum Roxb. (Piperaceae) is a traditional medicinal as well as a culinary plant in South East Asian countries, whereby aerial parts of the plant are consumed as a vegetable in various forms and the whole plant or parts are used as folk remedies, alone or in combination with other herbs, to treat various ailments. The plant has extensively been investigated in a broad range of studies to provide scientific evidence for folklore claims or to find new therapeutic uses; however, heretofore, a summary of the data are not available.

OBJECTIVE

In order to describe nutritional and therapeutic potential of P. sarmentosum and summarize scientific evidence that supports traditional claims, a literature review and latest advances in research of the plant are given herein.

MATERIALS AND METHODS

The literature has been retrieved from a number of databases such as Google Scholar, PubMed, Medline, Science Direct and SciFinder. The articles related to synthetic work, ecology and agriculture have been excluded.

RESULTS AND DISCUSSION

The review has not only revealed a number of pharmacological activities supporting the traditional claims but indicates new prospects for the plant. Antiangiogenic activity and toxicity studies suggest the usage of the plant in treating diseases involving neo-vascularization. The available efficacy, safety, pharmacokinetic and stability data urge clinical studies on extracts of the plant.

CONCLUSION

The present review may be helpful to future researchers intending to investigate the plant and natural pharmaceutical industry for preparing evidence-based formulations.

Xanthorrhizol induced DNA fragmentation in HepG2 cells involving Bcl-2 family proteins

Xanthorrhizol is a plant-derived pharmacologically active sesquiterpenoid compound isolated from Curcuma xanthorrhiza. Previously, we have reported that xanthorrhizol inhibited the proliferation of HepG2 human hepatoma cells by inducing apoptotic cell death via caspase activation. Here, we attempt to further elucidate the mode of action of xanthorrhizol. Apoptosis in xanthorrhizol-treated HepG2 cells as observed by scanning electron microscopy was accompanied by truncation of BID; reduction of both anti-apoptotic Bcl-2 and Bcl-X(L) expression; cleavage of PARP and DFF45/ICAD proteins and DNA fragmentation. Taken together, these results suggest xanthorrhizol as a potent antiproliferative agent on HepG2 cells by inducing apoptosis via Bcl-2 family members. Hence we proposed that xanthorrhizol could be used as an anti-liver cancer drug for future studies.

The role of nutraceuticals in chemoprevention and chemotherapy and their clinical outcomes

The genesis of cancer is often a slow process and the risk of developing cancer increases with age. Altering a diet that includes consumption of beneficial phytochemicals can influence the balance and availability of dietary chemopreventive agents. In chemopreventive approaches, foods containing chemicals that have anticancer properties can be supplemented in diets to prevent precancerous lesions from occurring. This necessitates further understanding of how phytochemicals can potently maintain healthy cells. Fortunately there is a plethora of plant-based phytochemicals although few of them are well studied in terms of their application as cancer chemopreventive and therapeutic agents. In this analysis we will examine phytochemicals that have strong chemopreventive and therapeutic properties in vitro as well as the design and modification of these bioactive compounds for preclinical and clinical applications. The increasing potential of combinational approaches using more than one bioactive dietary compound in chemoprevention or cancer therapy will also be evaluated. Many novel approaches to cancer prevention are on the horizon, several of which are showing great promise in saving lives in a cost-effective manner.

Integrated standardization concept for Angelica botanicals using quantitative NMR

Despite numerous in vitro/vivo and phytochemical studies, the active constituents of Angelica sinensis (AS) have not been conclusively identified for the standardization to bioactive markers. Phytochemical analyses of AS extracts and fractions that demonstrate activity in a panel of in vitro bioassays, have repeatedly pointed to ligustilide as being (associated with) the active principle(s). Due to the chemical instability of ligustilide and related issues in GC/LC analyses, new methods capable of quantifying ligustilide in mixtures that do not rely on an identical reference standard are in high demand. This study demonstrates how NMR can satisfy the requirement for simultaneous, multi-target quantification and qualitative identification. First, the AS activity was concentrated into a single fraction by RP-solid-phase extraction, as confirmed by an alkaline phosphatase, (anti-)estrogenicity and cytotoxicity assay. Next, a quantitative (1)H NMR (qHNMR) method was established and validated using standard compounds and comparing processing methods. Subsequent 1D/2D NMR and qHNMR analysis led to the identification and quantification of ligustilide and other minor components in the active fraction, and to the development of quality criteria for authentic AS preparations. The absolute and relative quantities of ligustilide, six minor alkyl phthalides, and groups of phenylpropanoids, polyynes, and poly-unsaturated fatty acids were measured by a combination of qHNMR and 2D COSY. The qNMR approach enables multi-target quality control of the bioactive fraction, and enables the integrated biological and chemical standardization of AS botanicals. This methodology can potentially be transferred to other botanicals with active principles that act synergistically, or that contain closely related and/or constituents, which have not been conclusively identified as the active principles.

A synergistic antiproliferation effect of curcumin and docosahexaenoic acid in SK-BR-3 breast cancer cells: unique signaling not explained by the effects of either compound alone

Background

Breast cancer is a collection of diseases in which molecular phenotypes can act as both indicators and mediators of therapeutic strategy. Therefore, candidate therapeutics must be assessed in the context of multiple cell lines with known molecular phenotypes. Docosahexaenoic acid (DHA) and curcumin (CCM) are dietary compounds known to antagonize breast cancer cell proliferation. We report that these compounds in combination exert a variable antiproliferative effect across multiple breast cell lines, which is synergistic in SK-BR-3 cells and triggers cell signaling events not predicted by the activity of either compound alone.

Methods

Dose response curves for CCM and DHA were generated for five breast cell lines. Effects of the DHA+ CCM combination on cell proliferation were evaluated using varying concentrations, at a fixed ratio, of CCM and DHA based on their individual ED₅₀. Detection of synergy was performed using nonlinear regression of a sigmoid dose response model and Combination Index approaches. Cell molecular network responses were investigated through whole genome microarray analysis of transcript level changes. Gene expression results were validated by RT-PCR, and western blot analysis was performed for potential signaling mediators. Cellular curcumin uptake, with and without DHA, was analyzed via flow cytometry and HPLC.

Results

CCM+DHA had an antiproliferative effect in SK-BR-3, MDA-MB-231, MDA-MB-361, MCF7 and MCF10AT cells. The effect was synergistic for SK-BR-3 (ER^- PR^- Her2⁺) relative to the two compounds individually. A whole genome microarray approach was used to investigate changes in gene expression for the synergistic effects of CCM+DHA in SK-BR-3 cells lines. CCM+DHA triggered transcript-level responses, in disease-relevant functional categories, that were largely non-overlapping with changes caused by CCM or DHA individually. Genes involved in cell cycle arrest, apoptosis, inhibition of metastasis, and cell adhesion were upregulated, whereas genes involved in cancer development and progression, metastasis, and cell cycle progression were downregulated. Cellular pools of PPARγ and phospho-p53 were increased by CCM+DHA relative to either compound alone. DHA enhanced cellular uptake of CCM in SK-BR-3 cells without significantly enhancing CCM uptake in other cell lines.

Conclusions

The combination of DHA and CCM is potentially a dietary supplemental treatment for some breast cancers, likely dependent upon molecular phenotype. DHA enhancement of cellular curcumin uptake is one potential mechanism for observed synergy in SK-BR-3 cells; however, transcriptomic data show that the antiproliferation synergy accompanies many signaling events unique to the combined presence of the two compounds.

Concurrent Sulforaphane and Eugenol Induces Differential Effects on Human Cervical Cancer Cells

Background. The concept of combination of chemoprevention holds great potential for cancer management as lower, clinically tolerable doses of individual agents could be achieved through therapeutic synergy. However, elucidation of their possible interactions—additive, synergistic, or antagonistic—must be thoroughly studied before considering for clinical use. Methods. To evaluate the effect of combination treatment of sulforaphane (SFN) and eugenol on HeLa cells, the authors performed cell viability assay, apoptosis assay, and reverse transcription polymerase chain reaction for gene expression analysis. Calculations of combination effects were expressed as a combination index (CI) with CI < 1, CI = 1, or CI > 1 representing synergism, additivity, or antagonism, respectively. Results. Simultaneous treatment with variable dose combinations of SFN and eugenol resulted in differential effects with an antagonistic effect at lower and synergistic at higher sub-lethal doses as reflected in cell cytotoxicity and apoptosis induction. Importantly, gemcitabine used in conjunction with the low- and high-dose combinations showed no significant cell death at lower doses suggesting that cell cytotoxicity is proportional to gemcitabine alone, whereas at higher sublethal doses of SFN and eugenol, it was found to act in a synergistic manner with gemcitabine. Furthermore, SFN and eugenol combinations at synergistic dose significantly downregulated the expression of Bcl-2, COX-2 and IL-β but not the antagonistic combinations. Conclusion. This study clearly indicates that 2 (or more) chemopreventive agents can act antagonistically or synergistically necessitating elucidation of possible mechanistic interactions for favorable and reliable outcomes of dietary components in the field of cancer prevention.

Chalcones and dihydrochalcones augment TRAIL-mediated apoptosis in prostate cancer cells

Chalcones and dihydrochalcones exhibit chemopreventive and antitumor activity. TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) is a natural endogenous anticancer agent. We examined the cytotoxic and apoptotic effect of chalcones and dihydrochalcones on TRAIL-mediated apoptosis in LNCaP prostate cancer cells. The cytotoxicity was evaluated by the MTT and LDH assays. The apoptosis was detected using annexin V-FITC by flow cytometry and fluorescence microscopy. The DeltaPsim was evaluated using DePsipher staining by fluorescence microscopy. Our study showed that two tested chalcones (chalcone and 2',6'dihydroxy-4'-methoxychalcone) and three dihydrochalcones (2',6'-dihydroxy-4'4-dimethoxydihydrochalcone, 2',6'-dihydroxy-4'-methoxydihydro- chalcone, and 2',4',6'-trihydroxydihydrochalcone, called phloretin) markedly augmented TRAIL-induced apoptosis and cytotoxicity in LNCaP cells and confirmed the significant role of chalcones in chemoprevention of prostate cancer.

Curcumin induces chemo/radio-sensitization in ovarian cancer cells and curcumin nanoparticles inhibit ovarian cancer cell growth

Background

Chemo/radio-resistance is a major obstacle in treating advanced ovarian cancer. The efficacy of current treatments may be improved by increasing the sensitivity of cancer cells to chemo/radiation therapies. Curcumin is a naturally occurring compound with anti-cancer activity in multiple cancers; however, its chemo/radio-sensitizing potential is not well studied in ovarian cancer. Herein, we demonstrate the effectiveness of a curcumin pre-treatment strategy for chemo/radio-sensitizing cisplatin resistant ovarian cancer cells. To improve the efficacy and specificity of curcumin induced chemo/radio sensitization, we developed a curcumin nanoparticle formulation conjugated with a monoclonal antibody specific for cancer cells.

Methods

Cisplatin resistant A2780CP ovarian cancer cells were pre-treated with curcumin followed by exposure to cisplatin or radiation and the effect on cell growth was determined by MTS and colony formation assays. The effect of curcumin pre-treatment on the expression of apoptosis related proteins and β-catenin was determined by Western blotting or Flow Cytometry. A luciferase reporter assay was used to determine the effect of curcumin on β-catenin transcription activity. The poly(lactic acid-co-glycolic acid) (PLGA) nanoparticle formulation of curcumin (Nano-CUR) was developed by a modified nano-precipitation method and physico-chemical characterization was performed by transmission electron microscopy and dynamic light scattering methods.

Results

Curcumin pre-treatment considerably reduced the dose of cisplatin and radiation required to inhibit the growth of cisplatin resistant ovarian cancer cells. During the 6 hr pre-treatment, curcumin down regulated the expression of Bcl-X_L and Mcl-1 pro-survival proteins. Curcumin pre-treatment followed by exposure to low doses of cisplatin increased apoptosis as indicated by annexin V staining and cleavage of caspase 9 and PARP. Additionally, curcumin pre-treatment lowered β-catenin expression and transcriptional activity. Nano-CUR was successfully generated and physico-chemical characterization of Nano-CUR indicated an average particle size of ~70 nm, steady and prolonged release of curcumin, antibody conjugation capability and effective inhibition of ovarian cancer cell growth.

Conclusion

Curcumin pre-treatment enhances chemo/radio-sensitization in A2780CP ovarian cancer cells through multiple molecular mechanisms. Therefore, curcumin pre-treatment may effectively improve ovarian cancer therapeutics. A targeted PLGA nanoparticle formulation of curcumin is feasible and may improve the in vivo therapeutic efficacy of curcumin.

Evaluation of the antinociceptive activity and acute oral toxicity of standardized ethanolic extract of the rhizome of Curcuma xanthorrhiza Roxb

Ethanolic extract of Curcuma xanthorrhiza was used to evaluate the analgesic and toxicity effects in vivo. The extract was standardized using GC-MS, which showed that 1 mg of Curcuma xanthorrhiza ethanolic extract contains 0.1238 mg of xanthorrhizol. The analgesic activity was studied in rats using three different models, namely the hot plate test, tail flick test and formalin-induced pain test. The acute oral toxicity was examined by the oral administration of standardized Curcuma xanthorrhiza ethanolic extract in mice at doses ranging from 300–5,000 mg/kg and observation for 14 days. Standardized Curcuma xanthorrhiza ethanolic extract did not show significant analgesic effect in the hot plate and tail flick tests. However, in the formalin-induced pain test, Curcuma xanthorrhiza ethanolic extract significantly (P < 0.05) suppressed the paw licking time of rats in both early and late phases at doses 200 and 400 mg/kg of the extract, respectively. In the acute oral toxicity study, Curcuma xanthorrhiza ethanolic extract did not show any toxic effects in mice at 5 g/kg. These experimental results suggest that the standardized Curcuma xanthorrhiza ethanolic extract showed peripheral and central antinociceptive activity associated with neurogenic pain as well as a relative absence of toxic effects which could compromise the medicinal use of this plant in folk medicine.

Curcumin and cancer cells: how many ways can curry kill tumor cells selectively?

Cancer is a hyperproliferative disorder that is usually treated by chemotherapeutic agents that are toxic not only to tumor cells but also to normal cells, so these agents produce major side effects. In addition, these agents are highly expensive and thus not affordable for most. Moreover, such agents cannot be used for cancer prevention. Traditional medicines are generally free of the deleterious side effects and usually inexpensive. Curcumin, a component of turmeric (Curcuma longa), is one such agent that is safe, affordable, and efficacious. How curcumin kills tumor cells is the focus of this review. We show that curcumin modulates growth of tumor cells through regulation of multiple cell signaling pathways including cell proliferation pathway (cyclin D1, c-myc), cell survival pathway (Bcl-2, Bcl-xL, cFLIP, XIAP, c-IAP1), caspase activation pathway (caspase-8, 3, 9), tumor suppressor pathway (p53, p21) death receptor pathway (DR4, DR5), mitochondrial pathways, and protein kinase pathway (JNK, Akt, and AMPK). How curcumin selectively kills tumor cells, and not normal cells, is also described in detail.