8,8-bis-(Dihydroconiferyl)-diferulate displayed impressive cytotoxicity towards a panel of human and animal cancer cells

BackgroundRecalcitrant cancers appear as a major obstacle to chemotherapy, prompting scientists to intensify the search for novel drugs to tackle the cell lines expressing multi-drug resistant (MDR) phenotypes.PurposeThe purpose of this study was to evaluate the antiproliferative potential of a ferrulic acid derivative, 8,8-bis-(dihydroconiferyl)-diferulate (DHCF2) on a panel of 18 cancer cell lines, including various sensitive and drug-resistant phenotypes, belonging to human and animals. The mode of induction of cell death by this compound was further studied.MethodsThe antiproliferative activity, autophagy, ferroptotic and necroptotic cell death were evaluated by the resazurin reduction assay (RRA). CCRF-CEM leukemia cells were used for all mechanistic studies. A caspase-Glo assay was applied to evaluate the activity of caspases. Cell cycle analysis (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP) (JC-1) and reactive oxygen species (ROS) (H₂DCFH-DA) were assessed by flow cytometry.ResultsDHCF2 demonstrated impressive cytotoxic effects towards the 18 cancer cell lines tested, with IC₅₀ values all below 6.5 µM. The obtained IC₅₀ values were in the range of 1.17 µM (towards CCRF-CEM leukemia cells) to 6.34 µM (towards drug-resistant HCT116 p53^−/− human colon adenocarcinoma cells) for DHCF2 and from 0.02 µM (against CCRF-CEM cells) to 122.96 µM (against multidrug-resistant CEM/ADR5000 leukemia cells) for the reference drug, doxorubicin. DHCF2 had IC₅₀ values lower than those of doxorubicin, against CEM/ADR5000 cells and on some melanoma cell lines, such as MaMel-80a cells, Mel-2a cells, MV3 cells and SKMel-505 cells. DHCF2 induced autophagy as well as apoptosis in CCRF-CEM cells though caspases activation, MMP alteration and increase of ROS production.ConclusionThe studied diferulic acid, DHCF2, is a promising antiproliferative compound. It deserves further indepth investigations with the ultimate aim to develop a novel drug to fight cancer drug resistance.     

Cytotoxicity of compounds from Xylopia aethiopica towards multi-factorial drug-resistant cancer cells

IntroductionMultidrug resistance (MDR) in cancer represent a major hurdle in chemotherapy. Previously, the methanol extract of the medicinal spice Xylopia aethiopica displayed considerable cytotoxicity against multidrug resistant (MDR) cancer cell lines.MethodsThe present study was designed to assess the cytotoxicity of compounds, 16α-hydroxy-ent-kauran-19-oic acid (2), 3,4′,5-trihydroxy-6″,6″-dimethylpyrano[2,3-g]flavone (3), isotetrandrine (5) and trans-tiliroside (6) derived from the methanol crude extract of Xylopia aethiopica against 9 drug-sensitive and -resistant cancer cell lines. The resazurin reduction assay was used to evaluate the cytotoxicity of these compounds, whilst caspase-Glo assay was used to detect caspase activation. Cell cycle, mitochondrial membrane potential (MMP) and levels of reactive oxygen species (ROS) were all analyzed via flow cytometry.ResultsFlavonoid 3 and alkaloid 5 also displayed IC₅₀ values ranging from 2.61 µM (towards leukemia CCRF-CEM cells) to 18.60 µM (towards gliobastoma multiforme U87MG.ΔEGFR cells) and from 1.45 µM (towards HepG2 cells) to 7.28 µM (towards MDA-MB-231-pcDNA cells), respectively. IC₅₀ values ranged from 0.20 µM (against CCRF-CEM cells) to 195.12 µM (against CEM/ADR5000 cells) for doxorubicin. Compound 3 induced apoptosis in leukemia CCRF-CEM cells mediated by the disruption of the MMP, whilst 5 induced apoptosis mediated by ROS production.ConclusionsCompounds 2 and 5 represent potential cytotoxic phytochemicals that deserve more investigations to develop novel antineoplastic drugs against multifactorial drug-resistant cancers.     

Cytotoxicity and modes of action of three naturally occurring xanthones (8-hydroxycudraxanthone G,morusignin I and cudraxanthone I) against sensitive and multidrug-resistant cancer cell lines

BackgroundResistance of cancer to chemotherapy remains a challenging issue for scientists as well as physicians. Naturally occurring xanthones possess a variety of biological activities such as anti-inflammatory, anti-bacterial, and anti-cancer effects. The present study was aimed at investigating the cytotoxicity and the modes of action of three naturally occurring xanthones namely, morusignin I (1), 8-hydroxycudraxanthone G (2) and cudraxanthone I (3) against a panel of nine cancer cell lines, including various sensitive and drug-resistant phenotypes.MethodsThe cytotoxicity of the compounds was determined using a resazurin reduction assay, whereas the caspase-Glo assay was used to detect the activation of caspases 3/7, caspase 8 and caspase 9 in cells treated with compounds 3. Flow cytometry was used for cell cycle analysis and detection of apoptotic cells, analysis of mitochondrial membrane potential (MMP) as well as measurement of reactive oxygen species (ROS).ResultsCompounds 1 and 3 inhibited the proliferation of all tested cancer cell lines including sensitive and drug-resistant phenotypes. Compound 2 was active on 8/9 cell lines with the IC₅₀ values ranging from 16.65 μM (against leukemia CCRF-CEM cells) to 70.38 μM (against hepatocarcinoma HepG2 cells). The IC₅₀ value ranged from 7.15 μM (against CCRF-CEM cells) to 53.85 μM [against human glioblastoma U87MG.ΔEGFR cells] for compound 1, and from 2.78 μM (against breast cancer MDA-MB231 BCRP cells) to 22.49 μM (against U87MG cells) for compound 3. P-glycoprotein expressing CEM/ADR5000 cells were cross-resistant to compounds 1 and 2 (4.21- to 610-fold) while no cross-resistance or even collateral cross-sensitivity were observed in other drug-resistant cell lines to the three compounds. Normal AML12 liver cells were more resistant to the three compounds than HepG2 liver cancer cells. Compounds 3 arrested the cell cycle between G0/G1 and S phases, strongly induced apoptosis via caspases 3/7, caspase 8, caspase 9 activation and disrupted the MMP in CCRF-CEM cells.ConclusionsThe cytotoxicity of the studied xanthones and especially compound 3 deserve more detailed exploration in the future to develop novel anticancer drugs against sensitive and otherwise drug-resistant phenotypes.     

Cytotoxicity of three naturally occurring flavonoid derived compounds (artocarpesin,cycloartocarpesin and isobavachalcone) towards multi-factorial drug-resistant cancer cells

IntroductionCancer remains an aggressive deadly disease, if drug resistance develops. This problem is aggravated by the fact that multiple rather than single mechanisms are involved in resistance and that multidrug resistance (MDR) phenomena cause inefficacy of many clinical established anticancer drugs. We are seeking for novel cytotoxic phytochemicals to combat drug-resistant tumour cells.MethodsIn the present study, we investigated the cytotoxicity of three naturally occurring flavonoids including two flavones artocarpesin (1) and cycloartocarpesin (2) and one chalcone, isobavachalcone (3) against 9 drug-sensitive and MDR cancer cell lines. The resazurin reduction assay was used to evaluate the cytotoxicity of these compounds, whilst caspase-Glo assay was used to detect caspase activation. Cell cycle, mitochondrial membrane potential (MMP) and levels of reactive oxygen species (ROS) were all analysed via flow cytometry.ResultsFlavones 1 and 2 as well as chalcone 3 displayed cytotoxic effects at various extent on all the 9 tested cancer cell lines with IC₅₀ values respectively below 106 µM, 50 µM and 25 µM. The IC₅₀ values for the three investigational flavonoids ranged from 23.95 µM (towards hepatocarcinoma HepG2 cells) to 105 µM [towards colon carcinoma HCT116 (p53^−/−) cells] for 1, from 15.51 µM (towards leukemia CCRF-CEM cells) to 49.83 µM [towards glioblastoma U87MG.ΔEGFR cells] for 2 and from 2.30 µM (towards CCRF-CEM cells) to 23.80 µM [towards colon carcinoma HCT116 (p53^+/+) cells] for 3 and from 0.20 µM (towards CCRF-CEM cells) to 195.12 µM (towards leukemia CEM/ADR5000 cells) for doxorubicin. Compounds 2 and 3 induced apoptosis in CCRF-CEM leukemia cells, mediated by caspase activation and the disruption of MMP.ConclusionsThe three tested flavonoids and mostly chalcone 3 are potential cytotoxic natural products that deserve more investigations to develop novel antineoplastic drugs against multifactorial drug-resistant cancers.     

Cytotoxicity of a naturally occurring furoquinoline alkaloid and four acridone alkaloids towards multi-factorial drug-resistant cancer cells

IntroductionChemotherapy is one of the preferred mode of treatment of malignancies, but is complicated by the expression of diverse resistance mechanisms of cancer cells.MethodsIn the present study, we investigated the cytotoxicity of five alkaloids including a furoquinoline montrofoline (1) and four acridones namely 1-hydroxy-4-methoxy-10-methylacridone (2), norevoxanthine (3), evoxanthine (4), 1,3-dimethoxy-10-methylacridone (5) against 9 drug-sensitive and multidrug-resistant (MDR) cancer cell lines. The resazurin reduction assay was used to evaluate the cytotoxicity of these compounds, whilst caspase-Glo assay was used to detect caspase activation. Cell cycle, mitochondrial membrane potential (MMP) and levels of reactive oxygen species (ROS) were all analyzed via flow cytometry.ResultsFuroquinoline 1 as well as the acridone alkaloids 2–5 displayed cytotoxic effects with IC₅₀ values below 138 µM on all the 9 tested cancer cell lines. The IC₅₀ values ranged from 41.56 µM (towards hepatocarinoma HepG2 cells) to 90.66 µM [towards colon carcinoma HCT116 (p53^−/−) cells] for 1, from 6.78 µM [towards HCT116 (p53^−/−) cells) to 106.47 µM [towards breast adenocarcinoma MDA-MB-231-pcDNA cells] for 2, from 5.72 µM (towards gliobastoma U87MG.ΔEGFR cells) to 137.62 µM (towards leukemia CCRF-CEM cells] for 3, from 6.11 µM [towards HCT116 (p53^+/+) cells] to 80.99 µM (towards HepG2 cells] for 4, from 3.38 µM (towards MDA-MB-231-BCRP cells) to 58.10 µM (towards leukemia CEM/ADR5000 cells] for 5 and from 0.20 µM (against CCRF-CEM cells) to 195.12 µM (against CEM/ADR5000 cells) for doxorubicin. Acridone alkaloid 5 induced apoptosis in CCRF-CEM leukemia cells, mediated by increased ROS production.ConclusionsThe five tested alkaloids and mostly acridone 5 are potential cytotoxic natural products that deserve more investigations to develop novel cytotoxic compounds against multifactorial drug-resistant cancers.     

Cytotoxicity and modes of action of 4′-hydroxy-2′,6′-dimethoxychalcone and other flavonoids toward drug-sensitive and multidrug-resistant cancer cell lines

IntroductionResistance of cancer to chemotherapy is a main cause in treatment failure. Naturally occurring chalcones possess a wide range of biological activities including anti-cancer effects. In this work, we evaluated the antiproliferative activity of three chalcones [4′-hydroxy-2′,6′-dimethoxychalcone (1), cardamomin (2), 2′,4′-dihydroxy-3′,6′-dimethoxychalcone (3)], and four flavanones [(S)-(–)-pinostrobin (4), (S)-(–)-onysilin (5) and alpinetin (6)] toward nine cancer cell lines amongst which were multidrug resistant (MDR) types.MethodsThe resazurin reduction assay was used to detect the antiproliferative activity of the studied samples whilst flow cytometry for the mechanistic studies of the most active molecule (1).ResultsIC₅₀ values in a range of 2.54 μM against CEM/ADR5000 leukemia cells to 58.63 μM toward hepatocarcinoma HepG2 cells were obtained with 1. The lowest IC₅₀ values of 8.59 μM for 2 and 10.67 μM for 3 were found against CCRF-CEM cells leukemia cells, whilst the corresponding values were above 80 μM for 4 and 6. P-glycoprotein-expressing and multidrug-resistant CEM/ADR5000 cells were much more sensitive toward compound 1 than toward doxorubicin and low cross-resistance or even collateral sensitivity was observed in other drug-resistent cell lines to this compound. Normal liver AML12 cells were more resistant to the studied compounds than HepG2 liver cancer cells, indicating tumor specificity at least to some extent. Compound 1 arrested the cell cycle between Go/G1 phase, strongly induced apoptosis via disrupted mitochondrial membrane potential (MMP) and increased production of reactive oxygen species (ROS) in the studied leukemia cell line.ConclusionsChalcone 1 was the best tested cytotoxic molecule and further studies will be performed in order to envisage its possible use in the fight against multifactorial resistant cancer cells.     

Synthesis and anticancer activity of bis-benzo[d][1,3]dioxol-5-yl thiourea derivatives with molecular docking study

New thiourea derivatives incorporating two benzo[d][1,3]dioxol-5-yl moieties have been synthesized through the reaction of two molecules of benzo[d][1,3]dioxol-5-yl isothiocyanate with one molecule of various diamino derivatives. The synthesized compounds were examined for their cytotoxic effects using SRB assay on three cancer cell lines HepG2, HCT116 and MCF-7. Most of compounds showed significant antitumor activity and some compounds showed strong results greater than the reference drug. As example, IC₅₀ values of 1,1′-(1,4-phenylene)bis(3-(benzo[d][1,3]dioxol-5-yl)thiourea) 5 were 2.38 µM for HepG2, 1.54 µM for HCT116 and 4.52 µM for MCF7, while the IC₅₀ values of standard drug doxorubicin were 7.46, 8.29 and 4.56 µM, respectively. Interestingly, these compounds were non cytotoxic toward the tested normal cell line (IC₅₀ value > 150 µM). The anticancer mechanisms were studied via EGFR inhibition assessment, annexin V-FITC apoptosis assessment, cell cycle analysis and study the effect on mitochondrial apoptosis pathway proteins Bax and Bcl-2 as well as molecular docking studies.     

Sublethal hyperthermia enhances anticancer activity of doxorubicin in chronically hypoxic HepG2 cells through ROS-dependent mechanism

Thermal ablation in combination with transarterial chemoembolization (TACE) has been reported to exert a more powerful antitumor effect than thermal ablation alone in hepatocellular carcinoma patients. However, the underlying mechanisms remain unclear. The purpose of the present study was to evaluate whether sublethal hyperthermia encountered in the periablation zone during thermal ablation enhances the anticancer activity of doxorubicin in chronically hypoxic (encountered in the tumor area after TACE) liver cancer cells and to explore the underlying mechanisms. In the present study, HepG2 cells precultured under chronic hypoxic conditions (1% oxygen) were treated in a 42°C water bath for 15 or 30 min, followed by incubation with doxorubicin. Assays were then performed to determine intracellular uptake of doxorubicin, cell viability, apoptosis, cell cycle, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and total antioxidant capacity. The results confirmed that sublethal hyperthermia enhanced the intracellular uptake of doxorubicin into hypoxic HepG2 cells. Hyperthermia combined with doxorubicin led to a greater inhibition of cell viability and increased apoptosis in hypoxic HepG2 cells as compared with hyperthermia or doxorubicin alone. In addition, the combination induced apoptosis by increasing ROS and causing disruption of MMP. Pretreatment with the ROS scavenger N-acetyl cysteine significantly inhibited the apoptotic response, suggesting that cell death is ROS-dependent. These findings suggested that sublethal hyperthermia enhances the anticancer activity of doxorubicin in hypoxic HepG2 cells via a ROS-dependent mechanism.     

Resveratrol enhances the cytotoxic profile of docetaxel and doxorubicin in solid tumour cell lines in vitro

Objectives: Resveratrol, with its robust antioxidant activity, has frequently been suggested as potentially having activity in cancer prevention and some recent reports have indicated that it has cancer treatment potential for several types of neoplasia. It has been found to block p‐glycoprotein and to protect against several chemotherapeutic agents’ side effects. In this study, we assessed interactive characteristics of resveratrol with docetaxel and doxorubicin and further investigated molecular bases of this interaction in cells of three different solid tumour lines (MCF‐7, HeLa and HepG2). Materials and methods and results: Resveratrol per se was found to have anti‐cancer properties, but with relatively low potency in all tested cell lines (IC₅₀ ranged from 35.1 to 83.8 μM). Doxorubicin and docetaxel showed IC₅₀ ranging from 0.48 to 0.72 μM and from 25.9 to 77.8 nM, respectively. Resveratrol in combination with doxorubicin and docetaxel significantly increased potencies of both chemotherapeutic agents showing IC₅₀ ranging from 0.12 to 0.34 μM and from 7.2 to 53.02 nM, respectively. The combination index showed synergistic interaction between resveratrol and doxorubicin or docetaxel on MCF‐7 cells, and additive interactions on HeLa and HepG2 cells. Real time PCR revealed that expression of Bax and Bcl‐2 was simultaneously elevated on combination of resveratrol with doxorubicin or docetaxel in all tested cell lines, whereas p53 exhibited marginal elevation in MCF‐7 and HepG2 cells. In addition, p‐glycoprotein efflux activity was significantly inhibited, with subsequent accumulation of p‐glycoprotein substrate in intracellular compartments. Expression level of mdr1 gene was downregulated after resveratrol combined with doxorubicin or docetaxel in all tested cell lines. Conclusion: Resveratrol potentiates cytotoxic properties of both cancer drugs used in the study through increasing their intracellular level due to p‐glycoprotein inhibition and downregulation of mdr1 gene.     

Novel benzotriazole N-acylarylhydrazone hybrids: Design,synthesis, anticancer activity,effects on cell cycle profile,caspase-3 mediated apoptosis and FAK inhibition

A series of novel benzotriazole N-acylarylhydrazone hybrids was synthesized according fragment-based design strategy. All the synthesized compounds were evaluated for their anticancer activity against 60 human tumor cell lines by NCI (USA). Five compounds: 3d, 3e, 3f, 3o and 3q exhibited significant to potent anticancer activity at low concentrations. Compound 3q showed the most prominent broad-spectrum anticancer activity against 34 tumor cell lines, with mean growth inhibition percent of 45.80%. It exerted the highest potency against colon HT-29 cell line, with cell growth inhibition 86.86%. All leukemia cell lines were highly sensitive to compound 3q. Additionally, compound 3q demonstrated lethal activity to MDA-MB-435 belonging melanoma. Compound 3e exhibited the highest anticancer activity against leukemic CCRF-CEM and HL-60(TB) cell lines, with cell growth inhibition 86.69% and 86.42%, respectively. Moreover, it exerted marked potency against ovarian OVCAR-3 cancer cell line, with cell growth inhibition 78.24%. Four compounds: 3d, 3e, 3f and 3q were further studied through determination of IC₅₀ values against the most sensitive cancer cell lines. The four compounds exhibited highly potent anticancer activity against ovarian cancer OVCAR-3 and leukemia HL-60 (TB) cell lines, with IC₅₀ values in nano-molar range between 25 and 130 nM. They showed 18–2.3 folds more potent anticancer activity than doxorubicin. The most prominent compound was 3e, (IC₅₀ values 29 and 25 nM against OVCAR-3 and HL-60 (TB) cell lines, respectively), representing 10 and 18 folds more potency than doxorubicin. The anti-proliferative activity of these four compounds appeared to correlate well with their ability to inhibit FAK at nano-molar range between 44.6 and 80.75 nM. Compound 3e was a potent, inhibitor of FAK and Pyk2 activity with IC₅₀ values of 44.6 and 70.19 nM, respectively. It was 1.6 fold less potent for Pyk2 than FAK. Additionally, it displayed inhibition in cell based assay measuring phosphorylated-FAK (IC₅₀ = 32.72 nM). Inhibition of FAK enzyme led to a significant increase in the level of active caspase-3, compared to control (11.35 folds), accumulation of cells in pre-G1 phase and annexin-V and propidium iodide staining in addition to cell cycle arrest at G2/M phase indicating that cell death proceeded through an apoptotic mechanism.     

Activity of three cytotoxic isoflavonoids from Erythrina excelsa and Erythrina senegalensis (neobavaisoflavone,sigmoidin H and isoneorautenol) toward multi-factorial drug resistant cancer cells

IntroductionResistance of cancer cells to chemotherapy has become a worldwide concern. Naturally occuring isoflavonoids possess a variety of biological activities including anti-cancer effects. The present study was aimed at investigating the cytotoxicity and the modes of action of three naturally occuring isoflavonoids, neobavaisoflavone (1), sigmoidin H (2) and a pterocarpan that is a special type of isoflavonoid, isoneorautenol (3) against a panel of nine cancer cell lines, including various sensitive and drug-resistant phenotypes.MethodsThe cytotoxicity of the compounds was determined using a resazurin reduction assay, whereas the caspase-Glo assay was used to detect the activation of caspases 3/7, caspase 8 and caspase 9 in cells treated with compounds 3. Flow cytometry was used for cell cycle analysis and detection of apoptotic cells, analysis of mitochondrial membrane potential (MMP) as well as measurement of reactive oxygen species (ROS).ResultsCompounds 3 showed significant cytotoxicity toward sensitive and drug-resistant cancer cell lines. Compounds 1 and 2 were selectively active, and IC50 values below 115 μM were obtained on 6/9 and 4/9 cell lines respectively with values ranging from 42.93 μM (toward CCRF-CEM cells) to 114.64 μM [against HCT116 (p53^+/+) cells] for 1 and 25.59 μM (toward U87MG) to 110.51 μM [against HCT116 (p53^+/+) cells] for 2. IC50 values ranging from 2.67 μM (against MDA-MB 237BCRP cells) to 21.84 (toward U87MG) were measured for compound 3 and between 0.20 μM (toward CCRF-CEM cells) and 195.12 μM (toward CEM/ADR5000 cells) for doxorubicin as control drug. BCRP-transfected MDA-MB-231 cells, HCT116 (p53^+/+) and U87MG.ΔEGFR cells were hypersensitive (collateral sensitive) to compound 3 as compared to their counterpart cell lines. Compound 3 induced apoptosis in CCRF-CEM cells via activation of caspases 3/7, 8 and 9 as well as the loss of MMP and increased ROS production.ConclusionsThe cytotoxicity of the studied isoflavonoids and especially the pterocarpan 3 deserve more detailed exploration in the future to develop novel anticancer drugs against sensitive and otherwise drug-resistant phenotypes.     

The effects of MAPK inhibitors on antimycin A-treated Calu-6 lung cancer cells in relation to cell growth, reactive oxygen species, and glutathione

Antimycin A (AMA) inhibits succinate oxidase, NADH oxidase, and mitochondrial electron transport chain between cytochrome b and c. We recently demonstrated that AMA inhibited the growth of Calu-6 lung cancer cells through apoptosis. Here, we investigated the effects of AMA and/or MAPK inhibitors on Calu-6 lung cancer cells in relation to cell growth, cell death, reactive oxygen species (ROS), and GSH levels. Treatment with AMA inhibited the growth of Calu-6 cells at 72 h. AMA-induced apoptosis was accompanied by the loss of mitochondrial membrane potential (MMP; ΔΨ_m). While ROS were decreased in AMA-treated Calu-6 cells, O ₂ ^?? among ROS was increased. AMA also induced GSH depletion in Calu-6 cells. Treatment with MEK inhibitor intensified cell death, MMP (ΔΨ_m) loss, and GSH depletion in AMA-treated Calu-6 cells. JNK inhibitor also increased cell death, MMP (ΔΨ_m) loss, and ROS levels in these cells. Treatment with p38 inhibitor magnified cell growth inhibition by AMA and increased cell death, MMP (ΔΨ_m) loss, ROS level, and GSH depletion in AMA-treated cells. Conclusively, all the MAPK inhibitors slightly intensified cell death in AMA-treated Calu-6 cells. The changes of ROS and GSH by AMA and/or MAPK inhibitors were in part involved in cell growth and death in Calu-6 cells.     

Novel coumarin-6-sulfonamides as apoptotic anti-proliferative agents: synthesis,in vitro biological evaluation,and QSAR studies

Herein, we report the synthesis of different novel sets of coumarin-6-sulfonamide derivatives bearing different functionalities (4a, b, 8a–d, 11a–d, 13a, b, and 15a–c), and in vitro evaluation of their growth inhibitory activity towards the proliferation of three cancer cell lines; HepG2 (hepatocellular carcinoma), MCF-7 (breast cancer), and Caco-2 (colon cancer). HepG2 cells were the most sensitive cells to the influence of the target coumarins. Compounds 13a and 15a emerged as the most active members against HepG2 cells (IC₅₀?=?3.48?±?0.28 and 5.03?±?0.39?µM, respectively). Compounds 13a and 15a were able to induce apoptosis in HepG2 cells, as assured by the upregulation of the Bax and downregulation of the Bcl-2, besides boosting caspase-3 levels. Besides, compound 13a induced a significant increase in the percentage of cells at Pre-G1 by 6.4-folds, with concurrent significant arrest in the G2-M phase by 5.4-folds compared to control. Also, 13a displayed significant increase in the percentage of annexin V-FITC positive apoptotic cells from 1.75–13.76%. Moreover, QSAR models were established to explore the structural requirements controlling the anti-proliferative activities.     

The changes of reactive oxygen species and glutathione by MG132, a proteasome inhibitor affect As4.1 juxtaglomerular cell growth and death

The proteasome inhibitor MG132 has been shown to induce apoptotic cell death through the formation of reactive oxygen species (ROS). Here, we evaluated the effects of MG132 on the growth and death of As4.1 juxtaglomerular cells in relation to ROS and glutathione (GSH) levels. MG132 inhibited the growth of As4.1 cells with an IC₅₀ of approximately 0.3–0.4 μM at 48 h and induced cell death, which was accompanied by the loss of mitochondrial membrane potential (MMP; ΔΨ_m), Bcl-2 decrease, activation of caspase-3 and -8, and PARP cleavage. MG132 increased intracellular ROS levels including O₂^? and GSH depleted cell numbers. N-acetyl cysteine (NAC, a well-known antioxidant) significantly decreased ROS level and GSH depleted cell numbers in MG132-treated As4.1 cells, along with the prevention of cell growth inhibition, cell death and MMP (ΔΨ_m) loss. NAC also decreased the caspase-3 activity of MG132. l-Buthionine sulfoximine (BSO; an inhibitor of GSH synthesis) or diethyldithiocarbamate (DDC; an inhibitor of Cu/Zn-SOD) did not affect cell growth, death, ROS and GSH levels in MG132-treated As4.1 cells. Conclusively, MG132 reduced the growth of As4.1 cells via apoptosis. The changes of ROS and GSH by MG132 were involved in As4.1 cell growth and death.     

Abieslactone Induces Cell Cycle Arrest and Apoptosis in Human Hepatocellular Carcinomas through the Mitochondrial Pathway and the Generation of Reactive Oxygen Species

Abieslactone is a triterpenoid lactone isolated from Abies plants. Previous studies have demonstrated that its derivative abiesenonic acid methyl ester possesses anti-tumor-promoting activity in vitro and in vivo. In the present study, cell viability assay demonstrated that abieslactone had selective cytotoxicity against human hepatoma cell lines. Immunostaining experiments revealed that abieslactone induced HepG2 and SMMC7721 cell apoptosis. Flow cytometry and western blot analysis showed that the apoptosis was associated with cell cycle arrest during the G₁ phase, up-regulation of p53 and p21, and down-regulation of CDK2 and cyclin D1. Furthermore, our results revealed that induction of apoptosis through a mitochondrial pathway led to upregulation of Bax, down-regulation of Bcl-2, mitochondrial release of cytochrome c, reduction of mitochondrial membrane potential (MMP), and activation of caspase cascades (Casp-9 and -3). Activation of caspase cascades also resulted in the cleavage of PARP fragment. Involvement of the caspase apoptosis pathway was confirmed using caspase inhibitor Z-VAD-FMK pretreatment. Recent studies have shown that ROS is upstream of Akt signal in mitochondria-mediated hepatoma cell apoptosis. Our results showed that the accumulation of ROS was detected in HepG2 cells when treated with abieslactone, and ROS scavenger partly blocked the effects of abieslactone-induced HepG2 cell death. In addition, inactivation of total and phosphorylated Akt activities was found to be involved in abieslactone-induced HepG2 cell apoptosis. Therefore, our findings suggested that abieslactone induced G₁ cell cycle arrest and caspase-dependent apoptosis via the mitochondrial pathway and the ROS/Akt pathway in HepG2 cells.     

Synthesis and characterisation of (Z)-styrylbenzene derivatives as potential selective anticancer agents

To identify anticancer agents with high potency and low toxicity, a series of (Z)-styrylbenzene derivatives were synthesised and evaluated for anticancer activities using a panel of nine cancer cell lines and two noncancerous cell lines. Most derivatives exhibited significant anti-proliferative activities against five cancer cell lines, including MGC-803 and BEL-7402. (Z)-3-(p-Tolyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile (6h) showed a strong inhibitory effect on MGC-803 cells (IC₅₀?50?50 value of 6h in L-02 cells was 10,000-fold higher than in MGC-803 cells. Compound 6h inhibited proliferation of BEL-7402 cells by arresting at the G2/M phase through up-regulation of cyclin B1 expression, down-regulation of cyclin A and D1 expression, and induction of apoptosis. In addition, 6h inhibited the migration of BEL-7402 cells and the formation of cell colonies.     

Synthesis and bioevaluation study of novel N-methylpicolinamide and thienopyrimidine derivatives as selectivity c-Met kinase inhibitors

Four series of N-methylpicolinamide moiety and thienopyrimidine moiety bearing pyridazinone were designed and synthesized and evaluated for the IC₅₀ values against three cancer cell lines (A549, HepG2 and MCF-7) and some selected compounds were further evaluated for the activity against c-Met, Flt-3, VEGFR-2, c-Kit and EGFR kinases. Three compounds (35, 39 and 43) showed more active than positive control Foretinib against A549, HepG2 and MCF-7 cell lines. The most promising compound 43 showed superior activity against A549, HepG2 and MCF-7, with the IC₅₀ values of 0.58?±?0.15?µM, 0.47?±?0.06?µM and 0.74?±?0.12?µM, which were 3.73–5.39-fold more activity than Foretinib, respectively. The experiments of enzyme-based showed that 43 restrain the c-Met selectively, with the IC₅₀ values of 16?nM, which showed equal activity to Foretinib (14?nM) and better than the compound 5 (90?nM). Moreover, AO and Annexin V/PI staining and docking studies were carried out.     

Study of the cytotoxic activity of Styrax camporum extract and its chemical markers,egonol and homoegonol

The benzofuran lignans egonol and homoegonol are found in all species of the genus Styrax. Since natural products are important sources of new anticancer drugs, this study evaluated the cytotoxic activity of a hydroalcoholic extract of the stems of S. camporum (SCHE) and their chemical markers, egonol (EG) and homoegonol (HE), against different tumor cell lines (B16F10, MCF-7, HeLa, HepG2, and MO59J). A normal human cell line (GM07492A) was included. Cytotoxic activity was evaluated at different treatment times (24, 48 and 72 h) using the XTT assay. More effective results were observed after 72 h of treatment. The lowest IC₅₀ values were found for the HepG2 cell line, ranging from 11.2 to 55.0 µg/mL. The combination of EG and HE exerted higher cytotoxic activity than SCHE or treatment with either lignan alone, with the lowest IC₅₀ (13.31 µg/mL) being observed for the MCF-7 line. Furthermore, treatment with these lignans was significantly more cytotoxic for some tumor cell lines compared to the normal cell line, GM07492A, indicating selectivity. These results suggest that these lignans may be used to treat cancer without affecting normal cells.     

Medicarpin and millepurpan,two flavonoids isolated from Medicago sativa,induce apoptosis and overcome multidrug resistance in leukemia P388 cells

BackgroundHigh consumption of flavonoids has been associated with a decrease risk of cancer. Alfalfa (Medicago sativa) leaves have been widely used in traditional medicine and is currently used as a dietary supplement because of their high nutrient content. We previously reported the cytotoxic activity of alfalfa leaf extracts against several sensitive and multidrug resistant tumor cell lines.Hypothesis/purposeWe aimed to determine whether medicarpin and millepurpan, two isoflavonoids isolated from alfalfa leaves, may have pro-apoptotic effects against drug-sensitive (P388) and multidrug resistant P388 leukemia cells (P388/DOX).Study design/methodsCells were incubated with medicarpin or millepurpan for the appropriate time. Cell viability was assessed by the MTT assay. DNA fragmentation was analyzed by agarose gel electrophoresis. Cell cycle analysis was realized by flow cytometry technics. Caspases 3 and 9 activities were measured using Promega caspACE assay kits. Proteins and genes expression were visualized respectively by western-blot using specific antibodies and RT-PCR assay.ResultsP-glycoprotein-expressing P388/DOX cells did not show resistance to medicarpin (IC₅₀ ≈ 90 µM for P388 and P388/DOX cells) and millepurpan (IC₅₀ = 54 µM and 69 µM for P388 and P388/DOX cells, respectively). Treatment with medicarpin or millepurpan triggered apoptosis in sensitive as well as multidrug resistant P388 cells. These effects were mediated through the mitochondrial pathway by modifying the balance pro/anti-apoptotic proteins. While 3 µM doxorubicin alone could not induce cell death in P388/DOX cells, concomitant treatment with doxorubicin and subtoxic concentration of medicarpin or millepurpan restored the pro-apoptotic cascade. Each compound increased sensitivity of P388/DOX cells to doxorubicin whereas they had no effect in sensitive P388 cells. Vinblastine cytotoxicity was also enhanced in P388/DOX cells (IC₅₀ = 210 nM to 23 and 25 nM with medicarpin and millepurpan, respectively). This improved sensitivity was mediated by an increased uptake of doxorubicin in P388/DOX cells expressing P-gp. P-gp expression was not altered by exposure to medicarpin and millepurpan.ConclusionThese data indicate that medicarpin and millepurpan possess pro-apoptotic properties and potentiate the cytotoxicity of chemotherapy drugs in multidrug resistant P388 leukemia cells by modulating P-gp-mediated efflux of drugs. These flavonoids may be used as chemopreventive agents or as sensitizer to enhance cytotoxicity of chemotherapy drugs in multidrug resistant cancer cells.