Pharmacogenomic Characterization of Cytotoxic Compounds from <i>Salvia officinalis</i> in Cancer Cells

<i>Salvia officinalis</i> is used as a dietary supplement with diverse medicinal activity (e.g. antidiabetic and antiatherosclerotic effects). The plant also exerts profound cytotoxicity toward cancer cells. Here, we investigated possible modes of action to explain its activity toward drug-resistant tumor cells. Log₁₀IC₅₀ values of two constituents of <i>S. officinalis</i> (ursolic acid, pomolic acid) were correlated to the expression of ATP-binding cassette (ABC) transporters (P-glycoprotein/<i>ABCB1/MDR1</i>, MRP1/<i>ABCC1</i>, BCRP/<i>ABCG2</i>) and epidermal growth factor receptor (<i>EGFR</i>) or mutations in <i>RAS</i> oncogenes and the tumor suppressor gene <i>TP53</i> of the NCI panel of cell lines. Gene expression profiles predicting sensitivity and resistance of tumor cells to these compounds were determined by microarray-based mRNA expressions, COMPARE, and hierarchical cluster analyses. Furthermore, the binding of both plant acids to key molecules of the NF-κB pathway (NF-κB, I-κB, NEMO) was analyzed by molecular docking. Neither expression nor mutation of ABC transporters, oncogenes, or tumor suppressor genes correlated with log₁₀IC₅₀ values for ursolic acid or pomolic acid. In microarray analyses, many genes involved in signal transduction processes correlated with cellular responsiveness to these compounds. Molecular docking indicated that the two plant acids strongly bound to target proteins of the NF-κB pathway with even lower free binding energies than the known NF-κB inhibitor MG-132. They interacted more strongly with DNA-bound NF-κB than free NF-κB, pointing to inhibition of DNA binding by these compounds. In conclusion, the lack of cross-resistance to classical drug resistance mechanisms (ABC-transporters, oncogenes, tumor suppressors) may indicate a promising role of the both plant acids for cancer chemotherapy. Genes involved in signal transduction may contribute to the sensitivity or resistance of tumor cells to ursolic and pomolic acids. Ursolic and pomolic acid may target different steps of the NF-κB pathway to inhibit NF-κB-mediated functions

ART sensitizes malignant T cells to Doxorubicin-induced apoptosis.

<p>Jurkat (A) and CEM (B) cells were treated with combinations of different doses of ART and Doxorubicin for 24 h as indicated. The drugs were added at the same time. Apoptotic cell death was quantified by DNA fragmentation in triplicates. Results are representative of three independent experiments. The p value was determined by a two-way ANOVA test with factors Dox-, ART-, and their interaction. For Jurkat cells, the p values are p<0.0001 for Dox- and ART-treatment and p = 0.0006 for the combination treatment. For CEM cells, the p values are p<0.0001 for Dox-, ART- as well as the combination treatment.</p

<i>Daphne striata</i> Tratt. and <i>D. mezereum</i> L.: a study of anti-proliferative activity towards human cancer cells and antioxidant properties

<p>In this study, we investigated for the first time the anti-proliferative and antioxidant properties of <i>D. mezereum</i> and <i>D. striata</i>. The aerial parts were extracted by maceration with <i>n</i>-hexane, dichloromethane, and methanol. MPLC, GC, and GC-MS were used for the phytochemical study. The anti-proliferative activity was tested against MCF-7, A549, LNCaP, ACHN, and C32 cancer human cells. The antioxidant activity was measured by employing β-carotene bleaching, ABTS, DPPH, and FRAP tests. The Relative Antioxidant Capacity Index (RACI) was applied from the perspective of statistics. <i>D. mezereum</i> dichloromethane extract showed a remarkable anti-proliferative with an IC₅₀ of 6.08 μg/mL against LNCaP cells. Experimental data indicate that <i>Daphne</i> species have interesting anti-proliferative and antioxidant properties that deserve more investigations to develop novel antineoplastic drugs.</p

ROS mediate ART-induced apoptosis in leukemia cells.

<p>(A) Jurkat cells were treated with 4 µg/ml of ART for different times as indicated and the redox status was monitored by the oxidation-sensitive fluorescent dyes for H₂O₂. (B) CEM cells were treated with 0.5 µg/ml doses ART. After 30 min, the redox status was measured as in (A). (C) and (D) ART-induced apoptosis was blocked by the antioxidant NAC. Jurkat (C) and CEM (D) cells were treated with ART in the presence (15 mM) or absence of NAC for 24 h. Apoptotic cell death was analyzed by FSC/SSC in triplicates. Results are representative of four independent experiments.</p

ART induces Doxorubicin-resistant leukemic cells to undergo apoptosis by a mechanism different from the one induced by Doxorubicin.

<p>(A) ART induces apoptosis in Doxorubicin-resistant leukemic cells. Doxorubicin-resistant (CEM-Dox_R) and parental (CEM-parental) CEM cells were treated with either 1 µg/ml of ART or 0.5 µg/ml of Doxorubicin for 24 h. Apoptosis was determined by FSC/SSC (left panel) and DNA fragmentation (right panel). Results are representative of two independent experiments. (B) NAC inhibits ART-induced apoptosis in Doxorubicin-resistant leukemic cells. CEM-Dox_R cells were treated with different doses of ART in the presence or absence of NAC (15 mM). Apoptotic cell death was determined by DNA fragmentation in triplicates. (C) and (D) NAC does not inhibit Doxorubicin-induced apoptosis. CEM-parental (C) and Jurkat (D) cells were treated either with ART or Doxorubicin in the presence or absence of NAC. Apoptotic cell death was determined by DNA fragmentation. Results are representative of four independent experiments. The p value was determined by the statistic program of Microsoft Excel. (E) ART induces ROS generation in CEM-Dox_R cells. CEM-Dox_R cells were treated with 4 µg/ml of ART in the presence or absence of NAC (15 mM) for 30 min. The redox status was measured as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0000693#pone-0000693-g003" target="_blank">figure 3</a>. (F) Doxorubicin does not induce ROS in leukemic T cells. CEM-Dox_R, CEM-parental and Jurkat cells were treated with 0.5 µg/ml of Doxorubicin in the presence or absence of NAC for 30 min. The redox status was measured as in (E). Results are representative of three independent experiments. (G) Doxorubicin does not interfere with the redox assay. CEM cells were treated with Doxorubicin (2 µg/ml) or ART (4 µg/ml) alone or in combination for 30 min. The redox status was measured as in F.</p

ART induces apoptosis through the intrinsic (mitochondria) pathway.

<p>(A) The death receptor system is not required for ART-induced apoptosis. Jurkat cells deficient in FADD (FADD^−/−), caspas-8 (casp-8^−/−), or over-expressing Bcl-2 and parental (A3) Jurkat cells were treated with different does of ART. Apoptotic cell death was determined by FSC/SSC in triplicates. (B) ART-induced apoptosis involves caspases. Jurkat cells were treated with ART (4 µg/ml) in the presence or absence of 50 µM of pan-caspase inhibitor zVAD-fmk for 48 h. Apoptotic cell death was determined by DNA fragmentation in triplicates. (C) ART induces cytochrome c release and activation of caspase-2, 3 and 9. CEM leukemia cells were treated with 1 µg/ml ART for different times as indicated. Cell lysates were subjected to Western blotting with antibodies against cytochrome c, caspase-2, 3, 8, 9, PARP, and control antibodies against tubulin. Data are representative of three independent experiments.</p

Medicinal plants and animals used in Vietnamese medicine and cytotoxicity of hexane, water or methanol extracts (10 μg/ml) to CCRF-CEM leukemia cells

<p><b>Copyright information:</b></p><p>Taken from "Molecular biology of cantharidin in cancer cells"</p><p>http://www.cmjournal.org/content/2/1/8</p><p>Chinese Medicine 2007;2():8-8.</p><p>Published online 4 Jul 2007</p><p>PMCID:PMC1934358.</p><p></p> (1) (whole beetles), (2) (roots), (3) (roots, branches), (4) (fruits), (5) (roots), (6) C.A.Mey., (7) (rhizoma), (8) Maxim (kernels), (9) (roots). Growth inhibitory activity was measured using a growth inhibition assay [16]

Cytotoxicity of an unprecedented brominated oleanolide and a new furoceramide from the Cameroonian spice, <i>Echinops giganteus</i>

<p>A preliminary study on <i>Echinops giganteus</i> (Asteraceae) showed that the methanolic extract has interesting cytotoxicities against a panel of cancer cell lines. From this extract, a lignan, a flavonoid and a polyacetylenic thiophene identified were three times less cytotoxic than the extract. In the search of the metabolites responsible for the bioactivity, a new harvested <i>E. giganteus</i> was subjected to a phytochemical study using chromatographic methods. In the course of the work, two new compounds: a brominated oleanolide (<b>1</b>) and a tetrahydrofurano-ceramide (<b>2</b>) were obtained along with β-amyrin acetate (<b>3</b>), 2-(penta-1,3-diynyl)-5-(4-hydroxybut-1-ynyl)-thiophene (<b>4</b>), 2-(penta-1,3-diynyl)-5-(3,4-dihydroxybut-1-ynyl)-thiophene (<b>5</b>) and 4-hydroxy-2,6-di-(3′,4′-dimethoxyphenyl)-3,7-dioxabicyclo-(3.3.0)octane (<b>6</b>). Their structures were determined on the basis of NMR spectroscopy and mass spectrometry data in conjunction with those reported in the literature. The cytotoxicity of <b>1</b>, <b>2</b> and <b>5</b> was evaluated by employing resazurin assay against a panel of cancer cell lines with IC₅₀ values in range 6.12 ± 0.46–46.96 ± 3.61 μM.</p

Factors Determining Sensitivity and Resistance of Tumor Cells to Arsenic Trioxide

<div><p>Previously, arsenic trioxide showed impressive regression rates of acute promyelocytic leukemia. Here, we investigated molecular determinants of sensitivity and resistance of cell lines of different tumor types towards arsenic trioxide. Arsenic trioxide was the most cytotoxic compound among 8 arsenicals investigated in the NCI cell line panel. We correlated transcriptome-wide microarray-based mRNA expression to the IC₅₀ values for arsenic trioxide by bioinformatic approaches (COMPARE and hierarchical cluster analyses, Ingenuity signaling pathway analysis). Among the identified pathways were signaling routes for p53, integrin-linked kinase, and actin cytoskeleton. Genes from these pathways significantly predicted cellular response to arsenic trioxide. Then, we analyzed whether classical drug resistance factors may also play a role for arsenic trioxide. Cell lines transfected with cDNAs for catalase, thioredoxin, or the anti-apoptotic bcl-2 gene were more resistant to arsenic trioxide than mock vector transfected cells. Multidrug-resistant cells overexpressing the <em>MDR1</em>, <em>MRP1</em> or <em>BCRP</em> genes were not cross-resistant to arsenic trioxide. Our approach revealed that response of tumor cells towards arsenic trioxide is multi-factorial.</p> </div

Expression of ABCB6 and ABCB7 in MCF7 (A.) and CCRF-CEM cells (B.) after treatment with artesunate.

<p>The expression after 24 hours is given in relation to the expression before treatment.</p