Proliferation Inhibitory Activity of Quinones from Blaps rynchopetera Defense Secretion on Colorectal Tumor Cells / 中国结合医学杂志

OBJECTIVE@#To explore the proliferation inhibitory effect of quinones from Blaps rynchopetera defense secretion on colorectal tumor cell lines.@*METHODS@#Human colorectal cancer cell HT-29, human colorectal adenocarcinoma cell Caco-2 and normal human colon epithelial cell CCD841 were chosen for the evaluation of inhibitory activity of the main quinones of B. rynchopetera defense secretion, including methyl p-benzoquinone (MBQ), ethyl p-benzoquinone (EBQ), and methyl hydroquinone (MHQ), through methyl thiazolyl tetrazolium assay. The tumor-related factors, cell cycles, related gene expressions and protein levels were detected by enzyme-linked immunosorbent assy, flow cytometry, RT-polymerase chain reaction and Western blot, respectively.@*RESULTS@#MBQ, EBQ, and MHQ could significantly inhibit the proliferation of Caco-2, with half maximal inhibitory concentration (IC50) values of 7.04 ± 0.88, 10.92 ± 0.32, 9.35 ± 0.83, HT-29, with IC50 values of 14.90 ± 2.71, 20.50 ± 6.37, 13.90 ± 1.30, and CCD841, with IC50 values of 11.40 ± 0.68, 7.02 ± 0.44 and 7.83 ± 0.05 µg/mL, respectively. Tested quinones can reduce the expression of tumor-related factors tumor necrosis factor α, interleukin (IL)-10, and IL-6 in HT-29 cells, selectively promote apoptosis, and regulate the cell cycle which can reduce the proportion of cells in the G1 phase and increase the proportion of the S phase. Meanwhile, tested quinones could up-regulate mRNA and protein expression of GSK-3β and APC, while down-regulate that of β-catenin, Frizzled1, c-Myc, and CyclinD1 in the Wnt/β-catenin pathway of HT-29 cells.@*CONCLUSION@#Quinones from B. rynchopetera defense secretion could inhibit the proliferation of colorectal tumor cells and reduce the expression of related factors, which would be functioned by regulating cell cycle, selectively promoting apoptosis, and affecting Wnt/β-catenin pathway-related mRNA and protein expressions.

Dysideanones F-G and dysiherbols D-E, unusual sesquiterpene quinones with rearranged skeletons from the marine sponge Dysidea avara / 中国天然药物

Four new sesquiterpene quinone meroterpenoids, dysideanones F-G (1-2) and dysiherbols D-E (3-4), were isolated from the marine sponge Dysidea avara collected from the South China Sea. The new structures were elucidated by extensive analysis of spectroscopic data including HR-MS and 1D and 2D NMR spectra, and their absolute configurations were assigned by single-crystal X-ray diffraction and ECD calculations. Anti-inflammatory evaluation showed that dysiherbols D-E (3-4) exhibited moderate inhibitory activity on TNF-α-induced NF-κB activation in human HEK-293T cells with IC50 values of 10.2 and 8.6 μmol·L-1, respectively.

Synthesis and antiproliferative evaluation of new isomeric ellipticine quinones / Síntesis y evaluación de la actividad antiproliferativa de nuevas elipticinquinonas isomericas

The synthesis of new isomeric ellipticine quinones 3a-c and their in vitro antiproliferative activities on cancer cell lines is reported. The designed N-heterocyclic quinones 3a-c were synthesized through a three step sequence which involves: a) one-pot preparation of 4-methoxycarbonyl-3,4-dimethylisoquinoline-5,8-quinone 1 from 2,5-dihydroxyacetophenone, methyl aminocrotonate and silver (II) oxide; b) regioselective amination of 1 with arylamines to give aminoquinones 2a-c and c) palladium-catalyzed intramolecular oxidative coupling of 7-aminoisoquinoline-5,8-quinones 2a-c. The in vitro antiproliferative activity of the new angular quinones was evaluated againts one normal cell line (lung fibroblasts) and gastric, lung and bladder cancer cell lines in 72-h drug exposure assays. The new compounds displayed similar or higher antiproliferative activity with respect to their quinone precursors 2a-c. The isomeric ellipticine quinone 2b appears as the more active member on bladder cancer cell line (IC50: 2.4 uM), comparable to etoposide used as anticancer reference drug...

Se describe la síntesis de las nuevas quinonas 3a-c, isoméricas de elipticina, y sus actividades antiproliferativas in vitro en líneas de células de cáncer. Las quinonas N-heterocíclicas 3a-c se sintetizaron a través de una secuencia que involucra: a) preparación de 4- metoxicarbonil-3,4-dimetlisoquinolin-5,8-quinone 1 a partir de 2,5-dihidroxiacetofenona, aminocrotonato de metilo y óxido de plata (I); b) aminación regioselectiva de 1 con arilaminas para producir las aminoquinonas 2a-c y c) acoplamiento oxidante intramolecular de 7- aminoisoquinolin-5,8-quinonas 2a-c catalizado con paladio. La actividad antiproliferative in vitro de los nuevos compuestos fue evaluada en una línea celular normal (fibroblastos de pulmón) y líneas de células de cáncer gástrico, pulmón y vejiga en ensayos de exposición de 72 horas a la droga. Las quinonas 3a-c exhiben interesantes propiedades antiproliferativas destacando la elipticinquinona isomérica 2b en células de cáncer de vejiga (IC50: 2.4 uM) comparado con etopósido usada como droga anticancer de referencia. Los nuevos compuestos mostraron actividades antiproliferativa similar o mayor respecto de las correspondientes quinonas precursoras 2a-c. La elipticin quinona isomérica 2b corresponde al miembro más activo en células de câncer de vejiga (IC50: 2.4 uM), comparable a la del etopósido, usada como droga anticáncer de referencia...

Genotoxic, neurotoxic and neuroprotective activities of apomorphine and its oxidized derivative 8-oxo-apomorphine

Apomorphine is a dopamine receptor agonist proposed to be a neuroprotective agent in the treatment of patients with Parkinson's disease. Both in vivo and in vitro studies have shown that apomorphine displays both antioxidant and pro-oxidant actions, and might have either neuroprotective or neurotoxic effects on the central nervous system. Some of the neurotoxic effects of apomorphine are mediated by its oxidation derivatives. In the present review, we discuss recent studies from our laboratory in which the molecular, cellular and neurobehavioral effects of apomorphine and its oxidized derivative, 8-oxo-apomorphine-semiquinone (8-OASQ), were evaluated in different experimental models, i.e., in vitro genotoxicity in Salmonella/microsome assay and WP2 Mutoxitest, sensitivity assay in Saccharomyces cerevisiae, neurobehavioral procedures (inhibition avoidance task, open field behavior, and habituation) in rats, stereotyped behavior in mice, and Comet assay and oxidative stress analyses in mouse brain. Our results show that apomorphine and 8-OASQ induce differential mutagenic, neurochemical and neurobehavioral effects. 8-OASQ displays cytotoxic effects and oxidative and frameshift mutagenic activities, while apomorphine shows antimutagenic and antioxidant effects in vitro. 8-OASQ induces a significant increase of DNA damage in mouse brain tissue. Both apomorphine and 8-OASQ impair memory for aversive training in rats, although the two drugs showed a different dose-response pattern. 8-OASQ fails to induce stereotyped behaviors in mice. The implications of these findings are discussed in the light of evidence from studies by other groups. We propose that the neuroprotective and neurotoxic effects of dopamine agonists might be mediated, in part, by their oxidized metabolites.

Involvement of throm box aneA2 and tyrosine kinase in the synergistic interaction of platelet activating factor and calcium ionophore A23187 in human platelet aggregation

The present study was carried out to examine the mechanisms of the synergistic interaction of PAF and A23187 mediated platelet aggregation. We found that platelet aggregation mediated by subthreshold concentrations of PAF (5 nM) and A23187 (1 micrometer) was inhibited by PAF receptor blocker (WEB 2086, IC50=0.65 micrometer) and calcium channel blockers, diltiazem (IC50=13 micrometer) and verapamil (IC50=18 micrometer). Pretreatment of platelets with PAF and A23187 induced rise in intracellular calcium and this effect was also blocked by verapamil. While examining the role of the down stream signaling pathways, we found that platelet aggregation induced by the co-addition of PAF and A23187 was also inhibited by low concentrations of phospholipase C (PLC) inhibitor (U73122; IC50 = 10 micrometer), a cyclooxygenase inhibitor (indomethacin; IC50=0.2 micrometer) and inhibitor of TLCK, herbimycin A with IC50 value of 5 micrometer. The effect was also inhibited by a specific TXA2 receptor antagonist, SQ 29548 with very low IC50 value of 0.05 micrometer. However, the inhibitors of MAP kinase, PD98059 and protein kinase C, chelerythrine had no effect on PAF and A23187-induced platelet aggregation. These data suggest that the synergism between PAF and A23187 in platelet aggregation involves activation of thromboxane and tyrosine kinase pathways.

Role of Ras/ERK-dependent pathway in the erythroid differentiation of K562 cells

The chronic myelogenous leukemic K562 cell line carrying Bcr-Abl tyrosine kinase is considered as pluripotent hematopoietic progenitor cells expressing markers for erythroid, granulocytic, monocytic, and megakaryocytic lineages. Here we investigated the signaling modulations required for induction of erythroid differentiation of K562 cells. When the K562 cells were treated with herbimycin A (an inhibitor of protein tyrosine kinase), ras antisense oligonucleotide, and PD98059 (a specific inhibitor of MEK), inhibition of ERK/MAPK activity and cell growth, and induction of erythroid differentiation were observed. The ras mutant, pZIPRas61leu-transfected cells, K562-Ras61leu, have shown a markedly decreased cell proliferation rate with approximately 2-fold doubling time, compared with the parental K562 cells, and about 60% of these cells have shown the phenotype of erythroid differentiation. In addition, herbimycin A inhibited the growth rate and increased the erythroid differentiation, but did not affect the elevated activity of ERK/MAPK in the K562-Ras61leu cells. On the other hand, effects of PD98059 on the growth and differentiation of K562-Ras61leu cells were biphasic. At low concentration of PD98059, which inhibited the elevated activity of ERK/MAPK to the level of parental cells, the growth rate increased and the erythroid differentiation decreased slightly, and at high concentration of PD98059, which inhibited the elevated activity of ERK/MAPK below that of the parental cells, the growth rate turned down and the erythroid differentiation was restored to the untreated control level. Taken together, these results suggest that an appropriate activity of ERK/MAPK is required to maintain the rapid growth and transformed phenotype of K562 cells.

Possible interaction of potassium embelate, a putative analgesic agent, with opiate receptors.

The in vivo studies have been carried out in the rat brain for characterization of binding sites for potassium embelate (ex: Embelia ribes) a potent centrally acting analgesic compound. The results indicate that mixed mu and kappa binding sites in the brain may be involved in the analgesic action of this compound.

Inhibición del crecimiento y la síntesis de DNA y formación de anión superóxido por quinona-iminas en Trypanosoma cruzi / Quinone-imine inhibition of growth and DNA synthesis, and induction of superoxide anion generation in Trypanosoma cruzi

Se ensayaron cuatro aminodisoxazolil -1, 2, -naftoquinosa sobre el crecimiento, la síntesis de DNA y la producción de anión superóxido por Trypanosoma cruzi. Las quinona-iminas a) inhibieron el crecimiento y la síntesis de DNA; b) aumentaron el consumo de oxígeno de los epimastigotes y c) estimularon la formación de anión superóxido por los epimastigotes enteros y las fracciones mitocondrial y microsomal. La antimicina, un inhibidor, un inhibidor del transporte de electrones mitocondrial, intensificó la acción de las quinona-iminas sobre la respiración y la formación de anión superóxido. Reacciones redox demostrables espectroscópicamente corroboraron la intervención de las quinoma-iminas en la producción de oxiradicales por T. cruzi

Efecto de quinonas y nitrofuranos sobre Trypanosoma mega y Crithidia fasciculata / Effect of quinones and nitrofurans on Trypanosoma mega and Crithidia fasciculata

La valoración in vitro de tripanocidas activos sobre Trypanosoma cruzi es el primer paso para el desarrollo de nuevos agentes terapéuticos contra la enfermedad de Chagas. Para verificar si una información equivalente puede lograrse con organismos no patógenos, se estudió la acción de varios tripanocidas de t. cruzi sobre T. mega y Crithidia fasciculada. Las drogas se ensayaron sobre el crecimiento de los protozoarios que se midió por la turbiedad de la suspensión celular en medio de cultivo líquido. Una serie de quinonas, incluyendo quinonas lipofílicas, lapachonas, quinina-iminas, benzoquinonas, un quinol (miconidina) y nitrofuranos (nifurtimox y análogos derivados del grupo (5-nitro-2-furfurilideno)-amino (grupo NF) inhibieron el crecimiento de los organismos, especialmente el de T. mega, con I50 menores de 5 micronM, para los compuestos mas activos. La sensibilidad de T. mega fue similar a la de T. cruzi y significativamente mayor que la de C. fasciculata. El cultivo de muestras de T. mega, preincubados con las mismas drogas,d emostró efectos irreversibles con los NF-derivados del pirazol, imidazol, indazol y benzimidazol pero no con el nifurtimox. En iguales condiciones, C. fasciculata fue afectada solamente por la ß-lapachona y una naftoquinona-imina. Estos resultados califican a T. mega como un modelo adecuado para el ensayo inicial de quimioterápicos anti-chagásicos, como lo son C. fasciculata y T. brucei para los tripanosomas africanos