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Publikation
CP (cisplatin) and mesoporous silica SBA-15 (Santa Barbara amorphous 15) loaded with CP (→SBA-15|CP) were tested in vitro and in vivo against low metastatic mouse melanoma B16F1 cell line. SBA-15 only, as drug carrier, is found to be not active, while CP and SBA-15|CP revealed high cytotoxicity in lower μM range. The activity of SBA-15|CP was found similar to the activity of CP alone. Both CP and SBA-15|CP induced inhibition of cell proliferation (carboxyfluorescein succinimidyl ester - CFSE assay) along with G2/M arrest (4′,6-diamidino-2-phenylindole - DAPI assay). Apoptosis (Annexin V/ propidium iodide - PI assay), through caspase activation (apostat assay) and nitric oxide (NO) production (diacetate(4-amino-5-methylamino-2′,7′-difluorofluorescein-diacetat) - DAF FM assay), was identified as main mode of cell death. However, slight elevated autophagy (acridine orange - AO assay) was detected in treated B16F1 cells. CP and SBA-15|CP did not affect production of ROS (reactive oxygen species) in B16F1 cells. Both SBA-15|CP and CP induced in B16F1 G2 arrest and subsequent senescence. SBA-15|CP, but not CP, blocked the growth of melanoma in C57BL/6 mice. Moreover, hepato- and nephrotoxicity in SBA-15|CP treated animals were diminished in comparison to CP confirming multiply improved antitumor potential of immobilized CP. Outstandingly, SBA-15 boosted in vivo activity and diminished side effects of CP.
Publikation
Two novel triphenyltin(IV) compounds, [Ph3SnL1] (L1 = 2-(5-(4-fluorobenzylidene)-2,4-dioxotetrahydrothiazole-3-yl)propanoate (1)) and [Ph3SnL2] (L2 = 2-(5-(5-methyl-2-furfurylidene)-2,4-dioxotetrahydrothiazole-3-yl)propanoate (2)) were synthesized and characterized by FT-IR, (1H and 13C) NMR spectroscopy, mass spectrometry, and elemental microanalysis. The in vitro anticancer activity of the synthesized organotin(IV) compounds was determined against four tumor cell lines: PC-3 (prostate), HT-29 (colon), MCF-7 (breast), and HepG2 (hepatic) using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-12 diphenyltetrazolium bromide) and CV (crystal violet) assays. The IC50 values are found to be in the range from 0.11 to 0.50 μM. Compound 1 exhibits the highest activity toward PC-3 cells (IC50 = 0.115 ± 0.009 μM; CV assay). The tin and platinum uptake in PC-3 cells showed a threefold lower uptake of tin in comparison to platinum (as cisplatin). Together with its higher activity this indicates a much higher cell inhibition potential of the tin compounds (calculated to ca. 50 to 100 times). Morphological analysis suggested that the compounds induce apoptosis in PC-3 cells, and flow cytometry analysis revealed that 1 and 2 induce autophagy as well as NO (nitric oxide) production.
Publikation
Two novel Co(II) fenamato complexes containing bathocuproine (bcp), namely [Co(bcp)(flu)2] (1) and [Co(bcp)(nif)2] (2) (flu = flufenamato, nif = niflumato) were synthesized and characterized by elemental analysis, single-crystal X-ray structure analysis as well as absorption and fluorescence spectroscopy. Investigation of their molecular structure revealed that both complexes are isostructural and form analogous complex molecules, with a Co(II) atom hexacoordinated by two nitrogen atoms of bcp and four oxygen atoms of two chelate bonded flu (1) and nif (2) ligands in a distorted octahedral arrangement. Surprisingly, the results of cytotoxicity experiments on four cancer cell lines (HeLa, HT-29, PC-3 and MCF-7) have revealed that despite similar structure of the complexes, the nif complex exhibits significantly higher activity, being the most effective against the PC-3 cell line (IC50 (MTT) = 6.11 ± 1.95 μM). Further studies performed on PC-3 cell line have shown that the mechanism of the cytotoxic action of nif complex (2) might involve activation of autophagic processes and apoptosis, while for its flu analogue (1) apoptosis was detected.
Publikation
SBA-15 (Santa Barbara Amorphous 15) mesoporous silica and its functionalized form (with 3-mercaptopropyltriethoxysilane) SBA-15~SH were used as carriers for [Ru(η6-p-cymene)Cl2{Ph2P(CH2)3SPh-κP}] complex, denoted as [Ru]. Prepared mesoporous silica nanomaterials were characterized by traditional methods. Materials without [Ru] complex did not show any cytotoxic activity against melanoma B16 and B16-F10 cell lines. On the contrary, materials containing [Ru] such as SBA-15|[Ru] and SBA-15~SH|[Ru], exhibited very high activity against tested tumor cell lines, moreover with similar inhibitory potential. According to the loaded amount of the [Ru] in SBA-15|[Ru] and SBA-15~SH|[Ru] the IC50 values are 1–2μM depending on the test used, thus in comparison to [Ru] alone the activity of nanomaterials containing [Ru] are elevated 3–6 times in vitro. However, the mechanism of apoptosis induction differs for these two mesoporous silica. Unlike reference [Ru] compound and SBA-15~SH|[Ru], SBA-15|[Ru] induces high caspase activation. Discrepancy in mechanism of drugs action at intracellular level points towards an influence of functionalization as well as availability of the drug. Moreover, both SBA-15|[Ru] and SBA-15~SH|[Ru] similarly to [Ru] are declining autophagy in B16 cell line.
Publikation
Four novel gold(III) complexes of general formulae [AuCl2{(S,S)-R2eddl}]PF6 (R2eddl = O,O′-dialkyl-(S,S)-ethylenediamine-N,N′-di-2-(4-methyl)pentanoate, R = n-Pr, n-Bu, n-Pe, i-Bu; 1–4, respectively), were synthesized and characterized by elemental analysis, UV/Vis, IR, and NMR spectroscopy, as well as high resolution mass spectrometry. Density functional theory calculations pointed out that (R,R)-N,N′-configuration diastereoisomers were energetically the most favorable. Duo to high cytotoxic activity complex 3 was chosen for stability study in DMSO, no decomposition occurs within 24 h, and for the reaction with ascorbic acid in which was reduced immediately. Additionally, 3 interacts with bovine serum albumin (BSA) as proven by UV/Vis spectroscopy. In vitro antitumor activity was determined against human cervix adenocarcinoma (HeLa), human myelogenous leukemia (K562), and human melanoma (Fem-x) cancer cell lines, as well as against non-cancerous human embryonic lung fibroblast cells MRC-5. The highest activity was observed against K562 cells (IC50: 5.04–6.51 μM). Selectivity indices showed that these complexes are less toxic than cisplatin. 3 had a similar viability kinetics on HeLa cells as cisplatin. Drug accumulation studies in HeLa cells showed that the total gold uptake increased much faster than that of cisplatin pointing out that 3 more efficiently enters the cells than cisplatin. Furthermore, morphological and cell cycle analysis reveal that gold(III) complexes induced apoptosis in time- and dose-dependent manner.
Publikation
[Ru(η6-p-cym)Cl{dpa(CH2)4COOEt}][PF6] (cym = cymene; dpa = 2,2′-dipyridylamine; complex 2) was prepared and characterized by elemental analysis, IR and multinuclear NMR spectroscopy, as well as ESI-MS and X-ray structural analysis. The structural analog without a side chain [Ru(η6-p-cym)Cl(dpa)][PF6] (1) as well as 2 were investigated in vitro against 518A2, SW480, 8505C, A253 and MCF-7 cell lines. Complex 1 is active against all investigated tumor cell lines while the activity of compound 2 is limited only to caspase 3 deficient MCF-7 breast cancer cells, however, both are less active than cisplatin. As CD4+ Th cells are necessary to trigger all the immune effector mechanisms required to eliminate tumor cells, besides testing the in vitro antitumor activity of 1 and 2, the effect of ruthenium(II) complexes on the cells of the adaptive immune system have also been evaluated. Importantly, complex 1 applied in concentrations which were effective against tumor cells did not affect immune cell viability, nor did exert a general immunosuppressive effect on cytokine production. Thus, beneficial characteristics of 1 might contribute to the overall therapeutic properties of the complex.
Publikation
There is considerable evidence suggesting that jasmonates (JAs) play a role in plant resistance against abiotic stress. It is well known that in Angiosperms JAs are involved in the defense response, however there is little information about their role in Gymnosperms. Our proposal was to study the involvement of JAs in Pinus pinaster Ait. reaction to cold and water stress, and to compare the response of two populations of different provenances (Gredos and Bajo Tiétar) to these stresses. We detected 12-oxo-phytodienoic acid (OPDA), jasmonic acid (JA), and the hydroxylates 11-hydroxyjasmonate and 12-hydroxyjasmonate in foliage and shoots of P. pinaster plants. The response of the Gredos population to cold stress differed from that of Bajo Tiétar. Gredos plants showed a lower JA-basal level than Bajo Tiétar; under cold stress JA increased twofold at 72 h, while it decreased in Bajo Tiétar plants. The hydroxylates slightly increased in both populations due to cold stress treatment. Under water stress, plants from Gredos showed a remarkable JA-increase; thus the JA-response was much more prominent under water stress than under cold stress. In contrast, no change was found in JA-level in Bajo Tiétar plants under water stress. The level of JA-precursor, OPDA, was very low in control plants from Gredos and Bajo Tiétar. Under water stress OPDA increased only in plants from Bajo Tiétar. Therefore, we inform here of a different JAs-accumulation pattern after the stress treatment in P. pinaster from two provenances, and suggest a possible correlation with adaptations to diverse ecological conditions.
Publikation
Jasmonic acid biosynthesis occurs in leaves and there is also evidence of a similar pathway in roots. The expression of lipoxygenase, allene oxide cyclase and low amounts of transcripts of allene oxide synthase in tomato roots indicates that some steps of the jasmonate synthesis may occur in these organs. Thus, the aim of the present work was to study the jasmonate and octadecanoid occurrence in tomato roots using isolated cultures of hairy roots. These were obtained by the transformation of cv. Pera roots with Agrobacterium rhyzogenes. Also we investigated the effect of NaCl stress on the endogenous levels of these compounds. Jasmonic acid, 12-oxophytodienoic acid and their methylated derivatives, as well as a jasmonate-isoleucine conjugate, were present in control hairy roots of 30 d of culture. The 12-oxophytodienoic acid and its methylated derivative showed higher levels than jasmonic acid and its methylated form, although the content of the conjugate was the same as that of jasmonic acid. After salinization of hairy roots for 14, 20 and 30 d, free jasmonates and octadecanoids were measured. Fourteen days after salt treatment, increased levels of these compounds were found, jasmonic acid and 12-oxophytodienoic acid showed the most remarkable rise. 11-OH-jasmonic acid was found at 14 d of culture in control and salt-treated hairy roots; whereas the 12-OH- form of jasmonic acid was only detected in the salt-treated hairy roots. Agrobacterium rhizogenes cultures did not produce jasmonates and/or octadecanoids.
Publikation
Among the multiple environmental signals and hormonal factors regulatingpotato plant morphogenesis and controlling tuber induction, jasmonates (JAs)andgibberellins (GAs) are important components of the signalling pathways in theseprocesses. In the present study, with Solanum tuberosum L.cv. Spunta, we followed the endogenous changes of JAs and GAs during thedevelopmental stages of soil-grown potato plants. Foliage at initial growthshowed the highest jasmonic acid (JA) concentration, while in roots the highestcontent was observed in the stage of tuber set. In stolons at the developmentalstage of tuber set an important increase of JA was found; however, in tubersthere was no change in this compound during tuber set and subsequent growth.Methyl jasmonate (Me-JA) in foliage did not show the same pattern as JA; Me-JAdecreased during the developmental stages in which it was monitored, meanwhileJA increased during those stages. The highest total amount of JAs expressed asJA + Me-JA was found at tuber set. A very important peak ofJA in roots was coincident with that observed in stolons at tuber set. Also, aprogressive increase of this compound in roots was shown during the transitionof stolons to tubers. Of the two GAs monitored, gibberellic acid(GA3) was the most abundant in all the organs. While GA1and GA3 were also found in stolons at the time of tuber set, noothermeasurements of GAs were obtained for stolons at previous stages of plantdevelopment. Our results indicate that high levels of JA and GAs are found indifferent tissues, especially during stolon growth and tuber set.
Publikation
In barley leaves a group of genes is expressed in response to treatment with jasmonates and abscisic acid (ABA) [21]. One of these genes coding for a jasmonate-induced protein of 23 kDa (JIP-23) was analyzed to find out the link between ABA and jasmonates by recording its expression upon modulating independently, the endogenous level of both of them. By use of inhibitors of JA synthesis and ABA degradation, and the ABA-deficient mutant Az34, as well as of cultivar-specific differences, it was shown that endogenous jasmonate increases are necessary and sufficient for expression of this gene. The endogenous rise of ABA did not induce synthesis of JIP-23, whereas exogenous ABA did not act via jasmonates. Different signalling pathways are suggested and discussed.