The aim of the study is to investigate the differences in the interaction of three structurally diverse anthocyanidins, namely peonidin, petunidin, and delphinidin, as well as their glucosides with model biological membranes, human albumin, and plasmid DNA in order to look into their structure-activity relationships. Fluorimetric studies, as well as ATR-FTIR analyses, were jointly used in order to determine the changes observed in both the hydrophilic and hydrophobic layers of cell-mimic membranes (MM) which reflected the membrane lipid composition of tumour cells and red blood cell membranes (RBCM). Our results showed that anthocyanins and anthocyanidins can cause an increase in the packing order of the polar heads of lipids, as well as interact with their deeper layers by reducing the fluidity of lipid chains. The results presented here indicate that all compounds tested here possessed the ability to bind to human serum albumin (HSA) and the presence of a glucose molecule within the structures formed by anthocyanidin reduces their ability to bind to proteins. Using fluorescence correlation spectroscopy, it was demonstrated that the compounds tested here were capable of forming stable complexes with plasmid DNA and, particularly, strong DNA conformational changes were observed in the presence of petunidin and corresponding glucoside, as well as delphinidin. The results we obtained can be useful in comprehending the anthocyanins therapeutic action as molecular antioxidants and provide a valuable insight into their mechanism of action.
The aim of the study was to broadly determine the biological activities of purple potato ethanolic extract of the Blue Congo variety (BCE). The antioxidant activity of BCE was determined in relation to liposome membranes, and peroxidation was induced by UVB and AAPH. To clarify the antioxidant activity of BCE, we investigated its interactions with hydrophilic and hydrophobic regions of a membrane using fluorimetric and FTIR methods. Next, we investigated the cytotoxicity and pro-apoptotic activities of BCE in two human colon cancer cell lines (HT-29 and Caco-2) and in normal cells (IPEC-J2). In addition, the ability to inhibit enzymes that are involved in pro-inflammatory reactions was examined. Furthermore, BCE interactions with serum albumin and plasmid DNA were investigated using steady state fluorescence spectroscopy and a single molecule fluorescence technique (TCSPC-FCS). We proved that BCE effectively protects lipid membranes against the process of peroxidation and successfully inhibits the cyclooxygenase and lipoxygenase enzymes. Furthermore, it interacts with the hydrophilic and hydrophobic parts of lipid membranes as well as with albumin and plasmid DNA. It was observed that BCE is more cytotoxic against colon cancer cell lines than normal IPEC-J2 cells; it also induces apoptosis in cancer cell lines, but does not induce cell death in normal cells.
- MeSH
- albuminy MeSH
- antioxidancia chemie farmakologie MeSH
- antitumorózní látky fytogenní chemie farmakologie MeSH
- inhibitory cyklooxygenasy chemie farmakologie MeSH
- inhibitory lipoxygenas chemie farmakologie MeSH
- lidé MeSH
- lipidy chemie MeSH
- liposomy MeSH
- nádorové buněčné linie MeSH
- plazmidy MeSH
- reaktivní formy kyslíku MeSH
- rostlinné extrakty chemie farmakologie MeSH
- sérový albumin chemie metabolismus MeSH
- Solanum tuberosum chemie MeSH
- vazba proteinů MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Structural properties of plasmid DNA and model lipid membrane treated with newly synthesized platinum(II) complex cis-[PtCl2{P(CH2CH2COOH)3}2] (cis-DTCEP for short) were studied and compared with effects of anticancer drug cisplatin, cis-[Pt(NH3)2Cl2] (cis-DDP for short). Time Correlated Single Photon Counting Fluorescence Correlation Spectroscopy (TCSPC-FCS) was employed to study interactions between those platinum complexes and DNA. The TCSPC-FCS results suggest that bonding of cis-DTCEP derivative to DNA leads to plasmid strain realignment towards much more compact structure than in the case of cis-DDP. Application of both differential scanning calorimetry and infrared spectroscopy to platinum complexes/DPPC showed that cis-DTCEP slightly increases the phospholipid's main phase transition temperature resulting in decreased fluidity of the model membrane. The newly investigated compound-similarly to cis-DDP-interacts mainly with the DPPC head group however not only by the means of electrostatic forces: this compound probably enters into hydrophilic region of the lipid bilayer and forms hydrogen bonds with COO groups of glycerol and PO2- group of DPPC.
New butyltin complexes with 2-sulfobenzoic acid: [Sn(C4H9)2{O3SC6H4COO-2}(H2O)]·(C2H5OH) (DBTsbz), [Sn(C4H9)3{O3SC6H4COOH-2}] (TBTsbz) and [Sn2(C4H9)6{μ-O3SC6H4COO-2}] (DTBTsbz) are very effective cytotoxic agents against tumor cells. The molecular interaction of these complexes with lipid membranes and DNA has been investigated. The IR spectra and changes of (1)H, (13)C chemical shifts suggest that SO3 and COO groups of 2-sulfobenzoato ligand interact with O atom of glycerin fragment of DPPC. Moreover, the compounds form Sn-OP bonds with phosphate groups of DPPC, which was shown by the lower frequency shift of the νs(PO2(-)) and νas(PO2(-)) band, by change of (31)P NMR signals and by DFT calculation. Another possibility is the interaction of the phosphate group of DPPC owing to formation of hydrogen bond O-H…O-P between water molecule coordinated to Sn and oxygen atom from the phosphate group. Using TCSPC-FCS we characterized DNA supramolecular assemblies' formation upon increasing TBTsbz, DTBTsbz and DBTsbz concentration. Diffusion time, lifetime and particle number changes are altered systematically with increasing Ccomp/CDNAbp ratio in following effectiveness order DBTsbz > TBTsbz > DTBTsbz. From those parameters we can conclude that all these compounds lead to a change of DNA winding, strand but not to DNA compaction. Investigated compounds show very high cytotoxic activity against cancer cell lines. All compounds exhibit efficient in vitro antitumor activity toward Jurkat (T-cell leukemia), CL-1 (T-lymphoblastoid cell line), GL-1 (B cell lymphoma cell line) and D-17 (canine osteosarcoma). The DBTsbz is more effective then carboplatin against canine osteosarcoma.
- MeSH
- antitumorózní látky chemie farmakologie MeSH
- benzensulfonáty chemie farmakologie MeSH
- benzoáty chemie farmakologie MeSH
- DNA chemie metabolismus MeSH
- konformace nukleové kyseliny účinky léků MeSH
- krystalografie rentgenová MeSH
- léky antitumorózní - screeningové testy MeSH
- lidé MeSH
- lipidové dvojvrstvy chemie metabolismus MeSH
- molekulární modely MeSH
- nádorové buněčné linie MeSH
- nádory farmakoterapie MeSH
- organocínové sloučeniny chemie farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Lipopolythioureas (LPT) are original non cationic systems representing an alternative to cationic lipids. Their high transfection efficiency prompted us to investigate further their biophysical properties, and in particular how thiourea lipids interact with DNA. The interaction of lipopolythiourea with DNA was investigated by fluorescence correlation microscopy (FCS). Influence of the lipid length and nature of the thiourea head on the thiourea/DNA interaction were studied. FCS revealed a strong interaction between lipopolythiourea and DNA, occurring at 1 equivalent of a thiourea lipid by a DNA phosphate group, and leading to a condensed plasmid state. From previous in vitro experiments, we could conclude that the lipid leading to the more condensed state of DNA was also the more efficient to transfect cells.
The compaction of DNA plays a role in the nuclei of several types of cells and becomes important in the non-viral gene therapy. Thus, it is in the scope of research interest. It was shown, that spermine-induced compaction of large DNA molecules occurs in a discrete "all-or-non" regime, where the coexistence of free and folded DNA molecules was observed. In the case of intermediate-sized DNA molecules (approximately 10 kbp), so far, it was stated that the mechanism of folding is continuous. Here, we show, that neither a standard benchmark technique-dynamic light scattering, nor a single molecule technique such as fluorescence correlation spectroscopy, can decide what kind of mechanism is undertaken in the compaction process. Besides, we introduce an application of a new approach-fluorescence lifetime correlation spectroscopy. The method takes an advantage of a subtle lifetime change of an intercalating dye PicoGreen during the titration with spermine and based on that, it reveals the discrete mechanism of the process. Furthermore, we show that it allows for observation of the equilibrium state transition dynamics.
BACKGROUND: Fluorescence correlation spectroscopy (FCS) can be used for the determination of diffusion coefficients of single molecules. Since diffusion coefficients are correlated with size and shape of the labeled species, FCS provides information on conformational changes in plasmids aggregates. METHODS: A 10-kbp plasmid stained with PicoGreen was condensed by spermine or liposomes formulated from cationic lipid and egg phosphatidylcholine. RESULTS: The diffusion coefficient of DNA increases from 1.0 x 10(-12) m2/s to 3.2 x 10(-12) m2/s by the addition of spermine, whereas the addition of cationic liposomes leads to complexes characterized by diffusion coefficients with values ranging from 1.7 to 1.9 x 10(-12) m2/s. CONCLUSIONS: FCS experiments allow determining the diffusion coefficients of DNA-containing aggregates which provide information regarding the topology and homogeneity of the aggregate.
