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The therapeutic action of nitroaromatic antiandrogens nilutamide and flutamide may be complicated by their cytotoxicity, whose mechanisms are still incomprehensively understood. In particular this concerns the enzymatic redox cycling of flutamide and its metabolites, and its impact on their cytotoxicity. In this work, we examined the single-electron reduction of nilutamide, flutamide, its metabolites 2-hydroxyflutamide and 4-nitro-3-trifluorormethyl-phenylamine, and a topical antiandrogen (3-amino-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl)-phenyl) propanamide by NADPH:cytochrome P-450 reductase and adrenodoxin reductase/adrenodoxin. The obtained steady-state bimolecular rate constants of oxidant reduction (kcat/Km) enabled to establish single-electron reduction midpoint potentials (E17) of compounds, −0.377 – −0.413 V, which were in line with enthalpies of formation of their free radicals, obtained by quantum mechanical calculations. Using murine hepatoma MH22a cells, the obtained cytotoxicity vs. E17 correlation based on the data of model nitroaromatic compounds shows that redox cycling and oxidative stress could be the main factor of cytotoxicity of nitroaromatic antiandrogens. Other minor cytotoxicity factors could be their redox metabolism involving NAD(P)H:quinone oxidoreductase (NQO1) and cytochromes P-450.

Nitroaromatic explosives and their degradation products are toxic enviromnental pollutants. In this paper, we summarize the available data on the chemical aspects of toxicity of the classical and the new generation nitroaromatic explosives, i.e. their flavoenzyme-catalyzed single- and two-electron reduction and the impact of these reactions on fhe mammalian cell cytotoxicity of explosives. The leading role of the oxidative stress-type cytotoxicity of nitroaromatic explosives has been demonstrated m bovine leukemia virus-transformed lamb kidney fibroblasts (line FLK) and, possibly, in mouse splenocytes., Nitroaromatiniai sprogmenys ir jų degradacijos produktai yra toksiški aplinkos teršalai. Šiame straipsnyje apibendrinamį duomenys apie klasikinių ir naujos kartos nitroaromatinių sprogmenų toksiškumo cheminius aspektus, t. y. apie jų vien- ir dvielektroninį redukciją, katalizuojamą flavinimais fermentais, ir šių reakcijų reikšmę sprogmenų citotoksiškumui žinduolių ląstelėse. Šiuo metu nustatyta, kad pagrindinis nitroaromatinių junginių citotoksiškumo mechanizmas galvijų leukemijos virusu transformuotuose ėriuko inkstų fibroblastuose (linija FLK-) ir, greičiausiai, pelės blužnies ląstelėse yra oksidacinis stresas.

Effect of Experimental ImunoM–I Product from Saccharomyces cerevisiae β-glucans on Malignant Cells In the thesis the effect of various concentrations of experimental ImunoM-I product from Saccharomyces cerevisiae soluble β-glucans on several cell lines: murine macrophage–like RAW 246.7, human hepatoblastoma HepG2 and murine hepatoma MH22a was tested. Different cell culture concentrations and DME medium with different glucose and pyruvate concentrations were used in the experiments. Phagocytosis activity and proliferation were estimated by employing fluorescent microscopy and acridine orange (AO) and ethidium bromide (EB) dyes. Cells proliferation was also estimated by using spectrophotometry and AlamarBlue dye. It has been revealed that phagocytosis activity and proliferation increase when RAW246.7 cell line is cultured with lower ImunoM-I concentrations for 96 hours. On the contrary when malignant cells are treated with ImunoM-I, the results indicate that lower concentrations inhibite HepG2 and MH22a proliferation. The results show that pyruvate increases the effect of the experimental ImunoM-I product. The results have been found to be statistically reliable if P < 0,05 and n ≥ 3. The work consists of seven parts: introduction, literature, methods, results, discusion, conclusions and references. The Bachelor thesis consists of: 54p. text, 20 pictures, 1 table, 52 bibliographical entries.

Ląstelės metabolizme svarbų vaidmenį vaidina oksidacijos – redukcijos reakcijos, kuriose deguonis yra elektronų akceptorius. Įvairių cheminių reakcijų metu gali susidaryti ir aktyviosios deguonies formos – superoksido anijonas, vandenilio peroksidas, hidroksilo radikalas, singletinis deguonis, kurios pažeidžia įvairias biomolekules. Augalai nuo seniausių laikų yra vartojami įvairioms ligoms gydyti. Flavonoidai – tai augalinės kilmės junginiai, randami vaisiuose, daržovėse arbatose, kurie pasižymi antioksidacinėmis savybėmis. Sintetiniai antioksidantai polifenoliai labai plačiai naudojami maisto pramonėje, kaip įvairūs priedai ir konservantai. Vienas jų - kvercetinas. Kvercetino antioksidacinis poveikis priklauso nuo to, kad jis reaguoja su laisvaisiais radikalais, sudarydamas fenoksradikalus, kurie yra ne tokie aktyvūs. Tačiau aukštos kvercetino koncentracijos yra citotoksiškos, o citotoksiškumo mechanizmai, nors ir labai plačiai tyrinėjami visame pasaulyje, lieka neaiškūs. Mūsų darbo tikslas ir buvo ištirti kvercetino ir kitų flavonoidų poveikį Hep 22a linijos ląstelėms. Hep 22a ląstelių linija pasirinkta neatsitiktinai. Tai pelių hepatomos ląstelių kultūra, kuri pasižymi navikinėms ląstelėms būdingomis savybėmis – neribota proliferacija ir ląstelių migracija. Vyrauja epitelinio tipo ląstelės, kurias persėjus po oda susidaro navikai. Ląstelės gerai auga tiek in vivo, tiek in vitro. Ląstelės pailgos, prisitvirtinusios prie substrato, sudaro monosluoksnį. Tirtų flavonoidų... [toliau žr. visą tekstą] ABSTRACT Flavonoids are widely distributed in edible plants, and considered to be dietary antioxidants. Flavonoids can protect cell from „oxidative stress“, but the same flavonoids compound could behave in two ways as an both antioxidant and prooxidant, depending on the concentration used and free radical source. Among the flavonoids, quercetin is one of the most widely studied flavonoid and has biological, pharmocological, and medicinal properties. Besides the chemopreventive effects, other biological functions of quercetin are believed to improve antioxidant defence systems in living organizms. The aim of this work was to analize the effects of flavonoids (quercetin, myricetin and morin) in Hep 22a cells. Materials and methods: 1. Cell culture cytotoxicity studies; Flavonoids and the other components were obtained from Sigma, and used as received. 2. Study with fluorescence microscope 3. Statistical analysis Results and discusion: Hep 22a cell line is a mouse hepatoma cell line, which posseses the unlimited proliferation and migration features. Quercetin concentration for 50 % death of Hep 22a cells (cL50) was 160 µM, myricetin concentration was 60 µM, and morin concentration was 190 µM,. The citotoxity of flavonoids in Hep 22a cells was partly inhibited by catalase, by the antioxidant N,N‘-diphenyl-p-phenylene diamine DPPD, desferrioxamine and by dicumarol and an inhibitor of DT-diaphorase thus showing its prooxidant character. Inhibitors of cytochromes P-450, &#945... [to full text]

Human mesenchymal stem cells (MSC) have attracted a great deal of interest for their potential use in regenerative medicine and suppression of the inflammation. Nevertheless, all known therapy protocols require large amounts of MSCs, which can be obtained only by in vitro expansion. One of the most important methodological problems is associated with the use of animal-derived components in the cell culture medium. The main aim of the current research was to elucidate the influence of different serum substitutes on the proliferation, differentiation, expression of cell surface markers, and total protein expression of mesenchymal stem cells derived from human adipose tissue. In addition we were aiming to determine the features of mesenchymal stem cell populations from an exfoliated deciduous tooth (SHED) and their response to the multifunctional proinflammatory protein alpha1-antitrypsin. Our results indicate that adipose tissue derived MSCs cultivated in the presence of fetal calf serum and allogeneic human serum display similar properties, while synthetic serum substitute induces increase in growth and differentiation potential of MSCs. Moreover, our results indicate, that synthetic serum substitute also activates transcription of genes related to adipogenic and osteogenic differentiation and diminishes expression of cell surface marker CD146. In the present study, we used a proteomic approach that allowed us to compare protein expression signatures between primary cell... [to full text] Žmogaus suaugusio organizmo mezenchiminės kamieninės ląstelės (MKL) pradėtos sėkmingai naudoti pažeistų audinių regeneracijai ir uždegiminio proceso slopinimui. Šiuolaikiniams terapijos protokolams yra reikalingi dideli ląstelių kiekiai, todėl prieš naudojimą yra būtina jas padauginti in vitro. Tačiau naudojant skirtingus MKL išskyrimo, in vitro kultivavimo ir padauginimo protokolus, yra sunku lyginti mokslinių tyrimų duomenis ir klinikinių tyrimų rezultatus. Nevienodos kultivavimo sąlygos gali įtakoti MKL funkcines savybes (augimo greitį, gebėjimą diferencijuotis, migracinį aktyvumą ir kt.). Šiame disertaciniame darbe tyrėme auginimo terpių, praturtintų skirtingais serumais (gyvulinės kilmės serumai, žmogaus alogeninis serumas, sintetinis serumas), poveikį žmogaus riebalinio audinio MKL. Taip pat charakterizavome MKL išskirtas iš žmogaus pieninių dantų pulpos ir palyginome šių ląstelių kultūros bei jų dukterinių klonų savybės. Kompleksiškai tyrėme uždegimo antiproteinazės alfa1-antitripsino (AAT) poveikį šioms ląstelėms. Nustatėme, kad, lyginant su kitais tyrime naudotais serumais, sintetinis serumo pakaitalas geriausiai skatino MKL augimą bei gebėjimą diferencijuotis adipogenine ir osteogenine kryptimis. Taip pat, skirtingai nuo kitų naudotų gyvulinės kilmės ir žmogaus serumų, sintetinis serumo pakaitalas veikė kaip adipogeninės ir osteogeninės diferenciacijos indukcijai svarbių genų PPARγ ir Msx2 transkripcijos aktyvatorius. Be to, sintetinis serumo pakaitalas slopino... [toliau žr. visą tekstą]

Šiuolaikinėje chemoterapijoje plačiai naudojami įvairūs chinonai. Pastaraisiais metais atkreiptas dėmesys į tai, kad chinonai, turintys aziridino grupes savo struktūroje yra labai toksiški piktybinėms ląstelėms. Šių junginių citotoksiškumo mechanizmai nėra pakankamai išanalizuoti. Šio darbo tikslas buvo ištirti skirtingų chinonų, tarp jų ir aziridino grupes turinčių, poveikį GLV – transformuotoms FLK ląstelėms. Tai yra avies embriono inkstų ląstelės, fibroblastų kilmės, transformuotos galvijų leukemijos virusu. Jos pasižymi vėžinėms ląstelėms būdingomis savybėmis: neribota proliferacija ir padidėjusiu prooksidantinių fermentų aktyvumu, kuris sąlygoja didesnį jautrumą chinonams, sukeliantiems oksidacinį stresą ir skatinantiems ląstelės žūtį. Gauti rezultatai parodė, kad chinonai, turintys savo struktūroje aziridino grupes (RH1 ir MeDZQ) yra toksiškesni FLK ląstelėms, negu chinonai, neturintys aziridino grupių (daunorubicinas ir durochinonas). Visų šių chinonų citotoksinį poveikį lemia kombinuotas mechanizmas: oksidacinis stresas, DT-diaforazės ir ksantinoksidazės veikla. Manoma, kad kai kurie aziridinilo grupes turintys chinonai gali būti labai perspektyviais priešvėžiniais vaistais. Many of recently used chemotherapeutic agents have a quinoidal structure. It is supposed that the main mechanism of antitumour aziridinyl substituted benzoquinones is their two-electron reduction to alkylating products. However, other possible cytotoxicity mechanisms, e.g., oxidative stress, are studied insufficiently. The goal of our investigation was to analyse quinones influence to apoptosis in FLK (foetal lamb kidney fibroblasts) line, which posses increased prooxidant activities. The results show that quinones, which have aziridinyl substituents (RH1 and MeDZQ) are more cytotoxic than quinones without these substituents (daunorubicin and duroquinone). Cytotoxic effect of those quinones to cells is conditioned by combinative mechanism of oxidative stress, DT-diaforase and xantinoxidase action. It is supposed that aziridinyl substituted benzoquinones may be very perspective in antitumour treatment.

Flavonoids are widely distributed in edible plants, and considered to be dietary antioxidants. Flavonoids can protect cell from „oxidative stress“, but the same flavonoids compound could behave in two ways as an both antioxidant and prooxidant, depending on the concentration used and free radical source. Among the flavonoids, quercetin is one of the most widely studied flavonoid and has biological, pharmocological, and medicinal properties. Besides the chemopreventive effects, other biological functions of quercetin are believed to improve antioxidant defence systems in living organizms. The aim of this work was to analize the effects of flavonoids (quercetin, myricetin and morin) in Hep 22a cells. Materials and methods: 1. Cell culture cytotoxicity studies; Flavonoids and the other components were obtained from Sigma, and used as received. 2. Study with fluorescence microscope 3. Statistical analysis Results and discusion: Hep 22a cell line is a mouse hepatoma cell line, which posseses the unlimited proliferation and migration features. Quercetin concentration for 50 % death of Hep 22a cells (cL50) was 160 µM, myricetin concentration was 60 µM, and morin concentration was 190 µM,. The citotoxity of flavonoids in Hep 22a cells was partly inhibited by catalase, by the antioxidant N,N‘-diphenyl-p-phenylene diamine DPPD, desferrioxamine and by dicumarol and an inhibitor of DT-diaphorase thus showing its prooxidant character. Inhibitors of cytochromes P-450, α-naphthoflavone and izoniazide, decreased the cytotoxicity of flavonoids, whereas 3,5-dinitrocatechol, an inhibitor of catechol-o-methyltransferase (COMT), increased it. Next, we examined the effects of the antioxidant on cytotoxicity and apoptosis induction. Quercetis is a dietary anticancer chemical that is capable of inducing apoptosis in tumor cells. We also investigated the effects of quercetin and myricetin on apoptosis of Hep 22a cells. Quercetin and myricetin induced apoptosis in 30 % of cells. The antioxidant N,N‘-diphenyl-p-phenylene diamine DPPD, desferrioxamine and the inhibitor of NQ01 dicumarol, protect against apoptosis with all compounds investigated, but only to a different extent. This shows that for all compounds investigated, there exists a common apoptosis and cytotoxity mechanism, namely an oxidative stress.