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Eukaryotic cell survives in predominantly reduced conditions. Homeostasis of cellular redox system is an imperative of cell surviving and its normal metabolism. ROS are well recognized for playing a dual role as both deleterious and beneficial species, since they can be either harmful or beneficial to living systems. These species are mutagenic compounds known to lead to DNA damage, favor cell transformation, and contribute to the development of a variety of malignant diseases. All the effects of oxidants are influenced by the cellular antioxidant defenses. This multilayer system consists of low molecular weight components and several antioxidant enzymes. Superoxide dismutases (SODs) are the only enzymes dismuting superoxide radicals. Mitomycin C, a cross-linking agent, demonstrated genotoxicity in all in vitro and in vivo test systems in mammalian cells and animals. Water-soluble fullerenes are well known as cytotoxic agents for many cell lines in vitro. At the other side, fullerenols are good free radical scavengers and antioxidants both in vitro and in vivo. This paper investigates the effects of fullerenol on survival and fullerenol/ /mytomicine (MMC) treatment on superoxide-dismutase (SOD) activity in CHO-K1 cells. Samples were treated 3 and 24 h with fullerenol (C60(OH)24) at concentration range 0.01-0.5 mg/mL and survival was monitored with dye exclusion test (DET). The activity of total SOD was estimated in samples treated with chosen concentrations of fullerenol and MMC (0.5 and 0.1 mg/mL) after 3 and 24 h of cell incubation. Increasing of C60(OH)24 concentration leads to decreasing of percent of surviving cells 3 and 24 h after incubation. The activity of total SOD enhanced with higher concentration of fullerenol, while decreased in the highest concentration at both experimental points. In samples treated with MMC, as well as in samples treated with fullerenol (0.0625 mg/mL) + MMC was noticed boost in total SOD activity in comparison with controls. Treatment with fullerenol decreased SOD activity in rest of samples treated with MMC. Decreased activity of superoxide-dismutase in almost all samples treated with fullerenol and MMC might be contributed to antioxidative properties of fullerenol. Increased enzyme level at concentration of 0.0625 mg/mL may be due to its prooxidative activity. U ovom radu ispitivani su efekti fulerenola (C60(OH)24) na preživljavanje, kao i tretmana fulerenolom i mitomicinom c (MMC) na aktivnost ukupne superoksid-dismutaze u CHO-K1 (ovarijalnih ćelija hrčka) ćelijskoj liniji. U uzorcima ćelija tretiranim fulerenolom koncentracija 0,01-0,5 mg/mL, praćeno je preživljavanje testom odbacivanja boje (DET) u 3 i 24 h tretmanu. Aktivnost superoksid-dismutaze (SOD) merena je u uzorcima tretiranim fulerenolom izabranih koncentracija i mitomicinom c (0,5 i 0,1 mg/mL) nakon 3 i 24 h. Sa porastom koncentracije (C60(OH)24) opada procenat preživelih ćelija tokom 3 i 24 h. Aktivnost SOD raste sa porastom koncentracije fulerenola i u najvećoj koncentraciji opada u obe vremenske tačke eksperimenta. U uzorcima tretiranim fulerenolom i MMC došlo je do smanjenja aktivnosti SOD, izuzev pri koncentraciji fulerenola od 0,0625 mg/mL, kada je zapažen porast aktivnosti SOD u odnosu na kontrolne grupe. Projekat ministarstva br. 142076

This paper investigates the effects of sodium nitroprusside as NO donor on two cell lines in culture: transformed cells of mice fibroblasts (L929) and malignant cells of human eritroleukemia (K562). Low concentrations of NO have stimulative effect, while high concentrations have inhibitive effects on proliferation of K562 cells in a dose-dependent manner. In our experiments, by using sodium nitroprusside (SNP) as NO donor and two kinds of superoxide dismutase, Cu,Zn-SOD and Mn-SOD, we created conditions to generate several kinds of signal molecules and investigated reaction of transformed (L929) and malignant (K562) cells to dose. Results of experiments are showing that chosen parameters (amount of free thiol groups and glutathione) may be relevant in monitoring the effect of exogenous nitrate oxide and its redox descendants in different, both transformed and malignant cell lines. U ovom radu ispitivani su efekti donora NO natrijum-nitroprusida (SNP) na dve ćelijske linije u kulturi: transformisane ćelije mišijih fibroblasta (L929) i maligne ćelije humane eritroleukemije (K562). Niske koncentracije deluju stimulativno na proliferaciju K562 ćelija u kulturi, dok je kod viših koncentracija situacija suprotna i uočava se dozno-zavisan uticaj SNP na proliferaciju K562 ćelija. Korišćenjem natrijum-nitroprusida i dve vrste superoksid dismutaza, Cu,Zn-SOD i Mn-SOD, stvoreni su uslovi generisanja više vrsta signalnih molekula i ispitan je odgovor obe ćelijske linije na njih. Rezultati eksperimenata pokazuju da izabrani parametri (količina slobodnih tiolnih grupa i glutationa) mogu biti relevantni za praćenje efekata egzogenog azot oksida i njegovih redoks potomaka kod različitih, transformisanih i malignih ćelijskih linija. null

Cell culture K562 samples were treated with fullerenol (C6o(OH)24) at a concentration of 10 nmol/mL and thereafter irradiated with X-rays (24Gy). The activity of gamma-glutamyltransfrease (γ-GT), total superoxide-dismutase (SOD) and glutathion-peroxidase (GSH-Px) was determined 1, 24 and 48 hours after irradiation. Irradiation induces an increase in the activity of all the investigated enzymes. Fullerenol in the applied dose decreased the γ-GT activity 24 and 48 h after irradiation. The total SOD activity is increased in both pretreated groups except in the irradiated group at the 48th hour. Treatment with fullerenol before irradiation increased GSH-Px activity in irradiated groups and decreased it in the control groups. U uzorcima ćelijske kulture humane eritroleukemije (K562) ozračenim X-zracima doze 24 Gy i predtretiranim fulerenolom (C60(OH)24) koncentracije 10 nmol/mL određivana je aktivnost gama-glutamiltransferaze (γ-GT), ukupne superoksid-dismutaze (SOD) i glutation-peroksidaze (GSH-Px) 1, 24 i 48 sati nakon zračenja. Iradijacija povećava aktivnost sva tri ispitivana enzima. U 24-om i 48-om satu nakon zračenja zapaža se sniženje aktivnosti γ-GT u grupama predtretiranim fulerenolom. Fulerenol utiče na povišenje aktivnosti SOD u obe tretirane grupe, osim u grupi ozračenih uzoraka u 48-om satu gde je došlo do sniženja aktivnosti. Predtretman fulerenolom u zračenim grupama povećava, a u neozračenim eksperimentalnim grupama snižava aktivnost GSH-Px. null