Aleksandar Djordjevic

Protective effects of fullerenol C60(OH)24 against doxorubicin-induced cardiotoxicity and hepatotoxicity in rats with colorectal cancer

The effects of fullerenol C60(OH)24 (Frl) at doses of 25, 50, and 100mg/kg/week (for a time-span of 3 weeks) on heart and liver tissue after doxorubicin (Dox)-induced toxicity in rats with colorectal cancer were investigated. In the present study, we used an in vivo Wistar male rat model to explore whether Frl could protect against Dox-induced (1.5mg/kg/week for 3 weeks) chronic cardio- and hepato- toxicity and compared the effect with a well-known antioxidant, vitamin C (100mg/kg/week for 3 weeks). According to macroscopic, microscopic, hematological, biochemical, physiological, pharmacological, and pharmacokinetic results, we confirmed that, at all examined doses, Frl exhibits a protective influence on the heart and liver tissue against chronic toxicity induced by Dox.

Potential hepatoprotective effects of fullerenol C60(OH)24 in doxorubicin-induced hepatotoxicity in rats with mammary carcinomas

The aim of this study was to investigate the potential protective role of fullerenol C60(OH)24 on doxorubicin-induced liver toxicity using in vivo (female Sprague-Dawley rats) and in vitro (human hepatocellular carcinoma - HepG2; colorectal adenocarcinoma cell lines - Caco-2) approaches. The first (healthy control) and second (control with chemically induced mammary carcinomas) group received saline only. The third, fourth and fifth group (all with breast cancer) were injected (i.p.) with a single dose of doxorubicin (8mg/kg), doxorubicin/fullerenol (100mg/kg of fullerenol 30min before administration of 8mg/kg doxorubicin) and fullerenol (100mg/kg), respectively. Two days after treatment, the rats were sacrificed. Results showed that treatment with doxorubicin alone caused significant changes in the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and alpha-hydroxybutyrate dehydrogenase (alpha-HBDH), as well as in the levels of malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GSH-Px), total antioxidant status (TAS), glutathione reductase (GR), catalase (CAT) and superoxide dismutase (SOD) in the liver tissue. These effects were significantly reduced for all investigated parameters by pre-treatment with fullerenol but not for the MDA and GSH level. The HepG2 and Caco-2 cell lines were continuously treated with fullerenol for 12h, 24h, 48h and 96h at concentrations of 10microg/mL and 44microg/mL. With the aim of evaluating the modulating activity of fullerenol on doxorubicin-induced hepatotoxicity, the cell lines were simultaneously treated with doxorubicin (1microm; 5microm) and fullerenol (10microg/mL; 44microg/mL) in different combinations. When the cells are treated with 5microm doxorubicin along with the fullerenol, we can see a significant improvement of the cell capability during the entire time-line. We can conclude that fullerenol has cytotoxic effects on HepG2 by itself, but when the oxidative stress is too high the cytotoxic effects of fullerenol are overcome by its protective role as a strong antioxidant compound.

Antioxidant properties of fullerenol C60(OH)24 in rat kidneys, testes, and lungs treated with doxorubicin

Clinical use of doxorubicin continues to be challenged by its undesirable systematic toxicity, caused mainly by oxidative stress. The aim of this study was to investigate the effectiveness of fullerenol C60(OH)24 polyanion nanoparticles, an antioxidant agent, against doxorubicin-induced nephro-, testicular, and pulmonary toxicity. Results obtained in vitro suggest that fullerenol’s anti-proliferative property and protective effect against doxorubicin cytotoxicity are mediated by the antioxidative and radical scavenging activity. Male Wistar rats were divided into five treatment groups: the control group (I) received 0.9% NaCl (1 mL/kg, i.p.). Groups II, III, IV, and V received a single dose of doxorubicin (10 mg/kg i.p.), doxorubicin/fullerenol (100 and 50 mg/kg i.p. of fullerenol 30 min prior to 10 mg/kg i.p. of doxorubicin), and fullerenol (100 mg/kg i.p.), respectively. On the 2nd and 14th days, organ samples were taken for the measurement of lipid peroxidation and activities of superoxide dismutase, catalase, glutathione-peroxidase, -reductase, and -transferase. Doxorubicin induced a significant increase of lipid peroxidation and alterations of antioxidant enzyme activities, while the fullerenol pre-treatment prevented the effects of doxorubicin on investigated parameters. Fullerenol, applied alone, did not alter basal values of the investigated animals. Considering the mechanisms of doxorubicin toxicity, it can be concluded that fullerenol exerts its protective role by acting as a free radical sponge and/or by removing free iron through formation of fullerenol-iron complex. Results of this study support the hypothesis of testicular, pulmo-, and nephroprotective efficacy of fullerenol in preventing oxidative stress induced by doxorubicin.

Catalytic Preparation and Characterization of C60Br24

Abstract In this paper the procedure for catalytical bromination of C60 with elementary bromine with FeBr3 as a catalyst is described. In this procedures only one reaction product - C60 Br24 is obtained. The twenty four bromine atoms are symmetrically distributed over the C60 sphere, which was confirmed by thermogravimetric analysis. The yield of bromine derivative in this reaction is 98%.

Effects of fullerenol C60(OH)24 on the frequency of micronuclei and chromosome aberrations in CHO-K1 cells

Poly-hydroxylated C(60) fullerenols (C(60)(OH)(n)) have attracted much attention in biomedical research, due to a variety of biological activities. However, the studies investigating the genotoxic effects of fullerenols are still insufficient. The aim of the present study was to analyze the genotoxic and antigenotoxic potential of fullerenol C(60)(OH)(24). The investigation was carried out with mitomycin C (MMC)-treated and control Chinese hamster ovary cells (CHO-K1), using the chromosome aberration (CA) assay and the cytokinesis-block micronucleus (CBMN) test. Cells were treated with fullerenol nanoparticles, which are well known for their antioxidative properties and cytoprotective effects, both in vivo and in vitro. Our study showed the absence of genotoxicity of fullerenol in a wide range of concentrations (11-221 microM). Fullerenol mediated the decrease in the frequency of micronuclei (MN) and chromosome aberrations compared with the controls at all endpoints examined. A dose-dependent decrease of MN frequency was found 24h after treatment with fullerenol, in contrast to the outcome of the CA assay. Cell proliferation was equally influenced by fullerenol. The majority of aberrations were of the chromosome-type. Our results show that fullerenol does not induce genotoxic effects, and that it protects both non-damaged and MMC-damaged CHO-K1 cells.

Acute doxorubicin pulmotoxicity in rats with malignant neoplasm is effectively treated with fullerenol C60(OH)24 through inhibition of oxidative stress

The aim of this study was to investigate the possible protective role of fullerenol (FLR, C(60)(OH)(24) on doxorubicin (DOX)-induced lung toxicity using biochemical and histopathological approaches. Rats (Sprague-Dawley outbred) were randomly divided into five groups. The healthy control group received no medication (saline only). The other four groups had chemically induced breast cancer (1-methyl-1-nitrosourea; 50 mg/kg, ip). The second group was the cancer control group (saline only). The other three groups were DOX (8 mg/kg, ip), FLR/DOX (100 mg/kg, ip, 30 min before DOX; 8 mg/kg, ip), and FLR (100 mg/kg, ip), respectively. The levels of malondialdehyde (MDA) and oxidized glutathione (GSSG) in the lung tissue were higher in the group treated with DOX alone than in the control groups. The activities of catalase (CAT), glutathione reductase (GR), superoxide dismutase (SOD), and lactate dehydrogenase (LDH) were found to be increased in the lung tissue of the animals in the DOX group over all the other groups, while GSH-Px significantly decreased in activity compared with the control and FLR groups. There was no significant difference in MDA and GSSG levels and enzyme activities in either control (healthy; cancer) or FLR (FLR/DOX; FLR) groups. The acute change found in the DOX group was subpleural edema. In contrast, the groups treated with FLR appeared to be virtually histopathologically normal. In conclusion, this study clearly indicates that DOX treatment markedly impairs pulmonary function and that pre-treatment with FLR might prevent this toxicity in rats through inhibition of oxidative stress.

Cardioprotective Effects of Fullerenol C60(Oh)24 on a Single Dose Doxorubicin-induced Cardiotoxicity in Rats with Malignant Neoplasm

The therapeutic utility of the anthracycline antibiotic doxorubicin is limited due to its cardiotoxicity. Our aim was to investigate the efficacy of fullerenol C60(OH)24 in preventing single, high-dose doxorubicin-induced cardiotoxicity in rats with malignant neoplasm. Experiment was performed on adult female Sprague Dawley rats with chemically induced mammary carcinomas. The animals were sacrificed two days after the application of doxorubicin and/or fullerenol, and the serum activities of CK, LDH and α-HBDH, as well as the levels of MDA, GSH, GSSG, GSH-Px, SOD, CAT, GR, and TAS in the heart, were determined. The results obtained from the enzymatic activity in the serum show that the administration of a single dose of 8 mg/kg in all treated groups induces statistically significant damage. There are significant changes in the enzymes of LDH and CK (p < 0.05), after an i.p. administration of doxorubicin/fullerenol and fullerenol. Comparing all groups with untreated control group, point to the conclusion that in the case of a lower α-HBDH/LDH ratio, results in more serious the liver parenchymal damage. The results revealed that doxorubicin induced oxidative damage and that the fullerenol antioxidative influence caused significant changes in MDA, GSH, GSSG, GSH-Px, SOD, CAT, GR, and TAS level in the heart (p < 0.05). Therefore, it is suggested that fullerenol might be a potential cardioprotector in doxorubicin-treated individuals.

Fullerenol C60(OH)24 prevents doxorubicin-induced acute cardiotoxicity in rats

Results obtained in vitro suggested that fullerenols antiproliferative properties and protective effects against doxorubicin (DOX) cytotoxicity are mediated by antioxidative and hydroxyl radical scavenger activity. The aim of this study was to examine the influence of fullerenol on acute cardiotoxicity after the administration of a single high dose of DOX in vivo. The experiment was performed on male Wistar rats randomly divided into five groups, each containing eight individuals, that were treated as follows: I) 0.9% NaCl, II) 10 mg/kg DOX, III) 50 mg/kg fullerenol 30 min before 10 mg/kg DOX, IV) 100 mg/kg fullerenol 30 min before 10 mg/kg DOX, and V) 100 mg/kg fullerenol. A functional, biochemical, hematological, and pathomorphological examination of the heart as well as an evaluation of oxidative stress parameters was conducted on days 2 and 14 after DOX administration. The function of the heart was investigated by monitoring heart contractility after the adrenaline infusion. Fullerenol, applied alone, did not alter basal values of investigated animals. Both doses of fullerenol, used as a pretreatment, did not alter the basal parameters of the animals. The 100 mg/kg dose of fullerenol showed better protection. Considering the mechanisms of DOX toxicity, fullerenol likely exerts its protective role as a free radical sponge and/or by removing free iron through the formation of a fullerenol-iron complex. Our results suggest that fullerenol might be a potential cardioprotective agent in DOX-treated individuals.

Activity of Antioxidative Enzymes in Erythrocytes after a Single Dose Administration of Doxorubicin in Rats Pretreated with Fullerenol C 60 (OH) 24

In earlier in vitro investigations, fullerenol was shown to have a strong antioxidative capability. The present study examined the role of fullerenol as a potential antioxidative protector for doxorubicin-induced oxidative stress in the blood of rats through an investigation of the activity of glutathione-dependent enzymes (glutathione-S-transferase and glutathione peroxidase). It also assessed the influence of fullerenol on the number of blood cells (leukocytes and erythrocytes) as well as on the content of hemoglobin after a single dose administration of doxorubicin. Experiments were performed on six groups of adult male Wistar rats, each group containing eight individuals. Doxorubicin was administrated i.v. (tail vein) in a single dose of 10 mg/kg. Fullerenol C60(OH)24 was administrated to the treated animals i.p. (in doses 50, 100, 200 mg/kg) 30 min before the dosing with doxorubicin. The control group animals were given saline (1 ml/kg; i.p.). One group of animals was treated only with fullerenol (100 mg/kg i.p.). The animals were sacrificed 2 and 14 days after the treatment. Each experiment was repeated twice. The results may indicate that fullerenol induces a decrease in the antioxidative capacity of erythrocytes in oxidative stress conditions, whereas, without doxorubicin, the application of fullerenol did not induce any changes in the enzyme activity of erythrocytes. The results of GST activity might indicate that 50 mg/kg are not sufficient to protect from doxorubicin toxicity, while 200 mg/kg might be toxic for animals, judging from the increase in GST activity.

Radioprotective Efficiency of Fullerenol in Irradiated Mice

In vitro studies have demonstrated that fullerenol, a polyhydroxylated derivative of fullerene (C60(OH)n n = 12-26), has a high antioxidative potential. Since any radiation injury is mainly a consequence of the action of free radical species, the aim of this study was to examine radioprotective efficiency of fullerenol in whole-body irradiated mice. The experiment was performed on male, adult, white mice, whole-body irradiated with Xrays doses of 6 to 8 Gy (X-ray energy of 8 MV). Fullerenol C60(OH)24 was given in doses of 10 and 100 mg/kg i.p. 30 minutes before irradiation. The experimental groups consisted of 25-30 animals each. The survival rate and body mass gain of irradiated animals were monitored for 30 days after irradiation. The mean lethal times (LT50) of irradiated mice and mean lethal dose of X-rays were calculated and compared. The results showed that fullerenol C60(OH)24, in a dose of 100 mg/kg i.p., prolonged LT50 of irradiated mice. This effect was especially pronounced in mice irradiated with 7 and 8 Gy of X-rays. It seems that radioprotective efficiency of fullerenol C60(OH)24 is more marked in mice irradiated by higher doses of X-rays.