Effects of high doses of vitamins C and E against doxorubicin-induced chromosomal damage in Wistar rat bone marrow cells

α-tocopherol as a selective modulator of toxicogenic damage induced by antineoplastic agents cyclophosphamide and doxorubicin

The aim of this study was to determine the oxidative/antioxidative effects, modulatory and selective potential of α-tocopherol (vitamin E) on antineoplastic drug-induced toxicogenetic damage. The toxicity, cytotoxicity and genotoxicity induced by antineoplastic agents cyclophosphamide (CPA) and doxorubicin (DOX) was examined utilizing as models Saccharomyces cerevisiae, Allium cepa, Artemia salina and human peripheral blood mononuclear cells (PBMCs) in the presence of α-tocopherol. For these tests, concentrations of α- tocopherol 100 IU/ml (67mg/ml), CPA 20 µg/ml, DOX 2 µg/ml were used. The selectivity of α-tocopherol was assessed by the MTT test using human mammary gland non-tumor (MCF10A) and tumor (MCF-7) cell lines. Data showed cytoplasmic and mitochondrial oxidative damage induced by CPA or DOX was significantly diminished by α-tocopherol in S. cerevisiae. In addition, the toxic effects on A. salina and cytotoxic and mutagenic effects on A. cepa were significantly reduced by α-tocopherol. In PBMCs, α-tocopherol alone did not markedly affect these cells, and when treated in conjunction with CPA or DOX, α-tocopherol reduced the toxicogenetic effects noted after antineoplastic drug administration as evidenced by decreased chromosomal alterations and lowered cell death rate. In human mammary gland non-tumor and tumor cell lines, α-tocopherol produced selective cytotoxicity with 2-fold higher effect in tumor cells. Evidence indicates that vitamin E (1) produced anti-cytotoxic and anti-mutagenic effects against CPA and DOX (2) increased higher selectivity toward tumor cells, and (3) presented chemoprotective activity in PBMCs.

Modulating effect of DL-kavain on the mutagenicity and carcinogenicity induced by doxorubicin in Drosophila melanogaster

Kavain, kavalactone, present in Piper methysticum exhibits anticonvulsive, analgesic, anxiolytic, antiepileptic, antithrombotic, anti-inflammatory and antioxidant properties. Given its importance, the aim of the present study was to assess (1) the mutagenic and carcinogenicity of kavain administered alone and (2) the antimutagenic and anticarcinogenic potential when administered simultaneously with the chemotherapeutic drug doxorubicin (DXR) using the Somatic Mutation and Recombination Test (SMART) and Epithelial Tumor Test (ETT) using Drosophila melanogaster as a model system. Third-stage larvae from a standard (ST) and high metabolic bioactivation (HB) crosses were treated with different kavain concentrations (32, 64 or 128 μg/ml), alone or in conjunction with DXR (0.125 mg/ml). In ST descendants, kavain produced no significant mutagenic or recombinogenic effects. In the HB cross, mutagenic activity was observed at kavain concentrations of 64 and 128 μg/ml. In the DXR and kavain co-treatment, a modulating effect of the DXR-mediated mutagenic response dependent upon the concentration was detected in both crosses. In ETT, no marked carcinogenic or anticarcinogenic activity was noted for kavain. However, when kavain was combined with DXR synergistic induction of tumors by the chemotherapeutic drug occurred indicating that kavain enhanced the carcinogenic action of DXR.

Structural, luminescence and geno/cytoxicity study of carbon dots derived from Opuntia ficus-indica (L.) Mill

Carbon dots derived from nopal significantly increase the number of micronuclei in mouse erythrocytes and inhibit mouse bone marrow cell proliferation.

Protective effects of bark ethanolic extract from Spondias dulcis Forst F. against DNA damage induced by benzo[a]pyrene and cyclophosphamide

This study evaluated the genotoxicity, mutagenicity, antigenotoxicity, and antimutagenicity effects on biochemical parameters of oxidative stress of the Spondias dulcis bark ethanolic extract on mice. The extract was evaluated in the doses of 500, 1000, and 1500 mg/kg bw via gavage. To evaluate the protective effects of the extract, benzo[a]pyrene (B[a]P) and cyclophosphamide (CP) were chosen as DNA damage inducers. Genotoxicity and antigenotoxicity were evaluated by the comet assay. Cytotoxicity, mutagenicity, and antimutagenicity were evaluated by the micronucleus test in bone marrow and peripheral blood. The biochemical parameters of oxidative stress were evaluated by the quantification of catalase activity (CAT) and reduced glutathione (GSH) in total blood, liver and kidney, and malondialdehyde (MDA), in liver and kidney. No genotoxic, cytotoxic, or mutagenic effect was found on mice exposed to the extract. The extract depleted the number of damaged nucleoids in total blood and the number of micronucleus (MN) in both cell types. The extract was able to increase CAT activity and GSH levels and decrease MDA levels after treatment with B[a]P and CP. The results indicate that the S. dulcis extract has potential to be used as preventive compound against DNA damage caused by CP and B[a]P.

An update on the mechanisms related to cell death and toxicity of doxorubicin and the protective role of nutrients

Doxorubicin (DOX), is a very effective chemotherapeutic agent against cancer whose clinical use is limited by toxicity. Different strategies have been proposed to attenuate toxicity, including combined therapy with bioactive compounds. This review update mechanisms of action and toxicity of doxorubicin and the role of nutrients like vitamins (A, C, E), minerals (selenium) and n-3 polyunsaturated fatty acids. Protective activities against DOX toxicity in liver, kidney, skin, bone marrow, testicles or brain have been reported, but these have not been evaluated for all of the reviewed nutrients. In most cases oxidation-related effects were present either, by reducing ROS levels and/or increasing antioxidant defenses. Antiapoptotic and anti-inflammatory mechanisms are also commonly reported. In some cases, interferences with autophagy and calcium homeostasis also have shown to be affected. Notwithstanding, there is a wide variety in duration and doses of treatment tested for both, compounds and DOX, which make difficult to compare the results of the studies. In spite of the reduction of DOX cardiotoxicity in health models, DOX anti-cancer activity in cancer cell lines or xenograft models usually did not result compromised when this has been evaluated. Importantly, clinical studies are needed to confirm all the observed effects.

Antioxidants as precision weapons in war against cancer chemotherapy induced toxicity - Exploring the armoury of obscurity

Cancer is the leading cause of mortality worldwide, accounting for almost 13% of deaths in the world. Among the conventional cancer treatments, chemotherapy is most frequently carried out to treat malignant cancer rather than localised lesions which is amenable to surgery and radiotherapy. However, anticancer drugs are associated with a plethora of side effects. Each drug, within every class, has its own set of adverse reactions which may cause patient incompliance and deterioration of the quality of life. One of the major causes of adverse reactions, especially for drugs targeting DNA, is the excessive production of reactive oxygen species (ROS) and subsequent build up of oxidative stress. To curb these undesired side effects, several dietary supplements have been tested, amongst which antioxidants have gained increasing popularity as adjuvant in chemotherapy. However, many oncologists discourage the use of antioxidant rich food supplements because these may interfere with the modalities which kill cancer by generating free radicals. In the present review, all studies reporting concomitant use of several antioxidants with chemotherapy are indiscriminately included and discussed impartially.

The effect of supplementation of thirteen different antioxidants and their analogues as a single agent or in combination with chemotherapy has been compiled in this article. The present review encompasses a total of 174 peer-reviewed original articles from 1967 till date comprising 93 clinical trials with a cumulative number of 18,208 patients, 56 animal studies and 35 in vitro studies. Our comprehensive data suggests that antioxidant has superior potential of ameliorating chemotherapeutic induced toxicity. Antioxidant supplementation during chemotherapy also promises higher therapeutic efficiency and increased survival times in patients.

Protective effects of curcumin against doxorubicin-induced toxicity and resistance: A review

Doxorubicin (DOX)-induced toxicity and resistance are major obstacles in chemotherapeutic approaches. Despite effective in the treatment of numerous malignancies, some clinicians have voiced concern that DOX has the potential to cause debilitating consequences in organ tissues, especially the heart. The mechanisms of toxicity and resistance are respectively related to induction of reactive oxygen species (ROS) and up-regulation of ATP-binding cassette (ABC) transporter. Curcumin (CUR) with several biological and pharmacological properties is expected to restore DOX-mediated impairments to tissues. This review is intended to address the current knowledge on DOX adverse effects and CUR protective actions in the heart, kidneys, liver, brain, and reproductive organs. Coadministration of CUR and DOX is capable of ameliorating DOX toxicity pertained to antioxidant, apoptosis, autophagy, and mitochondrial permeability.

Attenuation of doxorubicin-induced cardiotoxicity and genotoxicity by an indole-based natural compound 3,3'-diindolylmethane (DIM) through activation of Nrf2/ARE signaling pathways and inhibiting apoptosis

The most crucial complication related to doxorubicin (DOX) therapy is nonspecific cytotoxic effect on healthy normal cells. The clinical use of this broad-spectrum chemotherapeutic agent is restricted due to development of severe form of cardiotoxicity, myelosuppression, and genotoxicity which interfere with therapeutic schedule, compromise treatment outcome and may lead to secondary malignancy. 3,3'-diindolylmethane (DIM) is a naturally occurring plant alkaloid formed by the hydrolysis of indolylmethyl glucosinolate (glucobrassicin). Therefore, the present study was undertaken to investigate the protective role of DIM against DOX-induced toxicity in mice. DOX was administered (5 mg/kg b.w., i.p.) and DIM was administered (25 mg/kg b.w., p.o.) in concomitant and 15 days pretreatment schedule. Results showed that DIM significantly attenuated DOX-induced oxidative stress in the cardiac tissues by reducing the levels of free radicals and lipid peroxidation, and by enhancing the level of glutathione (reduced) and the activity of antioxidant enzymes. The chemoprotective potential of DIM was confirmed by histopathological evaluation of heart and bone marrow niche. Moreover, DIM considerably mitigated DOX-induced clastogenicity, DNA damage, apoptosis, and myeloid hyperplasia in bone marrow niche. In addition, oral administration of DIM significantly (p < .05) stimulated the Nrf2-mediated activation of antioxidant response element (ARE) pathway and promoted expression of ARE-driven cytoprotective proteins, HO-1, NQO1, and glutathione-S-transferase (GST). In connection with that, DIM significantly attenuated DOX-induced apoptosis by upregulation of Bcl-2 expression and downregulation of Bax and caspase-3 expression. Thus, this study suggests that DIM has promising chemoprotective efficacy against DOX-induced toxicity and indicates its future use as an adjuvant in chemotherapy.

Identifying Mazama gouazoubira (Artiodactyla; Cervidae) chromosomes involved in rearrangements induced by doxorubicin

The process of karyotype evolution in Cervidae from a common ancestor (2n = 70, FN = 70) has been marked by complex chromosomal rearrangements. This ancestral karyotype has been retained by the current species Mazama gouazoubira (Fischer 1814), for which a chromosomal polymorphism (Robertsonian translocations and the presence of B chromosomes) has been described, presumably caused by a chromosome fragility. Thus, this study has identified doxorubicin-induced chromosome aberrations and mapped the regions involved in breaks, which may be related to the chromosome evolution process. G-banding pattern showed that 21 pairs of chromosomes presented chromosomal aberrations, 60% of the total chromosome number of the species M. gouazoubira. Among chromosomes that carry aberrations, the region where they were most frequently concentrated was distal relative to the centromere. These data suggest that certain chromosomal regions may be more susceptible to chromosome fragility and consequently could be involved in karyotype differentiation in species of the family Cervidae.

Behavioral effects of Citrus limon and Punica granatum combinations in rats

Dietary supplements are becoming more influential as viable treatment for common chronic diseases and to promote normal development and functions of all system including brain. Disorders like anxiety and depression may be managed through healthier variations is dietary pattern, since there are indications that diet rich in antioxidants and vitamins diminish anxiety and depression. Hence this investigation was planned to assess the behavioral effects of Citrus limon and Punica granatum in two combination doses i.e. 0.4 + 5 ml/kg and 0.2 + 8 ml/kg C. limon and P. granatum respectively in rats. Antidepressant and anxiolytic effects were explicitly judged twice during 15 days using forced swimming and open field tests and elevated plus maze. In open field test C. limon and P. granatum showed increase in distance travelled, number of central entries and number of rearing's at 0.4 + 5 ml/kg combination, in the elevated plus maze, number of open arm entries were found to be augmented and in forced swimming test, there was decline in duration of immobility and rise in duration of climbing at both combinations i.e. 0.4 + 5 ml/kg and 0.2 + 8 ml/kg C. limon and P. granatum. These results suggest that C. limon and P. granatum at 0.4 + 5 ml/kg combination have anxiolytic and antidepressant effect.

In Vivo Effects of Vanadium Pentoxide and Antioxidants (Ascorbic Acid and Alpha-Tocopherol) on Apoptotic, Cytotoxic, and Genotoxic Damage in Peripheral Blood of Mice

This study was conducted to investigate the effects of vanadium pentoxide (V2O5), ascorbic acid (AA), and alpha-tocopherol (α-TOH) on apoptotic, cytotoxic, and genotoxic activity. Groups of five Hsd:ICR mice were treated with the following: (a) vehicle, distilled water; (b) vehicle, corn oil; (c) AA, 100 mg/kg intraperitoneally (ip); (d) α-TOH, 20 mg/kg by gavage; (e) V2O5, 40 mg/kg by ip injection; (f) AA + V2O5; and (g) α-TOH + V2O5. Genotoxic damage was evaluated by examining micronucleated polychromatic erythrocytes (MN-PCE) obtained from the caudal vein at 0, 24, 48, and 72 h after treatments. Induction of apoptosis and cell viability were assessed at 48 h after treatment in nucleated cells of peripheral blood. Treatment with AA alone reduced basal MN-PCE, while V2O5 treatment marginally increased MN-PCE at all times after injection. Antioxidants treatments prior to V2O5 administration decreased MN-PCE compared to the V2O5 group, with the most significant effect in the AA + V2O5 group. The apoptotic cells increased with all treatments, suggesting that this process may contribute to the elimination of the cells with V2O5-induced DNA damage (MN-PCE). The necrotic cells only increased in the V2O5 group. Therefore, antioxidants such as AA and α-TOH can be used effectively to protect or reduce the genotoxic effects induced by vanadium compounds like V2O5.

First evaluation of the antimutagenic effect of mangaba fruit in vivo and its phenolic profile identification

The chemical composition and functional effects of mangaba fruit pulp were evaluated through a multi-endpoint assay in mice, consisting of the bone marrow micronucleus test, gut micronucleus test, and the apoptosis, oxidative stress, and comet assays. Mangaba fruit pulp was administered in three doses, 10, 20, and 40ml/kg body weight (b.w.), by gavage to male Swiss mice against doxorubicin and dimethylhydrazine-induced mutagenicity. The phenolic profile of the mangaba fruit pulp was evaluated by HPLC, and seven compounds were identified: gallic acid, catechin, chlorogenic acid, vanillic acid, o-coumaric acid, rosmarinic acid, and rutin. The in vivo tests revealed that mangaba fruit pulp showed no toxic/mutagenic effects in any of the assays performed, and also showed protective effects at all endpoints. At the three administered extract concentrations, the main results about the protective effects were as follows: bone marrow micronucleus test (42.33, 58.14, and 77.21%), micronucleus gut test (34.21, 63.15, and 78.07%), and apoptosis index (57.5, 43.68, and 65.52%). This study provides scientific evidence for the antimutagenic potential of mangaba fruit pulp and emphasizes its potential as a functional food with widespread applicability in the food industry.

Behavioral effects of Citrus limon in rats

Anxiety and depression are increasing worldwide, however these disorders may be managed by making healthier changes is dietary pattern, since there are evidences that diet rich in antioxidants and vitamins help reduce anxiety and depression. Hence present study was designed to evaluate the behavioral effects of Citrus limon in rats at three different doses i.e. 0.2, 0.4 and 0.6 ml/kg considered as low, moderate and high doses. Anxiolytic and antidepressant activities were specifically assessed twice during 15 days using open field test, elevated plus maze and forced swimming test. In open field test C. limon, revealed increase in distance travelled, number of central entries and number of rearing's at moderate dose, while in the elevated plus maze, number of open arm entries were found to be increased. Whereas in forced swimming test, there was decrease in duration of immobility and increase in duration of climbing. Thus results of present study suggest that C. limon at moderate dose have anxiolytic effect.

Iron induced genotoxicity: attenuation by vitamin C and its optimization

Vitamin C (VC) is a well-known antioxidant and strong free radical scavenger. Its antioxidant activity is useful for protection of cellular macromolecules, particularly DNA, from oxidative damage induced by different agents. This study was undertaken to evaluate the optimum level of VC in attenuating the chromosome aberrations (CAs) and DNA damage after iron sulfate (FeSO4) acute administration in Wistar rats. The results exhibited that the increase of CAs and DNA damage induced by FeSO4, 200 mg Fe/kg, could be reduced significantly by VC pretreatment at the dose of 500 mg/kg (p<0.001), but not in the 100 mg/kg group. The findings provide evidence that VC at the dose of 500 mg/kg exerted a possible protective effect against FeSO4 induced CAs and DNA damage. The possible mechanisms of VC may be attributed to its property as a free radical scavenger or to its indirect action in reducing the level of reactive oxygen species (ROS).

Effects of lutein and chlorophyll b on GSH depletion and DNA damage induced by cisplatin in vivo

Recent studies have proposed the use of low concentrations of phytochemicals and combinations of phytochemicals in chemoprevention to reduce cytotoxicity and simulate normal ingestion through diet. The purpose of the present study was to evaluate whether the DNA damage, chromosome instability, and oxidative stress induced by cisplatin (cDDP) are modulated by a combination of the natural pigments lutein (LT) and chlorophyll b (CLb). The protective effects observed for synergism between phytochemicals have not been completely investigated. The comet assay and micronucleus test were performed and the catalase activities and glutathione (GSH) concentrations were measured in the peripheral blood, bone marrow, liver, and kidney cells of mice. The comet assay and micronucleus test results revealed that the pigments LT and CLb were not genotoxic or mutagenic and that the pigments presented antigenotoxic and antimutagenic effects in the different cell types evaluated. This protective effect is likely related to antioxidant properties in peripheral blood cells through the prevention of cDDP-induced GSH depletion. Altogether our results show that the combination of LT and CLb, which are both usually present in the same foods, such as leafy green vegetables, can be used safely.

Oxidative stress on cardiotoxicity after treatment with single and multiple doses of doxorubicin

The mechanism of doxorubicin (DOX)-induced cardiotoxicity remains controversial. Wistar rats ( n = 66) received DOX injections intraperitoneally and were randomly assigned to 2 experimental protocols: (1) rats were killed before (−24 h, n = 8) and 24 h after (+24 h, n = 8) a single dose of DOX (4 mg/kg body weight) to determine the DOX acute effect and (2) rats ( n = 58) received 4 injections of DOX (4 mg/kg body weight/week) and were killed before the first injection (M0) and 1 week after each injection (M1, M2, M3, and M4) to determine the chronological effects. Animals used at M0 ( n = 8) were also used at moment −24 h of acute study. Cardiac total antioxidant performance (TAP), DNA damage, and morphology analyses were carried out at each time point. Single dose of DOX was associated with increased cardiac disarrangement, necrosis, and DNA damage (strand breaks (SBs) and oxidized pyrimidines) and decreased TAP. The chronological study showed an effect of a cumulative dose on body weight ( R = −0.99, p = 0.011), necrosis ( R = 1.00, p = 0.004), TAP ( R = 0.95, p = 0.049), and DNA SBs ( R = −0.95, p = 0.049). DNA SBs damage was negatively associated with TAP ( R = −0.98, p = 0.018), and necrosis ( R = −0.97, p = 0.027). Our results suggest that oxidative damage is associated with acute cardiotoxicity induced by a single dose of DOX only. Increased resistance to the oxidative stress is plausible for the multiple dose of DOX. Thus, different mechanisms may be involved in acute toxicity versus chronic toxicity.

Antimutagenic and antirecombinagenic activities of noni fruit juice in somatic cells of Drosophila melanogaster

Noni, a Hawaiian name for the fruit of Morinda citrifolia L., is a traditional medicinal plant from Polynesia widely used for the treatment of many diseases including arthritis, diabetes, asthma, hypertension and cancer. Here, a commercial noni juice (TNJ) was evaluated for its protective activities against the lesions induced by mitomycin C (MMC) and doxorrubicin (DXR) using the Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster. Three-day-old larvae, trans-heterozygous for two genetic markers (mwh and flr3 ), were co-treated with TNJ plus MMC or DXR. We have observed a reduction in genotoxic effects of MMC and DXR caused by the juice. TNJ provoked a marked decrease in all kinds of MMC- and DXR-induced mutant spots, mainly due to its antirecombinagenic activity. The TNJ protective effects were concentration-dependent, indicating a dose-response correlation, that can be attributed to a powerful antioxidant and/or free radical scavenger ability of TNJ.

Antioxidative and antigenotoxic effect of vitamin E against patulin cytotoxicity and genotoxicity in HepG2 cells

Patulin (PAT) is a mycotoxin produced in fruits, mainly in apples, by certain species of Penicillium, Aspergillus, and Byssochlamys. It has been shown that PAT is cytotoxic, genotoxic, and mutagenic in different cell types. Several studies incriminate the oxidative stress as a mechanism of PAT-mediated toxicity. In this context, our aim was to investigate the protective role of Vitamin E (Vit E), an antioxidant agent, against PAT induced cytotoxicity and genotoxicity in cultured HepG2 cells. The obtained results showed that addition of Vit E in cells treated with PAT significantly reduce cell mortality induced by this toxin. In the same conditions, Vit E decreased the intracellular level of ROS, reduced PAT induced p53 expression, and reversed PAT induced DNA damage. In addition, Vit E prevented significantly the percentage of chromosome aberrations induced by PAT in HepG2 cells in a concentration dependant manner. These results suggest that Vit E, an exogenous antioxidant agent, plays an important role in defense against PAT-induced cytotoxicity and genotoxicity, which confirms the involvement of oxidative stress in the induction of DNA damage by PAT in HepG2 cells.

Genotoxicity assessment of Copaiba oil and its fractions in Swiss mice

Copaiba oil-resin, extracted from the trunk of Copaifera, and traditionally used in folk medicine in the treatment of various disorders, has been shown to be an effective antiinflamatory, antitumor, antitetanus, antiseptic and anti-blenorrhagea agent. As, there are few studies evaluating its genotoxicity, this aspect of the commercial oil-resin, and its volatile and resinous fractions, were evaluated in mice by comet assay and micronucleus (MN) test. A single dose of oil resin, volatile or resin fractions (500; 1,000 or 2,000 mg/kg b.w.) was administered by gavage. The chemical compositions of Copaiba oil resin and its fractions was analyzed by gas chromatography. According to comet assaying, treatment with either one did not increase DNA damage, and as to MN testing, there was no alteration in the incidence of micronucleated polychromatic erythrocytes. Chromatographic analysis of the oil-resin itself revealed sesquiterpenes, diterpenic carboxylic acid methyl esters and high levels of β-caryophyllene. Thus, it can be assumed that the oil resin and volatile and resinous fractions from the commercial product are not genotoxic or mutagenic.

Cardioprotective Activity of Methanol Extract of fruit of Trichosanthes cucumerina on Doxorubicin-induced Cardiotoxicity in Wistar Rats

AIM AND OBJECTIVE

The objective was to determine the activity of methanol extract of fruit of Trichosanthes cucumerina in doxorubicin-induced cardiotoxicity in rats.

MATERIALS AND METHODS

The methanol extract of fruit of T. cucumerina was prepared. Male Wistar rats were divided in four groups. Group I was vehicle control. Group II animals received doxorubicin 4 mg/kg i.p. on days 21, 28, 35, and 42. Group III and IV animals were treated with methanol extract of T. cucumerina (500 and 1000 mg/kg, respectively) for 49 days. Doxorubicin was administered on days 21, 28, 35, and 42 days. The parameters of study were body weight, serum biomarkers, ECG, blood pressure, and left ventricular function. At the end of the study, the histology of heart, liver, and kidney was carried out.

RESULTS

Cardiac toxicity by doxorubicin was manifested as body weight loss, elevated serum LDH and CK-MB, increased ST, QT and QRS complex, reduced blood pressure, and left ventricular function. The methanol extract of T. cucumerina significantly decreased LDH and CK-MB, reduced ST, QT interval and QRS complex, increased heart rate, restored blood pressure, and left ventricular function. Doxorubicin caused liver and kidney necrosis, cellular infiltration, and vascular changes that indicated injury.

CONCLUSION

T. cucumerina (1000 mg/kg) reduced the severity of doxorubicin-induced cardiac damage especially in heart. It is concluded that doxorubicin-induced cardiotoxicity is reduced by pretreatment with methanol extract of fruit of T. cucumerina.

An evaluation, using the comet assay and the micronucleus test, of the antigenotoxic effects of chlorophyll b in mice

We investigated the effects of the dietary pigment chlorophyll b (CLb) on cisplatin (cDDP)-induced oxidative stress and DNA damage, using the comet assay in mouse peripheral blood cells and the micronucleus (MN) test in bone marrow and peripheral blood cells. We also tested for thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) in liver and kidney tissues, as well as catalase (CAT) activity and GSH in total blood. CLb (0.2 and 0.5mg/kg b.w.) was administrated by gavage every day for 13 days. On the 14th day of the experiment, 6 mg/kg cDDP or saline was delivered intraperitoneally. Treatment with cDDP led to a significant decrease in DNA migration and an increase in MN frequency in both cell types, bone marrow and peripheral blood cells. In the kidneys of mice treated with cDDP, TBARS levels were increased, whereas GSH levels were depleted in kidney and liver. In mice that were pre-treated with CLb and then treated with cDDP, TBARS levels maintained normal concentrations and GSH did not differ from cDDP group. The improvement of oxidative stress biomarkers after CLb pre-treatment was associated with a decrease in DNA damage, mainly for the highest dose evaluated. Furthermore, CLb also slightly reduced the frequency of chromosomal breakage and micronucleus formation in mouse bone marrow and peripheral blood cells. These results show that pre-treatment with CLb attenuates cDDP-induced oxidative stress, chromosome instability, and lipid peroxidation.

Different responses to doxorubicin-induced chromosome aberrations in Brazilian deer species

The tendency toward chromosome fragility is one of the theories that may explain chromosome variation in brocket deer species (genus Mazama). We tested doxorubicin as an inducer of chromosome aberrations in lymphocytes of three brocket deer species, Mazama gouazoubira, M. americana and M. nana, compared to the marsh deer, Blastocerus dichotomus. Doxorubicin, at a concentration of 0.25 microg/mL, induced chromosome aberrations and fragile sites in all four species; the highest frequencies were seen in M. gouazoubira; they were lowest in B. dichotomus and intermediate in M. americana and M. nana. These results were expected based on previous karyotypic studies, but they failed to explain the higher sensitivity seen in M. gouazoubira. This may be because not all the aberrations and fragile sites are related to chromosome evolution in brocket deer; other factors, such as environmental influences, may be involved in chromosome fragility.

Oxidative stress induced by atrazine in rat erythrocytes: mitigating effect of vitamin E

The present study investigates the propensity of atrazine to induce oxidative stress and its possible attenuation by vitamin E in rat erythrocytes, which is a convenient model to understand the oxidative damage induced by various xenobiotics. Experimental animals were administered atrazine (300 mg/kg body weight, daily) and/or vitamin E (100 mg/kg body weight, daily) orally for a period of 7, 14, and 21 days. Results indicated that the reduced glutathione (GSH) content of the erythrocytes of atrazine treated rats was significantly decreased as compared to the control group. Co-administration of vitamin E along with atrazine restored the GSH content of erythrocytes nearly to control levels. The activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione-s-transferase were found to be increased significantly in the erythrocytes accompanied by a decrease in the activity of the glucose-6-phosophate dehydrogenase, following atrazine exposure. On the other hand, when vitamin E was co-administered along with atrazine, activities of these enzymes were found to be restored significantly. In conclusion, results of the study demonstrated that atrazine induced oxidative stress in rat erythrocytes, in terms of increased activities of the various antioxidant enzymes, and decreased content of reduced glutathione. However, vitamin E administration ameliorated the effects of atrazine, suggesting that vitamin E is a potential antioxidant against atrazine-induced oxidative stress.

Evaluation of the genotoxic and antigenotoxic effects after acute and subacute treatments with açai pulp (Euterpe oleracea Mart.) on mice using the erythrocytes micronucleus test and the comet assay

Açai, the fruit of a palm native to the Amazonian basin, is widely distributed in northern South America, where it has considerable economic importance. Whereas individual polyphenolics compounds in açai have been extensively evaluated, studies of the intact fruit and its biological properties are lacking. Therefore, the present study was undertaken to investigate the in vivo genotoxicity of açai and its possible antigenotoxicity on doxorubicin (DXR)-induced DNA damage. The açai pulp doses selected were 3.33, 10.0 and 16.67g/kg b.w. administered by gavage alone or prior to DXR (16mg/kg b.w.) administered by intraperitoneal injection. Swiss albino mice were distributed in eight groups for acute treatment with açai pulp (24h) and eight groups for subacute treatment (daily for 14 consecutive days) before euthanasia. The negative control groups were treated in a similar way. The results of chemical analysis suggested the presence of carotenoids, anthocyanins, phenolic, and flavonoids in açai pulp. The endpoints analyzed were micronucleus induction in bone marrow and peripheral blood cells polychromatic erythrocytes, and DNA damage in peripheral blood, liver and kidney cells assessed using the alkaline (pH >13) comet assay. There were no statistically significant differences (p>0.05) between the negative control and the groups treated with the three doses of açai pulp alone in all endpoints analyzed, demonstrating the absence of genotoxic effects. The protective effects of açai pulp were observed in both acute and subacute treatments, when administered prior to DXR. In general, subacute treatment provided greater efficiency in protecting against DXR-induced DNA damage in liver and kidney cells. These protective effects can be explained as the result of the phytochemicals present in açai pulp. These results will be applied to the developmental of food with functional characteristics, as well as to explore the characteristics of açai as a health promoter.

Oxidative and genotoxic damage after radio‐iodine therapy of Graves' hyperthyroidism

PURPOSE

To evaluate genetic damage and oxidative stress following a single therapeutic dose of 131I in Graves' disease patients monitored up to 180 days after treatment.

MATERIALS AND METHODS

Genetic damage induction was estimated as the increase in micronuclei in peripheral lymphocytes of patients. As indicators of radiogenic oxidative stress, vitamin E and lipoperoxide levels were assessed in the plasma of patients, as well as the release of plasmic clastogenic factors measured by the induction of micronuclei in vitro in peripheral lymphocytes of a healthy donor.

RESULTS

Vitamin E depletion lasted at least 3 days and the basal level was restored within 7 days. No statistically significant variations were observed in lipoperoxide plasma levels. A sharp increase of micronuclei in the peripheral lymphocytes of patients was correlated (p < 0.001) with the release of clastogenic factor in the plasma. The highest micronucleus value was negatively correlated (p < 0.03) with the lowest vitamin E level observed in each patient.

CONCLUSIONS

Micronuclei induction was the direct consequence not only of the energy deposition of 131I on the genetic material, but also of oxidative stress, likely via the release of clastogenic factor.

Effect of organic tomato (Lycopersicon esculentum) extract on the genotoxicity of doxorubicin in the Drosophila wing spot test

The consumption of organic tomatoes (ORTs) reduces the risk of harmful effects to humans and the environment caused by exposure to toxic agrochemicals. In this study, we used the somatic mutation and recombination test (SMART) of wing spots in Drosophila melanogaster to evaluate the genotoxicity of ORT and the effect of cotreatment with ORT on the genotoxicity of Doxorubicin^® (DXR, a cancer chemotherapeutic agent) that is mediated by free radical formation. Standard (ST) cross larvae were treated chronically with solutions containing 25%, 50% or 100% of an aqueous extract of ORT, in the absence and presence of DXR (0.125 mg/mL), and the number of mutant spots on the wings of emergent flies was counted. ORT alone was not genotoxic but enhanced the toxicity of DXR when administered concomitantly with DXR. The ORT-enhanced frequency of spots induced by DXR may have resulted from the interaction of ORT with the enzymatic systems that catalyze the metabolic detoxification of this drug.

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.

The genotoxicity of vitamin C in vitro

The genotoxic effects of Vitamin C (ascorbic acid) on human lymphocytes in vitro were estimated by analyzing and identifying various chromosome abnormalities, in relation to the concentration of Vitamin C. Testing concentrations of Vitamin C induced different aberrations including the impairment of spindle function. The spindle disturbances can result in mitotic arrest, multipolar spindles and multipolar segregation, errors in chromosome segregation, formation of chromosome bridges and chromosome laggards. The most frequent irregularities were found in anaphase and telophase. A certain number of lymphocytes were arrested at anaphase or telophase (in colchicine-untreated cultures of human lymphocytes). Testing concentrations of ascorbic acid did not induce a significant increase in the number of aneuploid mitoses and were not clastogenic except at the highest concentration (1,000 microg/ml) in colchicine-treated cultures, and in colchicine-untreated cultures of human lymphocytes the pulverization of chromosome was observed. Vitamin C changed the mitotic index value of lymphocytes notably at the higher concentrations (250, 500 and 1,000 microg/ml).

Protective effects of vitamin E against atrazine-induced genotoxicity in rats

Atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) is one of the most commonly used herbicides to control grasses and weeds. The widespread contamination and persistence of atrazine residues in the environment has resulted in human exposure. Vitamin E is a primary antioxidant that plays an important role in protecting cells against toxicity by inactivating free radicals generated following pesticides exposure. The present study was undertaken to investigate the protective effect of vitamin E against atrazine-induced genotoxicity. Three different methods: gel electrophoresis, comet assay and micronucleus test were used to assess the atrazine-induced genotoxicity and to evaluate the protective effects of vitamin E. Atrazine was administered to male rats at a dose of 300 mg/kg body weight for a period of 7, 14 and 21 days. There was a significant increase (P<0.001) in tail length of comets from blood and liver cells treated with atrazine as compared to controls. Co-administration of vitamin E (100 mg/kg body weight) along with atrazine resulted in decrease in tail length of comets as compared to the group treated with atrazine alone. Micronucleus assay revealed a significant increase (P<0.001) in the frequency of micronucleated cells (MNCs) following atrazine administration. In the animals administrated vitamin E along with atrazine there was a significant decrease in percentage of micronuclei as compared to atrazine treated rats. The increase in frequency of micronuclei in liver cells and tail length of comets confirm genotoxicity induced by atrazine in blood and liver cells. In addition, the findings clearly demonstrate protective effect of vitamin E in attenuating atrazine-induced DNA damage.

Protection of multiple antioxidants Chinese herbal medicine on the oxidative stress induced by adriamycin chemotherapy

Adriamycin is an effective anthracycline anti-tumor antibiotic. However, the clinical use of adriamycin has been restricted by its serious side effects. Some reports indicated that the side effects of adriamycin could cause systemic injury, in which reactive oxygen species (ROS) play an important role. ROS are a large family of oxygen free radical and non-free radical active oxygen-containing molecules, including superoxide radical, hydrogen peroxide and hydroxyl radical, which contribute to oxidative stress. Although antioxidant treatment is a promising method to prevent the side effects, protection by a single antioxidant is limited. The Chinese herbal medicine ANTIOXIN is a multiple antioxidant that can effectively block oxidative stress. It was hypothesized that ANTIOXIN could effectively reduce the side effects of adriamycin. A rat tumor model with a transplanted tumor in the liver was treated with adriamycin and ANTIOXIN was used as a protection. Oxidative stress and antioxidant enzymes were evaluated. The results showed that adriamycin chemotherapy increased the level of malondialdehyde (MDA), nitrogen oxide (NO) and decreased the activities of total superoxide dismutase (T-SOD), manganese superoxide dismutase (MnSOD), catalase (CAT), glutathione (GSH) and total antioxidant capacity (TAC). Adriamycin chemotherapy also decreased the expression of Bcl-2, increased the expression of iNOS and cell apoptosis in the liver and kidney. Multiple antioxidants ANTIOXIN had an antagonistic effect on these changes and significantly decreased the mortality of the experimental rats. These data demonstrated that adriamycin chemotherapy could cause oxidative stress to the whole body, on which multiple antioxidants based on the theory of 'multiple antioxidant chain' had effective protection.

Doxorubicin as an antioxidant: maintenance of myocardial levels of lycopene under doxorubicin treatment

The mechanism of doxorubicin-induced cardiotoxicity remains controversial. Wistar rats (n=96) were randomly assigned to a control (C), lycopene (L), doxorubicin (D), or doxorubicin+lycopene (DL) group. The L and DL groups received lycopene (5 mg/kg body wt/day by gavage) for 7 weeks. The D and DL groups received doxorubicin (4 mg/kg body wt intraperitoneally) at 3, 4, 5, and 6 weeks and were killed at 7 weeks for analyses. Myocardial tissue lycopene levels and total antioxidant performance (TAP) were analyzed by HPLC and fluorometry, respectively. Lycopene metabolism was determined by incubating (2)H(10)-lycopene with intestinal mucosa postmitochondrial fraction and lipoxygenase and analyzed with HPLC and APCI mass spectroscopy. Myocardial tissue lycopene levels in DL and L were similar. TAP adjusted for tissue protein were higher in myocardium of D than those of C (P=0.002). Lycopene metabolism study identified a lower oxidative cleavage of lycopene in D as compared to those of C. Our results showed that lycopene was not depleted in myocardium of lycopene-supplemented rats treated with doxorubicin and that higher antioxidant capacity in myocardium and less oxidative cleavage of lycopene in intestinal mucosa of doxorubicin-treated rats suggest an antioxidant role of doxorubicin rather than acting as a prooxidant.

Tomato-oleoresin supplement prevents doxorubicin-induced cardiac myocyte oxidative DNA damage in rats

Doxorubicin (DOX) is an efficient chemotherapeutic agent used against several types of tumors; however, its use is limited due to severe cardiotoxicity. Since it is accepted that reactive oxygen species are involved in DOX-induced cardiotoxicity, antioxidant agents have been used to attenuate its side effects. To determine tomato-oleoresin protection against cardiac oxidative DNA damage induced by DOX, we distributed Wistar male rats in control (C), lycopene (L), DOX (D) and DOX+lycopene (DL) groups. They received corn oil (C, D) or tomato-oleoresin (5mg/kg body wt. day) (L, DL) by gavage for a 7-week period. They also received saline (C, L) or DOX (4mg/kg body wt.) (D, DL) intraperitoneally at the 3rd, 4th, 5th, and at 6th week. Lycopene absorption was checked by HPLC. Cardiac oxidative DNA damage was evaluated by the alkaline Comet assay using formamidopyrimidine-DNA glycosylase (FPG) and endonuclease III (endo III). Cardiomyocyte levels of SBs, SBs FPG and SBs Endo III were higher in rats from D when compared to other groups. DNA damage levels in cardiomyocytes from DL were not different when compared to C and L groups. The viability of cardiomyocytes from D or DL was lower than C or L groups (p<0.01). Lycopene levels (mean+/-S.D.nmol/kg) in saponified hearts were similar between L (47.43+/-11.78) and DL (49.85+/-16.24) groups. Our results showed: (1) lycopene absorption was confirmed by its cardiac levels; (2) DOX-induced oxidative DNA damage in cardiomyocyte; (3) tomato-oleoresin supplementation protected against cardiomyocyte oxidative DNA damage.

Salubrious effects of lipoic acid against adriamycin-induced clastogenesis and apoptosis in Wistar rat bone marrow cells

Adriamycin (ADR), an anthracycline antibiotic, which is widely used as an antineoplastic drug in the treatment of various solid tumors, has been shown to induce genotoxicity in erythropoietic system. The aim of the present study was to investigate the protective efficacy of DL-alpha-lipoic acid (LA) on ADR-induced clastogenicity and apoptosis in the bone marrow of rats. The animals were randomly divided into eight groups consisting of six rats each. Five groups were administered ADR (20 mg/kg body weight, i.v.) to induce genotoxicity; four of these groups received a single intraperitoneal injection of LA at a dose of either 100 or 200 mg/kg body weight, and either 30 or 60 min prior to ADR administration. A vehicle treated control group and LA control groups were also included. The beneficial effects of LA were monitored by DNA strand breaks, chromosomal aberrations, micronucleus assay and apoptotic studies in the bone marrow cells of rats after 24 h following single dose of ADR treatment. ADR treatment caused significant clastogenicity and apoptosis in rat bone marrow cells. The treatment with LA showed significant reduction in the frequency of chromosomal aberrations, DNA strand breaks and apoptosis in bone marrow cells as well as decreased the micronuclei formation in bone marrow and peripheral blood of rats treated with ADR. The protective effect of LA was found to be stronger at a dose of 200 mg/kg body weight than 100 mg/kg body weight dosage with respect to the above results, indicating the dose dependent effect of LA. However, the protection by LA was not dependent on the time intervals between LA and ADR administration. The results of this study illustrate the protective effect of LA on ADR-induced clastogenicity and apoptosis in the erythropoietic system of rats.

Protective effects of a mixture of antioxidant vitamins and minerals on the genotoxicity of doxorubicin in somatic cells of Drosophila melanogaster

Antioxidant vitamins are able to deactivate highly bioactive molecules, such as free radicals, that are generated during cellular biochemical processes. Doxorubicin (DXR) is a cancer chemotherapeutic agent that generates free radicals as a byproduct. In the present study, the Drosophila melanogaster somatic wing spot test was used to evaluate the effects of a mixture of vitamins (Vitamins C, E, and beta-carotene) and minerals (copper, selenium, and zinc), commercially known as Vitergan Zinc Plus, on the genotoxicity of DXR in standard and high-bioactivation crosses of flies. 12.5, 25, and 50 mg/ml of the vitamin/mineral mixture by itself was nongenotoxic in the trans-heterozygous descendants of both crosses, while the mixture produced a significant reduction in the genotoxicity produced by 0.125 mg/ml DXR in the trans-heterozygous descendants of both crosses. The protective effect was observed when the larvae received either pre- or cotreatments of the multivitamin/mineral (MV) mixture. The results indicate that, under these experimental conditions, the MV mixture is not genotoxic; however, it protects against the genotoxic effects of the chemotherapeutic free-radical generator DXR.

Effects of 10alpha,25-dihydroxyvitamin D3 on doxorubicin-induced chromosomal aberrations in rat bone marrow cells

The present study was carried out to evaluate the effects of 1alpha,25-dihydroxyvitamin D3 (VD) on chromosomal aberrations induced by doxorubicin (DXR). Wistar rats were divided into eight experimental groups of five animals each. Control group animals were treated with i.p. distilled water. The animals in three VD groups were given only VD for 4, 6 or 8 weeks. In the DXR groups the animals were given only DXR. In the combination groups VD doses were given for 4, 6 or 8 weeks for each group and DXR was injected 24 h before sacrificing the rats. DXR (50 mg/100 g b.w.) was injected intraperitoneally and VD by gavage 3 microg/kg/day twice weekly. Animals treated with both VD and DXR showed a low frequency of chromosomal aberrations and abnormal metaphases when compared with animals treated with DXR alone (p < 0.0001). The numbers of both chromosomal aberrations and abnormal metaphases were similar in weeks 6 and 8 (p > 0.05) and lower than those in week 4 for the VD groups (p < 0.0001). Under the present experimental conditions, the efficiency of VD in protecting cells against DXR-induced chromosome damage was found to be dose dependent. The protective effects of VD on chromosome aberrations induced by DXR are discussed in the light of literature data.

Evaluation of the genotoxic potential of the Casearia sylvestris extract on HTC and V79 cells by the comet assay

Casearia sylvestris is common in tropical America growing wild in Brazil in the states of Amazonas and São Paulo. Its leaves are used in Brazilian folk medicine for several diseases. The present investigation was carried out to examine the genotoxic effects of a C. sylvestris crude ethanolic extract on Hepatoma Tissue Culture (HTC cells) of Rattus norvegicus and Chinese hamster V79 cells in culture, using the comet assay. For the genotoxic evaluation the cells were treated with three different concentrations (0.5, 1 and 2 mg/ml) of extract prepared from a 25 mg/ml aqueous solution. The positive control was cyclophosphamide for HTC cells and methyl methanesulfonate for V79 cells. The duration of the treatment was 2 h. The results showed that the extract of C. sylvestris presented no genotoxic effects and not modified effect inducing DNA damage by alkylating agents cyclophosphamide and methyl methanesulfonate in HTC and V 79 cells respectively.