Effect of oral selenium administration on cisplatin-induced nephrotoxicity in rats

Inhibition of thioredoxin reductase 1 correlates with platinum-based chemotherapeutic induced tissue injury

Platinum-containing drugs (PtDs; e.g. cisplatin, carboplatin, and oxaliplatin) have been widely used as anticancer reagents against various cancers. However, treatment with these drugs results in undesirable adverse effects with unknown mechanisms. Herein, we found a strong correlation between the inhibitory effects of PtDs on cytosolic thioredoxin reductase (TXNRD1) and tissue injury. Of the PtDs tested, cisplatin was found to be the most effective inhibitory PtD against TXRND1, causing the severest kidney injury. The initial inhibition of TXNRD1 in the kidney resulted from cisplatin-induced transcriptional activation of Nrf2-regulated genes including Txnrd1. However, the antioxidant responses in the kidney did not reverse the cisplatin-induced oxidation process. Nephrotoxicity was accompanied with an increase of protein glutathionylation and a cellular thiol redox environment oxidation. These results suggest that the changes of the cellular thiol-dependent redox environment regulated by TXNRD1 is a major event in the adverse effects of cisplatin in kidney.

The Interaction of Selenium with Chemotherapy and Radiation on Normal and Malignant Human Mononuclear Blood Cells

Selenium, a trace element with anticancer properties, can reduce harmful toxicities of chemotherapy and radiotherapy without compromising efficacy. However, the dose-response relationship in normal versus malignant human cells is unclear. We evaluated how methylseleninic acid (MSA) modulates the toxicity and efficacy of chemotherapy and radiation on malignant and non-malignant human mononuclear blood cells in vitro. We specifically investigated its effects on endoplasmic reticulum stress induction, intracellular glutathione concentration, DNA damage and viability of peripheral blood mononuclear cells and THP1 monocytic leukaemia cells in response to radiation, cytosine arabinoside or doxorubicin chemotherapy. MSA, at lower concentrations, induced protective responses in normal cells but cytotoxic effects in malignant cells, alone and in conjunction with chemotherapy or radiation. However, in normal cells higher concentrations of MSA were directly toxic and increased the cytotoxicity of radiation but not chemotherapy. In malignant cells higher MSA concentrations were generally more effective in combination with cancer treatments. Thus, optimal MSA concentrations differed between normal and malignant cells and treatments. This work supports clinical reports that selenium can significantly reduce dose-limiting toxicities of anticancer therapies and potentially improve efficacy of anticancer treatments. The optimal selenium compound and dose is not yet determined.

In vivo antitumour potential of camel's milk against hepatocellular carcinoma in rats and its improvement of cisplatin renal side effects

CONTEXT

Camel milk (CM) is recommended for liver disease patients in Egypt for a strong belief that it has a curative effect.

OBJECTIVE

The effect of consumption of CM with or without chemotherapeutic drug cisplatin was evaluated on induced hepatocarcinogenesis in rats.

MATERIALS AND METHODS

Wistar male rats (56) were divided into eight groups (7 rats each). Group I was control. Hepatocarcinogenesis was initiated by a single dose of intraperitoneal injection of diethylnitrosamine (DENA) (200 mg/kg BW) and promoted by phenobarbitone (500 ppm) in drinking water in groups V, VI, VII and VIII. Treatment started from 28th till 38th week using CM (5 mL/day) and/or cisplatin (5 mg/kg/3 weeks) in groups II, III IV, VI, VII and VIII. Biochemical analysis, lipid peroxidation and superoxide dismutase (SOD) activity in liver tissue were performed. Histopathology of liver and kidney and immunohistochemistry of placental glutathione-S-transferase (P-GST) in liver were performed and analyzed using image analysis.

RESULTS

Albumin concentration and SOD activity were 3.13 ± 0.23 and 311.45 ± 41.71 in group VII (DENA & cisplatin), whereas they were 4.3 ± 0.15 and 540.5 ± 29.94 in group VII (DENA, CM and cisplatin). The mean area of altered hepatocellular foci and P-GST altered foci decreased in group VI (DENA and CM) (1049.6 ± 174.78 and 829.1 ± 261) and group VIII (cisplatin and CM) (1615.12 ± 436 and 543.9 ± 127) compared to group V (DENA only) (4173.74 ± 510.7 and 3169.49 ± 538.61). Cisplatin caused chronic interstitial nephritis, which was slightly alleviated in group VIII (CM and cisplatin).

CONCLUSIONS

CM had an antioxidant effect and together with cisplatin managed to decrease hepatocarcinogenesis.

Cisplatin-Induced Nephrotoxicity; Protective Supplements and Gender Differences

Cisplatin (CDDP) has been widely used as a chemotherapeutic agent for solid tumors. The most common side effect of CDDP is nephrotoxicity, and many efforts have been made in the laboratory and the clinic to employ candidate adjuvants to CDDP to minimize this adverse influence. Many synthetic and herbal antioxidants as well as trace elements have been investigated for this purpose in recent years and a variety of positive and negative results have been yielded. However, no definitive supplement has so far been proposed to prevent CDDP-induced nephrotoxicity; however, this condition is gender related and the sex hormone estrogen may protect the kidney against CDDP damage. In this review, the results of research related to the effect of different synthetic and herbal antioxidants supplements are presented and discussed with suggestions included for future work.

Effects of combination therapy of docetaxel with selenium on the human breast cancer cell lines MDA-MB-231 and MCF-7

Purpose

The anticancer property and cytoprotective role of selenium in chemotherapy have been reported. However, the combination effects of selenium on chemotherapy for advanced breast cancer have not yet been clearly defined. The purpose of this study was to investigate the combined effects of selenium on chemotherapy using docetaxel on breast cancer cell lines.

Methods

Under adherent culture conditions, two breast cancer cell lines, MDA-MB-231 and MCF-7, were treated with docetaxel at 500pM and selenium at 100nM, 1µM, or 10µM. Changes in cell growth, cell cycle duration, and degree of apoptosis after 72 hours in each treated group were evaluated.

Results

In the MDA-MB-231 cells, the combination therapy group (docetaxel at 500pM plus selenium at 10µM) showed a significantly decreased percentage of cell growth (15% vs. 28%; P = 0.004), a significantly increased percentage of late apoptosis (63% vs. 26%; P = 0.001), and an increased cell cycle arrest in the G2/M phase (P = 0.001) compared with the solitary docetaxel therapy group. Isobologram analysis demonstrated the synergistic effect of the combination therapy in the MDA-MB-231 cells. However, in the MCF-7 cells, no significant differences in the percentage of cell growth apoptosis, the percentage of apoptosis, and the pattern of cell cycle arrest were noted between the combination therapy groups and the solitary docetaxel therapy group.

Conclusion

Our in vitro study indicated that the combination of selenium with docetaxel inhibits cell proliferation through apoptosis and cell arrest in the G2/M phase in MDA-MB-231 breast cancer cells.

Nephroprotective and curative effects of Ficus religiosa latex extract against cisplatin-induced acute renal failure

CONTEXT

Ficus religiosa L. (Moraceae) is widely planted in the tropics. Its chemical constituents include tannin, saponin gluanol acetate, β-sitosterol, leucoanthocyanidin and leucoanthocyanin which are used for the treatment of pain, inflammation, impotence, menstrual disturbances, uterine tonic and urine related problems.

OBJECTIVE

To determine the possible nephroprotective and curative effects of F. religiosa latex methanol extract against cisplatin induced acute renal failure.

MATERIALS AND METHODS

Methanol extract was obtained by maceration process. Rats were divided in five groups. Group 1 was administered acacia (2% w/v) of 5 ml/kg throughout the experiment; group 2 was treated with single dose of cisplatin (5 mg/kg i.p.) on the 1st day; group 3 (200 mg/kg p.o.) of extract control for the 1st to 10th day, group 4 (200 mg/kg p.o.) of extract from the 1st to 10th day and a single dose of cisplatin (5 mg/kg, i.p.) on 11th day while group 5 received the same dose of cisplatin on day 1 and extract (200 mg/kg p.o.) from the 7th to 16th day.

RESULTS

Phytochemical screening of the extract revealed the presence of glycoside, alkaloids, tannins (phenolic compounds), flavonoids and amino acids. The half maximal inhibitory concentration (IC50) values of the extract were 31.75 ± 0.12 and 18.35 ± 0.48 µg/ml, respectively. The cisplatin-treated group 2 showed significant changes; renal functions, biochemical parameters and histopathology were significantly (**p < 0.01) recovered by 200 mg/kg curative and protective groups.

DISCUSSION AND CONCLUSION

These findings demonstrated that F. religiosa latex and constituents have excellent nephroprotective and curative activities and thus have great potential as a source for natural health products.

Protective effect of selenium on cisplatin induced nephrotoxicity: A double-blind controlled randomized clinical trial

BACKGROUND

Renal injury is common following cisplatin infusion. Some agents have been used to attenuate cisplatin nephrotoxicity. However, except hydration, none of them has been proved to be effective.

OBJECTIVE

In this study selenium as an antioxidant supplement was tested on cisplatin induced renal injury.

PATIENTS AND METHODS

122 cancerous patients (85 male and 37 female; age range of 14 to 82 years old) were enrolled to receive chemotherapy regimens consisting cisplatin. They were allocated into two groups using a random number list . Investigators, patients and analyzers all, were blinded in allocation by using sealed opaque envelopes. Intervention group received a single 400 mcg selenium tablet and patients in control group took a placebo tablet which was similar with selenium preparation in color, weight, shape and taste. Primary end points were an increase in plasma creatinine above 1.5 mg/dl in men and 1.4mg/dl in women, or increase of plasma creatinine more than 50% from baseline or urine flow rate less than 0.5 ml/kg/h. Creatinine level was measured initially and on the 5th day after cisplatin therapy.

RESULTS

There was no difference in cumulative dose of cisplatin between the groups (p=0.54). There were not evidences of acute renal failure (ARF) in cases. While, among placebo group, 7 patients had criteria of acute kidney injury. Conclusions :selenium could probably prevent cisplatin-induced acute kidney injury, when it is added to hydration therapy in cancerous patients.

Biochemical and histologic study of lethal cisplatin nephrotoxicity prevention by mirtazapine

BACKGROUND

Cisplatin is a platinum derivative frequently used in the chemotherapy of different solid tumors. This biochemical and histologic study investigated a possible protective effect of mirtazapine with regard to cisplatin-induced nephrotoxicity in the rat.

METHODS

The animals were divided into 4 groups: 15 mg/kg mirtazapine + 10 mg/kg cisplatin, 30 mg/kg mirtazapine + 10 mg/kg cisplatin, only 10 mg/kg cisplatin and negative control (healthy) group. During 14 days, the treatment and treated control group took drugs, while the healthy animals were given distilled water on the same schedule. All animals were sacrificed by high-dose anesthesia at the end of the 14 days of treatment; their kidneys were removed and subjected to histologic and biochemical study.

RESULTS

In both of the doses we used, mirtazapine decreased the levels of malondialdehyde, creatinine, blood urea nitrogen and myeloperoxidase activity when compared to cisplatin group. On the other hand, it increased total glutathione level in all doses. Slight histopathological findings were determined in mirtazapine groups when compared to cisplatin control group.

CONCLUSION

In the light of our results and literature knowledge, we can conclude that the protective effect of mirtazapine in cisplatin toxicity originates from its own antioxidant activity.

Carnosic acid attenuates renal injury in an experimental model of rat cisplatin-induced nephrotoxicity

Nephrotoxicity is one of the serious dose limiting side effects of cisplatin when used in the treatment of various malignant conditions. Accumulating evidence suggests that oxidative stress caused by free radicals and apoptosis of renal cells contributes to the pathogenesis of cisplatin-induced nephrotoxicity. Present study was aimed to explore the effect of carnosic acid, a potent antioxidant, against cisplatin induced oxidative stress and nephrotoxicity in rats. A single dose of cisplatin (7.5mg/kg) caused marked renal damage, characterized by a significant (P<0.05) increase in serum creatinine, blood urea nitrogen (BUN) and relative weight of kidney with higher kidney MDA (malondialdehyde), tROS (total reactive oxygen species), caspase 3, GSH (reduced glutathione) levels and lowered tissue nitrite, SOD (superoxide dismutase), CAT (catalase), GSH-Px (glutathione peroxidase), GR (glutathione reductase) and GST (glutathione S-transferase) levels compared to normal control. Carnosic acid treatment significantly (P<0.05) attenuated the increase in lipid peroxidation, caspase-3 and ROS generation and enhanced the levels of reduced glutathione, tissue nitrite level and activities of SOD, CAT, GSH-Px, GR and GST compared to cisplatin control. The present study demonstrates that carnosic acid has a protective effect on cisplatin induced experimental nephrotoxicity and is attributed to its potent antioxidant and antiapoptotic properties.

Renoprotective effect of Spirulina fusiformis on cisplatin-induced oxidative stress and renal dysfunction in rats

Cisplatin is an effective chemotherapeutic agent used in the treatment of a wide array of both pediatric and adult malignancies. Dose-dependent and cumulative nephrotoxicity is the major toxicity of this compound, sometimes requiring a reduction in dose or discontinuation of treatment. Recent evidences have implicated oxidative and nitrosative stress in cisplatin-induced nephrotoxicity. Spirulina fusiformis, blue-green algae, is claimed to be a potential antioxidant. The present study was designed to explore the renoprotective potential of Spirulina fusiformis against cisplatin-induced oxidative stress and renal dysfunction. Spirulina fusiformis (500,1000,1500 mg/kg(-1) p.o.) was administered 2 days before and until 3 days after cisplatin challenge (5 mg/kg(-1) i.p.). Renal injury was assessed by measuring serum creatinine, blood urea nitrogen, creatinine and urea clearance, and serum nitrite levels. Renal oxidative stress was determined by renal TBARS levels, reduced glutathione levels, and by enzymatic activity of superoxide dismutase and catalase. A single dose of cisplatin produced marked renal oxidative and nitrosative stress and significantly deranged renal functions. Chronic Spirulina fusiformis treatment significantly and dose-dependently restored renal functions, reduced lipid peroxidation, and enhanced reduced glutathione levels, superoxide dismutase, and catalase activities. The results of the present study clearly demonstrate the pivotal role of reactive oxygen species and their relation to renal dysfunction and point to the therapeutic potential of Spirulina fusiformis in cisplatin-induced nephrotoxicity.

The effects of ginkgo biloba extract on tissue adenosine deaminase, xanthine oxidase, myeloperoxidase, malondialdehyde, and nitric oxide in cisplatin-induced nephrotoxicity

This study was carried out to determine if Ginkgo Biloba Extract (GBE or Egb 761) exerts a beneficial effect against cisplatin-induced renal failure in rats. Sprague Dawley rats were divided into four groups. The first group (control) received orally 1 mL/kg/day of 0.9% saline by an oral carrier vehicle on days 1 to 10. The second group was injected with 7 mg/kg cisplatin intraperitoneally (i.p.) on the fourth day, once only. The third group (vit E+cisplatin) was administered 10 mg/kg/day i.p. vit E on 1 to 10 days with one dose of i.p. cisplatin (7 mg/kg) injection on the fourth day. The fourth group (GBE+cisplatin) was given GBE orally at 100 mg/mL/kg started on the first day up to the tenth day with one dose of cisplatin (7 mg/kg) injection on the fourth day. Cisplatin was found to lead a statistically significant increase in plasma BUN and creatinine levels, as well as urine micro total protein (MTP) levels, leading to acute renal failure (ARF) in rats. Renal xanthine oxidase (XO) activities increased in all groups (statistically significant in cisplatin + GBE-treated rats; P < 0.001). Adenosine deaminase (AD) activities were increased in cisplatin-treated rats, and decreased in cisplatin+GBE-treated (P < 0.041) and cisplatin+vit E-treated (P < 0.005) rats, compared to controls. Malondialdehyde (MDA), nitric oxide (NO) levels and myeloperoxidase (MPO) activities were increased in the kidney tissue of cisplatin-treated rats. Vit E improved plasma creatinine and urine MTP levels, together with tissue MDA, NO levels, and MPO activities. But GBE had no statistically significant effect on those parameters. These results indicate that increased XO, AD and MPO activities, as well as MDA and NO levels play a critical role in cisplatin nephrotoxicity. GBE has been shown to protect against cisplatin-induced nephrotoxicity.

Selenium for alleviating the side effects of chemotherapy, radiotherapy and surgery in cancer patients

BACKGROUND

Selenium supplements are frequently used by cancer patients. Selenium is an essential trace element and is involved in antioxidant protection and redox-regulation in humans. Several adverse effects of radiotherapy and chemotherapy in cancer patients as well as cellular processes that maintain chronic lymphoedema have been linked to oxidative cell damage in the human body. Selenium has recently been investigated as a remedy against chemotherapy and radiotherapy-associated side effects as well as its effects on lymphoedema.

OBJECTIVES

This review assessed the effects of supplementary selenium on adverse effects of conventional radiotherapy, chemotherapy, or surgery, in oncologic patients and on quality of life or performance status during and after oncologic treatment.

SEARCH STRATEGY

We searched the Cochrane Pain, Palliative & Supportive Care Trials Register, the Cochrane Database of Systematic Reviews (The Cochrane Library , Issue 2, 2004), Medline (1966 - Sep 2004), Embase (1980 - 2004 week 12), SIGLE (October 2004), Cancerlit (October 2004), Clinical Contents in Medicine CCMed (October 2004), the German Register of Cancer Studies (October 2004), the NCI Clinical Trials Register (October 2004), the International Standard Randomised Controlled Trial Number Register ISRCTN (October 2004) and the Meta-Register of Controlled Trials mRCT (October 2004), reference lists and the archive of our working group. We contacted manufacturers of selenium supplements and investigators.

SELECTION CRITERIA

Randomised-controlled trials of selenium mono-supplements in cancer patients undergoing tumour specific therapy such as chemotherapy, radiotherapy or surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently checked trials for eligibility, extracted data and assessed trial quality. We sought additional information from investigators when required.

MAIN RESULTS

Two trials have been included, a randomised controlled trial with 60 participants at the beginning of the study investigating secondary lymphoedema and an ongoing trial with preliminary results of 63 participants investigating radiotherapy induced diarrhoea as a secondary outcome. Both trials had drawbacks with regard to study quality and reporting. The trial on secondary lymphoedema reported a decreased number of recurrent erysipela infections in the selenium supplementation group compared to placebo. However, results must be interpreted with caution and cannot be generalised to other populations. The ongoing trial on radiotherapy associated diarrhoea preliminarily reported a lower incidence of diarrhoea in patients receiving selenium supplementation concomitant to pelvic radiation, however, no data were presented. Publication of final results must be awaited to discuss these findings in detail. No randomised controlled trials were found studying the effect of selenium supplementation on other therapy-associated toxicities or quality of life or performance status in cancer patients.

AUTHORS' CONCLUSIONS

There is insufficient evidence at present that selenium supplementation alleviates the side effects of tumour specific chemotherapy or radiotherapy treatments. Or, that it improves the after effects of surgery, or improves quality of life in cancer patients or reduces secondary lymphoedema. To date research findings do not provide a basis for any recommendation in favour or against selenium supplementation in cancer patients. Potential hazards of supplementing a trace mineral should be kept in mind.

Effect of Selenium on Cisplatin-Induced Nephrotoxicity in Rats

Cisplatin (CP), a commonly used antineoplastic drug, is nephrotoxic. CP-induced nephrotoxicity involves oxidative pathways. A deficiency of selenium (Se) reduces glutathione peroxidase (GPx) activity resulting in oxidative stress. We investigated how Se deficiency or oral Se administration influences CP-induced nephrotoxicity. Thirty male Wistar rats were fed a Se-deficient or control diet for 4 weeks. Then they were given intraperitoneal (i.p.) CP alone, i.p. saline alone, or Se by gavage 24 and 1 h prior to i.p. CP. Blood and urine samples were collected and the kidneys were removed 5 days after CP treatment. Urinalysis, renal function, GPx activity, and expression of cellular GPx mRNA were measured. Histology was evaluated by light microscopy with immunohistochemistry for 4-hydroxy-2-nonenal (HNE), vimentin, and heme oxygenase (HO)-1. CP induced renal tubular damage with increased expression of vimentin, HO-1 and HNE staining, which represents lipid peroxidation. Se deficiency exacerbated CP-induced nephrotoxicity as shown by deterioration of the above parameters and depressed GPx activity and expression of GPx mRNA. Se treatment ameliorated CP-induced nephrotoxicity, but did not significantly improve renal function. These findings suggest that Se deficiency increases oxidative stress and enhances CP-induced nephrotoxicity, whereas oral Se treatment partially protects against the nephrotoxicity in rats.

6-Gingerol prevents cisplatin-induced acute renal failure in rats

BACKGROUND

Nephrotoxicity is a major complication and a dose limiting factor for cisplatin therapy. Recent evidence suggests that enhanced oxidative stress caused by oxygen-centered free radicals may contribute to the pathogenesis of cisplatin-induced acute renal failure. 6-Gingerol is claimed to be a potent antioxidant. The present study was performed to explore the renoprotective potential of 6-gingerol on cisplatin-induced oxidative stress and renal dysfunction.

METHODS

6-Gingerol in dosages of 12.5, 25, 50 mg/kg was administered 2 days before and 3 days after cisplatin administration. Renal injury was assessed by measuring serum creatinine, blood urea nitrogen, creatinine, urea clearance and serum nitrite levels. Renal oxidative stress was assessed by determining renal malondialdehyde levels, reduced glutathione levels and enzymatic activities of superoxide dismutase and catalase.

RESULTS

A single dose of cisplatin resulted in marked renal oxidative and nitrosative stress and significantly deranged renal functions. 6-Gingerol treatment significantly and dose-dependently restored renal functions, reduced lipid peroxidation and enhanced the levels of reduced glutathione and activities of superoxide dismutase and catalase.

CONCLUSIONS

The present study demonstrates the renoprotective potential of 6-gingerol against cisplatin-induced oxidative stress and renal dysfunction in rats. Hence, 6-gingerol has a potential to be used as therapeutic adjuvant in cisplatin nephrotoxicity.

Effect of oral administration of Arabic gum on cisplatin-induced nephrotoxicity in rats

It has been recently postulated from our laboratory that Arabic gum (AG) offers a protective effect in the kidney of rats against nephrotoxicity induced by gentamicin via inhibiting lipid peroxidation. It has also recently shown a powerful antioxidant effect through scavenging superoxide anions. In this study we utilized a rat model of cisplatin (CP)-induced nephrotoxicity to determine its peak time following (1, 2, 5, and 7 days) of a single CP (7.5 mg/kg, i.p.) injection. Also, a possible protective effect of cotreatment with AG (7.5 g/kg/day p.o.) on CP-induced nephrotoxicity was investigated. Biochemical as well as histological assessments were carried out. CP-induced nephrotoxicity was manifested by significant elevations of the functional parameters blood urea, serum creatinine, and kidney/body weight ratio. Maximum toxic effects of CP were observed 5 days after its injection, while it started after day 1 in the biochemical parameters, such as glutathione depletion in the kidney tissue with concomitant increases in lipid peroxides and platinum content. Additionally, severe necrosis and desquamation of tubular epithelial cells in renal cortex as well as interstitial nephritis were observed after 5 days in CP-treated animals. Five days after AG cotreatment with CP did not protect the kidney from the damaging effects of CP. However, it significantly reduced CP-induced lipid peroxidation. These findings suggest that lipid peroxidation is not the main cause of CP-induced nephrotoxicity but it is rather more dependent on other factors such as platinum disposition in renal interstitial tubules.

Antioxidantes da dieta como inibidores da nefrotoxicidade induzida pelo antitumoral cisplatina

A cisplatina é uma droga antineoplásica altamente efetiva contra vários tipos de cânceres humanos, tais como tumores do testículo e ovário, câncer da cabeça e pescoço e câncer do pulmão. Entretanto, a nefrotoxicidade é um dos principais efeitos colaterais da terapia com a cisplatina. A gravidade da nefrotoxicidade induzida pela cisplatina está relacionada com a concentração de platina nos rins. As evidências mostram que a nefrotoxicidade induzida pela cisplatina é atribuída ao dano oxidativo resultante da geração de radicais livres, e que a administração de antioxidantes é eficiente na inibição destes efeitos colaterais. Uma abordagem alternativa para proteger os roedores dos efeitos colaterais da cisplatina é o uso de conhecidos antioxidantes da dieta. Alguns estudos têm sido realizados para diminuir a peroxidação lipídica e os efeitos citotóxicos induzidos pela cisplatina, com o emprego de antioxidantes da dieta, tais como, selenito de sódio, vitaminas C e E, curcumina e o carotenóide bixina. Nós sugerimos que aqueles antioxidantes da dieta têm efeito nefroprotetor, e que os mecanismos antioxidantes destes compostos deveriam ser explorados durante a quimioterapia com a cisplatina.

Antioxidant action of bixin against cisplatin-induced chromosome aberrations and lipid peroxidation in rats

Cisplatin is one of the most active cytotoxic agents in the treatment of cancer, but has serious side effects, inducing nephrotoxicity and chromosome aberrations. In this study we evaluated the role of the carotenoid bixin on cisplatin-induced oxidative stress in Wistar rats through three markers of oxidative damage: chromosome aberrations, glutathione depletion and lipid peroxidation. The animals were divided into six treatment groups with six rats in each (n= 6). The dose of cisplatin (5.0 mg kg(-1)body wt.) was injected i.p. and bixin (2.5 or 5.0 mg kg(-1)body wt.) was given by gavage at 48, 24 h and 10 min before the cisplatin injection. The treatment with the highest dose of bixin resulted in a statistically significant reduction, by about 33%, in cisplatin-induced abnormal metaphases (P< 0.05). A single dose of cisplatin enhanced the formation of lipid peroxides in 29% and resulted in a 29% depletion in renal glutathione 24 h after cisplatin administration (P< 0.05). The pretreatment with bixin reduced the total number of chromosome aberrations, inhibited the increase in lipid peroxidation, and inhibited renal glutathione depletion induced by cisplatin. Since the pretreatment with bixin alone was safe, under the present experimental conditions, the results suggest that bixin may have future clinical application after further studies.