Central European Journal of Medicine
* E-mail: karadenizali@gmail.com
Protective effect of L-carnitine against cisplatin-induced liver and kidney oxidant injury in rats
Received 20 November 2008; Accepted 10 January 2009 Abstract: The present study was designed to investigate the protective effects of L-carnitine (LC) on changes in the levels of lipid peroxidation and endogenous antioxidants induced by cisplatin (cis-diamminedichloroplatinum II, CDDP) in the liver and kidney tissues of rats.
Twenty-four Sprague Dawley rats were equally divided into four groups of six rats each: control, cisplatin, L-carnitine, and L-carnitine plus cisplatin. The degree of protection produced by L-carnitine was evaluated by determining the level of malondialdehyde (MDA).
The activity of glutathione (GSH), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST), and superoxide dismutase (SOD) were estimated from liver and kidney homogenates, and the liver and kidney were histologically examined as well. L-carnitine elicited significant liver and kidney protective activity by decreasing the level of lipid peroxidation (MDA) and elevating the activity of GSH, GSH- Px, GST, and SOD. Furthermore, these biochemical observations were supported by histological findings. In conclusion, the present study indicates a significant role for reactive oxygen species (ROS) and their relation to liver and kidney dysfunction, and points to the therapeutic potential of LC in CDDP-induced liver and kidney toxicity.
© Versita Warsaw and Springer-Verlag Berlin Heidelberg.
Keywords: L-carnitine • Cisplatin • Liver • Kidney • Oxidative damage
1 Department of Internal Medicine, Faculty of Medicine, University of Atatürk, 25700 Erzurum, Turkey
2 Department of Physiology, Faculty of Veterinary Medicine, University of Atatürk, 25700 Erzurum, Turkey
3 Department of Biochemistry, Faculty of Medicine, University of Atatürk, 25700 Erzurum, Turkey
4 Department of Histology and Embryology, Faculty of Medicine, University of Atatürk, 25700 Erzurum, Turkey
Kerim Cayir1, Ali Karadeniz2*, Abdulkadir Yildirim3, Yildiray Kalkan4, Akar Karakoc3, Mustafa Keles1, Salim Basol Tekin1
Research Article
1. Introduction
Palliative care is treatment for incurable cancer patients.
It seeks to decrease their cancer-related symptoms, advance their quality of life, and lengthen their life spans. Many studies have indicated the palliative effect of chemotherapy for incurable cancers species involving the liver, pancreas, and lungs. Conversely, treatment with anticancer drugs can have harmful effects, and the toxicities may lead to a worsened quality of life and shortened survival [1,2]. Cisplatin (cis- diamminedichloroplatinum II, CDDP) is one of the major
therapeutic compounds, widely used for the treatment of various cancer species such as ovarian, lung, and testicular cancers [3,4]. However, its clinical usage in high doses is restricted in practice because of its strong side effects in the liver, the kidneys, and other organs [5,6]. CDDP causes the generation of reactive oxygen species (ROS), depletion of GSH levels, and inhibition of antioxidant enzyme activity in these tissues. Additionally, many studies show that CDDP induces oxidative stress, lipid peroxidation, and DNA damage [7,8]. Therefore, prevention of the side effects from CDDP is one of the main problems in cancer chemotherapy.
CDDP acts on cancer cells by releasing free radicals, which lead to the dysfunction of both the liver and the kidneys. CDDP-induced hepatotoxicity has rarely been characterized, and it has been little studied. However, it is known that CDDP is metabolized in the human liver to a significant degree, and high doses of the drug induce hepatotoxicity [9,10]. Nath and Norby [11] reported that CDDP decreased kidney glutathione content and increased lipid peroxidation, that CDDP interacted with DNA in a cell-free system and generated superoxide anions, and that oxidant-scavenging enzymes and assorted antioxidants protected against CDDP-induced renal injury. Thus, the administration of antioxidants such as ebselen [12], vitamin C [6], and selenium [7]
before treatment with CDDP has been used to protect against ovary, kidney, and liver toxicities in human and experimental animals.
L-carnitine (LC) is a natural nutrient that is essential for the β-oxidation of fatty acids in mitochondria to generate ATP. It is synthesized endogenously from the essential amino acids lysine and methionine. In fact, carnitine effectively inhibits mitochondrial damage induced by oxidative stress, as well as mitochondria- dependent apoptosis in various types of cells [13,14].
The effects of LC on the metabolism of tissues in organs such as the heart [15], brain [16], and liver [13] have been studied widely. Current reports suggest that LC may play a significant role in balancing antioxidative systems and has an antiperoxidative effect on some tissues [17,18]. The aim of this study was to investigate possible protective effects of exogenous LC supplementation on CDDP-induced oxidative organ injuries, and its effects on the levels of antioxidant enzymes and lipid peroxidation, as well as histological changes.
2. Material and Methods
2.1. Animals and treatments
Adult female Sprague Dawley rats, 180 ± 20 g, 6–8 weeks old, were provided by the Atatürk University’s Experimental Research Centre, Erzurum, Turkey. The animals were housed in metal cages under standard room temperature (22°C) and a 12-hour light/dark cycle with free access to commercial standard rat chow (Bayramoğlu, Erzurum, Turkey) and water.
All experiments in this study were approved by the Committee on Animal Research at Atatürk University, Erzurum.
The animals were divided into 4 groups, each with 6 rats, and were named according to their experimental treatment: the control (named Group C), the group
receiving L-carnitine (Group LC), the group receiving cisplatin (Group CDDP), and the group receiving both L-carnitine and cisplatin (Group LC + CDDP). Group C received single-dose intraperitoneal (i.p.) injections of 1 ml isotonic saline for 10 consecutive days. Group LC received single-dose injections of L-carnitine (500 mg kg−1 i.p.; Santa Farma, İstanbul, Turkey) for 10 consecutive days. Group CDDP received a single-dose injection of CDDP (7 mg kg−1 body weight i.p. and 0.5 mg ml-1; Ebewe and Liba, respectively, Istanbul, Turkey) all at once. Group LC + CDDP received single doses of L-carnitine (500 mg kg−1 i.p.) for 10 consecutive days following a single-dose i.p. injection of CDDP (7 mg kg−1). The doses of CDDP and L-carnitine used in this study were selected in accordance with Al-Majed [13].
2.2. Sample collection and biochemical assays
All animals were previously anaesthetized with an i.p.
injection of 60 mg sodium pentobarbitone per kg of body weight, and then sacrificed by cervical dislocation 24 hours after the final saline, LC, and CDDP injections.
The livers and kidneys of the rats were removed, washed with physiological saline solution, and stored at –20°C until analysis.
All tissues were maintained at +4°C throughout preparation. A portion of the liver and kidney tissues (1:9, w/v) for all assays were homogenized in a 0.9% NaCl solution with an OMNI TH International homogenizer (Warrenton, VA, USA). Tissue homogenates were centrifuged for 15 minutes at 15,000 g, and then the clear upper supernatants were removed for analyses.
2.2.1. Determination of MDA
MDA levels in tissues were determined spectrophotometrically according to the method described by Ohkawa [19]. A mixture of 8.1% sodium dodecyl sulphate, 20% acetic acid, and 0.9%
thiobarbituric acid was added to 0.2 ml of each sample, and then distilled water was added to the mixture to bring the total volume up to 4 ml. This mixture was incubated at 95°C for 1 hour. After incubation, the tubes were left to cool under cold water and 1 ml distilled water plus 5 ml n-butanol/pyridine (15:1, v/v) were added, followed by mixing. The samples were centrifuged at 4000 x g for 10 minutes. The supernatants were removed, and absorbances were measured with respect to a blank at 532 nm. 1,1,3,3-Tetraethoxypropane was used as the standard. Lipid peroxide levels were expressed as nmol/L MDA.
2.2.2. Determination of GSH
GSH levels in tissues were assessed according to the methods described by Tietze [20] and Anderson [21]. Briefly, 100 µl of each sample was placed into a 3 ml cuvette, and then 750 µl of 10 mM 5-5’-dithiobis- 2-nitrobenzoic acid (DTNB) solution (100 mM KH2PO4 plus 5 mM Na2EDTA, pH 7.5 and GSH-RD, 625 U/l) was added and the samples were incubated for 3 minutes at room temperature. Then 150 µl of 1.47 mM β-NADPH was added, mixed rapidly by inversion, and the rate of 5-thio-2-nitrobenzoic acid formation (proportional to the sum of reduced and oxidized glutathione) was measured spectrophotometrically for 2 minutes at 412 nm. The reference cuvette contained equal concentrations of DTNB and NADPH but no sample, and values were presented as µmol per gram protein.
2.2.3. Determination of GSH-Px activity
GSH-Px activity in tissues was measured by the method of Paglia and Valentine [22]. Briefly, 50 µl of sample was combined with 100 µl of 8 mM NADPH, 100 µl of 150 mM reduced glutathione, 20 µl of glutathione reductase (30 units/ml), 20 µl of 0.12 M sodium azide solution, and 2.65 ml of 50 mM potassium phosphate buffer (pH 7.0, 5 mM EDTA). The tubes were incubated for 30 min at 37°C. The reaction was initiated with the addition of 100 µl of 2 mM H2O2 solution and mixed rapidly by inversion.
The conversion of NADPH to NADP was measured spectrophotometrically for 5 minutes at 340 nm. The enzyme activity was expressed as units per g protein using an extinction coefficient for NADPH at 340 nm of 6.22 x 10-6.
2.2.4. Determination of GST activity
Glutathione-S-transferase (GST) activity was assayed by using the electrophilic substrate 1-chloro-2,4- dinitrobenzene (CDNB) according to the procedure described by Habig et al. [23]. GST was estimated in 1 mL of incubation mixture containing 905 μL of 0.1 M phosphate buffer (pH 6.5), 20 μL of 20 mM CDNB reagent, 25 μL of 200 mM of reduced GSH, and 25 μL of triton × 100 (0.66%), and pre-incubated at 37°C for 5 minutes. The reaction was started by adding 25 μL of the sample. Enzyme activity was determined by continuously monitoring the change in absorbance at 340 nm with spectrophotometery for 3 minutes. The O.D. change/min was calculated, and GST activity was estimated by using the molar extinction coefficient [9.6 mM−1 cm−1] of GST.
2.2.5. Determination of SOD activity
Cu, Zn-SOD activity in tissues was detected by the method of Sun et al. [24]. 2.45 ml of assay reagent [0.3
mM xanthine, 0.6 mM Na2EDTA, 0.15 mM NBT, 0.4 M Na2CO3, and 1 g/L bovine serum albumin (BSA)] was combined with 100 µl of tissue homogenate. Xanthine oxidase (50 µl, 167 U/L) was added to initiate the reaction, and the reduction of NBT by superoxide anion radicals, which are produced by the xanthine-xanthine oxidase system, was determined by measuring the absorbance at 560 nm. Cu, Zn-SOD activity was expressed in units of SOD per mg protein, where 1 U is defined as that amount of enzyme causing half-maximal inhibition of NBT reduction.
2.3. Histological evaluation
For light microscopy, the livers and kidneys were fixed in 10% formalin, and embedded in paraffin. The paraffin blocks were cut 5 μm thick and stained with Mallory’s triple stain modified by Crossman. Thereafter, degenerative changes were examined in 10 randomly selected areas of approximately 0.75 mm2 at ×40 objective with an ocular micrometer. The microscopic scoring of sections was carried out by a histopathology laboratory technician and histologist. Evaluations of the liver were of hepatocellular degeneration, cell swelling, mononuclear cell infiltration, vascular congestion, and sinusoidal dilatation, according to Mohan et al. [25].
Kidney evaluations were of tubular necrosis, dilatation of Bowman’s capsule, medullar congestion, and the dilatation of collective tubules for kidney [25]. This scale has composed to A = weak in ≤ 25% of tissue; B = mild in ≥ 25 – ≤ 50% of tissue; C = moderate in ≤ 75% of tissue; and D = very strong in ≥ 75–100% of tissue. The average degeneration intensity was calculated as [(A × 1) + (B × 2) + (C × 3) + (D × 4)]/(A + B + C + D) and reported as follows: + = 0.00–1.00; ++ = 1.01–2.00; +++
= 2.01–3.00; and ++++ = 3.01–4.00. The scores were derived semi-quantitatively using light microscopy on the preparations from each animal, and were reported as follows: none = –, mild = +, moderate = ++, severe = +++, and very strong = ++++.
2.4. Statistical analysis
For statistical analysis, differences between the groups were tested by the analysis of variance (ANOVA) followed by Duncan’s post-hoc test [26] using SPSS 11.0 for Windows XP (SPSS Inc., Chicago, IL). A value P < 0.05 was considered significant. All data were expressed as mean averages, ± S.E.M.
3. Results
3.1. Biochemical results
The changes in MDA levels and GSH, GSH-Px, GST, and SOD activity in the livers and kidneys are shown in Table 1. When compared to the control groups, the MDA levels in the livers and kidneys were significantly (p < 0.05) higher in groups administered with CDDP.
On the other hand, this increase was attenuated by pre-treatment with L-carnitine. The CDDP-treated rats showed significantly (p < 0.05) reduced GSH, GSH- Px, GST and SOD activity in the liver and renal tissues when compared with the control groups. Pre-treatment of rats with L-carnitine alleviated the CDDP-induced decreases in GSH, GSH-Px, GST and SOD activity in the liver and renal tissues (Table 1). On the other hand, the group administered only L-carnitine did not show any statistically significant difference, in comparison to the control group, for all parameters.
3.2. Histological results
The histological changes were evaluated and are presented in Table 2. The livers and kidneys of the control animals and the L-Carnitine-only groups showed normal histology (Figures 1 and 2). In the liver sections of the cisplatin group, sinusoidal dilatation and congestion, hepatocellular degeneration, and inflammatory infiltrations were observed (Figure 1). In addition, in the kidney sections, microscopic changes were observed,
GroupsMDA (nmol/ g protein)GSH (µmol/ g protein)GSHPx (U/ g protein)GST (µmol/ g protein)SOD (U/ g protein) LiverKidneyLiverKidneyLiverKidneyLiverKidneyLiverKidney C42.5 ± 11.20a15.80 ± 1.15a125.55 ± 10.50a41.70 ± 0.05a100.10 ± 8.45a92.35 ± 8.25a75.55 ± 7.20a45.30 ± 12.20a680.20 ± 45.20a648.80 ± 24.50a CDDP61.2 ± 8.30b29.40 ± 1.40b98.85 ± 10.20b21.25 ± 0.20b80.25 ± 9.40b38.20 ± 10.20b52.48 ± 8.24b18.30 ± 9.25b498.30 ± 45.70b457.60 ± 41.40b LC48.8 ± 8.30a16.15 ± 0.90a135.20 ± 9.48a40.59 ± 0.15a105.50 ± 7.60a85.80 ± 11.30a88.40 ± 8.50a40.50 ± 14.50a745.80 ± 47.50a605.30 ± 33.80a LC + CDDP52.2 ± 10.20c20.25 ± 0.75c120.60 ± 8.35c41.30 ± 0.07c88.60 ± 6.30c62.80 ± 14.25c67.50 ± 8.45c30.10 ± 11.65c565.20 ± 26.20c501.20 ± 23.40c Different superscripts a,b,c in the same column indicate significant differences between groups (n=6). P <0.05. means ± S.E.M, C: Control, CDDP:Cisplatin, LC: L-carnitine
Table 1. The levels of malondialdehyde (MDA) and acitivities of reduced glutathione (GSH), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) and superoxide dismutase (SOD) in liver and kidney tissues of all groups.
Figure 1. a: Control group, b: LC group, c-d: CDDP group, e-f:
LC + CDDP group, central vein (CV), mononuclear cell infiltration in portal areas (arrow), sinusoidal congestion and dilatations (arrow heads). Triple stain of liver, X 625.
with degeneration and desquamation in the tubular epithelium around the glomeruli, severe glomerular congestion, dilatation in Bowman’s space, enlargement of the lumen of collective tubules, and flattening of the epithelium of collective tubules (Figure 2).
In the cisplatin-plus-L-Carnitine group, marked decreases in cytoplasmic changes of the hepatocytes, sinusoidal dilatations around the central vein, and inflammatory cell infiltration in the portal area were noticed when compared to the cisplatin group (Figure 1).
Furthermore, in the kidney sections, L-Carnitine considerably decreased the tubular degeneration and dilatation in Bowman’s space and collective tubules, and caused ameliorative changes (Figure 2).
4. Discussion
Cisplatin is one of the most active cytotoxic agents in the treatment of cancer. Liver and kidney toxicity are major complications, which is a dose-limiting factor for cisplatin therapy [10]. Although the exact mechanisms of CDDP- induced nephrotoxicity are still not fully understood, lipid peroxidation and free radical generation in the tubular cells have been suggested as being responsible for the nephrotoxicity [7,27]. In the present study, it was shown that treatment with only CDDP caused nephrotoxicity in rats, as evidenced by the high biochemical parameters such as high lipid peroxidation and low antioxidant activity, and by histological changes as well. Many studies have reported similar structural changes in the kidney [6,28,29]. In the same way, CDDP caused severe damage in the liver, such as degenerative hepatocytes and moderate enlargement of sinusoids, which was observed by microscopic examination [30,31].
Previous studies have reported the role of reactive oxygen species (ROS) in mediating the kidney and liver toxicity of xenobiotics [32,33]. CDDP increases the intracellular production of oxygen and nitrogen species in the kidney and liver by increasing the activity of cytochrome P450 enzymes, NADPH oxidase, xanthine oxidase, and adenosine deaminase [34]. In the present study, the level of liver and kidney MDA in the CDDP- treated group was significantly higher compared with their levels in the controls. Increased MDA levels indicated that lipid peroxidation, mediated by ROS, was an important contributing factor in the development of CDDP-mediated tissue damage. However, pretreatment with L-carnitine significantly prevented CDDP-induced lipid peroxidation in the liver and kidney tissues, implicating an antioxidant effect from this molecule. This was probably due to less damage having occurred from oxygen-free radicals. In previous studies, CDDP has been found to have an antiperoxidative effect on several tissues, such as the liver, kidney, and lens [35-37].
Groups n Degeneration intensity Average of degeneration value
Liver Kidney Liver Kidney
C 6 - - 0 0
CDDP 6 ++++ +++ 3.27 2.53
LC 6 + - 0.23 0
LC + CDDP 6 ++ ++ 1.80 1.36
Light microscopy (approximately, in each area 0.75 mm2 X 40 objective) was used to evaluate liver and kidney damages. Average degeneration intensity was calculated as [(A x 1) + (B x 2) + (C x 3) + (D x 4)] / (A + B + C + D) and reported as follows: + = 0.00–1.00; ++ = 1.01–2.00;
+++ = 2.01–3.00; ++++ = 3.01–4.00. A = weak, ≤ 25% of tissue; B = mild in ≥ 25 – ≤ 50% of tissue; C = moderate in ≤ 75% of tissue, D = very strong in ≥ 75–100% of tissue.
C: Control, CDDP:Cisplatin, LC: L-carnitine
Table 2. Semiquantitaivy analysis of histopathological lesions in liver ad kidney of experimental groups.
Figure 2. a-b: Control group, pyramidal epithelium in collective tubules (arrow heads); c-d: CDDP group, degeneration and desquamation in tubules (arrow), capillary congestion in medulla (bold arrows), and flattening in the epithelium and dilatations in collective tubules (arrow heads); e-f: LC + CDDP group, amelioration in the epithelium of collective tubules (arrow heads). Triple stain in kidney, X 450.
GSH is the most important molecule for maintaining cell integrity and participation in cell metabolism [38].
The role of GSH, which are non-protein thiols in the cells, in the formation of conjugates with electrophilic drug metabolites (most often formed by cytochrome P450-linked monooxygenase) is well established [39].
The significant reduction in GSH levels promoted by CDDP represents an alteration in the cellular redox state, suggesting that the cells could be more sensitive to ROS. This leads to a reduction in effectiveness of the antioxidant enzyme defense system [40]. In this study, GSH levels in the liver and kidney tissues of rats treated with CDDP were lower than the control group’s.
On the other hand, an increase in GSH levels in the liver and kidney tissues indicated that pre-treatment with L-carnitine caused the increase as a response to oxidative stress. The effects of L-carnitine on cellular GSH may be due directly to antioxidant effects or to the enhanced biosynthesis of GSH.
The reduced kidney and liver GST, GSH-Px, and SOD activity in animals treated with CDDP alone was compared with the control group’s levels of activity.
These observations indicated that the mechanism of kidney and liver toxicity induced by CDDP in animals is partially related to the depletion of the kidney and liver antioxidant systems. Treatment with L-carnitine before the CDDP challenge could significantly prevent the depletion of the kidney and liver antioxidant systems.
Similar results have been reported by Aleisa et al. [14], Al-Majed et al. [15], and Arafa HM [41] for kidney and liver tissues in which cisplatin and carboplatin injections caused low GSH, GSH-Px, SOD, and nitric oxide levels.
Furthermore, in this study, it was observed that levels of GSH-Px and SOD for CDDP in the L-carnitine-treated groups were higher than in the CDDP group. These results suggested that L-carnitine has a supporting effect on the antioxidant system because of increases in GSH- Px and SOD levels. Recently, it has been demonstrated that L-carnitine prevents tilmicosine- and CDDP-induced cardiotoxicity [42] and neurotoxicity [43].
These results correlated well with the histological results from the livers and kidneys, which revealed hepatocellular degeneration and inflammatory cell infiltration in the portal area, and particularly tubular necrosis in the renal cortex. The histological results are presented in Table 2. The livers and kidneys of the control and L-carnitine groups showed normal histological features. However, rats given CDDP had a moderately severe glomerular congestion and degeneration, dilatation in Bowman’s space and in the collective tubules in the kidney sections. They had hepatocellular degeneration, and inflammatory infiltrations in the liver sections. On the other hand, the tubules and liver cells from rats in the CDDP + L-carnitine group were nearly normal in histological architecture, except for a minor desquamation of the kidney and liver epithelial cells.
Similar findings were also reported by Yuce et al. [44]
and Tarladacalisir et al. [6], demonstrating the structural changes in the kidney and liver tissues of CDDP-treated animals and its turn back by different agents.
In summary, we have shown that experimental CDDP administration caused an increase in lipid peroxidation in rats. We therefore think that oxidative stress may result from the CDDP-induced pathophysiology. Further studies should address whether pre-treatment with L-carnitine has the potential to improve cisplatin-induced liver and kidney damage. The L-carnitine supplementation may play a protective role or decrease the side effects of CDDP-induced liver and kidney toxicity from cancer medicines.
Acknowledgements
The authors are indebted to the anonymous reviewers for valuable suggestions on the manuscript. The authors would like to express their gratitude to the Center of Experimental Research and Practice at the Atatürk University for providing the animals, and for the approval of this study under the required ethical rules.
[1] Cella D.F., Measuring quality of life in palliative care.
Semin. Oncol., 1995, 22 (2 Suppl 3), 73–81
[2] World Health Organization. Cancer pain relief and palliative care: Report of a WHO expert committee (Technical Report Series 804. Geneva, Switzerland:
WHO, 1990.
[3] Turk G., Atessahin A., Sonmez M., Ceribasi A.O., Yuce A., Improvement of cisplatin-induced injuries to sperm quality, the oxidant-antioxidant system, and the histologic structure of the rat testis by ellagic
acid. Fertil. Steril., 2008, 89, 1474–1481
[4] Gottfried M., Ramlau R., Krzakowski M., Ziolo G., Olechnowicz H., Koubkova L. et al., Cisplatin-based three drugs combination (NIP) as induction and adjuvant treatment in locally advanced non-small cell lung cancer: final results. J. Thorac. Oncol., 2008, 3, 152–157
[5] Liao Y., Lu X., Lu C., Li G., Jin Y., Tang H., Selection of agents for prevention of cisplatin-induced hepatotoxicity. Pharmacol. Res., 2008, 57, 125–131 References
[6] Tarladacalisir Y.T., Kanter M. , Uygun, M., Protective effects of vitamin C on cisplatin-induced renal damage: a light and electron microscopic study.
Ren. Fail., 2008, 30, 1–8
[7] Naziroglu M., Karaoglu A., Aksoy A.O., Selenium and high dose vitamin E administration protects cisplatin- induced oxidative damage to renal, liver and lens tissues in rats. Toxicology, 2004, 195, 221-–230 [8] Koc A., Duru M., Ciralik H., Akcan R., Sogut S.,
Protective agent, erdosteine, against cisplatin- induced hepatic oxidant injury in rats. Mol. Cell Biochem., 2005, 278, 79–84
[9] Iseri S., Ercan F., Gedik N., Yuksel M., Alican I., Simvastatin attenuates cisplatin-induced kidney and liver damage in rats. Toxicology, 2007, 230, 256–264
[10] Tikoo K., Tamta A., Ali I.Y., Gupta J., Gaikwad A.B., Tannic acid prevents azidothymidine (AZT) induced hepatotoxicity and genotoxicityalong with change in expression of PARG and histone H3 acetylation.
Toxicol. Lett., 2008, 177, 90–96
[11] Nath K.A., Norby S.M., Reactive oxygen species and acute renal failure. Am. J. Med., 2000, 109, 665–678.
[12] Lynch E.D., Gu R., Pierce C., Kil J., Combined oral delivery of ebselen and allopurinol reduces multiple cisplatin toxicities in rat breast and ovarian cancer models while enhancing anti-tumoractivity.
Anticancer Drugs, 2005, 16, 569–579
[13] Al-Majed A.A., Carnitine deficiency provokes cisplatin-induced hepatotoxicity in rats. Basic Clin.
Pharmacol. Toxicol., 2007, 100, 145–150
[14] Aleisa A.M., Al-Majed A.A., Al-Yahya A.A., Al-Rejaie S.S., Bakheet S.A., Al- Shabanah O.A. et al., Reversal of cisplatin-induced carnitine deficiency and energy starvation by propionyl-L-carnitine in rat kidney tissues. Clin. Exp. Pharmacol. Physiol., 2007, 34, 1252–1259
[15] Al-Majed A.A., Sayed-Ahmed M.M., Al-Yahya A.A., Aleisa A.M., Al-Rejaie S.S., Al-Shabanah O.A., Propionyl-L-carnitine prevents the progression of cisplatin-induced cardiomyopathy in a carnitine- depleted rat model. Pharmacol. Res., 2006, 53, 278–286
[16] Sezen O., Ertekin M.V., Demircan B., Karslıoglu I., Erdogan F., Kocer I., et al., Vitamin E and L-carnitine, separately or in combination, in the prevention of radiation-induced brain and retinal damages. Neurosurg. Rev., 2008, 31, 205–213 [17] Aydogdu N., Atmaca G., Yalcin O., Taskiran R.,
Tastekin E., Kaymak K., Protective effects of L-carnitine on myoglobinuric acute renal failure in rats. Clin. Exp. Pharmacol. Physiol., 2006, 33, 119–124.
[18] Cetinkaya A., Bulbuloglu E., Kantarceken B., Ciralik H., Kurutas E.B., Buyukbese M.A. et al., Effects of L-carnitine on oxidant/antioxidant status in acetic acid-induced colitis. Dig. Dis. Sci., 2006, 51, 488–494
[19] Ohkawa H., Ohishi N., Yagi K., Assay for lipid peroxidase in animal tissues by thiobarbituric acid reaction. Anal. Biochem., 1979, 95, 351–358 [20] Tietze F., Enzymic method for quantitative
determination of nanogram amounts of total and oxidized glutathione, applications to mammalian blood and other tissues. Anal. Biochem., 1969, 27, 502–522
[21] Anderson M.E., Determination of glutathione and glutathione disulfide in biological samples.
Methods Enzymol., 1985, 113, 548–555
[22] Paglia D.E., Valentine W.N., Studies on the quantitative and qualitative characterisation of erythrocyte glutathione peroxidase. J. Lab. Clin.
Med., 1967, 70, 158–69
[23] Habig W.H., Pabst M.J., Jakoby W.B., Glutathione S-transferases. The first enzymatic step in mercapturic acid formation. J. Biol. Chem., 1974, 249, 7130–7139
[24] Sun Y., Oberley L.W., Li Y., A simple method for clinical assay of superoxide dismutase. Clin.
Chem., 1988, 34, 497–500
[25] Mohan I.K., Khan M., Shobha J.C., Naidu M.U., Prayag A., Kuppusamy P. et al., Protection against cisplatin-induced nephrotoxicity by Spirulina in rats. Cancer Chemother. Pharmacol., 2006, 586, 802–808
[26] Sumbuloglu K., Sumbuloglu V., Biyoistatistik. 5 th ed. Özdemir Basım Yayım ve Dağıtım Ltd. Şti., Ankara, 1996 [in Turkish]
[27] Yilmaz H.R., Sogut S., Ozyurt B., Ozugurlu F., Sahin S., Isik B., et al., The activities of liver adenosine deaminase, xanthine oxidase, catalase, superoxide dismutase enzymes and the levels of malondialdehyde and nitric oxide after cisplatin toxicity in rats: Protective effect of caffeic acid phenethyl ester. Toxicol. Indust. Health., 2005, 21, 67–73
[28] Ajith T.A., Nivitha V., Usha S., Zingiber officinale Roscoe alone and in combination with alpha- tocopherol protect the kidney against cisplatin- induced acute renal failure. Food Chem. Toxicol., 2007, 45, 921–927
[29] Atessahin A., Yilmaz S., Karahan I., Ceribasi A.O., Karaoglu A., Effects of lycopene against cisplatin- induced nephrotoxicity and oxidative stres in rats.
Toxicology, 2005, 212, 116–123
[30] Amaral C., Francescato H., Coimbra T., Costa R.,
Darin J., Antunes L. et al., Resveratrol attenuates cisplatin-induced nephrotoxicity in rats. Arch.
Toxicol., 2008, 82, 363–370
[31] Miyamoto Y., Shimada K., Sakaguchi Y., Miyamoto M., Cisplatin (CDDP)-induced acute toxicity in an experimental model of hepatic fibrosis. J. Toxicol.
Sci., 2007, 32, 311–319
[32] Sohn J.H., Han K.L., Kim J.H., Rukayadi Y., Hwang J.K., Protective Effects of macelignan on cisplatin- induced hepatotoxicity is associated with JNK activation. Biol. Pharm. Bull., 2008, 31, 273–277 [33] Tozan A., Sehirli O., Omurtag G.Z., Cetinel S.,
Gedik N., Sener G., Ginkgo biloba extract reduces naphthalene-induced oxidative damage in mice.
Phytother. Res., 2007, 21, 72–77
[34] Hanigan M.H., Devarajan P., Cisplatin nephrotoxicity:
molecular mechanisms. Cancer Ther., 2003, 1, 47–61
[35] Longoni B., Giovannini L., Migliori M., Bertelli A.A., Bertelli A., Cyclosporine-induced lipid peroxidation and propionyl carnitine protective effect. Int. J.
Tissue React., 1999, 21, 7–11
[36] Ferrari R., Merli E., Cicchitelli G., Mele D., Fucili A., Ceconi C., Therapeutic effects of L-carnitine and propionyl-L-carnitine on cardiovascular diseases: A review. Ann. N.Y. Acad. Sci., 2004, 1033, 79–91 [37] Sener G., Paskaloglu K., Satiroglu H., Alican I.,
Kacmaz A., Sakarcan A. , L-carnitine ameliorates oxidative damage due to chronic renal failure in rats.
J. Cardiovasc. Pharmacol., 2004, 43, 698–705 [38] Lu Y., Cederbaum A., The mode of cisplatin-induced
cell death in CYP2E1-overexpressing HepG2 cells: modulation by ERK, ROS, glutathione, and thioredoxin. Free Radic. Biol. Med., 2007, 43, 1061–1075
[39] Bompart G., Cisplatin-induced changes in cytochrome P-450, lipid peroxidation and drug- metabolizing enzyme activities in rat kidney cortex.
Toxicol. Lett., 1989, 48, 193–199
[40] Nannelli A., Messina A., Marini S., Trasciatti S., Longo V., Gervasi P.G., Effects of the anticancer dehydrotarplatin on cytochrome P450 and antioxidant enzymes in male rat tissues. Arch.
Toxicol., 2007, 81, 479–487
[41] Arafa H.M., Carnitine deficiency aggravates carboplatin nephropathy through deterioration of energy status, oxidant/anti-oxidant balance, and inflammatory endocoids. Toxicology, 2008, 254 (1-2), 51–60
[42] Kart A., Yapar K., Karapehlivan M., Citil M., The possible protective effect of L-carnitine on tilmicosin-induced cardiotoxicity in mice. J. Vet.
Med. A, 2006, 54, 144–146
[43] Bianchi G., Vitali G., Caraceni A., Ravaglia S., Capri G., Cundari S., et al., Symptomatic and neurophysiological responses of paclitaxel- or cisplatin-induced neuropathy to oral acetyl- L-carnitine. Eur. J. Cancer., 2005, 41(12), 1746–1750
[44] Yuce A., Atessahin A., Ceribasi A.O., Aksakal M., Ellagic acid prevents cisplatin-induced oxidative stress in liver and heart tissue of rats. Basic Clin.
Pharmacol. Toxicol., 2007, 101, 345–349
