Effects of antioxidants and Ca2+ in cisplatin-induced cell injury in rabbit renal cortical slices

Platinum iodido drugs show potential anti-tumor activity, affecting cancer cell metabolism and inducing ROS and senescence in gastrointestinal cancer cells

Cisplatin-based chemotherapy has associated clinical disadvantages, such as high toxicity and resistance. Thus, the development of new antitumor metallodrugs able to overcome different clinical barriers is a public healthcare priority. Here, we studied the mechanism of action of the isomers trans and cis-[PtI2(isopropylamine)2] (I5 and I6, respectively) against gastrointestinal cancer cells. We demonstrate that I5 and I6 modulate mitochondrial metabolism, decreasing OXPHOS activity and negatively affecting ATP-linked oxygen consumption rate. Consequently, I5 and I6 generated Reactive Oxygen Species (ROS), provoking oxidative damage and eventually the induction of senescence. Thus, herein we propose a loop with three interconnected processes modulated by these iodido agents: (i) mitochondrial dysfunction and metabolic disruptions; (ii) ROS generation and oxidative damage; and (iii) cellular senescence. Functionally, I5 reduces cancer cell clonogenicity and tumor growth in a pancreatic xenograft model without systemic toxicity, highlighting a potential anticancer complex that warrants additional pre-clinical studies.

Uncovering the cytotoxic effects of air pollution with multi-modal imaging of in vitro respiratory models

Annually, an estimated seven million deaths are linked to exposure to airborne pollutants. Despite extensive epidemiological evidence supporting clear associations between poor air quality and a range of short- and long-term health effects, there are considerable gaps in our understanding of the specific mechanisms by which pollutant exposure induces adverse biological responses at the cellular and tissue levels. The development of more complex, predictive, in vitro respiratory models, including two- and three-dimensional cell cultures, spheroids, organoids and tissue cultures, along with more realistic aerosol exposure systems, offers new opportunities to investigate the cytotoxic effects of airborne particulates under controlled laboratory conditions. Parallel advances in high-resolution microscopy have resulted in a range of in vitro imaging tools capable of visualizing and analysing biological systems across unprecedented scales of length, time and complexity. This article considers state-of-the-art in vitro respiratory models and aerosol exposure systems and how they can be interrogated using high-resolution microscopy techniques to investigate cell-pollutant interactions, from the uptake and trafficking of particles to structural and functional modification of subcellular organelles and cells. These data can provide a mechanistic basis from which to advance our understanding of the health effects of airborne particulate pollution and develop improved mitigation measures.

Methylene Blue Induces Antioxidant Defense and Reparation of Mitochondrial DNA in a Nrf2-Dependent Manner during Cisplatin-Induced Renal Toxicity

Cisplatin is a platinum-based cytostatic drug that is widely used for cancer treatment. Mitochondria and mtDNA are important targets for platinum-based cytostatics, which mediates its nephrotoxicity. It is important to develop therapeutic approaches to protect the kidneys from cisplatin during chemotherapy. We showed that the exposure of mitochondria to cisplatin increased the level of lipid peroxidation products in the in vitro experiment. Cisplatin caused strong damage to renal mtDNA, both in the in vivo and in vitro experiments. Cisplatin injections induced oxidative stress by depleting renal antioxidants at the transcriptome level but did not increase the rate of H₂O₂ production in isolated mitochondria. Methylene blue, on the contrary, induced mitochondrial H₂O₂ production. We supposed that methylene blue-induced H₂O₂ production led to activation of the Nrf2/ARE signaling pathway. The consequences of activation of this signaling pathway were manifested in an increase in the expression of some antioxidant genes, which likely caused a decrease in the amount of mtDNA damage. Methylene blue treatment induced an increase in the expression of genes that were involved in the base excision repair (BER) pathway: the main pathway for mtDNA reparation. It is known that the expression of these genes can also be regulated by the Nrf2/ARE signaling pathway. We can assume that the protective effect of methylene blue is related to the activation of Nrf2/ARE signaling pathways, which can activate the expression of genes related to antioxidant defense and mtDNA reparation. Thus, the protection of kidney mitochondria from cisplatin-induced damage using methylene blue can significantly expand its application in medicine.

Platinum-based drug-induced depletion of amino acids in the kidneys and liver

Cisplatin (cis-diamminedichloroplatinum II; CDDP) is a widely used cytostatic agent; however, it tends to promote kidney and liver disease, which are a major signs of drug-induced toxicity. Platinum compounds are often presented as alternative therapeutics and subsequently easily dispersed in the environment as contaminants. Due to the major roles of the liver and kidneys in removing toxic materials from the human body, we performed a comparative study of the amino acid profiles in chicken liver and kidneys before and after the application of CDDP and platinum nanoparticles (PtNPs-10 and PtNPs-40). The treatment of the liver with the selected drugs affected different amino acids; however, Leu and Arg were decreased after all treatments. The treatment of the kidneys with CDDP mostly affected Val; PtNPs-10 decreased Val, Ile and Thr; and PtNPs-40 affected only Pro. In addition, we tested the same drugs on two healthy cell lines, HaCaT and HEK-293, and ultimately explored the amino acid profiles in relation to the tricarboxylic acid cycle (TCA) and methionine cycle, which revealed that in both cell lines, there was a general increase in amino acid concentrations associated with changes in the concentrations of the metabolites of these cycles.

Oxidative DNA Damage and Cisplatin Neurotoxicity Is Exacerbated by Inhibition of OGG1 Glycosylase Activity and APE1 Endonuclease Activity in Sensory Neurons

Cisplatin can induce peripheral neuropathy, which is a common complication of anti-cancer treatment and negatively impacts cancer survivors during and after completion of treatment; therefore, the mechanisms by which cisplatin alters sensory neuronal function to elicit neuropathy are the subject of much investigation. Our previous work suggests that the DNA repair activity of APE1/Ref-1, the rate-limiting enzyme of the base excision repair (BER) pathway, is critical for neuroprotection against cisplatin. A specific role for 8-oxoguanine DNA glycosylase-1 (OGG1), the glycosylase that removes the most common oxidative DNA lesion, and putative coordination of OGG1 with APE1/Ref-1 in sensory neurons, has not been investigated. We investigated whether inhibiting OGG1 glycosylase activity with the small molecule inhibitor, TH5487, and/or APE1/Ref-1 endonuclease activity with APE Repair Inhibitor III would alter the neurotoxic effects of cisplatin in sensory neuronal cultures. Sensory neuron function was assessed by calcitonin gene-related peptide (CGRP) release, as a marker of sensitivity and by neurite outgrowth. Cisplatin altered neuropeptide release in an inverse U-shaped fashion, with low concentrations enhancing and higher concentrations diminishing CGRP release. Pretreatment with BER inhibitors exacerbated the functional effects of cisplatin and enhanced 8oxo-dG and adduct lesions in the presence of cisplatin. Our studies demonstrate that inhibition of OGG1 and APE1 endonuclease activity enhances oxidative DNA damage and exacerbates neurotoxicity, thus limiting oxidative DNA damage in sensory neurons that might alleviate cisplatin-induced neuropathy.

Mollification of Doxorubicin (DOX)-Mediated Cardiotoxicity Using Conjugated Chitosan Nanoparticles with Supplementation of Propionic Acid

Doxorubicin is an extensively prescribed antineoplastic agent. It is also known for adverse effects, among which cardiotoxicity tops the list. The possible mechanism underlying doxorubicin (DOX)-mediated cardiotoxicity has been investigated in this study. Further, to reduce the DOX-mediated cardiotoxicity, DOX was conjugated with Chitosan Nanoparticles (DCNPs) and supplemented with propionic acid. Initially, the drug loading efficacy and conjugation of DOX with chitosan was confirmed by UV–Visible Spectroscopy (UV) and Fourier Transform Infrared Spectroscopy (FTIR). The average sizes of the synthesized Chitosan Nanoparticles (CNPs) and DCNPs were measured by Dynamic Light Scattering (DLS) analysis as 187.9 ± 1.05 nm and 277.3 ± 8.15 nm, respectively, and the zeta potential values were recorded as 55.2 ± 0.7 mV and 51.9 ± 1.0 mV, respectively. The size and shape of CNPs and DCNPs were recorded using a High-Resolution Electron Microscopy (HRTEM). The particles measured <30 nm and 33–84 nm, respectively. The toxic effects of DCNPs and propionic acid were evaluated in rat model. The data from the electrocardiogram (ECG), cardiac biomarkers, Peroxisome proliferator-activated receptor gamma (PPARγ) and histological observations indicated evidence of DOX-mediated cardiotoxicity, whereas the administration of DCNPs, as well as Propionic Acid (PA), brought about a restoration to normalcy and offered protection in the context of DOX-induced cardiotoxicity.

Mechanisms of cardiovascular toxicity induced by PM2.5: a review

An increasing number of studies have shown that exposure to particulate matter with a diameter ≤ 2.5 μm (PM_2.5) could affect the onset and development of cardiovascular diseases. To explore the underlying mechanisms, the studies conducted in vitro investigations using different cell lines. In this review, we examined recently published reports cited by PubMed or Web of Science on the topic of cardiovascular toxicity induced by PM_2.5 that carried the term in vitro. Here, we summarized the suggested mechanisms of PM_2.5 leading to adverse effects and cardiovascular toxicity including oxidative stress; the increase of vascular endothelial permeability; the injury of vasomotor function and vascular reparative capacity in vascular endothelial cell lines; macrophage polarization and apoptosis in macrophage cell lines; and hypermethylation and apoptosis in the AC16 cell line and the related signaling pathways, which provided a new research direction of cardiovascular toxicity of PM_2.5.

Synergistic Anti-cancer Activity of MH-30 in a Murine Melanoma Model Treated With Cisplatin and its Alleviated Effects Against Cisplatin-induced Toxicity in Mice

BACKGROUND/AIM

Although cisplatin is an effective anticancer drug, its toxic effects on normal tissues limit its use. We developed a herbal formula, MH-30, with increased fat-soluble polyphenols by improving the manufacturing method of HemoHIM. In this study, we examined whether the combination of MH-30 with cisplatin exerts synergistic antitumor effect while it reduces cisplatin-induced toxicities.

MATERIALS AND METHODS

MH-30 was produced by adding the ethanol-insoluble fraction to its extract after decocting herbs in 30% ethanol and water. We used a melanoma-bearing mice model to investigate synergistic anticancer effects. The NK cell activity and cytokine levels were measured by Cr⁵¹-release assay and ELISA. The AST, ALT, BUN, and creatinine levels were estimated in the serum.

RESULTS

MH-30 effectively inhibited melanoma growth in vitro. Furthermore, MH-30 had a synergistic effect in combination with cisplatin on melanoma growth inhibition in vitro and in vivo. In melanoma-bearing mice, cisplatin alone decreased the activity of NK cells and the levels of IL-2 and IFN-γ, which were effectively restored by the combination of MH-30 with cisplatin. Combined treatment with MH-30 and cisplatin significantly inhibited the cisplatin-induced increase in the levels of AST, ALT, BUN, and creatinine.

CONCLUSION

Combination of MH-30 with cisplatin may be a beneficial anticancer treatment with reduced adverse effects.

The association of ambient PM2.5 with school absence and symptoms in schoolchildren: a panel study

BACKGROUND

Children are a susceptible population to exposure of ambient fine particulate air pollution (PM_2.5), and the associated symptoms are sensitive prevalent indicators of morbidity. However, few studies to date investigate the association between PM_2.5 exposure and school absence and symptoms.

METHODS

In a panel study including 20,291 observations in 615 schoolchildren 8-13 years of age, we asked the participants to record their school absence and symptoms on every school day from 17 November to 31 December 2014 in Jinan, China. We used the generalized linear mixed effects models to examine the adverse effects of ambient PM_2.5 on school absence and symptoms, adjusting for covariates including meteorological and individual factors.

RESULTS

The 3-day moving average of PM_2.5 was significantly associated with school absence (1.37; 95% CI: 1.07-1.74) and increases in symptoms of the throat (1.03; 95% CI: 1.00-1.05), nose (1.03; 95% CI: 1.01-1.06), and skin (1.09; 95% CI: 1.06-1.12). High PM_2.5 exposure also increased the risks of individual symptoms, especially for cough (1.02; 95% CI: 1.00-1.04), sneezing (1.03; 95% CI: 1.00-1.07), and stuffy nose (1.09; 95% CI: 1.02-1.17).

CONCLUSION

High PM_2.5 exposure is a risk factor for the health of schoolchildren. Allocation of medical resources for children should take into account the ambient PM_2.5 concentrations and be proportioned accordingly.

Hepatoprotective effects of capping protein gelsolin against hyperoxia-induced hepatotoxicity, oxidative stress and DNA damage in neonatal rats

Tissues and organs get exposed to high oxygen (O₂) supply in hyperoxia conditions. The goal of this research was to investigate the protective effect of actin binding protein gelsolin on hyperoxia-induced hepatotoxicity through histopathology and measurement of oxidative stress parameters and DNA damage in a neonatal Wistar albino rats. The pups were randomly separated to four equal groups such as: normoxia control group (NC), normoxia plus gelsolin group (NG, 10 ng/kg bw/day gelsolin), hyperoxia (≥85% O₂) group (HC), hyperoxia plus gelsolin group (HG, ≥85% O₂; 10 ng/kg bw/day gelsolin). Histopathological changes of pups in hyperoxia condition were revealed in the form of severe leukocyte infiltration, vascular congestion, necrosis, vacuolar degeneration, binucleated hepatocytes and hemorrhage in the liver tissue. SOD, CAT, GPx and GST activities decreased and MDA level increased in the hyperoxia-induced group in liver tissue (P < 0.05). Tail DNA%, tail length and moment indicating DNA damage statistically increased in hyperoxia treatment groups when compared to controls. Treatment of rats with hyperoxia plus gelsolin prevented hyperoxia-induced changes in tissue structure, antioxidant enzyme activities and MDA level, mean tail DNA% and length. Based on these findings, gelsolin restored these changing to near normal levels but it does not protect completely in the hyperoxia conditions.

Ameliorative effects of pine bark extract on cisplatin-induced acute kidney injury in rats

Objective: This study investigated the dose–response effects of pine bark extract (PBE, pycnogenol^®) on oxidative stress-mediated apoptotic changes induced by cisplatin (Csp) in rats.

Materials and methods: The ameliorating potential of PBE was evaluated after orally administering PBE at doses of 10 or 20 mg/kg for 10 days. Acute kidney injury was induced by a single intraperitoneal injection of Csp at 7 mg/kg on test day 5.

Results: Csp treatment caused acute kidney injury manifested by elevated levels of serum blood urea nitrogen (BUN) and creatinine (CRE) with corresponding histopathological changes, including degeneration of tubular epithelial cells, hyaline casts in the tubular lumen, and inflammatory cell infiltration (interstitial nephritis). Csp also induced significant apoptotic changes in renal tubular cells. In addition, Csp treatment induced high levels of oxidative stress, as evidenced by an increased level of malondialdehyde, depletion of the reduced glutathione (GSH) content, and decreased activities of glutathione S-transferase, superoxide dismutase, and catalase in kidney tissues. On the contrary, PBE treatment lowered BUN and CRE levels and effectively attenuated histopathological alterations and apoptotic changes induced by Csp. Additionally, treatment with PBE suppressed lipid peroxidation, prevented depletion of GSH, and enhanced activities of the antioxidant enzymes in kidney tissue.

Conclusions: These results indicate that PBE has a cytoprotective effect against oxidative stress-mediated apoptotic changes caused by Csp in the rat kidney, which may be attributed to both increase of antioxidant enzyme activities and inhibition of lipid peroxidation.

Efficacy of safranal to cisplatin-induced nephrotoxicity

The aim of the present study was to investigate the effects of safranal on cisplatin-induced nephrotoxicity and oxidative stress in rats. Adult male Sprague–Dawley rats were randomly divided into five groups. The control group received physiological saline; animals in Group 2 received only safranal and in Group 3 received only cisplatin; 5 days of safranal treatment was performed following administration of cisplatin for the animals in Group 4; 5 days of safranal pretreatment was applied to the animals in Group 5 before administration of cisplatin. Cisplatin (7 mg/kg) was intraperitoneally injected as a single dose and safranal (200 mg/kg) was administered by gavage. Biochemical and histopathological methods were utilized for evaluation of the nephrotoxicity. The concentrations of creatinine and urea in plasma and levels of malondialdehyde (MDA) and glutathione (GSH) as well as total antioxidant status (TAS) and total oxidant status (TOS) were determined in kidney tissue. Administration of cisplatin to rats induced a marked renal failure, characterized with a significant increase in plasma creatinine and urea concentrations. MDA and TOS levels of rats that received cisplatin alone were not significantly different compared with those of the control group, but GSH and TAS levels in the only cisplatin-administered group were significantly decreased. Safranal administration produced amelioration in biochemical indices of nephrotoxicity in both plasma and kidney tissues when compared with the only cisplatin-administered group, pretreatment with safranal being more effective. As a result, safranal treatment might have a protective effect against cisplatin-induced nephrotoxicity and oxidative stress in rat.

A Comprehensive Review on the Genetic Regulation of Cisplatin-induced Nephrotoxicity

Cisplatin (CDDP) is a well-known antineoplastic drug which has been extensively utilized over the last decades in the treatment of numerous kinds of tumors. However, CDDP induces a wide range of toxicities in a dose-dependent manner, among which nephrotoxicity is of particular importance. Still, the mechanism of CDDP-induced renal damage is not completely understood; moreover, the knowledge about the role of microRNAs (miRNAs) in the nephrotoxic response is still unknown. miRNAs are known to interact with the representative members of a diverse range of regulatory pathways (including postnatal development, proliferation, inflammation and fibrosis) and pathological conditions, including kidney diseases: polycystic kidney diseases (PKDs), diabetic nephropathy (DN), kidney cancer, and drug-induced kidney injury. In this review, we shed light on the following important aspects: (i) information on genes/proteins and their interactions with previously known pathways engaged with CDDP-induced nephrotoxicity, (ii) information on newly discovered biomarkers, especially, miRNAs for detecting CDDP-induced nephrotoxicity and (iii) information to improve our understanding on CDDP. This information will not only help the researchers belonging to nephrotoxicity field, but also supply an indisputable help for oncologists to better understand and manage the side effects induced by CDDP during cancer treatment. Moreover, we provide up-to-date information about different in vivo and in vitro models that have been utilized over the last decades to study CDDP-induced renal injury. Taken together, this review offers a comprehensive network on genes, miRNAs, pathways and animal models which will serve as a useful resource to understand the molecular mechanism of CDDP-induced nephrotoxicity.

The impact of PM2.5 on the human respiratory system

Recently, many researchers paid more attentions to the association between air pollution and respiratory system disease. In the past few years, levels of smog have increased throughout China resulting in the deterioration of air quality, raising worldwide concerns. PM2.5 (particles less than 2.5 micrometers in diameter) can penetrate deeply into the lung, irritate and corrode the alveolar wall, and consequently impair lung function. Hence it is important to investigate the impact of PM2.5 on the respiratory system and then to help China combat the current air pollution problems. In this review, we will discuss PM2.5 damage on human respiratory system from epidemiological, experimental and mechanism studies. At last, we recommend to the population to limit exposure to air pollution and call to the authorities to create an index of pollution related to health.

Hepatotoxicity and pharmacokinetics of cisplatin in combination therapy with a traditional Chinese medicine compound of Zengmian Yiliu granules in ICR mice and SKOV-3-bearing nude mice

BACKGROUND

Cisplatin (CDDP) is a highly effective chemotherapeutic agent used for therapy of many tumors and has been limited by its toxicity. Zengmian Yiliu granule (ZMYL), a compound preparation of traditional Chinese medicines, has been used in clinic as a complementary and alternative medicine for attenuating CDDP-induced toxicities and enhancing the tumor therapeutic effect of CDDP. The aim of the present study is to investigate hepaprotective effect of ZMYL against CDDP-induced hepatotoxicity. Further, the pharmacokinetic characteristics of CDDP in SKOV-3-bearing nude mice were observed.

METHODS

The ICR mice were dosed orally with ZMYL for 7 days and then CDDP was injected intraperitoneally at a dose of 45 mg/kg body weight. The serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured to evaluate the liver function. The total glutathione (T-GSH), reduced glutathione (GSH) and glutathione S-transferase (GST) levels were determined to evaluate the oxidant damage in liver homogenates. Tissue pathological change in liver was conducted by light microscopy analysis. The pharmacokinetic and tissue distribution of free and total platinum (Pt) after dosing of CDDP alone and combination with ZMYL were determined in SKOV-3-bearing nude mice by ICP-MS.

RESULTS

Oral administration of ZMYL prior to the CDDP treatment could prevent the CDDP-induced in lifting of ALT and AST, reduction of T-GSH, R-GSH and GST, and some histopathological alterations in ICR mice. Some differences in pharmacokinetic parameters between the two groups have been observed in higher CL and decreased MRT of free platinum (Pt) in plasma and total Pt in spleen in CDDP co-administration with ZMYL group. It indicated CDDP was cleared more quickly from blood and spleen, and could reduce the accumulation and toxic possibility of CDDP in combination with ZMYL.

CONCLUSIONS

ZMYL could be used as a beneficial supplement, which could attenuate CDDP-induced hepatotoxicity during CDDP chemotherapy and did not disturb the pharmacokinetics fate of CDDP significantly.

Effect of lycopene against cisplatin-induced acute renal injury in rats: organic anion and cation transporters evaluation

In the present study, we investigated the effects of lycopene on the expression of organic anion transporters (OATs), organic cation transporters (OCTs), and multidrug resistance-associated proteins (MRPs) of cisplatin-induced nephrotoxicity in rats. Twenty-eight 8-week-old Wistar rats were divided into four groups: control, lycopene-treated (6 mg/kg BW by oral gavage), cisplatin-treated (7 mg/kg BW, IP), and lycopene in combination with cisplatin-treated groups. In the presence of cisplatin, serum urea nitrogen (urea-N) (48.5 vs. 124.3 mg/dl) and creatinine (0.29 vs. 1.37 mg/dl) levels and the kidney efflux transporters MRP2 and MRP4 levels were significantly increased, whereas OAT1, OAT3, OCT1, and OCT2 levels in kidney were decreased in the treated rats compared with normal control rats. However, administration of lycopene in combination with cisplatin resulted in a reduction in the serum urea-N (124.3 vs. 62.4) and creatinine (1.37 vs. 0.40) levels and the kidney efflux transporters MRP2 and MRP4 proteins in the kidneys. Administration of lycopene to acute renal injury-induced rats largely upregulated the organic anion transporters (OAT1 and 3) and organic cation transporters (OCT1 and 2) to decrease the side effects of cisplatin. The present study suggests that lycopene synergizes with its nephroprotective effect against cisplatin-induced acute kidney injury in rats.

Amelioration of cisplatin-induced nephrotoxicity by statins

Objectives:

This study aimed to investigate the protective effect of simvastatin (SIM) and rosuvastatin (RST) on cisplatin (CIS)-induced nephrotoxicity.

Materials and Methods:

Adult female Wistar rats were divided into six groups: Control group (Group 1) received 0.5% sodium carboxy methyl cellulose, group 2 and group 3 received SIM and RST for 10 days, respectively, and group 4 was injected single dose of CIS (7 mg/kg, i.p.). Group 5 and 6 were treated with SIM (10 mg/kg, p.o.) and RST (10 mg/kg, p.o.) for 10 days, respectively. All groups received cisplatin on the 5^th day of treatment. Renal function tests like serum creatinine, urea, BUN, albumin, calcium, uric acid and magnesium, serum lipids, and markers of oxidative stress such as renal malondialdehyde (MDA) level and superoxide dismutase (SOD) and catalase (CAT) activities were measured. All tissues were investigated for histopathological changes.

Result:

CIS reduced the renal function, which was reflected with significant increase in serum urea, BUN, serum creatinine, uric acid and also significant decrease serum calcium, magnesium, albumin levels. In addition, cisplatin caused renal tubular damage with a higher MDA level, depletion of SOD and CAT activity, and elevation of serum lipids. SIM or RST ameliorate CIS induced renal damage due to improvement in renal function, oxidative stress, suppression of serum lipids, and histological alteration.

Conclusions:

This finding suggests that simvastatin and rosuvastatin may have a protective effect against cisplatin-induced kidney damage via amelioration of lipid peroxidation as well as due to improvement of renal function, and lipid-lowering effects.

Antineoplastic drug, carboplatin, protects mice against visceral leishmaniasis

In the present study, the leishmanicidal effect of two doses (5 and 10 mg/kg body weight) of the carboplatin was studied in Leishmania donovani-infected BALB/c mice. Mice were infected intracardially with promastigotes of L. donovani, and a month after infection, they were treated intraperitoneally with the two doses of the drug (5 and 10 mg/kg body weight) for five continuous days. Animals were sacrificed on 1 and 15 posttreatment days. Hepatic parasite load was assessed on Geimsa-stained imprints. Immune responses were studied by measuring delayed-type hypersensitivity (DTH) responses, serum IgG isotype levels (IgG1 and IgG2a) and cytokine levels [γ-interferon (IFN-γ), interleukin (IL)-10 and IL-2] in spleen cell cultures by ELISA. To study the drug-induced side effects, various haematological (haemoglobin and total leukocyte count), biochemical (liver and kidney function tests) and histological investigations (kidney, liver and spleen) were carried out. The antileishmanial potential of the drug was revealed by significant reduction in the parasite burden. The infected and treated animals were also found to exhibit increased DTH responses, higher IgG2a levels, lower IgG1 levels and greater cytokine (IFN-γ, IL-10 and IL-2) concentrations pointing towards the generation of mixed Th1/Th2 response. Liver and kidney function tests and histological studies of kidney, liver and spleen of treated mice revealed no side effects. Carboplatin cures mice of visceral leishmaniasis without causing any serious side effects, and the drug was found be more effective at a dose of 10 mg/kg body weight as compared to 5 mg/kg body weight.

Lipid peroxidative damage on Cisplatin exposure and alterations in antioxidant defense system in rat kidneys: a possible protective effect of selenium

Cisplatin (Cis-diamminedichloroplatinum II, CP) is an important chemotherapeutic agent, useful in the treatment of several cancers, but with several side effects such as nephrotoxicity. The present study investigated the possible protective effect of selenium (Se) against CP-induced oxidative stress in the rat kidneys. Male Wistar albino rats were injected with a single dose of cisplatin (7 mg CP/kg b.m., i.p.) and selenium (6 mg Se/kg b.m, as Na₂SeO₃, i.p.), alone or in combination. The obtained results showed that CP increased lipid peroxidation (LPO) and decreased reduced glutathione (GSH) concentrations, suggesting the CP-induced oxidative stress, while Se treatment reversed this change to control values. Acute intoxication of rats with CP was followed by statistically significant decreased activity of antioxidant defense enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione-S-transferase (GST). Treatment with Se reversed CP-induced alterations of antioxidant defense enzyme activities and significantly prevented the CP-induced kidney damage.

Cyclophosphamide and ascorbic acid-mediated ultrastructural and biochemical changes in Dalton's lymphoma cells in vivo

Cyclophosphamide, an antineoplastic drug effective against a wide variety of cancers is cytotoxic to normal cells also. Ascorbic acid (vitamin C) at higher concentrations possesses cytotoxic effects and it can also enhance the cytotoxicity of 5-fluorouracil in a dose-dependent manner in mouse lymphoma. In the present study, effect of cyclophosphamide treatment alone and in combination with ascorbic acid in vivo on the ultrastructure and some biochemical changes in Dalton's lymphoma tumor cells were investigated. Cyclophosphamide treatment causes disappearance of cell membrane processes, thickening and reduction in the number of mitochondrial cristae as well as the manifestation of rounded shape of mitochondria. The combination treatment with ascorbic acid plus cyclophosphamide caused further changes in tumor cells showing disintegration in the cell surface membrane, disruption in the nuclear membrane and roundish mitochondria with reduction and disruption in the mitochondrial cristae. The observed ascorbic acid plus cyclophosphamide-mediated decrease in reduced glutathione (GSH) in tumor cells may play an important role in the antitumor activity of cyclophosphamide by weakening cellular antioxidant-mediated defense mechanism, thereby increasing tumor cell's susceptibility to cell death. The cyclophosphamide-mediated decrease in lactate dehydrogenase activity in tumor cells and simultaneous increase in ascites supernatant may possibly indicate alteration in the membrane permeability of tumor cells for lactate dehydrogenase as well as tumor cell injury. Further investigation should determine detailed mechanism(s) involved in cyclophosphamide-induced ultrastructural and biochemical changes in tumor cells.

Crocin attenuates cisplatin-induced renal oxidative stress in rats

Reactive oxygen species (ROS) and oxidative damage are the most important factors in cisplatin-induced acute renal failure. This study examined the protective effects of crocin against cisplatin-induced renal oxidative stress in rat. Animals were divided into five groups (n=6). Group 1 received normal saline (2 ml/day, i.p.). Group 2 received a single dose of cisplatin (5mg/kg, i.p.). Groups 3-5 received crocin (100, 200, and 400mg/kg, i.p., respectively) for four consecutive days beginning 1-h before a single dose of cisplatin (5mg/kg) on day 1. On day 5, blood samples were drawn and kidneys were removed for histopathological, biochemical and RT-PCR examinations. Twenty four hours urinary chemistries were measured. Blood urea and creatinine and urinary glucose and protein concentrations in crocin-treated groups were significantly lower compared to the cisplatin-treated group. Histopathological studies showed massive damage in the S(3) segment of proximal tubules in cisplatin-treated group but not in crocin-treated groups. Crocin treatment resulted in a significant reduction in malondialdehyde (MDA) concentration and produced a significant elevation in total thiol and glutathione peroxidase concentrations. There was a significant elevation in the mRNA expression of glutathione peroxidase in crocin-treated groups. The results suggest that crocin attenuates cisplatin-induced renal oxidative stress in rats.

The protective effect of royal jelly against cisplatin-induced renal oxidative stress in rats

BACKGROUND

The aim of this study was to investigate the effects of royal jelly on cisplatin-induced nephrotoxicity and oxidative stress in rats.

METHODS

Adult male Wistar albino rats were randomly divided into eight groups: the control, cisplatin, royal jelly, and royal jelly plus cisplatin groups. Biochemical and histopathological methods were utilized for evaluation of the nephrotoxicity. Blood was collected and analyzed for blood urea nitrogen (BUN), alanine aminotransferase, aspartate aminotransferase, triglyceride, total cholesterol, uric acid, total bilirubin, and total protein levels. The kidney samples were stored for the measurement of malondialdehyde (MDA), glutathione peroxidase (GSHPx), superoxide dismutase (SOD), and catalase (CAT) activities and processed for histopathological examinations.

RESULTS

Administration of cisplatin to rats induced a marked renal failure, characterized with a significant increase in serum BUN and uric acid concentrations, and they had higher kidney MDA and lower GSH-Px, SOD, and CAT activities. In the groups that were administered RJ in association with CP, improvement was observed in some oxidative stress parameters and certain other biochemical parameters, pre-treatment with RJ being more effective.

CONCLUSIONS

The CP-induced changes in histopathologic findings of kidneys were partially reversed by treatment with royal jelly. The results provide further insight into the mechanisms of CP-induced nephrotoxicity and confirm the antioxidant potential of royal jelly.

Amelioration of cisplatin-induced nephrotoxicity by extracts of Hemidesmus indicus and Acorus calamus

Administration of commonly used anticancer drug cisplatin [cis-diamminedichloroplatinum (II)] at pharmacologically relevant concentrations (12 mg/kg body weight) resulted in severe renal toxicity as evidenced from histopathological observations and biochemical alterations in the renal tissue. The extracts of medicinal plants Hemidesmus indicus L. (Apocynaceae) and Acorus calamus L. (Araceae) protected the renal tissue effectively from cisplatin-induced toxicity. Treatment of cisplatin-administered animals with the plant extracts could prevent the drug-induced oxidative damage in the renal tissue as evidenced from the decreased levels of lipid peroxidation and enhanced activities of the antioxidants in the renal tissue. Cisplatin treatment increased serum urea level to 41.3 +/- 2.86 mg/dL and administration of the extracts of H. indicus and A. calamus brought down the level to 34.54 +/- 0.37 and 30.12 +/- 0.95 mg/dL, respectively. Serum creatinine levels were increased to 1.1 +/- 0.02 mg/dL following cisplatin administration, and treatment with extracts of H. indicus and A. calamus brought this down to 0.76 +/- 0.09 and 0.61 +/- 0.06 mg/dL, respectively. The histopathological observations indicated that treatment with the H. indicus and A. calamus extracts restored the cisplatin-induced structural alterations in the renal tissue.

Chemopreventive and renal protective effects for docosahexaenoic acid (DHA): implications of CRP and lipid peroxides

Background

The fish oil-derived ω-3 fatty acids, like docosahexanoic (DHA), claim a plethora of health benefits. We currently evaluated the antitumor effects of DHA, alone or in combination with cisplatin (CP) in the EAC solid tumor mice model, and monitored concomitant changes in serum levels of C-reactive protein (CRP), lipid peroxidation (measured as malondialdehyde; MDA) and leukocytic count (LC). Further, we verified the capacity of DHA to ameliorate the lethal, CP-induced nephrotoxicity in rats and the molecular mechanisms involved therein.

Results

EAC-bearing mice exhibited markedly elevated LC (2-fold), CRP (11-fold) and MDA levels (2.7-fold). DHA (125, 250 mg/kg) elicited significant, dose-dependent reductions in tumor size (38%, 79%; respectively), as well as in LC, CRP and MDA levels. These effects for CP were appreciably lower than those of DHA (250 mg/kg). Interestingly, DHA (125 mg/kg) markedly enhanced the chemopreventive effects of CP and boosted its ability to reduce serum CRP and MDA levels. Correlation studies revealed a high degree of positive association between tumor growth and each of CRP (r = 0.85) and leukocytosis (r = 0.89), thus attesting to a diagnostic/prognostic role for CRP.

On the other hand, a single CP dose (10 mg/kg) induced nephrotoxicity in rats that was evidenced by proteinuria, deterioration of glomerular filtration rate (GFR, -4-fold), a rise in serum creatinine/urea levels (2–5-fold) after 4 days, and globally-induced animal fatalities after 7 days. Kidney-homogenates from CP-treated rats displayed significantly elevated MDA- and TNF-α-, but reduced GSH-, levels. Rats treated with DHA (250 mg/kg, but not 125 mg/kg) survived the lethal effects of CP, and showed a significant recovery of GFR; while their homogenates had markedly-reduced MDA- and TNF-α-, but -increased GSH-levels. Significant association was detected between creatinine level and those of MDA (r = 0.81), TNF-α ) r = 0.92) and GSH (r = -0.82); implying causal relationships.

Conclusion

DHA elicited prominent chemopreventive effects on its own, and appreciably augmented those of CP as well. The extent of tumor progression in various mouse groups was highly reflected by CRP levels (thus implying a diagnostic/prognostic role for CRP). Further, this study is the first to reveal that DHA can obliterate the lethal CP-induced nephrotoxicity and renal tissue injury. At the molecular level, DHA appears to act by reducing leukocytosis, systemic inflammation, and oxidative stress.

Enhanced antitumor efficacy of cisplatin in combination with HemoHIM in tumor-bearing mice

Background

Although cisplatin is one of the most effective chemotherapeutic agents, cisplatin alone does not achieve a satisfactory therapeutic outcome. Also cisplatin accumulation shows toxicity to normal tissues. In this study, we examined the possibility of HemoHIM both to enhance anticancer effect with cisplatin and to reduce the side effects of cisplatin in melanoma-bearing mice.

Methods

HemoHIM was prepared by adding the ethanol-insoluble fraction to the total water extract of a mixture of 3 edible herbs, Angelica Radix, Cnidium Rhizoma and Paeonia Radix. Anticancer effects of HemoHIM with cisplatin were evaluated in melanoma-bearing mice. We used a Cr⁵¹-release assay to measure the activity of NK/Tc cell and ELISA to evaluate the production of cytokines.

Results

In melanoma-bearing mice, cisplatin (4 mg/kg B.W.) reduced the size and weight of the solid tumors, and HemoHIM supplementation with cisplatin enhanced the decrease of both the tumor size (p < 0.1) and weight (p < 0.1). HemoHIM itself did not inhibit melanoma cell growth in vitro, and did not disturb the effects of cisplatin in vitro. However HemoHIM administration enhanced both NK cell and Tc cell activity in mice. Interestingly, HemoHIM increased the proportion of NK cells in the spleen. In melanoma-bearing mice treated with cisplatin, HemoHIM administration also increased the activity of NK cells and Tc cells and the IL-2 and IFN-γ secretion from splenocytes, which seemed to contribute to the enhanced efficacy of cisplatin by HemoHIM. Also, HemoHIM reduced nephrotoxicity as seen by tubular cell of kidney destruction.

Conclusion

HemoHIM may be a beneficial supplement during cisplatin chemotherapy for enhancing the anti-tumor efficacy and reducing the toxicity of cisplatin.

Target specificity and off-target effects as determinants of cancer drug efficacy

Targeted therapeutics are aimed to hit one or a few key cellular targets. Agents that target single signaling molecules (such as EGFR and IGF-R1) often show limited clinical activities, at least in the major groups of solid tumors. Nevertheless, some signaling inhibitors are effective in the treatment of previously difficult-to-treat diseases such as renal carcinoma. Similarly, these drugs inhibit multiple kinases and/or may display off-target activities. Inhibition of cellular targets such as the proteasome, heat-shock protein 90, and histone deacetylase induces complex cellular effects, and agents that inhibit these targets show promising clinical activities. Clinically effective targeted agents are therefore reminiscent of conventional agents such as cisplatin and doxorubicin, which are known to have several cellular targets. It is becoming increasingly clear that a comprehensive understanding of the spectrum of effects exerted by an anticancer agent is fundamental for understanding its efficacy and toxicity profile.

Renal cell apoptosis induced by nephrotoxic drugs: cellular and molecular mechanisms and potential approaches to modulation

Apoptosis plays a central role not only in the physiological processes of kidney growth and remodeling, but also in various human renal diseases and drug-induced nephrotoxicity. We present in a synthetic fashion the main molecular and cellular pathways leading to drug-induced apoptosis in kidney and the mechanisms regulating it. We illustrate them using three main nephrotoxic drugs (cisplatin, gentamicin, and cyclosporine A). We discuss the main regulators and effectors that have emerged as key targets for the design of therapeutic strategies. Novel approaches using gene therapy, antisense strategies, recombinant proteins, or compounds obtained from both classical organic and combinatorial chemistry are examined. Finally, key issues that need to be addressed for the success of apoptosis-based therapies are underlined.

Effects of the licorice extract against tumor growth and cisplatin-induced toxicity in a mouse xenograft model of colon cancer

Cisplatin is one of the most effective chemotherapeutic agents and plays a major role in the treatment of a variety of human solid tumors. However, its toxicity limits the clinical use. Recently, the administration of antioxidants has been suggested to protect against cisplatin-induced nephrotoxicity. The present study was designed to estimate the antitumor activity of the licorice extract alone and in combination with cisplatin, and its protective potential against cisplatin-induced toxicity in a mouse xenograft model. The administration of the licorice extract significantly inhibited tumor growth in BALB/C mice inoculated with CT-26 colon cancer cells. The combination of the licorice extract and cisplatin diminished the therapeutic efficacy of cisplatin but promoted considerably antitumor activity of the licorice extract. In mice with cisplatin treatment for 15 d, the serum levels of blood urea nitrogen and creatinine remarkably were increased by kidney damage, and the serum alanine aminotransferase and aspartate aminotransferase levels were elevated by liver damage. The administration of the licorice extract plus cisplatin recovered these functional indices in the kidney and liver to almost the control levels. In addition, the administration of the licorice extract significantly reduced the cisplatin-induced oxidative stress. Taken together, the administration of the licorice extract inhibits the growth of mouse colon carcinoma without any adverse effects, and reduces the cisplatin-induced toxicity. Therefore, the licorice extract may be a candidate for an anticancer and chemopreventive agent. However, cancer patients with cisplatin therapy should avoid the supplementation of the licorice extract.

Simvastatin attenuates cisplatin-induced kidney and liver damage in rats

Statins have anti-inflammatory effects that are not directly related to their cholesterol-lowering activity. This study aimed to investigate the effect of simvastatin on the extent of tissue damage in cisplatin-induced nephrotoxicity and hepatotoxicity. The rats received a single intravenous injection of 2.5mgkg(-1) cisplatin. Other groups received either simvastatin (1mgkg(-1)) or the vehicle (ethanol:saline) intraperitoneally for 10 days beginning 5 days prior to cisplatin injection. All animals were decapitated 5 days after cisplatin administration. Trunk blood was collected and analyzed for blood urea nitrogen (BUN), creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), albumin, and total bilirubin levels. The urine samples were used for the calculation of creatinine clearance levels. The kidney and liver samples were stored for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content or were processed for histopathological examinations. Formation of reactive oxygen species in tissue samples was monitored by using chemiluminescence method. Simvastation reduced the extent of both kidney and liver damage and preserved both kidney and liver functions (p<0.01-0.001). Increase in liver MDA level with a concomitant reduction in GSH in the cisplatin group was attenuated by simvastatin treatment (p<0.05-0.01). Increase in tissue collagen content and chemiluminescence levels in the kidney and liver samples of the cisplatin group was also reversed by simvastatin (p<0.001). In conclusion, simvastatin is beneficial in cisplatin-induced kidney and liver dysfunction and organ damage in rats via prevention of lipid peroxidation and tissue fibrosis, preservation of antioxidant glutathione, and suppression of neutrophil infiltration.

Protective effect of cyclic AMP against cisplatin-induced nephrotoxicity

We reported earlier that reactive oxygen species are implicated in necrotic injury induced by a transient exposure of cultured renal tubular cells to a high concentration of cisplatin but not in apoptosis occurring after continuous exposure to a low concentration of cisplatin. We report here the protective effect of cyclic AMP against cisplatin-induced necrosis in cultured renal tubular cells as well as cisplatin-induced acute renal failure in rats. Several pharmacological agents that stimulate cyclic AMP signaling, including the nonhydrolyzable cyclic AMP analogue dibutyryl cyclic AMP, forskolin, 3-isobutyl-1-methylxanthine, and a prostacyclin analogue, beraprost, prevented cisplatin-induced cell injury in a protein kinase A-dependent manner. Cisplatin enhanced lipid peroxidation, decreased CuZn superoxide dismutase (SOD) while enhancing MnSOD activity, and increased cellular tumor necrosis factor-alpha (TNF-alpha) content. The elevation of TNF-alpha content and cell injury induced by cisplatin were attenuated by p38 mitogen-activated protein kinase (MAPK) inhibitors including SB203580 and PD169316. Indeed, cisplatin increased the number of phosphorylated p38 MAPK-like immunoreactive cells. These intracellular events were all reversed by antioxidants such as N-acetylcysteine (NAC) and glutathione or cyclic AMP analogues. The in vivo acute renal injury after cisplatin injection was associated with the elevation of renal TNF-alpha content. The cisplatin-induced renal injury and the increase in TNF-alpha content were reversed by NAC or beraprost. These findings suggest that cyclic AMP protects renal tubular cells against cisplatin-induced oxidative injury by obliterating reactive oxygen species and subsequent inhibition of TNF-alpha synthesis through blockade of p38 MAPK activation.

Relationship of Intracellular Calcium and Oxygen Radicals to Cisplatin-Related Renal Cell Injury

We investigated the involvement of reactive oxygen species (ROS) and intracellular calcium in nephrotoxicity related to an antitumor agent, cisplatin. In this study, we employed cultured renal epithelial cells (LLC-PK1). Cisplatin at 500 microM significantly increased the production of ROS 5 h and caused cell injury. This agent significantly increased the intracellular calcium level ([Ca2+]i) in a dose-dependent manner 1 h or more after exposure. DPPD (N,N'-diphenyl-p-phenylenediamine), an antioxidant, inhibited a cisplatin-related increase in active oxygen production and cell injury but did not inhibit an early increase in the [Ca2+]i level. An intracellular calcium-chelating compound BAPTA-AM (1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra(acetoxymethyl) ester) inhibited an increase in ROS production and cell injury induced by cisplatin. Furthermore, BAPTA-AM suppressed the rise of [Ca2+]i level in 1 h after exposure; however, an extracellular calcium chelator EGTA and a calcium antagonist nicardipine did not inhibit the rise in [Ca2+]i level in the early phase. An NADPH oxidase inhibitor inhibited a cisplatin-related increase in ROS production and cell disorder. These results suggest that cisplatin-related calcium release from the site of intracellular calcium storage in the early phase causes oxidative stress in renal tubular epithelial cells. Cisplatin may increase the intracellular production of ROS via NADPH oxidase.

Inhibition of tumor growth and prolonged survival of rats with intracranial gliomas following administration of clotrimazole

OBJECT

Clotrimazole, an imidazole derivative and inhibitor of cytochrome P-450, inhibits the proliferation of cancer cells by downregulating the movement of intracellular Ca++ and K+ and by interfering with the translation initiation process. Clotrimazole inhibits the proliferation of human glioblastoma multiforme cells; it induces morphological changes toward differentiation and blocks the cell cycle in the G1/G1 phase. In vitro, clotrimazole enhances the antitumor effect of cisplatin by inducing wild-type p53-mediated apoptosis. The authors examined the effect of clotrimazole on tumor growth, sensitivity to cisplatin, and survival of rats with intracranial gliomas.

METHODS

Cultured C6 and 9L glioma cells were exposed to clotrimazole, and cell growth was assessed using the 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide colorimetric assay. Clotrimazole produced a dose- and time-dependent inhibition of cell proliferation. The growth inhibitory effect of clotrimazole could not be overcome by exogenous stimulation with epidermal growth factor. Both C6 and 9L glioma cells were implanted into the rat brain and after 5 days, the animals were treated with a daily single dose of clotrimazole for 8 consecutive days. Clotrimazole treatment caused a significant inhibition of intracranial tumor growth. The survival of rats with 9L gliomas was analyzed after 10 days of treatment with clotrimazole, cisplatin, or a combination of clotrimazole and cisplatin. Rats treated with either drug displayed a significantly prolonged survival time; however, the combination treatment resulted only in an additional survival benefit.

CONCLUSIONS

Clotrimazole effectively inhibits cell proliferation and tumor growth, and prolongs survival of rats with intracranial gliomas. Clotrimazole may be considered a potential anticancer drug for treatment of intracranial gliomas.

Effects of lycopene against cisplatin-induced nephrotoxicity and oxidative stress in rats

The aim of this study was to investigate the effects of lycopene on cisplatin-induced nephrotoxicity and oxidative stress in rats. Adult male Sprague-Dawley rats were randomly divided into four groups. The control group (group 1) received physiological saline; animals in group 2 received only cisplatin; a 10 days of lycopene pre-treatment was applied to the animals in group 3 before administration of cisplatin; a 5 days of lycopene treatment was performed following administration of cisplatin for the animals in group 4. Cisplatin (7 mg/kg) was intraperitoneally injected as a single dose and lycopene (4 mg/kg) was administered by gavage in corn oil. Biochemical and histopathological methods were utilised for evaluation of the nephrotoxicity. The concentrations of creatinine, urea, Na+ and K+ in plasma and levels of malondialdehyde and reduced glutathione as well as glutathione peroxidase and catalase activities were determined in kidney tissue. Administration of cisplatin to rats induced a marked renal failure, characterized with a significant increase in plasma creatinine and urea concentrations. Na+ and K+ levels of rats received cisplatin alone were not significantly different compared to control group, but they had higher kidney malondialdehyde, and lower reduce glutathione concentrations, glutathione peroxidase and catalase activities. Lycopene administration produced amelioration in biochemical indices of nephrotoxicity in both plasma and kidney tissues when compared to group 2; pre-treatment with lycopene being more effective. Results from this study indicate that the novel natural antioxidant lycopene might have protective effect against cisplatin-induced nephrotoxicity and oxidative stress in rat.

Protective role of lycopene on cisplatin-induced changes in sperm characteristics, testicular damage and oxidative stress in rats

The aim of this study was to investigate the possible protective role of lycopene on cisplatin (CP)-induced spermiotoxicity using quantitative, biochemical and histopathological approaches. Adult male Sprague-Dawley rats were randomly divided into four groups. The control group received physiological saline; animals in cisplatin group received only cisplatin; pre-treatment group received a 10-day of lycopene before administration of cisplatin while animals in post-treatment group received a 5-day of lycopene following administration of cisplatin. Cisplatin (7 mg kg(-1)) was intraperitoneally (i.p.) injected as a single dose and lycopene (4 mg kg(-1)) was administered by gavage in corn oil. Traits of reproductive organs; sperm characteristics, testicular histological findings, plasma testosterone levels and the testicular tissue oxidative status were determined. Administration of cisplatin to rats decreased sperm concentration (p < 0.05) and sperm motility (p < 0.001), increased total abnormal sperm rates (p < 0.05) as compared with the control group. While a marked normalization was achieved only in sperm concentration with lycopene in pre-treatment group, significant normalizations were achieved in the sperm concentration, sperm motility, total abnormal sperm rates in post-treatment group. No significant differences in levels of testosterone were observed among all groups. An increase in testes malondialdehyde concentrations (p < 0.05) and glutathione peroxidase activities (p < 0.001) were detected while significant decreases in glutathione levels (p < 0.001) in cisplatin alone group when compared to control group. While pre-treatment with lycopene restoring only malondialdehyde concentrations, its post-treatment caused normalization in both malondialdehyde and glutathione levels when compared with the cisplatin alone group. On the other hand, significant increases were determined in GSH-Px activities in all experimental groups when compared with the control group. Although the mechanism is not clear, the results from this experimental study suggest that the lycopene have a possible protective effect against cisplatin-induced spermiotoxicity, effect of giving lycopene after cisplatin being superior to the giving it before cisplatin.

Antioxidant activity of DHC-1, an herbal formulation, in experimentally-induced cardiac and renal damage

DHC-1, an herbal formulation derived from the popular plants Bacopa monniera, Emblica officinalis, Glycyrrhiza glabra, Mangifera indica and Syzygium aromaticum was studied for its antioxidant activity. The protective effect of DHC-1 in isoproterenol-induced myocardial infarction and cisplatin-induced renal damage were studied. A significant reduction in the serum markers of heart and kidney damage and the extent of lipid peroxidation with a concomitant increase in the enzymatic (SOD and CAT) and non-enzymatic antioxidants (reduced glutathione) were observed in DHC-1 pretreated animals compared with the isoproterenol or cisplatin alone treated animals. Thus it can be concluded that DHC-1 possesses a protective effect against both damaged heart and kidneys in rats. This beneficial effect may be attributed, at least in part, to its antioxidant activity.

Prevention of Cisplatin Ototoxicity Using Transtympanic N-Acetylcysteine and Lactate

HYPOTHESIS

Transtympanic administration of the antioxidant N-acetylcysteine or lactated Ringer's solution onto the round window membrane will prevent cisplatin ototoxicity in the guinea pig model.

BACKGROUND

Cochlear ototoxicity is a well-known side effect of cisplatin administration, with the mechanism of injury thought to rest in oxidative damage to the outer hair cells. However, previous attempts at transtympanic antioxidant delivery have met with varied success. We present an effective method of counteracting cisplatin ototoxicity via the transtympanic application of lactated Ringer's solution or N-acetylcysteine.

METHODS

Baseline distortion product otoacoustic emission measurements were obtained. Intraperitoneal cisplatin was administered to a cumulative dose of 20 mg/kg. The middle ears were either untreated (control) or filled with normal saline (negative control), 2%N-acetylcysteine diluted in normal saline (treatment), or lactated Ringer's solution (treatment) via anterosuperior quadrant myringotomies. Posttreatment distortion product otoacoustic emissions were obtained.

RESULTS

Animals in the untreated control group and the negative control normal saline group demonstrated consistent obliteration of distortion product otoacoustic emissions. However, those receiving either lactated Ringer's solution or 2%N-acetylcysteine diluted in normal saline demonstrated significant preservation of distortion product otoacoustic emissions. The treatment regimen was well tolerated, with minimal animal loss.

CONCLUSION

We have demonstrated the efficacy of transtympanic lactated Ringer's solution and N-acetylcysteine in the prevention of cisplatin ototoxicity using a guinea pig model. The possible mechanisms for the high efficacy of lactated Ringer's solution are discussed in detail.

Protective Effect of Quercetin on the Evolution of Cisplatin-Induced Acute Tubular Necrosis

BACKGROUND

The mechanism of cisplatin-induced nephrotoxicity is unknown, but has been associated with renal lipid peroxidation. The bioflavonoid quercetin may be a potential alternative to reduce cisplatin-induced nephrotoxicity. The aim of this study was to evaluate the effect of quercetin on the evolution of cisplatin-induced acute tubular necrosis.

METHODS

One hundred and three male Wistar rats were injected with cisplatin (5 mg/kg, i.p.), 43 of them received quercetin (50 mg/kg, by gavage) before cisplatin injection. Blood and urine were collected 5 and 20 days after the injection for the determination of plasma creatinine, urine volume and osmolality. The kidneys were removed for the determination of renal malondialdehyde (MDA) and for histological and immunohistochemical studies. The renal expression of fibronectin, alpha-smooth muscle actin, vimentin, Jun N-terminal kinase, nuclear factor-kappaB, and macrophages during the evolution of the acute tubular necrosis induced by cisplatin and the histological changes observed in the kidneys were analyzed.

RESULTS

Cisplatin-treated rats presented a transitory increase in plasma creatinine levels, tubular cell necrosis and increased immunostaining for vimentin, alpha-SM-actin, fibronectin, ED1, NF-kappaB, and p-JNK in the renal cortex and outer medulla. These alterations were less intense in animals treated with quercetin.

CONCLUSION

Quercetin treatment attenuated the functional, histological and immunohistochemical alterations induced by cisplatin.

Role of poly(ADP-ribose)polymerase in cisplatin-induced injury in LLC-PK1 cells

Acute renal failure is a dose-limiting factor during cisplatin chemotherapy. We have previously shown in rats that the hydroxyl radical scavenger edaravone reverses cisplatin-induced in vivo renal damage. In the present study, the role of poly(ADP-ribose) polymerase (PARP) in cisplatin nephrotoxicity was investigated in porcine tubular cells LLC-PK1. Cell injury was elicited by transient exposure to 500 microM cisplatin for 1 h or continuous exposure to 30 microM cisplatin for 24 h. Various hydroxyl radical scavengers reversed cell damage in a transient but not permanent model. The cell injury seemed to be necrosis and apoptosis in transient and permanent models, respectively, as assessed by TUNEL method and Annexin V stain. PARP inhibitors such as 3-aminobenzamide and benzamide inhibited cell damage in transient but not permanent model. PARP-dependent cell injury was also observed after transient exposure to hydroxyl radical-generating solution. We demonstrated for the first time the activation of PARP in renal tubular cells by transient cisplatin exposure, as determined by immunofluorescent stain with anti-poly(ADP-ribose) antibody. Moreover, ATP was depleted by transient exposure to cisplatin or hydroxyl radical, both of which were reversed by PARP inhibitors. These findings suggest that hydroxyl radical generation followed by PARP activation contributes to the necrotic cell injury caused by a transient exposure to cisplatin.

Protection against cisplatin-induced nephrotoxicity by Cu(II)2(3,5-diisopropylsalicylate)4

The ability of Cu(II)(2)(3,5-diisopropylsalicylate)(4), CuDIPS, which exhibits superoxide dismutase (SOD)-like activity, to prevent cisplatin-induced nephrotoxicity was examined in rats. Rats were divided into four groups and treated as follows: (i) vehicle control; (ii) cisplatin (16 mg/kg, intraperitoneally); (iii) CuDIPS (10 mg/kg, intraperitoneally); and (iv) cisplatin plus CuDIPS. Rats were sacrificed 3 days post-treatment. Cisplatin alone resulted in significantly increased plasma creatinine and urea. Administration of 10 mg/kg CuDIPS prevented the cisplatin-induced elevation of plasma creatinine and urea and protected against kidney damage. Relative to controls, rats that received cisplatin treatment displayed a decrease of reduced glutathione (GSH) and elevated platinum and thiobarbituric acid reactive substances (TBARS) levels in the kidney. In comparison with controls, activities of antioxidant enzymes (SOD, CAT, GSH-Px and GSH-Rd) were also reduced in the kidney of rats treated with cisplatin. Administration of 10 mg/kg CuDIPS prevented cisplatin-induced alterations in renal platinum, GSH, TBARS, and antioxidant enzyme activities. This study suggests that the protection offered by CuDIPS against cisplatin-induced nephrotoxicity is partly related to maintenance of renal antioxidant systems.