Evidence against protective role of sex hormone estrogen in Cisplatin-induced nephrotoxicity in ovarectomized rat model

Tumor necrosis factor-alpha antibody labeled-polyethylene glycol-coated nanoparticles: A mesenchymal stem cells-based drug delivery system in the rat model of cisplatin-induced nephrotoxicity

Background and Aim: A delivery system consisting of bone marrow mesenchymal stem cells (MSCs) loaded with polyethylene glycol (PEG) coated superparamagnetic iron oxide nanoparticles (SPIONs) was constructed to treat a rat model of cisplatin (Cis)-induced nephrotoxicity with 1/10 of the common dose of anti-tumor necrosis factor-alpha (TNF-α) antibodies (infliximab). Materials and Methods: Morphology, size, crystallinity, molecular structure, and magnetic properties of uncoated and PEG-coated SPIONs were analyzed. A delivery system consisting of MSCs containing infliximab-labeled PEG-coated SPIONs (Infliximab-PEG-SPIONs-MSCs) was generated and optimized before treatment. Fifty female Wistar rats were divided into five equal groups: Group 1: Untreated control; Group 2 (Cis): Rats were administered Cis through intraperitoneal (i.p.) injection (8 mg/kg) once a week for 4 weeks; Group 3 (Infliximab): Rats were injected once with infliximab (5 mg/kg), i.p. 3 days before Cis administration; Group 4 (Cis + MSCs): Rats were injected with Cis followed by an injection of 2 × 106 MSCs into the tail vein twice at a 1-week interval; and Group 5 (Cis + Infliximab (500 μg/kg)-PEG-SPIONs-MSCs): Rats were injected with the delivery system into the tail vein twice at a 1-week interval. Besides histological examination of the kidney, the Doppler ultrasound scanner was used to scan the kidney with the Gray-color-spectral mode. Results: In vivo, intra-renal iron uptake indicates the traffic of the delivery system from venous blood to renal tissues. Cis-induced nephrotoxicity resulted in a significant increase in TNF-α and malondialdehyde (MDA) (p < 0.05), bilirubin, creatinine, and uric acid (p < 0.01) levels compared with the untreated control group. The different treatments used in this study resulted in the amelioration of some renal parameters. However, TNF-α levels significantly decreased in Cis + Infliximab and Cis + MSCs (p < 0.05) groups. The serum levels of MDA significantly decreased in Cis + Infliximab (p < 0.05), Cis + MSCs (p < 0.05), and Cis + Infliximab-PEG-SPIONs-MSCs (p < 0.01). Furthermore, the serum activities of antioxidant enzymes were significantly elevated in the Cis + MSCs and Cis + Infliximab-PEG-SPIONs-MSCs groups (p < 0.05) compared to the Cis-induced nephrotoxicity rat model. Conclusion: With the support of the constructed MSCs-SPIONs infliximab delivery system, it will be possible to track and monitor cell homing after therapeutic application. This infliximab-loading system may help overcome some challenges regarding drug delivery to the target organ, optimize therapeutics' efficacy, and reduce the dose. The outcomes of the current study provide a better understanding of the potential of combining MSCs and antibodies-linked nanoparticles for the treatment of nephrotoxicity. However, further investigation is recommended using different types of other drugs. For new approaches development, we should evaluate whether existing toxicity analysis and risk evaluation strategies are reliable and enough for the variety and complexity of nanoparticles.

Sex Difference in Cisplatin-Induced Nephrotoxicity: Laboratory and Clinical Findings

Cisplatin (CP) as the most important anticancer drug has limited usage due to a lot of side effects such as nephrotoxicity. Additionally, nephrotoxicity is gender/sex-related. There is a variety of experimental studies in association with sex and CP-induced nephrotoxicity. Some studies have reported that female sex is resistant than male sex due to greater antioxidant defense and protective effects of estrogen in females. Other studies have indicated that males are less vulnerable than females due to CP high clearance. Also, various supplementations have revealed conflicting effects in males and females. It is uncovered that sex hormones have determinant roles on the conflicting effects. Some supplements could improve CP-induced nephrotoxicity, but several supplements intensified CP-induced nephrotoxicity, especially in female sex. On the other hand, major clinical studies introduced female gender as a risk factor of CP-induced nephrotoxicity. Although, rare studies evaluated the effect of various supplemental compounds on CP-induced nephrotoxicity in patients underwent CP therapy. Therefore, it requires further investigations to clarify the controversial subject of gender/sex and CP-induced nephrotoxicity in both clinic and laboratory.

Syntheses, crystal structure, thermal behavior, and anti-tumor activity of three ternary metal complexes with 2-chloro-5-nitrobenzoic acid and heterocyclic compounds

Three complexes, namely complex (1), complex (2), and complex (3), were synthesized and characterized by X-ray diffraction, thermogravimetric study, and elemental study. Complex (1) comprises discrete binuclear clusters, where two oxygen atoms of 2-chloro-5-nitrobenzoic acid bridge the two copper atoms. Complex (2) is a six-coordination structure consisting of four nitrogen atoms and two oxygen atoms in 2-chloro-5-nitrobenzoic acid and 1,10-phenanthroline to furnish a twisted octahedron. Complex (3) is a six-coordination structure consisting of four oxygen atoms and two nitrogen atoms from the 2-chloro-5-nitrobenzoic acid, methanol, and 2,2′-dipyridyl to furnish a distorted octahedral geometry. Metal complexes’ anti-tumor activity was also investigated by the MTT assay. Of the complexes tested, complex (1) could induce apoptosis in these A549 lung cancer and Caco-2 colon adenocarcinoma cells and complex (2) could induce apoptosis in Caco-2 colon adenocarcinoma cells. CCDC for complex (1) was 1543354, CCDC for complex (2) was 1546991, and CCDC for complex (3) was 1543417.

The Prevention of Cisplatin-Induced Nephrotoxicity: A General Consensus Statement of a Group of Oncologist-Hematologists, Adult and Pediatric Nephrologists, Radiation Oncologists, Clinical Pathologists, Clinical Pharmacologists, and Renal Physiologists on Cisplatin Therapy in Cancer Patients

Backgrounds

Most of the cancer patients with solid tumor are subjected to chemotherapy with cisplatin (CP) in clinic. However, the most side effect of CP is nephrotoxicity, which limits the treatment. The aim of study was to develop a general consensus statement for CP therapy in clinic to limit the drug-induced nephrotoxicity.

Methods

A total of 30 oncologist-hematologists, adult and pediatric nephrologists, radiation oncologists, clinical pathologist clinical pharmacologist, and renal physiologist participated in a workshop, and in order to reduce the incidence of CP-induced nephrotoxicity, a general consensus was developed.

Results

The developed general consensus was focused on some items such as age, sex, female hormone, nonsteroidal anti-inflammatory drugs (NSAID), renin-angiotensin system inhibitor drugs, glomerular filtration rate, hydration methods, contrasts, antioxidants, dextrose, and magnesium.

Conclusion

The agreement between participants for CP therapy in clinic was achieved, and this general consensus was announced to be implemented in the hospitals.

Hydration with Mannitol and Dextrose May Promote Cisplatin-Induced Nephrotoxicity: Test of Five Protocols of Hydration during Cisplatin Therapy in Rat Models

Backgrounds

Cisplatin (CP) still is a novel choice for solid tumor therapy, but it is accompanied with the side effect of nephrotoxicity. Hydration may reduce the risk of CP-induced nephrotoxicity, while the issue is still challenging. In this study, five types of hydration protocols including saline, mannitol, dextrose saline, saline plus furosemide, and saline plus mannitol were examined in both sexes of rats during CP therapy.

Methods

Seventy-six male and female Wistar rats in 14 groups of experiments were subjected to CP therapy, and five types of hydration protocols were implemented, and the induced nephrotoxicity was evaluated via biochemical markers, kidney function parameters, and pathology investigation.

Results

Male and female rats had different responses to hydration protocol types. The higher mortality rate was seen in female rats that received mannitol or dextrose hydration types. In addition, the serum levels of blood urea nitrogen (BUN) and creatinine (Cr) and sodium excretion fraction (ENa%) increased and the clearance of Cr (ClCr) decreased significantly (P < 0.05) in female rats hydrated with saline plus furosemide or mannitol plus saline-treated groups. The worsened condition in male rats is observed in the mannitol hydration group with a significant decrease of ClCr and significant increase of serum BUN and Cr and ENa% (P < 0.05). The higher kidney tissue damage score (KTDS) in the mentioned groups verified the findings.

Conclusion

Hydration with mannitol or dextrose promotes the risk of nephrotoxicity during CP therapy with more intensity on the female.

Sex Differences in Renal Function: Participation of Gonadal Hormones and Prolactin

Kidney pathophysiology is influenced by gender. Evidence suggests that kidney damage is more severe in males than in females and that sexual hormones contribute to this. Elevated prolactin concentration is common in renal impairment patients and is associated with an unfavorable prognosis. However, PRL is involved in the osmoregulatory process and promotes endothelial proliferation, dilatation, and permeability in blood vessels. Several proteinases cleavage its structure, forming vasoinhibins. These fragments have antagonistic PRL effects on endothelium and might be associated with renal endothelial dysfunction, but its role in the kidneys has not been enough investigated. Therefore, the purpose of this review is to describe the influence of sexual dimorphism and gonadal hormones on kidney damage, emphasizing the role of the hormone prolactin and its cleavage products, the vasoinhibins.

High-intensity interval training is more effective than continuous training to reduce inflammation markers in female rats with cisplatin nephrotoxicity

AIMS

Cisplatin (CP) is an antineoplastic widely used in the treatment of various solid tumors, however, its clinical application is limited by nephrotoxicity. Here, we compared the impact of preconditioning with high-intensity interval training (HIIT) with continuous training of low (LIT) and moderate (MIT) intensity on innate immunity markers in female rats with CP-induced acute kidney injury.

MATERIALS AND METHODS

The rats were divided into five groups (n = 7): saline control and sedentary (C + S); CP and sedentary (CP + S); CP and LIT (CP + LIT); CP and MIT (CP + MIT) and CP and HIIT (CP + HIIT). The training intensity was determined by a maximum running test. At the end of training, the rats received a single dose of CP (5 mg/kg), and 7 days later they were euthanized. We evaluated renal function parameters (serum creatinine, glomerular filtration rate and proteinuria), renal structure, macrophage tissue infiltration, immunolocalization of nuclear transcription factor kappa B (NF-κB), renal levels of tumor necrosis factor-alpha (TNF-α), interleukin 1β (IL-1β), and interleukin 6 (IL-6), and gene expression of monocyte chemoattractant protein-1 (MCP-1), toll-like receptor 4 (TLR4), and NF-κB in renal tissue.

KEY FINDINGS

Although both MIT and HIIT attenuated the degree of renal injury, only the HIIT prevented changes in renal function. The three training protocols mitigated the increase in expression of all inflammatory markers, however, this effect was more pronounced in HIIT.

SIGNIFICANCE

All training protocols promoted renoprotective actions, but HIIT was more effective in mitigating CP-induced acute kidney injury, in part by modulation of important markers of the innate immune response.

Potential role of estradiol in ovariectomy-induced derangement of renal endocrine functions

Menopause is an important physiological event associated with structural and functional changes in the kidneys. An animal model of bilateral ovariectomy was used to study the effects of estrogen depletion, replacement and antiestrogen on renal structure and endocrine function. Sixty female rats were divided into six groups; group I was the control group, the remaining five groups underwent ovariectomy: group II received no treatment. The other groups received estradiol in group III, tamoxifen in group IV, estradiol followed by tamoxifen in group V and tamoxifen followed by estradiol in group VI. Serum creatinine, blood urea nitrogen, and endocrine functions of kidney were measured. Tissue samples were examined both microscopically for beta estrogen receptors and ultrastructurally for cell changes. Groups II, IV & VI showed a significant increase in creatinine, blood urea nitrogen, renal malondialdehyde, renal erythropoietin, plasma renin and plasma prostaglandin E2 and a significant decrease in renal antioxidants and serum vitamin D3. Groups III &V had a significant decrease in creatinine, blood urea nitrogen, renal malondialdehyde and renal erythropoietin with an increase in renal antioxidants, plasma prostaglandin E2 and serum vitamin D3. Histopathological and ultrastructural examinations revealed atrophic tubular changes in group II. The changes were less marked in groups III &V and more extensive in groups IV & VI. Estrogen receptor beta staining showed progressively increased expression in the absence of estrogen. Structural and most endocrine functions of the kidney were significantly affected by estradiol deficiency. Estradiol replacement exhibited a protective effect on renal tissue and endocrine functions.

Squalene attenuates the oxidative stress and activates AKT/mTOR pathway against cisplatin-induced kidney damage in mice

The clinical use of cisplatin, which is a first-line anticancer agent, is highly restricted due to its adverse effects on kidneys that lead to nephrotoxicity. Therefore, some potential reno-protective substances have been used in combination with cisplatin to cope with nephrotoxicity. Due to its high antitumor activity and oxygen-carrying capacity, we investigated the molecular effects of squalene against cisplatin-induced oxidative stress and kidney damage in mice. Single dose of cisplatin (7 mg/kg) was given to male Balb/c mice. Squalene (100 mg/kg/day) was administered orogastrically to mice for 10 days. Following sacrification, molecular alterations were investigated as analysis of the levels of oxidative stress index (OSI), inflammatory cytokines and cell survival-related proteins in addition to histopathological examinations in mice kidney tissue. The level OSI and Interferon-gamma (IFN-γ) decreased in the cisplatin and squalene cotreated mice compared to cisplatin-treated mice. Squalene treatment also increased the activation of protein kinase B (AKT). Furthermore, cisplatin-induced inactivation of mammalian target of rapamycin (mTOR) and histopathological damages were reversed by squalene. It may be suggested that squalene ameliorated the cisplatin-induced histopathological damages in the kidney through activation of AKT/mTOR signaling pathway by regulating the balance of the redox system due to its antioxidative effect.

Cisplatin-Induced Rodent Model of Kidney Injury: Characteristics and Challenges

Cisplatin is an antitumor drug used in the treatment of a wide variety of malignancies. However, its primary dose-limiting side effect is kidney injury, which is a major clinical concern. To help understand mechanisms involved in the development of kidney injury, cisplatin rodent model has been developed. Given the complex pathogenesis of kidney injury, which involves both local events in the kidney and interconnected and interdependent systemic effects in the body, cisplatin rodent model is indispensable in the investigation of underlying mechanisms and potential treatment strategies of both acute and chronic kidney injury. Cisplatin rodent model is well appreciated and widely used model due to its simplicity. It has many similarities to human cisplatin nephrotoxicity, which are mentioned in the paper. In spite of its simplicity and wide applicability, there are also traps that need to be taken into account when using cisplatin model. The present paper is aimed at giving a concise insight into the complex characteristics of cisplatin rodent model and heterogeneity of cisplatin dosage regimens as well as outlining factors that can severely influence the outcome of the model and the study. Challenges for future research are also mentioned.

Cisplatin Alters Sodium Excretion and Renal Clearance in Rats: Gender and Drug Dose Related

Background:

Nephrotoxicity is one of the side effects of cisplatin (CP) therapy which is gender related. CP disturbs renal function through glomerular filtration rate and electrolytes transport disturbances. This study was designed to compare some markers related to renal function in two protocols of CP treatment in rats.

Materials and Methods:

Male and female rats were subjected to receive single (treat 1; 7.5 mg/kg) and continues doses (treat 2; 3 mg/kg/day for 5 days) of CP, and the measurements were compared with control animals.

Results:

The serum level of blood urea nitrogen (BUN) and creatinine (Cr), and Cr-clearance, kidney tissue damage score, kidney weight, body weight change, and Na excretion was altered significantly (P < 0.05) in animals treated with continuous dose of CP (treat 2), while alteration of BUN and Cr was gender related. The kidney levels of malondialdehyde and nitrite were significantly different between male and female in two protocols of treatments.

Conclusion:

Renal function after CP therapy alters in rats’ gender dependently, and it is related to protocol of treatment.

Parp1 protects against Aag-dependent alkylation-induced nephrotoxicity in a sex-dependent manner

Nephrotoxicity is a common toxic side-effect of chemotherapeutic alkylating agents. Although the base excision repair (BER) pathway is essential in repairing DNA alkylation damage, under certain conditions the initiation of BER produces toxic repair intermediates that damage healthy tissues. We have shown that the alkyladenine DNA glycosylase, Aag (a.k.a. Mpg), an enzyme that initiates BER, mediates alkylation-induced whole-animal lethality and cytotoxicity in the pancreas, spleen, retina, and cerebellum, but not in the kidney. Cytotoxicity in both wild-type and Aag-transgenic mice (AagTg) was abrogated in the absence of Poly(ADP-ribose) polymerase-1 (Parp1). Here we report that Parp1-deficient mice expressing increased Aag (AagTg/Parp1^−/−) develop sex-dependent kidney failure upon exposure to the alkylating agent, methyl methanesulfonate (MMS), and suffer increased whole-animal lethality compared to AagTg and wild-type mice. Macroscopic, histological, electron microscopic and immunohistochemical analyses revealed morphological kidney damage including dilated tubules, proteinaceous casts, vacuolation, collapse of the glomerular tuft, and deterioration of podocyte structure. Moreover, mice exhibited clinical signs of kidney disease indicating functional damage, including elevated blood nitrogen urea and creatinine, hypoproteinemia and proteinuria. Pharmacological Parp inhibition in AagTg mice also resulted in sensitivity to MMS-induced nephrotoxicity. These findings provide in vivo evidence that Parp1 modulates Aag-dependent MMS-induced nephrotoxicity in a sex-dependent manner and highlight the critical roles that Aag-initiated BER and Parp1 may play in determining the side-effects of chemotherapeutic alkylating agents.

Cisplatin Nephrotoxicity Might Have a Sex Difference. An analysis Based on Women's Sex Hormone Changes

Background: A sex difference in cisplatin-induced nephrotoxicity (CIN) has been reported in human and animal studies. We examined in humans whether it is associated with sex-hormone changes. Methods: In this retrospective nationwide cohort study, we used Taiwan's National Health Insurance Research Database (NHIRD) to identify patients with a history of malignancy and cisplatin treatment. Patients diagnosed with kidney disease before cisplatin treatment and those with sex-organ malignancies were excluded. A diagnosis of kidney disease within 90 days after the first administration of cisplatin was the study outcome. Risk factors were estimated using a Cox regression model. Subgroup analyses were performed based on different women's estrogen levels in phases of childbearing, perimenopause, and postmenopause. Results: A retrospective analysis of the records of 3973 men (mean age: 56.15 ± 12.85 years) and 1154 women (mean age: 56.31 ± 12.40 years) showed that 1468 (36.95%) men and 451 (39.08%) women had a new diagnosis of kidney disease. The risk factors were being > 55 years old, a high comorbidity score, and a history of aminoglycoside treatment. Only postmenopausal women had a significantly higher risk of kidney injury (hazard ratio: 1.28; 95% CI: 1.02-1.61) than did men. Conclusions: Perimenopausal women have a significantly higher risk of CIN than do men, which might be explained by women's higher levels of estrogen. Additional studies on the underlying mechanisms of the sex difference of CIN are needed.

Effect of Short Hydration on Cisplatin-Induced Nephrotoxicity in Cancer Patients: A Retrospective Study

Background: The aim of this study was to evaluate the protective role of short hydration against nephrotoxicity induced by cisplatin (CDDP). Materials and Methods: Twenty-two patients (13 men and 9 women) under CDDP therapy were enrolled in this retrospective study between 2009 and 2014. The CDDP was given in 500 ml of isotonic solution, and before and after CDDP administration, the patients received 10mEq potassium chloride15% and 1gr magnesium sulfate in 1000 ml isotonic saline. Renal parameters were evaluated on the first day of each cycle of CDDP therapy. Results: Median cumulative CDDP dose was 465 mg/m². Based on renal parameters, the prevalence of CDDP-induced nephrotoxicity (CIN) was 22.7%, while no hypokalemia and hypomagnesemia were observed. Conclusion: Short hydration accompanied with potassium chloride and magnesium sulfate may decrease the risk of CIN.

Unique sex- and age-dependent effects in protective pathways in acute kidney injury

Sex and age influence susceptibility to acute kidney injury (AKI), with young females exhibiting lowest incidence. In these studies, we investigated mechanisms which may underlie the sex/age-based dissimilarities. Cisplatin (Cp)-induced AKI resulted in morphological evidence of injury in all groups. A minimal rise in plasma creatinine (PCr) was seen in Young Females, whereas in Aged Females, PCr rose precipitously. Relative to Young Males, Aged Males showed significantly, but temporally, comparably elevated PCr. Notably, Aged Females showed significantly greater mortality, whereas Young Females exhibited none. Tissue KIM-1 and plasma NGAL were significantly lower in Young Females than all others. IGFBP7 levels were modestly increased in both Young groups. IGFBP7 levels in Aged Females were significantly elevated at baseline relative to Aged Males, and increased linearly through day 3, when these levels were comparable in both Aged groups. Plasma cytokine levels similarly showed a pattern of protective effects preferentially in Young Females. Expression of the drug transporter MATE2 did not explain the sex/age distinctions. Heme oxygenase-1 (HO-1) levels (~28-kDa species) showed elevation at day 1 in all groups with highest levels seen in Young Males. Exclusively in Young Females, these levels returned to baseline on day 3, suggestive of a more efficient recovery. In aggregate, we demonstrate, for the first time, a distinctive pattern of response to AKI in Young Females relative to males which appears to be significantly altered in aging. These distinctions may offer novel targets to exploit therapeutically in both females and males in the treatment of AKI.

Age and Gender Related Renal Side Effects of Cisplatin in Animal Model

Backgrounds:

Cisplatin (CDDP) is a choice of anti-cancer drug for cancer chemotherapy with serious side effects such as nephrotoxicity. It seems that age is an important factor influencing the side effects of CDDP. This study was designed to determine the role of age and gender simultaneously in CDDP induced renal toxicity.

Methods:

40 Wistar male and female rats were assigned as 6 groups in 3 different age categories (10, 16, and 20 weeks old). The single dose of CDDP (7.5 mg/kg, ip) was administrated, and a week later measurements were performed.

Results:

Body weight changes in male (not in female) animals aged 16 and 20 weeks were more than 10 weeks old animals (P<0.05). In male rats, the serum levels of creatinine (Cr) and blood urea nitrogen (BUN), and Cr-clearance in aged 10 weeks, normalized kidney weight (KW) in aged 20 weeks, and serum nitrite, aspartate aminotransferase (AST) and malondialdehyde (MDA) levels and kidney tissue damage score (KTDS) in rats aged 16 weeks were significantly altered (P<0.05). Gender difference in serum level of Cr, BUN and nitrite, and Cr-clearance were observed in animals aged10 weeks (P<0.05).

Conclusion:

The side effects of CDDP are gender depended, and may be different at various ages.

Cisplatin-Induced Nephrotoxicity; Protective Supplements and Gender Differences

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

Time course of cisplatin-induced nephrotoxicity and hepatotoxicity

Background:

One of the main therapeutic limitations of cisplatin (CP) is nephrotoxicity which is time-dependent.

Objectives:

The purpose of this study was to determine the optimal timing for initiation of CP toxicity.

Materials and Methods:

Sixty male and female Wistar rats were randomly divided into five groups. All the animals in groups 2-5 received single dose of CP (10 mg/kg; i.p.), and were evaluated 25, 50, 75, and 100 hours after CP administration. Group 1 as an untreated group did not receive any agent and was considered as time zero.

Results:

The data indicated time-dependent progression of kidney and hepatic toxicity due to CP administration. Histological examination showed increase in kidney tissue damage score (KTDS) at hour 25, which peaked 75-100 hours after CP administration. Significant body weight loss and reduction of alkaline phosphatase (ALP) 50 hours after CP injection were observed. Blood urea nitrogen (BUN), creatinine (Cr), and serum nitrite increased significantly 75 hours after CP injection. Also, enhancement of kidney and testis weights, and alkaline aspartate aminotransferase (AST) level; and reduction of alanine aminotransferase (ALT) level and uterus weight occurred significantly 100 hours after the injection, while kidney malondialdehyde level enhanced significantly 75 hours after CP administration.

Conclusions:

These findings suggest that the CP-induced nephrotoxicity started to develop almost 3 days after administration of the drug in rats. CP surprisingly reduced the serum levels ALP and ALT while AST increased 100 hours after CP injection. CP-induced nephrotoxicity and hepatotoxicity are time-dependent, and the related biomarkers may alter by different trends.

Hormone replacement therapy reduces lipid oxidation directly at the arterial wall: A possible link to estrogens' cardioprotective effect through atherosclerosis prevention

Background:

The first step in atherosclerosis formation is the ingurgitation of an oxidized low-density lipid (LDL) molecule by a macrophage which then turns into a foam cell within the vascular wall and initiates a cascade of inflammatory responses. Could it be that the potential cardioprotective effect observed in women receiving hormone replacement therapy (HRT) is modulated by estrogen's capacity to decrease LDL oxidation in the vascular wall and thus decrease atherosclerotic foam cells?

Materials and Methods:

Thirty-four adult female Wistar rats were divided into three groups. All were double oophorectomized. After recovery, Group 1 received Estradiol Valerate subcutaneous (SC) (2.5 mg/kg/week), Group 2 Estradiol Valerate SC (2.5 mg/kg/week) + Progesterone SC (10 mg/kg/48 h), and Group 3 Placebo SC. After 10 weeks, all rats were sacrificed and a vascular dissection performed. Malondialdehyde (MDA) was measured directly on the vascular extract to determine lipid oxidative levels and HRTs' effect. Renal and hepatic tissue was also studied. Total antioxidant status (TAS) was measured to determine overall oxidative behavior.

Results:

Vascular MDA levels for Group 1 = 80.80 (±16.8) μmol/ml/g, Group 2 = 107.69 (±24.9) μmol/ml/g, and Group 3 = 140.96 (±32.4) μmol/ml/g. ANOVA (P < 0.05), with a post hoc Bonferroni corrective t-test, showed that both Group 1 and 2 have statistically significant lower levels of MDA than Group 3. Renal tissue showed less oxidative damage in the HRT groups, while hepatic tissue showed an inverse behavior with less lipid oxidation in the placebo group. TAS decreased with oophorectomy in all groups but decreased less in both groups that received HRT compared to placebo (P < 0.05).

Conclusion:

HRT significantly reduces lipid oxidation directly in the arterial wall.

Gamma-aminobutyric acid aggravates nephrotoxicity induced by cisplatin in female rats

Introduction: Cisplatin (CP) is a major antineoplastic drug for treatment of solid tumors. CP-induced nephrotoxicity may be gender-related. This is while gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in the central nervous system that has renoprotective impacts on acute renal injury.

Objectives: This study was designed to investigate the protective role of GABA against CP-induced nephrotoxicity in male and female rats.

Materials and Methods: Sixty Wistar male and female rats were used in eight experimental groups. Both genders received GABA (50 μg/kg/day; i. p.) for 14 days and CP (2.5 mg/kg/day; i. p.) was added from day 8 to the end of the study, and they were compared with the control groups. At the end of the study, all animals were sacrificed and the serum levels of blood urea nitrogen (BUN), creatinine (Cr), nitrite, malondialdehyde (MDA), and magnesium (Mg) were measured. The kidney tissue damage was also determined via staining.

Results: CP significantly increased the serum levels of Cr and BUN, kidney weight, and kidney tissue damage score in both genders (P<0.05). GABA did not attenuate these markers in males; even these biomarkers were intensified in females. Serum level of Mg, and testis and uterus weights did not alter in the groups. However, the groups were significantly different in terms of nitrite and MDA levels.

Conclusion: It seems that GABA did not improve nephrotoxicity induced by CP-treated rats, and it exacerbated renal damage in female rats.

Nephroprotective effect of estrogen and progesterone combination on cisplatin-induced nephrotoxicity in ovariectomized female rats

Recently, we reported that estrogen (Es) has no beneficial effect on cisplatin (CP)-induced nephrotoxicity, but the role of progesterone (Pr) and the combination of Es and Pr are not yet well-defined. In this study, we investigated the protective role of Pr, and co-administration of Es/Pr on CP-induced nephrotoxicity. Eighty-six ovariectomized female Wistar rats were divided into 13 groups, and the experiments were performed in two phases. In Phase I, Groups 1-4 received 2, 5, 10, and 25 mg/kg, IM Pr dissolved in sesame oil every 5 days for four doses. Groups 5-8 had the same treatment regimen as Groups 1-4, but after the third injection the animals also received continuous dose of CP (2.5 mg/kg/day, i.p.) for 8 days. Group 9, as the positive control group, received sesame oil instead of Pr plus CP. Group 10, as the negative control group, received sesame oil instead of Pr. After the most effective dose of Pr was determined in Phase I, Groups 11-13 in Phase II received 10 mg/kg Pr plus either 0.25, 0.5, or 1 mg/kg, IM estradiol valerate every 5 days for four doses. After the third injection, they also received a continuous dose of CP for 8 days. The levels of blood urea nitrogen (BUN) and creatinine (Cr), kidney tissue damage score (KTDS), and kidney weight (KW) increased and body weight (BW) decreased in the positive control group (P < 0.05). Administration of Pr (10 mg/kg) plus CP decreased KTDS and BW loss and KW. Co-administration of ES/Pr at specific doses improved Cr, BUN, and KTDS; and resulted in reduced CP-induced nephrotoxicity. The results obtained suggest that the beneficial effect of Pr on CP-induced nephrotoxicity is dose-dependent. In addition, combination of Es/Pr with a specific dose decreased CP-induced nephrotoxicity.

Cisplatin-induced nephrotoxicity alters blood pressure response to angiotensin II administration in rats

Background:

Cisplatin (CP) is an effective chemotherapeutic drug used in the clinic, which is accompanied with nephrotoxicity. CP may also disturb hemodynamics of the circulation system. We have tested the role of CP in mean arterial pressure (MAP) response to graded angiotensin (Ang) II infusion in rats.

Materials and Methods:

Male and female rats were treated with CP (2.5 mg/kg/day) for a period of 1-week and compared with the vehicle-treated animals. The blood pressure response to Ang II (100–1000 ng/kg/min) was determined under the anesthesia condition. Endothelial permeability of aorta was measured according to the Evans blue uptake. The kidney tissue was also subjected to histological investigation.

Results:

Significant increase in serum levels of blood urea nitrogen and creatinine and pathological findings in CP-treated rats verified CP-induced nephrotoxicity. Significant difference in percentage of change in MAP response to Ang II between male and female rats was detected in vehicle-treated groups (P < 0.05) while in CP-treated animals this response difference was not observed. The groups were not significantly different with regard to the endothelial permeability of aorta while the serum level of nitrite in male rats increased significantly following administration of CP (P < 0.05).

Conclusion:

It seems the different response in percentage of change of MAP to graded Ang II infusion between male and female indicates the effect of CP on renin Ang system parameters.

Effect of enalapril in cisplatin-induced nephrotoxicity in rats; gender-related difference

Background:

The function of renin angiotensin system (RAS) is gender-related, and this system affects cisplatin (CP)-induced nephrotoxicity. In this study, we compared the effect of enalapril as an angiotensin-converting enzyme (ACE) inhibitor on CP-induced nephrotoxicity between male and female rats.

Materials and Methods:

Sixty-two adult male and female Wistar rats were divided into eight groups. Both genders received CP (2.5 mg/kg, i.p.) and enalapril (30 mg/kg, i.p.) for 7 days in compared with CP alone or enalapril alone or vehicle alone treated groups. At the end of the experiment, blood samples were obtained, and the kidney tissue was investigated for histopathological changes.

Results:

CP increased the serum levels of blood urea nitrogen and creatinine as well as kidney weight and kidney tissue damage score in both genders (P < 0.05). However, not only enalapril failed to ameliorate the aforementioned parameters in both genders, but also it intensified nephrotoxicity in females (P < 0.05). In addition, enalapril enhanced body weight loss induced by CP in females (P < 0.05). CP alone decreased kidney level of nitrite in both genders (P < 0.05) and enalapril could not reverse this decreasing. The combination of enalapril and CP significantly increased serum level of nitrite in females, but this was not observed in males (P < 0.05).

Conclusion:

Enalapril as an ACE inhibitor failed to ameliorate nephrotoxicity induced by CP in both male and female rats. In addition, enalapril aggravated CP-induced nephrotoxicity in female possibly due to gender-dependent RAS response.

Gentamicin Induced Nephrotoxicity: The Role of Sex Hormones in Gonadectomized Male and Female Rats

Background. Gentamicin (GM) induced nephrotoxicity may be sex hormones related. The effects of sex hormones on GM induced nephrotoxicity in gonadectomized rats were investigated. Methods. Ovariectomized rats received 0.25, 0.5, or 1 mg/kg/week of estradiol (ES) alone or accompanied with 10 mg/kg/week of progesterone (Pro) for two weeks followed by GM (100 mg/kg/day) for 9 days. Castrated rats were also treated with 10, 50, or 100 mg/kg/week of testosterone (TS) for two weeks and then received GM. In addition, a single castrated group received 0.25 mg/kg/week of ES plus GM. Results. GM increased the serum levels of blood urea nitrogen (BUN) and creatinine (Cr) and kidney tissue damage score (KTDS) (P < 0.05). TS had no effect on the serum levels of BUN and Cr and KTDS, while low dose of ES intensified these parameters in male (P < 0.05). ES (0.5 mg/kg) without Pro ameliorated KTDS in female (P < 0.05) while ES (1 mg/kg) with or without Pro exacerbated the BUN values and Cr values, KTDS, and body weight loss (P < 0.05). Conclusion. ES (0.5 mg/kg) without Pro ameliorated kidney damage induced by GM in female while neither TS nor ES had beneficial effect on nephrotoxicity induced by GM in male, although ES aggravated it.

Exaggerated arsenic nephrotoxicity in female mice through estrogen-dependent impairments in the autophagic flux

Gender is one of the essential factors in the development of various diseases and poisoning. Therefore, we herein examined gender differences in sodium arsenite (NaAsO2)-induced acute renal dysfunction. When male and female BALB/c mice were subcutaneously injected with NaAsO2 (12.5mg/kg), serum and urinary markers for proximal tubular injury were significantly higher in female mice than in male ones. NaAsO2-induced histopathological alterations were consistently more evident in females than in males. Ovariectomy, but not orchiectomy significantly attenuated NaAsO2-induced renal injury. These results imply that the hypersusceptibility of female mice is attributed to estrogen signals. NaAsO2 suppressed the autophagic flux in tubular cells through the activation of ERK. Enhancements in the activation of ERK were significantly greater in females than in males, with the eventual accumulation of LC3-II and P62 in the kidneys, implying that the autophagic flux is impaired in females. The IL-6/STAT3 signaling pathway had protective roles in NaAsO2-induced nephrotoxicity through the suppression of ERK activation. Despite the absence of differences in intrarenal IL-6 expression between male and female mice, STAT3 was less activated with enhanced SOCS3 expression in females than in males. An in vitro study using mProx24 cells revealed that the estrogen treatment induced SOCS3 expression, and eventually suppressed the autophagic flux, as evidenced by greater increases in the accumulation of LC3-II and p62 with ERK activation, which was canceled by the knockdown of Socs3. Collectively, these results indicate that estrogen has a negative impact on the development of NaAsO2 nephrotoxicity through its suppression of the autophagic flux.

Role of endothelin receptor antagonist; bosentan in cisplatin-induced nephrotoxicity in ovariectomized estradiol treated rats

Background: Endothelin-1 (ET-1) is a vasoconstrictor peptide that mediates cell proliferation, fibrosis, and inflammation. ET-1 has 2 receptors A and B.

Objectives: The present study investigated whether administration of ET-1 receptor type A antagonist leads to protect cisplatin (CP) induced nephrotoxicity in ovariectomized-estradiol (Es) treated rats.

Materials and Methods: Thirty-six ovariectomized Wistar rats were divided into 6 groups. Group 1 received CP (2.5 mg/kg/day) for one week. Groups 2 and 3 received 2 different doses of Es (0.25 and 0.5 mg/kg/week) for 3 weeks, but CP was started in the third week. Group 4 was treated as group 1, but bosentan (BOS, 30 mg/kg/day) was also added. Groups 5 and 6 treated similar to groups 2 and 3 but CP and BOS were added in the third week. At the end of the experiment, blood samples were obtained, and the animals were sacrificed for histopathological investigation of kidney tissue.

Results: The serum levels of creatinine (Cr) and blood urea nitrogen (BUN) increased by CP; however, BOS significantly elevated the BUN and Cr levels that were increased by CP administration (P < 0.05). Co-treatment of Es, BOS, and CP decreased the serum levels of BUN, Cr, and malondialdehyde (MDA) when compared with the group treated with BOS plus CP (P < 0.05). Such finding was obtained for kidney tissue damage score (KTDS). As expected, Es significantly increased uterus weight (P < 0.05). The groups were not significantly different in terms of serum and kidney nitrite, kidney weight (KW), and bodyweight

Conclusions: According to our findings, BOS could not protect renal functions against CP-induced nephrotoxicity. In contrast, Es alone or accompanied with BOS could protect the kidney against CP-induced nephrotoxicity via reduction of BUN, Cr, and KTDS.

The effect of an specific inducible NO synthase inhibitor, S-methylisothiourea hemisulfate on cisplatin-induced nephrotoxicity; gender-related differences

Backgrounds:

It has been previously demonstrated that the increase of nitric oxide (NO) level may promote cisplatin (CP)-induced nephrotoxicity. The aim of this study was to investigate the role of inducible NO synthase (iNOS) inhibitor to prevent CP-induced nephrotoxicity.

Materials and Methods:

Four groups of male and four groups of female rats were treated daily with vehicle, S-methylisothiourea hemisulfate (SMT) as a selective iNOS inhibitor (5 mg/kg/twice a day), CP (2.5 mg/kg/day), and CP + SMT for 6 days. Then, all animals were sacrificed and the serum levels of creatinine (Cr), blood urea nitrogen (BUN), nitrite, and malondialdehyde (MDA) were measured. The kidney was removed immediately for histopathological study.

Results:

Our results showed that inhibition of iNOS by SMT could make different response in male and female animals. SMT therapy in male animals decreased serum BUN, Cr, nitrite, and MDA levels; and it also protected kidney against CP-induced nephrotoxicity.

Conclusion:

It is concluded that decrease in NO production by SMT has a beneficial effect on reducing CP-induced nephrotoxicity in male. However, such beneficial effect was not observed in female animals.

Nonpreventive Role of Aerobic Exercise Against Cisplatin-induced Nephrotoxicity in Female Rats

Background:

Cisplatin (CP) is a chemotherapy drug and nephrotoxicity is a major concern for CP therapy. CP-induced nephrotoxicity is gender-dependent, and the effect of aerobic exercise in females has not been reported yet while it has a beneficial effect in males. Hence, this study was designed to determine the protective role of aerobic exercise against CP-induced nephrotoxicity in female rats.

Methods:

Twenty-eight adult female rats were divided into four groups. Groups I and II had aerobic exercise on a treadmill for 8 weeks. Then, the exercise protocol was continued for another week in group I and stopped in group II. All animals in these groups received CP (2.5 mg/kg/day; i.p.) for 1-week. Groups III and IV were treated with CP and vehicle, respectively, without exercise. Finally, the animals were sacrificed for biochemical measurements and tissue histopathology investigations.

Results:

CP alone without exercise increased serum levels of blood urea nitrogen (BUN) and creatinine (Cr), kidney weight, and kidney tissue damage score (KTDS); while exercise could not attenuate these parameters in female rats. Exercise in females increased the serum levels of BUN and Cr and KTDS and weight loss (P < 0.05). Kidney nitrite levels reduce significantly in group I in compared to positive and negative control groups. Exercise also did not have beneficial effects on malondialdehyde levels in plasma and kidney.

Conclusions:

Aerobic exercise cannot reduce CP-induced nephrotoxicity in female rats. Increasing the damage in female rats may be related to female sex hormone estrogen or gender differences in renal hemodynamic and renin-angiotensin system activity in the presence of exercise. In general, it is recommended that the females under CP chemotherapy avoid exercising during treatment.

Role of endothelin-1 antagonist; bosentan, against cisplatin-induced nephrotoxicity in male and female rats

BACKGROUND

Cisplatin (CP) is a chemotherapy drug, with the major side effect of nephrotoxicity. The level of endothelin-1 (ET-1) increases during nephrotoxicity, which is accompanied with vasoconstrictive properties. Bosentan (BOS) is a nonselective ET-1 receptor antagonist, having vasodilatory and anti-hypertension effects. The purpose of this study was to investigate the renoprotective effect of BOS against CP-induced nephrotoxicity in male and female rats.

MATERIALS AND METHODS

Male and female rats were divided into six groups; groups 1-3 and 4-6 were male and female rats, respectively. Animals in groups 1 and 4 were considered as negative control and groups 2 and 5 considered as positive control groups received BOS (30 mg/kg/day) alone and CP (2.5 mg/kg/day) alone, respectively, for 1-week. The animals in groups 3 and 6 were treated with both CP and BOS. Finally, serum parameters were measured, and the kidney tissue was subjected to staining to evaluate tissue damage.

RESULTS

The serum levels of blood urea nitrogen and creatinine, kidney tissue damage score and kidney weight elevated, and body weight significantly decreased in both CP alone and in CP plus BOS-treated groups when compared with the control groups (P < 0.05), while BOS did not ameliorate these parameters neither in males nor in females. No significant differences were observed in serum levels of nitrite and malondialdehyde between the groups, but kidney tissue level of nitrite decreased significantly in CP alone and CP plus BOS-treated groups (P < 0.05).

CONCLUSION

Renoprotective effect of BOS, as ET-1 blocker, was not observed against CP-induced nephrotoxicity neither in male nor in female rats. This is while BOS promoted the severity of injuries in females.

Preventive role of estradiol on kidney injury induced by renal ischemia-reperfusion in male and female rats

Background:

Renal ischemia-reperfusion (RIR) is the main cause of renal failure. The incidence of RIR injury seems to be gender-related due to female sex hormone; estrogen. This study was designed to investigate the protective role of estrogen against RIR injury in male and ovariectomized female rats.

Methods:

Thirty-nine Wistar rats were used in this study as male and ovariectomized female rats in the sham-operated, RIR, and estradiol-treated plus RIR groups. The RIR was induced by clamping the renal vessels for 45 min and then 24 h of reperfusion. All animals finally were sacrificed for the measurements.

Results:

The serum levels of creatinine and blood urea nitrogen and kidney tissue damage score significantly increased in both male and female RIR rats (P < 0.05). Estradiol however significantly attenuated theses parameters (P < 0.05) toward normal levels in female (P < 0.05), but not in male rats. Kidney weight increased in both genders and estradiol intensified it in the male rats (P < 0.05). Uterus weight was increased by estradiol in female rats (P < 0.05) and testis weight did not alter in male rats.

Conclusions:

Estradiol demonstrated a protective role against RIR injury in female rats; however, estradiol as an antioxidant could not protect the male kidney from RIR injury.

Pomegranate Flower Extract does not Prevent Cisplatin-Induced Nephrotoxicity in Female Rats

BACKGROUND

Nephrotoxicity is the major side-effect of cisplatin (CDDP), and it is reported to be gender-related. We evaluated the effects of pomegranate flower extract (PFE) as an antioxidant on CDDP-induced nephrotoxicity in female rats.

METHODS

Twenty-three adult female rats in four groups treated as following. Groups 1 and 2 received PFE at doses of 25 and 50 (mg/kg/day), respectively, for 9 days, and from day 3 on, they also received cisplatin (CDDP) (2.5 mg/kg) daily. Group 3 was treated as group 1 expects saline instead of PFE, and group 4 received PFE (25 mg/kg/day) alone.

RESULTS

Cisplatin alone increased the serum levels of blood urea nitrogen, creatinine, and nitrite; and kidney tissue damage score and kidney weight. However, PFE not only did not ameliorate the induced nephrotoxicity, but also aggravated renal tissue damage.

CONCLUSIONS

Pomegranate extract as an antioxidant did not ameliorate CDDP-induced nephrotoxicity in female rats.

Effect of testosterone on Cisplatin-induced nephrotoxicity in surgically castrated rats

BACKGROUND

Cisplatin (CP) is an important antitumor drug with serious side effects such as nephrotoxicity. Estrogens can affect CP-induced nephrotoxicity; however, the role of testosterone (TS), the main male sex hormone, is not clear.

OBJECTIVES

This study aimed to investigate the effect of TS on CP-induced nephrotoxicity in castrated male rats.

MATERIALS AND METHODS

A total of 54 male Wistar rats were castrated and allocated into eight groups. Groups 1 through 3 respectively received 10, 50, and 100 mg/kg/wk of TS and group 4 received sesame oil for four weeks; then all four groups received 2.5 mg/kg/d CP for one week. Groups 5 through 8 received the same treatment regimen as groups 1 through 4 during first four weeks but instead of CP, they received saline for one week. Then the animals were sacrificed for biochemical and histopathologic studies.

RESULTS

CP increased the serum levels of blood urea nitrogen (BUN), creatinine (Cr), and malondialdehyde (SMDA) as well as kidney weight (KW), bodyweight (BW) loss, and kidney tissue damage score (KTDS). It significantly decreased the serum and kidney levels of nitrite and serum level of TS in comparison with the control group (P < 0.05). However, coadministration of CP and low dose of TS significantly decreased the serum levels of BUN as well as Cr and KTDS (P < 0.05). Administration of high-dose TS alone increased the SMDA level, KTDS, and KW while decreased the BW significantly (P < 0.05).

CONCLUSIONS

It seems that testosterone in low dose, i.e. physiologic dose, protects kidneys against CP-induced nephrotoxicity; however, special care is needed in CP therapy of patients with high levels of TS.

Effects of Fennel Essential Oil on Cisplatin-induced Nephrotoxicity in Ovariectomized Rats

Background:

Cisplatin (cis-diamminedichloroplatinum II (CDDP)) is an effective drug in cancer therapy to treat solid tumors. However, the drug is accompanied by nephrotoxicity. Previous reports indicated that estrogen has no protective role against CDDP-induced nephrotoxicity, but the role of phytoestrogen as an estrogenic agent in plants is not determined yet. The major composition of fennel essential oil (FEO) is trans-anethole that has estrogenic activity; so, we used FEO as a phytoestrogen source against CDDP-induced nephrotoxicity.

Materials and Methods:

Fifty-four ovariectomized Wistar rats were divided into seven groups. Groups 1-3 received different doses of FEO (250, 500, and 1000 mg/kg/day, respectively) for 10 days. Group 4 received saline for 10 days plus single dose of CDDP (7 mg/kg, intraperitoneally (ip)) at day 3. Groups 5-7 received FEO similar to groups 1-3, respectively; plus a single dose of CDDP (7 mg/kg, ip) on day 3. On day 10, the animals were sacrificed for histopathological studies.

Results:

The serum levels of blood urea nitrogen (BUN) and creatinine (Cr), kidney tissue damage score (KTDS), and kidney weight (KW) and body weight changes in CDDP-treated groups increased significantly (P < 0.05). FEO did not reduce the levels of BUN and Cr, KTDS, and KW and body weight changes. Also, the serum and tissue levels of nitrite were not altered significantly by FEO.

Conclusion:

FEO, as a source of phytoestrogen, did not induce kidney damage. In addition, FEO similar to estrogen was not a nephroprotectant agent against CDDP-induced nephrotoxicity.