5-Aminolevulinic acid protects against cisplatin-induced nephrotoxicity without compromising the anticancer efficiency of cisplatin in rats in vitro and in vivo

Degradation-controlled tissue extracellular sponge for rapid hemostasis and wound repair after kidney injury

Patients diagnosed with T1a cancer undergo partial nephrectomy to remove the tumors. In the process of removing the tumors, loss of kidney volume is inevitable, and current surgical methods focus solely on hemostasis and wound closure. Here, we developed an implantable form of decellularized extracellular matrix sponge to target both hemostasis and wound healing at the lesion site. A porous form of kidney decellularized matrix was achieved by fabricating a chemically cross-linked cryogel followed by lyophilization. The prepared kidney decellularized extracellular matrix sponge (kdES) was then characterized for features relevant to a hemostasis as well as a biocompatible and degradable biomaterial. Finally, histological evaluations were made after implantation in rat kidney incision model. Both gelatin sponge and kdES displayed excellent hemocompatibility and biocompatibility. However, after a 4-week observation period, kdES exhibited more favorable wound healing results at the lesion site. This suggests a promising potential for kdES as a supportive material in facilitating wound closure during partial nephrectomy surgery. KdES not only achieved rapid hemostasis for managing renal hemorrhage that is comparable to commercial hemostatic sponges, but also demonstrated superior wound healing outcomes.

Nrf2/HO-1 as a therapeutic target in renal fibrosis

Chronic kidney disease (CKD) is one of the most prevalent chronic diseases and affects between 10 and 14 % of the world's population. The World Health Organization estimates that by 2040, the disease will be fifth in prevalence. End-stage CKD is characterized by renal fibrosis, which can eventually lead to kidney failure and death. Renal fibrosis develops due to multiple injuries and involves oxidative stress and inflammation. In the human body, nuclear factor erythroid 2-related factor 2 (Nrf2) plays an important role in the expression of antioxidant, anti-inflammatory, and cytoprotective genes, which prevents oxidative stress and inflammation damage. Heme oxygenase (HO-1) is an inducible homolog influenced by heme products and after exposure to cellular stress inducers such as oxidants, inflammatory chemokines/cytokines, and tissue damage as an outcome or downstream of Nrf2 activation. HO-1 is known for its antioxidative properties, which play an important role in regulating oxidative stress. In renal diseases-induced tissue fibrosis and xenobiotics-induced renal fibrosis, Nrf2/HO-1 has been targeted with promising results. This review summarizes these studies and highlights the interesting bioactive compounds that may assist in attenuating renal fibrosis mediated by HO-1 activation. In conclusion, Nrf2/HO-1 signal activation could have a renoprotective effect strategy against CKD caused by oxidative stress, inflammation, and consequent renal fibrosis.

A Randomized Phase 2 Study of 5-Aminolevulinic Acid Hydrochloride and Sodium Ferrous Citrate for the Prevention of Nephrotoxicity Induced by Cisplatin-Based Chemotherapy of Lung Cancer

INTRODUCTION

Cisplatin-based chemotherapy was established in the 1980s, and it has been improved by the development of a short hydration protocol in lung cancer therapy. However, cisplatin-based chemotherapy is still associated with renal toxicity. Because 5-aminolevulinic acid (5-ALA) with sodium ferrous citrate (SFC) is known to be a mitochondrial activator and a heme oxygenase-1 (HO-1) inducer, 5-ALA with SFC is speculated to mitigate cisplatin-induced renal inflammation.

METHODS

We investigated the effects of oral administration of 5-ALA with SFC for preventing cisplatin-based nephrotoxicity in patients with lung cancer and evaluated its benefits for patients who received cisplatin-based chemotherapy. The primary endpoint was the significance of the difference between the serum creatinine (sCr) levels of the patients administered 5-ALA with SFC and those given placebo after course 1 of chemotherapy. The difference in the estimated glomerular filtration rate (eGFR) between the two groups was also evaluated as the secondary endpoint.

RESULTS

The double-blind, randomized two-arm studies were conducted at 15 medical facilities in Japan; 54 male and 20 female patients with lung cancer who received cisplatin-based chemotherapy between the ages of 42 and 75 years were included in the study. The compliance rate was greater than 94% in the primary assessment and subsequent drug administration periods. All enrolled patients completed the four cycles of cisplatin-based chemotherapy with short hydration. The average level of sCr on day 22 of course 1 was 0.707 mg/dL in the group treated with 5-ALA and SFC and 0.735 mg/dL in the placebo group, respectively, and the sCr in the test group was significantly lower than that in the placebo group (p = 0.038). In addition, the eGFR was significantly higher in the SPP-003 group than in the placebo group up to day 1 of course 3 (84.66 and 75.68 mL/min/1.73 m2, respectively, p = 0.02) and kept better even after the last administration of the study drug (82.37 and 73.49 mL/min/1.73 m2, respectively, p = 0.013).

CONCLUSIONS

The oral administration of 5-ALA with SFC is beneficial to patients undergoing cisplatin-based chemotherapy for lung cancer with short hydration.

5-Aminolevulinic acid combined with sodium ferrous citrate mitigates effects of heat stress on bovine oocyte developmental competence

High summer temperatures have deleterious effects on oocyte developmental competence. The antioxidant and autophagy-related properties of 5-aminolevulinic acid (5-ALA) gives the compound a broad range of biological activities. This study aimed to evaluate the effects of: 1) a high temperature-humidity index (THI) on the developmental competence of bovine oocytes, and 2) 5-ALA administration in combination with sodium ferrous citrate (SFC) during in vitro maturation (IVM) on bovine oocyte developmental competence evaluated at high THI. Bovine ovaries were collected from a local slaughterhouse at moderate environmental temperature (MT; THI of 56.2) and high environmental temperature (HT; THI of 76.7) periods; cumulus-oocyte complexes (COCs) were aspirated from medium-sized follicles, matured in vitro for 22 h, fertilized, and cultured for 10 days. For COCs collected during the HT period, 0 (control), 0.01, 0.1, 0.5, or 1 µM 5-ALA was added to the maturation medium in combination with SFC at a molar ratio of 1:0.125. The results showed that HT adversely affected blastocyst and hatching rates compared with MT. Adding 5-ALA/SFC (1 µM/0.125 µM) to the maturation medium of oocytes collected during the HT period improved cumulus cell expansion and blastocyst rates compared with the no-addition control. In conclusion, this study showed that high THI can disrupt bovine oocyte developmental competence. Adding 5-ALA to SFC ameliorates this negative effect of heat stress and improves subsequent embryo development.

Anti-Oxidant and Anti-Inflammatory Effects of Lipopolysaccharide from Rhodobacter sphaeroides against Ethanol-Induced Liver and Kidney Toxicity in Experimental Rats

This study aimed to investigate the protective effects of lipopolysaccharide from Rhodobacter sphaeroides (LPS-RS) against ethanol-induced hepatotoxicity and nephrotoxicity in experimental rats. The study involved an intact control group, LPS-RS group, two groups were given ethanol (3 and 5 g/kg/day) for 28 days, and two other groups (LPS-RS + 3 g/kg ethanol) and (LPS-RS + 5 g/kg ethanol) received a daily dose of LPS-RS (800 μg/kg) before ethanol. Ethanol significantly increased the expression of nuclear factor kappa B (NF-κB) and levels of malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in the liver tissue and decreased anti-oxidant enzymes. Hepcidin expression was downregulated in the liver, with increased serum levels of ferritin and iron. Prior-administration of LPS-RS alleviated the increase in oxidative stress and inflammatory markers, and preserved iron homeostasis markers. In the kidney, administration of ethanol caused significant increase in the expression of NF-κB and the levels of TNF-α and kidney injury markers; whereas LPS-RS + ethanol groups had significantly lower levels of those parameters. In conclusion; this study reports anti-oxidant, anti-inflammatory and iron homeostasis regulatory effects of the toll-like receptor 4 (TLR4) antagonist LPS-RS against ethanol induced toxicity in both the liver and the kidney of experimental rats.

Short-term supplementation of DHA-enriched phospholipids attenuates the nephrotoxicity of cisplatin without compromising its antitumor activity in mice

Cisplatin is one of the most effective chemotherapeutic agents used for the treatment of a wide variety of cancers. However, cisplatin has been associated with nephrotoxicity, which limits its application in clinical treatment. Various studies have indicated the protective effect of phospholipids against acute kidney injury. However, no study has focused on the different effects of phospholipids with different fatty acids on cisplatin-induced nephrotoxicity and on the combined effects of phospholipids and cisplatin in tumour-bearing mice. In the present study, the potential renoprotective effects of phospholipids with different fatty acids against cisplatin-induced nephrotoxicity were investigated by determining the serum biochemical index, renal histopathological changes, protein expression level and oxidative stress. The results showed that docosahexaenoic acid-enriched phospholipids (DHA-PL) and eicosapentaenoic acid-enriched phospholipids (EPA-PL) could alleviate cisplatin-induced nephrotoxicity by regulating the caspase signaling pathway, the SIRT1/PGC1α pathway, and the MAPK (mitogen-activated protein kinase) signaling pathway and by inhibiting oxidative stress. In particular, DHA-PL exhibited a better inhibitory effect on oxidative stress and apoptosis compared to EPA-PL. Furthermore, DHA-PL exhibited an additional effect with cisplatin on the survival of ascitic tumor-bearing mice. These findings suggested that DHA-PL are one kind of promising supplement for the alleviation of cisplatin-induced nephrotoxicity without compromising its antitumor activity.

Mitigation of cisplatin induced nephrotoxicity by casticin in male albino rats

Cisplatin (CP) is a commonly used, powerful antineoplastic drug, having numerous side effects. Casticin (CAS) is considered as a free radical scavenger and a potent antioxidant. The present research was planned to assess the curative potential of CAS on CP persuaded renal injury in male albino rats. Twenty four male albino rats were distributed into four equal groups. Group-1 was considered as a control group. Animals of Group-2 were injected with 5mg/kg of CP intraperitoneally. Group-3 was co-treated with CAS (50mg/kg) orally and injection of CP (5mg/kg). Group-4 was treated with CAS (50mg/kg) orally throughout the experiment. CP administration substantially reduced the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione S-transferase (GST), glutathione reductase (GSR), glutathione (GSH) content while increased thiobarbituric acid reactive substances (TBARS), and hydrogen peroxide (H2O2) levels. Urea, urinary creatinine, urobilinogen, urinary proteins, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels were substantially increased. In contrast, albumin and creatinine clearance was significantly reduced in CP treated group. The results demonstrated that CP significantly increased the inflammation indicators including nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), Interleukin-6 (IL-6) levels and cyclooxygenase-2 (COX-2) activity and histopathological damages. However, the administration of CAS displayed a palliative effect against CP-generated renal toxicity and recovered all parameters by bringing them to a normal level. These results revealed that the CAS is an effective compound having the curative potential to counter the CP-induced renal damage.

MDM2 inhibition improves cisplatin-induced renal injury in mice via inactivation of Notch/hes1 signaling pathway

OBJECTIVE

To explore the potential function of MDM2-mediated Notch/hes1 signaling pathway in cisplatin-induced renal injury.

METHODS

The acute renal injury models of mice after intraperitoneal injection of cisplatin in vivo, and the apoptotic models of human renal tubular epithelial (HK-2) cells induced by cisplatin in vitro, were conducted respectively. The renal function-related parameters were measured. The renal tissue pathological changes and apoptosis were observed by PAS staining and TUNEL staining, respectively. Cell viability and apoptosis were detected by MTT and flow cytometry. Notch/hes1 pathway-related proteins were tested by Western blotting.

RESULTS

After mice injected by cisplatin, the levels of Cr, BUN, urine cystatin C, urine NGAL and urine ACR were increased and GFR was decreased with the elevation of renal tubular injury scores, the upregulation of the expressions of MDM2, N1ICD, Hes1 and Cleaved caspase-3, as well as the enhancement of cell apoptosis accompanying decreased ratio of Bcl-2/Bax. However, these cisplatin-induced renal injuries of mice have been improved by MDM2 inhibition. Besides, the declined viability, increased cytotoxicity, and enhanced apoptosis were observed in cisplatin-induced HK-2 cells, with the activated Notch/hes1 pathway. Notably, the phenomenon was alleviated in cisplatin-induced HK-2 cells transfected with MDM2 shRNA, but was severer in those co-treated with AdMDM2. Moreover, Notch1 siRNA can reverse the injury of AdMDM2 on HK-2 cells.

CONCLUSION

Inhibiting MDM2 could reduce cell apoptosis through blocking Notch/hes1 signaling pathway, thus alleviating the acute renal injury caused by cisplatin.

Inhibitory Effect of Orally Administered 5-Aminolevulinic Acid on Prostate Carcinogenesis in the FVB-Transgenic Adenocarcinoma of a Mouse Prostate (FVB-TRAMP) Model

Background:

5-aminolevulinic acid (5-ALA) is a constituent of mitochondrial electron carriers, heme and cytochrome c, which are crucial for aerobic energy metabolism and cell apoptosis. We investigated the chemopreventive efficacy of 5-ALA against prostate cancer using the FVB-transgenic adenocarcinoma of mouse prostate (FVB-TRAMP) model.

Methods:

Samples were collected from 24 FVB-TRAMP mice at 12 and 20 weeks of age (named the first and second sets, respectively). Sixteen mice (from the first set) were randomly allocated into 3 treatment groups: 1) control (no treatment), 2) low dose of 5-ALA (30 mg/kg/day), and 3) high dose of 5-ALA (300 mg/kg/day). Similarly, 8 mice were divided into 2 treatment groups: 1) control and 2) high dose of 5-ALA (300 mg/kg/day). 5-ALA was orally administered to mice before cancer onset, from 6 weeks of age.

Results:

In the control group, prostate cancer was pathologically detected in 33 and 50 % of mice at 12 and 20 weeks, respectively, while 25% of 12-week old mice in the low-dose group were affected and none of the high-dose group mice developed prostate cancer. Immunohistochemical analysis showed higher expression of cytochrome c oxidase subunit 4 (COX4) in the prostate gland of the high-dose group compared to the control (P = 0.018). Similarly, enzyme-linked immunosorbent assay using lysed prostate tissue revealed higher amounts of cytochrome c in the prostate of the high-dose group compared to the control (P = 0.021). Furthermore, western blot analysis showed higher level of cleaved caspase-3 in mice in the high-dose group diagnosed with high-grade prostatic intraepithelial neoplasia.

Conclusion:

Our results suggest that oral 5-ALA may support the functional expression of mitochondrial cytochrome c and COX4, leading to caspase 3-dependent apoptosis in carcinogenesis in FVB-TRAMP mice. Future clinical studies are warranted to confirm the chemopreventive value of 5-ALA in prostate carcinogenesis.

A meta-analysis of preclinical studies using antioxidants for the prevention of cisplatin nephrotoxicity: implications for clinical application

Cisplatin is an effective chemotherapeutic drug whose clinical use and efficacy are limited by its nephrotoxicity, which affects mainly the renal tubules and vasculature. It accumulates in proximal and distal epithelial tubule cells and causes oxidative stress-mediated cell death and malfunction. Consequently, many antioxidants have been tested for their capacity to prevent cisplatin nephrotoxicity. In this study, we made a systematic review of the literature and meta-analyzed 152 articles, which tested the nephroprotective effect of isolated compounds or mixtures of natural origin on cisplatin nephrotoxicity in preclinical models. This meta-analysis identified the most effective candidates and examined the efficacy obtained by antioxidants administered by the oral and intraperitoneal routes. By comparing with a recent, similar meta-analysis performed on clinical studies, this article identifies a disconnection between preclinical and clinical research, and contextualizes, discusses, and integrates the existing preclinical information toward the optimized selection of candidates to be further explored (clinical level). Despite proved efficacy, this article discusses the barriers limiting the clinical development of natural mixtures, such as those in extracts from Calendula officinalis flowers and Heliotropium eichwaldii roots. On the contrary, isolated compounds are more straightforward candidates, among which arjunolic acid and quercetin stand out in this meta-analysis.

Protective effects of 5-aminolevulinic acid on heat stress in bovine mammary epithelial cells

OBJECTIVE

Cells have increased susceptibility to activation of apoptosis when suffering heat stress (HS). An effective supplementation strategy to mimic heat-induced apoptosis of bovine mammary epithelial cells (MECs) is necessary to maintain optimal milk production. This study aimed to investigate possible protective effects of the anti-apoptotic activity of 5-aminolevulinic acid (5-ALA) against HS-induced damage of bovine MECs.

METHODS

Bovine MECs were pretreated with or without 5-ALA at concentrations of 10, 100, and 500 μM for 24 h followed by HS (42.5°C for 24 h and 48 h). Cell viability was measured with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Real-time quantitative polymerase chain reaction and Western blotting were used to explore the regulation of genes associated with apoptosis, oxidative stress, and endoplasmic reticulum (ER) stress genes.

RESULTS

We found that 5-ALA induces cytoprotection via inhibition of apoptosis markers after HS-induced damage. Pretreatment of bovine MECs with 5-ALA resulted in dramatic upregulation of mRNA for nuclear factor erythroid-derived 2-like factor 2, heme oxygenase-1, and NAD(P)H quinone oxidoreductase 1, all of which are antioxidant stress genes. Moreover, 5-ALA pretreatment significantly suppressed HS-induced ER stress-associated markers, glucose-regulated protein 78, and C/EBP homologous protein expression levels.

CONCLUSION

5-ALA can ameliorate the ER stress in heat stressed bovine MEC via enhancing the expression of antioxidant gene.

Supplementary Oral Anamorelin Mitigates Anorexia and Skeletal Muscle Atrophy Induced by Gemcitabine Plus Cisplatin Systemic Chemotherapy in a Mouse Model

Chemotherapy-induced adverse effects can reduce the relative dose intensity and quality of life. In this study, we investigated the potential benefit of supplementary anamorelin and 5-aminolevulinic acid (5-ALA) as preventive interventions against a gemcitabine and cisplatin (GC) combination chemotherapy-induced adverse effects in a mouse model. Non-cancer-bearing C3H mice were randomly allocated as follows and treated for 2 weeks—(1) non-treated control, (2) oral anamorelin alone, (3) oral 5-ALA alone, (4) gemcitabine and cisplatin (GC) chemotherapy, (5) GC plus anamorelin, and (6) GC plus 5-ALA. GC chemotherapy significantly decreased body weight, food intake, skeletal muscle mass and induced severe gastric mucositis, which resulted in decreased ghrelin production and blood ghrelin level. The supplementation of oral anamorelin to GC chemotherapy successfully mitigated decrease of food intake during the treatment period and body weight loss at day 8. In addition, analysis of the resected muscles and stomach revealed that anamorelin suppressed chemotherapy-induced skeletal muscle atrophy by mediating the downregulation of forkhead box protein O-1 (FOXO1)/atrogin-1 signaling and gastric damage. Our findings suggest the preventive effect of anamorelin against GC combination chemotherapy, which was selected for patients with some types of advanced malignancies in clinical practice.

Theoretical Prediction of Dual-Potency Anti-Tumor Agents: Combination of Oxoplatin with Other FDA-Approved Oncology Drugs

Although Pt(II)-based drugs are widely used to treat cancer, very few molecules have been approved for routine use in chemotherapy due to their side-effects on healthy tissues. A new approach to reducing the toxicity of these drugs is generating a prodrug by increasing the oxidation state of the metallic center to Pt(IV), a less reactive form that is only activated once it enters a cell. We used theoretical tools to combine the parent Pt(IV) prodrug, oxoplatin, with the most recent FDA-approved anti-cancer drug set published by the National Institute of Health (NIH). The only prerequisite imposed for the latter was the presence of one carboxylic group in the structure, a chemical feature that ensures a link to the coordination sphere via a simple esterification procedure. Our calculations led to a series of bifunctional prodrugs ranked according to their relative stabilities and activation profiles. Of all the designed molecules, the combination of oxoplatin with aminolevulinic acid as the bioactive ligand emerged as the most promising strategy by which to design enhanced dual-potency oncology drugs.

A prospective study of oral 5-aminolevulinic acid to prevent adverse events in patients with localized prostate cancer undergoing low-dose-rate brachytherapy: Protocol of the AMBER study

Background

Radiotherapy is one of the most frequently selected treatment options for patients with prostate cancer. However, adverse effects related to the irradiated surrounding normal organs are significant clinical concerns. Specifically, genitourinary and gastrointestinal toxicities can lead to a dramatically reduced quality of life. The aim of this clinical trial is to determine the efficacy of oral 5-aminolevulinic acid (ALA) phosphate with sodium ferrous citrate (SFC) in patients treated with low-dose-rate brachytherapy (LDR-BT) using an iodine-125 seed source.

Methods

The AMBER study is a prospective, single-center trial in patients with localized prostate cancer undergoing LDR-BT. Patients who undergo supplementary extra-beam radiotherapy are excluded, whereas those who undergo pre-implantation short-term (4–6 months) androgen deprivation therapy to decrease the prostate volume and/or improve oncological outcomes are included. After the screening and registration, the patients will be instructed to take capsules of ALA-SFC twice a day (200 mg and 229.42 mg per day) for 6 months from the day of seed implantation (prescribed radiation dose of 160 Gy). Patient data will be collected before the implantation; during oral ALA-SFC treatment; and 1, 3, 6, 9, and 12 month(s) after seed implantation. The primary endpoint of this trial is the urinary frequency 3 months after seed implantation. At each visit, the 24-h urinary frequency, total voided volume, and mean voided volume on a frequency volume chart and other patient-reported outcomes are recorded. The data of the trial cases will be compared with those of historical controls, who are consecutive patients undergoing LDR-BT without supplementary extra-beam radiotherapy between January 2016 and January 2019. The number of subjects has been set to be 50 for trial cases and 150 for the historical control cases. Pre- and post-treatment clinicopathologic factors are compared between two groups.

Discussion

The goal of this trial is to determine the potential benefit of ALA-SFC in patients who undergo LDR-BT. To the best of our knowledge, this is the first study investigating the potential clinical benefit of oral ALA-SFC after radiotherapy. More evidence from a further randomized controlled trial is needed to change the standard of care and lead to better post-radiotherapy management.

Trial registration

This clinical trial was prospectively registered with the Japan Registry of Clinical Trials on 5 December 2019. The reference number is jRCTs051190077, nara0013 (Certified Review Board of Nara Medical University).

The Role of PGC-1α and Mitochondrial Biogenesis in Kidney Diseases

Chronic kidney disease (CKD) is one of the fastest growing causes of death worldwide, emphasizing the need to develop novel therapeutic approaches. CKD predisposes to acute kidney injury (AKI) and AKI favors CKD progression. Mitochondrial derangements are common features of both AKI and CKD and mitochondria-targeting therapies are under study as nephroprotective agents. PGC-1α is a master regulator of mitochondrial biogenesis and an attractive therapeutic target. Low PGC-1α levels and decreased transcription of its gene targets have been observed in both preclinical AKI (nephrotoxic, endotoxemia, and ischemia-reperfusion) and in experimental and human CKD, most notably diabetic nephropathy. In mice, PGC-1α deficiency was associated with subclinical CKD and predisposition to AKI while PGC-1α overexpression in tubular cells protected from AKI of diverse causes. Several therapeutic strategies may increase kidney PGC-1α activity and have been successfully tested in animal models. These include AMP-activated protein kinase (AMPK) activators, phosphodiesterase (PDE) inhibitors, and anti-TWEAK antibodies. In conclusion, low PGC-1α activity appears to be a common feature of AKI and CKD and recent characterization of nephroprotective approaches that increase PGC-1α activity may pave the way for nephroprotective strategies potentially effective in both AKI and CKD.

5-ALA/SFC Attenuated Binge Alcohol-Induced Gut Leakiness and Inflammatory Liver Disease in HIV Transgenic Rats

BACKGROUND

This study aimed to investigate the protective effect of 5-aminolevulinic acid (5-ALA) and sodium ferrous citrate (SFC) against binge alcohol-induced gut leakiness and inflammatory liver disease in HIV transgenic (TG) rats.

METHODS

TG rats were treated with 3 consecutive doses of binge ethanol (EtOH) with or without 5-ALA/SFC. Blood and liver tissue samples were collected at 6 hours following the last dose of EtOH.

RESULTS

Compared with the wild-type (WT) rats, the TG rats showed increased sensitivity to alcohol-mediated inflammation, as evidenced by the significantly elevated levels of serum endotoxin, AST, ALT, ED1, and ED2 staining in liver. In contrast, 5-ALA/SFC improved the above biochemical and histochemical profiles. 5-ALA/SFC also attenuated the up-regulated mRNA expression of leptin and CCL2. Furthermore, down-regulated intestinal ZO-1 protein expression was also inhibited by 5-ALA/SFC. Moreover, the expressions of HO-1, HO-2, Sirt1, and related signal transduction molecules in liver were increased by 5-ALA/SFC. These results demonstrated that 5-ALA/SFC treatment ameliorated binge alcohol exposure liver injury in a rat model of HIV-infected patients by reducing macrophage activation and expression of inflammatory cytokines/chemokines, and by inducing HO-1, HO-2, and Sirt1 expression.

CONCLUSIONS

Taken together, these findings suggested that treatment with 5-ALA/SFC has a potential therapeutic effect for binge alcohol exposure liver injury in HIV-infected patients.

5-Aminolevulinic acid exerts renoprotective effect via Nrf2 activation in murine rhabdomyolysis-induced acute kidney injury

AIM

Acute kidney injury (AKI) is associated with chronic kidney disease, as well as high mortality, but effective treatments for AKI are still lacking. A recent study reported the prevention of renal injury, such as ischemia-reperfusion injury, by 5-aminolevulinic acid (ALA), which induces an antioxidant effect. The current study aimed to investigate the effect of ALA in a rhabdomyolysis-induced mouse model of AKI created by intramuscular injection of 50% glycerol.

METHODS

Rhabdomyolysis-induced AKI was induced by an intramuscular injection of glycerol (5 mL/kg body weight) into mice. Administration of ALA (30 mg/kg, by gavage) was started from 48 h before or 24 h after glycerol injection. The mice were sacrificed at 72 h after glycerol injection. The roles of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), which is one of the Nrf2-related antioxidants, were further investigated through in vivo and in vitro methods.

RESULTS

5-aminolevulinic acid markedly reduced renal dysfunction and tubular damage in mice with rhabdomyolysis-induced AKI. ALA administration decreased oxidative stress, macrophage infiltration, and inflammatory cytokines and apoptosis. The expression of Nrf2 was upregulated by ALA administration. However, administration of Zinc protoporphyrin-9 (ZnPPIX) to inhibit HO-1 activity did not abolish these improvements by ALA. The expression of Nrf2-associated antioxidant factors other than HO-1 was also increased.

CONCLUSION

These findings indicate that ALA exerts its antioxidant activity via Nrf2-associated antioxidant factors to provide a renoprotective effect against rhabdomyolysis-induced AKI.

Dual benefit of supplementary oral 5-aminolevulinic acid to pelvic radiotherapy in a syngenic prostate cancer model

BACKGROUND

Normal tissue damage caused by radiotherapy remains the largest dose-limiting factor in radiotherapy for cancer. Therefore, the aim of this study was to investigate the supplementary oral 5-aminolevulinic acid (ALA) to standard radiation therapy as a novel radioprotective approach that would not compromise the antitumor effect of radiation in normal rectal and bladder mucosa in a syngenic prostate cancer (PCa) model.

METHODS

To evaluate the radiosensitizing effect of ALA in vitro, clonogenic survival assays were performed in DU145, PC3, and MyC-CaP cell lines. To evaluate the effect of ALA in vivo a single dose (25 Gy) of radiation with or without ALA was given to healthy mice. Next, a syngenic PCa model of MyC-CaP cells in FVB mice was created, and multiple doses (12 Gy total) of radiation were administered to the mouse pelvic area with or without ALA administration. Resected tumors, recta, and urinary bladders were immunostained with antibodies against Ki-67, γ-H2AX, CD204, and uroplakin-III. Total RNA levels in recta and urinary bladders were analyzed via RT2 Profiler polymerase chain reaction (PCR) arrays related to "Stress & Toxicity PathwayFinder," "Mitochondria," and "Inflammasomes."

RESULTS

The addition of in vitro single or in vivo repeated administration of exogenous ALA acted as a radiosensitizer for PCa cells. Rectal toxicity was characterized by histological changes including loss of surface epithelium, fibrosis, severe DNA damage, and the aggregation of M2 macrophages. Urinary bladder toxicity was characterized by bladder wall thickening and urothelium denuding. The higher dose (300 mg/kg/day) of ALA exerted a better radioprotective profile than the lower dose (30 mg/kg/day) in normal recta and urinary bladders. Out of the 252 genes tested, 35 (13.4%) were detected as relevant genes which may be involved in the radioprotective role of ALA administration. These included interleukin-1a (IL-1a), IL-1b, IL-12, chemokine (C-X-C motif) ligand 1 (CXCL1), CXCL3, and NLRP3.

CONCLUSIONS

Our study provides novel and comprehensive insights into the dual benefits including radiosensitizing PCa tumor tissues and radioprotection of normal pelvic organs from radiation therapy. Knowledge of the underlying mechanism will facilitate the search for optimal treatment parameters for supplemental oral ALA during radiotherapy for PCa.

5-Aminolevulinic acid with ferrous iron improves early renal damage and hepatic steatosis in high fat diet-induced obese mice

5-Aminolevulinic acid, a natural amino acid, activates mitochondrial respiration and induces heme oxygenase-1 expression. Obesity and type 2 diabetes mellitus are associated with age-related mitochondrial respiration defect, oxidative stress and inflammation. The aim of this study is to investigate the effects of 5-aminolevulinic acid with sodium ferrous citrate on early renal damage and hepatic steatosis. 7-Month-old C57BL/6 mice were fed with a standard diet or high fat diet for 9 weeks, which were orally administered 300 mg/kg 5-aminolevulinic acid combined with 47 mg/kg sodium ferrous citrate (5-aminolevulinic acid/sodium ferrous citrate) or vehicle for the last 5 weeks. We observed that 5-aminolevulinic acid/sodium ferrous citrate significantly decreased body weight, fat weight, hepatic lipid deposits and improved levels of blood glucose and oral glucose tolerance test. In addition, 5-aminolevulinic acid/sodium ferrous citrate suppressed increased glomerular tuft area in high fat diet-fed mice, which was associated with increased heme oxygenase-1 protein expression. Our findings demonstrate additional evidence that 5-aminolevulinic acid/sodium ferrous citrate could improve glucose and lipid metabolism in diabetic mice. 5-Aminolevulinic acid/sodium ferrous citrate has potential application in obesity or type 2 diabetes mellitus-associated disease such as diabetic nephropathy and nonalcoholic fatty liver disease.

Combination of 5-aminolevulinic acid and iron prevents skin fibrosis in murine sclerodermatous graft-versus-host disease

Scleroderma or systemic sclerosis (SSc) is a clinically heterogeneous rheumatological autoimmune disease affecting the skin, internal organs and blood vessels. There is at present no effective treatment for this condition. Our study investigated the effects of 5-aminolevulinic acid (5-ALA), which is a precursor of haem synthesis, on graft-vs-host disease (GvHD)-induced SSc murine model. Lymphocytes were intravenously injected from donor mice (B10.D2) into recipient BALB/c mice (recombination-activating gene 2 (Rag-2)-null mice) deficient in mature T and B cells to induce sclerodermatous GvHD (scl-GvHD). To investigate the effect of 5-ALA on scl-GvHD, combination of 5-ALA and sodium ferrous citrate (SFC) was orally administered to the recipient mice for 9 weeks. 5-ALA/SFC treatment significantly reduced progressive inflammation and fibrosis in the skin and ears. Furthermore, 5-ALA/SFC suppressed mRNA expression of transforming growth factor-β, type I collagen and inflammatory cytokines. These results indicate that the 5-ALA/SFC combination treatment has a protective effect against tissue fibrosis and inflammation in a murine scl-GvHD-induced skin and ear inflammation and fibrosis. Furthermore, the efficacy of 5-ALA/SFC suggests important implications of HO-1 protective activity in autoimmune diseases, and therefore, 5-ALA/SFC may have promising clinical applications. These findings suggested that the 5-ALA/SFC treatment may be the potential strategies for SSc.

Hypobaric hypoxia induced renal damage is mediated by altering redox pathway

Systemic hypobaric hypoxia is reported to cause renal damage; nevertheless the exact pathophysiological mechanisms are not completely understood. Therefore, the present study aims to explore renal pathophysiology by using proteomics approach under hypobaric hypoxia. Six to eight week old male Sprague Dawley rats were exposed to hypobaric hypoxia equivalent to altitude of 7628 metres (pO₂-282mmhg) at 28°C and 55% humidity in decompression chamber for different time intervals; 1, 3, and7 days. Various physiological, proteomic and bioinformatic studies were carried out to examine the effect of chronic hypobaric hypoxia on kidney. Our data demonstrated mild to moderate degenerative tubular changes, altered renal function, injury biomarkers and systolic blood pressure with increase in duration of hypobaric hypoxia exposure. Renal proteomic analysis showed 38 differential expressed spots, out of which 25 spots were down regulated and 13 were up regulated in 7 dayhypobarichypoxic exposure group of rats as compared to normoxia control. Identified proteins were involved in specific molecular changes pertinent to endogenous redox pathways, cellular integrity and energy metabolism. The study provides an empirical evidence of renal homeostasis under hypobaric hypoxia by investigating both physiological and proteomics changes. The identification of explicit key proteins provides a valuable clue about redox signalling mediated renal damage under hypobaric hypoxia.

Far infrared radiation promotes rabbit renal proximal tubule cell proliferation and functional characteristics, and protects against cisplatin-induced nephrotoxicity

Far infrared radiation, a subdivision of the electromagnetic spectrum, is beneficial for long-term tissue healing, anti-inflammatory effects, growth promotion, sleep modulation, acceleration of microcirculation, and pain relief. We investigated if far infrared radiation is beneficial for renal proximal tubule cell cultivation and renal tissue engineering. We observed the effects of far infrared radiation on renal proximal tubules cells, including its effects on cell proliferation, gene and protein expression, and viability. We also examined the protective effects of far infrared radiation against cisplatin, a nephrotoxic agent, using the human proximal tubule cell line HK-2. We found that daily exposure to far infrared radiation for 30 min significantly increased rabbit renal proximal tubule cell proliferation in vitro, as assessed by MTT assay. Far infrared radiation was not only beneficial to renal proximal tubule cell proliferation, it also increased the expression of ATPase Na+/K+ subunit alpha 1 and glucose transporter 1, as determined by western blotting. Using quantitative polymerase chain reaction, we found that far infrared radiation enhanced CDK5R1, GNAS, NPPB, and TEK expression. In the proximal tubule cell line HK-2, far infrared radiation protected against cisplatin-mediated nephrotoxicity by reducing apoptosis. Renal proximal tubule cell cultivation with far infrared radiation exposure resulted in better cell proliferation, significantly higher ATPase Na+/K+ subunit alpha 1 and glucose transporter 1 expression, and significantly enhanced expression of CDK5R1, GNAS, NPPB, and TEK. These results suggest that far infrared radiation improves cell proliferation and differentiation. In HK-2 cells, far infrared radiation mediated protective effects against cisplatin-induced nephrotoxicity by reducing apoptosis, as indicated by flow cytometry and caspase-3 assay.

Treatment of sarcopenia and glucose intolerance through mitochondrial activation by 5-aminolevulinic acid

Recently, sarcopenia has attracted attention as therapeutic target because it constitutes a risk factor for metabolic and cardiovascular diseases. We focused 5-aminolevulinic acid (ALA) which act as electron carriers in the mitochondrial electron transport system. The mice that received ALA for 8 weeks gained muscle strength and endurance, and exhibited increased muscle mass and mitochondrial amount. Administration of ALA to sarcopenia mice aged 100 weeks and chronic kidney disease (CKD) model mice also increased muscle mass and improved physical performance. Metabolome analysis revealed increased branched-chain amino acids (BCAAs) levels in the skeletal muscle of ALA-treated mice. Quantitative PCR analysis revealed decreased expression levels in branched-chain amino acid transaminases (BCATs) that degrade BCAAs and other muscle-degrading factors, and increased levels of mitochondria-activating factors. We also studied in cultured myocytes and obtained compatible results. ALA-treated mice tended to increase body weight, but reduced blood glucose level. These suggested that ALA treatment not only activated muscle mitochondria but also enhanced muscle mass through an increase in BCAAs contents, as to improve muscle strength, endurance and glucose tolerance in mice. In these ways, muscle mitochondrial activation with ALA is suggested to be useful for the treatment of sarcopenia and glucose intolerance.

The effects of 2,3-dimercapto-1-propanesulfonic acid (DMPS) and meso-2,3-dimercaptosuccinic acid (DMSA) on the nephrotoxicity in the mouse during repeated cisplatin (CDDP) treatments

Previously, we reported that specific lower dose of sodium 2,3-dimercapto-1-propanesulfonic acid (DMPS) which is an antidote to heavy metal intoxication, inversely enhanced cisplatin (CDDP)-induced antitumor activity to S-180 cell-bearing mouse. This activity was only weak with meso-2,3-dimercaptosuccinic acid (DMSA), however. This study investigated the effects of lower doses of DMPS or DMSA on the nephrotoxicity and kinetics of CDDP. Kidney and blood isolated from female mice which received CDDP with or without DMPS or DMSA once daily for 4 days were provided for measuring levels of blood urea nitrogen (BUN) and transporter proteins (OCT2: organic cation transporter; MATE1: multidrug and toxin extrusion) mRNA, and CDDP-originated platinum, and TUNEL staining of renal tubular cells. DMPS or DMSA reduced effectively CDDP-induced BUN, and caused a moderate reduction of platinum in kidney. Additionally, both dimercapto-compounds restored the CDDP-reduced mRNA levels of transporter proteins (OCT2 and MATE1), and apparently suppressed the CDDP-induced apoptosis. These results suggest that DMPS, as well as DMSA, at approximate 17-fold dose (μmol/kg) of CDDP, has an enough potential to reverse the CDDP nephrotoxicity, and concomitant use of DMPS considering both dose and timing for administration is potentially useful for preventing nephrotoxicity and enhancing antitumor activity during CDDP chemotherapy.

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.

Inhibition of PARP activation by enalapril is crucial for its renoprotective effect in cisplatin-induced nephrotoxicity in rats

Oxidative stress-induced PARP activation has been recognized to be a main factor in the pathogenesis of cisplatin-induced nephrotoxicity. Accumulating literature has revealed that ACE inhibitors may exert beneficial effect in several disease models via preventing PARP activation. Based on this hypothesis, we have evaluated the renoprotective effect of enalapril, an ACE inhibitor, and its underlying mechanism(s) in cisplatin-induced renal injury in rats. Male Albino Wistar rats were orally administered normal saline or enalapril (10, 20 and 40 mg/kg) for 10 days. Nephrotoxicity was induced by a single dose of cisplatin (8 mg/kg; i.p.) on the 7th day. The animals were thereafter sacrificed on the 11th day and both the kidneys were excised and processed for biochemical, histopathological, molecular, and immunohistochemical studies. Enalapril (40 mg/kg) significantly prevented cisplatin-induced renal dysfunction. In comparison to cisplatin-treated group, the elevation of BUN and creatinine levels was significantly less in this group. This improvement in kidney injury markers was well substantiated with reduced PARP expression along with phosphorylation of MAPKs including JNK/ERK/p38. Enalapril, in a dose-dependent fashion, attenuated cisplatin-induced oxidative stress as evidenced by augmented GSH, SOD and catalase activities, reduced TBARS and oxidative DNA damage (8-OHDG), and Nox-4 protein expression. Moreover, enalapril dose dependently inhibited cisplatin-induced inflammation (NF-κB/IKK-β/IL-6/Cox-2/TNF-α expressions), apoptosis (increased Bcl-2 and reduced p53, cytochrome c, Bax and caspase-3 expressions, and TUNEL/DAPI positivity) and preserved the structural integrity of the kidney. Thus, enalapril attenuated cisplatin-induced renal injury via inhibiting PARP activation and subsequent MAPKs/TNF-α/NF-κB mediated inflammatory and apoptotic response.

Calcium efflux from the endoplasmic reticulum regulates cisplatin-induced apoptosis in human cervical cancer HeLa cells

The function of calcium efflux from the endoplasmic reticulum (ER) in cisplatin-induced apoptosis is not fully understood in cancer cells. The present study used western blot analysis, flow cytometry, immunofluorescence and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay to investigate calcium signaling in human cervical cancer cells exposed to cisplatin. In the present study, treatment with cisplatin increased free Ca²⁺ levels in the cytoplasm and mitochondria of human cervical cancer HeLa cells, which further triggers the mitochondria-mediated and ER stress-associated apoptosis pathways. Notably, blocking calcium signaling using the calcium chelating agent bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid acetoxymethyl ester inhibited cisplatin-induced apoptosis via downregulation of the calcium-dependent proteases, the calpains, and innate apoptosis proteins, such as caspsae-3, caspase-4 and C/EBP homologous protein (CHOP). In addition, use of the inositol triphosphate receptor inhibitor, 2-aminoethyl diphenylborinate, to inhibit calcium efflux from the ER resulted in similar effects. This data indicated that calcium efflux from the ER plays a significant role in cisplatin-induced apoptosis in human cervical cancer HeLa cells, which provides further mechanistic insights into the tumor cell-killing effect of cisplatin and potential therapeutic strategies to improve cisplatin chemotherapy.

Lovastatin prevents cisplatin-induced activation of pro-apoptotic DNA damage response (DDR) of renal tubular epithelial cells

The platinating agent cisplatin (CisPt) is commonly used in the therapy of various types of solid tumors. The anticancer efficacy of CisPt largely depends on the formation of bivalent DNA intrastrand crosslinks, which stimulate mechanisms of the DNA damage response (DDR), thereby triggering checkpoint activation, gene expression and cell death. The clinically most relevant adverse effect associated with CisPt treatment is nephrotoxicity that results from damage to renal tubular epithelial cells. Here, we addressed the question whether the HMG-CoA-reductase inhibitor lovastatin affects the DDR of renal cells by employing rat renal proximal tubular epithelial (NRK-52E) cells as in vitro model. The data show that lovastatin has extensive inhibitory effects on CisPt-stimulated DDR of NRK-52E cells as reflected on the levels of phosphorylated ATM, Chk1, Chk2, p53 and Kap1. Mitigation of CisPt-induced DDR by lovastatin was independent of the formation of DNA damage as demonstrated by (i) the analysis of Pt-(GpG) intrastrand crosslink formation by Southwestern blot analyses and (ii) the generation of DNA strand breaks as analyzed on the level of nuclear γH2AX foci and employing the alkaline comet assay. Lovastatin protected NRK-52E cells from the cytotoxicity of high CisPt doses as shown by measuring cell viability, cellular impedance and flow cytometry-based analyses of cell death. Importantly, the statin also reduced the level of kidney DNA damage and apoptosis triggered by CisPt treatment of mice. The data show that the lipid-lowering drug lovastatin extensively counteracts pro-apoptotic signal mechanisms of the DDR of tubular epithelial cells following CisPt injury.

C-phycocyanin prevents cisplatin-induced mitochondrial dysfunction and oxidative stress

The potential of C-phycocyanin (C-PC) to prevent cisplatin (CP)-induced kidney mitochondrial dysfunction was determined in CD-1 male mice. The CP-induced mitochondrial dysfunction was characterized by ultrastructural abnormalities and by decrease in the following parameters in isolated kidney mitochondria: adenosine diphosphate (ADP)-induced oxygen consumption (state 3), respiratory control ratio, ADP/oxygen (ADP/O) ratio, adenosine triphosphate synthesis, membrane potential, calcium retention, glutathione (GSH) content, and activity of respiratory complex I, aconitase, catalase, and GSH peroxidase. These mitochondria also showed increase in hydrogen peroxide production, malondialdehyde, and 3-nitrotyrosine protein adducts content. The above-described changes, as well as CP-induced nephrotoxicity, were attenuated in mice pretreated with a single injection of C-PC. Our data suggest that the attenuation of mitochondrial abnormalities is involved in the protective effect of C-PC against CP-induced nephrotoxicity. This is the first demonstration that C-PC pretreatment prevents CP-induced mitochondrial dysfunction in mice.

Epidermal growth factor receptor inhibition with erlotinib partially prevents cisplatin-induced nephrotoxicity in rats

The effects of blocking the epidermal growth factor receptor (EGFR) in acute kidney injury (AKI) are controversial. Here we investigated the renoprotective effect of erlotinib, a selective tyrosine kinase inhibitor that can block EGFR activity, on cisplatin (CP)-induced AKI. Groups of animals were given either erlotinib or vehicle from one day before up to Day 3 following induction of CP-nephrotoxicity (CP-N). In addition, we analyzed the effects of erlotinib on signaling pathways involved in CP-N by using human renal proximal tubular cells (HK-2). Compared to controls, rats treated with erlotinib exhibited significant improvement of renal function and attenuation of tubulointerstitial injury, and reduced the number of apoptotic and proliferating cells. Erlotinib-treated rats had a significant reduction of renal cortical mRNA for profibrogenic genes. The Bax/Bcl-2 mRNA and protein ratios were significantly reduced by erlotinib treatment. In vitro, we observed that erlotinib significantly reduced the phosphorylation of MEK1 and Akt, processes that were induced by CP in HK-2. Taken together, these data indicate that erlotinib has renoprotective properties that are likely mediated through decreases in the apoptosis and proliferation of tubular cells, effects that reflect inhibition of downstream signaling pathways of EGFR. These results suggest that erlotinib may be useful for preventing AKI in patients receiving CP chemotherapy.

Tempol, a superoxide dismutase mimetic agent, ameliorates cisplatin-induced nephrotoxicity through alleviation of mitochondrial dysfunction in mice

Background

Mitochondrial dysfunction is a crucial mechanism by which cisplatin, a potent chemotherapeutic agent, causes nephrotoxicity where mitochondrial electron transport complexes are shifted mostly toward imbalanced reactive oxygen species versus energy production. In the present study, the protective role of tempol, a membrane-permeable superoxide dismutase mimetic agent, was evaluated on mitochondrial dysfunction and the subsequent damage induced by cisplatin nephrotoxicity in mice.

Methods and Findings

Nephrotoxicity was assessed 72 h after a single i.p. injection of cisplatin (25 mg/kg) with or without oral administration of tempol (100 mg/kg/day). Serum creatinine and urea as well as glucosuria and proteinuria were evaluated. Both kidneys were isolated for estimation of oxidative stress markers, adenosine triphosphate (ATP) content and caspase-3 activity. Moreover, mitochondrial oxidative phosphorylation capacity, complexes I–IV activities and mitochondrial nitric oxide synthase (mNOS) protein expression were measured along with histological examinations of renal tubular damage and mitochondrial ultrastructural changes. Tempol was effective against cisplatin-induced elevation of serum creatinine and urea as well as glucosuria and proteinuria. Moreover, pretreatment with tempol notably inhibited cisplatin-induced oxidative stress and disruption of mitochondrial function by restoring mitochondrial oxidative phosphorylation, complexes I and III activities, mNOS protein expression and ATP content. Tempol also provided significant protection against apoptosis, tubular damage and mitochondrial ultrastructural changes. Interestingly, tempol did not interfere with the cytotoxic effect of cisplatin against the growth of solid Ehrlich carcinoma.

Conclusion

This study highlights the potential role of tempol in inhibiting cisplatin-induced nephrotoxicity without affecting its antitumor activity via amelioration of oxidative stress and mitochondrial dysfunction.