Targeting the proinflammatory cytokines, oxidative stress, apoptosis and TGF-β1/STAT-3 signaling by irbesartan to ameliorate doxorubicin-induced hepatotoxicity

Nano-emulsion based on Santolina chamaecyparissus essential oil potentiates the cytotoxic and apoptotic effects of Doxorubicin: an in vitro study

AIM

This study was aimed at investigating the cytotoxic effect of a novel combination of doxorubicin (DOX) and nano-formulation of Santolina chamaecyparissus L. essential oil (SCEO-NANO) on hepatic (HepG2) and colon (HT29) cancer cell lines.

METHODS

A nano-emulsion was prepared by high-pressure homogenisation, then analysed by zetasizer and Fourier transform infrared spectroscopy. HepG2 and HT29 cells were used in in vitro tests for apoptosis detection.

RESULTS

Formulated droplet size increased in DOX@SCEO-NANO/DOX to 11.54 ± 0.02 with uniform distribution (PDI = 0.13 ± 0.01), when compared with SCEO-NANO (size: 8.91 ± 0.02 nm; PDI = 0.1 ± 0.02). In both cells, DOX@SCEO-NANO/DOX led to a considerable reduction in colony formation. Compared to DOX, apoprotein proteins were overexpressed in HepG2 cells, showing increases of 8.66-fold for caspase-3 and 4.24-fold for the Bax/Bcl-2 ratio. In HT29 cells, ROS-dependent necrosis and apoptosis were seen. Comparing DOX@SCEO-NANO/DOX versus DOX, greater levels of caspase-3 and the Bax/Bcl-2 ratio were observed.

CONCLUSION

The DOX@SCEO-NANO/DOX formulation showed potential for targeted eradication of colon adenocarcinoma and hepatocellular carcinoma cells.

Protective effect of irbesartan against hepatic ischemia-reperfusion injury in rats: role of ERK, STAT3, and PPAR-γ inflammatory pathways in rats

This study aimed to elucidate the possible hepatocellular protective role of irbesartan during hepatic ischemia-reperfusion injury (HIRI) and the probable underlying mechanisms. Wistar rats were allocated into four groups: sham; HIRI (control); irbesartan (50 mg/kg) + HIRI; irbesartan (100 mg/kg) + HIRI; irbesartan + GW9662 (1 mg/kg, i.p.) + HIRI. Rats pretreated orally with irbesartan or vehicle for 14 days underwent 45-min hepatic ischemia followed by 60-min reperfusion. Irbesartan preconditioning diminished alanine transaminase (ALT) and aspartate transaminase (AST) serum levels, and reduced extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription 3 (STAT3). Irbesartan decreased proapoptotic BAX (bcl-2-like protein 4), increased anti-apoptotic B-cell lymphoma 2 (BCL2) hepatic content, and thereby reduced BAX/BCL2 ratio. Moreover, irbesartan preconditioning reduced autophagy-related proteins Beclin1 and LC3 II, and elevated p62 (protein responsible for autophagosome degradation). It elevated proliferator-activated receptor γ (PPAR-γ), and reduced tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) hepatic gene expression. Also, hepatic protein expressions of nuclear factor kappa-B p65 (NF-κB p65) and caspase-3 were lessoned by irbesartan pretreatment in HIRI rats. However, GW9662 abrogated irbesartan's effect on HIRI. The protective effect of irbesartan on HIRI may be mediated by alleviation of ERK, STAT3, and PPAR-γ inflammatory pathways, exerting anti-apoptotic and anti-autophagic effects in HIRI in rats.

Antioxidant and anti-inflammatory potential of crocin on the doxorubicin mediated hepatotoxicity in Wistar rats

Doxorubicin (DXR) is widely used in cancer treatment. However, it has not yet been possible to prevent the side effects of DXR. The aim of this study was to investigate the hepatoprotective effect of crocin against DXR used in cancer treatment. For this reason; forty Wistar rats (male-250-300 g) were allocated into four groups (n = 10/group): Control, Crocin, DXR and DXR+Crocin. Control and Crocin groups were administered saline and crocin (40 mg/kg, i.p) for 15 days, respectively. DXR group, cumulative dose 12 mg/kg DXR, was administered for 12 days via 48 h intervals in six injections (2 mg/kg each, i.p). DXR+Crocin group, crocin (40 mg/kg-i.p) was administered for 15 days, and DXR was given as in the DXR group. The results revealed that serum liver markers (alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) increased significantly after DXR administration but recovered after crocin therapy. In addition, lipid peroxidation (MDA), and inflammatory cytokine (TNF-α) increased after DXR application and the antioxidative defense system (GSH, SOD, CAT) significantly decreased and re-achieved by crocin treatment. Our results conclude that crocin treatment was related to ameliorated hepatocellular architecture and reduced hepatic oxidative stress and inflammation in rats with DXR-induced hepatotoxicity.

Therapeutic implications of targeting autophagy and TGF-β crosstalk for the treatment of liver fibrosis

Liver fibrosis is characterized by the excessive deposition and accumulation of extracellular matrix components, mainly collagens, and occurs in response to a broad spectrum of triggers with different etiologies. Under stress conditions, autophagy serves as a highly conserved homeostatic system for cell survival and is importantly involved in various biological processes. Transforming growth factor-β1 (TGF-β1) has emerged as a central cytokine in hepatic stellate cell (HSC) activation and is the main mediator of liver fibrosis. A growing body of evidence from preclinical and clinical studies suggests that TGF-β1 regulates autophagy, a process that affects various essential (patho)physiological aspects related to liver fibrosis. This review comprehensively highlights recent advances in our understanding of cellular and molecular mechanisms of autophagy, its regulation by TGF-β, and the implication of autophagy in the pathogenesis of progressive liver disorders. Moreover, we evaluated crosstalk between autophagy and TGF-β1 signalling and discussed whether simultaneous inhibition of these pathways could represent a novel approach to improve the efficacy of anti-fibrotic therapy in the treatment of liver fibrosis.

Stimulation of Autophagy by Dapagliflozin Mitigates Cadmium-Induced Testicular Dysfunction in Rats: The Role of AMPK/mTOR and SIRT1/Nrf2/HO-1 Pathways

Cadmium (Cd) is a widespread environmental pollutant that triggers testicular dysfunction. Dapagliflozin is a selective sodium-glucose co-transporter-2 inhibitor with notable antioxidant and anti-apoptotic features. It has shown marked cardio-, reno-, hepato-, and neuroprotective effects. Yet, its effect on Cd-evoked testicular impairment has not been examined. Hence, the goal of the current study was to investigate the potential positive effect of dapagliflozin against Cd-induced testicular dysfunction in rats, with an emphasis on autophagy, apoptosis, and oxidative insult. Dapagliflozin (1 mg/kg/day) was given by oral gavage, and testicular dysfunction, impaired spermatogenesis, and biomolecular events were studied via immunohistochemistry, histopathology, and ELISA. The current findings demonstrated that dapagliflozin improved relative testicular weight, serum testosterone, and sperm count/motility and reduced sperm abnormalities, signifying mitigation of testicular impairment and spermatogenesis disruption. Moreover, dapagliflozin attenuated Cd-induced histological abnormalities and preserved testicular structure. The testicular function recovery was prompted by stimulating the cytoprotective SIRT1/Nrf2/HO-1 axis, lowering the testicular oxidative changes, and augmenting cellular antioxidants. As regards apoptosis, dapagliflozin counteracted the apoptotic machinery by downregulating the pro-apoptotic signals together with Bcl-2 upregulation. Meanwhile, dapagliflozin reactivated the impaired autophagy, as seen by a lowered accumulation of SQSTM-1/p62 and Beclin 1 upregulation. In the same context, the testicular AMPK/mTOR pathway was stimulated as evidenced by the increased p-AMPK (Ser487)/total AMPK ratio alongside the lowered p-mTOR (Ser2448)/total mTOR ratio. Together, the favorable mitigation of Cd-induced testicular impairment/disrupted spermatogenesis was driven by the antioxidant, anti-apoptotic, and pro-autophagic actions of dapagliflozin. Thus, it could serve as a tool for the management of Cd-evoked testicular dysfunction.

Andrographis paniculata (Burm.f.) Nees Alleviates Methotrexate-Induced Hepatotoxicity in Wistar Albino Rats

Andrographis paniculata is a herbal plant used in traditional medicinal approaches to treat various ailments and diseases. Methotrexate (MTX) is a clinically used immunosuppressant and anticancer drug. One of the increasing concerns with MTX use is liver toxicity. The aim of this study is to investigate the potential effect of aqueous leaf extract of Andrographis paniculata against methotrexate-induced hepatotoxicity. Wistar albino rats were grouped into five groups, and the drugs were administered. MTX (20 mg/kg b.w.) was intraperitoneally injected into rats on the ninth day alone. Aqueous leaf extract of Andrographis paniculata (500 mg/kg b.w./day) was orally administered for 10 days. We confirmed the beneficial effect of aqueous extracts of Andrographis paniculata on restoring the hepatic enzyme markers, lipid profile, antioxidant level, anti-inflammatory marker (IL-10), anti-apoptosis (bcl-2), significant suppression of inflammatory cytokines (TNF-α, and IL-6), apoptosis marker (caspase 3) and cellular tissue damage caused by MTX. Overall, we revealed that Andrographis paniculata reduces critical aspects of oxidative stress, inflammatory processes, and apoptosis, thus protecting against methotrexate-induced hepatotoxicity.

Fe3O4/Au/porous Au nanohybrid for efficient delivery of doxorubicin as a model drug

Fe₃O₄/Au/porous Au nanohybrids being bi-functional nanoparticles with magnetic properties and high porosity, were synthesized and used for drug delivery. To achieve this purpose, after Fe₃O₄ nanoparticles synthesis, a gold layer coats them to increase their stability. Then, to improve the loading capacity of Fe₃O₄/Au nanoparticles, a shell of porous gold was synthesized on the Fe₃O₄/Au surface by creating an Ag-Au nanohybrid layer on Fe₃O₄/Au and dissolving the metallic silver atoms in HNO₃ (0.01 M). The DLS results show that the synthesized nanohybrid has an average size of 68.0 ± 7.7 nm and a zeta potential of - 28.1 ± 0.2 mV. Finally, doxorubicin (DOX), as a pharmaceutical agent, was loaded onto the Fe₃O₄/Au/porous Au nanohybrids. The prepared nano-drug enhanced the therapeutic efficacy of DOX on MCF-7 cancer cells compared to the free DOX. These results confirmed a 1.5 times improvement in the antitumor activity of DOX-loaded Fe₃O₄/Au/porous Au nanohybrids.

New Mechanistic Insight into the Protective Effects of Ganoderma lucidum Polysaccharides Against Palmitic Acid-Induced Cell Damage in Porcine Intestinal Epithelial Cell Line IPEC-J2

Ganoderma lucidum ( G. lucidum) is one of the well-known mushrooms in China, which has G. lucidum polysaccharides (GLP) that have been widely studied for various biological activities, such as antioxidant, antitumor, antiinflammatory, antiviral, antidiabetes, and immunomodulatory activities. A signal transducer and activator of transcription (STAT) signaling pathway is related to cell proliferation and apoptosis. The relationship between STAT and intestinal protection of GLP is still unknown. We studied the inhibitors AG490 in the STAT pathway and its downstream molecules to analyze the unique effects in the protection of GLP against palmitic acid (PA)-induced porcine intestinal epithelial cells (IPEC-J2) injury. Compared to PA treatment, GLP + PA obviously decreased Ca2+ concentration, H2O2 production, NF-E2-related factor 2 (Nrf2) nuclear translocation, STAT1 and STAT2 protein levels, and increased nuclear factor kappa-B (NF-κB) nuclear translocation and p-STAT3/STAT3 ratio in IPEC-J2 cells. After inhibition of STAT3 signaling, p-STAT3/STAT3 ratio, NF-κB nuclear translocation obviously decreased and Nrf2 nuclear translocation significantly increased in the GLP + PA group. The protection of GLP on proliferation and apoptosis of PA-induced IPEC-J2 cells was suppressed by inhibiting STAT3. The STAT3 pathway regulated the enterocyte-protective effects of GLP by modulating the nuclear translocation of Nrf2 and NF-κB. We provide new insights into the mechanism of STAT signaling for the protection of GLP on PA-induced intestinal epithelial cell injury.

Irbesartan reprofiling for the amelioration of ethanol-induced gastric mucosal injury in rats: Role of inflammation, apoptosis, and autophagy

BACKGROUND

Pronounced anti-inflammatory and anti-apoptotic features have been characterized for the angiotensin receptor blocker irbesartan. Yet, its effect on ethanol-induced gastropathy has not been studied. The present work explored the potential modulation of inflammatory, apoptotic, and autophagic events by irbesartan for the attenuation of ethanol-evoked gastric mucosal injury.

METHODOLOGY

Wistar rats were divided into control, control + irbesartan, ethanol, ethanol + irbesartan, and ethanol + omeprazole groups. Macroscopic examination, histopathology, immunohistochemistry, and biochemical assays were applied to examine the gastric tissues.

KEY FINDINGS

Irbesartan administration (50 mg/kg; by gavage) in ethanol-evoked gastropathy improved the gastric pathological manifestations (area of gastric lesion and ulcer index scores), histopathological changes, and microscopic damage scores. These beneficial effects were interceded by suppression of the HMGB1-associated inflammatory events and the linked downregulation of the nuclear NF-κBp65 protein expression. In the meantime, curtailing of the NLRP3 inflammasome by irbesartan was observed with consequent decline of the pro-inflammatory cytokine IL-1β. In tandem, upregulation of the antioxidant Nrf2 and the cytoprotective PPAR-γ were seen. Together, suppression of the pro-inflammatory cues and pro-oxidant signals attenuated the pro-apoptotic events as evidenced by Bcl-2 upregulation, Bax downregulation, and caspase 3 dampened activity. Regarding gastric autophagy signals, irbesartan diminished SQSTM-1/p62 accumulation and upregulated Beclin 1. This was associated with gastric AMPK/mTOR pathway activation evidenced by increased AMPK (Ser487) phosphorylation and lowered mTOR (Ser2448) phosphorylation.

CONCLUSION

Suppression of the inflammatory and apoptotic signals and upregulation of the pro-autophagy events may advocate the promising gastroprotective actions of irbesartan against ethanol-induced gastric injury.

The therapeutic role of nutraceuticals targeting the Nrf2/HO-1 signaling pathway in liver cancer

Liver cancer (L.C.) is the most common cause of cancer death in the United States and the fifth most common globally. The overexpression of nuclear factor E2 related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) caused by oxidative stress has been associated with tumor growth, aggressiveness, treatment resistance, and poor prognosis. Nutraceuticals that inhibit Nrf2/HO-1 signaling may become the most effective strategy to treat liver cancer. Phytochemicals found in fruits and vegetables, also known as nutraceuticals, tend to emerge as chemopreventive agents, with the added benefit of low toxicity and high nutritional values. This paper reviews the present scientific knowledge of the Nrf2/HO-1 signaling as a possible target molecule for chemotherapeutic agents, its basic control mechanisms, and Nrf2/HO-1 inducers produced from natural products that might be employed as cancer chemopreventive drugs. The growing interest in the contribution of the Nrf2/ARE/HO-1 signaling in the development of liver cancer and the Use of nutraceuticals to treat liver cancer by targeting Nrf2/ARE/HO-1. PRACTICAL APPLICATIONS: An increase in Nrf2 expression indicates that Nrf2 is the most important player in liver cancer. Cancer patients are more resistant to chemotherapy because of this erroneous Nrf2 signaling. Furthermore, an increasing body of evidence indicates that activation of the Nrf2/HO-1 pathway results in the production of phase II detoxifying and antioxidant enzymes, which serve a defense purpose in cells. As a consequence, treating liver cancer. This master regulator may be a possibility. Nutraceuticals that reduce Nrf2/HO-1 signaling may be the most effective strategy for preventing liver cancer. The methods of action of numerous natural substances are examined in this article.

Irbesartan decreased mitochondrial stress related apoptosis in cisplatin induced acute kidney injury via regulating BCL-2/BAX signaling

BACKGROUND

Cisplatin (CPN) is used in the treatment of various cancers. However, the especially nephrotoxic effect is limiting its use. We aimed to evaluate the renoprotective effects of Irbesartan (IBN) on CPN-induced acute kidney injury via mitochondrial stress related apoptosis.

METHODS AND RESULTS

32 rats were divided into 4 groups as control, CPN, CPN + IBN and IBN. Water or IBN 50 mg/kg (orally) was administered for 7 days and a single dose of CPN (5 mg/kg) intraperitoneally was given CPN and CPN + IBN groups on fourth day of experiment. At the end of the experiment, serum BUN and creatinine (Cre) levels, which are the indicators of kidney function are measured. Bcl-2-associated X protein (Bax) and B-cell-lymphoma-2 (Bcl-2) mRNA levels were analyzed by using qRT-PCR from kidneys as a mitochondrial stress indicator. Also, active caspase-3(cas-3) protein and tumor necrosis factor alpha (TNF-α) expressions were examined by immunostaining of the kidney tissues. For evaluation of oxidative stress, malondialdehyde (MDA), total oxidant status (TOS) and total antioxidant status (TAS) levels of renal tissues were measured and oxidative stress index (OSI) were calculated. CPN increased serum BUN and creatinine levels. Also, MDA, TOS and OSI levels were significantly elevated and TAS levels decreased in the CPN group. Moreover, CPN elevated the levels of Bax, active cas-3 protein and TNF-α expressions and suppressed Bcl-2 levels. IBN treatment reversed all these changes.

CONCLUSIONS

IBN significantly regressed kidney damage by its anti-inflammatory and antioxidant activity via inhibiting mitochondrial stress. IBN could be used as a renoprotective agent in CPN-induced kidney injury.

Protective role of irbesartan against cyclophosphamide-induced testicular damage in rats via up-regulating PPAR-γ signaling and ameliorating NF-κB/NLRP3/IL-18 inflammatory axis

BACKGROUND

Cancer and its therapies can impact fertility in various ways, and therefore a growing number of cancer survivors face fertility as a significant concern. The cytotoxic alkylating agent cyclophosphamide (CP) is commonly used as an antineoplastic agent; unfortunately, its use is significantly associated with male infertility and damage to the reproductive system.

AIM

The present study aimed to assess the possible beneficial effects of Irbesartan (IRB) in a rat model of CP-induced testicular toxicity.

MAIN METHODS

The effects of treatment were assessed by measuring peroxisome proliferator-activated receptor gamma (PPAR-γ) expression via qRT-PCR, the immunohistochemical (IHC) assessment of apoptotic markers, NOD-like receptor protein 3 (NLRP3), and nuclear factor-κB (NF-κB), determination of the count and viability of epididymal sperm, oxidative stress markers via biochemical analysis, serum testosterone, caspase-1, and interleukin-18 (IL-18) levels via ELISA, histopathological assessment, and fibrosis by Masson's trichrome (MT) stain.

KEY FINDINGS

There was a significant increase in malondialdehyde (MDA), caspase-1, and IL-18 contents, NF-κB, NLRP3, Bcl-2-associated X protein (Bax), caspase-3, and MT staining in testicular tissue after CP administration compared to the normal control group. Whereas reduced glutathione (GSH), superoxide dismutase (SOD), PPAR-γ expression, B-cell lymphoma-2 (Bcl-2) staining, serum testosterone, and the count and viability of epididymal sperm were decreased compared to the normal control group. The IRB treatment has reversed CP-induced testicular toxicity.

SIGNIFICANCE

It is possible to conclude that IRB revealed a significant testicular protective effect against CP via antioxidant, anti-apoptotic, and anti-inflammatory effects.

Clinical efficacy of linagliptin combined with irbesartan in patients with diabetic nephropathy

Objective

To determine the clinical efficacy of linagliptin combined with irbesartan in patients with diabetic nephropathy (DN).

Methods

Seventy-two patients who were admitted to our department of endocrinology in our hospital during January 2018 and June 2019 were randomly divided into a control group (administered with irbesartan only, n=36) and a treatment group (treated with irbesartan and linagliptin, n=36). The course of treatment lasted for three months. FBG (fasting blood glucose), 2hPBG (2h postprandial blood sugar), HbA1C (hemoglobin A1c), Cys-C (cystatin C), SCr (serum creatinine), BUN (blood urea nitrogen), UACR (urine albumin-to-creatinine ratio), CRP (C-reactive protein), IL-6 (interleukin-6), and SOD (superoxide dismutase) were tested pre- and post-treatment to evaluate the clinical efficacy and adverse effects of the two treatment plans after three months of treatment.

Results

Compared with the pre-treatment levels, FBG, 2hPBG, HbA1c, Cys-C, SCr, BUN, UACR, CRP, IL-6, and SOD in both groups were significantly improved following the three-month treatment (P<0.05, respectively). Post-treatment levels of FBG, 2hPBG, HbA1c, Cys-C, SCr, BUN, UACR, CRP, and IL-6 in the treatment group were significantly lower than in the control group (P<0.05, respectively), while the treatment group exhibited a higher level of SOD compared with the control group (P<0.05). No serious adverse reaction occurred in either group (P>0.05).

Conclusion

Combined-modality treatment with linagliptin and irbesartan shows favorable clinical efficacy in treating diabetic nephropathy as it effectively protects the kidneys and improves kidney function by inhibiting inflammatory and oxidative stress responses.

Targeting Oxidative Stress, NLRP3 Inflammasome, and Autophagy by Fraxetin to Combat Doxorubicin-Induced Cardiotoxicity

Doxorubicin belongs to the class of anthracycline antibiotics that is widely used in the treatment protocols of a wide range of malignancies. The major deleterious effect of doxorubicin use is the possible occurrence of cardiotoxicity. This study aimed to delineate the possible effects of targeting oxidative stress, NLRP3 inflammasome, and autophagy by fraxetin on doxorubicin-induced cardiac dysfunction in rats. In a model of doxorubicin-induced cardiotoxicity, the effects of different doses of fraxetin were assessed by determination of biochemical, histopathological, immunohistochemical, and electron microscopic changes. Fraxetin, in a dose-dependent manner, was found to have the ability to mitigate the harmful effects of oxidative stress and inflammation on myocardial muscles with significant decrease in NLRP3 inflammasome, augmentation of autophagy, and amelioration of the apoptotic signaling pathways. In addition, fraxetin, in a dose-dependent manner, had the ability to combat the echocardiographic, histopathological, immunohistochemical, and electron microscopic changes induced by doxorubicin in cardiomyocytes. As a result, fraxetin may be put into consideration as a new adjuvant line of therapy on the way to mitigate doxorubicin-induced cardiotoxicity.

A comprehensive review on time-tested anticancer drug doxorubicin

Doxorubicin or Adriamycin, is one of the most widely used chemotherapeutic drug for treating a myriad of cancers. It induces cell death through multiple intracellular targets: reactive oxygen species generation, DNA-adduct formation, topoisomerase II inhibition, histone eviction, Ca²⁺ and iron hemostasis regulation, and ceramide overproduction. Moreover, doxorubicin-treated dying cells undergo cellular modifications that enable neighboring dendritic cell activation and enhanced presentation of tumor antigen. In addition, doxorubicin also aids in the immune-mediated clearance of tumor cells. However, the development of chemoresistance and cardiotoxicity side effect has undermined its widespread applicability. Several formulations of doxorubicin and co-treatments with inhibitors, miRNAs, natural compounds and other chemotherapeutic drugs have been essential in reducing its dosage-dependent toxicity and combating the development of resistance. Further, more advanced research into the molecular mechanism of chemoresistance development would be vital in improving the overall survivability of clinical patients and in preventing cancer relapse.

Activation of autophagy by sitagliptin attenuates cadmium-induced testicular impairment in rats: Targeting AMPK/mTOR and Nrf2/HO-1 pathways

AIMS

Cadmium (Cd) is a prevalent environmental contaminant that incurs deleterious health effects, including testicular impairment. Sitagliptin, a selective dipeptidyl peptidase-4 (DPP-4) inhibitor, has demonstrated marked cardio-, hepato-, and reno-protective actions, however, its impact on Cd-triggered testicular dysfunction has not been formerly investigated. Hence, the present study aimed to explore the probable beneficial impact of sitagliptin against Cd-evoked testicular impairment which may add to its potential clinical utility. The underlying mechanisms pertaining to the balance between testicular autophagy and apoptosis were explored, including the AMPK/mTOR and Nrf2/HO-1 pathways.

MATERIALS AND METHODS

The testicular tissues were examined using histopathology, immunohistochemistry, Western blotting, and ELISA. Sitagliptin (10 mg/kg/day, by gavage) was administered for 4 consecutive weeks.

KEY FINDINGS

Sitagliptin attenuated the testicular impairment via improvement of the relative testicular weight, sperm count/motility, sperm abnormalities, and serum testosterone. Additionally, sitagliptin counteracted Cd-induced histologic aberrations/disrupted spermatogenesis. Interestingly, sitagliptin augmented the defective autophagy as demonstrated by upregulating Beclin 1 protein expression and lowering p62 SQSTM1 protein accumulation. These effects were mediated via the activation of testicular AMPK/mTOR pathway as proven by increasing p-AMPK (Ser485, Ser491)/total AMPK and diminishing p-mTOR (Ser2448)/total mTOR protein expression. Additionally, sitagliptin suppressed the testicular apoptotic events via downregulating Bax and upregulating Bcl-2 protein expression. In tandem, sitagliptin suppressed the oxidative stress through lowering lipid peroxides and activating Nrf2/HO-1 pathway via upregulating the protein expression of Nrf2, and the downstream effectors HO-1 and GPx.

SIGNIFICANCE

Sitagliptin attenuated Cd-induced testicular injury via boosting the autophagy/apoptosis ratio through activation of AMPK/mTOR and Nrf2/HO-1 pathways.

Transferrin-Bound Doxorubicin Enhances Apoptosis and DNA Damage through the Generation of Pro-Inflammatory Responses in Human Leukemia Cells

Doxorubicin (DOX) is an effective antineoplastic drug against many solid tumors and hematological malignancies. However, the clinical use of DOX is limited, because of its unspecific mode of action. Since leukemia cells overexpress transferrin (Tf) receptors on their surface, we proposed doxorubicin–transferrin (DOX–Tf) conjugate as a new vehicle to increase drug concentration directly in cancer cells. The data obtained after experiments performed on K562 and CCRF-CEM human leukemia cell lines clearly indicate severe cytotoxic and genotoxic properties of the conjugate drug. On the other hand, normal peripheral blood mononuclear cells (PBMCs) were more resistant to DOX–Tf than to DOX. In comparison to free drug, we observed that Tf-bound DOX induced apoptosis in a TRAIL-dependent manner and caused DNA damage typical of programmed cell death. These fatal hallmarks of cell death were confirmed upon morphological observation of cells incubated with DOX or DOX–Tf. Studies of expression of TNF-α, IL-4, and IL-6 at the mRNA and protein levels revealed that the pro-inflammatory response plays an important role in the toxicity of the conjugate. Altogether, the results demonstrated here describe a mechanism of the antitumor activity of the DOX–Tf conjugate.

Low shear stress regulates vascular endothelial cell pyroptosis through miR-181b-5p/STAT-3 axis

Low shear stress and pyroptosis both play an important role in the onset and development of atherosclerosis (AS). MicroRNAs (miRNAs) are a kind of short (18-22) nucleotide sequences that can bind to the 3'-untranslated region (3'-UTR) of messenger RNA, thereby regulating programmed cell death including pyroptosis. However, the function of miRNAs in cells subjected to shear stress conditions is unknown. Therefore, we conducted the current study to demonstrate the effect of low shear stress on pyroptosis and the underlying mechanism. Human umbilical vein endothelial cells (HUVECs) stimulated by undisturbed shear stress (5 dynes/cm² ) were the experimental group while HUVECs without shear stress treatment were the control group in our experiments. We observed that shear stress can suppress mechanosensitive miR-181b-5p expression, accompanying the elevated expression of NLRP3 inflammasome-dependent pyroptosis. Introduction of miR-181b-5p could alleviate NLRP3 inflammasome-dependent pyroptosis. Luciferase assay showed specific binding of miR-181b-5p to the 3'-UTR of signal transduction and transcriptional activation factor 3 (STAT-3) gene. Inhibition of STAT-3 gene expression at the posttranscriptional level results in the alleviation of NLRP3 inflammasome-dependent pyroptosis. Besides, the silencing of STAT-3 reduced anti-miR-181b-5p-mediated HUVEC pyroptosis via regulating NLRP3 inflammasome activation. Given the role of mechanosensitive miR-181b-5p and STAT-3 in the shear stress-induced pyroptosis, regulation of their expression levels may be a promising strategy to control AS.

Iron Oxide Nanoparticles as Carriers for DOX and Magnetic Hyperthermia after Intratumoral Application into Breast Cancer in Mice: Impact and Future Perspectives

There is still a need for improving the treatment of breast cancer with doxorubicin (DOX). In this paper, we functionalized magnetic nanoparticles (MNPs) with DOX and studied the DOX-induced antitumor effects in breast cancer cells (BT474) in the presence of magnetic hyperthermia (43 °C, 1 h). We show that i) intratumoral application of DOX-functionalized MNPs (at least at a concentration of 9.6 nmol DOX/100 mm³ tumor volume) combined with magnetic hyperthermia favors tumor regression in vivo, and there is evidence for an increased effect compared to magnetic hyperthermia alone or to the intratumoral application of free DOX and ii) the presence of the pseudopeptide NucAnt (N6L) on the MNP surface might well be beneficial in its function as carrier for MNP internalization into breast cancer cells in vitro, which could further augment the possibility of the induction of intracellular heating spots and cell death in the future.

Thiamine Deficiency Modulates p38MAPK and Heme Oxygenase-1 in Mouse Brain: Association with Early Tissue and Behavioral Changes

Thiamine deficiency (TD) produces severe neurodegenerative lesions. Studies have suggested that primary neurodegenerative events are associated with both oxidative stress and inflammation. Very little is known about the downstream effects on intracellular signaling pathways involved in neuronal death. The primary aim of this work was to evaluate the modulation of p38^MAPK and the expression of heme oxygenase 1 (HO-1) in the central nervous system (CNS). Behavioral, metabolic, and morphological parameters were assessed. Mice were separated into six groups: control (Cont), TD with pyrithiamine (Ptd), TD with pyrithiamine and Trolox (Ptd + Tr), TD with pyrithiamine and dimethyl sulfoxide (Ptd + Dmso), Trolox (Tr) and DMSO (Dmso) control groups and treated for 9 days. Control groups received standard feed (AIN-93M), while TD groups received thiamine deficient feed (AIN-93DT). All the groups were subjected to behavioral tests, and CNS samples were collected for cell viability, histopathology and western blot analyses. The Ptd group showed a reduction in weight gain and feed intake, as well as a reduction in locomotor, grooming, and motor coordination activities. Also, Ptd group showed a robust increase in p38^MAPK phosphorylation and mild HO-1 expression in the cerebral cortex and thalamus. The Ptd group showed a decreased cell viability, hemorrhage, spongiosis, and astrocytic swelling in the thalamus. Groups treated with Trolox and DMSO displayed diminished p38^MAPK phosphorylation in both the structures, as well as attenuated thalamic lesions and behavioral activities. These data suggest that p38^MAPK and HO-1 are involved in the TD-induced neurodegeneration in vivo, possibly modulated by oxidative stress and neuroinflammation.

Nicorandil combats doxorubicin-induced nephrotoxicity via amendment of TLR4/P38 MAPK/NFκ-B signaling pathway

Nicorandil ameliorated doxorubicin-induced nephrotoxicity; this study aimed to show and explain the mechanism of this protection. A precise method was elucidated to study the effect of nicorandil on doxorubicin-induced nephrotoxicity in rats depending on the critical inflammation pathway TLR4/MAPK P38/NFκ-B. Adult male rats were subdivided into four groups. The 1st group was normal control, the 2nd group received nicorandil (3 mg/kg; p.o., for 4 weeks), the 3rd group received doxorubicin (2.6 mg/kg, i.p., twice per week for 4 weeks), and the fourth group was combination of doxorubicin and nicorandil for 4 weeks. Nephrotoxicity was assessed by biochemical tests through measuring Kidney function biomarkers such as [serum levels of urea, creatinine, albumin and total protein] besides renal kidney injury molecule-1 (KIM-1) and cystatin C], oxidative stress parameters such as [renal tissue malondialdehyde (MDA), reduced glutathione (GSH), SOD, catalase and nrf-2], mediators of inflammation such as [Toll like receptor 4 (TLR-4), Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), p38 MAPK, Interleukin 1 beta (IL-1 β), and Tumor necrosis factor alpha (TNF-α)] and markers of apoptosis [BAX and Bcl-2 in renal tissue]. Finally, our data were supported by histopathology examination. Nicorandil pretreatment resulted in a significant decrease in nephrotoxicity biomarkers, oxidative stress markers, inflammatory mediators and prevented apoptosis through decreasing BAX and increasing Bcl-2 in renal tissues. Nicorandil prevented all the histological alterations caused by doxorubicin. Nicorandil is a promising antidote against doxorubicin-induced nephrotoxicity by neutralizing all toxicity mechanisms caused by doxorubicin through normalizing inflammatory cascade of TLR4/MAPK P38/NFκ-B.

Pharmacokinetic interference of doxorubicin with tolbutamide due to reduced metabolic clearance with increased serum unbound fraction in rats

The study examined the effect of doxorubicin (DOX) on the hepatic expression of CYP2C and its activity for metabolizing tolbutamide (TB), a specific CYP2C substrate, in rats and whether the pharmacokinetics of tolbutamide were altered by doxorubicin exposure. The expression level of hepatic CYP2C11 was depressed 1 day after doxorubicin administration (day 1), and this effect on CYP2C11 was augmented on day 4. However, the expression level of hepatic CYP2C6 remained unchanged. The activity of tolbutamide 4-hydroxylation in hepatic microsomes was decreased with time following doxorubicin administration. Regarding the enzyme kinetic parameters for tolbutamide 4-hydroxylation on day 4, the maximum velocity (V_max ) was significantly lower in the DOX group than that in the control group, while the Michaelis constant (K_m ) was unaffected. On pharmacokinetic examination, the total clearance (CL_tot ) of tolbutamide on day 4 was increased, despite the decreased metabolic capacity. On the other hand, the serum unbound fraction (f_u ) of tolbutamide was elevated with a reduced serum albumin concentration in the DOX group. Contrary to CL_tot , CL_tot /f_u , a parameter approximated to the hepatic intrinsic clearance of unbound tolbutamide, was estimated to be significantly reduced in the DOX group. These findings indicate that the metabolic capacity of CYP2C11 in the liver is depressed time-dependently by down-regulation after doxorubicin exposure in rats, and that the decreased enzyme activity of TB 4-hydroxylation in hepatic microsomes reflects the pharmacokinetic change of unbound tolbutamide, not total tolbutamide, in serum.

MicroRNA-128-3p aggravates doxorubicin-induced liver injury by promoting oxidative stress via targeting Sirtuin-1

As one classic anticancer drug, clinical application of Doxorubicin (Dox) is limited due to its side effects. In our previous work, we have investigated the drug targets to treat Dox-induced cardiotoxicity, hepatotoxicity and nephrotoxicity. In this paper, the mechanisms and new drug-target associated with Dox-induced hepatotoxicity were explored. The results showed that Dox markedly inhibited cell viability and cellular respiration, induced cell morphologic change and increased ROS level. Moreover, Dox increased ALT and AST levels, caused pathological damage, increased MDA level and decreased SOD level in mice. Mechanism investigation showed that Dox markedly up-regulated the expression level of miR-128-3p, down-regulated Sirt1 expression level and affected the protein levels of Nrf2, Keap1, Sirt3, NQO1 and HO-1 to cause oxidative stress in liver. Furthermore, double-luciferase reporter assay, and co-transfection test showed that miR-128-3p directly targeted Sirt1. In addition, miR-128-3p mimics in AML-12 cells enhanced Dox-induced oxidative damage via inhibiting cellular respiration, increasing ROS level and mitochondrial superoxide formation. The protein levels of Sirt1, Nrf2, Sirt3, NQO1 and HO-1 in miR-128-3p mimic + Dox group were decreased compared with Dox group. Transfection of miR-128-3p inhibitor weakened Dox-induced oxidative damage via increasing cellular respiration, suppressing cellular ROS level and mitochondrial superoxide formation. The protein levels of Sirt1, Nrf2, Sirt3, NQO1 and HO-1 in miR-128-3p inhibitor + Dox group were increased compared with Dox group. In mice, Dox-induced liver damage was deteriorated by miR-128-3p agomir via increasing the levels of ALT, AST, MDA, and down-regulating the protein levels of Sirt1, Nrf2, Sirt3, NQO1 and HO-1. While, miR-128-3p antagomir alleviated liver injury via decreasing the levels of ALT, AST, MDA, and up-regulating the protein levels of Sirt1, Nrf2, Sirt3, NQO1 and HO-1. Our data showed that miRNA-128-3p aggravated Dox-induced liver injury by promoting oxidative stress via targeting Sirt1, which should be considered as one new drug target to treat Dox-induced liver injury.

Yiqi Fumai lyophilized injection attenuates doxorubicin-induced cardiotoxicity, hepatotoxicity and nephrotoxicity in rats by inhibition of oxidative stress, inflammation and apoptosis

Doxorubicin (DOX) is one of the most effective antineoplastic drugs, however, its organ toxicity inhibits the clinical utility. This study was aimed at investigating the protective effects of Yiqi Fumai lyophilized injection (YQFM) against DOX-induced tissue injury and exploring the mechanisms which mediated reactive oxygen species (ROS), inflammation and apoptosis. The experiment was as follows: rats were subjected to an intraperitoneal injection (i.p.) of YQFM (0.481 g kg-1, i.p.) for 12 days; DOX (5 mg kg-1, i.p.) was administered on the 4th, 8th and 12th days to achieve a cumulative dose of 15 mg kg-1. Pretreatment of YQFM significantly ameliorated intracellular damage and dysfunction of the heart, liver and kidneys via decreasing activities of injury indexes. The levels of lipid peroxidation and glutathione depletion were clearly reduced following YQFM pretreatment, meanwhile the activities of glutathione peroxidase, superoxide dismutase, and catalase were elevated. Additionally administering YQFM could mitigate the cardiotoxicity, hepatotoxicity and nephrotoxicity via reducing levels of inflammatory factors and decreasing apoptosis. Accordingly, this study indicated that YQFM attenuated DOX-induced toxicity by ameliorating organ function, decreasing ROS production, and preventing excessive inflammation and apoptosis.