Valsartan as a prophylactic treatment against breast cancer development and niche activation: What molecular sequels follow chronic AT-1R blockade?

AIMS: Transactivation of insulin-growth-factor-receptor (IGF-1R) by angiotensin-II-type-1-receptor (AT-1R) was only demonstrated in vascular-smooth-muscle cells and has never been tested in breast-cancer (BC). This investigation addressed the impact of chronic AT-1R blockade by valsartan (Val) on possible concurrent AT-1R/IGF-1R signaling inhibition, regressing BC-tumor-microenvironment (TME) cellular components activation, and hindering BC development. MAIN METHODS: The effect of different Val doses (10, 20, 40 & 80 mg/kg/day for 490 days) was tested on dimethylbenz(a)anthracene (DMBA)-induced progesterone-promoted-BC in rats. The influence on intratumoral/circulating angiotensin-II (ANG-II) levels and AT-1R/Mas-R immunofluorescent-expression were assessed. The potential AT-1R/IGF-1R crosstalk within TME-BC-stem-cells (BCSCs) and cancer-associated-fibroblasts (CAFs) was evaluated by fluorescently marking these cells and locating the immunofluorescently-stained AT-1R/IGF-1R in them using confocal-laser-microscopy and further quantified by flow cytometry. In addition, the molecular alterations following blocking AT-1R were inspected including determining Src; crucial for IGF-1R transactivation by AT-1R, Notch-1; IGF-IR transcriptional-regulator, and PI3K/Akt &IL-6/STAT expression. Further, the suppression of CSCs' capabilities to maintain pluripotency, stemness features, epithelial-to-mesenchymal-transition (EMT), and angiogenesis was evaluated by assessing NANOG gene, aldehyde-dehydrogenase (ALDH), N-cadherin and vascular-endothelial-growth-factor (VEGF), respectively. Furthermore, the proliferative marker; Ki-67, was detected by immunostaining, and tumors were histologically graded using Elston-Ellis-modified-Scarff-Bloom-Richardson method. KEY FINDINGS: Prophylactic Val significantly reduced tumor size, prolonged latency, reduced tumor histopathologic grade, decreased circulating/intratumoral-ANG-II levels, increased Mas-R, and decreased AT1R expression. AT-1R/IGF-1R were co-expressed with a high correlation coefficient on CAFs/BCSCs. Moreover, Val significantly attenuated IGF-1R transactivation and transcriptional regulation via Src and Notch-1 genes' downregulation and reduced Src/IGF-IR-associated PI3K/Akt and IL-6/STAT3 signaling. Further, Val significantly decreased intratumoral NANOG, ALDH, N-cadherin, VEGF, and Ki-67 levels. SIGNIFICANCE: Chronic Val administration carries a potential for repurposing as adjuvant or conjunct therapy for patients at high risk for BC.

Unveiling the therapeutic prospects of EGFR inhibition in rotenone-mediated parkinsonism in rats: Modulation of dopamine D3 receptor.

Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra. The dopamine D3 receptor (D3R) plays a significant role in the pathogenesis and treatment of PD. Activation of receptor tyrosine kinases (RTKs) inhibits signaling mediated by G protein-coupled receptor (GPCR). Epidermal growth factor receptors (EGFRs) and dopamine D3 receptors in the brain are directly associated with PD, both in terms of its development and potential treatment. Therefore, we investigated the impact of modulating the EGFR, a member of the RTKs family, and the dopamine D3R, a member of the GPCR family. In the present study, 100 mg/kg of lapatinib (LAP) was administered to rotenone-intoxicated rats for three weeks. Our findings indicate that LAP effectively alleviated motor impairment, improved histopathological abnormalities, and restored dopaminergic neurons in the substantia nigra. This restoration was achieved through the upregulation of dopamine D3R and increase of tyrosine hydroxylase (TH) expression, as well as boosting dopamine levels. Furthermore, LAP inhibited the activity of p-EGFR, GRK2, and SCR. Additionally, LAP exhibited antioxidant properties by inhibiting the 4-hydroxynonenal (4-HNE) and PLCγ/PKCßII pathway, while enhancing the antioxidant defense mechanism by increasing GSH-GPX4 pathway. The current study offers insights into the potential repositioning of LAP as a disease-modifying drug for PD. This could be achieved by modulating the dopaminergic system and curbing oxidative stress.

Exploring Parkinson-associated kinases for CRISPR/Cas9-based gene editing: beyond alpha-synuclein.

Parkinson's disease (PD) is a debilitating neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substania nigra (SN) and is associated with progressive motor impairment. PD is classified into familial and sporadic forms. The first genetic association studies in PD reported the involvement of Synuclein alpha (SNCA) mutations in the pathobiology of familial PD. Subsequent studies suggested mutations in PTEN-induced putative kinase 1 (PINK1), PARKIN, leucine repeat kinase-2 (LRRK2), and DJ-1 causing familial PD. In addition, kinase dysregulation has been embroiled in the pathogenesis of PD. The genome-editing mechanism CRISPR (clustered regularly interspaced short palindromic repeats) has recently influenced industry and scientific discoveries and is expected to expedite neurodegenerative disease research. This review will discuss the structure, function, and history of the CRISPR/Cas9 genome editing system. Moreover, it summarizes genes-encoding kinases involved in PD pathogenesis and targeted by CRISPR/Cas9 technology, including LRRK2, PINK1, Protein kinase C-delta (PKC-γ), and adenosine monophosphate-activated protein kinase (AMPK). We provide an overview of novel kinases to be targeted by the CRISPR/Cas9 system such as G-protein coupled receptor kinases (GRKs), cyclin-G-associated kinases (GAKs), cyclin-dependent kinase 5 (CDK5), Ataxia telangiectasia mutated (ATM), c-ABL, and rearranged during transfection (RET) receptors. Additionally, we will explain the off-target effects of CRISPR/Cas9 system and how to address them. Also, we will shed light on the associated challenges and future directions that are enabling the efficient use of CRISPR/Cas9 technology in kinases research in PD. In conclusion, gene editing, in addition to gene therapy, might be a possible promising strategy for PD therapy.

Pazopanib ameliorates rotenone-induced Parkinsonism in rats by suppressing multiple regulated cell death mechanisms.

Parkinson's disease (PD) is characterized by motor impairments and progressive dopaminergic neuronal death in the substantia nigra (SN). Recently, the involvement of other regulated cell death (RCD) machineries has been highlighted in PD. Necroptosis is controlled by p-RIPK1, p-RIPK3, and p-MLKL and negatively regulated by caspase-8. Ferroptosis is characterized by iron overload and accumulation of reactive oxygen species. Interestingly, the molecular chaperone complex HSP90/CDC37 has been reported to directly regulate necroptosis, ferroptosis, and some PD-associated proteins. We investigated the potential anti-necroptotic and anti-ferroptotic effects of the anti-cancer drug pazopanib, uncovering the HSP90/CDC37 complex as a master RCD modulator in rotenone-induced Parkinsonism in rats. Oral administration of 15 mg/kg pazopanib to rotenone-intoxicated rats for three weeks improved motor deficits, debilitated histopathological changes, and increased striatal dopaminergic levels. Pazopanib suppressed LRRK2 and c-Abl. Pazopanib displayed an anti-necroptotic effect through inhibition of the p-RIPK1/p-RIPK3/p-MLKL pathway and activation of caspase-8. Moreover, pazopanib inhibited the ferroptotic p-VEGFR2-PKCßII-PLC-γ-ACSL-4 pathway, iron, 4-HNE, and PTGS2 while increasing GPX-4 and GSH levels. Taken together, the current research sheds light on the repositioning of pazopanib targeting HSP90/CDC37 and its multiple RCD mechanisms, which would offer a new perspective for therapeutic strategies in PD.

Lapatinib ditosylate rescues motor deficits in rotenone-intoxicated rats: Potential repurposing of anti-cancer drug as a disease-modifying agent in Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor deficits induced by dopaminergic neuronal death in the substantia nigra (SN). Finding a successful neuroprotective therapy is still challenging despite improved knowledge of the etiology of PD and a variety of medications intended to reduce symptoms. Lapatinib (LAP), an FDA-approved anti-cancer medication, has been stated to exert its effect through the modulation of oxidative stress. Furthermore, recent studies display the neuroprotective effects of LAP in epilepsy, encephalomyelitis, and Alzheimer's disease in rodent models through the modulation of oxidative stress and ferroptosis. Nevertheless, it is questionable whether LAP exerts neuroprotective effects in PD. In the current study, administration of 100 mg/kg LAP in rotenone-treated rats for 21 days ameliorates motor impairment, debilitated histopathological alterations, and revived dopaminergic neurons by increasing tyrosine hydroxylase (TH) expression in SN, along with increased dopamine level. LAP remarkably restored the antioxidant defense mechanism system, GPX4/GSH/NRF2 axis, inhibiting oxidative markers, including iron, TfR1, PTGS2, and 4-HNE, along with suppression of p-EGFR/c-SRC/PKCßII/PLC-γ/ACSL-4 pathway. Moreover, LAP modulates HSP90/CDC37 chaperone complex, regulating many key pathological markers of PD, including LRRK2, c-ABL, and α-syn. It is concluded that LAP has neuroprotective effects in PD via modulation of many key parameters implicated in PD pathogenesis. Taken together, the current study offers insights into the potential repositioning of LAP as a disease-modifying drug in PD.

Elafibranor modulates ileal macrophage polarization to restore intestinal integrity in NASH: Potential crosstalk between ileal IL-10/STAT3 and hepatic TLR4/NF-κB axes.

Experimental and clinical evidence implicate disrupted gut barrier integrity in provoking innate immune responses, specifically macrophages, towards the progression of non-alcoholic steatohepatitis (NASH). Peroxisome proliferator-activated receptors (PPARs), a subset of the nuclear receptor superfamily, act to fine-tune several metabolic and inflammatory processes implicated in NASH. As such, the current study was carried out to decipher the potential role of dual PPAR α/δ activation using elafibranor (ELA) on ileal macrophage polarization (MP) and its likely impact on the liver in a NASH setting. To achieve this aim, an in vitro NASH model using fat-laden HepG2 cells was first used to validate the impact of ELA on hepatic fat accumulation. Afterwards, ELA was used in a combined model of dietary NASH and chronic colitis analogous to the clinical presentation of NASH parallel with intestinal barrier dysfunction. ELA mitigated fat accumulation in vitro as evidenced by Oil Red-O staining and curbed triglyceride levels. Additionally, ELA restored the expression of tight junctional proteins, claudin-1 and occludin, along with decreasing intestinal permeability and inflammation skewing ileal macrophages towards the M2 phenotype, as indicated by boosted arginase-1 (Arg1) and curtailed inducible nitric oxide synthase (iNOS) expression levels. These changes were aligned with a modulation in hepatic toll-like receptor-4 (TLR4)/nuclear factor kappa B (NF-κB) along with ileal interleukin-10 (IL-10)/signal transducer and activator of transcription-3 (STAT3) axes. Overall, the present findings suggest that the dual PPAR α/δ agonist, ELA, may drive MP in the ileum towards the M2 phenotype improving intestinal integrity towards alleviating NASH.

Enhanced antitumor activity of combined methotrexate and histone deacetylase inhibitor valproic acid on mammary cancer in vitro and in vivo.

Histone deacetylase inhibitors (HDACIs) act as antiproliferative agents by promoting differentiation and inducing apoptosis. Valproic acid (VPA) is a HDACI that shows promising chemotherapeutic effect in a number of tumor cells. The present study aimed to investigate the inhibitory effect of VPA on the viability of mammary cancer cells and its enhancing effect with methotrexate (MTX) in vitro and in vivo. Treatment with VPA or MTX alone induced concentration-dependent cytotoxic effects in two breast cancer cell lines. Valproic acid increased significantly the cytotoxicity of MTX three times against MCF7. Valproic acid addition to MTX, however, did not produce any significant changes on MTX cytotoxicity against MDA-MB231. VPA (150 and 200 mg/kg) significantly inhibited the growth of Ehrlich ascites carcinoma (EAC) and solid Ehrlich carcinoma (SEC) tumor mouse models and improved results were achieved for tumor inhibition when VPA was combined with MTX (1 and 2 mg/kg) in vivo. The antitumor activity was not associated with a significant increase in toxicity or mice mortality rate. All these findings suggest that the combination of MTX and VPA may have clinical and (or) adjuvant therapeutic application in the treatment of mammary cancer.

Repurposed anti-cancer epidermal growth factor receptor inhibitors: mechanisms of neuroprotective effects in Alzheimer's disease.

Numerous molecular mechanisms are being examined in an attempt to discover disease-modifying drugs to slow down the underlying neurodegeneration in Alzheimer's disease. Recent studies have shown the beneficial effects of epidermal growth factor receptor inhibitors on the enhancement of behavioral and pathological sequelae in Alzheimer's disease. Despite the promising effects of epidermal growth factor receptor inhibitors in Alzheimer's disease, there is no irrefutable neuroprotective evidence in well-established animal models using epidermal growth factor receptor inhibitors due to many un-explored downstream signaling pathways. This caused controversy about the potential involvement of epidermal growth factor receptor inhibitors in any prospective clinical trial. In this review, the mystery beyond the under-investigation of epidermal growth factor receptor in Alzheimer's disease will be discussed. Furthermore, their molecular mechanisms in neurodegeneration will be explained. Also, we will shed light on SARS-COVID-19 induced neurological manifestations mediated by epidermal growth factor modulation. Finally, we will discuss future perspectives and under-examined epidermal growth factor receptor downstream signaling pathways that warrant more exploration. We conclude that epidermal growth factor receptor inhibitors are novel effective therapeutic approaches that require further research in attempts to be repositioned in the delay of Alzheimer's disease progression.

Inhibition of mitochondrial pyruvate carrier 1 by lapatinib ditosylate mitigates Alzheimer's-like disease in D-galactose/ovariectomized rats.

Mitochondrial, autophagic impairment, excitotoxicity, and also neuroinflammation are implicated in Alzheimer's disease (AD) pathophysiology. We postulated that inhibiting the mitochondrial pyruvate carrier-1 (MPC-1), which inhibits the activation of the mammalian target of rapamycin (mTOR), may ameliorate the neurodegeneration of hippocampal neurons in the rat AD model. To assess this, we used lapatinib ditosylate (LAP), an anti-cancer drug that inhibits MPC-1 through suppression of estrogen-related receptor-alpha (ERR-α), in D-galactose/ovariectomized rats. AD characteristics were developed in ovariectomized (OVX) rats following an 8-week injection of D-galactose (D-gal) (150 mg/kg, i.p.). The human epidermal growth factor receptor-2 (HER-2) inhibitor, LAP (100 mg/kg, p.o.) was daily administered for 3 weeks. LAP protected against D-gal/OVX-induced changes in cortical and hippocampal neurons along with improvement in learning and memory, as affirmed using Morris water maze (MWM) and novel object recognition (NOR) tests. Furthermore, LAP suppressed the hippocampal expression of Aß1-42, p-tau, HER-2, p-mTOR, GluR-II, TNF-α, P38-MAPK, NOX-1, ERR-α, and MPC-1. Also, LAP treatment leads to activation of the pro-survival PI3K/Akt pathway. As an epilogue, targeting MPC-1 in the D-gal-induced AD in OVX rats resulted in the enhancement of autophagy, and suppression of neuroinflammation and excitotoxicity. Our work proves that alterations in metabolic signaling as a result of inhibiting MPC-1 were anti-inflammatory and neuroprotective in the AD model, revealing that HER-2, MPC-1, and ERR-α may be promising therapeutic targets for AD.

Potential Repositioning of Anti-cancer EGFR Inhibitors in Alzheimer's Disease: Current Perspectives and Challenging Prospects.

Clinical trials of new drugs for Alzheimer's disease (AD) have ended with disappointing results, with tremendous resources and time. Repositioning of existing anti-cancer epidermal growth factor receptors (EGFR) inhibitors in various preclinical AD models has gained growing attention in recent years because hyperactivation of EGFR has been implicated in many neurodegenerative disorders, including AD. Many recent studies have established that EGFR inhibition suppresses reactive astrocytes, enhances autophagy, ameliorates Aß toxicity, neuroinflammation, and regenerates axonal degradation. However, there is no incontrovertible neuroprotective proof using EGFR inhibitors due to many under-explored signaling transductions, poor blood-brain barrier (BBB) permeability of the most tested drugs, and disappointing outcomes of most clinical trials. This has caused debate about the possible involvement of EGFR inhibitors in future clinical trials. In this perspective article, we recap recent studies to merge data on the neuroprotective effects of EGFR inhibition. By consequent analysis of previous data, we notably find the under-investigated neuroprotective pathways that highlight the importance of additional research of EGFR inhibitors in attempts to be repurposed as burgeoning therapeutic strategies for AD. Finally, we will discuss future prospective challenges in the repositioning of EGFR inhibitors in AD.

L-carnitine extenuates endocrine disruption, inflammatory burst and oxidative stress in carbendazim-challenged male rats via upregulation of testicular StAR and FABP9, and downregulation of P38-MAPK pathways.

We have addressed in the current study the potential of L-carnitine (LC) to extenuate the reproductive toxic insults of carbendazim (CBZ) in male rats, and the molecular mechanisms whereby carnitine would modify the spermatogenic and steroidogenic derangements invoked by the endocrine disruptor. Herein, animals received daily doses of carbendazim (100 mg/kg) by gavage for 8 weeks. Another CBZ-challenged group was co-supplemented with LC (500 mg/kg, IP) twice weekly for 8 weeks. Sperm quantity and quality (morphology, motility and viability), serum testosterone and gonadotropins, and thyroid hormone levels were assessed. Serum tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) concentrations were determined by ELISA. Oxidant/antioxidant status in rat testis was investigated via measuring testicular contents of malondialdehyde (MDA) and reduced glutathione (GSH), as well as the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Immunohistochemical localizations of the junctional protein; occludin, and inflammatory markers; inducible nitric oxide synthase (iNOS) and nuclear factor kappa beta (NF-κB) were further analyzed. A host of transduction genes that regulate spermatogenic and steroidogenic pathways, and their encoded proteins namely, Steroidogenic Acute Regulatory Protein (StAR), Fatty acid binding protein 9 (FABP9) and P38-mitogen activated protein kinase (P38-MAPK) were assessed by real time quantitative (RT-qPCR) and Western blot. LC improved rat spermiogram, testicular histological alterations and endocrine perturbances, and modulated genes' expressions and their respective proteins. In conclusion, LC effects appear to reside for the most part on its endocrine-preserving, anti-oxidant and anti-inflammatory properties through a myriad of interlaced signal transductions that ultimately recapitulated its beneficial effects on spermatogenesis and steroidogenesis.

Lapatinib ditosylate rescues memory impairment in D-galactose/ovariectomized rats: Potential repositioning of an anti-cancer drug for the treatment of Alzheimer's disease.

Epidermal growth factor receptor (EGFR) signaling plays a substantial role in learning and memory. The upregulation of EGFR has been embroiled in the pathophysiology of Alzheimer's disease (AD). Nevertheless, most of EGFR-tyrosine kinase inhibitors (EGFR-TKIs) have been extensively studied for non-CNS diseases such as cancer and rheumatoid arthritis. TKIs targeting-based research in neurodegenerative disorders sounds to be lagging behind those of other diseases. Hence, this study aims to explore the molecular signaling pathways and the efficacy of treatment with lapatinib ditosylate (LAP), as one of EGFR-TKIs that has not yet been investigated in AD, on cognitive decline induced by ovariectomy (OVX) with chronic administration of D-galactose (D-gal) in female Wistar albino rats. OVX rats were injected with 150 mg/kg/day D-gal ip for 8 weeks to induce AD. Administration of 100 mg/kg/day LAP p.o. for 3 weeks starting after the 8th week of D-gal administration improved memory and debilitated histopathological alterations. LAP decreased the expression of GFAP, p-tau, and Aß 1-42. Besides, it reduced EGFR, HER-2, TNF-α, NOX-1, GluR-II, p38 MAPK, and p-mTOR. LAP increased nitrite, and neuronal pro-survival transduction proteins; p-PI3K, p-AKT, and p-GSK-3ß levels. Taken together, these findings suggest the role of LAP in ameliorating D-gal-induced AD in OVX rats via activating the pro-survival pathway; PI3K-Akt-GSK-3ß, while inhibiting p-mTOR, NOX-1, and p38 MAPK pathways. Moreover, this research offered a significant opportunity to advance awareness of the repositioning of TKI anti-cancer drugs for the treatment of AD.

Assessment of Pregabalin-Induced Cardiotoxicity in Rats: Mechanistic Role of Angiotensin 1-7.

Pregabalin (PRG) possesses great therapeutic benefits in the treatment of epilepsy, neuropathic pain, and fibromyalgia. However, clinical data have reported incidence or exacerbation of heart failure following PRG administration. Experimental data exploring cardiac alterations and its underlying mechanisms are quite scarce. The aim of the present work was to investigate the effect of PRG on morphometric, echocardiographic, neurohumoral, and histopathological parameters in rats. It was hypothesized that alterations in cardiac renin angiotensin system (RAS) might be involved in PRG-induced cardiotoxicity. To further emphasize the role of RAS in the mechanism of PRG-induced cardiotoxicity, the protective potential of diminazene aceturate (DIZE), an ACE2 activator, was investigated. Results showed 44% decrease in ejection fraction and sevenfold increase in plasma N-terminal pro-brain natriuretic peptide. Histopathological examination also showed prominent vacuolar changes and edema in cardiomyocytes. In addition, PRG significantly increased angiotensin II (Ang II), angiotensin converting enzyme (ACE) and angiotensin II type 1 receptor (AT1R) levels, while decreased angiotensin 1-7 (Ang 1-7), angiotensin converting enzyme 2 (ACE2), and Mas receptor (MasR) cardiac levels. DIZE co-administration showed prominent protection against PRG-induced echocardiographic, neurohumoral, and histopathological alterations in rats. In addition, downregulation of ACE/Ang II/AT1R and upregulation of ACE2/Ang 1-7/MasR axes were noted in DIZE co-treated rats. These findings showed, for the first time, the detailed cardiac deleterious effects of PRG in rats. The underlying pathophysiological mechanism is probably mediated via altered balance between the RAS axes in favor to the ACE/Ang II/AT1R pathway. Accordingly, ACE2 activators might represent promising therapeutic agents for PRG-induced cardiotoxicity.

Telmisartan and captopril ameliorate pregabalin-induced heart failure in rats.

Pregabalin (PRG) is highly effective in the treatment of epilepsy, neuropathic pain and anxiety disorders. Despite its potential benefits, PRG administration has been reported to induce or exacerbate heart failure (HF). It has been previously documented that overactivation of the renin angiotensin system (RAS) is involved in HF pathophysiological mechanism. The target of the current study was to examine the possible cardioprotective effect of telmisartan (Tel), an angiotensin II type 1 receptor (AT1R) blocker, compared with that of captopril (Cap), an angiotensin converting enzyme (ACE) inhibitor, in ameliorating PRG-induced HF in rats by assessing morphometric, echocardiographic and histopathological parameters. Furthermore, to investigate the role of RAS blockade by the two drugs in guarding against PRG-induced changes in cardiac angiotensin 1-7 (Ang 1-7) and angiotensin II (Ang II) levels, in addition to myocardial expression of ACE2, ACE, Mas receptor (MasR) and AT1R. Results showed that PRG administration induced morphometric, echocardiographic and histopathological deleterious alterations and significantly elevated cardiac Ang II, ACE and AT1R levels, while reduced Ang 1-7, ACE2 and MasR cardiac levels. Concurrent treatment with either Tel or Cap reversed PRG-induced morphometric, echocardiographic and histopathological abnormalities and revealed prominent protection against PRG-induced HF via downregulation of ACE/Ang II/AT1R and upregulation of ACE2/Ang 1-7/MasR axes. These are the first findings to demonstrate that the potential benefits of Tel and Cap are mediated by counteracting the altered balance between the RAS axes induced by PRG. Hence; Tel and Cap may attenuate PRG-induced HF partially through stimulation of ACE2/Ang 1-7/MasR pathway.

Phosphodiestrase-1 and 4 inhibitors ameliorate liver fibrosis in rats: Modulation of cAMP/CREB/TLR4 inflammatory and fibrogenic pathways.

BACKGROUND: Phosphodiestrase (PDE) enzymes are suggested to play a leading role in fibrogenesis of liver where studies showed the possible implication of PDE 1 & 4 in liver injury proposing them as possible targets for treating liver fibrosis. AIM: The present study was designed to investigate, for the first time, the possible therapeutic effects of selective inhibitors of PDE-1 (vinpocetine) and PDE-4 (roflumilast) in liver fibrosis induced by diethylnitrosamine (DEN) in rats. MAIN METHODS: Rats were given DEN (100 mg/kg, i.p.) once weekly for 6 weeks to induce liver fibrosis. Vinpocetine (10 mg/kg/day) or roflumilast (0.5 mg/kg/day) was then orally administered for 2 weeks. KEY FINDINGS: Vinpocetine significantly suppressed the contents of hydroxyproline, transforming growth factor-beta 1 (TGF-ß1), nuclear factor-kappa B (NF-κB) whereas roflumilast normalized them. Moreover, tumor necrosis factor-alpha (TNF-α) content and protein expressions of toll-like receptor 4 (TLR4) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were markedly decreased whereas cAMP response element binding (CREB) protein expression was significantly elevated by both treatments. Additionally, vinpocetine and roflumilast up-regulated the gene expression of bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) receptor where roflumilast showed better results. PDE1 and 4 activities were inhibited by vinpocetine and roflumilast, respectively. The superior results offered by roflumilast could be related to the higher cAMP level obtained relative to vinpocetine. SIGNIFICANCE: Our study manifested the up-regulation of PDE enzymes (1 & 4) in liver fibrosis and addressed the therapeutic role of vinpocetine and roflumilast as PDEIs through a cAMP-mediated TLR4 inflammatory and fibrogenic signaling pathways.

The sole and combined effect of simvastatin and platelet rich fibrin as a filling material in induced bone defect in tibia of albino rats.

Statins like simvastatin (SIM) have demonstrated to have pleiotropic actions other than their conventional use as antilipidemic drugs. Also, nowadays natural scaffolds like platelets rich fibrin (PRF) showed promising results on bone regeneration. Aim This study compare the regenerative power of SIM and PRF added locally each as a sole filling material on induced bone defect and evaluate the combined effect using PRF loaded with SIM. MATERIALS AND METHODS: A critical size bone defect was induced in 48 male albino rats of average weight 150-200 g and were divided into 4 groups according to the filling material. Control, PRF, SIM, and SIM/PRF group. Each group was subdivided according to the sacrificing period into two subgroups (one and two-months postoperatively). Tibial specimens were evaluated histologically using masson trichrome (MT) special stain to detect areas of new bone formation, immunohistochemically using anti- BMP2 and anti-VEGF, serum levels of Osteoprotegerin (OPG), RANKL, osteocalcin and alkaline phosphatase enzyme (ALP) were measured one and two months postoperatively using ELISA, Finally bone mineral density (BMD) at the bone defect area was analyzed using digital X-ray one and two-months postoperatively. RESULTS: The percentage of newly formed bone increased significantly in the three groups vs the control group with the highest significant increase (p < 0.001) in the SIM/PRF group one month postoperatively. Also, SIM/PRF group was the only group which showed significant bone maturation two-months postoperatively compared to the other groups. Immunohistochemical analysis showed significant increase in positively stained BMP-2 and VEGF expression (p < 0.001) in the three groups vs the control group with the highest significant increase (p < 0.001) in the SIM/PRF group. Serum bone anabolic markers increased significantly in the SIM and SIM/PRF groups. In contrast, RANKL serum level decreased significantly in the SIM and SIM/PRF group one month postoperatively with no significant decrease in the PRF group vs the control group. Digital X-ray results revealed the highest BMD percent change was found in the SIM/PRF group and showed complete bone healing two-months postoperatively.

Targeting central ß2 receptors ameliorates streptozotocin-induced neuroinflammation via inhibition of glycogen synthase kinase3 pathway in mice.

Alzheimer's disease (AD) is portrayed by progressive cognitive decline and pathological deposition of amyloid plaques as well as neurofibrillary tangles. Most of AD cases are sporadic, resulting from overlap of various environmental and genetic factors. Intra-cerebroventricular injection of streptozotocin (STZ) leads to insulin resistance brain state accompanied by memory decline, oxidative stress, and neuro-degeneration which mimic the pathologies associated with sporadic Alzheimer's disease (SAD). In the current study, protective effects of formoterol in STZ-induced SAD were studied. Formoterol-induced improvement in cognition was confirmed using Morris water maze and Y maze together with histopathological evidences. Moreover, prominent declines in oxidative stress, neuro-inflammation, and apoptotic parameters were recorded upon its injection in STZ-induced SAD mouse model. This was manifested by the decrement of malondialdehyde, hydrogen peroxide, interleukin-1ß, interleukin-6, tumor necrosis factor-α, and caspase-3levels contrary to reduced glutathione and interleukin-10 increments. Formoterol also reversed STZ-induced alteration in acetylcholine and glutamate levels. Furthermore, it could be concluded that formoterol was capable of combating STZ-induced neuro-inflammation and retarding the development of the main pathological hallmarks of AD through glycogen synthase kinase-3 deactivation.

Anti-apoptotic effect of 3-aminobenzamide, an inhibitor of poly (ADP-ribose) polymerase, against multiple organ damage induced by gamma irradiation in rats.

PURPOSE: This study aimed to investigate the effect of 3-aminobenzamide (3-AB) in doses of 5, 10 and 15 mg/kg on the inhibition of Poly (ADP-ribose) polymerase (PARP) when combined with ionizing radiation (IR). MATERIAL AND METHODS: Rats were treated intraperitonealy, one hour prior to irradiation at a dose level of 6 Gray (Gy) and were sacrificed 24 hours after irradiation. Control groups were run concurrently. RESULTS: IR led to an increase of thiobarbituric acid reactive substance (TBARS), nitrite as well as a decrease in total antioxidant capacity associated increase in myeloperoxidase (MPO) with the expression of cyclooxygenase-2 (COX-2). Moreover, IR caused an increase in serum lactate dehydrogenase (LDH) activity and cytosolyic Ca+2 associated with an expression of Caspase-3 as well as a decline in complex-I activity and adenosine triphosphate (ATP) level. Pretreatment with 5 and 10 mg/kg of 3AB guarded against the changes in all the measured parameters, conversely the dose of 15 mg/kg showed no effect on the damage induced by irradiation in the selected tissues. Moreover, 3AB has a dose-dependent effect on viability of Vero cells. CONCLUSION: The selected low doses of 3AB rather than the higher dose (15 mg/kg) protected against radiation-induced multiple organ damage.

Elucidation of the mechanism of atorvastatin-induced myopathy in a rat model.

Myopathy is among the well documented and the most disturbing adverse effects of statins. The underlying mechanism is still unknown. Mitochondrial dysfunction related to coenzyme Q10 decline is one of the proposed theories. The present study aimed to investigate the mechanism of atorvastatin-induced myopathy in rats. In addition, the mechanism of the coenzyme Q10 protection was investigated with special focus of mitochondrial alterations. Sprague-Dawely rats were treated orally either with atorvastatin (100mg/kg) or atorvastatin and coenzyme Q10 (100mg/kg). Myopathy was assessed by measuring serum creatine kinase (CK) and myoglobin levels together with examination of necrosis in type IIB fiber muscles. Mitochondrial dysfunction was evaluated by measuring muscle lactate/pyruvate ratio, ATP level, pAkt as well as mitochondrial ultrastructure examination. Atorvastatin treatment resulted in a rise in both CK (2X) and myoglobin (6X) level with graded degrees of muscle necrosis. Biochemical determinations showed prominent increase in lactate/pyruvate ratio and a decline in both ATP (>80%) and pAkt (>50%) levels. Ultrastructure examination showed mitochondrial swelling with disrupted organelle membrane. Co-treatment with coenzyme Q10 induced reduction in muscle necrosis as well as in CK and myoglobin levels. In addition, coenzyme Q10 improved all mitochondrial dysfunction parameters including mitochondrial swelling and disruption. These results presented a model for atorvastatin-induced myopathy in rats and proved that mitochondrial dysfunction is the main contributor in statin-myopathy pathophysiology.