Carvedilol, a third-generation β-blocker prevents oxidative stress-induced neuronal death and activates Nrf2/ARE pathway in HT22 cells

Mechanistic insights into carvedilol's potential protection against doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is an anthracycline chemotherapy drug widely employed in the treatment of various cancers, known for its potent antineoplastic properties but often associated with dose-dependent cardiotoxicity, limiting its clinical use. This review explores the complex molecular details that determine the heart-protective effectiveness of carvedilol in relation to cardiotoxicity caused by DOX. The harmful effects of DOX on heart cells could include oxidative stress, DNA damage, iron imbalance, disruption of autophagy, calcium imbalance, apoptosis, dysregulation of topoisomerase 2-beta, arrhythmogenicity, and inflammatory responses. This review carefully reveals how carvedilol serves as a strong protective mechanism, strategically reducing each aspect of cardiac damage caused by DOX. Carvedilol's antioxidant capabilities involve neutralizing free radicals and adjusting crucial antioxidant enzymes. It skillfully manages iron balance, controls autophagy, and restores the calcium balance essential for cellular stability. Moreover, the anti-apoptotic effects of carvedilol are outlined through the adjustment of Bcl-2 family proteins and activation of the Akt signaling pathway. The medication also controls topoisomerase 2-beta and reduces the renin-angiotensin-aldosterone system, together offering a thorough defense against cardiotoxicity induced by DOX. These findings not only provide detailed understanding into the molecular mechanisms that coordinate heart protection by carvedilol but also offer considerable potential for the creation of targeted treatment strategies intended to relieve cardiotoxicity caused by chemotherapy.

Oxidative stress in Alzheimer's disease: current knowledge of signaling pathways and therapeutics

Alzheimer's disease's pathophysiology is still a conundrum. Growing number of evidences have elucidated the involvement of oxidative stress in the pathology of AD rendering it a major target for therapeutic development. Reactive oxygen species (ROS) generated by altered mitochondrial function, dysregulated electron transport chain and other sources elevate aggregated Aβ and neurofibrillary tangles which further stimulating the production of ROS. Oxidative stress induced damage to lipids, proteins and DNA result in neuronal death which leads to AD. In addition, oxidative stress induces apoptosis that is triggered by the modulation of ERK1/2 and Nrf2 pathway followed by increased GSK-3β expression and decreased PP2A activity. Oxidative stress exaggerates disease condition by interfering with various signaling pathways like RCAN1, CREB/ERK, Nrf2, PP2A, NFκB and PI3K/Akt. Studies have reported the role of TNF-α in oxidative stress stimulation that has been regulated by drugs like etanercept increasing the level of anti-oxidants. Other drugs like pramipexole, memantine, carvedilol, and melatonin have been reported to activate CREB/RCAN1 and Nrf2 pathways. In line with this, epigallocatechin gallate and genistein also target Nrf2 and CREB pathway leading to activation of downstream pathways like ARE and Keap1 which ameliorate oxidative stress condition. Donepezil and resveratrol reduce oxidative stress and activate AMPK pathway along with PP2A activation thus promoting tau dephosphorylation and neuronal survival. This study describes in detail the role of oxidative stress in AD, major signaling pathways involving oxidative stress induced AD and drugs under development targeting these pathways which may aid in therapeutic advances for AD.

β-Adrenoceptor Blockade Moderates Neuroinflammation in Male and Female EAE Rats and Abrogates Sexual Dimorphisms in the Major Neuroinflammatory Pathways by Being More Efficient in Males

Our previous studies showed more severe experimental autoimmune encephalomyelitis (EAE) in male compared with female adult rats, and moderating effect of propranolol-induced β-adrenoceptor blockade on EAE in females, the effect associated with transcriptional stimulation of Nrf2/HO-1 axis in spinal cord microglia. This study examined putative sexual dimorphism in propranolol action on EAE severity. Propranolol treatment beginning from the onset of clinical EAE mitigated EAE severity in rats of both sexes, but to a greater extent in males exhibiting higher noradrenaline levels and myeloid cell β₂-adrenoceptor expression in spinal cord. This correlated with more prominent stimulatory effects of propranolol not only on CX3CL1/CX3CR1/Nrf2/HO-1 cascade, but also on Stat3/Socs3 signaling axis in spinal cord microglia/myeloid cells (mirrored in the decreased Stat3 and the increased Socs3 expression) from male rats compared with their female counterparts. Propranolol diminished the frequency of activated cells among microglia, increased their phagocyting/endocyting capacity, and shifted cytokine secretory profile of microglia/blood-borne myeloid cells towards an anti-inflammatory/neuroprotective phenotype. Additionally, it downregulated the expression of chemokines (CCL2, CCL19/21) driving T-cell/monocyte trafficking into spinal cord. Consequently, in propranolol-treated rats fewer activated CD4+ T cells and IL-17+ T cells, including CD4+IL17+ cells coexpressing IFN-γ/GM-CSF, were recovered from spinal cord of propranolol-treated rats compared with sex-matched saline-injected controls. All the effects of propranolol were more prominent in males. The study as a whole disclosed that sexual dimorphism in multiple molecular mechanisms implicated in EAE development may be responsible for greater severity of EAE in male rats and sexually dimorphic action of substances affecting them. Propranolol moderated EAE severity more effectively in male rats, exhibiting greater spinal cord noradrenaline (NA) levels and myeloid cell β₂-adrenoceptor (β₂-AR) expression than females. Propranolol affected CX3CR1/Nrf2/HO-1 and Stat3/Socs3 signaling axes in myeloid cells, favored their anti-inflammatory/neuroprotective phenotype and, consequently, reduced Th cell reactivation and differentiation into highly pathogenic IL-17/IFN-γ/GM-CSF-producing cells.

Adrenoceptors as potential target for add-on immunomodulatory therapy in multiple sclerosis

This review summarizes recent findings related to the role of the sympathetic nervous system (SNS) in pathogenesis of multiple sclerosis (MS) and its commonly used experimental model - experimental autoimmune encephalomyelitis (EAE). They indicate that noradrenaline, the key end-point mediator of the SNS, acting through β-adrenoceptor, has a contributory role in the early stages of MS/EAE development. This stage is characterized by the SNS hyperactivity (increased release of noradrenaline) reflecting the net effect of different factors, such as the disease-associated inflammation, stress, vitamin D hypovitaminosis, Epstein-Barr virus infection and dysbiosis. Thus, the administration of propranolol, a non-selective β-adrenoceptor blocker, readily crossing the blood-brain barrier, to experimental rats before the autoimmune challenge and in the early (preclinical/prodromal) phase of the disease mitigates EAE severity. This phenomenon has been ascribed to the alleviation of neuroinflammation (due to attenuation of primarily microglial activation/proinflammatory functions) and the diminution of the magnitude of the primary CD4+ T-cell autoimmune response (the effect associated with impaired autoantigen uptake by antigen presenting cells and their migration into draining lymph nodes). The former is partly related to breaking of the catecholamine-dependent self-amplifying microglial feed-forward loop and the positive feedback loop between microglia and the SNS, leading to down-regulation of the SNS hyperactivity and its enhancing influence on microglial activation/proinflammatory functions and the magnitude of autoimmune response. The effects of propranolol are shown to be more prominent in male EAE animals, the phenomenon important as males (like men) are likely to develop clinically more severe disease. Thus, these findings could serve as a firm scientific background for formulation of a new sex-specific immune-intervention strategy for the early phases of MS (characterized by the SNS hyperactivity) exploiting anti-(neuro)inflammatory and immunomodulatory properties of propranolol and other relatively cheap and safe adrenergic drugs with similar therapeutic profile.

Crude Saponin from Platycodon grandiflorum Attenuates Aβ-Induced Neurotoxicity via Antioxidant, Anti-Inflammatory and Anti-Apoptotic Signaling Pathways

Although Platycodon grandiflorum saponins exhibit many beneficial biological effects in various diseases and conditions, how they protect nerve cells against neurodegenerative diseases and Alzheimer’s disease (AD) pathology is unknown. We investigated whether P. grandiflorum crude saponin (PGS) protects neurons from neurodegeneration caused by amyloid beta (Aβ)-induced oxidative stress. Hippocampal neuron HT-22 cells were used in the in vitro experiment, and AD mice (5XFAD mice) were used as the in vivo model. Intracellular reactive oxygen species (ROS) was stained with DCF-DA and assessed using fluorescence microscopy. To elucidate the mechanism underlying neuroprotection, intracellular protein levels were assessed by western blotting. In 5XFAD mice, an animal model of AD, nerve damage recovery due to the induction of Aβ toxicity was evaluated by histological analysis. PGS attenuates Aβ-induced neurotoxicity by inhibiting Aβ-induced reactive oxygen species (ROS) production and apoptosis in HT-22 cells. Furthermore, PGS upregulated Nrf2-mediated antioxidant signaling and downregulated NF-κB-mediated inflammatory signaling. Additionally, PGS inhibited apoptosis by regulating the expression of apoptosis-associated proteins. In addition, PGS ameliorated Aβ-mediated pathologies, leading to AD-associated cognitive decline. Conclusions: Taken together, these findings suggest that PGS inhibits Aβ accumulation in the subiculum and cerebral cortex and attenuates Aβ toxicity-induced nerve damage in vitro and in vivo. Therefore, PGS is a resource for developing AD therapeutics.

Carvedilol induces the antiapoptotic proteins Nrf2 and Bcl2 and inhibits cellular apoptosis in aluminum-induced testicular toxicity in male Wistar rats

The present study was carried out to explore the protective effect of carvedilol (CARV) on aluminum chloride-induced testicular damage in Westar rats. Forty adult male rats, aged 8 weeks, were randomly divided into 4 groups (10 rats each). Group I (control group) received normal saline; whereas group II animals were supplemented with CARV in a dose of 10 mg/kg/day. Group III received AlCl3 (30 mg/kg/day) whereas group IV was co-administered CARV and AlCl3 as the same doses in group II and III respectively. The route of the application was oral gavage for CARV and I.P for AlCl3 for 20 successive days. Exposure of rats to AlCl3 for 20 consecutive days resulted in a significant decrease in serum and testicular superoxide dismutase and catalase activities, serum testosterone level, and sperm count and motility; on the other hand, an increase in nitric oxide, malondialdehyde, aluminum, and serum tumor necrosis factor-alpha levels. Furthermore, histopathological changes in the testis exhibited marked testicular damage. In addition, it revealed a significant up-regulation in the level of the expression for the apoptotic marker; Caspase-3, and down-regulation in antiapoptotic marker Bcl2 and Nrf2 genes. On the other hand, the co-administration of CARV modulated the biochemical parameters, saved sperm count and motility, and the histopathological findings, also, restored the observed changes in Caspase-3, Bcl2, and Nrf2 transcriptional genes. These data suggested that administration of CARV protects against AlCl3 induced testicular oxidative, inflammatory, and apoptosis damage.

Rosuvastatin and low-dose carvedilol combination protects against isoprenaline-induced myocardial infarction in rats: Role of PI3K/Akt/Nrf2/HO-1 signalling

Rosuvastatin has been shown to activate PI3K/Akt/Nrf2/HO-1 pathway, which promotes cell survival in the myocardium. This study investigated the therapeutic benefit of adding rosuvastatin to low-dose carvedilol in protection against myocardial infarction (MI). Rosuvastatin (RSV) and carvedilol (CAR) were given for 7 consecutive days with concurrent administration of two doses of isoprenaline (ISP) on 6th and 7th days to induce MI. Isoprenaline injections caused detrimental alterations in the myocardial architecture and electrocardiogram (ECG) pattern and significantly increased the infarct size, heart index and serum levels of cardiotoxicity markers compared to the control group. ISP induced oxidative damage, inflammatory and apoptotic events and downregulated PI3K/Akt/Nrf2/HO-1 signalling pathway compared to the control values. Treatment with low-dose CAR and/or RSV prevented the ECG and histopathological alterations induced by ISP, and also reduced the infarct size, heart index, serum creatine kinase-MB, cardiac troponin-I and C-reactive protein levels compared to ISP group. CAR and/or RSV treatment restored the activity of superoxide dismutase and total antioxidant capacity with a consequent reduction in lipid peroxides level. Further, they decreased the expression of nuclear factor (NF)-κB (p65) and increased the phosphorylated PI3K and Akt, which may activate the anti-apoptotic signalling as evidenced by the decreased active caspase 3 level. The combination therapy has a more significant effect in the most studied parameters than their monotherapy, which may be because of the activation of PI3K/Akt Nrf2/HO-1 pro-survival signalling pathway. This study highlights the potential benefits of combining RSV with low-dose CAR in case of MI.

Carvedilol Exerts Neuroprotective Effect on Rat Model of Diabetic Neuropathy

Diabetic neuropathy (DN) commonly occurs in diabetics, affecting approximately 50% of both type 1 and 2 diabetic patients. It is a leading cause of non-traumatic amputations. Oxidative stress could play a key role in the pathophysiology of DN. This study aimed to investigate the potential neuroprotective effect of carvedilol on STZ-induced DN in rats. Thirty male Sprague Dawley rats (weighing 200–250 g) were randomly divided into five groups (six/group), where group 1 (negative control) received only the vehicle (0.5% of carboxymethyl cellulose orally 1 ml/kg). DN was induced by a single injection of remaining rats with streptozotocin (STZ; 50 mg/kg, i.p.). After diabetes induction, group 2 served as the diabetic untreated animals; while groups 3 and 4 were treated with carvedilol (1 and 10 mg/kg/d, orally, respectively). Group 5 received a-lipoic acid as a reference neuroprotective (100 mg/kg/d, orally). All treatments were continued for 45 days after diabetes induction, followed by behavioural tests. After sacrificing the animals, dorsal root ganglia, and sciatic nerves were collected for histopathological examination and biochemical assessments. Briefly, STZ administration caused cold allodynia, induced oxidative stress, and increased nerve growth factor (NGF) concentration. Nevertheless, carvedilol improved the behavioural tests, ameliorated the oxidative imbalance as manifested by reducing malondialdehyde, restoring glutathione content, and superoxide dismutase activity. Carvedilol also decreased NGF concentration in DRG homogenate. In conclusion, this study demonstrates the neuroprotective effect of carvedilol in an experimentally induced DN rat model through–at least partly–its antioxidant effect and reduced NGF concentration in DRG.

The Effects of Crinum asiaticum var. japonicum Baker Seeds on Neuroprotection and Antineuroinflammation in Neuronal Cell Lines

Crinum asiaticum var. japonicum Baker is a Korean herbal medicine that is traditionally prescribed for reducing fever and inflammation. In the present study, we investigated if the ethanol extract of C. asiaticum seeds (ECAS) influences the hallmarks of Alzheimer’s disease (AD) pathogenesis. ECAS markedly inhibited the activity of acetylcholinesterase (AChE). Concurrent treatment with hydrogen peroxide (H2O2) and ECAS significantly prevented the neuronal cell death by regulating phosphorylation of cyclic adenosine monophosphate response element-binding protein and p38 mitogen-activated protein kinase. ECAS revealed antineuroinflammatory effects by inhibiting nitric oxide production and suppressing inducible nitric oxide expression in lipopolysaccharide-stimulated BV-2 microglia. Furthermore, the high-performance liquid chromatographic analysis determined lycorine as a standard compound of ECAS. Our data suggest that ECAS has inhibitory effects on AD pathogenesis such as AChE activation, neuronal damage, and neuroinflammation.

Carvedilol Promotes Retinal Ganglion Cell Survival Following Optic Nerve Injury via ASK1-p38 MAPK Pathway

BACKGROUND

Carvedilol, which is considered as a nonselective β-adrenoreceptor blocker, has many pleiotropic activities. It also causes great impact on neuroprotection because of its antioxidant ability, which suggested that carvedilol may be effective in protecting RGCs from increased oxidative stress.

OBJECTIVE

To examine the effects of carvedilol on preventing Retinal Ganglion Cell (RGC) death in a mouse model of Optic Nerve Injury (ONI).

METHODS

C57BL/6J mice were subjected to Optic Nerve Injury (ONI) model and treated with carvedilol or placebo. Histological and morphometric studies were performed; the RGC number, the amount of neurons in the ganglion cell layer and the thickness of the Inner Retinal Layer (IRL) was quantified. The average thickness of Ganglion Cell Complex (GCC) was determined by the Spectral- Domain OCT (SD-OCT) assay. Immunohistochemistry, western blot and quantitative real-time PCR analysis were also applied.

RESULTS

Daily treatment of carvedilol reduced RGC death following ONI, and in vivo retinal imaging revealed that carvedilol can effectively prevent retinal degeneration. The expression of chemokines important for micorglia recruitment was deceased with carvedilol ingestion and the accumulation of retinal microglia is reduced consequently. In addition, the ONI-induced expression of inducible nitric oxide synthase in the retina was inhibited with carvedilol treatment in the retina. We also discovered that carvedilol suppressed ONI-induced activation of Apoptosis Signal-regulating Kinase-1 (ASK1) and p38 Mitogen-Activated Protein Kinase (MAPK) pathway.

CONCLUSION

The results of this study indicate that carvedilol can stimulate neuroprotection and neuroregeneration, and may be useful for treatment of various neurodegenerative diseases.

Quantitative Analysis of 7 Compounds in Diospyros lotus Leaf Extract and Its Biological Effects on Neuroprotection and Antineuroinflammation

Diospyros lotus L. (Ebenaceae) is a deciduous plant that was traditionally used to treat various diseases such as sedation, constipation, and hypertension. However, its effects on Alzheimer’s diseases (AD) have not been reported. We investigated the potent biological effects of D. lotus on AD and performed quantitative analysis of 7 standard compounds in D. lotus leaves. First, two parts leaf and branch of D. lotus were compared to examine the effects on amyloid-β (Aβ) aggregation and oxidative stress. Ethanol extract of D. lotus leaves (EDLL) had higher activities on the Aβ disaggregation and antioxidation compared with ethanol extract of D. lotus branches (EDLB). Second, we have focused on the biological activities of EDLL for neurocellular analyses. In HT22 neuronal cells, EDLL reversed hydrogen peroxide (H2O2)-damaged cell death. In BV-2 microglia, EDLL suppressed lipopolysaccharide-stimulated productions of nitric oxide (NO) and prostaglandin E2. Third, we performed quantitative analyses of 7 standard compounds in D. lotus using high-performance liquid chromatography. Among 7 compounds, myricitrin (44.189 mg/g) was the most abundant compound in EDLL. Myricetin presented the marked inhibitory effect on Aβ aggregation, indicating its potential as a bioactive compound to control Aβ aggregation. Overall, this study suggests that EDLL may be a promising therapeutic agent for AD via Aβ disaggregation, and inhibition of neuronal cell damage and inflammation.

Curcumin and α/β-Adrenergic Antagonists Cotreatment Reverse Liver Cirrhosis in Hamsters: Participation of Nrf-2 and NF-κB

Liver cirrhosis is the result of an uncontrolled fibrogenetic process, due to the activation and subsequent differentiation into myofibroblasts of the hepatic stellate cells (HSC). It is known that HSC express adrenoreceptors (AR), and the use of AR antagonists protects experimental animals from cirrhosis. However, several studies suggest that the toxicity generated by metabolism of these antagonists would hinder its use in cirrhotic patients. In addition, liver fibrosis may be associated with a decrease of the antioxidant response of the nuclear factor erythroid 2-related factor 2 (Nrf-2) and the overregulation of the proinflammatory pathway of nuclear factor kappa B (NF-κB). Therefore, in the present work, the capacity of doxazosin (α1 antagonist), carvedilol (nonselective beta-adrenoceptor blocker with alpha 1-blocking properties), and curcumin (antioxidant and anti-inflammatory compound) to reverse liver cirrhosis and studying the possible modulation of Nrf-2 and NF-κB were evaluated. Hamsters received CCl4 for 20 weeks, and then treatments were immediately administered for 4 weeks more. The individual administration of doxazosin or carvedilol showed less ability to reverse cirrhosis in relation to concomitantly curcumin administration. However, the best effect was the combined effect of doxazosin, carvedilol, and curcumin, reversing liver fibrosis and decreasing the amount of collagen I (Sirius red stain) without affecting the morphology of hepatocytes (hematoxylin and eosin stain), showing normal hepatic function (glucose, albumin, AST, ALT, total bilirubin, and total proteins). In addition, carvedilol treatment and the combination of doxazosin with curcumin increased Nrf-2/NF-κB mRNA ratio and its protein expression in the inflammatory cells in the livers, possibly as another mechanism of hepatoprotection. Therefore, these results suggest for the first time that α/β adrenergic blockers with curcumin completely reverse hepatic damage, possibly as a result of adrenergic antagonism on HSC and conceivably by the increase of Nrf-2/NF-κB mRNA ratio.

Carvedilol abrogates hypoxia-induced oxidative stress and neuroinflammation in microglial BV2 cells

Microglia initially undergo rapid activation in response to injury and stressful stimuli, such as hypoxia. Oxidative stress and the inflammatory response play critical roles in hypoxic-ischemic brain injury. Carvedilol is a β-blocker used to treat high blood pressure and heart failure. In this study, we investigated whether carvedilol had a protective effect against hypoxia-induced oxidative stress and inflammation in microglial BV2 cells. Our results indicate that hypoxic exposure significantly reduced mean cell viability of BV2 microglia, which was significantly restored by carvedilol (10 and 50μM). In addition, carvedilol treatment significantly inhibited the hypoxia-induced increase in reactive oxygen species (ROS) and 4-hydroxy-2-nonenal (4-HNE). Administration of carvedilol significantly inhibited expression of IL-1β, TNF-α, and IL-6 at both the mRNA and protein levels. Mechanistically, we found that hypoxia significantly increased phosphorylation of IKK, IκBα, and NF-κB p65. However, treatment with carvedilol inhibited phosphorylation of these molecules. Notably, hypoxia resulted in a significant nuclear translocation of NF-κB p65, which was inhibited by administration of carvedilol. Luciferase reporter assay results demonstrate that treatment with carvedilol inhibited the hypoxia-induced increase in NF-κB binding activity. These data suggest that carvedilol may be of potential use as a novel therapy against hypoxia or ischemia.

Potential Use of Chemoprotectants against the Toxic Effects of Cyanotoxins: A Review

Cyanobacterial toxins, particularly microcystins (MCs) and cylindrospermopsin (CYN), are responsible for toxic effects in humans and wildlife. In order to counteract or prevent their toxicity, various strategies have been followed, such as the potential application of chemoprotectants. A review of the main substances evaluated for this aim, as well as the doses and their influence on cyanotoxin-induced toxicity, has been performed. A search of the literature shows that research on MCs is much more abundant than research on CYN. Among chemoprotectants, antioxidant compounds are the most extensively studied, probably because it is well known that oxidative stress is one of the toxic mechanisms common to both toxins. In this group, vitamin E seems to have the strongest protectant effect for both cyanotoxins. Transport inhibitors have also been studied in the case of MCs, as CYN cellular uptake is not yet fully elucidated. Further research is needed because systematic studies are lacking. Moreover, more realistic exposure scenarios, including cyanotoxin mixtures and the concomitant use of chemoprotectants, should be considered.

Quantitative Analysis of Psoralea corylifolia Linne and its Neuroprotective and Anti-Neuroinflammatory Effects in HT22 Hippocampal Cells and BV-2 Microglia

The seeds of Psoralea corylifolia L. (P. corylifolia), also known as “Bo-Gol-Zhee” in Korea, are used in a traditional herbal medicine for treating various skin diseases. In the present study, we performed quantitative analyses of the seven standard components of P. corylifolia: psoralen, angelicin, neobavaisoflavone, psoralidin, isobavachalcone, bavachinin, and bakuchiol, using high-performance liquid chromatography. We also investigated the neuroprotective and anti-neuroinflammation effects of P. corylifolia and its standard components in the hippocampal cell line HT22 and microglia cell line BV-2. A 70% ethanol extract of P. corylifolia was prepared and the seven standard components were separated using C-18 analytical columns by gradient solvents with acetonitrile and water, and ultraviolet detection at 215, 225 and 275 nm. The analytical method showed high linearity, with a correlation coefficient of ≥0.9999. The amounts of the standard components ranged from 0.74 to 11.71 mg/g. Among the components, bakuchiol (11.71 mg/g) was the most potent phytochemical component of P. corylifolia. Furthermore, we analyzed the inhibitory effects of the components from P. corylifolia to determine the bioactive compound needed to regulate neuronal cell changes. Angelicin, isobavachalcone, and bakuchiol suppressed lipopolysaccharide (LPS)-stimulated nitric oxide production in LPS-treated BV-2 microglia more significantly than did the other components. In HT22 hippocampal cells, neobavaisoflavone and bakuchiol had more potent inhibitory activity against hydrogen peroxide-induced cell death. Taken together of the quantification and efficacy analyses, bakuchiol appeared to be the most potent bioactive phytochemical component of P. corylifolia for the potential treatment of neurodegenerative diseases.

Effects of L-carnitine against H2O2-induced oxidative stress in grass carp ovary cells (Ctenopharyngodon idellus)

This study was designed in vitro to investigate the effects of L-carnitine against H2O2-induced oxidative stress in a grass carp (Ctenopharyngodon idellus) ovary cell line (GCO). GCO cells were pre-treated with different concentrations of L-carnitine, followed by incubation with 2.5 mM H2O2 for 1 h to induce oxidative damage. The results indicated that adding L-carnitine at concentrations of 0.01-1 mM into the medium for 12 h significantly increased cell viability. Pre-treatment with L-carnitine at concentrations of 0.1-5 mM for 12 h significantly inhibited 2.5 mM H2O2-induced cell viability loss. The significant decreases in the level of reactive oxygen species and cell apoptosis were observed in 0.5 mM L-carnitine group compared to the H2O2 group. Malondialdehyde values of all of the L-carnitine groups were significantly lower than those of the H2O2 group, while total glutathione levels of all of the L-carnitine groups were significantly higher than of the H2O2 group. The activity of antioxidant enzymes, such as total superoxide dismutase (0.1 and 0.5 mM L-carnitine), catalase (0.5 mM L-carnitine) and γ-glutamyl cysteine synthetase (0.5 and 1 mM L-carnitine), was significantly increased. In addition, pre-treatment of L-carnitine in GCO cells exposed to 2.5 mM H2O2 significantly increased the mRNA expression of copper, zinc superoxide dismutase, catalase (0.5 mM L-carnitine), glutamate cysteine ligase catalytic subunit (0.1-1 mM) and glutathione peroxidase (0.1 mM L-carnitine). In conclusion, L-carnitine promotes GCO cell growth and improves antioxidant function, it plays a protective role against oxidative stress induced by H2O2 in GCO cells, and the appropriate supplemental amount of L-carnitine is 0.1-1 mM.

Carvedilol protects bone marrow stem cells against hydrogen peroxide-induced cell death via PI3K-AKT pathway

Carvedilol, a nonselective β-adrenergic receptor blocker, has been reported to exert potent anti-oxidative activities. In the present study, we aimed to investigate the effects of carvedilol against hydrogen peroxide (H2O2)-induced bone marrow-derived mesenchymal stem cells (BMSCs) death, which imitate the microenvironment surrounding transplanted cells in the injured spinal cord in vitro. Carvedilol significantly reduced H2O2-induced reactive oxygen species production, apoptosis and subsequent cell death. LY294002, the PI3K inhibitor, blocked the protective effects and up-regulation of Akt phosphorylation of carvedilol. Together, our results showed that carvedilol protects H2O2-induced BMSCs cell death partly through PI3K-Akt pathway, suggesting carvedilol could be used in combination with BMSCs for the treatment of spinal cord injury by improving the cell survival and oxidative stress microenvironments.

Low Doses of Camptothecin Induced Hormetic and Neuroprotective Effects in PC12 Cells

Hormetic response is an adaptive mechanism for a cell or organism surviving in an unfavorable environment. It has been an intriguing subject of researches covering a broad range of biological and medical disciplines, in which the underlying significance and molecular mechanisms are under intensive investigation. In the present study, we demonstrated that topoisomerase I inhibitor camptothecin (CPT), a potent anticancer agent, induced an obvious hormetic response in rat pheochromocytoma PC12 cells. Camptothecin inhibited PC12 cell growth at relative high doses as generally acknowledged while stimulated the cell growth by as much as 39% at low doses. Moreover, low doses of CPT protected the cells from hydrogen peroxide (H₂O₂)-induced cell death. Phosphoinositide 3-kinase (PI3K)/Akt and nuclear factor-E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathways were reported playing pivotal roles in protecting cells from oxidative stress. We observed that these 2 pathways were upregulated by low doses of CPT, as evidenced by increased levels of phosphorylated PI3K, phosphorylated Akt, phosphorylated mammalian target of rapamycin, Nrf2, and HO-1; and abolishment of the growth-promoting and neuroprotective effects of CPT by LY294002, a PI3K inhibitor. These results suggest that the hormetic and neuroprotective effects of CPT at low doses on PC12 cells were attributable, at least partially, to upregulated PI3K/Akt and Nrf2/HO-1 pathways.

Preclinical Evidences for an Antimanic Effect of Carvedilol

Oxidative imbalance, alterations in brain-derived neurotrophic factor (BDNF), and mitochondrial dysfunction are implicated in bipolar disorder (BD) pathophysiology and comorbidities, for example, cardiovascular conditions. Carvedilol (CVD), a nonselective beta-blocker widely used for the treatment of hypertension, presents antioxidant and mitochondrial stabilizing properties. Thus, we hypothesized that CVD would prevent and/or reverse mania-like behavioral and neurochemical alterations induced by lisdexamfetamine dimesylate (LDX). To do this, male Wistar rats were submitted to two different protocols, namely, prevention and reversal. In the prevention treatment the rats received daily oral administration (mg/kg) of CVD (2.5, 5 or 7.5), saline, valproate (VAL200), or the combination of CVD5 + VAL100 for 7 days. From the 8th to 14th day LDX was added. In the reversal protocol LDX was administered for 7 days with the drugs being added from the 8th to 14th day of treatment. Two hours after the last administration the behavioral (open field and social interaction) and neurochemical (reduced glutathione, lipid peroxidation, and BDNF) determinations were performed. The results showed that CVD prevented and reversed the behavioral and neurochemical alterations induced by LDX. The administration of CVD5 + VAL100 potentiated the effect of VAL200 alone. Taken together these results demonstrate a possible antimanic effect of CVD in this preclinical model.

Dual targeting of TNF-α and free radical toxic stress as a promising strategy to manage experimental polycystic ovary

CONTEXT

It is now clear that oxidative stress (OS) and chronic low-grade inflammation are two main pathways involved in polycystic ovary syndrome (PCOS) pathogenesis. Therefore, simultaneous targeting of these pathways by means of carvedilol and Semelil (ANGIPARS™), as established medicines with dual anti-cytokine and anti-oxidant potential may be a therapeutic alternative approach to the current treatments.

OBJECTIVE

The objective of this study is to study the protective effects of carvedilol and ANGIPARS™ on inflammatory and oxidative response in hyperandrogenism-induced polycystic ovary (PCO).

MATERIALS AND METHODS

The murine model of PCO was induced by letrozole (1 mg/kg/d; orally) and effective doses of carvedilol (10 mg/kg/d; orally) and ANGIPARS™ (2.1 mg/kg/d; orally) were administrated for 21 d in PCO and non-PCO healthy rats. Ovarian folliculogenesis, sex hormones concentrations, OS, inflammatory, and metabolic biomarkers were assessed in serum and ovaries.

RESULTS

PCO rats exhibited ovarian cystogenesis which was preserved by the application of carvedilol and ANGIPARS™. In comparison with controls, decreased level of the total antioxidant power (TAP) and higher levels of reactive oxygen species (ROS) and lipid peroxidation (LPO) in serum and ovaries (2.41 ± 0.67 versus 0.72 ± 0.11; and 0.17 ± 0.04 versus 0.05 ± 0.01; 5.48 ± 1.30 versus 10.56 ± 0.77; and 7.06 ± 1.94 versus 17.98 ± 0.98; p < 0.05, respectively) were detected in PCO rats. Moreover, the PCO rats exhibited hyperandrogenism due to a 3.7-fold increase in serum testosterone concentration (35.04 ± 3.17 versus 131.09 ± 13.24; p < 0.05) along with a 2.98-fold decrease in serum progesterone (6.19 ± 0.40 versus 18.50 ± 1.03; p < 0.05) and 5.2-fold decrease in serum estradiol (9.30 ± 0.61 versus 48.3 ± 2.10; p < 0.05) when compared with those of the control group. However, similar to the control group, normal levels of OS markers and sex hormones were detected in ANGIPARS™ and carvedilol co-treated PCO rats. Besides, when compared with controls, increased levels of TNF-α (770.75 ± 42.06 versus 477.14 ± 28.77; p < 0.05) and insulin (1.27 ± 0.10 versus 0.36 ± 0.05; p < 0.05) in PCO rats were significantly inhibited by carvedilol and ANGIPARS™ co-treatment.

DISCUSSION AND CONCLUSION

We evidenced the beneficial effects of carvedilol and ANGIPARS™ in PCO, which underpin the new alternative approach in using these kinds of medicines in female reproductive disorders.

Cloning, expression, and purification of cold inducible RNA-binding protein and its neuroprotective mechanism of action

BACKGROUND

Cold-inducible RNA-binding protein (CIRP) is induced in response to hypothermia, where it exerts neuroprotective effects. Our preliminary studies revealed that it inhibits H2O2-induced apoptosis in rat neurons. In the current study, we report effective expression and purification approaches for the synthesis of CIRP, and assess its potential protective effects against oxidative stress.

METHODS

CIRP-encoding was expressed using the prokaryotic expression system pGEX-4T-1, and SP-Sepharose and Sephacryl S-200 columns were used to purify rCIRP. To mimic ischemia/reperfusion injury-associated oxidative stress, neuro2a cells (N2a) were pre-treated with rCIRP for 2h, followed by hydrogen peroxide (H2O2 60 μmol/ml) for 24h. Cell viability was then quantified using an MTT assay. In addition, western blotting was performed to measure the cell cycle related signal transduction pathways.

RESULTS

N2a cells exhibited decreased viability following H2O2 treatment, whereas rCIRP significantly improved viability following H2O2 treatment. CIRP also accelerated cell cycle progression from S to G2/M phase in cultured mouse neuroblastoma cells. In addition, CIRP increased levels of p-ERK and p-Akt, and also re-activated the cell cycle-related protein cyclin D1 and c-Myc. These results suggest that CIRP activated the Akt and ERK signal transduction pathways in N2a cells.

CONCLUSIONS

Our findings suggest that CIRP could exert protective effects against oxidative stress, and that it might be a novel neuroprotective agent.

Prevention of skin carcinogenesis by the β-blocker carvedilol

The stress-related catecholamine hormones and the α- and β-adrenergic receptors (α- and β-AR) may affect carcinogenesis. The β-AR GRK/β-arrestin biased agonist carvedilol can induce β-AR-mediated transactivation of the EGFR. The initial purpose of this study was to determine whether carvedilol, through activation of EGFR, can promote cancer. Carvedilol failed to promote anchorage-independent growth of JB6 P(+) cells, a skin cell model used to study tumor promotion. However, at nontoxic concentrations, carvedilol dose dependently inhibited EGF-induced malignant transformation of JB6 P(+) cells, suggesting that carvedilol has chemopreventive activity against skin cancer. Such effect was not observed for the β-AR agonist isoproterenol and the β-AR antagonist atenolol. Gene expression, receptor binding, and functional studies indicate that JB6 P(+) cells only express β2-ARs. Carvedilol, but not atenolol, inhibited EGF-mediated activator protein-1 (AP-1) activation. A topical 7,12-dimethylbenz(α)anthracene (DMBA)-induced skin hyperplasia model in SENCAR mice was utilized to determine the in vivo cancer preventative activity of carvedilol. Both topical and oral carvedilol treatment inhibited DMBA-induced epidermal hyperplasia (P < 0.05) and reduced H-ras mutations; topical treatment being the most potent. However, in models of established cancer, carvedilol had modest to no inhibitory effect on tumor growth of human lung cancer A549 cells in vitro and in vivo. In conclusion, these results suggest that the cardiovascular drug carvedilol may be repurposed for skin cancer chemoprevention, but may not be an effective treatment of established tumors. More broadly, this study suggests that β-ARs may serve as a novel target for cancer prevention.