An adenoviral vector encoded with the GPx-1 gene attenuates memory impairments induced by ß-amyloid (1-42) in GPx-1 KO mice via activation of M1 mAChR-mediated signalling.

In the present study, we examined whether glutathione peroxidase-1 (GPx-1), a major H2O2 scavenger in the brain, affects memory deficits induced by Aß (1-42) in mice. Treatment with 400 pmol/5 µl Aß (1-42) (i.c.v.) resulted in a reduction of GPx-1 expression in wild-type (WT) mice. An Aß (1-42)-induced reduction in acetylcholine (ACh) level was observed in the hippocampus. Treatment with Aß (1-42) consistently resulted in reduced expression and activity of choline acetyltransferase (ChAT) and in an increase in expression and activity of acetylcholinesterase (AChE). Upon examining each of the muscarinic acetylcholine receptors (mAChRs) and nicotinic AChRs, we noted that Aß (1-42) treatment selectively reduced the levels of M1 mAChR. In addition, Aß (1-42) induced a significant reduction in phospho-cAMP response element-binding protein (p-CREB) and brain-derived neurotrophic factor (BDNF) expression. The cholinergic impairments induced by Aß (1-42) were more pronounced in GPx-1 knockout mice than in WT mice. Importantly, an adenoviral vector encoded with the GPx-1 gene (Ad-GPx-1) significantly rescued Aß (1-42)-induced cholinergic impairments in GPx-1 knockout mice. In addition, M1 mAChR antagonist dicyclomine significantly counteracted Ad-GPx-1-mediated increases in p-CREB and BDNF expression, as well as memory-enhancing effects in GPx-1 knockout mice, thus indicating that M1 mAChR might be a critical mediator for the rescue effects of Ad-GPx-1. Combined, our results suggest that GPx-1 gene protected against Aß (1-42)-induced memory impairments via activation of M1 mAChR-dependent CREB/BDNF signalling.

5-HT2A receptor-mediated PKCδ phosphorylation is critical for serotonergic impairments induced by p-chloroamphetamine in mice.

p-Chloroamphetamine (PCA), an amphetamine derivative, has been shown to induce serotonergic toxicity. However, the precise mechanism of serotonergic toxicity induced by PCA remains unclear. In this study, PCA treatment (20 mg/kg, i.p.) did not significantly change 5-HT1A receptor gene expression, but significantly increased 5-HT2A receptor gene expression. Furthermore, 5-HT2A receptor antagonist MDL11939, but not 5-HT1A receptor antagonist WAY100635, significantly attenuated PCA-induced serotonergic impairments. We investigated whether PCA activated a specific isoform of protein kinase C (PKC), since previous evidence indicated the involvement of PKC in neurotoxicity induced by amphetamines. We observed that PCA treatment significantly increased the expression levels of PKCδ among all PKC isoforms. MDL11939 treatment significantly attenuated PCA-induced phosphorylation of PKCδ. However, PCA-induced increase in 5-HT2A receptor gene expression was not altered by rottlerin (a pharmacological inhibitor of PKCδ) in mice, suggesting that 5-HT2A receptor is an upstream molecule for the activation of PKCδ. Rottlerin or PKCδ knockout significantly attenuated serotonergic behaviors. However, MDL11939 did not show any additional effects against the attenuation caused by PKCδ knockout in mice, suggesting that PKCδ gene is a molecular target for 5-HT2A receptor-mediated serotonergic effects. Our results suggest that 5-HT2A receptor mediates PCA-induced serotonergic impairments via activation of PKC.δ.

Glutathione peroxidase-1 overexpressing transgenic mice are protected from cocaine-induced drug dependence.

Converging evidence has demonstrated that oxidative burdens are associated with drug dependence induced by psychostimulants. Here, we investigated whether oxidative stress directly mediates conditioned place preference and behavioral sensitization (drug dependence) induced by cocaine and whether glutathione peroxidase-1 (GPx-1), a major GPx, modulates cocaine-induced psychotoxic changes in mice. Cocaine-induced drug dependence was followed by increases in c-Fos-immunoreactivity (c-Fos-IR) in the nucleus accumbens. Simultaneously, cocaine significantly increased oxidative parameters and nuclear factor κB (NFκB) activity (i.e. nuclear translocation and DNA binding activity) in the striatum (including nucleus accumbens). Genetic depletion of GPx-1 made mice susceptible to drug dependence induced by cocaine in mice, while genetic overexpression of GPx-1 protected the mice from drug dependence. Pyrrolidine dithiocarbamate (PDTC), a NFκB inhibitor, significantly attenuated the sensitivity induced by the genetic depletion of GPx-1 in mice. However, PDTC did not exhibit any additive effects against the protection afforded by the genetic overexpression of GPx-1. Our results suggest that drug dependence induced by cocaine requires oxidative stress and NFκB activation, and that the GPx-1 gene is a potential protective factor against cocaine-induced drug dependence through positive modulation of NFκB.

P53 knockout mice are protected from cocaine-induced kindling behaviors via inhibiting mitochondrial oxidative burdens, mitochondrial dysfunction, and proapoptotic changes.

Previously we demonstrated that p53 mediates dopaminergic neurotoxicity via inducing mitochondrial burdens and proapoptotsis. However, little is known about the role of p53 in the excitotoxicity induced by psychostimulant, such as cocaine. Cocaine-induced kindling (convulsive) behaviors significantly increased p53 expression in the brain. Cocaine-induced p53 expression was more pronounced in hippocampus than in striatum or prefrontal cortex. Genetic depletion of p53 significantly attenuated cocaine-induced convulsive behaviors, followed by c-Fos immunoreactivity, and oxidative burdens in the hippocampus of mice. The antioxidant potentials mediated by genetic depletion of p53 were more pronounced in the mitochondrial-than cytosolic-fraction. Depletion of p53 significantly attenuated the changes in mitochondrial transmembrane potential, intramitochondrial Ca2+ level, and mitochondrial oxidative burdens induced by cocaine. Consistently, depletion of p53 significantly inhibited mitochondrial p53 translocation, and cleaved-PKCδ induced by cocaine. In addition, depletion of p53 protected from cytosolic cytochrome c release, and pro-apoptotic changes induced by cocaine. Importantly, the protective/anticonvulsant potentials by genetic depletion of p53 were comparable to those by pifithrin-µ (PFT), a p53 inhibitor. Our results suggest that depletion of p53 offers anticonvulsive and neuroprotective potentials mainly via attenuating mitochondrial oxidative burdens, mitochondrial dysfunction, and pro-apoptotic signalings against cocaine-induced convulsive neurotoxicity.

Glutathione peroxidase-1 overexpressing transgenic mice are protected from neurotoxicity induced by microcystin-leucine-arginine.

Although it has been well-recognized that microcystin-leucine-arginine (MCLR), the most common form of microcystins, induces neurotoxicity, little is currently known about the underlying mechanism for this neurotoxicity. Here, we found that MCLR (10 ng/µL/mouse, i.c.v.) induces significant neuronal loss in the hippocampus of mice. MCLR-induced neurotoxicity was accompanied by oxidative stress, as shown by a significant increase in the level of 4-hydroxynonenal, protein carbonyl, and reactive oxygen species (ROS). Superoxide dismutase-1 (SOD-1) activity was significantly increased, but glutathione peroxidase (GPx) level was significantly decreased following MCLR insult. In addition, MCLR significantly inhibited GSH/GSSG ratio, and significantly induced NFκB DNA binding activity. Because reduced activity of GPx appeared to be critical for the imbalance between activities of SODs and GPx, we utilized GPx-1 overexpressing transgenic mice to ascertain the role of GPx-1 in this neurotoxicity. Genetic overexpression of GPx-1 or NFκB inhibitor pyrrolidine dithiocarbamate (PDTC) significantly attenuated MCLR-induced hippocampal neuronal loss in mice. However, PDTC did not exert any additive effect on neuroprotection mediated by GPx-1 overexpression, indicating that NFκB is a neurotoxic target of MCLR. Combined, these results suggest that MCLR-induced neurotoxicity requires oxidative stress associated with failure in compensatory induction of GPx, possibly through activation of the transcription factor NFκB.

Evaluation of medication dosing errors in elderly patients with renal impairment
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OBJECTIVE: The administration of the usual dosage of medication in elderly patients with renal impairment can cause adverse drug reactions due to patients' decreased renal function. Using retrospective prescription analysis, in a teaching hospital, this study aimed to evaluate medication dosing errors in elderly patients with renal impairment and the risk factors for these dosing errors. MATERIALS AND METHODS: This retrospective study included elderly patients with a creatinine clearance of 59 mL/min or less who were hospitalized in a teaching hospital between July 1, 2015, and September 30, 2015. Data including the patients' age, gender, weight, serum creatinine, duration of hospital stay, and discharge prescriptions were obtained from electronic medical records. Patients with dosing errors were identified, and the risk factors for the dosing errors were statistically analyzed. RESULTS: Out of 497 patients, 164 (33%) had evidence of dosing errors. All metformin prescriptions (n = 38) were associated with dosing errors (100%), and trimetazidine was prescribed 11 times in cases where it was contraindicated (31%). The following were confirmed to be statistically significant risk factors that increased the likelihood of the dosing errors: the patient's age (odds ratio (OR): 1.050, 95% confidence interval (CI): 1.011 - 1.092), the number of drugs prescribed per patient (OR: 1.106; 95% CI: 1.012 - 1.210), and the number of drugs requiring dosing adjustments in patients with renal impairment (OR: 1.996; 95% CI: 1.614 - 2.468). CONCLUSION: There was a considerable rate of dosing errors in hospitalized elderly patients with renal impairment. It is necessary for healthcare professionals to make appropriate dosage adjustments in elderly patients with renal impairment to improve the outcomes of pharmacotherapy and patients' quality of life.
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Genetic overexpression of glutathione peroxidase-1 attenuates microcystin-leucine-arginine-induced memory impairment in mice.

Microcystin-leucine-arginine (MCLR) is the most common form of microcystins, which are environmental toxins produced by cyanobacteria, and its hepatotoxicity has been well-documented. However, the neurotoxic potential of MCLR remains to be further elucidated. In the present study, we investigated whether intracerebroventricular (i.c.v.) infusion of MCLR induces mortality and neuronal loss in the hippocampus of mice. Because we found that MCLR impairs memory function in the hippocampus at a low dose (4 ng/µl/mouse, i.c.v.) without a significant neuronal loss, we focused on this dose for further analyses. Results showed that MCLR (4 ng/µl/mouse, i.c.v.) significantly increased oxidative stress (i.e., malondialdehyde, protein carbonyl, and synaptosomal ROS) in the hippocampus. In addition, MCLR significantly increased superoxide dismutase (SOD) activity without corresponding induction of glutathione peroxidase (GPx) activity, and thus led to significant decrease in the ratio of GPx/SODs activity. The GSH/GSSG ratio was also significantly reduced after MCLR treatment. GPx-1 overexpressing transgenic mice (GPx-1 Tg) were significantly protected from MCLR-induced memory impairment and oxidative stress. The DNA binding activity of nuclear factor erythroid-derived 2-related factor 2 (Nrf2) in these mice was significantly enhanced, and the ratios of GPx/SODs activity and GSH/GSSG returned to near control levels in the hippocampus. Importantly, memory function exhibited a significant positive correlation with the ratios of GPx/SODs activity and GSH/GSSG in the hippocampus of MCLR-treated non-transgenic (non-Tg)- and GPx-1 Tg-mice. Combined, our results suggest that MCLR induces oxidative stress and memory impairment without significant neuronal loss, and that GPx-1 gene constitutes an important protectant against MCLR-induced memory impairment and oxidative stress via maintaining antioxidant defense system homeostasis, possibly through the induction of Nrf2 transcription factor.

Exposure to far-infrared ray attenuates methamphetamine-induced impairment in recognition memory through inhibition of protein kinase C δ in male mice: Comparison with the antipsychotic clozapine.

We have previously demonstrated that repeated treatment with methamphetamine (MA) results in a recognition memory impairment via upregulation of protein kinase C (PKC) δ and downregulation of the glutathione peroxidase-1 (GPx-1)-dependent antioxidant system. We also demonstrated that far-infrared ray (FIR) attenuates acute restraint stress via induction of the GPx-1 gene. Herein, we investigated whether exposure to FIR modulates MA-induced recognition memory impairment in male mice, and whether cognitive potentials mediated by FIR require modulation of the PKCδ gene, extracellular signal-regulated kinase (ERK) 1/2, and glutathione-dependent system. Repeated treatment with MA significantly increased PKCδ expression and its phosphorylation out of PKC isoenzymes (i.e., PKCα, PKCßI, PKCßII, PKCζ, and PKCδ expression) in the prefrontal cortex of mice. Exposure to FIR significantly attenuated MA-induced increase in phospho-PKCδ and decrease in phospho-ERK 1/2. In addition, FIR further facilitated the nuclear factor E2-related factor 2 (Nrf2)-dependent glutathione synthetic system. Moreover, L-buthionine-(S, R)-sulfoximine, an inhibitor of glutathione synthesis, counteracted the FIR-mediated phospho-ERK 1/2 induction and memory-enhancing activity against MA insult. More important, positive effects of FIR are comparable to those of genetic depletion of PKCδ or the antipsychotic clozapine. Our results indicate that FIR protects against MA-induced memory impairment via activations of the Nrf2-dependent glutathione synthetic system, and ERK 1/2 signaling by inhibition of the PKCδ gene.

Role of dopamine D1 receptor in 3-fluoromethamphetamine-induced neurotoxicity in mice.

3-Fluoromethamphetamine (3-FMA) is an illegal designer drug of methamphetamine (MA) derivative. Up to date, little is known about the neurotoxic potential of 3-FMA. In the present study, we investigated the role of dopamine receptors in neurotoxicity induced by 3-FMA in comparison with MA (35 mg/kg, i.p.) as a control drug. Here we found that 3-FMA (40, 60 or 80 mg/kg, i.p.) produced mortality in a dose-dependent manner in mice. Treatment with 3-FMA (40 mg/kg, i.p.) resulted in significant hyperthermia, oxidative stress and microgliosis (microglial differentiation into M1 phenotype) followed by pro-apoptotic changes and the induction of terminal deoxynucleotidyl transferase dUDP nick end labeling (TUNEL)-positive cells. Moreover, 3-FMA significantly produced dopaminergic impairments [i.e., increase in dopamine (DA) turnover rate and decreases in DA level, and in the expression of tyrosine hydroxylase (TH), dopamine transporter (DAT), and vesicular monoamine transporter 2 (VMAT-2)] with behavioral impairments. These dopaminergic neurotoxic effects of 3-FMA were comparable to those of MA. SCH23390, a dopamine D1 receptor antagonist, but not sulpiride, a dopamine D2 receptor antagonist significantly attenuated 3-FMA-induced neurotoxicity. Although both SCH23390 and sulpiride attenuated MA-induced dopaminergic neurotoxicity, sulpiride is more effective than SCH23390 on the dopaminergic neurotoxicity. Interestingly, SCH23390 treatment positively modulated 3-FMA-induced microglial activation (i.e., SCH23390 inhibited M1 phenotype from 3-FMA insult, but activated M2 phenotype). Therefore, our results suggest that the activation of dopamine D1 receptor is critical to 3-FMA-induced neurotoxicity, while both dopamine D1 and D2 receptors (dopamine D2 receptor > dopamine D1 receptor) mediate MA-induced dopaminergic neurotoxicity.

Blockade of platelet-activating factor receptor attenuates abnormal behaviors induced by phencyclidine in mice through down-regulation of NF-κB.

Accumulating evidence suggests that neuroinflammation is one of the important etiologic factors of abusive and neuropsychiatric disorders. Platelet-activating factor (PAF) is potent proinflammatory lipid mediat1or and plays a pivotal role in neuroinflammatory disorders through the specific PAF receptor (PAF-R). Phencyclidine (PCP) induces a psychotomimetic state that closely resembles schizophrenia. Here, we investigated the role of PAF-R in the abnormal behaviors induced by PCP in mice. Repeated treatment with PCP resulted in a significant increase in PAF-R gene expression in the prefrontal cortex (PFC) and in the hippocampus. This increase was more pronounced in the PFC than hippocampus. Treatment with PCP resulted in a significant increase in nuclear translocation of the nuclear factor kappa beta (NF-κB) p65 and DNA binding activity, indicating that the proinflammatory molecule NF-κB was increased through up-regulation of PAF-R. Consistently, NF-κB activation was significantly protected by the PAF-R antagonist, ginkgolide B (Gink B), in PAF-R knockout mice and by the NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC). In addition, PCP-induced abnormal behaviors (i.e., reduced sociability, depression, cognitive impairment, and behavioral sensitization) were significantly attenuated by Gink B, in PAF-R knockout mice, and by PDTC. Importantly, PDTC did not significantly alter the attenuations observed in Gink B-treated mice or PAF-R knockout mice, indicating that NF-κB is a critical target for neuropsychotoxic modulation of PAF-R. Therefore, the results suggest that PAF-R mediates PCP-induced neuropsychotoxicity via a NF-κB-dependent mechanism, and that up-regulation of PAF-R may be associated with schizophrenia-like behavior in animal models.

Ginsenoside Re protects against phencyclidine-induced behavioral changes and mitochondrial dysfunction via interactive modulation of glutathione peroxidase-1 and NADPH oxidase in the dorsolateral cortex of mice.

We investigated whether ginsenoside Re (Re) modulates phencyclidine (PCP)-induced sociability deficits and recognition memory impairments to extend our recent finding. We examined the role of GPx-1 gene in the pharmacological activity of Re against mitochondrial dysfunction induced by PCP in the dorsolateral cortex of mice. Since mitochondrial oxidative stress activates NADPH oxidase (PHOX), we applied PHOX inhibitor apocynin for evaluating interactive modulation between GPx-1 and PHOX against PCP neurotoxicity. Sociability deficits and recognition memory impairments induced by PCP were more pronounced in GPx-1 knockout (KO) than in wild type (WT) mice. PCP-induced mitochondrial oxidative stress, mitochondrial dysfunction, and membrane translocation of p47phox were more evident in GPx-1 KO than in WT. Re treatment significantly attenuated PCP-induced neurotoxic changes. Re also significantly attenuated PCP-induced sociability deficits and recognition memory impairments. The attenuation by Re was comparable to that by apocynin. The attenuation was more obvious in GPx-1 KO than in WT. Importantly, apocynin did not show any additional positive effects on the neuroprotective activity of Re, indicating that PHOX is a molecular target for therapeutic activity of Re. Our results suggest that Re requires interactive modulation between GPx activity and PHOX (p47phox) to exhibit neuroprotective potentials against PCP insult.

Ginsenoside Re Protects Trimethyltin-Induced Neurotoxicity via Activation of IL-6-Mediated Phosphoinositol 3-Kinase/Akt Signaling in Mice.

Ginseng (Panax ginseng), an herbal medicine, has been used to prevent neurodegenerative disorders. Ginsenosides (e.g., Re, Rb1, or Rg1) were obtained from Korean mountain cultivated ginseng. The anticonvulsant activity of ginsenoside Re (20 mg/kg/day × 3) against trimethyltin (TMT) insult was the most pronounced out of ginsenosides (e.g., Re, Rb1, and Rg1). Re itself did not significantly alter tumor necrosis factor-α (TNF-α), interferon-ϒ (IFN-ϒ), and interleukin-1ß (IL-1ß) expression, however, it significantly increases the interleukin-6 (IL-6) expression. In addition, Re attenuated the TMT-induced decreases in IL-6 protein level. Therefore, IL-6 knockout (-/-) mice were employed to investigate whether Re requires IL-6-dependent neuroprotective activity against TMT toxicity. Re significantly attenuated TMT-induced lipid peroxidation, protein peroxidation, and reactive oxygen species in the hippocampus. Re-mediated antioxidant effects were more pronounced in IL-6 (-/-) mice than in WT mice. Consistently, TMT-induced increase in c-Fos-immunoreactivity (c-Fos-IR), TUNEL-positive cells, and nuclear chromatin clumping in the dentate gyrus of the hippocampus were significantly attenuated by Re. Furthermore, Re attenuated TMT-induced proapoptotic changes. Protective potentials by Re were comparable to those by recombinant IL-6 protein (rIL-6) against TMT-insult in IL-6 (-/-) mice. Moreover, treatment with a phosphoinositol 3-kinase (PI3K) inhibitor, LY294002 (1.6 µg, i.c.v) counteracted the protective potential mediated by Re or rIL-6 against TMT insult. The results suggest that ginsenoside Re requires IL-6-dependent PI3K/Akt signaling for its protective potential against TMT-induced neurotoxicity.

Treatment with Mountain-Cultivated Ginseng Alleviates Trimethyltin-Induced Cognitive Impairments in Mice via IL-6-Dependent JAK2/STAT3/ERK Signaling.

Panax ginseng is the most widely used herbal medicine for improving cognitive functions. The pharmacological activity and underlying mechanisms of mountain-cultivated ginseng, however, have yet to be clearly elucidated, in particular, against trimethyltin-induced cognitive dysfunction. We previously reported that interleukin-6 plays a protective role against trimethyltin-induced cognitive dysfunction. Because of this, we have implemented a study system that uses interleukin-6 null (-/-) and wild-type mice. Interestingly, mountain-cultivated ginseng significantly upregulated interleukin-6 expression. With this study, we sought to determine whether the interleukin-6-dependent modulation of the Janus kinase 2/signal transducer activator of transcription 3 and extracellular signal-regulated kinase signaling network is also associated with the pharmacological activity of mountain-cultivated ginseng against trimethyltin-induced cognitive dysfunction. Trimethyltin treatment (2.4 mg/kg, intraperitoneal) causes the downregulation of Janus kinase 2/signal transducer activator of transcription 3, extracellular signal-regulated kinase signaling, and impairment of the cholinergic system. We found that mountain-cultivated ginseng treatment (50 mg/kg, intraperitoneal) significantly attenuated cognitive impairment normally induced by trimethyltin by upregulating p-Janus kinase 2/signal transducer activator of transcription 3, p-extracellular signal-regulated kinase signaling, and the cholinergic system. Trimethyltin-induced cognitive impairments were more pronounced in interleukin-6 (-/-) mice than wild-type mice, and they were markedly reduced by treatment with either mountain-cultivated ginseng or recombinant interleukin-6 protein (6 ng, intracerebroventricular). Additionally, treatment with either AG490 (20 mg/kg, intraperitoneal), a Janus kinase 2/signal transducer activator of transcription 3 inhibitor, or U0126 (2 µg/head, intracerebroventricular), an extracellular signal-regulated kinase inhibitor, reversed the effects of mountain-cultivated ginseng treatment. The effects of mountain-cultivated ginseng treatment were comparable to those of recombinant interleukin-6 protein in interleukin-6 (-/-) mice. Our results, therefore, suggest that mountain-cultivated ginseng acts through interleukin-6-dependent activation of Janus kinase 2/signal transducer activator of transcription 3/extracellular signal-regulated kinase signaling in order to reverse cognitive impairment caused by trimethyltin treatment.

Evaluation of the effects and adverse drug reactions of low-dose dexamethasone premedication with weekly docetaxel.

PURPOSE: A weekly docetaxel regimen had comparable efficacy with a tri-weekly schedule and caused significantly less severe neutropenia and febrile neutropenia. Therefore, a weekly docetaxel regimen has become increasingly common in cancer treatment. Premedication with corticosteroids can effectively prevent or reduce the severity of hypersensitivity and fluid retention. However, no recommended steroid dosage for a weekly docetaxel regimen has been established to date. The aim of this study is to compare the efficacy and complications of two different weekly docetaxel premedication protocols. METHODS: We retrospectively compared the hypersensitivity, hyperglycemia, and infection incidence associated with two weekly docetaxel premedication protocols. The control group (dexamethasone 10 mg intravenously and 4 mg orally every 12 h for four doses, starting 1 h before docetaxel administration) patients started weekly docetaxel chemotherapy between May 2012 and April 2013 at Seoul National University Hospital, and the experimental group (dexamethasone 10 mg intravenously 1 h prior to each docetaxel administration) patients started weekly docetaxel chemotherapy between May 2013 and April 2014. RESULTS: In total, 109 patients in the control group and 97 patients in the experimental group were included in this study, and there were no statistically significant differences in baseline characteristics between the two groups. The incidence of hypersensitivity and hyperglycemia were similar, but infections were observed significantly less in the experimental group (p = 0.020, OR = 0.408, 0.0190-0.0879). CONCLUSIONS: A low-dose dexamethasone premedication protocol has comparable efficacy in the prevention of docetaxel hypersensitivity with fewer infection complications. Therefore, we recommend a low-dose dexamethasone premedication protocol for weekly docetaxel regimens.

Genetic depletion of glutathione peroxidase-1 potentiates nephrotoxicity induced by multiple doses of cocaine via activation of angiotensin II AT1 receptor.

We investigated the possible roles of angiotensin II type 1 receptor (AT1R) and oxidative stress responsive nuclear factor κB (NFκB) in renal damage caused by multiple doses of cocaine in glutathione peroxidase (GPx)-1 gene-depleted mice. Treatment with cocaine resulted in significant increases in malondialdehyde, protein carbonyl, and pro-apoptotic Bax expression and decreases in the ratio of glutathione (GSH) and its oxidized form (GSSG), GSH-dependent enzymes, and anti-apoptotic factors in the kidney. These alterations were more pronounced in GPx-1 knockout (-/-) mice than in wild type (WT) mice. Notably, the AT1R antagonist losartan protected against the renal toxicity induced by cocaine, whereas the NFκB inhibitor pyrrolidine dithiocarbamate was not protective. The toxicity was more pronounced in GPx-1 (-/-) mice than in WT mice. The protective effect afforded by losartan against cocaine toxicity appeared to be more sensitive in GPx-1 (-/-) mice than that in WT mice. These losartan-mediated protective effects were inhibited by the phosphatidyl-inositol-3-kinase (PI3K) inhibitor LY294002, indicating that losartan provides significant protection from cocaine-induced renal toxicity through PI3K/Akt signaling. Our results suggest that genetic inhibition of GPx-1 potentiates cocaine-induced renal damage via activation of AT1R by inhibition of PI3K-Akt signaling, and that AT1R can be a therapeutic target against renal toxicity induced by cocaine.

Genetic overexpressing of GPx-1 attenuates cocaine-induced renal toxicity via induction of anti-apoptotic factors.

The present study investigates the role of the glutathione peroxidase (GPx)-1 gene in cocaine-induced renal damage in mice. Multiple doses of cocaine increased lipid peroxidation, protein oxidation, and glutathione oxidation in the kidney of the non-transgenic mice (non-TG mice). The enzymatic activities of GPx and glutathione reductase were significantly decreased in non-TG mice, whereas superoxide dismutase was increased in the early phase of cocaine exposure. Treatment with cocaine resulted in significant decreases in expression of Bcl-2 and Bcl-xl in the kidney of non-TG mice, which resulted in significant increases in Bax and cleaved-caspase 3. Consistently, cocaine-induced tubular epithelial vacuolization and focal tubular necrosis were mainly observed in the proximal tubules in the kidneys of non-TG mice. These renal pathologic changes were much less pronounced in GPx-1 TG than in non-TG mice. These results suggest that the GPx-1 gene is a protective factor against nephrotoxicity induced by cocaine via interactive modulations between antioxidant and cell survival signaling processes.

Repeated exposure to far infrared ray attenuates acute restraint stress in mice via inhibition of JAK2/STAT3 signaling pathway by induction of glutathione peroxidase-1.

Exposure to far-infrared ray (FIR) has been shown to exert beneficial effects on cardiovascular and emotional disorders. However, the precise underlying mechanism mediated by FIR remains undetermined. Since restraint stress induces cardiovascular and emotional disorders, the present study investigated whether exposure to FIR affects acute restraint stress (ARS) in mice. c-Fos-immunoreactivity (IR) was significantly increased in the paraventricular hypothalamic nucleus (PVN) and dorsomedial hypothalamic nucleus (DMH) in response to ARS. The increase in c-Fos-IR parallels that in oxidative burdens in the hypothalamus against ARS. Exposure to FIR significantly attenuated increases in the c-Fos-IR, oxidative burdens and corticosterone level. ARS elicited decreases in GSH/GSSG ratio, cytosolic Cu/Zn-superoxide dismutase (SOD-1), glutathione peroxidase (GPx), and glutathione reductase (GR) activities. FIR-mediated attenuation was particularly observed in ARS-induced decrease in GPx, but not in SOD-1 or GR activity. Consistently, ARS-induced decreases in GPx-1-immunoreactivity in PVN and DMH, and decreases in GPx-1 expression in the hypothalamus were significantly attenuated by FIR. ARS-induced significant increases in phosphorylation of JAK2/STAT3, and nuclear translocation and DNA-binding activity of NFκB were observed in the hypothalamus. Exposure to FIR selectively attenuated phosphorylation of JAK2/STAT3, but did not diminish nuclear translocation and DNA-binding activity of NFκB, suggesting that JAK2/STAT3 constitutes a critical target for FIR-mediated pharmacological potential. ARS-induced increase in c-Fos-IR in the PVN and DMH of non-transgenic mice was significantly attenuated by FIR exposure or JAK2/STAT3 inhibitor AG490. GPx-1 overexpressing transgenic mice significantly protected increases in the c-Fos-IR and corticosterone level induced by ARS. However, neither FIR exposure nor AG490 significantly affected attenuations by genetic overexpression of GPx-1. Moreover, AG490 did not exhibit any additional positive effects against the attenuation by genetic overexpression of GPx-1 or FIR exposure. Our results indicate that exposure to FIR significantly protects ARS-induced increases in c-Fos-IR and oxidative burdens via inhibition of JAK2/STAT3 signaling by induction of GPx-1.

Effects of vitamin D on blood pressure in patients with type 2 diabetes mellitus.

PURPOSE: Previous studies have suggested that vitamin D supplementation may decrease blood pressure in patients with type 2 diabetes, although conflicting results have been reported. The purpose of this meta-analysis was to evaluate the effects of the vitamin D supplementation on blood pressure in patients with type 2 diabetes. METHODS: A meta-analysis of published randomized controlled trials was conducted. Eligible studies were identified via a literature search of the MEDLINE (PubMed), EMBASE, and Cochrane Library databases through to May 25, 2015. The endpoint of the analysis was the change in blood pressure due to vitamin D treatment in patients with type 2 diabetes. These changes were calculated as the difference between the baseline and final measurements performed in each study. A fixed-effects model was used to calculate the combined effect estimates; in the presence of heterogeneity, a random-effects model was used. RESULTS: A total of 15 articles were included in the meta-analysis. All 15 articles, including 1,134 patients with type 2 diabetes, were analyzed for systolic blood pressure (SBP), and 13 articles, including 793 patients, were analyzed for diastolic blood pressure (DBP). The combined-effect estimate of vitamin D intervention on SBP was -0.121 mmHg (95% confidence interval (CI) -0.355 to 0.113, p = 0.311), and considerable heterogeneity was observed between studies (p < 0.001, I(2)= 74.2%). For DBP, the combined effect estimate was -0.160 mmHg (95% CI -0.298 to -0.022, p = 0.023), and no heterigenieity was observed (p = 0.673, I(2) = 0.0%). CONCLUSIONS: This study is the first meta-analysis of the effect of vitamin D supplementation on blood pressure in patients with type 2 diabetes. This meta-analysis demonstrated that vitamin D supplementation may result in a reduction in DBP in patients with type 2 diabetes. However, additional studies with large sample sizes and longer durations are needed to establish a relationship between vitamin D and blood pressure in patients with type 2 diabetes.

Beneficial Effects of Red Yeast Rice on High-Fat Diet-Induced Obesity, Hyperlipidemia, and Fatty Liver in Mice.

Obesity is a common cause of hyperlipidemia, which is a major coronary risk factor. Previous studies have shown red yeast rice (RYR) effectiveness in lowering low-density lipoprotein cholesterol. The aim of this study was to investigate the effects of RYR on obesity and hyperlipidemia. Mice were randomly separated into five groups: the control group with a normal diet, the high-fat diet (HFD) group fed a HFD without any treatment, and HFD-fed groups supplemented with RYR (1 g/kg/day for 8 weeks, 1 g/kg/day for 12 weeks, and 2.5 g/kg/day for 8 weeks). Body weight was recorded twice and food intake thrice weekly. Liver and fat pads were surgically removed and weighed. The levels of lipid parameters, liver enzymes, and leptin levels were measured. The HFD feeding resulted in obesity, which was associated with increases in body weight, liver weight, fat pad weight, liver enzymes, and plasma leptin levels with the development of hyperlipidemia. RYR prevented weight gain and fat pad weight in mice fed a HFD. RYR alleviated blood lipid parameters, liver enzymes, and leptin levels, and improved atherogenic index. These findings suggest that RYR has therapeutic potential in treating obesity and hyperlipidemia.

Clinical effect of a polysaccharide-rich extract of Acanthopanax senticosus on alcohol hangover.

The present study aimed to examine the effects polysaccharide-rich extract of Acanthopanax senticosus (PEA) on blood alcohol concentration (BAC) and hangover as well as blood lab parameters. A randomized, placebo-controlled, double-blind crossover trial was conducted. The PEA was orally administered before and after consuming alcohol 1.75 g/kg of pure alcohol. After alcohol consumption, BAC was measured for evaluation of alcohol pharmacokinetics. In the second day morning, subjects were asked to complete the Acute Hangover Scale (AHS) questionnarie. BAC results showed little difference between placebo and PEA groups, indicating that PEA does not have an effect on the pharmacokinetics of alcohol. However, several AHS items (i.e., tired, headache, dizziness, stomachache and nausea) and AHS total score were significantly improved by PEA. Blood lab parameters were significantly altered by alcohol in the placebo group. The alteration by alcohol of glucose and C-reactive protein (CRP) level was significantly attenuated by PEA. Therefore, PEA may have potential to reduce the severity of the alcohol hangover by inhibiting the alcohol-induced hypoglycemia and inflammatory response.