- Understanding the role of glycogen synthase kinase-3 in L-DOPA-induced dyskinesia in Parkinson's disease. [Review]
- EOExpert Opin Drug Metab Toxicol 2018; 14(1):83-90
- Levodopa (L-DOPA) is the most commonly used drug for Parkinson's disease (PD), but its long-term use is associated with various complications, including L-DOPA-induced dyskinesia (LID). Many studies ...
Levodopa (L-DOPA) is the most commonly used drug for Parkinson's disease (PD), but its long-term use is associated with various complications, including L-DOPA-induced dyskinesia (LID). Many studies have suggested that L-DOPA neurotoxicity and LID are associated with glycogen synthase kinase-3 (GSK-3) activation. Areas covered: LID is caused by striatal dopamine (DA) denervation in PD and pulsatile L-DOPA treatment. These factors lead to dysregulated DA transmission, abnormal intracellular signaling and transcription factors in striatal neurons, and altered gene expression and plasticity at corticostriatal synapses. The mechanisms of L-DOPA toxicity involve oxidative stress, L-DOPA oxidation to quinone, mitochondrial dysfunction, and α-synuclein. GSK-3 has been suggested to play key roles in all the mechanisms associated of L-DOPA toxicity and LID in PD. Expert opinion: GSK-3 plays critical roles in L-DOPA-induced neurotoxicity, and the development of specific methods to inhibit GSK-3 function may help prevent L-DOPA neurotoxicity and LID in PD. However, balanced GSK-3 inhibition and less β-catenin degradation is essential for preventing LID, because too much GSK-3 inhibition increases β-catenin levels, which is related to cancers.
- Gerbil bite anaphylaxis. [Case Reports]
- AJAm J Emerg Med 2018; 36(1):171.e5-171.e6
- Household pets are well known to cause allergic symptoms in susceptible individuals, most commonly conjunctivitis, rhinitis, bronchospasm or urticaria. The increasing prevalence of exotic pets, inclu...
Household pets are well known to cause allergic symptoms in susceptible individuals, most commonly conjunctivitis, rhinitis, bronchospasm or urticaria. The increasing prevalence of exotic pets, including rodents, may introduce novel allergens into the household setting. We describe the case of a 16-year-old female who presented to the emergency department (ED) with an immediate systemic reaction consistent with anaphylaxis following a bite injury from a pet Mongolian gerbil. Although rare, gerbil bite injury represents another possible allergen source for precipitating a severe allergic reaction.
- Effect of the 5α-reductase enzyme inhibitor dutasteride in the brain of intact and parkinsonian mice. [Journal Article]
- JSJ Steroid Biochem Mol Biol 2017; 174:242-256
- Dutasteride is a 5alpha-reductase inhibitor in clinical use to treat endocrine conditions. The present study investigated the neuroprotective mechanisms of action of dutasteride in intact and 1-methy...
Dutasteride is a 5alpha-reductase inhibitor in clinical use to treat endocrine conditions. The present study investigated the neuroprotective mechanisms of action of dutasteride in intact and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mice using a low dose of MPTP not affecting motor activity modeling early stages of Parkinson's disease (PD). We hypothesized that dutasteride neuroprotection is due to altered steroids levels. Dutasteride pre-treatment prevented loss of striatal dopamine (DA) and its metabolite DOPAC. Dutasteride decreased effects of MPTP on striatal dopamine transporter (DAT), vesicular monoamine transporter 2 (VMAT2) and D2 DA receptor specific binding while D1 receptor specific binding remained unchanged. Dutasteride enhanced DAT specific binding and the glycosylated form of DAT in intact mice. MPTP-lesioned mice had plasma and brain testosterone and dihydrotestosterone levels lower than control mice whereas progesterone and its metabolites (dihydroprogesterone, isopregnanolone and tetrahydroprogesterone) pathway showed increases. Dutasteride treatment by inhibiting transformation of progesterone and testosterone to its metabolites elevated plasma and brain concentrations of testosterone compared to MPTP mice and decreased DHT levels in intact mice. Plasma and brain estradiol levels were low and remained unchanged by MPTP and/or dutasteride treatment. Dutasteride treatment did not affect striatal phosphorylation of Akt and its downstream substrate GSK3β as well as phosphorylation of ERK1/2 in intact and MPTP lesioned MPTP mice. Striatal glial fibrillary acidic protein (GFAP) levels were markedly elevated in MPTP compared to control mice and dutasteride reduced GFAP levels in MPTP mice. Treatment with dutasteride post-lesion left unchanged striatal DA levels. These results suggest dutasteride as promising drug for PD neuroprotection.
- Correlation of abdominopelvic computed tomography with clinical manifestations in methamphetamine body stuffers. [Journal Article]
- RMRadiol Med 2018; 123(2):98-104
- Little is known about methamphetamine body stuffers and correlation of clinical manifestations with imaging studies. Current study was done to determine abdominopelvic computed tomography findings an...
Little is known about methamphetamine body stuffers and correlation of clinical manifestations with imaging studies. Current study was done to determine abdominopelvic computed tomography findings and clinical manifestations in methamphetamine body stuffers. In an IRB-approved routine data base study, demographic characteristics, clinical findings, and CT results of 70 methamphetamine body stuffers were retrieved. According to the clinical manifestations, the patients were categorized into either benign- or severe-outcome group. Also, they were determined to have positive or negative CT results. In the group with positive results, number and place of the baggies were determined, as well. Results of the CT were compared between the two groups. Almost 43% of the patients had positive abdominopelvic CT results. Mean density of the packs was 176.2 ± 152.7 Hounsfield unit. Based on the clinical grounds, 57% of the patients were in the benign- and 33% were in the severe-outcome group. In the benign group, 45% of the patients had positive CTs while in the severe-risk group, this was 40% (p > 0.05). Except variables defined as severe outcome (seizure, intubation, creatinine level, aspartate aminotransferase level, creatine phosphokinase and troponin level), agitation, on-arrival pulse rate, lactate dehydrogenase, bicarbonate, base excess, loss of consciousness and hospitalization period were correlating factors. But in regression analysis, we could not find a significant variable that prognosticate severe outcome. It seems that there is no relationship between the CT findings and clinical manifestations of the methamphetamine body stuffers. Severe outcomes may be observed even in the face of negative CTs.
- A Novel Bibenzyl Compound (20C) Protects Mice from 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine/Probenecid Toxicity by Regulating the α-Synuclein-Related Inflammatory Response. [Journal Article]
- JPJ Pharmacol Exp Ther 2017; 363(2):284-292
- The novel bibenzyl compound 2-[4-hydroxy-3-(4- hydroxyphenyl) benzyl]-4-(4- hydroxyphenyl) phenol (20C) plays a neuroprotective role in vitro, but its effects in vivo have not yet been elucidated. In...
The novel bibenzyl compound 2-[4-hydroxy-3-(4- hydroxyphenyl) benzyl]-4-(4- hydroxyphenyl) phenol (20C) plays a neuroprotective role in vitro, but its effects in vivo have not yet been elucidated. In this study, we estimated the efficacy of 20C in vivo using a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/probenecid (MPTP/p) mouse model from behavior, dopamine, and neuron and then the possible mechanisms for these effects were further investigated. The experimental results showed that 20C improved behavioral deficits, attenuated dopamine depletion, reduced dopaminergic neuron loss, protected the blood-brain barrier (BBB) structure, ameliorated α-synuclein dysfunction, suppressed glial activation, and regulated both nuclear factor-κB (NF-κB) signaling and the NOD-like receptor protein (NLRP) 3 inflammasome pathway. Our results indicated that 20C may prevent neurodegeneration in the MPTP/p mouse model by targeting α-synuclein and regulating α-synuclein-related inflammatory responses, including BBB damage, glial activation, NF-κB signaling, and the NLRP3 inflammasome pathway.
- RNA sequencing analysis reveals new findings of hyperbaric oxygen treatment on rats with acute carbon monoxide poisoning. [Journal Article]
- UHUndersea Hyperb Med 2016 Nov-Dec; 43(7):759-770
- CONCLUSIONS: This study is the first RNA-seq analysis profile of HBO₂ treatment on rats with acute CO poisoning. It concludes that changes of hormone secretion in the hypothalamic-pituitary system, dopamine metabolism and NO synthesis involved in brain damage and behavior abnormalities after CO poisoning and HBO₂ therapy may regulate these changes.
- Ephedrine-induced mitophagy via oxidative stress in human hepatic stellate cells. [Journal Article]
- JTJ Toxicol Sci 2017; 42(4):461-473
- The herb Ephedra sinica (also known as Chinese ephedra or Ma Huang), used in traditional Chinese medicine, contains alkaloids identical to ephedrine and pseudoephedrine as its principal active consti...
The herb Ephedra sinica (also known as Chinese ephedra or Ma Huang), used in traditional Chinese medicine, contains alkaloids identical to ephedrine and pseudoephedrine as its principal active constituents. Recent studies have reported that ephedrine has various side effects in the cardiovascular and nervous systems. In addition, herbal Ephedra, a plant containing many pharmacologically active alkaloids, principally ephedrine, has been reported to cause acute hepatitis. Many studies reported clinical cases, however, the cellular mechanism of liver toxicity by ephedrine remains unknown. In this study, we investigated hepatotoxicity and key regulation of mitophagy in ephedrine-treated LX-2 cells. Ephedrine triggered mitochondrial oxidative stress and depolarization. Mitochondrial swelling and autolysosome were observed in ephedrine-treated cells. Ephedrine also inhibited mitochondrial biogenesis, and the mitochondrial copy number was decreased. Parkin siRNA recovered the ephedrine-induced mitochondrial damage. Excessive mitophagy lead to cell death through imbalance of autophagic flux. Moreover, antioxidants and reducing Parkin level could serve as therapeutic targets for ephedrine-induced hepatotoxicity.
- Baicalein Protects against Rotenone-Induced Neurotoxicity through Induction of Autophagy. [Journal Article]
- BPBiol Pharm Bull 2017 Sep 01; 40(9):1537-1543
- Baicalein, a typical flavonoid compound, has neuroprotective properties in several neurological disorders. Autophagy plays a central role in maintaining the cellular homeostasis, and is involved in t...
Baicalein, a typical flavonoid compound, has neuroprotective properties in several neurological disorders. Autophagy plays a central role in maintaining the cellular homeostasis, and is involved in the pathogenesis of Parkinson's disease (PD). Recently, baicalein has been reported to induce autophagy. Therefore, the current study was designed to investigate whether baicalein could protect against rotenone-induced neurotoxicity via induction of autophagy both in SH-SY5Y cells and in a mouse model. A chronic PD mouse model was established by continuous intragastric administration of rotenone for 12 weeks. Baicalein was administrated from 7 to 12 week. Our results showed that baicalein prevented rotenone-induced behavioral deficits, dopaminergic neuronal loss, apoptosis and mitochondrial dysfunction. Furthermore, baicalein restored rotenone-impaired autophagy, and blocking the baicalein-induced autophagy using 3-methyladenine inhibited the neuroprotective effects of bacalein. Baicalein increased cell viability and restored mitochondrial function in SH-SY5Y cells. The beneficial effect of baicalein was abrogated by 3-methyladenine treatment. Furthermore, rapamycin increased autopahgy and reduced the rotenone-induced neurotoxicity in SH-SY5Y cells. Collectively, these results suggest that baicalein could prevent rotenone-induced neurotoxicity via restoring autophagy.
- Mechanisms of hepatocellular toxicity associated with new psychoactive synthetic cathinones. [Journal Article]
- TToxicology 2017 07 15; 387:57-66
- Synthetic cathinones are a new class of psychostimulant substances. Rarely, they can cause liver injury but associated mechanisms are not completely elucidated. In order to increase our knowledge abo...
Synthetic cathinones are a new class of psychostimulant substances. Rarely, they can cause liver injury but associated mechanisms are not completely elucidated. In order to increase our knowledge about mechanisms of hepatotoxicity, we investigated the effect of five frequently used cathinones on two human cell lines. Bupropion was included as structurally related drug used therapeutically. In HepG2 cells, bupropion, MDPV, mephedrone and naphyrone depleted the cellular ATP content at lower concentrations (0.2-1mM) than cytotoxicity occurred (0.5-2mM), suggesting mitochondrial toxicity. In comparison, methedrone and methylone depleted the cellular ATP pool and induced cytotoxicity at similar concentrations (≥2mM). In HepaRG cells, cytotoxicity and ATP depletion could also be demonstrated, but cytochrome P450 induction did not increase the toxicity of the compounds investigated. The mitochondrial membrane potential was decreased in HepG2 cells by bupropion, MDPV and naphyrone, confirming mitochondrial toxicity. Bupropion, but not the other compounds, uncoupled oxidative phosphorylation. Bupropion, MDPV, mephedrone and naphyrone inhibited complex I and II of the electron transport chain, naphyrone also complex III. All four mitochondrial toxicants were associated with increased mitochondrial ROS and increased lactate production, which was accompanied by a decrease in the cellular total GSH pool for naphyrone and MDPV. In conclusion, bupropion, MDPV, mephedrone and naphyrone are mitochondrial toxicants impairing the function of the electron transport chain and depleting cellular ATP stores. Since liver injury is rare in users of these drugs, affected persons must have susceptibility factors rendering them more sensitive for these drugs.
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- A little "dab" will do ya' in: a case report of neuro-and cardiotoxicity following use of cannabis concentrates. [Case Reports]
- CTClin Toxicol (Phila) 2017; 55(9):1011-1013
- CONCLUSIONS: Tetrahydrocannabinol (THC) has been increasingly associated with agitation and cardiotoxicity, while cannabidiol (CBD) has been associated with neuroprotective, inhibitory states. We propose that increasing concentrations of THC as well as THC:CBD ratios seen in cannabis concentrates such as "dabs" may cause agitation and end-organ damage through sympathomimetic and serotonergic pathways.