• Archives of Pharmacal Research
• /
• v.28 no.8
• /
• pp.942-947
• /
• 2005

Peroxynitrite is a potent neurotoxic molecule produced from a reaction between NO and super-oxide and induces NO-mediated inflammation under neuropathological conditions. Previously, we reported that glucose deprivation induced ATP depletion and cell death in immunostimulated astrocytes, which was mainly due to peroxynitrite. In this study, the role of MAPKs (ERK1/2, p38MAPK, and JNK/SAPK) signal pathway in the SIN-1/glucose deprivation-induced death of astrocytes was examined. A combined treatment with glucose deprivation and $50 {\mu}M$ SIN-1, an endogenous peroxynitrite generator, rapidly and markedly increased the death in rat primary astrocytes. Also, SIN-1/glucose deprivation resulted in the activation of MAPKs, which was significantly blocked by the treatment with $20{\mu}M$ MAPKs inhibitors (ERK1/2, PD98059; p38MAPK, SB203580; JNK/SAPK, SP600125). Interestingly, SIN-1/glucose deprivation caused the loss of intracellular ATP level, which was significantly reversed by MAPKs inhibitors. These results suggest that the activation of MAPKs plays an important role in SIN-1/glucose deprivation-induced cell death by regulating the intracellular ATP level.

• Journal of Pharmacopuncture
• /
• v.14 no.3
• /
• pp.19-45
• /
• 2011

Objectives: This study was performed to analyse the effects of Sweet Bee Venom(Sweet BV-pure melittin, the major component of honey bee venom) on the central nervous system in rats. Methods: All experiments were conducted at Biotoxtech Company, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Male rats of 5 weeks old were chosen for this study and after confirming condition of rats was stable, Sweet BV was administered in thigh muscle of rats. And checked the effects of Sweet BV on the central nervous system using the functional observational battery (FOB), which is a neuro-toxicity screening assay composed of 30 descriptive, scalar, binary, and continuous endpoints. And home cage observations, home cage removal and handling, open field activity, sensorimotor reflex test/physiological measurements were conducted. Results: 1. In the home cage observation, there was not observed any abnormal signs in rats. 2. In the observation of open field activity, the reduction of number of unit areas crossed and rearing count was observed caused by Sweet BV treatment. 3. In the observation of handling reactivity, there was not observed any abnormal signs in rats. 4. In the observation of sensorimotor reflex tests/physiological measurements, there was not observed any neurotoxic signs in rats. 5. In the measurement of rectal temperature, treatment of Sweet BV did not showed great influences in the body temperature of rats. Conclusions: Above findings suggest that Sweet BV is relatively safe treatment in the central nervous system. But in the using of over dose, Sweet BV may the cause of local pain and disturbance of movement. Further studies on the subject should be conducted to yield more concrete evidences.

• Toxicological Research
• /
• v.12 no.1
• /
• pp.69-79
• /
• 1996

Primary culture of cerebellar neuronal cells derived from 8-day old Long-Evans rats was used. Pure granule cells, astrocytes or mixed cells culture systems were prepared. These cells were differentiated and developed synaptic connections. And the astrocytes were identified by immunostaining with glial fibrillary acidic protein (GFAP). Methamphetamine (MAP), which acts on dopaminergic system and cadmium (Cd), a toxic heavy metal, were applied and biochemical assays and electrophysiological studies were performed. $LC_50$ values estimated by MTT assay of MAP and Cd were 3 mM and 2$\mu M$ respectively. Cells were treated with 1 mM or 2 mM MAP and 1$\mu M$ $CdCl_2$ for 48 hour, and the incubation media were analyzed for the content of released LDH. MAP (2 mM) and Cd significantly increased the LDH release. Cell viability was decreased in both groups and some cytopathological changes like cell swelling or vacuolization were seen. The cerebellar granule cells were used for measuring membrane currents using whole-cell clamp technique. Sodium and potassium currents were not affected by MAP neither Cd, but calcium current was significantly reduced by Cd but not affected by MAP. Therefore, in vitro neurotoxicity test system using neuronaI cells and astrocytes cultures were established and can be used in screening of potential neurotoxic chemicals.

• Biomolecules & Therapeutics
• /
• v.11 no.4
• /
• pp.214-223
• /
• 2003

Methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA) have become popular recreational drugs of abuse in many countries. Although the neurotoxic damage caused by METH and MDMA is characterized by degeneration of the dopaminergic and serotonergic systems in brain, the molecular and cellular mechanisms remain to be clarified. Therefore, the purposes of this study were to confirm the capability of METH and MDMA to induce apoptosis and to clarify the action of its molecular mechanism by using serotonergic JAR cells and dopaminergic SK-N-SH cells. METH and MDMA were dose-dependently cytotoxic to human serotonergic JAR cells and dopaminergic SK-N-SH cells. The morphological change of apoptosis was found in Giemsa staining and TUNEL and further verified in DNA fragmentation analysis. Immunoblotting analysis revealed proteolytic cleavage of caspase-3 and -9 and change of bcl-2 and bax proteins. These results suggest that METH and MDMA may induce caspase-dependent apoptosis via the mitochondrial cell death pathway and METH and MDMA-induced neurotoxicity may happen to broadly and independently of both dopaminergic and serotonergic systems.

• Journal of Preventive Medicine and Public Health
• /
• v.30 no.3 s.58
• /
• pp.577-584
• /
• 1997

Validation and Standardization of neurobehavioral instrument in Korean occupational setting has not been studied ever. This study tried to validate the newly developed computerized psychomotor tests, Neurobehavioral Tests for Occupational Screening (NTOS). Male patients with Parkinson's disease(n=12) and male workers who never exposed to occupational neurotoxic materials and didn't have neurologic disease(n=21), performed some tests from NTOS; simple reaction time, choice reaction time(2 choice), and finger tapping(both hands). In simple analysis, difference between patient group and worker group was significantly great. Adjusted for age and education years, simple reaction time and finger tapping(both hand) were statistically significantly different between two groups(p<.05). Choice reaction time was also different(p<.1) but error frequency of choice reaction time test was not. Generally, this results showed NTOS could detect impairment of psychomotor function. But insensitive results of choice reaction time was partly due to small sample size and confounding variables and so required future study and refinement at improvement of NTOS.

• Journal of Preventive Medicine and Public Health
• /
• v.26 no.2 s.42
• /
• pp.282-292
• /
• 1993

Neurotoxicity in the workplace may occur with exposure to scores of chemicals. Although large acute outbreaks of the occupational neurological disease are rare, the incidence of occupational neurotoxicity in its subtler aspects is unknown. A working knowledge of both the major occupational neurotoxic solvents and the tools used by cliniical neurologists and neurotoxicologists to evaluate neurotoxicity in working populations is a necessity fur the occupational physician. To investigate the effects of carbon disulfide($CS_2$) on the peripheral nerve system using the nervous conduction study, 105 male workers working in the spinning room of a viscose rayon factory were examined and compared with a sex and age matched, unexposed 105 male controls using t-test analysis. 72.4% of $CS_2$-exposed workers complained of neurological symptoms, and the abnormal cases in nerve conduction study were 48.6%. The abnormal cases of nerve conduction study increased in number according as the age and duration of exposure increased. In this study, asymptomatic workers were confirmed to have subclinical neuropathy by nerve conduction study. Also as there were abnormal cases even in its duration of exposure below 4 years, nerve conduction study turned out to be ways of discovering of early peripheral neuropathy. In nerve conduction study, the amplitude, velocity, F-wave latency and H-reflex of the motor and sensory nerves in both upper and lower extremities were significant different between $CS_2$-exposed workers and the controls. From the pathological viewpoint, both segmental and axonal degenerations were assumed in this study.

• Toxicological Research
• /
• v.35 no.1
• /
• pp.83-91
• /
• 2019

Nanoparticles (NPs) have been recognized as both useful tools and potentially toxic materials in various industrial and medicinal fields. Previously, we found that zinc oxide (ZnO) NPs that are neurotoxic to human dopaminergic neuroblastoma SH-SY5Y cells are mediated by lipoxygenase (LOX), not cyclooxygenase-2 (COX-2). Here, we examined whether human bone marrow-derived mesenchymal stem cells (MSCs), which are different from neuroblastoma cells, might exhibit COX-2- and/or LOX-dependent cytotoxicity of ZnO NPs. Additionally, changes in annexin V expression, caspase-3/7 activity, and mitochondrial membrane potential (MMP) induced by ZnO NPs and ZnO were compared at 12 hr and 24 hr after exposure using flow cytometry. Cytotoxicity was measured based on lactate dehydrogenase activity and confirmed by trypan blue staining. Rescue studies were executed using zinc or iron chelators. ZnO NPs and ZnO showed similar dose-dependent and significant cytotoxic effects at concentrations ${\geq}15{\mu}g/mL$, in accordance with annexin V expression, caspase-3/7 activity, and MMP results. Human MSCs exhibited both COX-2 and LOX-mediated cytotoxicity after exposure to ZnO NPs, which was different from human neuroblastoma cells. Zinc and iron chelators significantly attenuated ZnO NPs-induced toxicity. Conclusively, these results suggest that ZnO NPs exhibit both COX-2- and LOX-mediated apoptosis by the participation of mitochondrial dysfunction in human MSC cultures.

• The Korean Journal of Food And Nutrition
• /
• v.31 no.6
• /
• pp.865-872
• /
• 2018

In neuronal cell deaths, oxidative stress is normally implicated with a most of these deaths occurring in neurodegenerative disorders such as the Alzheimer's and Parkinson's diseases. In this study, the neuroprotective effects of Schisandra chinensis (SC) and Ribes fasciculatum (RF) extracts on hydrogen peroxide ($H_2O_2$)-induced oxidative stress in neuroblastic cell line were investigated. For an hour, hydrogen peroxide of $100{\mu}M$ concentration, was induced on neuroblastic cells, causing apoptic cell death. For the neuroprotection, a sample of neuroblastic cells had been pre-treated with SC and RF extracts for 24 hours before application of the hydrogen peroxide. No neurotoxic effects were observed in the cells that had been treated by SC and RF. This prove that the treatment of SC and RF extract prevented apoptotic cell death of neuroblastic cell line exposed to oxidative injury. In addition, applying both SC and RF extracts at a 7:3 ratio increased the neuronal cell survival rate, compared to individual treatments of SC and RF extract. This study suggests that SC and RF extracts may be potential therapeutic agents for the prevention of neuronal cell death.

• Biomolecules & Therapeutics
• /
• v.27 no.2
• /
• pp.168-177
• /
• 2019

Dysregulation of excitatory neurotransmission has been implicated in the pathogenesis of neuropsychiatric disorders. Pharmacological inhibition of N-methyl-D-aspartate (NMDA) receptors is widely used to model neurobehavioral pathologies and underlying mechanisms. There is ample evidence that overstimulation of NMDA-dependent neurotransmission may induce neurobehavioral abnormalities, such as repetitive behaviors and hypersensitization to nociception and cognitive disruption, pharmacological modeling using NMDA has been limited due to the induction of neurotoxicity and blood brain barrier breakdown, especially in young animals. In this study, we examined the effects of intraperitoneal NMDA-administration on nociceptive and repetitive behaviors in ICR mice. Intraperitoneal injection of NMDA induced repetitive grooming and tail biting/licking behaviors in a dose- and age-dependent manner. Nociceptive and repetitive behaviors were more prominent in juvenile mice than adult mice. We did not observe extensive blood brain barrier breakdown or neuronal cell death after peritoneal injection of NMDA, indicating limited neurotoxic effects despite a significant increase in NMDA concentration in the cerebrospinal fluid. These findings suggest that the observed behavioral changes were not mediated by general NMDA toxicity. In the hot plate test, we found that the latency of paw licking and jumping decreased in the NMDA-exposed mice especially in the 75 mg/kg group, suggesting increased nociceptive sensitivity in NMDA-treated animals. Repetitive behaviors and increased pain sensitivity are often comorbid in psychiatric disorders (e.g., autism spectrum disorder). Therefore, the behavioral characteristics of intraperitoneal NMDA-administered mice described herein may be valuable for studying the mechanisms underlying relevant disorders and screening candidate therapeutic molecules.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.1
• /
• pp.144-153
• /
• 2021

Organophosphorus nerve agents (OPNAs), including both G- and V-type nerve agents such as sarin, soman, tabun and VX, are extremely neurotoxic organophosphorus compounds. Catalytic bioscavengers capable of hydrolyzing OPNAs are under development because of the low protective effects and adverse side effects of chemical antidotes to OPNA poisoning. However, these bioscavengers have certain limitations for practical application, including low catalytic activity and narrow specificity. In this study, we generated a fusion-hybrid form of engineered recombinant human paraoxonase 1 (rePON1) and bacterial organophosphorus hydrolase (OPH), referred to as GV-hybrids, using a flexible linker to develop more promising catalytic bioscavengers against a broad range of OPNAs. These GV-hybrids were able to synergistically hydrolyze both G-type OPNA analogs (paraoxon: 1.7 ~ 193.7-fold, p-nitrophenyl diphenyl phosphate (PNPDPP): 2.3 ~ 33.0-fold and diisopropyl fluorophosphates (DFP): 1.4 ~ 22.8-fold) and V-type OPNA analogs (demeton-S-methyl (DSM): 1.9 ~ 34.6-fold and malathion: 1.1 ~ 4.2-fold above) better than their individual enzyme forms. Among the GV-hybrid clones, the GV7 clone showed remarkable improvements in the catalytic activity toward both G-type OPNA analogs (kcat/Km (106 M-1 min-1): 59.8 ± 0.06 (paraoxon), 5.2 ± 0.02 (PNPDPP) and 47.0 ± 6.0 (DFP)) and V-type OPNA analogs (kcat/Km (M-1 min-1): 504.3 ± 48.5 (DSM) and 1324.0 ± 47.5 (malathion)). In conclusion, we developed GV-hybrid forms of rePON1 and bacterial OPH mutants as effective and suitable catalytic bioscavengers to hydrolyze a broad range of OPNA analogs.