• Proceedings of the Korean Society of Applied Pharmacology
• /
• 2005.04a
• /
• pp.53-60
• /
• 2005

Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting $1\%$ of the population above the age of 65 and is characterized by a selective loss of dopaminergic neurons in the substantia nigra pars compacta. Although the underlying cause of dopaminergic cell death or the mechanism by which these cells degenerate is still not clearly understood, oxidative stress, mitochondrial dysfunction, and protein misfolding are thought to play important roles in the dopaminergic degeneration in PD. Tetrahydrobiopterin (BH4) is synthesized exclusively in the monoaminergic, including dopaminergic, cells and serves as an endogenous and obligatory cofactor for syntheses of the potential oxidative stressors dopamine and nitric oxide. In addition to its contribution toward the syntheses of these two potentially toxic molecules, BH4 itself can directly generate oxidative stress. BH4 undergoes oxidation during the hydroxylation reaction as well as nonenzymatic autooxidation to produce hydrogen peroxide and superoxide radical. We have previously suggested BH4 as an endogenous molecule responsible for the dopaminergic neurodegeneration. BH4 exerts selective toxicity to dopamine-producing cells via generation of oxidative stress, mitochondrial dysfunction, and apoptosis. BH4 also induces morphological, biochemical, and behavioral characteristics associated with PD in vivo. BH4 as well as enzyme activity and gene expression of GTP cyclohydrolase I, the rate-limiting enzyme in BH4 synthesis pathway, are readily upregulated by cellular changes such as calcium influx and by various stimuli including stress situations. This points to the possibility that cellular availability of BH4 might be increased in aberrant conditions, leading to increased extracellular BH4 subsequent degeneration. The fact that BH4 is specifically and endogenously synthesized in dopaminergic cells, Is readily upregulated, and generates oxidative stress-related cell death provides physical relevance of this molecule as an attractive candidate with which to explain the mechanism of pathogenesis of PD.

• Biomolecules & Therapeutics
• /
• v.23 no.5
• /
• pp.407-413
• /
• 2015

Paraquat dichloride (N,N-dimethyl-4-4'-bipiridinium, PQ) is an extremely toxic chemical that is widely used in herbicides. PQ generates reactive oxygen species (ROS) and causes multiple organ failure. In particular, PQ has been reported to be an immunotoxic agrochemical compound. PQ was shown to decrease the number of macrophages in rats and suppress monocyte phagocytic activity in mice. However, the effect of PQ on macrophage cell viability remains unclear. In this study, we evaluated the cytotoxic effect of PQ on the mouse macrophage cell line, RAW264.7 and its possible mechanism of action. RAW264.7 cells were treated with PQ (0, 75, and $150{\mu}M$), and cellular apoptosis, mitochondrial membrane potential (MMP), and intracellular ROS levels were determined. Morphological changes to the cell nucleus and cellular apoptosis were also evaluated by DAPI and Annexin V staining, respectively. In this study, PQ induced apoptotic cell death by dose-dependently decreasing MMP. Additionally, PQ increased the cleaved form of caspase-3, an apoptotic marker. In conclusion, PQ induces apoptosis in RAW264.7 cells through a ROS-mediated mitochondrial pathway. Thus, our study improves our knowledge of PQ-induced toxicity, and may give us a greater understanding of how PQ affects the immune system.

• Journal of Applied Biological Chemistry
• /
• v.62 no.4
• /
• pp.347-353
• /
• 2019

Stings of jellyfish, which frequently occur in a warm season, cause severe pain, inflammation and sometimes irreversible results such as the death. Harmful venoms from jellyfish, therefore, have been studied for finding the therapeutic agents to relieve pain or to neutralize toxic components. However, it is still unclear if and how jellyfish venom reveal neuronal toxicity even though pain induction seems to result from the activation of nociceptors such as nerve endings. In this study, using HT-22 cell line, we investigated neurotoxic effects of the venom of Chrysaora pacifica (CpV) which appears in South-East ocean of Korea. In 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, CpV significantly reduced the viability of HT-22 cells in a dose-dependent manner. Additionally, in 2',7'-Dichlorofluorescin diacetate fluorescence test under the culture condition lacking dominant inflammatory factors, CpV remarkably increased the production of intracellular reactive oxygen species (ROS). Reduced responsive fluorescence to Rhodamine123 and increased expression of intracellular cytochrome c were also observed in HT-22 cells treated with CpV. These indicate that CpV-reduced viability of HT-22 cells may be due to the activation of apoptotic signalings mediated with oxidative stress and mitochondrial dysfunction. Furthermore, removing Ca²⁺ ion or adding N-acetyl-Lcystein remarkably blocked the CpV effect to reduce the viability of HT-22 cells. The findings in this study clearly demonstrate that CpV may activate Ca²⁺-mediated ROS signalings and mitochondrial dysfunction resulting in neuronal damage or death, and suggest that blocking Ca²⁺ pathway is a therapeutic approach to possibly block toxic effects of jellyfish venoms.

• Korean Journal of Agricultural Science
• /
• v.47 no.3
• /
• pp.657-665
• /
• 2020

The objective of this study was to investigate whether supplementation of pentoxifylline (PTX; phosphodiesterase inhibitor) to thawed boar semen improves the post-thaw motility of sperm and affects the efficiency of artificial insemination (AI) and further development. To determine the concentration of PTX for AI, frozen-thawed semen was incubated with 0, 5, 10, and 20 mM PTX in an extender freezing medium, respectively, after thawing. Kinematic properties of sperm were examined with a computer-assisted semen analysis (CASA) system. In addition, viability and mitochondrial activity were also tested by LIVE/DEAD and a MitoTracker kit. There were no significant differences in the kinetic parameters of thawed sperm between control and treatment groups, but overall assessment parameters such as motility and rapid progressive were higher in the 10 mM PTX group. In the viability and mitochondrial assay, there were no significant differences observed in the PTX treatment, compared to the control. For further analysis, artificial inseminations were performed using frozen semen and 10 mM PTX treated cryopreserved semen, respectively. There were no differences in pregnancy rates and fetus weights among the groups until 30 and 40 days, but litter size was reduced and relatively low-birth weight was observed in the PTX group. In summary, our findings suggest that enhancement of in vitro sperm quality or non-toxicity supplemented by PTX may have detrimental effects on fetus development.

• The Korea Journal of Herbology
• /
• v.28 no.2
• /
• pp.33-38
• /
• 2013

Objects : Apoptosis leads to the death of a cell. The mitochondrial pathway of apoptosis, a process regulated by the Bcl-2 family of proteins, plays a key role in various biological processes. The tuber of Liriope platyphylla Wang et TANG (Liliaceae), also known as Liriopis tuber, is famous in Oriental medicine owing to its tonic, antitussive, expectorant and anti-asthmatic properties. The purpose of this study was to observe the effect of the Liriopis tuber on mitochondrial-mediated apoptosis in PC-12 cells. Method : A cytotoxic test on Liriopis Tuber water extract was conducted and another MTT assay was conducted to observe the cytoprotective effect against 4-HNE 25 ${\mu}M$ that causes oxidative stress in PC-12 cells for 24 hours. In addition, in order to observe the expression of Bcl-2 and Bax protein involved with apoptosis, western blot was conducted. Results : The LT water extract had no toxicity for PC-12 cell. In the cytoprotective effect against 4-HNE, both of the group treated with 50 ${\mu}g/m{\ell}$ and 100 ${\mu}g/m{\ell}$ of LT water extract showed a significant increase in comparison with the control group. In Bax protein expression, all the experimental groups treated with LT water extract showed a decrease in comparison with the control group but had no significance. In Bcl-2 protein expression, all the experimental groups treated with LT water extract showed a significant increase in comparison with the control group. Conclusion : These results suggest that LT is effective in reducing apoptosis.

• Korean Journal of Pharmacognosy
• /
• v.35 no.2 s.137
• /
• pp.175-178
• /
• 2004

The cricket has been used in East Asia as crude drugs for treating fever and hypertension, and is presently reared as a pharmaceutical insect in China and a food for animals. For the purpose of evaluating protective extracts against alcohol-induced toxicity, the extracts of the cricket (Gryllus bimaculatus) were examined in animal models acutely administered alcohol by the cricket in ICR-mice. Water and methanol extracts from the cricket, were found to cause a significant decrease (37%) in the blood ethanol concentration as well as enhancement of liver mitochondrial alcohol dehydogenase (ADH) and acetaldehyde dehydogenase (ALDH) activitieson on a single intraperitoneal administration in mice. Futhermore methanol extract was demonstrated to exhibit more potent enhancing activity on ethanol metabolism than water extract. These results suggest that water/alcohol extract of G. bimaculatus may be used as a food for reducing the toxicity of alcohol.

• The Korean Journal of Pharmacology
• /
• v.31 no.2
• /
• pp.165-177
• /
• 1995

Dissociated cell cultures from rat embryonic ventral mesencephalon were used to evaluate the mechanisms of $MPP^+$ neurotoxicity. The cells were treated with MPTP or $MPP^+$ and the viability of the cells was assessed biochemically; tyrosine hydroxylase (TH) immunoreactivity, protein, intracellular ATP and lactate content and lipid peroxidation. Also the generation of the intracellular oxidants was measured after loading 2', 7‘-dichlorofluorescin diacetate to the cells. When cultures were exposed to 0.1 mM $MPP^+$, at 2 hour incubation lactate was significantly accumulated in the cells and then the intracellular ATP content and TH immunoreactivity were decreased dose- and time-dependently. But, malondialdehyde as an index for lipid peroxidation was not changed even though the generation of the intracellular oxidants was stimulated by the addition of $MPP^+$. On the other hand, 1 mM MPTP significantly reduced the TH immunoreactivity at 24 hour exposure without any change in the intracellular A TP, lactate and MDA content until 6 hour exposure. And also MPTP inhibited the generation of the intracellular oxidants from control cells and $MPP^+$ exposed cells. These results indicate that cytotoxicity of $MPP^+$ is mediated by inhibiting the mitochondrial energy metabolism rather than generating the intracellular oxidants. And MPTP would have direct action in addition to conveting to the toxic metabolite, $MPP^+$ to exert the toxicity on the dopaminergic neurons.

• Korean Journal of Acupuncture
• /
• v.37 no.2
• /
• pp.97-103
• /
• 2020

Objectives : Parkinson's disease, a progressive neurodegenerative disease, is caused by the loss of dopaminergic neurons in the substantia nigra. There is no clear treatment or remedy for Parkinson's disease; therefore, the development of novel therapies related to anti-inflammatory and antioxidant effects is required. This study was performed to evaluate the neuroprotective effect of water extracts from Cervi Cornu (CC) in dopaminergic cells. Methods : We studied effects of CC on apoptosis, cell death and inflammation in SH-SY5Y neuroblastoma cells treated by methylpyridinium ion (MPP+). SH-SY5Y cell line was treated with CC for 24 hours and then 500 μM MPP+ for 18 hours. Results : Cervi Cornu treatment inhibited the decrease in tyrosine hydroxylase (TH) expression and decreased the activation of inflammatory factors mitochondrial cytochrome C oxidase (COX2) and inducible NO synthase (iNOS) against MPP+ neurotoxicity. Apoptosis factors BCL2 associated X, apoptosis regulator (BAX) levels were decreased and B-Cell CLL/Lymphoma 2 (BCL2) levels were increased. Conclusions : These results suggest that CC treatment had neuroprotective effects in the SH-SY5Y neuroblastoma cells against toxicity induced by MPP+. The results suggest new possibilities of CC for the treatment of Parkinson's disease.

• Applied Microscopy
• /
• v.18 no.2
• /
• pp.187-204
• /
• 1988

The present experiment was performed to investigate the acute and subacute effect of lead acetate on ultrastructural and biochemical changes in mouse diencephalon. In acute case, mouse were peritoneally injected with lead acetate at a dose of 0.26 mmole/kg body weight, and after treatment, mouse were sacrificed at time intervals of 12, 24, 48, and 96 hours. In subacute case, mouse were injected at doses of 0.07 mmoie/kg B. W. and 0.13 mmole/kg B.W. once at two days, and after treatment, mouse wee sacrificed at 1 week, 2 weeks, and 3 weeks. It was observed that after acute treatment, changes composed of increased monoamine oxidase activity, $Na^{+}-K^{+}$ ATPase activity, decreased $Mg^{2+}$-APTase activity, wrinkled myelin, swollen Golgi apparatus and more dense synaptic vesicle in nerve terminal. After subacute treatment, decreased monoamine oxidase activity, increased $Mg^{2+}$-ATPase, $Na^{+}-K^{+}$ ATPase, lose of myelin, uneven mitochondrial distribution, synaptic vesicular density and edema, but at a higher dose the effect was more severe. Therefore, lead acetate caused abnormal change of diencephalon, and at a subacute, it appears metal accumulative toxicity.

• Applied Microscopy
• /
• v.24 no.1
• /
• pp.77-85
• /
• 1994

In order to investigating the pulmonary toxicity of the O-chlorobenzyledene malononitrile (CS), lacrimating agent, $2.6g/m^3$ of CS was inhalated to Sprague-Dawley rats in the plastic chamber for 20 minutes. The ultrastructural changes of type II pneumocytes in the lung were observed with Hitachi 600 transmission electron microscope. The results obtained were as follows: 1. 3 hours after exposure to CS the fusion of surface microvilli, dilatation of cristernae of the rough endoplasmic reticulum, atrophy of Golgi complex and condensation, deletion of lamellated membranes in lamellar bodies were observed in type II pneumocytes. 2. One and 2 days after CS-exposure, disorganization of mitochondrial double membranes, fragmentations of rough endoplasmic reticulum were found in the great alveolar cells. In addition, decrease in amount of polyribosome granules and deletion or condensation of lamellated membranes in lamellar bodies were also observed. 3. 4 days after exposure to CS, the type II pneumocyte revealed new whorled lamellar membranes in lamellar bodies, a few intact rough endoplasmic reticulum and restoration of polyribosome granules. It is consequently suggested that CS induces degenerative changes of cytoplasmic organelles in the type II pneumocytes.