• The Journal of Internal Korean Medicine
• /
• v.28 no.1
• /
• pp.80-91
• /
• 2007

Objectives : Peroxynitrite (ONOO-), superoxide anion radical (?O2-) and nitric oxide (NO) are cytotoxic because they can oxidize several cellular components such as proteins, lipids and DNA. They have been implicated in the aging process, and age-related diseases such as Alzheimer's disease, rheumatoid arthritis, cancer and atherosclerosis. The aim of this study was to investigate Sabohwan's activity for scavenging ONOO- and its precursors. NO and ?02-. Methods : For this study, the fluorescent probes, namely 2',7'-dichlorodihydrofluorescein diacetate (DCFDA), 4.5-diaminofluorescein (DAF-2) and dihydrorhodamine 123 (DHR 123) were used. Results : Sabohwanblocked tert-butylhydroperoxide (t-BHP)-induced cell death in a dose-dependent fashion. It scavenged t-BHP-induced ONOO-, NO and ?O2- in YPEN cells. Sabohwan inhibited the generation of ONOO-, NO and ?O2- in the lipopolysaccharide (LPS)-treated mouse kidney postmitochondria both in vitro and in vivo. The lipid peroxide level increased and glutathione level decreased in the LPS-treated mice, whereas the ones in the Sabohwanadministered group among the LPS-treated mice reversed toward their natural levels. Conclusions : These results suggest that Sabohwanis an effective ONOO-, ?O2- and NO scavenger, and thereby it might have a potential role as a therapy against the aging process and age-related diseases.

• Biomolecules & Therapeutics
• /
• v.18 no.1
• /
• pp.77-82
• /
• 2010

Peroxisome proliferator-activated receptor $\gamma$ (PPAR${\gamma}$) is a ligand-activated transcription factor that is used as a target for anti-diabetic drug development. In a search for novel PPAR${\gamma}$ agonists, the $\beta$-carboxyethyl-rhodanine derivative SP1818 was identified. We report here the characteristics of SP1818 as a selective PPAR${\gamma}$ agonist. In transactivation assays, SP1818 selectively activated PPAR${\gamma}$, but the degree of PPAR${\gamma}$ stimulation was less than with $1{\mu}M$ rosiglitazone. SP1818 also stimulated glucose uptake in a concentration-dependent manner. The adipocyte differentiation markers adiponectin, scavenger receptor CD36 and aP2 were weakly induced by treatment with SP1818, and TRAP220 subunit was specifically recruited into PPAR${\gamma}$ activated by rosiglitazone but not PPAR${\gamma}$ activated by SP1818.

• Microbiology and Biotechnology Letters
• /
• v.18 no.1
• /
• pp.103-108
• /
• 1990

The enzymatic studies on the methylglyoxal metabolism in yeast and bacterial cells indicated that organisms are equipped with the common and manifold systems for the detoxification of methylglyoxal. Among these systems, the glyoxalase I is the most important route for methylglyoxal detoxification. The molecular structure of glyoxalase I is apparently distinct from the enzyme sources, and zinc ion is an essential cofactor in enzyme activity. The gene for Pseudomonas putida glyoxalase I functioned as a scavenger of methylglyoxal and regulated the cell size of the bacterium. Comparison of the nucleotide sequence of the P. putida glyoxalase I gene with the N-terminal amino acid sequence of the purified enzyme revealed that the N-terminal methionine residue was removed after translation. Possible physiological role of glyoxalase I was also discussed.

• Biomedical Science Letters
• /
• v.7 no.3
• /
• pp.99-102
• /
• 2001

Toluene is mainly metabolized in liver by oxidative pathway. Oxigen free radicals occur through the process of toluene metabolism Therefore it causes tissue and cell min by the oxygen free radicals from the metabolism of toluene. Melatonin acts as a highly efficient free radical scavenger that protects cells from damage by oxygen free radicals. To test this hypothesis, toluene hepatotoxicity was induced by an abdominal injection of toluene. To see if the melatonin protects the rat's liver, melatonin was administrated orally, at the time of each toluene injection. Aspartate aminotransferase(AST), alanin aminotransferase(ALT), latic dehydrogenase(LDH) and alkaline phosphatase(ALP) levels in serum were measured to estimate hepatic function. Malondialdehyde(MDA), which gives an indirect index of oxidative injury was also measured. Hippuric acid is the last metabolic Production of toluene was measured by HPLC. There were significantly higher in AST, ALT, LDH, MDA and hippuric acid in toluene group, but there were no significant difference in melatonin group except ALT and hippuric acid. There was significantly lower in ALP level in toluene group, but there was no significant difference melatonin group, suggesting a significant hepatotoxicity due to oxygen free radicals through the process of toluene metabolism Melatonin treatment significantly protected hepatic function and free radical-mediated injury in the liver against toluene-induced changes. Accordingly, this study shows that melatonin is helpful in protecting liver injury by acute toluene intoxication.

• BMB Reports
• /
• v.43 no.9
• /
• pp.622-628
• /
• 2010

Dimethyl sulfoxide (DMSO) can be reduced to dimethyl sulfide by MsrA, which stereospecifically catalyzes the reduction of methionine-S-sulfoxide to methionine. Our previous study showed that DMSO can competitively inhibit methionine sulfoxide reduction ability of yeast and mammalian MsrA in both in vitro and in vivo, and also act as a non-competitive inhibitor for mammalian MsrB2, specific for the reduction of methionine-R-sulfoxide, with lower inhibition effects. The present study investigated the effects of DMSO on the physiological antioxidant functions of methionine sulfoxide reductases. DMSO elevated hydrogen peroxide-mediated Saccharomyces cerevisiae cell death, whereas it protected human SK-Hep1 cells against oxidative stress. DMSO reduced the protein-carbonyl content in yeast cells in normal conditions, but markedly increased protein-carbonyl accumulation under oxidative stress. Using Msr deletion mutant yeast cells, we demonstrated the DMSO's selective inhibition of the antioxidant function of MsrA in S. cerevisiae, resulting in an increase in oxidative stress-induced cytotoxicity.

• Environmental Analysis Health and Toxicology
• /
• v.10 no.1_2
• /
• pp.47-54
• /
• 1995

To investigate and evaluated the scavenging and antioxidative effects of various flavonoids on paraquat induced toxicity, in vivo and vitro tests of eight flavonoids (catechin, epocatechin, flavone, chrysin, apigenin, quercetin, morin and biochanin A) were carried out. The generation of reactive oxygen substances(ROS) in PMS-NADH system $H_2O_2$ induced hemolysis and lipidperoxidation to blood, NADPH dependent lipidperoxidation to liver and lung microsome by paraquat were studied.The results are summerized as follows; 1) In the concentration ranges from 3.3 to 9.8$\mu$M of catechin,epicatechin, quercetin and biochanin A removed the 50% of DPPH radical scavenging effects. 2) In the concentration ranges from 0.60 to 1.86 mM of catechin, epicatechin, quercetin and biochanin A showed the inhibitory and antioxidative activity on superoxide anion which gernerated in PMA-NADH system. 3) In the concentration ranges from 0.12 to 0.49mM of catechin, epicatechin, quercetin and biochanin A showed the inhibitory and antioxidative activity on H202 which generated in PMA-NADH system. 4) In the concentration ranges from 0.6 x10$^{-5}$ to 6.3 x 10$^{-5}$mM of catechin, epicatechin, flavone, chrysin, quercetin and morin showed the inhibitory and antioxidative activity on $H_2O_2$ induced hemolysis to blood 5) All flavonoids tested exhibited inhibitory and antioxidative effects on paraquat induced liver and tung microsomal lipidperoxidation. Therefore, all flavonoids evaluated showed the useful compounds for scavenger and antioxidant on paraquat induced toxicity.

• Clinical and Experimental Pediatrics
• /
• v.59 no.10
• /
• pp.395-401
• /
• 2016

Since the outbreak of the enterovirus 71 (EV71) infection in Malaysia in 1997, large epidemics of EV71 have occurred in the Asia-Pacific region. Many children and infants have died from serious neurological complications during these epidemics, and EV71 infection has become a serious public health problem in these areas. EV71 infection causes hand, foot and mouth disease (HFMD) in children, and usually resolves spontaneously. However, EV71 occasionally involves the central nervous system (CNS), and induces diverse neurological complications such as brainstem encephalitis, aseptic meningitis, and acute flaccid paralysis. Among those complications, brainstem encephalitis is the most critical neurological manifestation because it can cause neurogenic pulmonary hemorrhage/edema leading to death. The characteristic clinical symptoms such as myoclonus and ataxia, cerebrospinal fluid (CSF) pleocytosis, and brainstem lesions on magnetic resonance imaging, in conjunction with the skin rash of HFMD and the isolation of EV71 from a stool, throat-swab, or CSF sample are typical findings indicating CNS involvement of EV71 infection. Treatment with intravenous immunoglobulin and milrinone are recommended in cases with severe neurological complications from EV71 infection, such as brainstem encephalitis. Despite the recent discovery of receptors for EV71 in human cells, such as the scavenger receptor B2 and P-selection glycoprotein ligand 1, it is not known why EV71 infection predominantly involves the brainstem. Recently, 3 companies in China have completed phase III clinical trials of EV71 vaccines. However, the promotion and approval of these vaccines in various countries are problems yet to be resolved.

• The Plant Pathology Journal
• /
• v.36 no.2
• /
• pp.121-132
• /
• 2020

β-Aminobutyric acid (BABA) has consistently been reported to enhance plant immunity. However, the specific mechanisms and downstream components that mediate this resistance are not yet agreed upon. Nitric oxide (NO) is an important signal molecule involved in a diverse range of physiological processes, and whether NO is involved in BABA-induced resistance is interesting. In this study, treatment with BABA significantly increased NO accumulation and reduced the sensitivity to Botrytis cinerea in tomato plants. BABA treatment reduced physical signs of infection and increased both the transcription of key defense marker genes and the activity of defensive enzymes. Interestingly, compared to treatment with BABA alone, treatment with BABA plus cPTIO (NO specific scavenger) not only significantly reduced NO accumulation, but also increased disease incidence and lesion area. These results suggest that NO accumulation plays an important role in BABA-induced resistance against B. cinerea in tomato plants.

• Toxicological Research
• /
• v.23 no.3
• /
• pp.215-221
• /
• 2007

Although sanguinarine, a benzophenanthridine alkaloid, possesses anti-cancer properties against several cancer cell lines, the molecular mechanisms by which it inhibits cell growth and induces apoptosis have not been clearly understood. In order to further explore the critical events leading to apoptosis in sanguinarine-treated MCF-7 human breast carcinoma cells, the following effects of sanguinarine on components of the mitochondrial apoptotic pathway were examined: generation of reactive oxygen species (ROS), alteration of the mitochondrial membrane potential (MMP), and the expression changes of Bcl-2 family proteins. We show that sanguinarine-induced apoptosis is accompanied by the generation of intracellular ROS and disruption of MMP as well as an increase in pro-apoptotic Bax expression and a decrease of anti-apoptotic Bcl-2 and Bcl-xL expression. The quenching of ROS generation with N-acetyl-L-cysteine, the ROS scavenger, protected the sanguinarine-elicited ROS generation, mitochondrial dysfunction, modulation of Bcl-2 family proteins, and apoptosis. Based on these results, we propose that the cellular ROS generation plays a pivotal role in the initiation of sanguinarine-triggered apoptotic death.

• Biomolecules & Therapeutics
• /
• v.6 no.3
• /
• pp.261-268
• /
• 1998

Propolis is a lipophilic, natural product prepared by mixing the exudates collected from various plants by honeybees with beeswax for the purpose of using to seal hive walls and to strengthen the borders of combs. Because of its versatile bioactivities, propolis has been attracting many investigators'interest. But the pharmacological studies on propolis has, to date, been exclusively performed for an alcohol extract, there is few information of water extract. Therefore, in this study, we investigated the various effects of water extract of Chinese propolis. The water extract of propolis and its fractions of organic solvents showed strong antioxidative activities, especially ether and ethylacetate fractions, and reduced the lipid peroxidation of rat liver in viro. Additionally the ether fraction of propolis (10 mg/ml) inhibited the activity of hyaluronidase by 50%. In vivo, the water extract of propolis considerably decreased s-GOT, s-GPT and s-LDH activities which represent for the hepatotoxicity induced by $CCl_4$ in rats, and prolonged the MST (Medium revival tinge) and ILS (Increasing in MST over control) by 18% in mice which inoculated with sarcoma 180 ascites cells. These results suggest that the water extract of propolis has various bioactivities as well as the alcohol extract.