• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.105-113
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• 2014

Objectives: It is necessary to apply quantitative structure activity relationship (QSAR) for the various chemicals with insufficient toxicity data that are used in the workplace, based on the precautionary principle. This study aims to find application plan of QSAR software tool for predicting health hazards such as genetic toxicity, and carcinogenicity for some chemicals used in the electronics industries. Methods: Toxicity prediction of 21 chemicals such as 5-aminotetrazole, ethyl lactate, digallium trioxide, etc. used in electronics industries was assessed by Toxicity Prediction by Komputer Assisted Technology (TOPKAT). In order to identify the suitability and reliability of carcinogenicity prediction, 25 chemicals such as 4-aminobiphenyl, ethylene oxide, etc. which are classified as Group 1 carcinogens by the International Agency for Research on Cancer (IARC) were selected. Results: Among 21 chemicals, we obtained prediction results for 5 carcinogens, 8 non-carcinogens and 8 unpredictability chemicals. On the other hand, the carcinogenic potential of 5 carcinogens was found to be low by relevant research testing data and Oncologic TM tool. Seven of the 25 carcinogens (IARC Group 1) were wrongly predicted as non-carcinogens (false negative rate: 36.8%). We confirmed that the prediction error could be improved by combining genetic toxicity information such as mutagenicity. Conclusions: Some compounds, including inorganic chemicals and polymers, were still limited for applying toxicity prediction program. Carcinogenicity prediction may be further improved by conducting cross-validation of various toxicity prediction programs, or application of the theoretical molecular descriptors.

• CELLMED
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• v.6 no.2
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• pp.12.1-12.7
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• 2016

Cocos nucifera (C. nucifera) oil is indigenously used to treat cardiovascular diseases. However, coconut husk fibre (which is rich in polyphenols) has not been screened for this property. Based on the ethnomedicinal use of polyphenols in treating cardiovascular diseases, this study was carried out to evaluate the effects of polyphenols of C. nucifera husk fibre on selected cardiovascular disease indices in mice. Fifty adult male Swiss albino mice were assigned randomly into five groups (A-E). Mice in groups B, C, D and E were administered 31.25, 62.5, 125, and 250 mg/kg body weight polyphenols of ethyl acetate extract of C. nucifera husk fibre respectively while the control group (A) mice received 5% DMSO for seven days. The mice were sacrificed twenty four hours after the last administration of polyphenols. Heart and plasma lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities and plasma lipid profile were determined. Results revealed significant reduction (^*p< 0.05) in plasma levels of total cholesterol and LDL-cholesterol with no significant change (^*p> 0.05) in HDL-cholesterol, triglyceride and VLDL levels in the plasma at all doses of polyphenols administered compared to controls. There was significant reduction (^*p< 0.05) in the activities of heart AST and LDH while plasma ALT, AST, and ALP activities were not significantly altered (^*p> 0.05) at all doses of polyphenols administered compared to controls. These results suggest that the polyphenols of C. nucifera husk fibre possess cardio-protective properties and also indicate their possible use in the treatment of cardiovascular diseases.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.474-478
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• 1999

Modulation of unscheduled DNA synthesis by dehydroepiandrosterone (DHEA) after exposure to various chemical carcinogens was investigated in the primary rat hepatocytes. Unscheduled DNA synthesis was induced by treatment of such direct acting carcinogens as methly methanesulfonate (MMS) and ethyl methanesulfonate (EMS) or procarcinogens including benzo(a)pyrene (BaP) and 7, 12-dimethylbenz(a)anthracene (DMBA). Unscheduled DNA synthesis was determined by measuring [methyl-3H]thymidine radioactivity incorporated into nuclear DNA of hepatocytes treated with carcinogens in the presence or absence of DHEA. Hydroxyurea $(5{\times}10^{-3} M)$was added to growth medium to selectively suppress normal replication. DHEA at concentrations ranging from $(1{\times}10^{-6} M)$ to$(5{\times}10^{-4} M)$ did not significantly inhibit unscheduled DNA synthesis induced by either MMS $(1{\times}10^{-4} M)$ or EMS $(1{\times}10^{-2} M)$. In contrast, DHEA-significantly inhibited unscheduled DNA synthesis induced by BaP $(6.5{\times}10^{-5} M)$ and DMBA.$(2{\times}10^{-5} M)$. DHEA-induced hepatotoxicity in rats was examined using lactate dehydrogenase (LDH) release as an indicator of cytotoxicity. DHEA exhibit no significant increase in LDH release compared with the control at 18 h. These data suggest that nontoxic concentration of DHEA does not affect the DNA excision repair process, but it probably influence the enzymatic system responsible for the metabolic activation of procarcinogens and thereby decreases the amount of the effective DNA adducts formed by the ultimate reactive carcinogenic species.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.283-290
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• 2020

Oxidative stress is one of the contributors of neurodegenerative disorders including Alzheimer's disease. According to previous studies, Aster yomena (Kitam.) Honda (AY) possesses variable pharmacological activities including anti-coagulant and anti-obesity effect. In this study, we aimed to determine the neuroprotective effect of ethyl acetate fraction from Aster yomena (Kitam.) Honda (EFAY) against oxidative stress. Therefore, we carried out 3-(4,5-dimethylthiazol-2-yl)-2,3-diphenyl tetrazolium bromide, lactate dehydrogenase (LDH), and 2',7'-dichlorofluorescin diacetate assays in SH-SY5Y neuronal cells treated with hydrogen peroxide (H₂O₂). H₂O₂-treated control cells exhibited reduced viability of cells, and increased LDH release and reactive oxygen species (ROS) production compared to normal cells. However, treatment with EFAY restored the cell viability and inhibited LDH release and ROS production. To investigate the underlying mechanisms by which EFAY attenuated neuronal oxidative damage, we measured protein expressions using Western blot analysis. Consequently, it was observed that EFAY down-regulated cyclooxygenase-2 and interleukin-1β protein expressions in H₂O₂-treated SH-SY5Y cells that mediated inflammatory reaction. In addition, apoptosis-related proteins including B-cell lymphoma-2-associated X protein/B-cell lymphoma-2 ratio, cleaved caspase-9, and cleaved-poly (ADP-ribose) polymerase protein expressions were suppressed when H₂O₂-treated cells were exposed to EFAY. Our results indicate that EFAY ameliorated H₂O₂-induced neuronal damage by regulating inflammation and apoptosis. Altogether, AY could be potential therapeutic agent for neurodegenerative diseases.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.357-363
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• 2020

Oxidative stress caused by the overproduction of reactive oxygen species (ROS) is known as an etiology of neurodegenerative diseases. Populus tomentiglandulosa (PT), a member of the Salicaceae family, is widely grown in Korea and has been reported to exert protective effects on cerebral ischemia by attenuating of oxidative stress and neuronal damage. In the present study, we investigated the antioxidant activity and neuroprotective effects of an ethanol extract and four fractions [n-butanol, ethyl acetate (EtOAc), chloroform, and n-hexane] of PT under in vitro and cellular systems. The extract and four fractions of PT showed 1,1-diphenyl-2-picrylhydrazyl (DPPH), •OH, and O2- radical scavenging activities in a dose-dependent manner. In particular, the EtOAc fraction of PT had the strongest DPPH, •OH, and O2- radical scavenging activities among the extract and other fractions. Therefore, we further investigated the neuroprotective effect of the EtOAc fraction of PT against oxidative stress in H2O2-induced SH-SY5Y cells. Treatment with H2O2 significantly decreased cell viability and lactate dehydrogenase (LDH) release, and it also increased the ROS levels compared to the normal group. However, treatment with the EtOAc fraction of PT significantly increased cell viability. Moreover, the EtOAc fraction of PT-treated group significantly suppressed ROS production and LDH release compared to the H2O2-induced control group. In conclusion, our findings indicated that PT had in vitro antioxidant activity and neuroprotective effects against oxidative stress. Therefore, PT could be used as a natural agent for protection against oxidative stress.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.483-488
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• 2014

To examine the physiological effects of broccoli (Brassica oleracea var. italica) leaf, the bioavailable compounds in broccoli leaf extract, and its in vitro neuroprotective effects against $H_2O_2$-induced oxidative stress were examined in this study. The chloroform fraction of broccoli leaf extract had the highest total phenolic content of all the fraction than others, and the highest 2,2"-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging activity and malondialdehyde (MDA) inhibitory effect. Intracellular reactive oxygen species (ROS) accumulation resulting in $H_2O_2$-treated in PC12 cells was significantly lower when the chloroform fraction was present in the medium compared to that in PC12 cells treated with $H_2O_2$ alone. In a cell viability assay performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), the chloroform fraction showed protective effects against $H_2O_2$-induced neurotoxicity and inhibited lactate dehydrogenase (LDH) release into the medium. High-performance liquid chromatography (HPLC) analysis showed that ferulic acid was the predominant phenolic compound in chloroform fraction of broccoli leaf.

• Food Science and Preservation
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• v.18 no.3
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• pp.358-365
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• 2011

The antioxidant and neuronal cell-protective effects of hot water extract from commercial buckwheat tea (CBTE) were evaluated. The 2,2'-azino-bis(3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, ferric reducing antioxidant power (FRAP), and malondialdehyde (MDA) inhibitory effect of the CBTE increased in a dose-dependent manner. The Intracellular reactive oxygen species (ROS) accumulation that resulted from hydrogen peroxide ($H_2O_2$) treatment more significantly decreased when CBTE was present in the media than when the PC12 cells were treated only with $H_2O_2$. In the neuronal cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT), the aqueous extracts showed a protective effect against $H_2O_2$-induced neurotoxicity, and the lactate dehydrogenase (LDH) release into the medium was also inhibited by CBTE. The total phenolics of CBTE was 9,608.10 mg/100 g, and the major phenolic compounds were rutin (13.42 mg/100 g) and quercitrin (0.90 mg/100 g). These data suggested that CBTE, including the aforementioned phenolics, may be useful in reducing the risk of neurodegenerative disease.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.430-437
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• 2017

The protective effect of Pteridium aquilinum on high glucose-induced cytotoxicity was examined in vitro to investigate the relationship between diabetic condition and neuronal dysfunction. The ethyl acetate fraction of P. aquilinum (EFPA), with total phenolic content of 265.08 mg gallic acid equivalent/g, showed higher 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)/2,2-diphenyl-1-picrylhydrazyl radical scavenging activities and lipid peroxidation inhibitory effect than any other fraction. In addition, EFPA showed a significant reduction in the inhibitory effect on ${\alpha}$-glucosidase activity ($IC_{50}$ value=$205.26{\mu}g/mL$) compared to the acarbose positive control. The anti-oxidative effect in PC12 cells, protective effects on high glucose-induced oxidative stress in neuronal cells, and neurotoxicity were measured using 2',7'-dichlorofluorescin diacetate, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide, and lactate dehydrogenase assays, respectively. EFPA showed conspicuous inhibitory effect on cellular reactive oxygen species production and neuronal cell apoptosis. Finally, kaempferol-3-glucoside was identified as the main phenolic compound of EFPA using high performance liquid chromatography.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.106-111
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• 2005

To investigate the antioxidant activity of extract from the raw walnut, Juglans sinensis Dode, we prepared five fractions (methanol (MeOH), dichloromethane $(CH_2Cl_2)$, ethyl acetate (EtOAc), n-buthanol (n-BuOH) and dehydrogen monooxide $(H_2O)$ fractions) and examined. The effect of walnut extract on the oxidative stress was investigated in vitro. The DPPH (2,2-Di (4-tert-octylphenyl)-1-picrylhydrazyl) free radical scavenging activity of extract from raw walnut was shown in the following order: $EtOAc\;fraction layer. The result showed that the highest activity $(0.56{\mu}g/ml,\;IC_{50}.)$ was observed in EtOAc fraction, whereas n-BuOH fraction, MeOH fraction, $CH_2O_2$ fraction and $H_2O$ layer of $IC_{50}$ were $2.34{\mu}g//ml,\;3.88{\mu}g/ml,\;8.06{\mu}g/ml,\;and\;8.19{\mu}g/ml$, respectively. The radical scavenging activity assay of each fraction showed that the antioxidative activity was observed in the following order: EtOAc fraction $(74.27\pm1.56\%)>MeOH\;fraction\;(60.76\pm3.4\%)>n-BuOH\;fraction\;(59.32\pm0.88\%)>H_2O\;layer\;(41.69\pm2.06\%)$. These results revealed that all fractions, except for $CH_2Cl_2$ fraction, showed high antioxidative activity. Furthermore, the peroxynitrite $(ONOO^-)$ scavenging activity was assayed in each fraction. The result showed that the $ONOO^-$ scavenging activity of EtOAc fraction, MeOH fraction and n-BuOH fraction from raw walnut was $95.14\pm0.36\%,\; 90.02\pm1.19\%\;and\;89.41\pm0.81\%$, respectively. The tert-butylhydroperoxide (t-BHP) treatment in vitro increased lactate dehydrogenase release and lipid peroxidation in renal cortical slices. Such changes were completely prevented by addition of MeOH fraction, EtOAc fraction and n-BuOH fraction of walnut. These results indicate that the walnut extract exerts the benedicial effect against t-BHP-induced cell injury and its effect may be due to antioxidant action. In addition, it is suggested that walnut extract might be developed as the effective scavenger for the prevention of oxidative stress.