• Toxicological Research
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• v.3 no.2
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• pp.97-110
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• 1987

The effects of 5 novel hepatotrophic agents, dithiol malonate derivatives (DMDs; DMD1-DMD5), on the liver microsomal lipid peroxidation induced by carbon tetrachloride $(CCl_4)$ and the correlations with the changes of microsomal electron transport system were investigated. All DMDs were found to inhibit the lipid peroxidation induced by $CCl_4$ in mice and rats as well in vitro liver microsomal system. Therefore, each DMD seemed to have direct mode of action on liver microsomes to inhibit the lipid peroxidation. As an ex vivo study, the induced lipid peroxidation by $CCl_4$ and the changes in electron transport system were determined with liver microsomes obtained from rats chronically treated with DMDs for 7 days. The induced lipid peroxide contents in liver microsomal system were lower in DMD1, DMD2 and DMD3 treated group, but higher in DMD4 and DMD5 group when compared to the control group. Cyt. p.450 contents in the microsomes were decreased by the treatment with DMD1, DMD2 and DMD3, but increased significantly by DMD4 with great extent and by DMD5 with less extent. The cyt. p-450 isozymes induced by treatment of DMD4 and DMD5 were identified as 3-methylcholanthrene (MC) type. The NADPH cyt. -C reductase activities of the microsomes treated with DMD1, DMD2, DMD4 and DMD5 were increased in the range of around 20% to 50%, but decreased with DMD3, All DMDs increased dyt. $-b_5$ content and did not alter NAdH-cyt, $-b_5$ reductase activities in the microsomes. In summary, the 5 novel hepatotrophic agents (DMDs) markedly protected against lipid peroxidation induced by $CCl_4$ in vivo and in vitro possibly through the mechanism of direct action on the liver microsomes. The degree of inhibition produced by DMDs on lipid peroxidation induced by $CCl_4$ seemed to coincide rather with cyt. p-450 contents than with other components of liver microsomal electron transport system including NADPH-cyt, -C reductase.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.419-430
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• 1987

The damage of plasmid DNA by lipid peroxidation and its inhibition were investigated through the model system of DNA and linoleic acid at $37^{\circ}C$. The degree of DNA damage increased in proportion to the increase of concentration and peroxidation of linoleic acid. DNA damage induced from linoleic acid peroxidation was greatly inhibited by the addition of active oxygen scavengers, especially, singlet of oxygen scavenge$(\alpha-tocopherol,\;cysteine)$ and superoxide anion scavenger(superoxide dismutase, ascorbic acid) in reaction system. These active oxygens, such as superoxide anion and hydrogen peroxide were rapidly generated in the early stage of peroxidation (POV below 100 mg/kg) and also scanvenged by the addition of superoxide dismutase and catalase, respectively. Hydroperoxide isolated from autoxidised linoleic acid showed DNA damage. Hydroperoxide induced-DNA damage was not inhibited by active oxygen scavengers. Lipid oxidation products, malonaldehyde and hexanal, also influenced on the DNA damage. Accordingly, it is speculated that DNA damage by lipid oxidation products is due to active oxygens such as singlet oxygen and superoxide anion formed in the early stage of peroxidation, direct action of hydroperoxide and formation of low molecular carbonyl compound-DNA complex. Furthermore, DNA damage induced by lipid peroxidation was remarkably inhibited by the addition of active oxygen scavengers and natural antioxidative fractions extracted from garlic and ginger. These antioxidative fractions also suppressed the generation of active orygens and linoleic acid oxidation. It is assumed that the inhibition of DNA damage by garlic and ginger extracts is due to the scavenging effect of active oxygens and the inhibition of hydroperoxide and oxidation products formation.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.363-371
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• 2015

n-Butanol and ethyl acetate extracts of thermal treatment yam (Dioscorea batatas $D_{ECNE.}$) belonging to the family Dioscoreaceae were measured for their radical scavenging activity and lipid peroxidation inhibition ability. In this study, ethyl acetate extract showed the most potent antioxidant activity evaluated by ferrous ion chelating activity and NO radical scavenging activity. Nevertheless, n-butanol extract was more effective in inhibiting linoleic acid peroxidation. A significant difference between n-butanol extract and ethyl acetate extract in nitrite scavenging activity ${\beta}$-carotene bleaching assays could not be found. Also, the results of this study showed that thermal treatment yam could be used as easily accessible source of natural antioxidants and as a possible food supplement.

• YAKHAK HOEJI
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• v.44 no.3
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• pp.257-262
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• 2000

The roots of Cynanhum caudatum (Asclepiadaceae) have been used in folk medicine in Japan and China for the prevention and treatment of various geriatric diseases and also as a cardiotonic agent. Constituents of this plant have mainly been examined for glycosides: besides two steroidal alkaloids, gagaminine and gagamine which was firstly isolated by us, more than 35 polyoxypregnane glycosides and aglycones have also been identified. Gagaminine inhibits potently the hepatic aldehyde oxidase activity and lipid peroxidation in vitro. The present work deals with the comparison of antioxidative activities of gagamine, a new pregnane alkaloid, three isolated polyoxypregnanes containing a keto group at C-20 with those of gagaminine, a potent antioxidant, in order to explain the structure-activity relationships. The results of this study further prove that the cinnamoyl group of gagaminine is very important for the inhibition on the aldehyde oxidase activity while the nicotinoyl group is necessary for anti-lipid peroxidation. Besides that, the keto compounds having no ester group at C-12 were found to be more active than the others except gagaminine.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.273-277
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• 1998

In order to determine the structure-activity relationships for antioxidative effects of gagaminine, a steroidal alkaloid isolated from the roots of Cynanchum wilfordi (Asclepiadaceae), two derivatives identified as sarcostin and penupogenin were prepared from gagaminine by hydrolysis and reduction. These compounds were evaluated for the inhibitory effects on the aidehyde oxidase activity and on lipid perbxidation in vitro. Furthermore, their effects were compared with those of gagaminine and the related compounds, cinnamic acid and nicotinic acid. The results of this study prove that the cinnamoyl group in the structure of gagaminine is critical in inhibition of the aldehyde oxidase activity while the nicotinoyl group may be necessary for anti-lipid peroxidation of the compound.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.712-717
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• 1998

This study was undertaken to investigate the inhibition effects of Auricularia auricula-judae methanol extract in edible mushroom on lipid peroxidation and liver damage in benzo(a)pyrene(B(a)P)-treated mice. The activities of serum aminotransferase, cytochrome P-450, superoxide dismutase, catalase, glutathione peroxidase and the hepatic content of lipid peroxide after B(a)P-treatment was markedly increased than control but those levels were significantly decreased by the treatment of Auricularia auricula-judae methanol extract. Glutathione S-transferase activity and the hepatic glutathione content were decreased by B(a)P-treatment than control, but those were also inhibited by the treament of Auricularia auricula-judae methanol extract. These results suggest that Auricularia auricula-judae methanol extract have a protective effect on liver damage by B(a)P.

• Journal of Applied Biological Chemistry
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• v.51 no.3
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• pp.111-116
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• 2008

Aralia elata seeds were successively extracted with water, methanol, ethanol, acetone and chloroform. The crude extracts were investigated for antioxidant and antidiabetic activities. The antioxidant properties of various extracts were evaluated by antioxidant tests, such as DPPH free radical-scavenging activity, hydroxyl radical-scavenging assay, metal-chelating activity, lipid peroxidation inhibition activity and reducing power assay. The 70% methanol extract exhibited the highest activity in the in vitro models of DPPH free radical-scavenging activity, metal-chelating activity, and reducing power assay. Acetone extract showed good effects on lipid peroxidation inhibition and hydroxyl radical-scavenging assay at a low concentration. In addition, the $\alpha$-glucosidase inhibition assay showed that 70% methanol extract had the highest activity. These results indicate the high possibility of using A. elata seeds for medical application due to their efficient antioxidant properties.

• Journal of Life Science
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• v.8 no.4
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• pp.464-471
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• 1998

This study was carried out to determine whether Kamihaengche-tang plus Yukmijihwang-tang (KCYH) exerts the protective effect against oxidant-induced liver cell injury. Cell injurt was estimated by measuring lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) release, and lipid peroxidation was estimated by measuring malondialdehyde, a product of lipid peroxidation in rabbit liver slices. $H_2O_2$increased LDH release which was significantly prevented by 1% KCYHT. The protective effect of KCYH against $H_2O_2$-induced cell injury was dose-dependent in the range of 0.05-1% concentrations. Similary, KCYH inhibited $H_2O_2$ induced lipid peroxidation in a dose-dependent manner. When liver tissuse were exposed to Hg(0.5 mM), ALT activity in the medium and lipid erpoxidation in tissues were markedly increased. These changes were prevented by 1% KCYH. KCHY restored Hg-induced inhibition of cellular GSH content. These result indicate that KCYH exerts the protective effect oxidant-induced liver cell injury, and this effect is attributed to prevented to prevention of lipid peroxidation. These dffects may be due to an increase in concentration of endogenous antioxidants.

• Preventive Nutrition and Food Science
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• v.16 no.3
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• pp.224-229
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• 2011

The radical scavenging activity and inhibition effect from lipid peroxidation induced by peroxyl radical of methanol extract from Perilla frutescens and its active compound, rosmarinic acid (RA), were investigated in vitro. The treatment of extract and RA scavenged 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radical (${\cdot}OH$) and nitric oxide in a concentration-dependent manner. In particular, the extract and RA showed strong radical scavenging activity against ${\cdot}OH$, the most toxic and reactive radical. In addition, Perilla frutescens and RA effectively inhibited lipid oxidation induced by sodium nitroprusside and 2,2'-azobis(2-aminopropane) dihydrochloride, determined by the ferric thiocyanate method. The present results suggest that Perilla frutescens and RA play a protective role against oxidative stress induced by free radical and lipid peroxidation.

• YAKHAK HOEJI
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• v.44 no.4
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• pp.354-357
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• 2000

Two ellagitannins, pedunculagin and 2,3-(S)-Hexahydroxydiphenoyl (HHDP)-D -glucose and three condensed tannins, (+)-catechin, (-)-epicatechin and procyanidin B-4 which were isolated from Rubus coreanum were evaluated for their antioxidative effects with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation generation system mediated by addition of $H_2O$$_2$to rat liver homogenate (TBARS). The ellagitannins, 2,3-(S)-HHDP-D-glucose and pedunculagin, showed more potent antioxidative activities by DPPH and TBARS than condensed tannins.