• 대한의생명과학회지
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• 제8권2호
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• pp.83-88
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• 2002

To investigate the skin toxicity of xylene, xylene (25 mg/$\textrm{cm}^2$) has been sequentially applied to the rat skin for four days. On the light microscopic examination, epithelium was left out with infiltration of inflammatory cells in border with dermis, and formation of new epithelial layer was shown under the inflammatory zone. Application of xylene to the rat skin showed the marked rise of cutaneous xanthine oxidase activity whereas, He activities of oxygen free radical scavenging enzymes, superoxide dismutase and glutathione S-transferase, were significantly declined. Furthermore, the content of cutaneous glutathione was more and less decreased in rat skin applied with xylene. In conclusion, these results suggest that a part of oxygen free radical may be responsible for morphological changes in skin by applying xylene to the rat skin.

• Archives of Pharmacal Research
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• 제27권6호
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• pp.610-614
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• 2004

The in vitro antioxidant properties of some flavone-6(4)-carboxaldehyde oxime ether deriva-tives (Ia-f, lIa-f） were determined by their effects on the rat liver microsomal NADPH-dependent lipid peroxidation (LP） levels by measuring the formation of 2-thiobarbituric acid reactive substances. The free radical scavenging properties of the compounds were also examined in vitro by determining their capacity to scavenge superoxide anions and interact with the stable free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH). The most active compounds, lib (Flavone-4＇-carboxaldehyde-O-ethyl oxime） and Id (Flavone-6-carboxaldehyde-O-［2-(1-pyrolidino） ethyl］ oxime）, caused 98 and 79％ inhibition of superoxide anion production and DPPH stable free radical at $10^{-3}{\;}M$, respectively.

• Biomolecules & Therapeutics
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• 제13권3호
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• pp.150-155
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• 2005

The ethanolic extract of chestnut (Castanea crenata S. et Z., Fagaceae) inner shell (CISE) and one of its components, ellagic acid (EA), were evaluated for their protective effects against 1, 1-diphenyl-2-picryl hydrazine (DPPH) free radical generation and hydrogen peroxide-induced oxidative DNA damage in a mammalian cell line. CISE and EA were shown to possess the free radical scavenging effect against DPPH radical generation, significantly. They were also found to strongly inhibit hydrogen peroxide-induced DNA damage from Chinese hamster lung (CHL) cell, assessed by single cell gel electrophoresis assay and 8-hydroxy -2'-deoxy guanosine (8-OH-2'dG) assay. Furthermore, topical application of CISE [$12.5\%$(w/w) cream] and ellagic acid [$1.0\%$(w/w) cream] for 14 days potently inhibited malondialdehyde (MDA) formation of mouse dorsal skin (a marker of lipid peroxidation) induced by ultraviolet B exposure. Therefore, CISE and its component, ellagic acid, may be the useful natural antioxidants by scavenging free radicals, inhibition of lipid peroxidation and protecting oxidative DNA damage when topically applied.

• 대한화학회지
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• 제15권4호
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• pp.177-181
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• 1971

Free radicals of lysozyme produced by $Ti-H_2O_2$ system were studied in aqueous solution at room temperature using ESR with a continuous flow-mixing. The spectra, each consisting of a doublet with 5.5 G splitting and a broad resonance covering 80 G splitting are closely similar in shape to that for solid irradiated in vacuum at $77^{\circ}K$ and observed at room temperature immediately on warming. The result is assumed to indicate that the secondary protein radical components formed within 0.01 second, dead time of the mixing chamber, and initiated by hydrogen atom abstraction at ${\alpha}$-carbon atom of peptide chain in liquid solution at room temperature are identical to those resulting from the initial formation of a mixture of positive holes and negative ions by ionization processes as well as radical fragments by the rupture of chemical bonds in the solid during similar time at the same temperature. A broad resonance is observed with considerable amplitude on the high field side of the doublet, which is quite dissimilar to the spectra of irradiated solid lysozyme. This resonance was tentatively attributed to the polypeptide free radical in which unpaired electrons are localized on side chain.

• Advances in Traditional Medicine
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• 제8권1호
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• pp.59-66
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• 2008

This study was undertaken to evaluate the antioxidant potential of A. lanata on oxalate mediated free radical toxicity in ethylene glycol induced calcium oxalate urolithic rats. Calcium oxalate (CaOX) stone was induced by 0.75% ethylene glycol in drinking water for 28 days. From $29^{th}$ day onwards, the CaOX urolithic rats were treated with A. lanata aqueous suspension (2,000 mg/kg body weight/dose/day) orally for another 28 days. At the end of experimental periods the animals were sacrificed, samples were collected and analyzed the lipid peroxidation product, protein oxidation product, enzymatic and non-enzymatic antioxidants in normal and experimental groups. Lipid peroxidation and protein oxidation products were significantly elevated while enzymatic and non-enzymatic antioxidant levels were significantly decreased in ethylene glycol induced CaOX urolithic rats when compared with control rats. The above alterations were reverted to near control in rats treated with aqueous suspension of A. lanata. This study suggests that A. lanata could prevent the free radical formation from calcium oxalate urolithiasis in rats and protecting the renal cells from oxidative injury.

• 약학회지
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• 제38권6호
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• pp.786-790
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• 1994

The crude alkaloidal fraction of the root of Cynanchum caudatum Max.(Asclepiadaceae) was tested for the effects on the activities of free radical generating enzymes and the formation of lipid peroxide. Aldehyde oxidase was strongly inhibited to about 90% of the activity by treating 1.0 mg/ml of alkaloidal fraction, corresponding to competitive inhibition. Moreover, the formation of lipid peroxide which causes damage of cell membrane was reduced in proportion to the increasing alkaloid concentration. However, xanthine oxidase of which structure and function are similar to those of aldehyde oxidase was not inhibited by the alkaloidal fraction.

• 대한환경공학회지
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• 제31권8호
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• pp.627-634
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• 2009

본 연구는 염화 이온 ($Cl^-$)을 전해질로 이용하는 전기화학적 공정에서 생성되는 염소산화부산물인 클로레이트 ($ClO_3\;^-$, 염소산염)의 생성 메커니즘을 알아보기 위해 수행되었다. 우선, pH 및 초기농도에 따른 생성 특성을 살펴보았으며, 유리염소 생성과의 관련성 및 오존, OH 라디칼 등의 혼합산화제의 영향을 간접 평가하여 클로레이트의 생성 메커니즘을 구체화하였다. 그 결과, 클로레이트의 생성은 유리염소 (HOCl/$OCl^-$)의 전기화학적 반응을 주된 반응으로 하며, 염화 이온의 직접 양극산화 반응 및 OH 라디칼에 의한 경로가 있음을 확인하였다. 이어서 생성된 클로레이트가 퍼클로레이트로 산화되는 반응도 볼 수 있었다. 또한, 전극 간격에 따른 생성 농도를 유리염소 생성과 함께 평가하여, 유리염소 생성 효율은 극대화 시키되 클로레이트의 발생을 최소화 할 수 있는 최적조건을 찾는 방안을 제시하였다.

• 약학회지
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• 제38권2호
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• pp.166-173
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• 1994

Sex hormones not only regulate external sexual characteristics but several internal biochemical processes. It is well accepted that life-span of female is longer than that of male. Life-span is closely related with aging process in which free radicals are known to be involved. We investigated the effect of testosterone on free radical generating systems and lipid peroxidation based on the sexual difference. Lipid peroxide levels of male and female mouse were increased proportionately with age, especially in male mouse. Increase in enzyme activity of aldehyde oxidase with age was observed in male mouse, while no siginificant change in enzyme activity was found in female mouse. Enzyme activity of xanthine oxidase also showed similar results. It, however, was not significant statistically. Lipid peroxide level and xanthine oxidase type conversion ratio of male and female mouse liver homogenate incubated at $37^{\circ}C$, increased remarkably in proportion to incubation time, especially in male mouse. Lipid peroxide level and aldehyde oxidase activity were measured in normal male mouse, castrated mouse and testosterone treated-castrated mouse. Castrated mouse group showed decrease in lipid peroxide level and aldehyde oxidase activity compared with normal group. Treatment of castrated mouse with testosterone, however turned the level of lipid peroxide and aldehyde oxidase activity back to normal. From the above results, it might be concluded that testosteron could increase the activities of free radical generating enzymes which would result in the formation of lipid peroxide, consequently leading to aging.

• 대한한의학회지
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• 제32권1호
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• pp.109-120
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• 2011

Objectives: The aim of this investigation was to evaluate the efficacy of KHchunggan-tang aqueous extract on the experimental nonalcoholic fatty liver disease(NAFLD) induced by palmitate. Materials and Methods: To generate a cellular model of NAFLD, we used HepG2 cells, a human hepatoma cell line, treated with 0.5 mM palmitate. By this cellular model, effects of KHchunggan-tang aqueous extract were evaluated. Intracellular lipid accumulation, free radical formation, and apoptosis were detected by Nile red staining, 2',7'-dichloroflourescin diacetate(H2DCF-DA), and 4',6-diamidino-2-phenylindole(DAPI)/propidium iodide(PI) staining, respectively. Some proteins related with NAFLD were determined by western blot. Results: Typical pathological features of NAFLD occurred in the cellular model. Palmitate increased the levels of intracellular lipid vacuoles, decreased cell viability, and increased apoptosis. Palmitate increased free radical formation and lipid peroxidation, too. However, KHchunggan-tang aqueous extract reduced palmitate-induced pathologic features, i.e. steatosis, free radical formation, and apoptosis. In addition, KHchunggan-tang aqueous extract suppressed palmitate-activated c-Jun N-terminal kinase(JNK) signaling, and SP600125, a JNK inhibitor, significantly reversed the palmitate-induced pathologic changes as KHchunggan-tang aqueous extract. It means that the signaling pathway other than JNK can be involved in the KHchunggan-tang mediated cellular protection of palmitate-treated Hep G2 cells. Conclusions: These results suggest that KHchunggan-tang aqueous extract has hepatoprotective effects on NAFLD with combined properties in cellular steatosis, ROS production, and cytoprotection, and thus may have valuable clinical applications for treatment of this chronic liver disease.

• 생약학회지
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• 제32권2호통권125호
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• pp.163-167
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• 2001

Prunella vulgaris L. aqua-acupuncture solution (PVAS) was tested for cancer chemopreventive activity using chemoprevention-associated biochemical end points. The following effects were measured. : (a) inhibition of 7,12-dimethylbenz[a]anthracene (DMBA)-induced cytochrome P4501A1 activity (b) inhibition of $[^3H]B[a]P-DNA$ binding (c) inhibition of phorbol 12-myristate 13-acetate (TPA)-induced free radical formation in HL-60 cells (d) inhibition of polyamine metabolism. PVAS inhibited cytochrome P4501A1-mediated ethoxyresorufin-O-deethylase activity. The binding of $[^3H]B[a]P$ metabolites to DNA of NCTC-clone 1469 cells was inhibited significantly by PVAS. There is 22% inhibition of TPA-induced free radical formation in human leukemic cells with 5 mg/ml PVAS. Proliferation of Acanthamoeba castellanii was inhibited by PAVS at concentration of 30 mg/ml. PAVS positive in these assays may inhibit the carcinogenesis process and is considered very promising cancer-preventing agent because of its multiple activities.