• Title/Summary/Keyword: Oxidative addition

Search Result 1,245, Processing Time 0.025 seconds

Protective effect of Cordyceps militaris against hydrogen peroxide-induced oxidative stress in vitro

  • He, Mei Tong;Lee, Ah Young;Park, Chan Hum;Cho, Eun Ju
    • Nutrition Research and Practice
    • /
    • v.13 no.4
    • /
    • pp.279-285
    • /
    • 2019
  • BACKGROUND/OBJECTIVES: Excessive production of reactive oxygen species (ROS) such as hydroxyl (${\cdot}OH$), nitric oxide (NO), and hydrogen peroxide ($H_2O_2$) is reported to induce oxidative stress. ROS generated by oxidative stress can potentially damage glial cells in the nervous system. Cordyceps militaris (CM), a kind of natural herb widely found in East Asia. In this study, we investigated the free radical scavenging activity of the CM extract and its neuroprotective effects in $H_2O_2$-induced C6 glial cells. MATERIALS/METHODS: The ethanol extract of CM ($100-1,000{\mu}g/mL$) was used to measure DPPH, ${\cdot}OH$, and NO radical scavenging activities. In addition, hydrogen peroxide ($H_2O_2$)-induced C6 glial cells were treated with CM at $0.5-2.5{\mu}g/mL$ for measurement of cell viability, ROS production, and protein expression resulting from oxidative stress. RESULTS: The CM extract showed high scavenging activities against DPPH, ${\cdot}OH$, and NO radicals at concentration of $1,000{\mu}g/mL$. Treatment of CM with $H_2O_2$-induced oxidative stress in C6 glial cells significantly increased cell viability, and decreased ROS production. Cyclooxygenase-2 and inducible nitric oxide synthase protein expression was down-regulated in CM-treated groups. In addition, the protein expression level of phospho-p38 mitogen-activated protein kinase (p-p38 MAPK), phospho-c-Jun N-terminal kinase (p-JNK), and phospho-extracellular regulated protein kinases (p-ERK) in $H_2O_2$-induced C6 glial cells was down-regulated upon CM administration. CONCLUSION: CM exhibited radical scavenging activity and protective effect against $H_2O_2$ as indicated by the increased cell viability, decreased ROS production, down-regulation of inflammation-related proteins as well as p-p38, p-JNK, and p-ERK protein levels. Therefore, we suggest that CM could play the protective role from oxidative stress in glial cells.

Anti-oxidative Effects of Taraxaci Herba and Protective Effects on Human HaCaT Keratinocyte (포공영 추출물의 항산화 효과 및 피부 각질세포 보호효과)

  • Kim, Hyung-Woo;Kim, Byung-Joo;Lim, Se-Hyun;Kim, Hyun-Yung;Lee, Sook-Young;Cho, Su-In;Kim, Young-Kyun
    • The Korea Journal of Herbology
    • /
    • v.24 no.3
    • /
    • pp.103-108
    • /
    • 2009
  • Objectives : This study was carried out to investigate anti-oxidative effects of Taraxaci Herba (TH) and protective effects on Human HaCaT keratinocyte. Methods : Anti-oxidative effects were measured by estimating the amount of total phenolics and flavonoids. In addition, DPPH free radical scavenging activities were estimated. Protective effects of TH on HaCaT keratinocytes against oxidative stress induced by hydrogen peroxide were also measured. Results : In our results, treatment with TH did not show cytotoxicity on HaCaT keratinocyte beneath the concentration of 200 $\mu$g/ml. 42.64$\pm$1.90 $\mu$g/ml of total phenolics and 28.09$\pm$1.84 $\mu$g/ml of flavonoids was detected from TH ethanol extract. In addition, DPPH free radical scavenging activities of TH were elevated in dose-dependent manner. In addition, The value of half maximal inhibitory concentration (IC$_{50}$) was 165.5 $\mu$g/ml. Finally, TH showed protective effect against cell death of HaCaT cell induced by hydrogen peroxide significantly. Conclusions : In conclusion, these results suggest that TH may have anti-oxidantic action in human skin and also suggest the possibility as cosmetic material.

Effects of Aucubin Isolated from Eucommia ulmoides on UVB-induced Oxidative Stress in Human Keratinocytes HaCaT

  • Ho, Jin-Nyoung;Cho, Hong-Yon;Lim, Eun-Jeong;Kim, Hye-Kyung
    • Food Science and Biotechnology
    • /
    • v.18 no.2
    • /
    • pp.475-480
    • /
    • 2009
  • Ultraviolet B (UVB) radiation provokes the generation of reactive oxygen species (ROS) in the cells and skin, which induce oxidative stress in the exposed cells, leading to photoaging and cancer. Using the human keratinocytes HaCaT cell line, we investigated the photoprotective effects of aucubin isolated from Eucommia ulmoides. Pretreatment with aucubin markedly suppressed UVB-induced oxidative stress, which manifests as a decrease in intracellular lipid peroxidation, elevation of catalase activity, and reduced glutathione content. In addition, aucubin significantly reduced expression of matrix metalloproteinase-1 (MMP-1) protein (54%) and mRNA. Taken together, these results suggest that aucubin may offer protection against UVB-induced oxidative stress and may be used as a potential agent in prevention of UVB-induced photoaging.

Overexpressed Mitochondrial Thioredoxin Protects PC12 Cells from Hydrogen Peroxide and Serum-deprivation

  • Lee, Yun-Song;Yu, Seung-A
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.7 no.1
    • /
    • pp.33-37
    • /
    • 2003
  • Oxidative damage to mitochondria is a critical mechanism in necrotic or apoptotic cell death induced by many kinds of toxic chemicals. Thioredoxin (Trx) family proteins are known to play protective roles in organisms under oxidative stress through redox reaction by using reducing equivalents of cysteines at a conserved active site, Cys-X-X-Cys. Whereas biological and physiological properties of Trx1 are well characterized, significance of mitochondrial thioredoxin (Trx2) is not well known. Therefore, we addressed physiological role of Trx2 in PC12 cells under oxidative stress. In PC12 cells, transiently overexpressed Trx2 significantly reduced cell death induced by hydrogen peroxide, whereas mutant Trx2, having serine residues instead of two cysteine residues at the active site did not. In addition, stably expressed Trx2 protected PC12 cells from serum deprivation. These results suggest that Trx2 may play defensive roles in PC12 cells by reducing oxidative stress to mitochondria.

Nanoscopic Morphological Changes in Yeast Cell Surfaces Caused by Oxidative Stress: An Atomic Force Microscopic Study

  • Canetta, Elisabetta;Walker, Graeme M.;Adya, Ashok K.
    • Journal of Microbiology and Biotechnology
    • /
    • v.19 no.6
    • /
    • pp.547-555
    • /
    • 2009
  • Nanoscopic changes in the cell surface morphology of the yeasts Saccharomyces cerevisiae (strain NCYC 1681) and Schizosaccharomyces pombe (strain DVPB 1354), due to their exposure to varying concentrations of hydrogen peroxide (oxidative stress), were investigated using an atomic force microscope (AFM). Increasing hydrogen peroxide concentration led to a decrease in cell viabilities and mean cell volumes, and an increase in the surface roughness of the yeasts. In addition, AFM studies revealed that oxidative stress caused cell compression in both S. cerevisiae and Schiz. pombe cells and an increase in the number of aged yeasts. These results confirmed the importance and usefulness of AFM in investigating the morphology of stressed microbial cells at the nanoscale. The results also provided novel information on the relative oxidative stress tolerance of S. cerevisiae and Schizo pombe.

Effect of Soybean Lecithin on the Thermal Oxidation of Tocopherol in Blended Oil (혼합유중(混合油中) Tocopherol의 열산화(熱酸化)에 미치는 대두(大豆) Lecithin의 효과(效果))

  • Chang, Hyun-Ki
    • Journal of the Korean Applied Science and Technology
    • /
    • v.10 no.2
    • /
    • pp.1-6
    • /
    • 1993
  • The blended oil was prepared from cottonseed oil and palm olien. The oxidative stability of blended oil after the addition of natural tocopherol and soybean lecithin during heating was investigated and the effects of lecithin were evaluated. The result obtained were as follows: 1. When the concentration of palm olein in blended oil during heating was increased, the oxidative stability was improved. 2. By both addition of natural tocopherol and soybean lecithin during heating in blended oil, induction period was considerably increased and residual ratio of tocopherol was high. 3. The oxidative stability of potato chips prepared from blended oil was higher in the prsence of lecithin than in the absence of it.