Polyphenols activate Nrf2 in astrocytes via H2O2, semiquinones, and quinones

Erlank, Hilla; Elmann, Anat; Kohen, Ron; Kanner, Joseph

doi:10.1016/j.freeradbiomed.2011.09.033

Cited by 125 publications

(127 citation statements)

References 60 publications

Supporting

Mentioning

120

Contrasting

Unclassified

Order By: Relevance

“…This suggests that at these concentrations, the polyphenols in these extracts stimulate H 2 O 2 production, resulting in cytotoxicity. In fact, production of H 2 O 2 by polyphenols in culture media has been previously demonstrated (Long et al 2000;Erlank et al 2011). In the same line, high-dose green tea polyphenols was reported to be nephrotoxic in mice (Inoue et al 2011).…”

Section: Discussionmentioning

confidence: 90%

“…This transcription factor has been demonstrated to play an important role in protecting against liver injury (Copple et al 2008) by regulating a battery of antioxidant and cytoprotective genes in response to cellular stress (Mohammadzadeh et al 2012;Bryan et al 2013). The oxidative stress sensing and transcriptional response by Nrf2 has a relatively rapid onset (Zhao et al 2010;Erlank et al 2011). Therefore, we investigated the effect of fraction F25 from both plants on Nrf2 activation status at 12 h before intoxication with H 2 O 2 .…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Antioxidant fractions of Khaya grandifoliola C.DC. and Entada africana Guill. et Perr. induce nuclear translocation of Nrf2 in HC-04 cells

Njayou

Amougou

Tsayem

et al. 2015

Cell Stress and Chaperones

View full text Add to dashboard Cite

The in vitro antioxidant properties, cytoprotective activity, and ability to induce nuclear translocation of nuclear factor E2-related factor-2 (Nrf-2) of five solvent fractions of the methylene chloride/methanol (1:1 v/v) extract of Khaya grandifoliola (Meliaceae) and Entada africana (Fabaceae) were evaluated. Five antioxidant endpoints were used in the antioxidant activity investigation. The total phenolic content of the fractions was assessed as to the Folin-Ciocalteu method and the profile of interesting fractions analyzed by high-performance liquid chromatography (HPLC). The cytoprotective activity of fractions was determined by H2O2-induced oxidative stress in HC-04 cells by measuring lactate dehydrogenase (LDH) leakage into culture medium. HC-04 cells were used to investigate the ability to induce nuclear translocation of Nrf2. For both plants, the methylene chloride/methanol (90/10; v/v) fraction (F10), methylene chloride/methanol (75/25; v/v) (F25), and the methanolic fraction (F100) were found to have the highest total polyphenol content and exhibited high antioxidant activity strongly correlated with total polyphenol content. The cytoprotective activity of fraction F25 from both plants was comparable to that of quercetin (3.40 ± 0.05 μg/mL), inhibiting LDH leakage with a low half inhibition concentration (IC50) of 4.05 ± 0.03 and 3.8 ± 0.02 μg/mL for K. grandifoliola and E. africana, respectively. Lastly, fraction F25 of K. grandifoliola significantly (P < 0.05) induced nuclear Nrf2 translocation by sixfold, whereas that from E. africana and quercetin was only twofold. The results indicate for the first time that fraction F25 of the studied plants is more antioxidant and cytoprotective and induces nuclear translocation of Nrf2 in a human hepatocyte cell line.

show abstract

Section: Discussionmentioning

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Antioxidant fractions of Khaya grandifoliola C.DC. and Entada africana Guill. et Perr. induce nuclear translocation of Nrf2 in HC-04 cells

Njayou

Amougou

Tsayem

et al. 2015

Cell Stress and Chaperones

View full text Add to dashboard Cite

show abstract

“…Although both enzymes are responsible for protecting cells against ROS produced during normal metabolism and after an oxidative insult, these results suggest that alternative pathways could be regulated to cope with the imposed increase of ROS. These alternative pathways could be acting through the antioxidant response element (ARE) and/or the xenobiotic response element (XRE; (Oleaga et al, 2011)) systems with associated induction of induce genes for antioxidant and detoxification enzymes, such as NAD(P)H:quinone oxidoreductase (NQO;1 (Erlank, Elmann, Kohen, & Kanner, 2011)). …”

Section: Discussionmentioning

confidence: 99%

The neuroprotective potential of phenolic-enriched fractions from four Juniperus species found in Portugal

et al. 2012

View full text Add to dashboard Cite

“…[24] Ascorbate, flavonoids, many other polyphenolic compounds, and thiols are unstable in the commonly used cell culture media, undergoing rapid oxidation to generate H 2 O 2 and often other ROS such as superoxide. [1,[45][46][47][60][61][62][63][64][65][66][67] Studies in my laboratory have revealed that many of the apparent effects of these molecules on cells in culture are artifacts due to their oxidation in the cell culture medium. Examples to illustrate this are accumulating in the literature; Table 1 summarizes some of them.…”

Section: 24]mentioning

confidence: 99%

Cell culture, oxidative stress, and antioxidants: Avoiding pitfalls

2014

View full text Add to dashboard Cite

Cell culture is widely used by biochemists and cell/molecular biologists, but the fluctuating (and often elevated) levels of O 2 to which cells in culture are exposed can affect many of their properties. So can the low level of antioxidants found in some cell culture media. Reagents, especially "antioxidants," added to cell culture media can react with the constituents of the media to produce H 2 O 2 and degradation products that can influence cell behavior. Several published papers describing the cellular effects of ascorbate, polyphenols, and carotenoids have, in fact, reported artifacts due to the actions of the degradation products of these "antioxidants." A greater awareness of the potential artifacts in cell culture studies is needed among the free radical/antioxidant community. (Biomed J 2014;37:99-105)

show abstract

Polyphenols activate Nrf2 in astrocytes via H2O2, semiquinones, and quinones

Cited by 125 publications

References 60 publications

Antioxidant fractions of Khaya grandifoliola C.DC. and Entada africana Guill. et Perr. induce nuclear translocation of Nrf2 in HC-04 cells

Antioxidant fractions of Khaya grandifoliola C.DC. and Entada africana Guill. et Perr. induce nuclear translocation of Nrf2 in HC-04 cells

The neuroprotective potential of phenolic-enriched fractions from four Juniperus species found in Portugal

Cell culture, oxidative stress, and antioxidants: Avoiding pitfalls

Contact Info

Product

Resources

About