Effects of Oxidative Stress Caused by <i>tert</i>-Butylhydroquinone on Cytotoxicity in MDCK Cells

Abstract

ABSTRACT. Antioxidant and oxidative stress effects of prooxidants are generally dose-dependent, and these effects depend on the prooxidant species and cell type. However, the cellular response to oxidant challenge is a complicated interplay of events involving cellular expression of phase II detoxification enzymes and cellular metal metabolism. This study demonstrates the effect of tertbutylhydroquinone (t-BHQ)-induced oxidative stress on MDCK cells. Cell toxicity tests were carried out using the crystal violet (CV) assay with the following prooxidants: t-BHQ, diethyl maleate (DEM), hydrogen peroxide (H 2 O 2 ), diquat (DQ) and β-naphthoflavone (β-NF). Except for β-NF, these prooxidants showed dose-dependent cytotoxicity besides the most potent t-BHQ cytotoxicity. Only t-BHQ and DEM caused significant time-dependent expression of ferritin protein as an antioxidant, which segregates Fe 2+ , causing the Fenton reaction. t-BHQ and DEM increased formation of lipid peroxidation, but DQ showed a tendency to decrease lipid peroxidation levels. In XTT assay, even when substantial cell death was observed in the CV assay, t-BHQ appeared to increase cell viability by enhancing XTT reduction, likely through the production of NADPH. Although curcumin, which induces cytoprotective phase II enzymes and chelates metal irons, decreased cell viability, it inhibited t-BHQ cytotoxicity. These results indicate that t-BHQ exhibits strong cytotoxicity against MDCK cells, an effect mitigated by curcumin, and that t-BHQ-induced oxidative stress activates the pentose phosphate pathway.

Antioxidant Pre-Treatment Reduces the Toxic Effects of Oxalate on Renal Epithelial Cells in a Cell Culture Model of Urolithiasis

“…In LLC-PK1 cell line, cell survival was smaller for the same concentrations of l -arginine in comparison to MDCK I and II cell lines with peak of the effects shifted toward smaller concentrations of the antioxidant. These results are comparable to previous work done on kidney epithelial cell lines, which had shown dose dependence of antioxidant effect in reducing oxidative stress [ 34 , 35 ]. This shows that further studies are needed to determine what effect it would have on human kidney epithelial cells.…”

Abnormal Oxidative Stress Responses in Fibroblasts from Preeclampsia Infants

“…Induction of oxidative stress was performed according to the method of Shibuya et al [29]. The UC fibroblasts were passaged into wells (area 0.32 cm 2 ) of a 96 well plate at a density of 1.0×10 4 /cm 2 for 24 h under 4% O 2 in 0.1 ml of medium containing DEM (Sigma, #W505005) at concentrations ranging from 0.1 mM to 1.0 mM.…”

“…The UC fibroblasts were passaged into wells (area 0.32 cm 2 ) of a 96 well plate at a density of 1.0×10 4 /cm 2 for 24 h under 4% O 2 in 0.1 ml of medium containing DEM (Sigma, #W505005) at concentrations ranging from 0.1 mM to 1.0 mM. tBHQ (Sigma #112941) was tested similarly over a concentration range of 0.02 to 0.2 mM [29]. To terminate the experiment, cells were washed 3x with PBS, fixed with buffered 10% formalin solution (pH 7.2), and then stained with 0.1% crystal violet in H 2 O.…”

Nrf2-ARE-Dependent Alterations in Zinc Transporter mRNA Expression in HepG2 Cells

“…To address this, we have investigated Nrf2-ARE signaling-dependent alterations in zinc transporter mRNA levels in HepG2 cells, using tert -butylhydroquinone ( t -BHQ) as an activator of the Nrf2-ARE signaling pathway. Although t -BHQ is known as a pro-oxidant [13,14], it can induce phase II detoxification enzymes, such as glutathione- S -transferase, via the Nrf2-ARE signal transduction pathway [13,15–17]. As such, t -BHQ can serve as a useful compound to improve our understanding of the cellular effects through the Nrf2-ARE signal transduction pathway.…”