Oregano Essential Oil Induces SOD1 and GSH Expression through Nrf2 Activation and Alleviates Hydrogen Peroxide‐Induced Oxidative Damage in IPEC‐J2 Cells

Abstract

Oregano essential oil (OEO) has long been used to improve the health of animals, particularly their intestinal health. The health benefits of OEO are generally attributed to antioxidative actions, but the mechanisms remain unclear. Here, we investigate the antioxidative effects of OEO and their underlying molecular mechanisms in porcine small intestinal epithelial (IPEC-J2) cells. We found that OEO treatment prior to hydrogen peroxide (H2O2) exposure increased cell viability and prevented lactate dehydrogenase (LDH) release into the medium. H2O2-induced reactive oxygen species (ROS) and malondialdehyde (MDA) were remarkably suppressed by OEO. OEO dose-dependently increased mRNA and protein levels of the nuclear factor-erythroid 2-related factor-2 (Nrf2) target genes Cu/Zn-superoxide dismutase (SOD1) and g-glutamylcysteine ligase (GCLC, GLCM), as well as intracellular concentrations of SOD1 and glutathione. OEO also increased intranuclear expression of Nrf2 and the activity of an antioxidant response element reporter plasmid in IPEC-J2 cells. The OEO-induced expression of Nrf2-regulated genes and increased SOD1 and glutathione concentrations in IPEC-J2 cells were reduced by Nrf2 small interfering (si) RNAs, counteracting the protective effects of OEO against oxidative stress in IPEC-J2 cells. Our results suggest that OEO protects against H2O2-induced IPEC-J2 cell damage by inducing Nrf2 and related antioxidant enzymes.

β-TrCP1 Is a Vacillatory Regulator of Wnt Signaling

“…We previously showed—using qRT-PCR, western blot, and luciferase assays—that T-REX-mediated Keap1-specific LDE-modification upregulates AR (and endogenous AR-driven genes) to an extent similar to that from bolus LDE flooding (3–4-fold) (Lin, et al, 2015; Parvez, et al, 2015). Similar fold-AR-upregulation has been reported by us and others for various electrophiles, including HNE (Huang, et al, 2012; Levonen, et al, 2004; Chen, et al, 2009; Zou, et al, 2016; Kachadourian, et al, 2011; Dev, et al, 2015; Trott, et al, 2008). Protein targets beyond Keap1 may be responsible for the pharmacological action of the electrophilic drug tecfidera (dimethylfumarate) (Blewett, et al, 2016).…”

Targeted Isolation of Antioxidant Constituents from Plantago asiatica L. and In Vitro Activity Assay

“…Similar results that 1 mM H 2 O 2 treated for 6 h significantly reduced the cell viability of Caco-2 were observed [15]. Additionally, treatments with 0.8 mM H 2 O 2 for 24 h led to increased release of lactate dehydrogenase (LDH), an indicator of cell membrane injury in IPEC-J2 cells [16]. LDH is a stable intracellular enzyme which can be released into the cell culture medium upon damage of the plasma membrane [17].…”

Effects of phytogenic feed additives on cellular oxidative stress and inflammatory reactions in intestinal porcine epithelial cells1

“…H 2 O 2 is a well-known inducer of ROS and has been used previously to study oxidative stress in IPEC-J2 ( Cai et al, 2013 ). A ROS scavenging effect of some phytochemicals (e.g., polyphenols), including those known from grape seed, licorice, and oregano, has been observed in previous cell-based in vitro studies ( Kim et al, 2012 ; Pinent et al, 2016 ; Zou et al, 2016a ). Also this study confirms a significant induction of ROS after stimulation with H 2 O 2 , and this induction was significantly attenuated by pretreatment of the cells with D-DC, GRS, LIC, and ORE.…”