Protective Mechanisms of Unsaponifiable Matter from Rice Bran Against Tert-Butyl Hydroperoxide-Induced Oxidative Damage in HepG2 Cells

Hyeonmi Ham, Yu Young Lee, Ji Young Park, Choonwoo Lee, Jieun Kwak, In-Hwan Kim, Junsoo Lee

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2 Citations (Scopus)


Rice bran is rich source of phytochemicals, such as phytosterols, tocopherols, tocotrienols, policosanols, γ-oryzanol, triterpene alcohol and other minor compounds. In this study, we investigated the mechanisms underlying the protective effects of unsaponifiable matter from rice bran on tert-butyl hydroperoxide (TBHP)-induced oxidative stress in HepG2 cells. HepG2 cells were pretreated with different concentrations of USM (0-100 μg/mL) for 6 h and oxidative stress was induced by TBHP. The result indicated that pretreatment of HepG2 cells with USM significantly reduced TBHP-induced oxidative damage, as determined by cell cytotoxicity and intracellular reactive oxygen species generations. USM activated nuclear factor-erythroid 2-related factor 2 (Nrf2) nuclear translocation and subsequently enhanced the expression of phase II detoxifying enzymes including heme oxygenase-1, glutamate-cysteine ligase catalytic subunit, and NADPH: quinine oxidoreductase-1. These results suggest that USM-mediated up-regulation of phase II detoxifying enzymes via Nrf2-signaling pathways may provide a pivotal mechanism for its hepatoprotective action.

Original languageEnglish
JournalJournal of Food Biochemistry
Publication statusAccepted/In press - 2016


ASJC Scopus subject areas

  • Cell Biology
  • Pharmacology
  • Biophysics
  • Food Science

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