title: Hepatoprotective effects of rice-derived peptides against acetaminophen-induced damage in mice.
abstract: Glutathione, the most abundant intracellular antioxidant, protects cells against reactive oxygen species induced oxidative stress and regulates intracellular redox status. We found that rice peptides increased intracellular glutathione levels in human hepatoblastoma HepG2 cells. Acetaminophen is a commonly used analgesic. However, an overdose of acetaminophen causes severe hepatotoxicity via depletion of hepatic glutathione. Here, we investigated the protective effects of rice peptides on acetaminophen-induced hepatotoxicity in mice. ICR mice were orally administered rice peptides (0, 100 or 500 mg/kg) for seven days, followed by the induction of hepatotoxicity via intraperitoneal injection of acetaminophen (700 mg/kg). Pretreatment with rice peptides significantly prevented increases in serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase levels and protected against hepatic glutathione depletion. The expression of γ-glutamylcysteine synthetase, a key regulatory enzyme in the synthesis of glutathione, was decreased by treatment with acetaminophen, albeit rice peptides treatment recovered its expression compared to that achieved treatment with acetaminophen. In addition, histopathological evaluation of the livers also revealed that rice peptides prevented acetaminophen-induced centrilobular necrosis. These results suggest that rice peptides increased intracellular glutathione levels and could protect against acetaminophen-induced hepatotoxicity in mice.
authors.affiliation: School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-Ku, Okayama 703-8516, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Kawakami
authors.affiliation: School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-Ku, Okayama 703-8516, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Moritani
authors.affiliation: Okayama Prefectural Technology Canter for Agriculture, Forestry and Fisheries, Research Institute for Biological Sciences (RIBS), Okayama, 7549-1 Kibichuo-cho, Kaga-gun, Okayama 716-1241, Japan.
authors.forename: Misugi
authors.initials: M
authors.lastname: Uraji
authors.affiliation: SATAKE Corporation, 2-30 Saijo Nishihonmachi, Higashi-Hiroshima-shi, Hiroshima 739-8602, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Fujita
authors.affiliation: SATAKE Corporation, 2-30 Saijo Nishihonmachi, Higashi-Hiroshima-shi, Hiroshima 739-8602, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kawakami
authors.affiliation: Okayama Prefectural Technology Canter for Agriculture, Forestry and Fisheries, Research Institute for Biological Sciences (RIBS), Okayama, 7549-1 Kibichuo-cho, Kaga-gun, Okayama 716-1241, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hatanaka
authors.affiliation: School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-Ku, Okayama 703-8516, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Suzaki
authors.affiliation: School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-Ku, Okayama 703-8516, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Tsuboi
keywords: acetaminophen; glutathione; liver injury; rice-derived peptide