Protective Effects of Lupeol against d‑Galactosamine and Lipopolysaccharide-Induced Fulminant Hepatic Failure in Mice
journal contributionposted on 26.11.2014, 00:00 by So-Jin Kim, Hong-Ik Cho, Seok-Joo Kim, Joon-Sung Kim, Jong-Hwan Kwak, Dong-Ung Lee, Sang Kook Lee, Sun-Mee Lee
This study examined the hepatoprotective effects of lupeol (1, a major active triterpenoid isolated from Adenophora triphylla var. japonica) against d-galactosamine (GalN) and lipopolysaccharide (LPS)-induced fulminant hepatic failure. Mice were orally administered 1 (25, 50, and 100 mg/kg; dissolved in olive oil) 1 h before GalN (800 mg/kg)/LPS (40 μg/kg) treatment. Treatment with GalN/LPS resulted in increased levels of serum alanine aminotransferase, tumor necrosis factor (TNF)-α, and interleukin (IL)-6, as well as increased mortality, all of which were attenuated by treatment with 1. In addition, levels of toll-like receptor (TLR)4, myeloid differentiation primary response gene 88, TIR-domain-containing adapter-inducing interferon-β (TRIF), IL-1 receptor-associated kinase (IRAK)-1, and TNF receptor associated factor 6 protein expression were increased by GalN/LPS. These increases, except TRIF, were attenuated by 1. Interestingly, 1 augmented GalN/LPS-mediated increases in the protein expression of IRAK-M, a negative regulator of TLR signaling. Following GalN/LPS treatment, nuclear translocation of nuclear factor-κB and the levels of TNF-α and IL-6 mRNA expression increased, which were attenuated by 1. Together, the present findings suggest that lupeol (1) ameliorates GalN/LPS-induced liver injury, which may be due to inhibition of IRAK-mediated TLR inflammatory signaling.