The mechanism of hepatoprotective effect of sesquiterpene rich fraction from Cichorum glandulosum Boiss. et Huet on immune reaction-induced liver injury in mice

Abstract

Ethnopharmacological relevanceCichorum glandulosum Boiss. et Huet is a traditional Uygur herbal medicine that has been used as a cholagogic and diuretic agent to improve liver function. However, the mechanism is not known for the liver-protective function. We investigated the antioxidant effects of plant extraction (CGE60) in vitro and in vivo, and find the mechanism of liver protection in Bacille Calmette-Guerin vaccine (BCG)+Lipopolysaccharides (LPS) induced liver injury in mice. Materials and methodsCGE60 was made, and the antioxidant activity was investigated by comparing the ability of scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH), and 2,2-azinobis(3-ehtylbenzothiazolin-6-sulfnicAcid) diammonium salt (ABTS) free radicals in vitro. Then, CGE60 was administrated in mice of liver damage model which was induced in mice using the BCG+LPS protocol. The CGE 60 extract was tested at three dosages: 50mg/kg, 100mg/kg, and 200mg/kg. Product of lipid peroxidation (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX,), nitric oxide (NO), nitric oxide synthetase (NOS), hydroxyproline and alkaline phosphatase (ALP) contents were evaluated in liver to determine the CGE60 activity in the hepatic injury model. Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and transforming growth factor-β (TGF-β) proteins were determined in the liver tissues using ELSIA. The signaling activities were evaluated in Western blot. ResultsCGE60 exhibited strong antioxidant ability in vitro. With oral administration, CGE60 significantly increased the activity of CAT, SOD, GSH-PX, and decreased the level of NO, NO synthase, hydroxyproline, ALP and lipid peroxidation liver of in the BDG+ LPS model. CGE60 attenuated hepatic inflammation via down- regulation of TNF-α, IL-6 and TGF-β. CGE60 blocked protein expression of cytochrome P450 2E1 (CYP2E1), nuclear factor kappa-B (NF-κB), phosphorylation of extracellular signal-regulated kinase (p-ERK1/2), and cyclooxygenase-2 (COX-2),but activated the expression of p-P38 MAPK. ConclusionThis study suggests that CGE60 possesses antioxidant activity and this activity associates with hepatoprotective effect in the mice of BCG +LPS model, and the mechanisms underlying these effects may involve antioxidant actions and anti-inflammation activities.