ABSTRACT
The purpose of this study was to investigate the protective roles and mechanisms of Dendrobium officinale polysaccharides (DOPS) on secondary liver injury in acute colitis. Firstly, the mice model of secondary liver injury in acute colitis was induced by 4% Dextran sodium sulfate (DSS). Inflammatory cell model was established by LPS-stimulated RAW264.7 cells. Then, the protective roles of DOPS were evaluated by both in vivo and in vitro experiment. The results showed that DOPS attenuated DSS-induced hepatic pathological damage, liver parameters, infiltration of macrophages, cytokines levels, MDA level and increased the antioxidant enzymes activities. In vitro, DOPS markedly inhibited inflammatory cytokines production and increased antioxidant enzymes activities. Finally, its molecular mechanisms were also observed. The results indicated that DOPS could down-regulated TNF-α signaling pathway and activated Nrf-2 signaling pathway in vivo and in vitro. These results suggested that DOPS may be an effective therapeutic reagent to attenuate secondary liver injury in acute colitis.
Subject(s)
Colitis/drug therapy , Dendrobium/chemistry , Liver/injuries , Polysaccharides/therapeutic use , Protective Agents/therapeutic use , Acute Disease , Alanine Transaminase/blood , Animals , Antioxidants/pharmacology , Antioxidants/therapeutic use , Aspartate Aminotransferases/blood , Cell Survival/drug effects , Colitis/blood , Colitis/chemically induced , Colitis/pathology , Cytokines/blood , Cytokines/genetics , Dextran Sulfate , Glutathione Peroxidase/metabolism , Inflammation Mediators/metabolism , Lipids/blood , Lipopolysaccharides/biosynthesis , Liver/drug effects , Liver/pathology , Macrophages/drug effects , Macrophages/pathology , Male , Malondialdehyde/metabolism , Mice , Mice, Inbred BALB C , Oxidative Stress , Polysaccharides/pharmacology , Protective Agents/pharmacology , RAW 264.7 Cells , RNA, Messenger/genetics , RNA, Messenger/metabolism , Signal Transduction , Superoxide Dismutase/metabolismABSTRACT
BACKGROUND AIMS: Assessing mesenchymal stromal cells (MSCs) after grafting is essential for understanding their migration and differentiation processes. The present study sought to evaluate via cellular magnetic resonance imaging (MRI) if transplantation route may have an effect on MSCs engrafting to fibrotic liver of rats. METHODS: Rat MSCs were prepared, labeled with superparamagnetic iron oxide and scanned with MRI. Labeled MSCs were transplanted via the portal vein or vena caudalis to rats with hepatic fibrosis. MRI was performed in vitro before and after transplantation. Histologic examination was performed. MRI scan and imaging parameter optimization in vitro and migration under in vivo conditions were demonstrated. RESULTS: Strong MRI susceptibility effects could be found on gradient echo-weighted, or T2∗-weighted, imaging sequences from 24 h after labeling to passage 4 of labeled MSCs in vitro. In vivo, MRI findings of the portal vein group indicated lower signal in liver on single shot fast spin echo-weighted, or T2-weighted, imaging and T2∗-weighted imaging sequences. The low liver MRI signal increased gradually from 0-3 h and decreased gradually from 3 h to 14 days post-transplantation. The distribution pattern of labeled MSCs in liver histologic sections was identical to that of MRI signal. It was difficult to find MSCs in tissues near the portal area on day 14 after transplantation; labeled MSCs appeared in fibrous tuberculum at the edge of the liver. No MRI signal change and a positive histologic examination were observed in the vena caudalis group. CONCLUSIONS: The portal vein route seemed to be more beneficial than the vena caudalis on MSC migration to fibrotic liver of rats via MRI.
