Protective effect of liriodendrin against liver ischaemia/reperfusion injury in mice via modulating oxidative stress, inflammation and nuclear factor kappa B/toll-like receptor 4 pathway

BACKGROUND

The aim of the present study was to investigate the protective effect and mechanism of liriodendrin (LDN) is a lignan diglucoside in hepatic ischaemia/ /reperfusion (I/R) injury.

MATERIALS AND METHODS

The liver I/R was established in male C57BL/6 mice. The effect of LDN is initially investigated on hepatic I/R injury via estimating histopathology of liver. The level of metabolic enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) was studied along with apoptosis of mouse hepatocytes via TUNEL and flow cytometry analysis. The effect of LDN was investigated on oxidative stress biomarkers (glutathione [GSH] content, malondialdehyde [MDA] and superoxide dismutase [SOD] activities) and pro-inflammatory cytokines (tumour necrosis factor alpha [TNF-α], interleukin [IL]-1β and IL-6). Western blot study was also conducted to elucidate the effect of LDN on toll-like receptor 4/nuclear factor kappa B (TLR4/NF-kB).

RESULTS

Liriodendrin alleviates liver I/R injury, as manifested by decreased plasma ALT, AST and ALP with improvement in liver necrotic area. LDN also reduces apoptosis of mouse hepatocytes with reduction of oxidative stress and generation of pro-inflammatory cytokines. It significantly reduces the expression of TLR4 and NF-kB.

CONCLUSIONS

The study demonstrated that LDN reduces liver injury and prevented apoptosis of hepatocytes following I/R injury. In addition, LDN also reduces oxidative stress, inflammation, and TLR4/NF-kB in I/R injured mice.

Preconditioning of umbilical cord-derived mesenchymal stem cells by rapamycin increases cell migration and ameliorates liver ischaemia/reperfusion injury in mice via the CXCR4/CXCL12 axis

Objectives

Transfusion of umbilical cord‐derived mesenchymal stem cells (UC‐MSCs) is a novel strategy for treatment of various liver diseases. However, the therapeutic effect of UC‐MSCs is limited because only a few UC‐MSCs migrate towards the damaged regions. In this study, we observed the effects of autophagy on the migration of UC‐MSCs in vitro and in a model of liver ischaemia/reperfusion (I/R) injury.

Materials and Methods

We investigated the effects of autophagy on the status of the cell, release of anti‐inflammatory factors and migration of UC‐MSCs in vitro. The therapeutic effects and in vivo migration of rapamycin‐preconditioned UC‐MSCs were observed in a C57/B6 mouse model of liver I/R injury.

Results

Induction of autophagy by rapamycin enhanced the ability of UC‐MSCs to migrate and release anti‐inflammatory cytokines as well as increased expression of CXCR4 without affecting cell viability. Inhibition of CXCR4 activation markedly decreased migration of these cells. In a mouse model of liver I/R injury, we found significantly upregulated expression of CXCR12 in the damaged liver. More rapamycin‐preconditioned UC‐MSCs migrated towards the ischaemic regions than 3‐methyladenine‐preconditioned or non‐preconditioned UC‐MSCs, leading to improvement in hepatic performance, pathological changes and levels of inflammatory cytokines. These effects were abolished by AMD3100.

Conclusions

Preconditioning of UC‐MSCs by rapamycin afforded increased protection against liver I/R injury by enhancing immunosuppression and strengthening the homing and migratory capacity of these cells via the CXCR4/CXCL12 axis.

Intraperitoneal administration of apigenin in liver ischemia/reperfusion injury protective effects

BACKGROUND/AIMS

Hepatic injury caused by ischemia/reperfusion (I/R) is a clinical problem associated with major liver surgery. Among other flavonoids, apigenin has shown a promising effect on I/R cases. In this study, we have investigated the effects of apigenin after liver I/R injury in rats.

MATERIALS AND METHODS

Forty eight rats were randomized into the following eight groups: (1) Control-sham group: rats subjected to the surgical procedure, except for liver I/R; (2) DMSO group: rats subjected to surgery, except for liver I/R given the apigenin solvent dimethyl-sulfoxide intraperitoneally; (3) C60 group; (4) C120 group; (5) C240 group: rats underwent liver ischemia for 45 min followed by reperfusion for 60 min, 120 min, and 240 min; (6) AP60 group; (7) AP120 group; (8) AP240 group: rats underwent liver ischemia for 45 min, and then given apigenin (5 mg) intraperitoneally followed by reperfusion for 60 min, 120 min, and 240 min. Reverse transcription polymerase chain reaction was performed on liver tissues to measure BCL-2/BAX expression, enzyme-linked immunosorbent assay to measure M30/M65 and ICAM-1. Immunohistochemistry was used to identify M30 biomarker in liver tissues.

STATISTICAL ANALYSIS

Quantitative variables were tested by Kolmogorov-Smirnov test, repeated measures analysis of variance/Friedman test. Gene levels were assessed by Student's t-test/Mann-Whitney U-test.

RESULTS

BCL-2 levels were significantly higher in I/R apigenin groups than in I/R control groups. BAX levels were lower in the AP240 group than in C240 group. Prolongation of reperfusion resulted in increased activation of M30. ICAM-1 levels were lower in the AP240 group than in C240 group.

CONCLUSIONS

Apigenin seems to inhibit the process of apoptosis and ameliorate the hepatic I/R injury.