Effect And Mechanism Of Sulforaphane On Hepatic Ischemia Reperfusion Injury In Rats

Objective In order to combat with various damage of environment, cells have evolved a series of complex defensive mechanisms, the most important of which is regulated by the transcription factor NF‐E2related factor2（Nrf2）. Sulforaphane, as an agonist of Nrf2, is extracted from cruciferous vegetable. So far, numerous studies have proven that sulforaphane can produce anti‐inflammation and anti‐oxidant effect though activation of Nrf2, thus it plays a significant role on the protective effect of multiple organs such as the lungs, kidneys, heart and nervous system. But different dose of sulforaphane（SFN） effects on hepatic ischemia reperfusion injury has not been reported. This study is purpose to explore the influence of different dose of sulforaphane on hepatic warm ischemia reperfusion injury（IRI） and the possible mechanism.Methods fifty Male Sprague‐Dawley rats（weighing200to220g）were used in these experiments, the rat model of hepatic ischemia reperfusion injury was set up by blocking blood flow to the left, middle and the left lateral lobe of liver with scatheless artery clamp for60min and then removing the artery,following with reperfusion for6h. Rats were randomly divided into five groups and each containing ten rats. Ⅰ group: sham group, hepatic artery and portal vein just were separated without clamped. Ⅱ group: model group, hepatic ischemia reperfusion injury model was established using the above methods. Ⅲ, Ⅳ, Ⅴ group: SFN_1mg/kg、SFN_3mg/kg or SFN_5mg/kg, intraperitoneal injection of1mg/kg、3mg/kg or5mg/kg sulforaphane1h before anaesthesia, and the rest steps were the same as the model group. The rats were sacrificed by exsanguination at the end of6h reperfusion; liver tissue and arterial blood were collected. The measured indexes include: the levels of AST, ALT in the blood plasma; the levels of SOD, MDA, MPO in liver tissue homogenate; liver tissue ultrastructure changes; the expression of HO‐1in the liver was determined by immunohistochemical method. The statistical significance of differences between groups was analyzed using the oneway analysis of variance （ANOVA） and methods of LSD with the SPSS13.0for windows XP statistical software package. Statistical differences were considered significant if the P value was <0.05.Result Comparison of serum AST、ALT levels: Compared with Ⅰ group, the serum AST、ALT levels of group Ⅱ、Ⅲ、Ⅳ、Ⅴ were remarkable higher （P<0.05）; Compared with Ⅱ group, the serum AST、ALT levels of group Ⅲ、Ⅳ、Ⅴ were significant lower（P<0.05）; Compared with Ⅲ group, the serum AST、ALT levels of group Ⅳ、Ⅴ were lower（P<0.05）; Compared with Ⅴgroup, the serum AST、ALT levels of groupⅤ were lower（P<0.05）. Comparison of liver tissue homogenate SOD、MDA、MPO levels: Compared with Ⅰ group, group Ⅱ showed a marked rise in the MDA、MPO levels of liver tissue homogenate （P<0.05）, and a notable drop in SOD levels of liver tissue homogenate （P<0.05）; Compared with Ⅱ group, group Ⅲ、Ⅳ、Ⅴ showed an apparent rise in the MDA、MPO levels of liver tissue homogenate （P<0.05）, and a clear drop in SOD levels of liver tissue homogenate （P<0.05）; Compared with Ⅲ group, group Ⅳ、Ⅴ showed a rise in the MDA、MPO levels of liver tissue homogenate （P<0.05）, and a drop in SOD levels of liver tissue homogenate （P<0.05）; Compared with Ⅳ group, group Ⅴ showed a rise in the MDA、MPO levels of liver tissue homogenate （P<0.05）, and a drop in SOD levels of liver tissue homogenate （P<0.05）. Liver tissue ultrastructure changes: sham group, normal appearance of mitochondrion, rough endoplasmic reticulum and nucleus structure. compared with sham group, the occluded liver tissue from the I/R group was markedly damaged, with mitochondrion swollen, vacuolar degeneration and, mitochondrial crista destruction, marked decrease of rough endoplasmic reticulum and nucleus structure destruction under the electron microscope. Pretreatment of rats with 1,3or5mg/kg sulforaphane resulted in a significant amelioration of hepatic injury. Compared withⅠ group, the expression of HO‐1of group Ⅱ showed no obvious difference（P>0.05）; Compared with Ⅱ group, the expression of HO‐1of group Ⅲ、Ⅳ and Ⅴwere significantly increased（P<0.05）. Compared with Ⅲ group, Ⅳ and Ⅴ group displayed a marked rise in the expression of HO‐1（P<0.05）. Compared with Ⅳ group, the expression of HO‐1of group Ⅴ was significantly increased（P<0.05）.Conclusion The studies showed that pretreatment with sulforaphane can exert protection against hepatic ischemic reperfusion injury in the rat and the protection effect displayed a does dependent. The mechanism may be associated with activation of Nrf2, up regulation the expression of HO‐1,repression of inflammatory factors and attenuation of oxidative stress reaction.