Protective Effects Of Lycium Barbarum Polysaccharides On CCl₄-induced Liver Injury In Jian Carp?Cyprinuscarpio?

Liver is prone to xenobiotic-induced injury because of its central role in xenobiotics metabolism,its portal location within the circulation,and its anatomic and physiologic structure.Many compounds can cause liver damage through their metabolic conversion to highly reactive substances and the generation of free radicals.Recently in China,a fish liver disease called "fish hepatobiliary syndrome",with the symptoms of color change and enlargements of liver and gall bladder,has been frequently reported and caused dramatic losses in many cultured species.There have been no effective treatments for the fish hepatobiliary syndrome,hence the search for plant-based remedies is of considerable interest to researchers and aquatic medicine producers.The protective effects of Lycium barbarum polysaccharides?LBP?against carbon tetrachloride-induced hepatotoxicity in common carp were investigated in vitro?precision-cut liver slices?and in vivo.The main research contents and results were as followed:1.Preparation and culture of slices:slices with different thicknesses?200?m,300 ?m,400 ?m,500 ?m?were cultured under different pH?6.8,7.0 and 7.2?conditions for 0,8,16,24,48 h,then the culture supernatants and slices were collected.GPT,GOT and LDH in the culture supernatants and ATP in the liver slice homogenates were measured using kits.The results showed that the slices with 300 ?m in thickness under pH 7 were viable for 16 hours.2.Slices were cultured with different concentrations of CCl₄?0,4,8,12,16,32 mM?.After 4 hours,the slices and supernatant were collected to measure ATP,GOT,GPT,LDH,SOD and MDA.Western blotting was used to explore the effect of CCl₄ on the expressions of p65 and c-Rel.The result showed that slices treated with 16,32 mM CCl₄ Chad higher activities in GOT,GPT,LDH,MDA and c-Rel,p65,compared with control group.Slices treated with 4,8,12 mM CCl₄ showed little difference with control group in ATP content,however the varied cytosolic enzymes were observed,therefore,CCl₄ at the concentration of 12 mM was selected as the inducer.3.Protective effects of Lycium babarum polysaccharides against liver injury:In vitro,LBP?0.1,0.3 and 0.6 mg/ml?was added to PCLS culture system before?pre-treatment?,after?post-treatment?and both before and after?pre-and post-treatment?the exposure of PCLS to 12 mM CCl₄.The supernatants and PCLS were collected for biochemical analyses.In vivo,fish were fed diets containing 0.1,0.5 and 1%LBP for 60 d before an intraperi-toneal injection of 30%CCl₄ in olive oil at a volume of 0.05 ml/10 g body weight.At 72 h post injection,blood and liver samples were taken for biochemical analyses.Results showed that in vitro,LBP inhibited the elevations of the marker enzymes?GOT,GPT,LDH and AKP?and MDA induced by CCl₄ in all LBP treatments,it also enhanced the suppressed antioxidant enzymes?SOD,CAT,GSH-Px,GST?,T-AOC and GSH in the pre-treatment and pre-and post-treatment.Furthermore,LBP inhibited the expression of CYP1 A,CYP3A,CYP2E1 and the prote:in expression of c-Rel and p65.In vivo,LBP at 0.5 and 1%reduced the levels of GOT,GPT and LDH significantly,and the decreases of the antioxidant enzymes and the increase of MDA in the liver tissue were inhibited markedly.Overall results proved the hepatoprotective and antioxidant effects of LBP and supported the use of LBP as a hepatoprotective agent in fish.