Anti-fatigue Activity And Protective Effects Of MRJPs On Carbon Tetrachloride-induced Acute Liver Injuries In Mice

Objective:Major Royal Jelly Proteins(MRJPs),a principal water-soluble component of royal jelly(RJ),is considered to be the main substance involved in the physiological and biological actions of RJ.This study is aimed at researching the anti-fatigue effect of MRJPs in mice and the physiological and molecular mechanisms underlying this effect.And in this study,the hepatoprotective effect of MRJPs on carbon tetrachloride(CCl4)induced hepatic damages in C57 BL mice liver was investigated.Methods:(1)Extraction of MRJPs.Fresh royal jelly was dissolved in PBS,by extraction,centrifugation,dialysis,drying the resulting MRJPs powder.The presence of proteins in RJ fractions was analyzed by SDS-PLGA.(2)Briefly,male mice were divided into five groups randomly,that is,Control group,RJ group,and three of the groups were administered different doses of MRJPs.Four weeks after MRJPs was administrated gavage to mice at three different doses,the anti-fatigue effect of MRJPs was evaluated by the weight-loaded swimming test and biochemical parameters related to fatigue,such as serum urea nitrogen(SUN),lactic dehydrogenase(LDH),blood lactic acid(LA)and hepatic and muscle glycogen.Otherwise,we carry out the hypoxia tolerance experiment and acute cerebral ischemia hypoxia experiment.(3)Mice were randomly divided into six groups including negative control(N),positive control(P,CCl4 treated control group),Drug control(D),MRJPs(H,480mg/kg)plus CCl4 treated group,MRJPs(M,320 mg/kg)plus CCl4 treated group and MRJPs(L,160 mg/kg)plus CCl4 treated group,respectively.The mice were pre-treated orally with MRJPs(480,320 or 160 mg/kg)once daily for 28 days before CCl4(10ml/kg of 0.2% CCl4 solution in olive oil)injection.The hepatoprotective effect of MRJPs was evaluated by the biochemical parameters related to hepatic damages,such as ALT,AST,SOD,MDA and TNF-α.Results:(1)The results showed that compared with the negative control group,the weight loading swimming times of the low-,medium-and high-dose groups were prolonged.Experimental investigation showed that the hepatic and muscle glycogen,lactate dehydrogenase concentration levels of the treatment groups were higher than those of the control group(P<0.05).The survival time of all test groups were longer than the control group in the survival experiment of normobaric hypoxia test and in acute cerebral ischemia hypoxia experiment,respectively.(2)The results showed that MRJPs decreased serum ALT and AST activities compared with positive group.In addition,MRJPs remarkably increased the levels of SOD and decreased MDA in liver.Histopathological test results also show that MRJPs can effectively inhibit the acute liver injury induced by CCl4.Further investigation demonstratedthat MRJPs decreased the levels of TNF-αin the serum,but markedly increased the gene expression of TNF-αin liver.Conclusion:(1)The results of the experimental investigation indicated that MRJPs exerts an anti-fatigue effect on mice.(2)MRJPs prevent carbon tetrachloride-induced acute liver injury in mice through preventing CCl4-induced reduction of anti-oxidant capacity in mouse livers to relieve inflammatory response and hepatocyte apoptosis.