Study On The Anti-acute Liver Injury And Antidepressant-like Effect And Mechanisms Of ?-mangostin

Mangosteen peel?Garcinia mangostana?is widely used in Thailand,Myanmar,India and other countries as the traditional medicine to treat malaria,diarrhea,inflammatory,leukemia and sepsis.?-MG,as one of the main chemical components of mangosteen,shows several pharmacological activities sunch as anti-tumor,anti-cancer,antibacterial,anti-inflammatory,etc.So,it was proposed that?-MG had anti-acute liver injury and anti-depressant activity combined with the reported biological activity of?-MG,the pathogenesis and pathophysiological characteristics of acute liver injury and depression.This article took?-MG as the research object to explore its preparation process and pharmacological mechanism of anti-depression and Hepatoprotective effect.The main research contents were as follows:1.Study on the mechanism of?-MG to protect acute liver injuryThree acute liver injury models with different mechanisms were established to explore the hepatoprotective activity and mechanism of?-MG.?1?APAP drug-induced acute liver injury model:Excessive APAP was oxidized by cytochrome P450?CYP450?to produce harmful metabolite N-acetylparabenzoimide?NAPQI?.NAPQI combined with GSH to produce thiourea acid or cysteine derivatives to deplete GSH in hepatocytes,which led to oxidative stress,inflammatory reaction and mitochondrial dysfunction,and consequently led to acute liver injury.Mice were continuously treated with?-MG?12.5 and 25 mg/kg?by intragastric administration once daily for 7 days,and injected intraperitoneally with APAP?300 mg/kg?after 1h of?-MG administration on the last day.After APAP exposure for 24 h,the liver and serum were gathered to evaluate the hepatotoxicity.Serum was used to detect the levels of aspartate aminotransferase?AST?,alanine aminotransferase?ALT?,tumor necrosis factor-??TNF-??and interleukin-6?IL-6?,Interleukin-1??IL-1??.Liver tissue was used to detect the contents of glutathione?GSH?,superoxide dismutase?SOD?,catalase?CAT?,and malondialdehyde?MDA?.After that,liver tissues were measured by H&E,Western blot and RT-PCR to analyze the mechanism of hepatoprotective effect of?-MG on drug-induced liver injury.The results showed that?-MG effectively decreased the levels of serum ALT,AST,TNF-?,IL-1?,IL-6 levels;increased GSH,SOD and CAT vitality,and decreased the content of hepatic malondialdehyde?MDA?.Liver histopathological observation provided further evidence that?-MG pretreatment significantly inhibited APAP-induced hepatocellular necrosis,infiltration of inflammatory cell and hyperemia.According to the analysis of western-blot and RT-PCR detection,?-MG pretreatment validly inhibited the phosphorylation of ERK,JNK and p38 MAPK induced by APAP,the phosphorylation of I?B?and the translocation of NF-?Bp65were also attenuated by?-MG.At the same time,?-MG reduced the hepatic mRNA levels of TNF-?,IL-6 and IL-1?.In conclusion,?-MG has obvious hepatoprotective effect on acute liver injury induced by APAP,which prevents APAP-induced acute liver injury by inhibiting NF-?B and MAPK signaling pathways,and the mechanism is related to its strong anti-oxidation and anti-inflammatory activity.?2?LPS/D-GalN-induced fulminant liver injury model:LPS directly activated TLR4 on the surface of hepatic stellate cells,HSCs,which resulted in the release of inflammatory cytokines and hepatocyte apoptosis and necrosis.D-GalN consumed uridine triphosphatase?UTP?,thus inhibiting the synthesis of related RNA and protein in the liver.The combination of the two caused liver inflammation and diffuse necrosis of hepatocytes,leading to fulminant acute liver injury.Mice were treated with?-MG?12.5,25 mg/kg,i.g.?once daily for 7 days prior to challenge experiment.On the last day,LPS?50?g/kg?combined with D-GalN?800 mg/kg?was intraperitoneally injected in mice 1h after?-MG administration.For further laboratory analysis,mice samples of serum and liver were obtained 8 h after LPS/D-GalN injection.The related indexes of serum and liver tissue were determined according to the kit's instructions.After that,liver tissues were measured by H&E,Western blot and RT-PCR to analyze the mechanism of hepatoprotective effect of?-MG on LPS/D-GalN-induced fulminant liver injury.The results showed that?-MG could reduce serum ALT,AST,TNF-?,IL-1?,IL-6 levels;increased the content of GSH,SOD,CAT,and decreased the content of MDA.?-MG also attenuated LPS/D-GalN-induced liver pathological injury.The results of Western-blot indicated that?-MG inhibited LPS/D-GalN-induced toll-like receptor 4?TLR4?expression and NF-?B activation.Besides,?-MG up-regulated the expressions of Nrf2 and heme oxygenase-1?HO-1?.In conclusion,the results indicated that?-MG protected against LPS/D-GalN-induced liver failure by activating Nrf2 to induce antioxidant defense and inhibiting TLR4 signaling pathway to induce anti-inflammatory effect.?3?CCl4-induced chemical acute liver injury model:CCl4 was metabolized by cytochrome P450?CYP P450?to generate ROS in the hepatocyte endoplasmic reticulum,which damaged DNA,biofilmand,triggered lipid peroxidation damage and induced changes in gene expression of hepatocytes.Liver tissue cells also secreted a large number of inflammatory factors,leading to inflammation and ultimately to be acute liver injury.Mice were continuously treated with?-MG?12.5 and 25 mg/kg?by intragastric administration once daily for 7 days,and injected intraperitoneally with 0.2%CCl₄ after 1h of?-MG administration on the last day.After 0.2%CCl₄ exposure for 24 h,the liver and serum were gathered to evaluate the hepatotoxicity.The related indexes of serum and liver tissue were determined according to the kit's instructions.After that,liver tissues were measured by H&E,Western blot and RT-PCR to analyze the mechanism of hepatoprotective effect of?-MG on CCl₄-induced chemical liver injury.The results showed that the?-MG administration group did not decreased the levels of AST and ALT compared with the model group,indicating that?-MG could not alleviate acute liver injury induced by CCl₄.2.Study on the mechanism of antidepressant activity of?-MGIn this study,the classical behavioral despair model Tail suspension test?TST?and Forced swim test?FST?were used to explore antidepressant activity of?-MG and the effective dose and sub-effective dose were screened.In order to exclude the false positive effect in the behavioral despair test,the effect of?-MG on the autonomic activity of mice was also tested.Next,the co-administration experiments were conducted to determine the effects of blockers and agonists on the antidepressant activity of?-MG,and the effects of central neurotransmitters on the antidepressant activity of?-MG.The results showed that?-MG has strong antidepressant activity.The effective dose of?-MG was 5 mg/kg,and the sub-effective dose was 1 mg/kg.For?-MG,the immobility time of mice in the TST was more sensitive than that in the FST,illustrating that the TST was more favorable than the FST for screening antidepressant activity for?-MG.Therefore,we choose TST as a model for follow-up experiments.The results of co-administration showed that the combination of?-MG?1 mg/kg?and the antidepressants fluoxetine,tinaeptine,and reboxetine significantly reduced the immobility time and exhibited a synergistic effect.The results of combination blockers and agonists showed that pretreatment with bicuculline?a competitive GABA antagonist?,p-chlorophenylalanine?an inhibitor of 5-HT synthesis?and haloperidol?a non-selective D₂ receptor antagonist?significantly reversed the antidepressant-like effects of?-MG?5 mg/kg?and altered the corresponding central neurotransmitter levels in the brain,suggesting that the antidepressant-like effects of?-MG might be mediated by GABAergic,serotoninergic and dopaminergic systems.