Study On Pharmacological Activity And Mechanism Of An Novel FXR Agonist LZ-007

Nonalcoholic fatty liver disease(NAFLD)is a liver pathology manifestation of metabolic syndrome,including fatty liver disease,nonalcoholic steatohepatitis(NASH),and its progression to fibrosis,cirrhosis,and liver cancer.The incidence of NAFLD is on the rise and has become a global health threat.Therefore,it is urgent to develop safe and effective anti-NAFLD drugs for clinical treatment.Farnesoid X receptor(FXR)is a member of the nuclear receptor superfamily,which is mainly distributed in the liver and intestinal tissues.In addition,activating hepatic FXR can decrease liver inflammation,fibrosis,regeneration,and cancer by modifying the homeostasis of bile acids,sugars,and lipids.Ultimately,activation of FXR can delay the development of hepatic metabolic lesions.Overall,FXR agonists have a very strong resistance to fatty liver disease.Meanwhile,it has become a hot spot for drug research for NAFLD.Based on summarizing the structurally active relationship of FXR agonists,we mainly used the non-steroidal FXR agonist GW4064 as the lead compound.Then,we reconstructed the skeleton and carboxyl part of GW4064 respectively.Through our efforts,we designed and synthesized a potent FXR agonist,LZ-007(EC50=75.5 nM).To evaluate the pharmacokinetic properties of LZ-007 in vitro and in vivo,the efficacy of LZ-007 in the treatment of NAFLD,and the safety of long-term administration.Detailed experimental results are as follows:(1)We systematically researched the stability of LZ-007 in different hepatic microsomes in vitro.Then,we found that LZ-007 showed stability in the liver microsomes of SD rats,mice,beagles,humans,and rhesus monkeys in vitro.Meanwhile,we observed the pharmacokinetics of LZ007 in vivo.The bioavailability of LZ-007 was 57.65%in vivo,the peak time was 1.5 h,and the half-life was 4.42 h.Therefore,these results indicated that LZ-007 is well absorbed in animals and suitable for oncedaily administration.Then,we found that LZ-007 was mainly distributed in the liver and ileum,both of which were pharmacodynamic target organs in the study of tissue distribution.In addition,LZ-007 can effectively stimulate FXR and regulate downstream target genes in target gene studies in vivo.(2)In a preclinical animal study of the db/db mouse model,we observed the prevention and treatment of NAFLD by LZ-007(20 mg/kg).The results showed that LZ-007 could decrease blood lipids and lipid accumulation in the liver.Furthermore,LZ-007 regulated levels of genes involved in lipid synthesis and metabolism,fatty acid β oxidation,and oxidative stress to alleviate fatty liver disease.(3)NASH mouse model established by HFD+HFC diet combined with an intraperitoneal injection of CCl4.To evaluate the potential efficacy of LZ-007 in NASH mice,we evaluated the effects of LZ-007 on lipid synthesis and metabolism,oxidative stress,inflammation,and fibrosis in NASH mice.The results showed that the lowest therapeutic dose of LZ007 in mice was 5 mg/kg and had a dose-dependent therapeutic effect.Especially at doses of 10 and 20 mg/kg,LZ-007 was comparable to OCA(20 mg/kg)for NAFLD in vivo.Simultaneously,LZ-007(20 mg/kg)was significantly better than OCA in liver balloon lesions,liver TC and NEFA content,and regulation of lipid metabolism-related genes(ApoC-II,ANGTPL3,SREBP-1C).In addition,LZ-007 also decreased inflammatory markers(IL-1β,MCP-1)and liver fibrosis markers(α-SMA).(4)No apparent toxic symptoms were induced by LZ-007(250 and 500 mg/kg)at the therapeutic dose of 12.5 or 25 times in subchronic toxicological studies.There was no difference in biochemical parameters between the administration group and the healthy group.Moreover,LZ007 has no noticeable toxic effect on the brain,heart,lung,liver,spleen,and kidney.In summary,our study comprehensively evaluated the pharmacokinetics of compound LZ-007 in vitro and in vivo,its therapeutic effect on NAFLD,and its safety in long-term administration.As expected,LZ-007 has outstanding aspects of anti-NAFLD activity and pharmacokinetic properties in vitro and in vivo.LZ-007 not only has excellent long-term efficacy but was not toxic to the functioning of the liver,kidneys,heart,brain,lungs,and spleen.Excitingly,we discovered that LZ007 was more efficient than OCA in vivo,which is presently a popular candidate for Phase 3 NASH.