Metabolic associated fatty liver disease （MAFLD） is a liver disease associated with metabolic disorders， and it is characterized by excessive fat deposition in hepatocytes and is closely associated with insulin resistance and genetic susceptibility. Aging is an important factor in the progression of MAFLD and is positively correlated with the mortality rate of patients with MAFLD. The pathophysiological mechanisms of MAFLD involve lipid metabolism disorders， insulin resistance， inflammation， and oxidative stress， and aging exacerbates the pathological process of MAFLD by further affecting these key mechanisms. Cell senescence is an important factor in organismal aging， and therapeutic strategies targeting senescent cells can reduce the number of senescent cells or inhibit the inflammatory factors secreted by such cells， thereby helping to slow down the progression of MAFLD. In addition， the screening of novel regulatory factors provides new targets for the development of new drugs for MAFLD treatment. Although several anti-aging therapies have entered clinical trials， further studies are needed to validate the specificity and potential liver damage of these therapies due to the complex mechanisms of aging on the liver. Transforming multisystem metabolic dysfunction therapies for MAFLD into specialized therapies for aging may provide new ideas for MAFLD drug development.

Inflammatory liver injury is the initiating factor for various chronic liver diseases.It can involve the whole body,and on the contrary,systemic diseases may also lead to liver injury.The diagnosis and treatment of liver disease should not only consider the liver disease itself,but also understand the interaction between various systemic diseases and inflammatory liver injury and related pathophysiological mechanisms.Therefore,the diagnosis and treatment of liver injury often require multidisciplinary discussions and joint decision-making.One of the important links in the treatment of liver disease is to protect and maintain the stability of liver function,and how to carry out anti-inflammatory and liver-protecting treatment should be considered during the development of treatment strategies.Bicyclol is a chemical agent independently developed by China and is used for the treatment of inflammatory liver injury.Bicyclol has a good clinical effect in the prevention and treatment of inflammatory liver injury due to various causes and has been registered and listed in nine countries along the Belt and Road.Therefore,we have organized domestic experts from relevant disciplines all over the country to summarize the advances in the multidisciplinary clinical application of bicyclol in the prevention and treatment of inflammatory liver injury based on related guidelines/consensus statements/clinical pathways and evidence-based medicine and with reference to the clinical practice in China,in order to improve the scientific and standard use of bicyclol in clinical practice and the prevention and treatment of inflammatory liver injury in each discipline.

Non-alcoholic fatty liver disease(NAFLD)constitutes a series of histological lesions characterized by varying degrees of hepatocyte damage,fat accumulation,inflammation,and fibrosis.Currently,liver biopsy is considered the"gold standard"for evaluating the degree of hepatic steatosis,inflammation,and fibrosis,and it also serves as the cornerstone for accurate grading of NAFLD.This article reviews the value and application of liver biopsy in the clinical diagnosis,staging,and clinical trials of NAFLD.

Liver disease is a serious public health problem worldwide, affecting human health. However, there are still many unmet needs for the treatment of liver disease, especially with new therapeutic drugs. At present, there is no treatment method to eradicate the hepatitis B virus, nor are there therapeutic drugs for liver fibrosis, liver failure, and others. Chemotherapy and targeted immunotherapy are still unsatisfactory for liver cancer. This article provides an overview of the current status and challenges that arise in new drug research and development for liver diseases.

Metabolic dysfunction-associated fatty liver disease (MASLD) is a major public health problem that seriously affects human health. At present, some good progress has been made in the research and development of new drugs for MASLD, but there is still great space for exploration. This paper summarizes and analyzes the reasons in the current clinical status and challenges for the research and development of new drugs for MASLD.

Liver fibrosis is a key step in the developmental process of various chronic liver diseases, including cirrhosis. Therefore, the focus and difficulty of liver disease research have always been on how to reverse liver fibrosis. However, due to complex mechanisms, difficulties in endpoint evaluation, a lack of non-invasive diagnostic methods, and other factors, the research and development of new drugs are hindered and lengthy. Currently, some new drugs are being researched and developed, which signifies the prospect is optimistic.

Liver biopsy is an important means of clinical diagnosis and treatment of liver diseases, but it is not easily accepted by patients because of its invasiveness. The most commonly employed liver biopsy approaches are percutaneous or transjugular. Endoscopic ultrasound-guided liver biopsy (EUS-LB), a newly emerging transjugular technique, has been widely studied and applied in recent years, but its application in China is less common. The EUS-LB has the advantages of high safety and comfort, simultaneous sampling of both liver lobes, and adequate sampling volume; however, it also has the disadvantages of high requirements for hardware, operators, and cost. This article reviews the clinical application of EUS-LB in accordance with pertinent research findings from recent years and discusses its advantages, disadvantages, and implementation feasibility.

Liver disease is one of the most important health problems around the world， and early diagnosis and timely intervention and treatment are the key to preventing liver-related morbidity and mortality rates. The development of endoscopic techniques has provided new diagnostic and intervention methods for liver diseases. This article reviews the application and development of endoscopic techniques in liver diseases from the following aspects： the technical advances and advantages of endoscopic ultrasound-guided liver biopsy； the application and development of endoscopic techniques in the treatment of portal hypertension caused by liver abscess/hepatic cyst and liver diseases， as well as interventional techniques in the treatment of liver tumors； the efficacy and prospects of the endoscopic techniques for weight loss， which are relatively new in China， in the treatment of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis. Endoscopic techniques may hold promise for wide clinical application and exploration in in liver-related diseases in China， so as to provide more options for patients and doctors.

With the rapid increase in the prevalence rate of nonalcoholic fatty liver disease (NAFLD), new treatment methods are needed to prevent disease progression to liver fibrosis, liver cirrhosis, and liver cancer. Although great efforts have been made to clarify the pathological mechanisms of NAFLD disease progression, there are still no effective treatment methods at present. Bile acids (BAs) regulate systemic metabolism by activating nuclear receptors and G protein-coupled receptors and have been identified as important signaling molecules involved in lipid, glucose, and energy metabolism. Dysregulation of BA homeostasis is associated with the severity of NAFLD. This article summarizes the important ligands in BA metabolism and their role in the progression of NAFLD, in order to provide a basis for the treatment of NAFLD by targeting BA messengers.

Cholestatic liver diseases (CLD) are a series of diseases due to impaired bile flow and accumulation of bile acid in the liver and/or systemic circulation caused by immune, genetic, and environmental factors. The pathogenesis of CLD remains unclear and CLD is difficult to treat. As a substitute for human diseases, animal models can provide a platform for exploring the etiology and pathogenesis of the disease and finding appropriate therapeutic targets. This article reviews the current research advances in the animal models of CLD.