Renchao Dong1, Xiaobo Yang2, Changyuan Wang1, Kexin Liu1, Zhihao Liu1, Xiaodong Ma2, Huijun Sun1, Xiaokui Huo1, Ting Fu3, Qiang Meng4. 1. Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian 116044, China; Key Laboratory of Pharmacokinetics and Transport of Liaoning Province, Dalian Medical University, Dalian 116044, China. 2. Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian 116044, China. 3. Pharmacy Department of Affiliated Zhongshan hospital of Dalian University, Dalian, China. 4. Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian 116044, China; Key Laboratory of Pharmacokinetics and Transport of Liaoning Province, Dalian Medical University, Dalian 116044, China. Electronic address: qiangmeng@dlmedu.edu.cn.
Abstract
BACKGROUD: Non-alcoholic fatty liver disease (NAFLD) is currently evolving as the most common liver disease worldwide. Dyslipidemia, pathoglycemia and insulin resistance are the major risk factors for the development of NAFLD. To date, no effective drug therapies for this condition have been approved. PURPOSE: The present study was to investigate the protective effects of yangonin, a kavalactone isolated from Kava, against NAFLD and further elucidate the mechanisms in vivo and in vitro. STUDY DESIGN: A high-fat diet (HFD) induced mouse NAFLD model was used with or without yangonin treatment. METHODS: The body weight, relative liver weight and serum biochemical indicators were measured. H&E and Oil Red O staining were used to identify the amelioration of the liver histopathological changes. Serum and hepatic triglyceride, free fatty acids and total cholesterol were analyzed. siRNA, quantitative real-time PCR and Western blot assay were used to clarify the mechanisms underlying yangonin protection. RESULTS: Yangonin had obvious protective effects against NAFLD via farnesoid X receptor (FXR) activation. Through FXR activation, yangonin attenuated lipid accumulation in the liver via inhibition of hepatic lipogenesis-related protein including sterol regulatory element-binding protein 1c (SREBP-1c), fatty acid synthetase (FAS), acetyl-CoA carboxylase 1 (ACC1) and stearoyl-CoA desaturase 1 (SCD1). Besides, yangonin promoted lipid metabolism through an induction in genes required for lipoprotein lipolysis and fatty acid β-oxidation. Furthermore, yangonin modulated blood glucose homeostasis through regulation of gluconeogenesis-related gene phosphoenol pyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), and glycogen synthesis-related gene glycogen synthase kinase 3β (GSK3β) and pyruvate dehydrogenase (PDase). Also, yangonin increased insulin sensitivity through upregulating phosphorylation of insulin responsive substrate 1, 2 (IRS-1 and IRS-2). Then, in vivo and in vitro evidence further demonstrated the involvement of FXR activation in yangonin hepatoprotection. CONCLUSIONS: Yangonin protects against NAFLD due to its activation of FXR signalling to inhibit hepatic lipogenesis and gluconeogenesis, and to promote lipid metabolism and glycogen synthesis, as well as insulin sensitivity.
BACKGROUD: Non-alcoholic fatty liver disease (NAFLD) is currently evolving as the most common liver disease worldwide. Dyslipidemia, pathoglycemia and insulin resistance are the major risk factors for the development of NAFLD. To date, no effective drug therapies for this condition have been approved. PURPOSE: The present study was to investigate the protective effects of yangonin, a kavalactone isolated from Kava, against NAFLD and further elucidate the mechanisms in vivo and in vitro. STUDY DESIGN: A high-fat diet (HFD) induced mouse NAFLD model was used with or without yangonin treatment. METHODS: The body weight, relative liver weight and serum biochemical indicators were measured. H&E and Oil Red O staining were used to identify the amelioration of the liver histopathological changes. Serum and hepatic triglyceride, free fatty acids and total cholesterol were analyzed. siRNA, quantitative real-time PCR and Western blot assay were used to clarify the mechanisms underlying yangonin protection. RESULTS: Yangonin had obvious protective effects against NAFLD via farnesoid X receptor (FXR) activation. Through FXR activation, yangonin attenuated lipid accumulation in the liver via inhibition of hepatic lipogenesis-related protein including sterol regulatory element-binding protein 1c (SREBP-1c), fatty acid synthetase (FAS), acetyl-CoA carboxylase 1 (ACC1) and stearoyl-CoA desaturase 1 (SCD1). Besides, yangonin promoted lipid metabolism through an induction in genes required for lipoprotein lipolysis and fatty acid β-oxidation. Furthermore, yangonin modulated blood glucose homeostasis through regulation of gluconeogenesis-related gene phosphoenol pyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), and glycogen synthesis-related gene glycogen synthase kinase 3β (GSK3β) and pyruvate dehydrogenase (PDase). Also, yangonin increased insulin sensitivity through upregulating phosphorylation of insulin responsive substrate 1, 2 (IRS-1 and IRS-2). Then, in vivo and in vitro evidence further demonstrated the involvement of FXR activation in yangonin hepatoprotection. CONCLUSIONS: Yangonin protects against NAFLD due to its activation of FXR signalling to inhibit hepatic lipogenesis and gluconeogenesis, and to promote lipid metabolism and glycogen synthesis, as well as insulin sensitivity.
Authors: Tengfei Bian; Pedro Corral; Yuzhi Wang; Jordy Botello; Rick Kingston; Tyler Daniels; Ramzi G Salloum; Edward Johnston; Zhiguang Huo; Junxuan Lu; Andrew C Liu; Chengguo Xing Journal: Nutrients Date: 2020-10-05 Impact factor: 5.717