Silymarin protects against renal injury through normalization of lipid metabolism and mitochondrial biogenesis in high fat-fed mice

• Published in: Free radical biology & medicine 2017-09, Vol.110, p.240-249
• Main Authors: Bin Feng, Meng, Ran, Bin Huang, Bi, Yan, Shen, Shanmei, Zhu, Dalong
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants - pharmacology; Cell Line; Diet, High-Fat - adverse effects; Epithelial Cells - drug effects; Epithelial Cells - metabolism; Epithelial Cells - pathology; Fatty acid β-oxidation; Humans; Kidney injury; Kidney Tubules, Proximal - drug effects; Kidney Tubules, Proximal - metabolism; Kidney Tubules, Proximal - pathology; Lipid Metabolism - drug effects; Male; Membrane Potential, Mitochondrial - drug effects; Mice; Mice, Inbred C57BL; Mitochondria - drug effects; Mitochondria - metabolism; Mitochondrial biogenesis; Obesity; Obesity - diet therapy; Obesity - etiology; Obesity - metabolism; Obesity - pathology; Oxidation-Reduction; Oxidative Stress - drug effects; Palmitic Acid - antagonists & inhibitors; Palmitic Acid - pharmacology; Protective Agents - pharmacology; Renal Insufficiency, Chronic - diet therapy; Renal Insufficiency, Chronic - etiology; Renal Insufficiency, Chronic - metabolism; Renal Insufficiency, Chronic - pathology; Silymarin; Silymarin - pharmacology
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2017.06.009

Obesity is associated with an increased risk of chronic kidney diseases and the conventional treatment with renin-angiotensin-aldosterone system (RAAS) inhibitors is not enough to prevent renal injury and prolong the progression of disease. Recently, silymarin has shown protective effects on renal tissue injury, but the underlying mechanisms remain elusive. The goal of this study was to investigate the potential capacity of silymarin to prevent renal injury during obesity induced by high fat diet (HFD) in mice. In vivo, male C57BL/6 mice received HFD (60% of total calories) for 12 weeks, randomized and treated orally with vehicle saline or silymarin (30mg/kg body weight/d) for 4 weeks. In vitro, human proximal tubular epithelial cells (HK2) were exposed to 300μM palmitic acid (PA) for 36h followed by silymarin administration at different concentrations. The administration of silymarin significantly ameliorated HFD induced glucose metabolic disorders, oxidative stress and pathological alterations in the kidney. Silymarin significantly mitigated renal lipid accumulation, fatty acid β-oxidation and mitochondrial biogenesis in HFD mice and PA treated HK2 cells. Furthermore, silymarin partly restored mitochondrial membrane potential of HK2 cells after PA exposure. In conclusion, silymarin can improve oxidative stress and preserve mitochondrial dysfunction in the kidney, potentially via preventing accumulation of renal lipids and fatty acid β-oxidation. [Display omitted] •Silymarin prevents HFD induced kidney hypertrophy and glomerulopathy.•Silymarin attenuates renal lipid accumulation and ROS production in HFD mice.•Silymarin mitigates HFD induced lipid synthesis and fatty acid β-oxidation.•Impaired mitochondrial Δψm and ATP reduction are restored by silymarin treatment.