Abstract
We investigated the effect of purified withanolides and extracts derived from Ashwagandha on steatosis, the abnormal accumulation of fat that can lead to non-alcoholic fatty liver disease (NAFLD). Collaborator of ARF (CARF, also known as CDKN2AIP, a protein that regulates hepatic lipid metabolism, fat buildup, and liver damage) was used as an indicator. Six withanolides (Withaferin A, Withanone, Withanolide B, Withanoside IV, Withanoside V, and Withanostraminolide-12 deoxy) reversed the decrease in CARF caused by exposure to free fatty acids (FFAs) in liver-derived cells (HepG2 hepatocytes). After analyzing the effects of these withanolides on CARF mRNA and protein levels, FFA accumulation, protein aggregation, and oxidative and DNA damage stresses, we selected Withaferin A and Withanone for molecular analyses. Using the palmitic-acid-induced fatty acid accumulation stress model in Huh7 cells, we found a significant reduction in the activity of the key regulators of lipogenesis pathways, including sterol regulatory element-binding protein-1c (SREBP-1c), fatty acid synthase (FASN), and peroxisome proliferator-activated receptors (PPARγ and PPARα). This in vitro study suggests that low, non-toxic doses of Withaferin A, Withanone, or Ashwagandha extracts containing these withanolides possess anti-steatosis and antioxidative-stress properties. Further in vivo and clinical studies are required to investigate the therapeutic potential of these Ashwagandha-derived bioactive ingredients for NAFLD.