Leaves of Lippia triphylla improve hepatic lipid metabolism via activating AMPK to regulate lipid synthesis and degradation

Abstract

Diabetes is a chronic disease associated with triglyceride metabolism disorder, being an etiological factor in fatty liver disease, hypertension, and cardiovascular diseases. Diet-based therapy including energy balance and herbal supplements is a suitable approach to ameliorate progression of the disease. Leaves of Lippia triphylla (lemon verbena) from the family Verbenaceae are a foodstuff used as a tea drink or cooking seasoning, with confirmed safety during long-term use. We report herein the regulatory effect of L.\xa0triphylla extract (LTE) and its major compound acteoside (ACT) on abnormal liver lipid metabolism. Both LTE and ACT administration significantly decreased serum and hepatic lipid content, increased the phosphorylation level of the energy metabolism moderator adenosine 5′-monophosphate-activated protein kinase (AMPK), and reduced two major markers of lipid synthesis, viz. acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), with an obvious enhancement in ACC phosphorylation. Furthermore, ACT promoted lipolysis and fatty acid oxidation by increasing messenger RNA (mRNA) expression of adipose triglyceride lipase (ATGL) and carnitine palmitoyltransferase (CPT)-1. These results provide scientific evidence for the development of functional foods containing L.\xa0triphylla extract and acteoside for treatment of diabetes-associated lipid metabolism disorder.