Study on chemical composition analysis and lipid metabolism regulation activity of different parts of Eucommia ulmoides

Abstract Eucommia ulmoides has lipid-lowering, antihypertensive, hypoglycemic and anti-aging effects. The main medicinal part of Eucommia ulmoides bark (EBE), but its slow growth and peeling easily lead to tree death, which limits the extensive use of Eucommia ulmoides resources and causes the lack of Eucommia ulmoides resources. It is not clear whether Eucommia ulmoides leaves (ELE), flowers (EFE) and seeds (ESE) can be used as substitutes for Eucommia ulmoides bark. In this study, UPLC-Q-Orbitrap-MS was used to analyze the active ingredients in the bark, leaves, flowers and seeds of Eucommia ulmoides. HPLC method was established for the determination of 8 common active ingredients in the bark, leaves, flowers and seeds of Eucommia ulmoides. The content of active ingredients is also based on the current research on Eucommia ulmoides, and the regulation activity of lipid metabolism was compared. The results showed that 119 compounds were identified from 12 classes of Eucommia ulmoides, and the skin and leaves of Eucommia ulmoides contained a lot of the same active ingredients. The content of turbinol diglucoside in Eucommia ulmoides bark was the highest, and the content of chlorogenic acid in Eucommia ulmoides leaves was the highest. After Eucommia intervention, all indexes of cell model were improved and lipid metabolism regulation ability was improved: EBE, ELE, EFE, ESE; EBE and ELE had similar lipid lowering effect. After Eucommia's treatment, mRNA expression of AMPK increased in a volume-dependent manner, while mRNA expression of SREBP-1c, FAS and ACC decreased in a volume-dependent manner. Therefore, Eucommia's improvement in steatosis of HepG2 cells may be related to the regulation of AMPK, SREGP-1C, FAS and ACC signaling pathways. In conclusion, it can be concluded that Eucommia ulmoides leaves can replace Eucommia ulmoides skins in the regulation of lipid metabolism and improve the comprehensive utilization of Eucommia ulmoides resources.