ZONG Bin, LI Ran, QIAN Yuanxia, et al
2025, 35(03): 197-211.
Objective: To explore the effect of Bupleurum extract on non-alcoholic fatty liver disease (NAFLD) and its relationship with amine oxidase copper-containing 3 (AOC3)-phosphatidylinositol 3-KINASE (PI3K)/protein kinase B (AKT) signaling pathway. Methods: A total of 69 patients with NAFLD in Zhenjiang Hospital of Chinese Traditional and Western Medicine from May 2022 to May 2023, and another 70 healthy controls were enrolled in the study. The contents of phenylalanine (Phe) and tyrosine (Tyr) in serum were measured by ELISA. The relative expressions of AOC3 mRNA and protein in serum were detected by qRT-PCR and Western blotting, respectively. The NAFLD model of C57BL/6 mice was constructed. After modeling, they were divided into control group, model group, and low-dose group (50 mg/kg), medium-dose group (75 mg/kg), and high-dose group (100 mg/kg) of Bupleurum extract, with 6 mice in each group. The Bupleurum extract group was given the corresponding Bupleurum extract, the control group and the model group were given corresponding volumes of normal saline by gavage every day, respectively. Four weeks later, the contents of total cholesterol (TC), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-α) in serum were detected by ELISA. Additionally, superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels in liver tissues were measured. Hepatic pathology was evaluated by hematoxylin-eosin (HE) staining. The siRNA2 (50 nmol/L) was screened out by knocking down the expression of AOC3 by siRNA transfection. Hepatocytes were divided into control group, model group, siRNA2 group (50 nmol/L), Bupleurum group (100 μg/mL), and combined group (50 nmol/L siRNA2 + Bupleurum 100 μg/mL). The cell proliferation rate, apoptosis rate and the protein expressions of p-PI3K and p-AKT were detected by MTT, flow cytometry and Western blotting, respectively. Results: The contents of Phe and Tyr in the serum of patients with NAFLD and model mice, as well as the relative expression levels of AOC3 mRNA and protein, were significantly higher than those of healthy individuals and the control group, respectively (P<0.01). Compared with the model group, the levels of Phe, Tyr, TC, TG, LDL-C, NO and TNF-α in the serum of mice in the medium and highdose Bupleurum groups were significantly decreased (P<0.05 or P<0.01), the level of HDL-C was significantly increased (P<0.01), and liver fibrosis and reactive oxygen species accumulation were significantly attenuated (P<0.01). Compared with the siRNA2 group and the Chaihu group, the proliferation rate of hepatocytes in the combined group was significantly increased (P<0.01), the apoptosis rate was greatly decreased (P<0.01), the contents of lipotoxic metabolites (TG, TC) were significantly decreased (P<0.01), and oxidative stress was significantly inhibited (decreased content of MDA, increased SOD/GSH-Px, P<0.01 or P<0.05), liver function was significantly improved (decreased contents of ALT and AST, P<0.01), and the PI3K/AKT signaling pathway was activated (the expressions of AOC3, p-PI3K, and p-AKT decreased, P<0.01). Conclusion: Bupleurum extract may attenuate NAFLD by regulating the metabolism of amino acids related to NAFLD, reducing the content of peroxides, blocking the excessive activation of the PI3K/AKT pathway mediated by AOC3, reducing the expression of AOC3 and phosphorylating the expression of PI3K/AKT.