Non-alcoholic fatty liver disease (NAFLD), characterized by hepatic steatosis, is a common metabolic liver disease worldwide. Currently, satisfactory drugs for NAFLD treatment remain lacking. Obesity and diabetes are the leading causes of NAFLD, and compounds with anti-obesity and anti-diabetic activities are considered suitable candidates for treating NAFLD. In this study, biochemical and histological assays revealed that a natural lignan schisanhenol (SAL) effectively decreased lipid accumulation and improved hepatic steatosis in free fatty acid (FFA)-treated HepG2 cells and high-fat diet (HFD)-induced NAFLD mice. Further, molecular analyses, microRNA (miRNA)-seq, and bioinformatics analyses revealed that SAL may improve NAFLD by targeting the miR-802/adenosine monophosphate-activated protein kinase (AMPK) pathway. Liver-specific overexpression of miR-802 in NAFLD mice significantly impaired SAL-mediated liver protection and decreased the protein levels of phosphorylated (p)-AMPK and PRKAB1. Dual-luciferase assay analysis further confirmed that miR-802 inhibits hepatic AMPK expression by binding to the 3ʹ untranslated region of mouse Prkab1 or human PRKAA1. Additionally, genetic silencing of PRKAA1 blocked SAL-induced AMPK pathway activation in FFA-treated HepG2 cells. The results demonstrate that SAL is an effective drug candidate for treating NAFLD through regulating miR-802/AMPK-mediated lipid metabolism.
The fruits of Schisandra chinensis (SCF) and Schisandra sphenanthera (SSF) are traditional Chinese herbal medicines classified as medicinal and food homologous materials, known for their significant neuroprotective efficacy. However, the differences in their therapeutic effects and active components for the treatment of vascular cognitive impairment (VCI) remain unclear. This study aimed to elucidate the neuroprotective activities of SCF and SSF on VCI and investigate the compositional disparities between the two. The lipopolysaccharide-induced and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced BV2 cell models were used to evaluate the protective effects of SCF and SSF against neuroinflammation and mitochondrial damage, respectively. The therapeutic effects were further validated using a bilateral common carotid artery stenosis mouse model. Compositional differences were analyzed using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), and drug-like properties of their constituents were assessed. In vitro experiments showed that SCF and SSF at concentrations of 6.4, 16, and 40 μg/mL reduced nitric oxide, tumor necrosis factor-alpha, and interleukin-6 levels in a dose-dependent manner. Notably, at the same concentrations, SCF significantly mitigated OGD/R-induced mitochondrial damage, whereas SSF showed no significant effect. Compared with SSF, SCF exhibited stronger anti-neuroinflammatory and antioxidant properties. In vivo experiments further demonstrated that SCF, administered at 400 mg/kg, was more effective in improving learning ability, spatial learning and memory, cerebral blood flow, and nerve fiber repair than SSF. Moreover, 71 and 64 compounds were identified in SCF and SSF, respectively, using UPLC-Q-TOF/MS. Drug-like property analysis of these compounds revealed that the superior therapeutic effects of SCF may be attributed to differences in biphenylcyclooctene-type lignans. Our data support the conclusion that SCF possesses significantly superior neuroprotective activity compared to SSF, providing a theoretical basis for its clinical application in VCI.