Liupao Tea Ameliorates High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease via Arginine Metabolism: Insights From Metabolomics and Network Pharmacology

Abstract

Non-alcoholic fatty liver disease (NAFLD) has become a prominent public health concern, closely linked to metabolic syndromes. Liupao tea (LT), a traditional Chinese dark tea, has demonstrated hepatoprotective effects by regulating metabolism. This study investigated the protective effects of LT on HFD-induced NAFLD using metabolomics and network pharmacology approaches. We found that LT significantly reduced energy intake in HFD-fed rats, attenuated abnormal visceral fat accumulation, and prevented hyperlipidemia, abnormal liver lipid deposition, and liver steatosis. Serum untargeted metabolomic analysis identified 46 differential metabolites as potential biomarkers associated with 10 metabolic pathways, including arginine and proline metabolism. Network pharmacology suggested that LT exerts its hepatoprotective effects by regulating arginine metabolism and inflammatory factors; key components, such as caffeine and epigallocatechin gallate, showed direct relevance to NAFLD. Following the intervention, targeted metabolomic analysis revealed a significant change in the levels of 18 relevant amino acids, confirming LT's impact on arginine metabolism. Immunohistochemical results demonstrated reduced expression of inflammatory factors (TNF-α, IL-6, IL-1β) in the liver, suggesting improved liver health. Collectively, these findings indicate that LT mitigates HFD-induced NAFLD through regulation of amino acid metabolism and reduction of inflammatory factors, thereby alleviating liver injury.