The effect of white tea in an animal model of diet-induced non alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) represents a major public health concern worldwide due to its increasing prevalence, complex pathogenesis, and the lack of effective pharmacological treatment options. The development of the disease is influenced by multiple factors, including insulin resistance, obesity, lipotoxicity, alterations in gut microbiota, and oxidative stress. In the present study, a NAFLD model was induced in male Wistar Albino rats using a methionine- and choline-deficient (MCD) diet, and the therapeutic effects of white tea and its predominant catechin, epigallocatechin-3-gallate (EGCG), were evaluated. The study design consisted of four groups, each comprising seven animals: Control, NAFLD, NAFLD + White Tea (WT), and NAFLD + EGCG. The effects of white tea and EGCG were assessed by measuring serum levels of AST, ALT, ALP, total cholesterol (TC), and triglycerides (TG); hepatic levels of TNF-α, IL-1β, GLP-1, MMP-9, TBARS, and total thiols (TT); as well as DPP-4 enzyme activity. In addition, for histological and immunohistochemical analyses, liver tissue was examined under light microscopy to assess hepatocytes and to detect the immunopositivity of 8-OHdG, Caspase-3, and NF-κB/p65. Compared with the NAFLD group, the WT group demonstrated significant reductions in AST, ALT, ALP, and TG levels, whereas the EGCG group exhibited a marked decrease in TC levels. Interestingly, TC levels were significantly elevated in the WT group compared with both the Control and NAFLD groups. Relative to NAFLD, both EGCG and WT treatment reduced TBARS, TNF-α, and IL-1β levels, while increasing TT levels. Notably, white tea exerted pronounced lipid-regulating and antioxidant effects. DPP-4 inhibition was significantly reduced in the NAFLD group compared with controls, whereas treatment with EGCG and WT markedly enhanced DPP-4 inhibition. However, no significant intergroup differences were observed in GLP-1 levels. Histological evaluation revealed hepatocellular degeneration and increased positivity for 8-OHdG, Caspase-3, and NF-κB/p65 in the NAFLD group, all of which were ameliorated by EGCG and WT treatment. Collectively, these findings indicate that EGCG and white tea specific to the Rize region may attenuate liver injury in NAFLD by modulating oxidative stress and inflammatory responses. The synergistic effects of polyphenols present in white tea suggest that, compared to EGCG alone, white tea may exert broader and more comprehensive biological activity, highlighting its potential as a natural therapeutic agent in NAFLD.