Hepatoprotective Effects of Liubao Tea Polyphenols against CCl₄-Induced Liver Injury in Mice via Antioxidant Activity | Chapter 7 | Molecular Mechanisms and Signaling Pathways of the Anti-inflammatory Effects of Functional Foods

Active oxygen free radicals cause oxidative stress, which is a common pathophysiological mechanism of liver diseases. Tea polyphenols can sequester lipid peroxidation free radicals during the peroxidation process, lower polyphenolic free-radical content, and interrupt free-radical oxidation chain reactions, thereby effectively removing free radicals. This study investigated the protective effect of Liubao tea polyphenols (PLT) against carbon tetrachloride (CCl₄)-induced liver injury in mice. Mice were pretreated with PLT prior to the administration of CCl₄ (10 mL/kg) to induce hepatic damage. Subsequently, liver and serum biochemical parameters, along with the expression levels of relevant messenger RNAs (mRNAs) and proteins in liver tissue, were assessed. The results demonstrated that PLT administration significantly ameliorated liver injury, as indicated by reduced liver indices and improved histological architecture. Specifically, PLT downregulated serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglycerides (TGs), and malondialdehyde (MDA), while elevating the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Furthermore, PLT decreased the serum concentrations of pro-inflammatory cytokines, including interleukin-6 (IL-6), IL-12, tumour necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Histopathological examination revealed that PLT attenuated CCl₄-induced central venous alterations and hepatocellular damage. At the molecular level, quantitative PCR and Western blot analyses confirmed that PLT upregulated the mRNA and protein expression of antioxidant enzymes—Cu/Zn-SOD, Mn-SOD, catalase (CAT), and GSH-Px—as well as the NF-κB inhibitor IκB-α in liver tissues. Conversely, PLT downregulated the expression of cyclooxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB). Additionally, PLT increased the protein levels of phosphorylated NF-κB p65 (p-NF-κB p65) and cytochrome P450 reductase in injured livers. PLT comprises several bioactive compounds, such as gallic acid, catechin, caffeine, epicatechin (EC), epigallocatechin gallate (EGCG), gallocatechin gallate (GCG), and epicatechin gallate (ECG), which may contribute to its broad biological activities. In conclusion, PLT exerts a preventive effect against CCl₄-induced liver injury, comparable to that of silymarin, likely through the modulation of oxidative stress and inflammatory pathways. In this study, toxic carbon tetrachloride was used to simulate chemical-induced liver injury, and the observed effects remained at the laboratory level. In order to better prove this study’s argument, future research on the human body is expected. The role of PLT in liver injury needs to be further studied, which will be conducive to more obvious discoveries of the link between its active components and their mechanisms. At the same time, in view of the mechanism of PLT, it is necessary to verify the mechanism more accurately for the differences across PLT components in the future.

 

 

Author(s) Details

Yanni Pan
Chongqing Collaborative Innovation Center for Functional Food, Chongqing University of Education, Chongqing 400067, China, Chongqing Engineering Research Center of Functional Food, Chongqing University of Education, Chongqing 400067, China, Chongqing Engineering Laboratory for Research and Development of Functional Food, Chongqing University of Education, Chongqing 400067, China, College of Biological and Chemical Engineering, Chongqing University of Education, Chongqing 400067, China and Department of Food Science and Biotechnology, Cha University, Gyeongghi-do 487-010, South Korea.

 

Xingyao Long
Chongqing Collaborative Innovation Center for Functional Food, Chongqing University of Education, Chongqing 400067, China, Chongqing Engineering Research Center of Functional Food, Chongqing University of Education, Chongqing 400067, China, Chongqing Engineering Laboratory for Research and Development of Functional Food, Chongqing University of Education, Chongqing 400067, China and College of Biological and Chemical Engineering, Chongqing University of Education, Chongqing 400067, China.

 

Ruokun Yi
Chongqing Collaborative Innovation Center for Functional Food, Chongqing University of Education, Chongqing 400067, China, Chongqing Engineering Research Center of Functional Food, Chongqing University of Education, Chongqing 400067, China and Chongqing Engineering Laboratory for Research and Development of Functional Food, Chongqing University of Education, Chongqing 400067, China.

 

Xin Zhao
Chongqing Collaborative Innovation Center for Functional Food, Chongqing University of Education, Chongqing 400067, China, Chongqing Engineering Research Center of Functional Food, Chongqing University of Education, Chongqing 400067, China and Chongqing Engineering Laboratory for Research and Development of Functional Food, Chongqing University of Education, Chongqing 400067, China.

 

Please see the book here :- https://doi.org/10.9734/bpi/mono/978-81-998509-0-3/CH7