Study on the protective effect of puerarin on acute liver injury in rats based on the IL-6/JAK2/STAT3 signaling pathway
Acute liver injury is a sudden liver dysfunction disease induced by drug poisoning, immune damage, viral infection, and other reasons in the short term. Currently, there are many methods for treating liver injury, and Western medicine has obvious therapeutic effects but many adverse drug reactions and high prices. Liver transplantation treatment methods also have a series of problems such as lack of supply, multiple complications, and high mortality rate. The previous research of the research group found that traditional Chinese medicine showed unique efficacy in the prevention and treatment of liver injury, especially that traditional Chinese medicine extracts and traditional Chinese medicine monomer compounds played a significant role in antioxidation and regulating inflammatory reaction, which could effectively reduce the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and the release of inflammatory factors in rats with CCl4 induced acute liver injury, increase the activity of glutathione peroxidase (GSH Px), superoxide dismutase (SOD) and other antioxidant enzymes, and play an anti-inflammatory and antioxidant role in improving liver injury. In recent years, traditional Chinese patent medicines and simple preparations such as Yinzhihuang injection solution, silymarin tablets have also been developed to treat liver injury and have clinical efficacy Significant, but the mechanism of action is still unclear. Bergenin is a white loose acicular crystal or crystalline powder compound, chemical formula C14H16O9, relative molecular weight 328.27, which is easily soluble in methanol and slightly soluble in water or ethanol. This compound exists in the whole herb of Saxifragaceae, rock cabbage with thick leaves, and the rhizome and leaves of Zijinniu Bailiang gold. It is a common folk medicine, distributed in southwest Sichuan, Hunan, northern Yunnan, southern and eastern Xizang, also known as Saxifragenin, dwarf tea, rock cabbage fat, bergamot, etc. It has good biological activities such as anti-inflammatory, anticancer, antiviral, immune regulation, anti arrhythmia, etc., and is commonly used in clinical practice to treat chronic bronchitis. At present, there is relatively little research on the hepatoprotective effect of puerarin. Therefore, we induced a rat model of acute liver injury with CCl4, explored the protective effect of puerarin on rats with acute liver injury, screened new hepatoprotective drugs, and explored its mechanism of action in treating acute liver injury to improve the targeting of traditional Chinese medicine prevention and treatment, providing a basis for the clinical application and development of drugs.

The liver is the largest parenchymal organ in the human body, with functions such as catabolism, toxin clearance, and antioxidation. However, the liver is easily damaged by various pathogenic factors both inside and outside the body. As a common clinical disease, liver disease has always been a focus of global medical attention and research, and acute liver injury is the starting point of almost all liver diseases. The use of CCL4 to establish an acute liver injury rat model in this experiment is one of the classic modeling methods. CCL4 is injected intraperitoneally into the animal body and can directly enter liver cells. Through the biotransformation of liver cytochrome P450, images and CCl3O2 free radicals are generated in the body. The images freely bind with intracellular macromolecules, leading to the destruction of liver cell membrane structure and function, ultimately causing liver cell degeneration and necrosis. After liver cells are damaged, a large amount of AST and ALT will enter the bloodstream, leading to a significant increase in serum AST and ALT levels. GSH Px and SOD can clear peroxides and free radicals produced by cellular metabolism in the body, alleviate liver tissue damage, and protect liver cells. IL-1 β, IL-6, and TNF – α are all important pro-inflammatory factors in acute liver injury. IL-1 β can stimulate the production of inflammatory neurotransmitters and cytokines through its own secretion. IL-6 is a lymphokine produced by T cells and fibroblasts, and can serve as the main regulatory mediator of inflammatory response. TNF – α is mainly produced by NK cells, macrophages, and T cells, and has immune regulatory function and participates in inflammatory response. TNF – α and IL-1 β can induce the production of IL-6 inflammatory factors, forming a cascade amplification effect of inflammation, ultimately exacerbating liver injury. The results of this experimental study indicate that cabbagein can reduce the levels of ALT, AST, and MDA in the serum of rats with acute liver injury induced by CCl4, increase the activity of SOD and GSH Px, and reduce the content of TNF – α, IL-6, and IL-1 β in liver tissue. This suggests that cabbagein has an improving effect on CCl4 induced acute liver injury, which may be related to antioxidant stress and inhibition of inflammatory response.

Research has shown that the JAK-STAT signaling pathway is a recently discovered signaling pathway that regulates immune and inflammatory responses by participating in signal transduction of various growth factors and cytokines. IL-6 is a multifunctional cytokine that regulates immune and inflammatory responses. The activation of the IL-6/JAK2/STAT3 signaling pathway involves the recognition and binding of IL-6 to its target cell surface receptor sIL-6R, forming a complex called sIL-6R/IL-6. The activation of membrane glycoprotein 130 (gp-130) activates the associated JAK2, which then binds to downstream effector signaling and transcription factor 3 (STAT3) for phosphorylation. Phosphorylated STAT3 activates nuclear transcription factor NF – κ B, which is then activated and transferred to the nucleus, promoting the release of inflammatory factors such as TNF – α, IL-6, IL-1 β, etc. When these inflammatory factors are overexpressed, they can positively feedback to NF – κ B, thereby promoting inflammatory response and exacerbating liver tissue damage. In addition, activation of the IL-6/JAK2/STAT3 pathway can promote the differentiation of B cells into plasma cells and stimulate the autocrine secretion of IL-6, thereby forming a positive feedforward loop, which can also lead to further expansion of the inflammatory response. The results of this study showed that compared with the normal group, the expression of IL-6, p-JAK2, p-STAT3, and p-NF – κ B p65 was significantly increased in the model group, suggesting that this inflammatory signaling pathway may be activated; After treatment with insulin, the liver function indicators ALT, AST, MDA, SOD, and GSH Px in the serum tended to be normal, while the expression of IL-6, p-JAK2, p-STAT3, and p-NF – κ B p65 decreased to varying degrees. Pathological sections showed significant improvement in hepatocyte degeneration, necrosis, and inflammatory cell infiltration in the portal area and central vein of the liver tissue. Immunohistochemistry showed a significant decrease in IL-6 expression to varying degrees, suggesting that insulin may intervene in IL-6 expression to inhibit the activation of the IL-6/JAK2/STAT3 signaling pathway, reduce the release of inflammatory factors, reduce inflammation and apoptosis, and effectively improve liver injury.

In summary, cabbagein can effectively alleviate CCl4 induced acute liver injury in rats, and its mechanism may be related to the inflammatory response and antioxidant mediated by the IL-6/JAK2/STAT signaling pathway. The results of this study can provide new ideas for the clinical use of cabbagein the treatment of acute liver injury.