Study On The Mechanism Of Panax Notoginseng Resisting Liver Fibrosis Induced By Naltrexone

Hepatic fibrosis is the pathological changes of chronic liver injury caused by many reasons. It is characterized by the liver extracellular matrix (extracellulaur matrix, ECM) excessive accumulation, impact physiological function of liver. The etiology of liver fibrosis is very complex, chronic liver disease caused by various pathogenic factors which can develop into liver fibrosis, such as liver inflammation, oxidative stress, apoptosis of liver cells, and hepatic stellate cells (hepatic stellate cell, HSC) activation. The treatment effect of liver fibrosis is not well, thus it has become more and more common and has attracted extensive attention.Naltrexone (Naltrexone, NTX) is a compound of oxymorphone N-cyclopropyl methyl derivatives of opioid receptor antagonist, is exogenous opioid receptor antagonist, it binding opioid activity is far greater than morphine and enkephalin,3 kinds of opioid receptors (mu-, Delta, kappa) have antagonistic effect, it can competitively block and replace the binding of morphine like substance and receptor and clear morphine poisoning signs. Naltrexone can play a barrier between opioid receptor and drugs, has been used for the treatment of alcohol and morphine dependence. Naltrexone has no addcition effect, however, long-term use can cause liver pathological change, it will cause liver damage, liver fibrosis, can lead to cirrhosis and liver cancer in severe cases.Panax is a kind of Chinese traditional medicine, Panax saponins (PTS) are the main bioactive components in Panax, with promoting blood circulation to remove blood stasis, resisting oxidation, inhibiting intracellular inflow of Ca2+ effect. In the regulation of liver function, Panax can improve liver microcirculation, regulate blood sugar, decrease blood cholesterol and blood lipids, scavenge free radical, protect mitochondria, endoplasmic reticulum, the inhibit of type Ⅰ collagen, type Ⅲ collagen and transforming growth factor 1 (transforming growth factor-beta 1, TGF-β1) in the liver, it plays an important role in resisting hepatic fibrosis and even liver cancer etc.Matrix metalloproteinases (matrix metalloproteinases, MMPs) are a large family, MMPs need to bind Ca2+, Zn2+ and other metal ions when it plays in organisms. MMPs can almost degrade extracellular matrix (extracellular matrixc, ECM) of various proteins in the liver. MMPs are closely related decomposition of collagen. In addition, MMPs play a key role in the barrier of the destruction of tumor cell invasion of the organization, in tumor invasion and transfer. In the MMPs family, MMP-2 is the most widely distributed enzyme.Thioredoxin-1 (Trx-1) is a widely expressed in various biological tissues and cells, low molecule weight protein, plays an important role in regulating the redox reaction. At the same time, it also has the biological functions such as transcription regulation, resisting apoptosis and regulating inflammation.By using the morphine receptor antagonist naltrexone (Naltrexone, NTX) to treat human hepatocellular carcinoma cells (Human Hepatoma Cell Line, HepG2) and C57BL/6 mice, to construct cell model and animal model of liver fibrosis in chronic liver injury, to study the molecular mechanism of liver injury induced by naltrexone, as well as Panax’s biological role in resisting naltrexone induced liver injury and liver fibrosis. To study further molecular mechanism of PTS preventing and treating liver fibrosis by inducing thioredoxin-1 expression.The main results:NTX decreased the viability of HepG2 cells in dose dependent manner, at the same time, HepG2 cells also significantly changed in the morphology. The expressions of Pro-caspase-9, Pro-caspase-3, Bcl-2 related to apoptosis were decreased, the expressions of Bax and Cytochrome c (Cyt c) were increased. In this process, the expression of Trx-1 was decreased. After PTS was added, the cell viability of HepG2 was stored, and the decreases of Pro-caspase-9, Pro-caspase-3 and Trx-1 were suppressed, too. In mice experiment, we selected 6-8 weeks male C57BL/6 mice and randomly divided these mice into 4 groups, respectively for the control group, naltrexone group, Panax + naltrexone group and the PTS group,10 mice in each group, the control group were filled with saline, naltrexone group was gavaged with naltrexone, PTS+naltrexone group in the abdominal cavity irrigation stomach naltrexone and injecting PTS, intraperitoneal injection of PTS of the PTS groups. After three months of continuous treatment, blood and liver tissue were collected. The results showed that the levels of alanine aminotransferase (ALT) and aspertate, aminotransferase (AST) in naltrexone group were significantly higher than those in the control group, while the contents of ALT and AST in PTS+naltrexone group were less than the group of naltrexone; similarly, liver tissue of HE staining results showed that naltrexone group of mice liver tissue had obvious necrosis, and PTS+naltrexone group was not. At the same time, in the liver of naltrexone group, the expressions of matrix metalloproteinase 2 (MMP-2), transforming growth factor 1 (TGF-beta 1), cell cycle protein D1 (cyclin D1) related to the occurrence and development of hepatic fibrosiswere increased by Western blot. However, the expression of Trx-1 was decreased. Treatment with PTS reversed these alterations of expressions. Therefore, the PTS could effectively resist chronic liver injury and hepatic fibrosis induced by naltrexone through inducing Trx-1 expression.Conclusion:Trx-1 plays an important role in PTS resisting liver damage and liver fibrosis induced by naltrexone. Trx-1 is expected to become an important target for treating chronic liver injury and liver fibrosis.