ABSTRACT
ObjectiveTo investigate the effect and mechanism of echinacoside （ECH） in improving liver injury in rats with acute pancreatitis by establishing a rat model of acute pancreatitis and liver injury. MethodsA total of 24 Sprague-Dawley rats were randomly divided into blank group （Con group）， control group （Con+ECH group）， acute pancreatitis group （AP group）， and acute pancreatitis+ECH intervention （AP+ECH group）. The rats were given intraperitoneal injection of 10 mg/kg ECH on day 7 before the establishment of the model of acute pancreatitis； at 24 hours after the last administration of cerulein， blood samples were collected via the abdominal aorta， and serum was separated for biochemical analysis including alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， lactate dehydrogenase （LDH）， gamma-glutamyl transpeptidase （GGT）， alkaline phosphatase （ALP）， albumin （Alb）， total bilirubin （TBil）， cholinesterase， blood amylase （Amy）， and lipase （LPS）. HE staining was used to observe the histopathological changes of the pancreas and the liver； transmission electron microscopy （TEM） was used to observe the microstructural changes of pancreas and liver tissue； ELISA was used to measure the levels of interleukin-1β （IL-1β）， interleukin-16 （IL-6）， tumor necrosis factor-α （TNF-α）， and interleukin-10 （IL-10） in liver tissue homogenate； immunohistochemistry was used to measure the levels of TNF-α and p-p65 NF-κB in pancreas and liver tissue； Western blot was used to measure the expression levels of NF-κB pathway proteins in liver tissue. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the SNK test or the Dunnett’s T3 method was used for further comparison between two groups. ResultsCompared with the Con group， the AP group had significant increases in ALT， AST， GGT， LDH， ALP， TBil， Amy， and LPS （all P<0.01）， as well as significant increases in the levels of IL-1β， IL-6， IL-10， and TNF-α in liver tissue homogenate （all P<0.01）. ECH intervention reduced the levels of ALT， AST， GGT， LDH， ALP， TBil， AMY， and LPS and inhibited the secretion of IL-1β， IL-6， and TNF-α in rats with acute pancreatitis. HE staining showed that ECH intervention alleviated the vacuolar degeneration of acinar cells， inflammatory cell infiltration in pancreatic tissue， and the necrosis of hepatocytes compared with the AP group. TEM showed that compared with the AP group， there was a reduction in the degree of mitochondrial swelling in liver and pancreatic cells after ECH intervention. ECH intervention partially reversed the elevated expression levels of p-p65 NF-κB and TNF-α in liver and pancreatic tissue. In addition， the expression levels of MyD88， p-IκBα， p-IKKα， and p-p65 were upregulated in liver tissue of rats with acute pancreatitis， which could be partially reversed after ECH intervention. ConclusionEchinacoside can alleviate liver and pancreatic injury induced by acute pancreatitis by inhibiting the TLR4/MyD88/NF-κB pathway.
ABSTRACT
BACKGROUND: Liver injury in a multiple organ failure model causes great troubles to clinicians’ medication. Thymosin α1 is used for treating chronic hepatitis and it has obvious protective effects against liver injury. OBJECTIVE: To investigate the protective mechanism of thymosin α1 on liver injury in a rat model of multiple organ failure, based on adiponectin (ADPN)/ protein kinase B (Akt)/nuclear factor κB (NF-κB) signaling pathway. METHODS: Male SPF Sprague-Dawley rats were randomly divided into four groups: normal group, model group, experimental group, and control group. Rats in the model group, experimental group, and control group were given intraperitoneal injection of 500 mg/kg zymosan (50 g/L) to construct the rat multiple organ failure model. Normal rats were injected intraperitoneally with equal doses of normal saline. Thirty minutes after the injection, the rats in the experimental group and the control group were injected intraperitoneally with 2 mL of thymosin α1 and ganlixin with the dose of 0.5 mg/kg daily, respectively. The normal group and the model group were injected intraperitoneally with the same dose of normal saline. After 7 days of continuous administration, liver function parameters were tested; histopathological changes of rat liver tissues and cell apoptosis were detected using hematoxylin-eosin staining and TUNEL staining; immunohistochemistry and western blot were used to detect the expression of interleukin-10, tumor necrosis factor α (TNF-α), adiponectin (ADPN), adiponectin recepror 2, AdipoR2, p-AKT and NF-κB. RESULTS AND CONCLUSION: Compared with the normal group, the levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin in the serum, the pathological scores of liver injury, the cell apoptotic rate, and the expression levek of TNF-α and NF-κB were significantly increased in the model group, while the serum levels of total protein, interleukin-10, ADPN, AdipoR2 and p-AKT were significantly reduced in the model group (all P < 0.05). Compared with the model group, the serum levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, the pathological scores of liver injury, and cell apoptotic rate in the experimental group and control group were significantly reduced, and the serum levels of total protein, interleukin-10, ADPN, AdipoR2 and p-AKT were significantly increased (all P < 0.05). To conclude, thymosin α1 has a protective effect on the liver of rats with multiple organ failure induced by zymosan. The mechanism is related to the ADPN/Akt/NF-κB signaling pathway. ADPN/Akt is activated and the activation of NF-κB is inhibited, then reducing the inflammatory response.