| Daphnetin is a effective monomeric compound extracted from the plants of Dracaena marginata (D.marginata).It is a new drug, first made in China, and its scientific name is7,8-dithydroxycoumarin.It was reported that by intragastric administration or intraperitoneal injection, Daphnetin can suppress foot-plate swelling caused by egg white and dextranum, the inhibiting effect is similar to the effect of salicylic acid.The effect of anti-inflammatory of Zushima injection, of which the main components is Daphnetin, was studied and found that Zushima injection can obviously suppress the acute exudative inflammation in rats and the effect was even better than that of the hydrocortisone at the same dose.Foreign scholars also studied the suppression effect of the17extracts from plants of D. marginata on the TNF-a, IL-1in vitro. It was found that Daphnetin had the significant role on the suppression of inflammatory cytokine.It was demonstrated that Daphnetin had the effect of anti-platelet aggregation and can also suppressed oxidative hemolysis and respiratory burst of PMN.It may suppress the activity of Cyclooxygenase and5-ester oxidase. Daphnetin may have the anti-inflammatory and antiallergic effect by suppressing the synthesis of prostaglandins and leukotriene.Daphnetin can suppress protein kinase and has the effect on the immune regulatory function.In addition, it was showed that Daphnetin had antibacterial effect.The recent studies showed that Daphnetin can block and suppress the development of the adjuvants induced arthritis and autoimmune arthritis, indicating that Daphnetin was one effective component in treating arthritis. Daphnetin is a compound from Chinese herbal medicine and has a comprehensive pharmacological effect. So far, Daphnetin is used to treat several types of diseases,such as arthritis, thromboangiitis obliterans, coronary heart disease and other diseases. However there is no report whether Daphnetin can suppress the inflammatory diffusion, improve pancreatic damage or not.This study is divided into two parts to explore the effect and the mechanism of Daphnetin on severe acute pancreatitis in rats. First, we estimated the effect of Daphnetin on severe acute pancreatitis. Second, we studied the molecular mechanism of Daphnetin on the anti-inflammation, which will provide the theoretical foundation for the use of Daphnetin in severe acute pancreatitis. Part1Protective effects of daphnetin on sodium taurocholate-induced severe acute pancreatitis in ratsObjective:Severe acute pancreatitis (SAP) is the sudden onset of inflammation in the pancreas with high mortality, which is characterized by edema, acinar cell necrosis, hemorrhage, and severe inflammation of the pancreas. Daphnetin has been shown to alleviate organ injury in a variety of preclinical animal models of coagulation disorders. The aim of this study was to investigate the protective effects of daphnetin on severe acute pancreatitis in rat model.Methods:Severe acute pancreatitis rat model was induced by retrograde infusion of5%sodium taurocholate (1m1/kg) into the bile-pancreatic duct. Daphnetin (4mg/kg) was administered intraperitoneally at30min prior to the infusion of sodium taurocholate. The severity of pancreatitis was evaluated by various analyses of serum amylase and lipase level, tumor necrosis factor-a and interleukin-1? level, myeloperoxidase (MPO) activity and malondialdehyde (MDA) content, and histopathology grading. The levels of TNF-a and IL-1? in the serum were also measured by ELISA.Results:The results showed that daphnetin-treated SAP rat group (SAP-D) exhibited lower pathological score of pancreas compared to SAP group (SAP)(p<0.05). Further analyses demonstrated that SAP-D group had lower levels of serum amylase and lipase (p<0.05), and proinflammatory cytokines including TNF-? and IL-1?(p<0.05), and decreased MPO activity and MDA content (p<0.05) in3h,6h,12h after the infusion of sodium taurocholate compared with SAP group (SAP).Conclusion:These findings indicated that daphnetin could exert protective function in SAP rat model. Therefore, daphnetin may be considered as a potential compound for the therapy and prevention in acute pancreatitis. Part2The effect of daphnetin on TLR4/NF-?B signaling pathway in severe acute pancreatitis induced by sodium taurocholate in ratsSevere acute pancreatitis (SAP) is the sudden onset of inflammation of the pancreas, often results in subsequent multiple-organ dysfunction syndrome with high mortality. Daphnetin, a coumarin extracted from Daphne odora, has been reported to possess properties of analgesic and anti-inflammatory effects.Objective: The objective of this study was to investigate the potential mechanism of daphnetin on severe acute pancreatitis induced by sodium taurocholate in rats.Methods: Female Wistar rats were pretreated with daphnetin30min before retrograde infusion of5%Sodium Taurocholate (1mL/kg) into the bile-pancreatic duct. Daphnetin (4mg/kg) was administered intraperitoneally. Twelve hours after sodium taurocholate administration,histological analysis,serum amylase and lipase levels was evaluated.The myeloperoxidase (MPO) activity and malondialdehyde (MDA) content in pancreatitis tissues were determined. The levels of tumor necrosis factor-a (TNF-a), interleukin-6(IL-6) and interleukin-1? (IL-1?) in the serum were measured by enzyme-linked immunosorbent assay (ELISA). The levels of phosphorylation of nuclear factor of inhibitory kappa B alpha (I?B?), and Toll-like receptor-4(TLR4) expression were detected by western blot analysis. DNA-binding activity of nuclear factor kappa-B (NF-?B) was assessed,which was used as an index of NF-?B activation by electrophoretic mobility shift assay (EMSA).Results:We found:1) daphnetin markedly attenuated the histological alterations (p<0.05) in the pancreatitis;2) daphnetin remarktable reduced levels of serum amylase and lipase (p<0.05);3)daphnetin obviously decreased MPO activity and MDA content (p<0.05) in pancreatitis tissues;4) daphnetin significantly down-regulated the levels of pro-inflammatory mediators, including TNF-a, IL-1? and IL-6(p<0.05);5) daphnetin could inhibite the phosphorylation of I?B?, NF-?B activation and the expression of TLR4(p<0.05).Conclusion: Our results suggest that anti-inflammatory role of daphnetin against severe acute pancreatitis may be through inhibiting TLR4mediated NF-?B signaling pathway. Daphnetin may be a promising therapeutic reagent for the treating severe acute pancreatitis. |
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