Investigating the Role of Salidroside in Alleviating Acute Pancreatitis by Inhibiting the RIPK1/RIPK3/MLKL Pathway-Mediated Necroptosis in Pancreatic Acinar Cells in Rats

Background: Necroptosis, a regulated form of cell death, is a key driver of pancreatic injury in acute pancreatitis (AP). Salidroside (Sal), a natural compound known for its antioxidant properties, was investigated for its potential to alleviate AP by targeting the necroptotic pathway.

Methods: An AP model was induced in Wistar rats via retrograde infusion of 3.5% sodium taurocholate into the pancreatic duct. Rats were randomly divided into three groups: sham, AP model, and AP + Sal (60 mg/kg). Serum levels of amylase (AMY) and inflammatory cytokines (IL-6, IL-1β, TNF-α) were measured, and pancreatic tissue damage was assessed. The involvement of the RIPK1/RIPK3/MLKL pathway and mitochondrial ultrastructure were analyzed by Western blot, immunohistochemistry (IHC), and transmission electron microscopy (TEM). An in vitro AP model was established in AR42J cells using cerulein (100 nM). Cells were pretreated with Sal or Necrostatin-1 (Nec-1), and mitochondrial membrane potential, necroptosis-related protein expression, and p-MLKL subcellular localization were examined.

Results: Sal treatment significantly reduced serum AMY levels (p < 0.01) and pro-inflammatory cytokines (IL-6, IL-1β, TNF-α; all p < 0.05) in AP rats. Histopathological analysis revealed that Sal markedly ameliorated pancreatic tissue edema, inflammatory infiltration, and necrosis (p < 0.01). Western blot analysis showed that Sal significantly inhibited the expression of key necroptosis-related proteins (RIPK1, RIPK3, and p-MLKL) in both pancreatic tissue and AR42J cells (all p < 0.05). IHC and immunofluorescence confirmed that Sal effectively suppressed p-MLKL membrane translocation (p < 0.01). TEM further demonstrated that Sal preserved mitochondrial structural integrity. However, in vitro, the combination of Sal and Nec-1 did not produce a significant additive effect.

Conclusion: Sal alleviates experimental AP by inhibiting Necroptosis, likely through targeting the RIPK1/RIPK3/MLKL pathway and preserving mitochondrial function. These findings suggest that Sal is a promising therapeutic candidate for AP treatment.

RIPK1/RIPK3/MLKL pathway; acute pancreatitis; mitochondrial dysfunction; necroptosis; salidroside.