Emodin and baicalein inhibit pancreatic stromal derived factor-1 expression in rats with acute pancreatitis

Background: Stromal derived factor-1 (SDF-1) is an efficacious leukocyte chemoattractant, which can attract lymphocytes and mononuclear cells from bloodstream into the site of inflammation. Emodin, an anthraquinone derivative from Radix et Rhizoma Rhei, and baicalein, a flavone from Scutellaria baicalensis Georgi, both have been reported to possess anti-inflammatory activities. The expression pattern of SDF-1 in experimental acute pancreatitis (AP) and the effect of emodin or baicalein on that are not well defined. The present study aimed to investigate the effects of emodin and baicalein on pancreatic myeloperoxidase (MPO) activity (reflecting leukocyte sequestration) and cytokine production, as well as tissue SDF-1 expression in the setting of AP. Methods: A rat model of AP was induced by administration of 5% sodium taurocholate through the biliopancreatic duct. The level of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and MPO in the pancreas, and serum amylase were tested by immunohistochemistry, ELISA and chromatometry. The expressions of SDF-1α and SDF-1β were detected by real-time PCR, Western blotting, and immunohistochemistry. Result: Combination of emodin and baicalein significantly reduced pancreatic TNF-α, IL-6 and MPO, and also inhibited pancreatic SDF-1 expression. Conclusions: The inhibition of SDF-1 expression by emodin and baicalein might contribute, in part at least, to the amelioration of pancreatic inflammation. The present study also shows benefits of simultaneous treatment of AP.