Melatonin Induces Anti-Inflammatory Effects to Play a Protective Role via Endoplasmic Reticulum Stress in Acute Pancreatitis

Background/Aims: Melatonin, which is mainly secreted by the pineal gland and released into blood, has anti-inflammatory properties in acute pancreatitis. Many studies show that melatonin can relieve inflammation in taurocholate-induced acute pancreatitis. However, the mechanisms of its anti-inflammatory effects are still undefined, especially the relationship between melatonin and endoplasmic reticulum stress. We explored the anti-inflammatory activity of melatonin in AR42J and rat models. Methods: The CCK-8 assay was used to assess effects of melatonin on AR42J cell viability. Inflammatory degree and the expressions of endoplasmic reticulum stress related molecules were examined by quantitative RT-PCR and western blotting. The degree of inflammation in the tissue was also accessed by pathological grading. Finally, we used the western blotting method to verify apoptosis and autophagy. Results: Endoplasmic reticulum stress was obviously activated in early stage inflammation in AR42J and rat models. Melatonin could induce anti-inflammatory effects via endoplasmic reticulum stress. Melatonin significantly inhibited inflammatory cytokines and the expression of ERS-related molecules. Finally, it played a protective role by promoting apoptosis and autophagy of the cells, which were damaged in the process of inflammatory reaction. Conclusion: Melatonin induces anti-inflammatory effects via endoplasmic reticulum stress in acute pancreatitis to play a protective role. (C) 2016 The Author(s) Published by S. Karger AG, Basel