TLR4 and myocardial infarction: As predicted, we found that the activation of TLR4 and NF-κB (p-65) in MI was inhibited by melatonin both in vivo and in vitro, whereas administration of LPS, an agonist of the TLR4/NF-κB signaling pathway, abrogated the beneficial effect of melatonin on cardiac pyroptosis.