Kaempferol‐3‐ O ‐rutinoside exerts cardioprotective effects through NF‐ κ B/NLRP3/Caspase‐1 pathway in ventricular remodeling after acute myocardial infarction

Ventricular remodeling (VR) after acute myocardial infarction (AMI) is the main pathogenesis of chronic heart failure (CHF). Kaempferol-3-O-rutinoside (KR) is the flavonoid glycoside with the highest content in Lu'an GuaPian tea, which has good pharmacological activities. However, the mechanism of KR against VR after AMI remains unclear. Molecular docking was used to predict the targets of KR on the NLRP3/Caspase-1 signaling pathway. Histological changes in the myocardium were visualized using HE staining, Masson staining. Cardiomyocyte apoptosis was detected using TUNEL. Immunohistochemistry was used to examine NLRP3, Caspase-1 p20, and GSDMD. IL-1β level in serum was detected using ELISA. Finally, the expressions of NF-κB p65, NLRP3, ASC, Caspase-1 p20, GSDMD, and IL-1β were measured using RT-PCR and Western blotting. Our results showed that KR had a good binding activity with NLRP3, Caspase-1, and GSDMD, significantly improved cardiac function, alleviated cardiac pathological changes, reduced the excessive deposition of myocardial interstitial collagen, and inhibited cardiomyocyte apoptosis in AMI rats. Furthermore, KR could decrease the IL-1β level and inhibit the expressions of NF-κB p65, NLRP3, ASC, Caspase-1 p20, GSDMD, and IL-1β. Our study suggests that KR can prevent and treat VR after AMI, and the protective effect is related to its regulatory NF-κB/NLRP3/Caspase-1 signaling pathway. PRACTICAL APPLICATIONS: Kaempferol-3-O-rutinoside is present in Carthamus tinctorius L., Nymphaea candida, Afgekia mahidoliae and green tea, which has good pharmacological activities against liver injury, cerebral ischemia/reperfusion injury, dementia, hyperglycemia, and myocardial infarction. Our previous study found that kaempferol-3-O-rutinoside had an obvious anti-inflammatory effect, and could significantly improve the cell survival rate of H9c2 myocardium inflammatory injury induced by LPS. In this study, kaempferol-3-O-rutinoside significantly improved cardiac function, alleviated cardiac pathological changes, reduced the excessive deposition of myocardial interstitial collagen, and inhibited cardiomyocyte apoptosis in AMI rats. Furthermore, kaempferol-3-O-rutinoside could decrease the IL-1β level and inhibit the expressions of NF-κB p65, NLRP3, ASC, Caspase-1, GSDMD and IL-1β, suggesting that kaempferol-3-O-rutinoside could regulate NF-κB/NLRP3/Caspase-1 signaling pathway.