Naoxintong attenuates Ischaemia/reperfusion Injury through inhibiting NLRP 3 inflammasome activation

Abstract Naoxintong ( NXT ) is a Chinese Materia Medica standardized product extracted from 16 various kinds of Chinese traditional herbal medicines including Salvia miltiorrhiza , Angelica sinensis , Astragali Radix. Naoxintong is clinically effective in treating ischaemia heart disease. Nucleotide‐binding oligomerization domain‐Like Receptor with a Pyrin domain 3 ( NLRP 3) inflammasome has been critically involved in myocardial ischaemia/reperfusion (I/R) injury. Here, we have been suggested that NXT might attenuate myocardial I/R injury via suppression of NLRP 3 inflammasome activation. Male C57 BL 6 mice were subjected to myocardial I/R injury via 45 min. coronary ligation and release for the indicated times. Naoxintong (0.7 g/kg/day) and PBS were orally administrated for 2 weeks before surgery. Cardiac function assessed by echocardiography was significantly improved in the NXT group compared to PBS group at day 2 after myocardial I/R. NLRP 3 inflammasome activation is crucially involved in the initial inflammatory response after myocardial I/R injury, leading to cleaved caspase‐1, mature interleukin ( IL )‐1β production, accompanying by macrophage and neutrophil infiltration. The cardioprotective effect of NXT was associated with a diminished NLRP 3 inflammasome activation, decreased pro‐inflammatory macrophage (M1 macrophages) and neutrophil infiltration after myocardial I/R injury. In addition, serum levels of IL ‐1β, indicators of NLRP 3 inflammasome activation, were also significantly suppressed in the NXT treated group after I/R injury. Naoxintong exerts cardioprotive effects at least partly by suppression of NLRP 3 inflammasome activation in this I/R injury model.