Resveratrol inhibits NLRP3 inflammasome activation to alleviate bovine mastitis by promoting PINK1-mediated mitophagy

OBJECTIVE: Negative energy balance in transition cows elevates the circulating concentrations of non-esterified fatty acids (NEFA), potentially leading to mastitis and posing a significant threat to the dairy industry. Resveratrol is a polyphenolic compound with anti-inflammatory properties, yet its role in NEFA-induced inflammation in bovine mammary epithelial cells (BMECs) remains unclear. This study aimed how resveratrol protects against mastitis and its underlying mechanisms. METHODS: BMECs were pre-treated with 100 μM resveratrol for 24 h, and then treated with 0.9 mM NEFAs for 4 h, and a PINK1 inhibitor was used to assess the mechanisms involved. Furthermore, a mouse model of mastitis was utilized to evaluate the hepatoprotective effects of resveratrol against mastitis in vivo. RESULTS: Resveratrol significantly attenuated the NEFA-induced inflammatory response, evidenced by reduced levels of NLRP3 inflammasome components (NLRP3, caspase1, IL-1β) and pro-inflammatory cytokines (IL-6, IL-1β and TNF-α). Mechanistically, resveratrol promoted mitophagy by upregulating levels of LC3-II, PINK1, and Parkin, while downregulating P62 expression. The anti-inflammatory effect of resveratrol was reversed when PINK1 was inhibited. In vivo experiments confirmed that resveratrol alleviated mammary gland inflammation and enhanced PINK1-mediated mitophagy. CONCLUSION: This study demonstrates that resveratrol mitigates NLRP3-mediated inflammation by activating PINK1-mediated mitophagy, suggesting its potential as a therapeutic option for mastitis in perinatal dairy cows with negative energy balance.