Leonurine ameliorates the inflammatory responses in lipopolysaccharide-induced endometritis

Endometritis is the inflammation of the endometrium that is associated with lower conception rates, increased intervals from calving to first service, and more culls for failure to conceive, which leads to serious economic losses in the dairy industry. Leonurine, a natural active compound of Leonurus cardiaca, has been proved to possess various biological activities. However, there is still no study about its anti-inflammatory effects on LPS-induced endometritis. The present study aimed to demonstrate the underlying mechanism responsible for the anti-inflammatory effects of leonurine on LPS induced endometritis in mice and in bovine endometrial epithelial cells (bEECs). The results of pathological section displayed that leonurine alleviated LPS induced uterine injury. qRT-PCR and ELISA experiments suggested that leonurine inhibited the expression levels of TNF-α and IL-1β in uterus tissues and bEECs. Molecular studies showed that TLR4 expression and nuclear factor (NF)-κB activation were both inhibited by leonurine treatment. These results suggested that the therapeutic effects of leonurine on LPS-induced endometritis in mice and bEECs may act by inhibiting the expression of TLR4 and its downstream mediated NF-κB pathway. Accordingly, leonurine may serve as an effective drug in preventing and treating LPS induced endometritis.