Quyu Xiaozhong recipe exerts anti-inflammatory effect in acute mastitis by inhibiting TLR4/NF-κB signal pathway

Abstract

Purpose: To investigate the effect of Quyu Xiaozhong recipe (QYXZR) on acute mastitis induced by Staphylococcus aureus in rats via TLR4/NF-κB signal pathway. Methods: The rat model of acute mastitis was constructed by injecting Staphylococcus aureus into the fourth pair of nipples of rats 5-7 days after  parturition. The rats were treated with drugs 12 h after injection. Pathological changes in rat mammary tissue were determined using hematoxylin-eosin  (H&E) staining. Myeloperoxidase (MPO) kit was used to evaluate MPO activity. Enzyme-linked immunosorbent assay (ELISA) was employed to determine  the levels of inflammatory factors, while changes in protein expression of TLR4, NF-κB-p65, and IκB-α were determined by Western blot. Results: QYXZR  intervention significantly attenuated pathological damage in rats and alleviated Staphylococcus aureus-induced mastitis. At the same time, QYXZR  significantly reduced the expression of MPO and the levels of inflammatory factors (p < 0.05). Further molecular mechanistic studies revealed that QYXZR  exerted anti-inflammatory effects by inhibiting TLR4/NF-κB signal pathway. Conclusion: QYXZR alleviates acute mastitis caused by Staphylococcus aureus  via the inhibition of TLR4/NF-κB pathway, thus, providing the scientific and theoretical basis for the extensive use of this traditional Chinese medicine in  the treatment of acute mastitis.