Jingfang Granules alleviate LPS-induced mastitis by inhibiting inflammation, protecting the blood-milk barrier structure and regulating cell apoptosis

Mastitis is the most common malignant disease in women, which seriously threatens women's physical and mental health. Jingfang Granules (JF) is a Chinese medicine compound, derived from the classic famous prescription-''Jingfang Baidu Powder''. JF has been widely used to relieve symptoms such as fever, headache, and cough caused by a cold. Our previous studies have shown that JF contains various active ingredients (β-sitosterol, isorhamnetin, hesperetin), which has the effect on antibacterial, anti-inflammatory and anti-apoptotic. Previous studies conveyed that JF had the potential to treat metabolic abnormalities and inflammation, which promoted us to investigate its therapeutic effects on LPS-induced mastitis and the underlying mechanisms. The pathologic changes suggested that the mammary gland edema and inflammatory factor infiltration were alleviated by JF in LPS-induced mastitis model. Furthermore, The ELISA assays suggested that the activity of Myeloperoxidase (MPO) and the expression of pro-inflammatory factors such as IL-1β, IL-6 and TNF-α were reduced by JF. The protein levels of TLR4, P-NF-κB, NLRP3, ASC, Caspase-1, IL-1β, P-P38, P-ERK1/2, and P-AKT were detected by western blotting. And then we found that JF alleviated mastitis inflammation by regulating NF-κB, NLRP3, PI3K/AKT, MAPK signaling pathways. In addition, we found that JF improved the integrity of the blood-milk barrier by increasing the expression of ZO-1, Claudin-3 and Occludin. Interestingly, JF could also significantly inhibit LPS-induced apoptosis. In summary, we successfully established a model of LPS-induced mastitis in mice and confirmed that JF could inhibit inflammation, improve the integrity of the blood-milk barrier and inhibit apoptosis, which also indicates the potential applicability of JF for the prevention and treatment of mastitis.