Sodium houttuyfonate inhibits LPS-induced mastitis in mice via the NF-B signalling pathway

Sodium houttuyfonate (SH) has been indicated to play an important anti-inflammatory role. Previous studies have confirmed that SH can inhibit the NF-B pathway in lipopolysaccharide (LPS)-induced mastitis in bovine mammary epithelial cells. However, the effects of SH on LPS-induced mastitis in animals should be verified to further evaluate its actual value. In the present study, the anti-inflammatory effects of SH were investigated in mouse models and a mouse mammary epithelial cell line. Hematoxylin and eosin staining (H&E) showed that SH therapy significantly alleviated the pathological changes in mammary glands. Myeloperoxidase (MPO) activity analysis demonstrated that SH substantially decreased MPO activity in vivo. RT-qPCR results showed that SH reduced the expression of interleukin (IL)-1, IL-6 and tumor necrosis factor both in vivo and in vitro. In addition, western blot results indicated that SH suppressed the phosphorylation of nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-B) p65 protein and reduced the degradation of inhibitor of kappa light polypeptide gene enhancer in B-cells alpha protein in vivo and in vitro. These results demonstrated that SH ameliorates LPS-induced mastitis by inhibiting the NF-B pathway.