Salidroside attenuates inflammatory responses by suppressing nuclear factor-κB and mitogen activated protein kinases activation in lipopolysaccharide-induced mastitis in mice

Mastitis is defined as inflammation of the mammary gland in domestic dairy animals and humans. Salidroside, a major component isolated from Rhodiola rosea L., has potent anti-inflammatory properties, but whether it can be used in mastitis treatment has not yet been investigated. The aim of this study was to assess the protective effects of salidroside against lipopolysaccharide (LPS)-induced mastitis in mice and the mechanism of action. We used a mouse mastitis model in which mammary gland inflammation was induced by LPS challenge. Salidroside administered 1 h before LPS infusion significantly attenuated inflammatory cell infiltration, reduced the activity of myeloperoxidase in mammary tissue, and decreased the concentration of tumor necrosis factor-alpha, interleukin (IL)-1 beta, and IL-6 in a dose-dependent manner. Further studies revealed that salidroside down-regulated phosphorylation of LPS-induced nuclear transcription factor-kappaB (NF-kappa B) p65 and inhibitor of NF-kappa B alpha (I kappa B alpha) in the NF-kappa B signal pathway, and suppressed phosphorylation of p38, extracellular signal-regulated kinase (ERK) and c-jun NH2-terminal kinase (JNK) in MAPKs signal pathways. This study demonstrates that salidroside is an effective suppressor of inflammation and may be a candidate for the prophylaxis of mastitis.