Baicalein attenuates inflammatory responses by suppressing TLR4 mediated NF-κB and MAPK signaling pathways in LPS-induced mastitis in mice

Baicalein is a phenolic flavonoid presented in the dry roots of Scutellaria baicalensis Georgi. It has been reported that baicalein possesses a number of biological properties, such 8 antiviral, antioxidative, anti-inflammatory, antithrombotic, and anticancer properties. However, the effect of baicalein on mastitis has not yet been reported. This research aims to detect the effect of baicalein on lipopolysaccharide (LPS)-induced mastitis in mice and to investigate the molecular mechanisms. Baicalein was administered intraperitoneally 1 h before and 12 h after LPS treatment. The results indicated that baicalein treatment markedly attenuated the damage of the mammary gland induced by LPS, suppressed the activity of myeloperoxidase (MPO) and the levels of tumor necrosis factor (TNF-alpha) and interleukin (IL-1 beta) in mice with LPS-induced mastitis. Besides, baicalein blocked the expression of Toll-like receptor 4 (TLR4) and then suppressed the phosphorylation of nuclear transcription factor-kappaB (NF-kappa B) p65 and degradation inhibitor of NF-kappa B alpha (I kappa B alpha) and, and inhibited the phosphowlation of p38, extracellular signal-regulated kinase (ERIC) and c-jun NH2-terminal kinase (JNK) in mitogen-activated protein kinase (MAPK) signal pathway. These findings suggested that baicalein may have a potential prospect against mastitis. (C) 2015 Elsevier B.V. All rights reserved.