morin and Mastitis

Mastitis is a common veterinary clinical disease that restricts the development of dairy farming around the world. Morin, extracted from Mulberry Tree and other herbs, has been reported to possess the function of anti-bacteria, anti-oxidant, and anti-inflammatory. However, whether morin could protect lipopolysaccharide (LPS)-induced mouse mastitis in vivo has not well known. This study firstly aims to evaluate the effects of morin on LPS-induced mouse mastitis in vivo, and then try to illustrate the mechanism involved in the process. Before injected with LPS, mice were intraperitoneally pre-injected with different concentrations of morin, and mice of the control and LPS group were injected with the same amount of saline. Pathologic changes of mammary gland were determined by histopathological examination. Myeloperoxidase (MPO) activities of mammary gland were determined by the MPO kits. The mRNA expressions of inflammatory cytokines including TNF-α, IL-1β and IL-6, and those of chemokine factors CCL2 and CXCL2, and those of tight junctions occludin claudin-3 were examined by qRT-PCR analysis. The activities of IκB, p65, ERK, P38, AKT, PI3K, NLPR3, claudin-1, claudin-3 and occludin were determined by western blotting. The results showed that morin alleviated LPS-induced edema, destructed structures and infiltrated inflammatory cells of mammary gland. Morin administration significantly decreased LPS-induced TNF-α, IL-1β, IL-6, CCL2 and CXCL2 mRNA expressions. Furthermore, western blot analysis also showed that morin significantly reduced LPS-induced phosphorylation of p65, IκB, p38 and ERK, and enhanced LPS-induced phosphorylation of AKT and PI3K. It was also found that LPS-decreased claudin-3 and occludin expressions were also inhibited by morin treatment. In summary, above results suggest that morin indeed protect LPS-induced mouse mastitis in vivo, and the mechanism was through inhibiting the PI3K/AKT, MAPK, NF-κB and NLRP3 signaling pathways and protecting the integrity of blood-milk barrier by regulating the tight junction proteins expressions.

Topics: Animals; Anti-Inflammatory Agents; Cytokines; Female; Flavonoids; Lipopolysaccharides; Male; Mammary Glands, Animal; MAP Kinase Signaling System; Mastitis; Mice, Inbred BALB C; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt

Mastitis is one of the most common diseases that both affects human and animals. Morin is derived from the member of Moraceae family, which has been used in the treatment of many inflammatory diseases. The purpose of this study was to test the protective effect of morin on LPS-induced mastitis and to clarify the possible mechanism. In vivo, the mastitis model was established by lipopolysaccharide (LPS), and morin was treated 1 h before stimulation of LPS. In vitro, peritoneal macrophages were used to test the regulation mechanisms of morin on mastitis. The inflammatory cytokines (TNF-α, IL-1β, and IL-6) was tested by ELISA. Myeloperoxidase (MPO) activity was measured by MPO kit. The expression of NLRP3 inflammasome and NF-κB signaling pathway proteins were detected by western blotting. The results showed that morin alleviated the pathological damage of mammary gland tissues, MPO activity, and the production of TNF-α, IL-1β, and IL-6 in mammary gland tissues. In vitro, morin significantly suppressed the production of inflammatory cytokines. In addition, it also inhibited the activation of NLRP3 inflammasome and NF-κB signaling pathway induced by LPS. In conclusion, the present study suggested that the protective effect of morin against LPS-induced mastitis may be due to its ability to inhibit NLRP3 inflammasome expression and NF-κB signaling pathway.

Topics: Animals; Antioxidants; Cell Survival; Dose-Response Relationship, Drug; Female; Flavonoids; Lipopolysaccharides; Mastitis; Mice; Mice, Inbred BALB C; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Signal Transduction