Anti-inflammatory Activity And Its Molecular Mechanism Of Mulberry Fruit Extracts

Inflammation is a beneficial defense mechanism in body, caused by pathogenic bacteria, harmful stimulus or physical injury, but the abnormal inflammatory response would lead to the occurrence of various diseases. Therefore, inhibition of pro-inflammatory molecules become an important target for prevention or treatment of various diseases. For a long time, researchers trying to obtain the anti-inflammatory ingredients isolated from natural products, and obtained a large amount of research work. According to previous research, we found that mulberry has strong anti-inflammatory activity, in present study, we chosed mulberry fruit as the main experimental materials, identified its anti-inflammatory ingredients and studied its potential molecular mechanism.Firstly, five crude extracts of berries, including mulberry, blackberry, red raspberry, black rasberry and blueberry, were investigated for their inhibitory effect on NO induced by LPS in RAW264.7 macrophage cells. Then the effects of mulberry powder was evaluated on dextran sulfate sodium(DSS) induced mice acute colitis. Secondly, the anti-inflammatory activities of dichloromethane extracts(DCM), ethyl acetate extracts(EA), N-butanol extracts(BA), and water extracts(WE) from indigenous mulberries were evaluated on RAW264.7 macrophage cells. Thirdly, nuclear translocation of NF-kB p65 and anti-inflammatory mechanism were validated in the mice acute colitis model of MB-DCM. Finally, HPLC and column chromatography were performed to isolate monomer compounds of mulberry, their anti-inflammatory effects were evaluated based on the inhibition of NO in LPS-activated cell model.Our results showed that(1) Among five crude extracts, the anti-inflammatory effects of mulberry, blackberry and blueberry were stronger.(2) In LPS-activated RAW264.7 macrophages, the anti-inflammatory effect of DCMs was stronger than other three extracts from mulberry. The anti-inflammatory effect of DCM was confirmed, which was characterized as the reduction of the expression levels of inducible nitric oxide synthase(i NOS), cyclooxygenase-2(COX-2), interleukin-1 beta(IL-1b) and IL-6 in RAW264.7 cells.(3) The up-regulation of three mi RNA(mi R-155, mi R-125 a and mi R-146a) and the down-regulation of mi R-150 were significantly suppressed by MB-DCM in LPS-stimulated RAW264.7 cells.(4) MB-DCM blocked the nuclear translocation of p65 and decreased the phosphorylation of IkBa and p65.(5) In a mouse colitis model, DSS-induced weight loss and histological damage were significantly ameliorated by mulberry powder input or MB-DCM treatment.(6) The anti-inflammatory monomer compounds were identified as linoleic acid and ethyl g-linolenate.Taken together, our results indicate that mulberry and its DCM extracts, which possess anti-inflammatory properties both in vitro and in vivo, could be widely applied in animal agriculture, drug and food industries.