OBJECTIVE

2

To explore the ameliorative effect and potential mechanism of vitexin on inflammation in ulcerative colitis （UC） mice.

METHODS

2

The UC mice model was established by continuous administration of 3% dextran sulfate sodium solution for 5 days. Mice with successful modeling were randomly divided into UC group， vitexin low- and high-dose groups （vitexin-L and vitexin-H groups， 40， 80 mg/kg）， mesalazine group （400 mg/kg）， and vitexin-H+recombinant Jagged canonical Notch ligand 1 （rJagged-1） group （vitexin-H+rJagged-1 group， 80 mg/kg vitexin+1 mg/kg rJagged-1）， with 12 mice in each group. Another 12 normal mice were used as the control （CK） group. Mice in each group were administered the corresponding drugs or the corresponding drugs and normal saline by gavage and intraperitoneal injection once daily for 7 consecutive days. General conditions were observed during the experiment. At 24 h after the last administration， the disease activity index （DAI） score was evaluated. Colonic histopathological morphology was observed and scored. Macrophage polarization levels in the spleen and colon tissues were measured. The protein expressions of interleukin-6 （IL-6）， IL-10， tumor necrosis factor-α （TNF-α）， transforming growth factor-β

1

（TGF-β

1

）， Jagged-1， Notch1 and Notch intracellular domain （NICD） in colonic tissues were determined.

RESULTS

2

Compared with the UC group， the symptoms （reduced food and water intake， dull fur， etc.） and pathological changes （epithelial cell shedding， inflammatory cell infiltration， etc.） were significantly improved in the vitexin-L， vitexin-H and mesalazine groups. DAI scores， colonic histopathological scores， M1 macrophage contents in spleen tissue， M1/M2 macrophage ratios， M1 macrophage proportions in colon tissue， and protein expressions of IL-6， TNF-α， Jagged-1， Notch1 and NICD in colon tissue were significantly decreased （

P

＜0.05）. Meanwhile， the M2 macrophage contents in spleen tissue， M2 macrophage proportions in colon tissue， and protein expressions of IL-10 and TGF-β

1

in colon tissue were significantly increased （

P

＜0.05）. Moreover， the improvement effects in the vitexin-H and mesalazine groups were significantly superior to those in the vitexin-L group （

P

＜0.05）. Compared with the vitexin-H group， the above symptoms and pathological changes were aggravated， and all quantitative indicators were significantly reversed in the vitexin-H+rJagged-1 group （

P

＜0.05）.

CONCLUSIONS

2

Vitexin can ameliorate the inflammation of UC mice， which is associated with its inhibition of the Jagged-1/Notch1 pathway and regulation of macrophage polarization （inhibition of M1-type polarization and promotion of M2-type polarization）.