OBJECTIVE  To explore the effect of different processed products of Atractylodis Macrocephalae Rhizoma on intestinal mucosal barrier and intestinal flora in mice with ulcerative colitis.

METHODS  The Balb/c mice were randomly divided into blank group, model group, positive drug group, raw Atractylodis Macrocephalae Rhizoma group, wheat bran group, fried Atractylodis Macrocephalae Rhizoma group and bran-fried Atractylodis Macrocephalae Rhizoma group, with 8 mice in each group. Except for the blank group, the mice in the other groups were used to replicate the mouse model of ulcerative colitis by free drinking of 2.5% dextran sulfate sodium(DSS) aqueous solution. After successful preparation of the model, the therapeutic drugs were given to each group of mice by gavage. The blank group and the model group were given the same amount of normal saline by gavage. During the replication and treatment of the model, the pathological activity indexes of mice in each group were recorded and the disease activity index(DAI) of mice was evaluated. HE staining was used to observe the morphology of colon tissue and score. The levels of SIgA, Thl and Th2 cytokines IL-4, IL-18, TNF-α, IFN-γ and Th17/Treg cytokines IL-10, IL-17, TGF-β in serum tissue were measured by ELISA. The mRNA expression levels of tight junction proteins ZO-1, Occludin , Claudin-1, FFAR3 and mucin MUC2 in the colon tissue of each group were detected by PCR. Western blotting was used to detect the protein expression of tight junction proteins ZO-1, Occludin, Claudin-1, FFAR3 and mucin MUC2 in the colon tissue of each group. The diversity of intestinal flora in feces of mice was detected by 16S rRNA sequencing technology. The content of short-chain fatty acids in feces of mice was determined by GC-MS.

RESULTS  The each administration group could alleviate the symptoms of DSS-induced ulcerative colitis mice such as increased DAI and shortened colon length(P<0.05 or P<0.01), reduce the levels of pro-inflammatory factors such as IFN-γ, IL-17, IL-18 and TNF-α in model animals(P<0.05 or P<0.01), and increase the levels of anti-inflammatory factors such as SIgA, IL-10, IL-4 and TNF-β(P<0.05 or P<0.01). It could also affect the expression levels of key genes and proteins of intestinal mucosal barrier that ZO-1, Occludin 1, Claudin-1 and MUC2 in colonic mucosa(P<0.05 or P<0.01). It could also remodel the diversity of intestinal flora in model animals(P<0.05 or P<0.01) that increase the abundance of beneficial flora and reduce the abundance of harmful flora(P<0.05 or P<0.01). It could also adjust the level of intestinal short chain fatty acids(P<0.05 or P<0.01). Furthermore, the above effects of Atractylodis Macrocephalae Rhizoma were enhanced after bran-fried.

CONCLUSION The processing of Atractylodis Macrocephalae Rhizoma can enhance the effect of improvement of intestinal mucosal barrier and intestinal flora diversity in mice with ulcerative colitis which can improve the therapeutic effect of ulcerative colitis. In addition, the effect of bran stir-frying method is better than that of stir-frying.