Abstract: Objective To investigate the effect of Rhizoma Atractylodis extract (ERA) in protecting gastric mucosa and
modulating gastrointestinal immune function of a rat model of spleen deficiency syndrome and elucidate the mechanism by
which ERA improves spleen deficiency syndrome. Methods Male rats fed with Xiaochengqi decoction and subjected to
irregular feeding to induce spleen deficiency syndrome. The established models were randomized into model group, high-,
moderate- and low-dose ERA groups, and domperidone group. After corresponding treatment for 30 days, the content of IgA
in the intestinal lavage fluid, serum IgG, and the indices of the spleen and thymus were determined. The pathological changes
in the gastric mucosa was observed with HE staining, gastric mucosal blood flow was evaluated with laser Doppler rheometry,
and the expression of TFF1 in the gastric mucosa and TLR4 expression in the colon tissue were detected with
immunohistochemistry. Results The rat models of spleen deficiency syndrome showed obvious abnormalities in gastric
mucosal morphology, blood flow and immunological indexes. Compared with the model rats, the rats receiving ERA
treatment as different doses all showed significant improvements in gastric mucosal morphology, blood flow volume, gastric
mucosa trefoil factor 1 (TFF1) expression, intestinal lavage fluid IgA content, serum IgG content, indices of the spleen and
thymus, and TLR4 expression in the colon TLR4 (P<0.05 or P<0.01). Conclusion ERA can inhibit gastric mucosal damage,
protect and repair the damaged mucosal tissues, and improve the immune function of in rats with spleen deficiency.