Abstract:

Objective: To investigate the protective effects of polysaccharides (LP) extracted from lotus bee pollen dried
by different drying methods on intestinal mucosal inflammation and intestinal barrier dysfunctions in mice induced by
5-fluorouracil (5-Fu). Methods: Mouse models of intestinal mucosal inflammation were established by induction with 5-Fu
and the model mice were grouped randomly and subjected to drug administration. The carbon-propelling rate was tested,
and colon length and Peyer’s patches (PPs) area were measured. The colon tissue was stained with hematoxylin-eosin (HE)
for histological section observation. Reactive oxygen species (ROS) and glutathione (GSH) contents, and catalase (CAT) and
GSH-Px activities in the supernatant of PPs homogenate were evaluated by biochemical assays. Tumor necrosis factor-α (TNF-α)
in the supernatant of colon tissue homogenate was determined through ELISA. Results: Compared with the normal group,
intraperitoneal injection of 5-Fu to mice significantly inhibited small intestinal transit (P < 0.05). LP extracted from lotus bee pollen
dried by hot air or vacuum pulsed drying improved colon shortening caused by 5-Fu (P < 0.05) and resulted in a significant or highly
significant increase of PPs area (P < 0.05 or P < 0.01). Moreover, compared with the 5-Fu-induced model group, LP combined with
5-Fu could significantly promote intestinal transit (P < 0.05), increase GSH content, and CAT and GSH-Px activities (P < 0.01 or
P < 0.05), and decrease obviously TNF-α contents (P < 0.05 or P < 0.01). HE staining results showed that LP could significantly
reduce the loss of colonic mucosa epithelium goblet cells, inflammatory cell infiltration and more shallow crypt depth induced
by 5-Fu. Conclusion: LP could relieve intestinal mucosal damage, improve intestinal transit dysfunction and protect against
intestinal oxidative damage in mice induced by 5-Fu. The polysaccharides extracted from lotus bee pollen subjected to vacuum
pulsed drying exhibited better activity than the polysaccharides extracted from hot air dried lotus bee pollen.

Key words: lotus bee pollen polysaccharide, 5-fluorouracil, intestinal mucosal barrier, oxidative damage, drying method