Bee pollen (BP) shows profound gut-protecting potentials.
BP lipids
(BPLs) mainly composed by phospholipids and polyunsaturated fatty
acids might be one of the important contributors, while how BPL exerts
gut-protecting effects and is transported through intestinal cell
monolayers need to be investigated. Here, we exploited a strategy
that combines an UPLC-Q-exactive orbitrap/MS-based lipidomics approach
with a human intestinal cell (Caco-2) monolayer transport model, to
determine the transepithelial transportation of BPL from Camellia sinensis L. (BPL-Cs), in pathological conditions.
The results showed that BPL-Cs protected Caco-2 cells against dextran
sulfate sodium (DSS)-induced intestinal barrier dysfunction by improving
cell viability, maintaining membrane integrity, increasing tight junctions
(ZO-1 and Claudin-1), and eliciting the expressions of antioxidative-related
genes (NQO1, Nrf2, Txnrd1, and GSTA1). Lipidomics analysis revealed that
DSS suppressed the transport and uptake of most of BPL-Cs including
glycerophospholipids, sphingomyelins, and glycosylsphingolipids.
Pretreatment with BPL-Cs significantly regulated glycerophospholipid
and sphingolipid metabolisms, potentially involved in building permeability
barriers and alleviating intestinal oxidative stress. Finally, eight
classes of lipids were identified as the potential biomarkers for
evaluating DSS-induced Caco-2 cell dysfunctions and BPL-intervened
modulation. These findings shed light on the development of BPL as
gastrointestinal protective food supplements in the future.