Cucumbers
have been anecdotally claimed to have anti-inflammatory
activity for a long time, but the active principle was not identified.
idoBR1, (2R,3R,4R,5S)-3,4,5-trihydroxypiperidine-2-carboxylic acid,
is an iminosugar amino acid isolated from fruits of certain cucumbers, Cucumis sativus (Cucurbitaceae). It has no chromophore
and analytically behaves like an amino acid making detection and identification
difficult. It has anti-inflammatory activity reducing lipopolysaccharide
(LPS)-induced tumor necrosis factor alpha (TNF-α) in THP-1 cells
and ex vivo human blood. It showed selective inhibition
of human α-l-iduronidase and sialidases from both bacteria
(Tannerella forsythia) and human THP-1
cells. idoBR1 and cucumber extract reduced the binding of hyaluronic
acid (HA) to CD44 in LPS-stimulated THP-1 cells and may function as
an anti-inflammatory agent by inhibiting induced sialidase involved
in the production of functionally active HA adhesive CD44. Similar
to the related iminosugars, idoBR1 is excreted unchanged in urine
following consumption. Its importance in the diet should be further
evaluated.