A persistent recruitment of neutrophils in the bronchi of
cystic fibrosis (CF) patients contributes to aggravate the airway tissue damage, suggesting the importance of modulating the expression of
chemokines, including
IL-8 during the management of the CF patients.
Polyphenols rich extracts derived from
waste water from olive mill, obtained by a molecular imprinting approach, have been investigated in order to discover compounds able to reduce
IL-8 expression in human bronchial epithelial cells (IB3-1 cells), derived from a CF patient with a ΔF508/W1282X mutant genotype and stimulated with
TNF-alpha. Initially, electrophoretic mobility shift assays (EMSAs) were performed to determine whether the different active principles were able to inhibit the binding between
transcription factor (TF)
NF-kappaB and
DNA consensus sequences. Among different representative active principles present in the extract, three compounds were selected,
apigenin,
oleuropein, and
cyanidin chloride, which displayed remarkable activity in inhibiting
NF-kappaB/
DNA complexes. Utilizing
TNF-alpha-treated IB3-1 cells as experimental model system, we demonstrated that
apigenin and
cyanidin chloride are able to modulate the expression of the
NF-kappaB-regulated
IL-8 gene, while
oleuropein showed no effect in regulating the expression of the gene
IL-8.