A	Surface area of the Caco-2 cell monolayer
AB	Apical to basolateral side
AP	Apical side
BA	Basolateral to apical side
BL	Basolateral side
C	Polyphenol concentration at the acceptor side
C0	Polyphenol initial concentration at the donor side
CA	Caftaric acid
Caco-2	Caucasian colon adenocarcinoma cell line
D3G	Delphinidin-3-O-glucoside
DAD	Diode array detector
DMEM	Dulbecco’s modified eagle’s medium
DMSO	Dimethyl sulfoxide
dQ	Change of polyphenol concentration at the acceptor side
dt	Variation in time
ER	Efflux ratio
FBS	Fetal bovine serum
GA	Gallic acid
GSE	Grape skin polyphenolic extract
HBSS	Hank’s balanced salt solution
HEPES	4-(2-Hydroxyethyl)-1-piperazineethanesulfonic acid
HPLC	High performance liquid chromatography
K3G	Kaempferol-3-glucoside
K3Gal	Kaempferol-3-galactoside
LSD	Fisher‘s Least Significant Difference
M3G	Malvidin-3-O-glucoside
MIN	Minute
MTT	3-[4,5-Dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide
NEAA	Non-essential amino acid
Papp	Apparent permeability coefficient
PBS	Phosphate-buffered saline solution
Pet3G	Petunidin-3-O-glucoside
Q3G	Quercetin-3-glucoside
S1	Solution 1 (15 mg grape skin polyphenolic extract/mL)
S2	Solution 2 (22 mg grape skin polyphenolic extract/mL)
SA	Syringic acid
SD	Standard deviation
TE	Transport efficiency
TEER	Transepithelial electrical resistance
VR	Volume of the solution of the acceptor side