Effects
of bioactive peptides and their derivatives on TNF-induced
VCAM-1 expression: (A) bioactive peptides (IRW and IQW); (B) respective
dipeptides of IRW (IR and RW); (C) respective dipeptides of IQW (IQ
and QW); (D) individual amino acids (I, R, Q, and W); peptide sequence
combination of respective amino acids (I+R+W and I+Q+W). Confluent
HUVEC monolayers were pretreated for 20 h with peptides and amino
acids prior to 4 h of incubation with 5 ng/mL TNF. VCAM-1 protein
levels are expressed as fold increase over the untreated control.
Bars represent mean values (mean ± SEM, n =
8 independent experiments). Representative Western blots are shown
below. (###) P < 0.001, (##) P < 0.01, and (#) P < 0.05, compared to untreated
control; (∗∗∗) P < 0.001,
(∗∗) P < 0.01, and (∗) P < 0.05, compared to TNF alone. Bar graph having lighter
color indicates that a particular treatment has a significant effect
compared with TNF alone.