Xanthohumol, a Prenylated Flavonoid from Hops (Humulus lupulus), Prevents Platelet Activation in Human Platelets
Figure 2
Effects of xanthohumol (XN) on FITC-triflavin binding to the α IIbβ 3 integrin, thromboxane B2 formation, and phospholipase Cγ2 (PLCγ2) phosphorylation in activated platelets. (a) The solid line represents the fluorescence profiles of (A) 2 μg/mL FITC-triflavin in the absence of XN as a positive control, (B) in the presence of 5 mM EDTA as a negative control, or in the presence of (C) 1.5 and (D) 3 μM XN, followed by the addition of 2 μg/mL FITC-triflavin. For other experiments, washed platelets were preincubated with 3 μM XN or 0.5% DMSO, followed by the addition of 1 μg/mL collagen, 60 μM arachidonic acid (AA), or 0.05 U/mL thrombin to trigger platelet activation. Cells were collected, and subcellular extracts were analyzed for (b) thromboxane B2 formation, and (c) PLCγ2 phosphorylation as described in Section 2. Profiles (a) are representative examples of five similar experiments. Data ((b) and (c)) are presented as the means ± S.E.M. ((b), ; (c), ). ** and ***, compared to the resting group; #, ## and ###, compared to the control (DMSO) group.
