Figure 5
Chrysin and its derivatives affect granule secretion in platelets. (A) human platelet-rich plasma was treated with vehicle [0.1% (v/v) DMSO] or diverse concentrations of chrysin, thio-chrysin, Ru-chrysin and Ru-thio-chrysin for 5 minutes prior to the addition of 0.5 μg/mL CRP-XL and incubation of 20 minutes at room temperature. The level of P-selectin (as a marker for α-granule secretion) was quantified using PECy5-labelled anti-human P-selectin antibodies by flow cytometry. The level of fluorescence obtained with vehicle control was taken as 100% to calculate the extent of inhibition in chrysin and its derivatives-treated samples. R represents ‘resting’ platelets. Cumulative data represent mean ± S.D. (n = 4). (B) human washed platelets were mixed with luciferin-luciferase reagent for two minutes followed by incubation with a vehicle control [0.1% (v/v) DMSO] or different concentrations of chrysin (i) or Ru-thio-chrysin (ii) for another 5 minutes. Platelets were then activated with 0.5 μg/mL CRP-XL and the ATP release was monitored for 5 minutes by lumi-aggregometry. The traces shown are representative of three separate experiments. The maximum ATP release obtained with vehicle control was taken as 100% to calculate the level of inhibition in chrysin and Ru-thio-chrysin treated samples (iii). Cumulative data represent mean ± S.D. (n = 3). *Indicates significance with respect to controls and #indicates significance with respect to the respective chrysin concentrations; p values shown (*p < 0.05, **p < 0.01 and ***,### p < 0.001) are as calculated by one-way ANOVA using Graphpad Prism.
