Fig. 3.

Effects of crude saponin fraction (CSF) on fibrinogen binding to integrin α_IIbβ₃ in collagen-activated platelets. (A) The inhibitory effects of CSF on fibrinogen binding to integrin α_IIbβ₃ in collagen-activated platelets were measured by flow cytometry. Washed platelets (3 × 10⁸/mL) were pretreated with vehicle (dimethyl sulfoxide) or CSF at concentrations ranging from 50 to 400 μg/mL. Collagen was then incubated with human fibrinogen labeled with Alexa Fluor 488 (20 μg/mL) for 5 minutes. The cells were subsequently fixed with 0.5% paraformaldehyde at 4°C for 30 min. (B) Graphs showing fluorescent intensity present the data from one experiment but are representative of four independent trials. Data are expressed as the mean fluorescence intensity of fibrinogen-positive platelets. Each graph presents the results expressed as percentage of gated cells. * p < 0.001 compared with the agonist control. Coll, collagen.