Effect of Antrodia camphorata on Inflammatory Arterial Thrombosis-Mediated Platelet Activation: The Pivotal Role of Protein Kinase C

Figure 4

Effects of Antrodia camphorata on Akt phosphorylation in collagen-activated platelets. Washed platelets (1.2 × 10⁹ cells/mL) were preincubated with 112 or 224 μg/mL of Antrodia camphorata and subsequently treated with 1 μg/mL of collagen to induce platelet activation. The platelets were collected, and the phosphorylation of (a) Akt in the subcellular extracts was analyzed. Data are presented as the mean ± SEM (; compared with solvent control platelets; compared with the collagen group). (b) Schematic illustration of Antrodia camphorata-mediated inhibition of platelet activation. Activated phospholipase Cγ2 (PLCγ2) catalyses the conversion of phosphatidylinositol 4,5-bisphosphate (PI4,5-P₂) into 1,2-diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP₃). DAG activates protein kinase C (PKC) and, subsequently, phosphorylation of a 47-kDa protein (p47). IP₃ induces the release of Ca²⁺ from the dense tubular system (DTS).

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