Effect of raw versus boiled garlic, onion and ginger extracts on platelet aggregation

The effects of aqueous extracts of raw and boiled garlic, onion and ginger were studied in vitro on the ADP-induced platelet aggregation using human platelet-rich plasma. Raw garlic extract completely inhibited ADP-induced platelet aggregation. Raw onion and ginger extracts also showed significantly inhibitory effects on the ADP-induced platelet aggregation, with 45.3% and 40.6% platelet aggregation of control, respectively. Boiled garlic, onion and ginger extracts revealed 56.4%, 64.0% and 83.4% platelet aggregation compared to 100% in the control, respectively. These results indicated that ADP-induced platelet aggregation was inhibited by garlic, onion and ginger extracts. The raw extract form demonstrated a stronger inhibitory effect than the boiled extract. The platelet aggregation inhibitory effects were the greatest for garlic, followed by ginger, and onion for both the raw and boiled forms.