Oral ingestion of Ginkgo biloba extract reduces thiobarbituric acid reacting (TBAR) substances in washed platelets of healthy subjects

Thiobarbituric acid reacting (TBAR) substances were measured in washed platelets before and after ingesting 120 mg of standardized Ginkgo biloba extract daily for 3 months, in both normocholesterolemic (total cholesterol, 160 ± 27 mg/dl; age, 40 ± 13 years; n = 18) and hypercholesterolemic subjects (total cholesterol, 229 ± 35; age, 45 ± 8 years; n = 12). Ginkgo biloba extract significantly reduced cellular content of TBAR substances; 42 ± 21 vs. 28 ± 16 pmol/10⁷ platelets (p < 0.0025) and 50 ± 17 vs. 29 ± 13 pmol/10⁷ platelets (p < 0.004), for the normo- and hypercholemic subjects, respectively. In conclusion, Ginkgo biloba extract is a potent antioxidant in both groups, reducing TBAR substances possibly by inhibiting platelet COX-1 isoform activity.