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 Gingko 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). Gingko biloba extract significantly reduced cellular content of TBAR substances; 42 +/- 21 vs. 28 +/- 16 pmol/10(7 platelets (p < 0.0025) and 50 +/- 17 vs. 29 +/- 13 pmol/10(7) platelets (P < 0.004), for the normo- and hypercholemic subjects, respectively. In conclusion, Gingko biloba extract is a potent antioxidant for both groups, reducing TBAR substances possibly by inhibiting platelet COX-1 isoform activity.