Procyanidin B3 is a polyphenol flavonoid dimer of (+)-catechin that has been found in G. biloba and has diverse biological activities.^1,2,3 It inhibits aggregation of amyloid-β (1-42) (Aβ42) with an IC50 value of 3.54 μM and destabilizes preformed Aβ42 fibrils (EC50 = 5.12 μM).¹ Procyanidin B3 (1 mM) reduces oxidation of linoleic acid and scavenges 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals in cell-free assays.² It inhibits hydrogen peroxide-induced production of inducible nitric oxide synthase (iNOS) and apoptosis in primary murine chondrocytes.³ Procyanidin B3 (0.01 mg/kg) reduces chondrocyte apoptosis, pseudocapsule thickness, and the frequency of ectopic cartilage formation in a mouse model of surgically induced osteoarthritis.