Figure 1.

Oral administration of procyanidins slowed destabilization of the medial meniscus (DMM)-induced OA disease progression in mice. Mice subjected to DMM were treated daily with procyanidins (PC) or vehicle (Veh) by oral gavage. The articular cartilage of the DMM-wounded knee in mice treated with procyanidins exhibited a reduced loss of cartilage as visualized by Safranin-O staining (A) and lower Osteoarthritis Research Society International (OARSI) scores (B) at 8 weeks following surgery compared to the articular cartilage of the DMM-wounded knee in mice treated with vehicle. Black arrows denote representative areas of cartilage degradation, such as proteoglycan loss, cartilage fibrillation and/or erosion. Regions of red indicate staining of proteoglycans in the articular cartilage, meniscus, or growth plate, by Safranin-O. The regions of light blue-green indicate subchondral bone. Scale bar = 100 µm. * p < 0.05 by t-test; n = 4/group.