Biochemical and Histological Evaluations of Articular Cartilages Preserved in Cold Storage Solution Containing Green Tea Catechin, EGCG

Abstract

Although epigallocatechin-3-O-gallate(EGCG), a major poly phenolic constituent of green tea, has various pharmacological and biological activities including anti-carcinogenic, anti-thrombotic and anti-inflammatory effects, relatively a little is known about its beneficial effects on the non-frozen preservation of mammalian cells and tissues. In this study, articular cartilages from human knee joint were pretreated with 1 mM EGCG for 1 d and then preserved in serum-free RPMI 1640 media with 1% antibiotic-antimycotic solution at 4oC for 1, 2 and 4 wk. After cold preservation, chondrocyte viability(CCK-8 assay), biochemical and immunohistochemical composition[glycosaminoglycans and(type II)collagen], and biomechanical property(compressive elastic modulus) were assessed, respectively. Chondrocyte viability of cartilages pretreated with EGCG was significantly well-maintained for at least 2 wk with high contents of glycosaminoglycan and total collagen. These beneficial effects of EGCG pretreatment were more confirmed by histological and immunohistochemical observations showing well-preserved cartilaginous structures and delayed denaturation of the extracellular matrices in preserved specimens. The compressive elastic modulus(MPa) of cartilages pretreated with EGCG was well-maintained as much as that of fresh specimens without any increase as the progress in the preservation period. Here were also found that fluorescein isothiocyanate-conjugated EGCG were widely distributed through the matrix and clearly observed at the chondrocytes in the lacunas. Taking these results into consideration, it is suggested that EGCG may play an effective role in preserving articular cartilages, which be exploited to craft strategies for the long-term preservation of osteochondral allografts under cold storage conditions.