ALBERT

Description: Human mesenchymal stem cells (hMSCs) are considered a highly promising candidate cell type for cell-based tissue engineering and regeneration because of their self-renewal and multi-lineage differentiation characteristics. Increased levels of reactive oxygen /nitrogen species (ROS/ RNS) are associated with tissue injury and inflammation, impact a number of cellular processes, including cell adhesion, migration, and proliferation, and have been linked to cellular senescence in MSCs, potentially compromising their activities. Naturally occurring polyphenolic compounds (polyphenols), epigallocatechin-3-gallate (EGCG) and curcumin, block ROS/RNS and are potent inflammation-modulating agents. However, their potential protective effects against oxidative stress in hMSCs have not been examined. In this study, we carried out a systematic analysis of the effects of polyphenols on hMSCs in their response to oxidative stress in the form of treatment with H 2 O 2 and nitroso-N-acetylpenicillamine (SNAP), respectively. Parameters measured included colony forming activity, apoptosis, and the levels of antioxidant enzymes and free reactive species. We found that polyphenols reversed H 2 O 2- induced loss of colony forming activity in hMSCs. In a dose-dependent manner, polyphenols inhibited increased levels of ROS and NO, produced by H 2 O 2 or SNAP, respectively, in MSCs. Notably, polyphenols rapidly and almost completely blocked H 2 O 2 -induced ROS in the absence of significant direct effect on H 2 O 2 itself. Polyphenols also protected the antioxidant enzymes and reduced apoptotic cell death caused by H 2 O 2 exposure. Taken together, these findings demonstrate that EGCG and curcumin are capable of suppressing inducible oxidative stress in hMSCs, and suggest a possible new approach to maintain MSC viability and potency for clinical application. J. Cell. Biochem. © 2012 Wiley Periodicals, Inc.