Normal human fibroblasts undergo replicative senescence due to both genetic and environmental factors. The proteasome, a multicatalytic nonlysosomal protease, has impaired function during aging, while its increased expression delays senescence in human fibroblasts. Katsiki et al. [1] demonstrated that Oleuropein enhances proteasome activities in vitro more effectively than other known chemical activators, possibly through conformational changes of the proteasome. Moreover, continuous treatment of early passage human embryonic fibroblasts with Oleuropein decreases the intracellular levels of reactive oxygen species (ROS), reduces the amount of oxidized proteins through increased proteasome-mediated degradation rates and retains proteasome function during replicative senescence. Importantly, Oleuropein-treated cultures exhibit a delay in the appearance of senescence morphology, and their life span is extended by approximately 15% [1]

• [1] Katsiki M, Chondrogianni N, Chinou I, Rivett AJ, Gonos ES. The olive constituent Oleuropein exhibits proteasome stimulatory properties in vitro and confers life span extension of human embryonic fibroblasts. Rejuvenation Res. 2007; 10: 157–172. doi:10.1089/rej.2006.0513