Abstract
Replicative senescence (RS) of human diploid fibroblasts (HDFs) has become a classical model of aging and HDFs, such as WI-38 cells, display increased cellular oxidant production associated with RS. Several phenomena associated with RS are also observed in stress-induced replicative senescence (SIPS). In particular, SIPS of WI-38 cells caused by hydrogen peroxide (H2O2) is a useful and reasonable cellular aging model for evaluating the effects of potential anti-aging agents against oxidative stress. We used this well-established model to evaluate the anti-aging effect of Kangen-karyu, focusing on its antioxidant activity. Treatment of WI-38 cells undergoing SIPS caused by H2O2 with Kangen-karyu extract significantly reduced reactive oxygen species (ROS) generation and lipid peroxidation levels. In addition, the intracellular GSH levels, reflecting cellular ROS generation, were reduced by treatment with Kangen-karyu extract. These results suggest that Kangen-karyu attenuated the age-associated increase of cellular oxidative damage. Moreover, Kangen-karyu extract normalized the G0/G1 phase arrest and reversed the diminished cell viability resulting from exposure to H2O2. Furthermore, the extract prolonged the lifespan of WI-38 cells undergoing SIPS. This study suggests that Kangen-karyu may delay the aging process in cells undergoing SIPS by attenuating oxidative damage.
