Pomegranate polyphenol punicalagin improves learning memory deficits, redox homeostasis, and neuroinflammation in aging mice.

Alzheimer's disease (AD) is an irreversible, progressive brain disorder characterized by loss of memory and cognitive dysfunction in the aged. Despite remarkable advances in drug therapy, effective pharmacological interventions are rare. Punicalagin (PU) is an active antioxidant polyphenol found in pomegranates, raspberries, blueberries, and chestnuts that has attracted considerable attention owing to its strong antioxidant and anti-inflammatory properties. The current study focused on the neuroprotective effect of PU on aging mice and its potential mechanisms. In this study, we first evaluated the protective effect of PU on neuro-2a (N2a) cell damage mediated by BV2 microglia-induced neuroinflammation. The in vivo D-galactose (D-gal)-induced brain aging model demonstrated that PU ameliorated deficits in learning and memory and prevented neuroinflammation, which was evident from the decrease in microglial activation and astrocytosis. Furthermore, PU reduced the levels of malondialdehyde (MDA) and reactive oxygen species (ROS) and inhibited NLRP3 inflammasome activation, reducing the levels of inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-a (TNF-a), interleukin-18 (IL-18), and interleukin-1 beta (IL-1β) in both accelerated aging and naturally senescent mouse models. PU effectively improved neuroinflammation, learning and memory deficits, and redox homeostasis in aging mice, and it could be a potential therapeutic agent for AD.