The anti-inflamm-aging and hepatoprotective effects of huperzine A in d-galactose-treated rats

Oxidative stress contributes to a chronic inflammatory process referred to as "inflamm-aging". Acetylcholinesterase inhibitors (AChEI) can enhance cholinergic transmission and act as anti-inflammatory agents via immunocompetent cells expressing α-7 acetylcholine receptors (AChR). The present study explores the possible role of huperzine A, a reversible and selective AChEI, against d-gal-induced oxidative damage, cell toxicity and inflamm-aging in rat livers. In two-month-old rats with normal liver function, an 8-week administration of d-gal (300 mg/kg subcutaneously (s.c.) injected), significantly increased hepatic impairment, ROS generation and oxidative damage, hepatic senescence, nuclear factor-kappa B (NF-κB) activation and inflammatory responses. An 8-week co-administration of both d-gal (300 mg/kg s.c.) and huperzine A (0.1 mg/kg s.c.) not only significantly decreased hepatic function impairment, ROS generation, oxidative damage, but also suppressed inflamm-aging by inhibiting hepatic replicative senescence, AChE activity, IκBα degradation, NF-κB p65 nuclear translocation and inflammatory responses. The expression levels of pro-inflammatory cytokine mRNA and proteins, such as TNFα, IL-1β and IL-6 decrease significantly, and the protein levels of the anti-inflammatory cytokine IL-10 display an obvious increase. These findings indicated that d-gal-induced hepatic injury and inflamm-aging in the rat liver was associated with the development of a pro-inflammatory phenotype in this organ. d-gal induced damage-associated molecular patterns (DAMPs) because oxidative damages might play an important role in d-gal-induced hepatic sterile inflammation. Huperzine A exhibited protective effects against d-gal-induced hepatotoxicity and inflamm-aging by inhibiting AChE activity and via the activation of the cholinergic anti-inflammatory pathway. The huperzine A mechanism might be involved in the inhibition of DAMPs-mediated NF-κB nuclear localization and activation.