Protective Effect of Flavonoids from Ziziphus jujuba cv. Jinsixiaozao against Acetaminophen-Induced Liver Injury by Inhibiting Oxidative Stress and Inflammation in Mice

(ZJF). The composition of ZJF was analyzed by high performance liquid chromatography (HPLC) and Liquid chromatography-mass spectrometry (LC-MS), and antioxidant properties were investigated by biological assays in vitro. The hepatoprotective activity of ZJF was evaluated in acetaminophen (APAP)-treated BALB/c mice. Results indicate that ZJF displayed significant antioxidant capacity. Pretreatment with ZJF significantly decreased APAP-elevated serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin (TB). Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were enhanced with ZJF administration, while malondialdehyde (MDA) level and glutathione (GSH) depletion were reduced. Meanwhile, ZJF reversed the suppression of nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, and up-regulated the protein expression of NAD(P)H: quinone oxidoreductase 1(NQO1) in liver damage mice. Furthermore, ZJF attenuated APAP-induced inflammatory mediator production, such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β). Expression of p65 showed that ZJF dampened nuclear factor-κB (NF-κB) activation. The results strongly indicate that the hepatoprotective role of ZJF in APAP-induced hepatotoxicity might result from its induction of antioxidant defense via activation of Nrf2 and reduction of inflammation via inhibition of NF-κB.