Kaempferol Protects Mice from D-GalN/LPS-induced Acute Liver Failure by
Regulating the Autophagy Pathway
Abstract
Kaempferol, a flavonoid compound, has various biological functions.
Acute liver failure (ALF) is a lethal clinical syndrome with severe
liver function damage. In this study, we explored the mechanisms
underlying the therapeutic effect of kaempferol in ALF. The ALF mouse
model was established using D-galactosamine (D-GalN, 700
mg/kg)/lipopolysaccharide (LPS, 10 μg/kg). Two hours before the
administration of D-GalN/LPS, different group of mice were pretreated
according different doses of kaempferol, 6 hours after injection of
D-GalN/LPS, and then killed. The survival rate, liver function and
inflammatory cytokine levels were assessed. It was determined whether
kaempferol pretreatment protected hepatocytes from ALF induced by
D-GalN/LPS via autophagy pathway in vivo and in vitro. Pretreatment with
a high dose of kaempferol significantly decreased the survival rate and
increased severe liver damage; however, pretreatment with a low dose of
kaempferol showed the opposite effect. Furthermore, pretreatment with a
high dose of kaempferol augment the levels of proinflammatory cytokines
and markers of the MAPK signaling pathway, while pretreatment with a low
dose of kaempferol showed the opposite effect. Additionally,
pretreatment with a high dose of kaempferol decreased autophagy, but
pretreatment with a low dose of kaempferol increased autophagy in vivo
and in vitro. It was also proved that pretreatment with 3-methyadenine
(3- MA) or Atg7 siRNA to inhibit autophagy partially negated the
hepatoprotective effect of kaempferol (5 mg/kg) pretreatment in ALF mice
induced by D-GalN/LPS. Our findings demonstrate that effects of
different doses of kaempferol on D-GalN/LPS-induced ALF is remarkably
different by regulating the autophagy pathway.