Trilobatin targets Nrf2 to ameliorate lipopolysaccharide-induced
depressive-like behavior: Involvment of microbiota-gut-brain axis
Abstract
Abstract Background and Purpose: Activation of Nrf2 holds great promise
for treating major depressive disorder (MDD). Trilobatin (TLB) is a
naturally occurring food additive conferring robust neuroprotection with
Nrf2 activation potency. This study was designed to explore whether TLB
is able to overcome MDD, and the role of Nrf2 in the antidepressant
effect of TLB. Experimental Approach: Mice and primary hippocampal
astrocytes challenged with lipopolysaccharide (LPS) were used to
decipher the effects of TLB on MDD. Nrf2-deficient mice were treated
with TLB and fecal microbiota transplantation (FMT) to validate the
potential targets of ICS Ⅱ on ALI. Key results: TLB ameliorated
depressive-like behavior in LPS-induced MDD mouse model. Single-cell RNA
sequencing analysis of the hippocampus revealed that astrocytes
exhibited distinct MDD-related clustering with increased Nrf2 in the
antidepressant effect of TLB. TLB directly bound to Nrf2 and increased
Nrf2-antioxidant response element (ARE) binding activity, which
ultimately restored mitochondrial function, reduced oxidative stress and
neuroinflammation. TLB improved intestinal microbiota dysbiosis and
attenuated intestinal barrier through increasing expressions of the
tight junction proteins. Fecal microbiota transplantation from
TLB-treated mice also ameliorated depression-like behavior after LPS
insult. Furthermore, by using genetically modified Nrf2-knockout mice,
we validated that the antidepressant effect of TLB were Nrf2/ARE
signaling dependent, suppressing astrocytes activation and gut
microbiota dysbiosis. These favorable effects of TLB were abrogated in
Nrf2 deficiency mice. Conclusions and implications: Our results reveal a
new-found pharmacological property of TLB: serves as a novel and
naturally-occurring Nrf2 activator to conquer MDD through modulating
microbiota-gut-brain axis.