Effects of Hops Ethyl Acetate Extract on Lipopolysaccharide-induced
Depression-like Behavior and the Underlying Mechanism
Abstract
Background and Purpose There has been increasing interest in the causes
and pathogenesis of depression, which is a common psychiatric disorder.
We aimed to investigate the protective effect of hops ethyl acetate
extract (HEA) on neuroinflammation-mediated lipopolysaccharide
(LPS)-induced depression-like symptoms. Experimental Approach A battery
of behavior tests, including the open field test (OFT), elevated plus
maze (EPM), tail suspension test (TST), and forced swimming test (FST),
was used to evaluate the effects of HEA on LPS-induced depression.
Furthermore, the levels of inflammatory factors (tumor necrosis factor-α
[TNF-α], interleukin-1β) and norepinephrine were evaluated through
enzyme-linked immunosorbent assay. The density of hippocampal dendritic
spines was assessed through Golgi staining. Finally, the toxicological
effects of hops extract on depression in mice were further analyzed
through hematoxylin and eosin staining and blood biochemistry. Key
Results Based on the OFT, EPM, TST, and FST results, oral gavage HEA
prevented LPS-induced depression-like behaviors in the mice. Further,
HEA reduced neuroinflammation, increased norepinephrine levels, and
increased the density of hippocampal dendritic spines. Finally, blood
biochemistry and HE staining did not reveal any side effects or toxicity
of HEA. Conclusion and Implications Our findings indicated that HEA is a
potential compound for treating depression.