Antidepressant-like effects of Schisandrin on lipopolysaccharide-induced mice : Gut microbiota, short chain fatty acid and TLR4/NF-κB signaling pathway.

Growing evidence shows that gut microbiota and neuroinflammatory responses play a critical role in the pathogenesis of depression. Our previous study demonstrated that schisandrin (SCH) could reduce proinflammatory factors of depressive mice. Therefore, our present study is to research the potential connection between gut microbial and anti-inflammatory effects of SCH on a depressive mouse model induced by lipopolysaccharide (LPS). We found that SCH pre-treatment could decrease the immobility time of forced swimming test (FST) and tail suspension test (TST). And the results of 16S rRNA demonstrated that SCH pre-administration attenuated the dysbiosis of gut microbiota of depressive mice, along with altered fecal short-chain fatty acids (SCFAs). Furthermore, SCH reduced the levels of proinflammatory factors of depressive mice and the expression of TLR4/NF-κB signaling pathway in the hippocampus. Overall, our study indicated that SCH might recover the gut microbial disorder of depressive mice through suppressing the expression of TLR4/NF-κB signaling pathway.