Effect of Gecko Extract on Neuroinflammation in Rats with Reserpine-induced Depression via TLR4/NF-κB Pathway / 中国实验方剂学杂志

ABSTRACT

Objective:To investigate the effects and mechanism of Gecko extract for treatment of depression in rats. Method:The depression rats were induced by intraperitoneal injection of reserpine （0.5 mg·kg^-1）. The successfully modeled rats were randomly divided into model group， fluoxetine group （1.8 mg·kg^-1）， high dose and low dose groups of Gecko extract （12， 6 g·kg^-1）. The rats were given corresponding dose of drugs once a day for 10 days. After administration， the levels of neurotransmitters and inflammatory factors in serum and prefrontal cortex of rats were detected by enzyme-linked immunosorbent assay （ELISA）. The cell changes in hippocampal tissues were observed by hematoxylin-eosin （HE） staining. The mRNA levels of interleukin-6 （IL-6）， nuclear factor-<italic>κ</italic>B （NF-<italic>κ</italic>B）， and tumor necrosis factor （TNF-<italic>α</italic>） in the hippocampus of rats were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. The protein levels of Toll-like receptor 4 （TLR4） and NF-<italic>κ</italic>B in hippocampal tissues of rats were detected by Western blot. Result:Compared with the normal group， Gecko extract significantly shortened the immobility time of tail suspension and swimming in mice. Compared with model group， Gecko extract significantly reduced blepharoptosis and retention time in circles for the rats （<italic>P</italic><0.05）， increased the levels of 5-hydroxytryptamine （5-HT） and dopamine （DA） in serum （<italic>P</italic><0.05）， decreased the levels of Monoamine oxidase （MAO）， IL-6， and TNF-<italic>α</italic> in serum （<italic>P</italic><0.05） and prefrontal cortex （<italic>P</italic><0.05）， decreased the mRNA levels of inflammatory cytokines IL-6， NF-<italic>κ</italic>B and TNF-<italic>α</italic> and the protein expressions of TLR4 and NF-<italic>κ</italic>B in the hippocampus of rats （<italic>P</italic><0.05，<italic> P</italic><0.01）， and improved the pathological symptoms of the hippocampus. Conclusion:Gecko extract can significantly alleviate the pathological damage of depression and improve the symptoms of depression， and its mechanism may be due to inhibiting TLR4/NF-<italic>κ</italic>B signaling pathway and reducing the expression of NF-<italic>κ</italic>B， IL-6 and other inflammatory factors in the hippocampus of rats.