Experimental immunologyThe effects of EGb761 on lipopolysaccharide-induced depressive-like behaviour in C57BL/6J mice

There is an increasing body of evidence for the involvement of inflammation and brain-derived neurotrophic factor (BDNF) in depression. Ginkgo extract EGb761 possesses anti-inflammatory, anti-oxidative, anti-arteriosclerosis, and neuroprotective activities. But the effect of EGb761 on lipopolysaccharide (LPS)-induced depressive-like behaviours has not been investigated. The present study mainly aimed to examine the antidepressant-like activities of Ginkgo extract EGb761 in mice after lipopolysaccharide administration. C57BL/6J male mice were pretreated with EGb761 or vehicle for 10 days. Then, a single dose of lipopolysaccharide was intraperitoneally administrated to mice to induce depressive-like behaviour. Forced swim test (FST), tail suspension test (TST), and sucrose preference test were performed to evaluate the depressive-like behaviours of the mice. Locomotor activity was examined by open field test. Levels of brain-derived neurotrophic factor, TNF-α, IL-1β, IL-6, IL-17A, and IL-10 in hippocampus tissue homogenate were measured using ELISA kits. We found that LPS administration induced significant depressive-like behaviours, higher levels of tumour necrosis factor α (TNF-α), interleukin (IL) 1β, IL-6, and IL-17A, but lower levels of BDNF and IL-10 in hippocampus tissue homogenate of the mice from the vehicle group compared to the control mice. Pretreatment with middle dose (100 mg/kg/day) and high dose (150 mg/kg/day) of EGb761 significantly attenuated depressive-like behaviours without affecting spontaneous locomotor activity, and inhibited the changes of hippocampal cytokines and BDNF induced by LPS administration. We conclude that EGb761 has antidepressant-like activities in mice with LPS-induced depressive-like behaviours.