Baoyuan jieyu formula ameliorates depression-like behaviour in rats induced by simulated long-term spaceflight composite stress through regulating MAPK and BDNF pathways

During space flight, astronauts are exposed to various influences of extreme environments and susceptible to develop depression-like behavior. Thus, this study aims to explore the molecular biological mechanism of the cause of depression-like behavior and reveal the effect of Baoyuan Jieyu Formula (BYJYF) on ameliorating depression-like behavior. Here, rats exposed to simulated long-term spaceflight composite stress (LSCS) reduced the sucrose preference rate (P <0.01), and the time of forced swimming immobility and the number of climbing times were also reduced (P < 0.01, P < 0.001). Moreover, the number of neurons in the CA3 region of the hippocampus decreased ( P< 0.01, P < 0.05, P < 0.001), the staining became weak, and the Nissl body decreased. Antibody chip detected a total of 854 protein molecules in the hippocampus, of which 51 and 37 proteins were significantly different in the LSCS group and LSCS+BYJYF group, respectively, focusing on signaling pathways such as MAPK and neurotrophin. Western blot was used to verify the related proteins of these two pathways. Conclusively, simulated LSCS can induce depression-like behavior and neuronal damage. BYJYF can reduce neuronal apoptosis, and promote neuron survival by regulating the MAPK and the neurotrophin signaling pathway to protect neurons and combat LSCS.