Protective effects of compound Gastrodia elata formula on the cognitive impairment induced by simulated weightlessness in mice.

Abstract

Growing evidence highlights that long-term orbital flight may lead to structural changes in brains and cognitive impairments in astronauts. However, effective strategies to counteract these effects remain limited. Compound Gastrodia elata Formula (CGEF), composed of Gastrodia elata Bl., Polygonatum sibirium Red., and Poria cocos (Schw.) Wolf has been shown to improve learning and memory. The present study aimed to evaluate the effects and underlying mechanisms of CGEF in attenuating cognitive deficiency induced by simulated weightlessness in mice. A cognitive impairment model was induced in mice using Hindlimb unloading (HU) method. Cognitive function was assessed through Object recognition test (ORT), the Morris water maze (MWM), and the Step-down Test (SDT). Serum and hippocampus levels of inflammatory markers, including Interleukin-1 beta (IL-1β), Tumor Necrosis Factor alpha (TNF-α), and Interleukin-6 (IL-6) were evaluated using ELISA. Neurotransmitter concentrations in the hippocampus and cortex were measured using LC-MS/MS. While Brain-derived neurotrophic factor (BDNF) / Tropomyosin receptor kinase B (TrkB) protein expression signaling pathway in hippocampus was evaluated by western blot. Results showed that CGEF treatment significantly reversed the memory deficits induced by four weeks of HU exposure. Furthermore, CGEF treatment markedly suppressed the production of inflammatory factors. It also assisted in the recovery of neurotransmitter balance and regulated tryptophan metabolism to improve cognitive disorder. Western blotting analysis revealed that CGEF treatment upregulated the expression of Synaptophysin, Postsynaptic density 95 proteins, while also activating the brain-derived neurotrophic factor-Tropomyosin receptor kinase B pathway. These findings suggest that CGEF has substantial potential for development as an aerospace health product to improve memory decline associated with spaceflight.