Effects of hyperbaric oxygen combined with moxibustion on learning and memory functions and the expression of hippocampal neurotrophic factor in AD model rats

Objective To investigate the effects of hyperbaric oxygen (HBO) combined with moxibustion on learning and memory functions and the expression of hippocampal neurotrophic factor in rats with Alzheimer′s disease (AD). Methods The AD rat model was established by a single injection of aggregated Aβ25-35 into the hippocampus, and the rats were divided into the model group, the moxibustion group and the HBO combined with moxibustion group. The sham surgical group was injected with the same volume of normal saline at the same site. The learning and memory capacity of the rats was detected by Morris water maze. The positive expression of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in hippocampus was detected by immunohistochemistry, and the expression of BDNF and NGF proteins in hippocampus was detected by Western blotting. Results Compared with those of the sham surgical group, the escape latency and spatial exploration time of the model group significantly lowered (P<0.01), learning and memory capacity was severely impaired, the expression of BDNF and NGF in the hippocampus significantly decreased (P<0.01), with a neurotrophic deficiency. Following treatment with moxibustion or HBO combined with moxibustion, the learning and memory capacity of the model rats recovered to a certain extent (P<0.05 or P<0.01). The expression of BDNF and NGF in hippocampus was significantly up-regulated (P<0.01), with the therapeutic effects of the HBO combined with moxibustion group being obviously better than those of the moxibustion group (P<0.05). Conclusion HBO combined with moxibustion could significantly improve the learning and memory function of the AD model rats, up-regulate the expression of neurotrophic factor in hippocampus, and the effects were significantly superior to simple moxibustion treatment. Key words: Alzheimer′s disease; Hyperbaric oxygen; Moxibustion; Neurotrophic factor