Traditional Chinese Medicine Huannao Yicong Decoction Extract Decreases Tau Hyperphosphorylation in the Brain of Alzheimer’s Disease Model Rats Induced by Aβ_1–42

Abstract

Objective. Huannao Yicong Decoction (HYD, 还脑益聪方) has been shown to improve the learning and memory capabilities of Alzheimer's disease (AD) subjects. However, the underlying mechanism remains to be determined. Methods. Sixty Sprague-Dawley rats were divided equally and randomly into five different groups including control, positive control, and HYD granules of low dose, medium dose, and high dose by daily gavage. The sham-treated rats were also given the same volume of sterile water by gavage. Twelve SD rats were treated with the same amount of physiological saline. Twelve weeks later, learning and memory capabilities, Aβ content of the right brain and the expression of glycogen synthase kinase-3β (GSK-3β), total tau protein kinase (TTBK1), and cyclin-dependent kinase-5 (CDK-5) were tested. Results. Our results showed that high dose HYD treatment significantly improved the learning and memory capability of the AD rats and decreased the expression of TTBK1, GSK-3β, and CDK-5 in the hippocampal CA1 region. Conclusions. HYD treatment for 12 weeks significantly improved spatial learning and memory and effectively inhibited Aβ deposition, likely via reducing tau protein kinase expression and thus tau hyperphosphorylation and inflammatory injury. Taken together, these results suggest that HYD could be an effective treatment for AD.

Traditional Chinese Medicine Shenmayizhi Decoction Ameliorates Memory and Cognitive Impairment Induced by Multiple Cerebral Infarctions

“…After an entry point was chosen, the rats were released into the water facing the tank wall, and the number of times the rats crossed the platform site within 90 seconds was recorded. The MWM test protocol followed Cao's method [ 19 ]. After the MWM test, the rats were fasted for 12 hours, and serum and brain tissue samples were taken.…”

Tauopathy

“…However, since these strategies have yet to show significant benefit, new approaches are being probed, among which a scheme to enhancing protein homeostasis is an intriguing approach [147,149]. Other alternative approaches including using traditional Chinese medicine are also being pursued [150].…”

“…Several traditional Chinese medicines have been suggested that might be useful for treating tauopathies [150,165]. Huannao Yicong Decotion was shown to improve learning and memory in rat AD model.…”

“…Huannao Yicong Decotion was shown to improve learning and memory in rat AD model. Immunolabeling showed the expression levels of GSK3β, CDK5, and TTBK1 in CA1 region of the hippocampus are downregulated in the drug treatment groups [150]. Interestingly, it was also suggested that some traditional Chinese medicines, including Huperzine A and Tianma, could induce upregulation of ubiquitin ligases, indicating that they might facilitate protein degradation through ubiquitin-proteasome pathway [166].…”