The Mechanisms of Bushen-Yizhi Formula as a Therapeutic Agent against Alzheimer's Disease

Abstract

Bushen-Yizhi prescription (BSYZ) has been an effective traditional Chinese medicine (TCM) prescription in treating Alzheimer's disease (AD) for hundreds of years. However, the underlying mechanisms have not been fully elucidated yet. In this work, a systems pharmacology approach was developed to reveal the underlying molecular mechanisms of BSYZ in treating AD. First, we obtained 329 candidate compounds of BSYZ by in silico ADME/T filter analysis and 138 AD-related targets were predicted by our in-house WEGA algorithm via mapping predicted targets into AD-related proteins. In addition, we elucidated the mechanisms of BSYZ action on AD through multiple network analysis, including compound-target network analysis and target-function network analysis. Furthermore, several modules regulated by BSYZ were incorporated into AD-related pathways to uncover the therapeutic mechanisms of this prescription in AD treatment. Finally, further verification experiments also demonstrated the therapeutic effects of BSYZ on cognitive dysfunction in APP/PS1 mice, which was possibly via regulating amyloid-β metabolism and suppressing neuronal apoptosis. In conclusion, we provide an integrative systems pharmacology approach to illustrate the underlying therapeutic mechanisms of BSYZ formula action on AD.

Figure 1

Flowchart of the systems pharmacology approach for uncovering the pharmacological mechanisms of Bushen-Yizhi Formula (BSYZ) actions on AD by integrating target identification, network analysis and experimental validation. (A) Target prediction for candidate compounds in BSYZ, (B) Network analysis to explore the therapeutic mechanisms of BSYZ on AD. (C) Experimental validation in vivo to decipher the pharmacological mechanisms of BSYZ on AD.

Figure 2

Overlapping candidate targets among five herbs in the Bushen-Yizhi Formula. The corresponding number of targets for each herb is 149 (Shechuangzi, SC), 146 (Nvzhenzi, NZ), 142 (Gouqi, GQ), 146 (Renshen, RS) and 120 (Shouwu, SW).

Figure 3

Global drug-target network of candidate compounds in the Bushen-Yizhi Formula. SC, Shechuangzi; NZ, Nvzhenzi; GQ, Gouqi; RS, Renshen; SW, Shouwu. MD, Mudanpi.

Figure 4

Specific drug-target network of key herb ingredients in the Bushen-Yizhi Formula. SC, Shechuangzi; NZ, Nvzhenzi; GQ, Gouqi; RS, Renshen; SW, Shouwu.

Figure 5

Target-function network. A functional module is linked to a target if the target is involved in that biological process.

Figure 6

Integrated AD-pathway and therapeutic modules. The orange nodes are potential protein targets for candidate compounds in the BSYZ Formula.

Figure 7

Bushen-Yizhi Formula improved learning and memory abilities in APP/PS1 mice. (A) Escape latencies in water maze during the positioning navigation test. (B) Representative tracings of animal paths during the positioning navigation test on the 5^th day. (C) Number of times crossing the platform location during the probe trial. (D) Time spent in the target quadrant and in the opposite quadrant during the probe trial. (E) The partial index on the second day during the novel-object recognition test. (F) The partial index on the third day during the novel-object recognition test. Groups included a low-dose of BSYZ (1.46 g/kg/d), a medium-dose of BSYZ (2.92 g/kg/d) and a high-dose of BSYZ (5.84 g/kg/d). Data are shown as the mean ± SD (n = 11 in each group). ^#P < 0.05 and ^##P < 0.01 versus the wild-type group. ^*P < 0.05 and ^**P < 0.01 versus the model group.

Figure 8

Bushen-Yizhi Formula decreased amyloid-β levels and ameliorated the senile plaques in APP/PS1 mice. (A) The level of Aβ_1–42 in the hippocampus. (B,C) Quantitative graph (B) and representative images (C) of Thioflavine-S staining in the brains of APP/PS1 mice (magnification: 20x). Groups included a low-dose of BSYZ (1.46 g/kg/d), a medium-dose of BSYZ (2.92 g/kg/d) and a high-dose of BSYZ (5.84 g/kg/d). Data are shown as the mean ± SD (n = 11 in each group). ^#P < 0.05 and ^##P < 0.01 versus the wild-type group. *P < 0.05 and **P < 0.01 versus the model group.

Figure 9

Bushen-Yizhi Formula regulated amyloid-β metabolism and inhibited neuronal apoptosis in APP/PS1 mice. (A,B) The levels of proteins associated with amyloid-β metabolism in the hippocampus. (C,D) The levels of proteins associated with neuronal cell apoptosis in the hippocampus. Groups included a low-dose of BSYZ (1.46 g/kg/d), a medium-dose of BSYZ (2.92 g/kg/d) and a high-dose of BSYZ (5.84 g/kg/d). Data are shown as the mean ± SD (n = 11 in each group). ^#P < 0.05 and ^##P < 0.01 versus the wild-type group. *P < 0.05 and **P < 0.01 versus the model group.