Retracted: Mechanisms and effects of curcumin on spatial learning and memory improvement in APPswe/PS1dE9 mice
Authors: Ying Ren
Hong Wang
Haiyun Sun
Caixin Su
Jinzhou Tian
Shucui Jiang
Ruisheng Li
Jing Shi
Jinduo Yang
Jianning Sun
Pengwen Wang
Journal: Journal of neuroscience research (2014)
Discipline: NEUROSCIENCE & BEHAVIOR
Keywords: APPswe/PS1dE9 double transgenic mice; Aβ40 and Aβ42; Morris water maze test; curcumin; insulin-degrading enzyme
Affiliations: Key Laboratory of Chinese Internal Medicine, Ministry of Education, Beijing University of Chinese Medicine (BUCM), China; Key Laboratory of Pharmacology of Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, China.

Abstract:  Evidence suggests that curcumin, the phytochemical agent in the spice turmeric, might be a potential therapy for Alzheimer's disease (AD). Its antioxidant, anti-inflammatory properties have been investigated extensively. Studies have also shown that curcumin can reduce amyloid pathology in AD. The underlying mechanism, however, is complex and is still being explored. In this study, we used the APPswe/PS1dE9 double transgenic mice, an AD model, to investigate the effects and mechanisms of curcumin in the prevention and treatment of AD. The water maze test indicated that curcumin can improve spatial learning and memory ability in mice. Immunohistochemical staining and Western blot analysis were used to test major proteins in β-amyloid aggregation, β-amyloid production, and β-amyloid clearance. Data showed that, 3 months after administration, curcumin treatment reduced Aβ40 , Aβ42 , and aggregation of Aβ-derived diffusible ligands in the mouse hippocampal CA1 area; reduced the expression of the γ-secretase component presenilin-2; and increased the expression of β-amyloid-degrading enzymes, including insulin-degrading enzymes and neprilysin. This evidence suggests that curcumin, as a potential AD therapeutic method, can reduce β-amyloid pathological aggregation, possibly through mechanisms that prevent its production by inhibiting presenilin-2 and/or by accelerating its clearance by increasing degrading enzymes such as insulin-degrading enzyme and neprilysin. 

Retracted: Yes

PubPeer comments:
 Figure 2, HDC panel: ![file] Fig 4, Wild panel: ![file] Fig 4, Control panel: ![file] Figure 4, RSG panel: ![file] If a single small motif repeated in just one panel, that could be dismissed as happenstance. But finding so many, naturally it causes concern. Here s the HDC panel of Figure 5: ![file] , 
 Figure 6 has six panels: ![file] How many conditions are there really? ![file] , 
 One more, because why not? Fig 7, LDC panel. ![file] , 
 Figure 7, findings of #3 with some additional ones. ![file] , 
 #1 One more for for Figure 4, Wild panel: ![file] , 
 #4 Fig 7, LDC panel revisited. ![] , 
 The paper is now marked as  Retracted on the JNR contents page, but as yet there is no retraction notice, or a date, or any indication in PubMed. Does anyone have further information? ![file] , 
 #7 2020 retraction notice. https: onlinelibrary.wiley.com doi abs 10.1002 jnr.24580?af=R The above article, published online on 23 November 2013 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal s Editoru2010inu2010Chief, Dr Eric M. Prager, and Wiley Periodicals, Inc. The retraction has been agreed due to the unreliable nature of the figures presented. Concerns were originally raised via PubPeer . After an investigation conducted by the journal s Editoru2010inu2010Chief, in accordance with the guidelines from the Committee on Publication Ethics (COPE), it was determined that the figures presented in the article could not be validated. Consequently, the main findings of the article, and the conclusions drawn, can no longer be relied upon. As recommended by COPE s guidelines, we have therefore decided to retract the article. We have attempted to contact the authors for comment but have been unsuccessful in our efforts. REFERENCE Wang, P., Su, C., Li, R., Wang, H., Ren, Y., Sun, H., u2026 Jiang, S. (2014). Mechanisms and effects of curcumin on spatial learning and memory improvement in APPswe PS1dE9 mice. Journal of Neuroscience Research, 92, 218u2013231. https: doi.org 10.1002 jnr.23322 ,