Neurodegeneration, Neuroprotection, and Disease-Oriented NeuroscienceResearch PaperCurcuminoids enhance memory in an amyloid-infused rat model of Alzheimer's disease
Section snippets
Drugs and chemicals
Amyloid beta peptide (1–40) and ibotenic acids were purchased from the Sigma Chemical Company, St. Louis, MO, USA. Curcuminoids (greater than 95% purity; having bisdemethoxycurcumin 4.15%, demethoxycurcumin 16.53% and curcumin 79.52%) and its individual components, bisdemethoxycurcumin (78% purity), demethoxycurcumin (98% purity) and curcumin (98.35% purity) were generous gifts from the Sabinsa Group of Companies, 70 Ethel Road West, Unit 6, Piscataway, NJ 08854, USA. The purity of the
Ink injection into the hippocampus
In order to ensure that the injection procedure adopted in this study was accurate, blue ink was injected first. After completion of the injection procedure, the animal was sacrificed, the brain was isolated and sections were cut to locate blue ink, and presence of which in the hippocampal area (Fig. 3) confirmed that the injection procedure had been precise.
Effect of curcuminoids on memory in the Aβ-infused rat model of AD
To study the ameliorative effect of test compounds on spatial memory in the Aβ-infused rat model of AD, the vehicle was injected daily
Discussion
As memory loss is the main clinical symptom in AD, we studied the effect of curcuminoids using the Morris water maze test, which shows hippocampus-dependent learning and memory. Neurotoxin injection into the bilateral hippocampus resulted in memory loss in rats showing AD-like features. Treatment with curcuminoid mixture at low dose had no memory-enhancing effect evident at any time point, when compared to the neurotoxin group. However, the same dose (3 mg/kg) of the individual compounds showed
Conclusion
To summarize, in this study, individual compounds of the curcuminoids showed a better effect on memory compared to the parent curcuminoid mixture. Furthermore, we demonstrated that curcuminoid mixture, as well as individual components, showed a beneficial effect on the expression levels of genes involved in synaptic plasticity, although the effect varied with time and dose but beneficial effect was apparent even after short treatment of 5 days. Most importantly, we show here that, curcuminoids
Acknowledgments
This study was supported by the Aga Khan University Research Council (URC), Pakistan. Curcuminoid mixture and individual compounds (bisdemethoxycurcumin, demethoxycurcumin and curcumin) were generously provided by Dr. Muhammed Majeed, Founder and CEO of Sabinsa Corporation, New Jersey, U.S.A. We thank Dr. Graeme Cane, Head, Center of English Language, for language correction and Professor Arif Siddiqui for providing stereotaxic apparatus which was used for stereotaxic surgeries.
References (42)
- et al.
Pharmacological basis for the role of curcumin in chronic diseases: an age-old spice with modern targets
Trends Pharmacol Sci
(2009) - et al.
Inhibitory effect of curcuminoids on acetylcholinesterase activity and attenuation of scopolamine-induced amnesia may explain medicinal use of turmeric in Alzheimer's disease
Pharmacol Biochem Behav
(2009) - et al.
Curcumin enhances non-inflammatory phagocytic activity of RAW2647 cells
Biochem Biophys Res Commun
(2009) - et al.
Alzheimer's disease
Lancet
(2006) - et al.
Withanolides, a new class of natural cholinesterase inhibitors with calcium antagonistic properties
Biochem Biophys Res Commun
(2005) - et al.
Molecular understanding and modern application of traditional medicines: triumphs and trials
Cell
(2007) - et al.
Dose dependence and therapeutic window for the neuroprotective effects of curcumin in thromboembolic model of rat
Behav Brain Res
(2008) - et al.
Trends in ethnopharmocology
J Ethnopharmacol
(2005) - et al.
A new approach to the pharmacological regulation of memory: sarsasapogenin improves memory by elevating the low muscarinic acetylcholine receptor density in brains of memory-deficit rat models
Brain Res
(2005) - et al.
An important role of neural activity-dependent CaMKIV signaling in the consolidation of long-term memory
Cell
(2001)