Preclinical Evidence

Curcuminoids rescue long-term potentiation impaired by amyloid peptide in rat hippocampal slices
Synapse. 2011;65(7):572-82
Amyloid plaques, a neurotoxic agent, is a long peptide (Aβ peptide) consisting of 40–42 residues, which is known to cause substantial synaptic loss and neuronal cell degeneration in conditions like Alzheimer’s disease (AD). Although large amount of research has happened to understand the processing and clearance of Aβ peptides, limited success has been achieved in terms of availability of therapeutic options. Hence, newer options are being widely explored in this context.

Recently, medicinal plant-derived compounds, including turmeric have been explored for their potential advantages in treating AD. It has now been understood that Curcuminoids may interfere with the formation of amyloid plaques and reduce the toxicity of Aβ, because of their multitude activities.

To study the effect of Curcuminoids on Aβ-peptide-induced long-term potentiation (LTP) impairment, in an attempt to provide cellular basis of memory enhancement in AD.

Study Design:
  • Male Sprague–Dawley rats (4–6 weeks of age and 120–150 g of body weight) were used for slice electrophysiology experiments
  • Slice electrophysiology experiments were performed on transverse slices of hippocampi isolated from rat brain after the sacrifice
Results and Discussion:
  • Once the baseline responses were stabilized, brain slices were treated with Curcuminoids, as a result, baseline amplitude was significantly increased (p<0.05) 80 min. after the treatment compared to the vehicle-treated slices
  • Similarly, Curcumin also showed significant increase (p<0.05) in the baseline amplitude compared to vehicle
  • Application of Aβ peptide (500 nM) impaired both induction and maintenance/expression of LTP
  • Whereas, Curcuminoids (30 µM) blocked the Aβ peptide-induced LTP impairment, and further it resulted in suppression of the response that shifted amplitude even below baseline
  • Effect of individual components of Curcuminoids on Aβ peptide-induced LTP impairment showed that each component was effective at varying concentration and time; however, Curcumin was the most effective compound

Overall, curcuminoid mixture successfully restored the susceptibility for plastic changes in hippocampal region, which was impaired by Aβ peptide, thus restoring the LTP. Hence, it can be useful in providing pharmacological basis for the medicinal use of Curcuminoids in AD.