Abstract:
The cholinergic theory claims that the decline in cognitive functions in dementia is predominantly
related to a decrease in cholinergic neurotransmission. This hypothesis has led to great interest in
the putative involvement of the cholinergic neurotransmission in learning and memory processes.
Turmeric, a potent anti-inflammatory compound, like donepezil has shown to have sound effect on
cholinergic system improving memory and learning. BALB/c mice were administrated Scopolamine
(1mg/Kg/day) through subcutaneous injections for a period of 26 days. On 11 day, Donepezil (4mg/Kg/day)
and Turmeric (20mg/Kg/day) was given mixed in feed. Novel recognition test, fear contextual and fear
conditioning test a memory tests were performed to evaluate memory consolidation and acquisition. RT PCR was used to measure the mRNA expression of M1, M3, and M5 receptors in the cortex. Turmeric
treatment significantly improved the expression of cholinergic muscarinic receptors M1 and M5 in the
cortex as compared to Scopolamine-induced amnesia group. Moreover, turmeric significantly enhanced the
expression of α7 in control and treated groups, the expression of α4 is reduced in turmeric treated
and control group as compared to scopolamine-induced amnesia group and there is no-significant
change in expression in β2 gene in groups. There were four proteins differentially expressed in
turmeric treated group. The impairment in cortex dependent learning and memory was inverted in
Scopolamine-induced amnesia group as evident from improvement in fear conditioning (p<0.001),
contextual (p< 0.001), and fear extinction (p<0.001) in turmeric treated group as compared to Scopolamine induced amnesia group. Recognition memory was also improved (p<0.001) following turmeric
administration as compared to scopolamine-induced amnesia, suggesting the positive effect of turmeric.
Furthermore, turmeric show significant improvement in low scoring PAL and RT test in human aged
subject as compared to placebo group of human subject. Therefore in the light of these findings turmeric
Abstract
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may serve as a potential candidate in improving cognitive functions. It can also act as a therapeutic option
for neurodegenerative disorders.
