Neuroprotective Effect of Spice Oleoresins on Memory and Cognitive Impairment Associated with Scopolamine-Induced Alzheimer’s Disease in Rats.

Oleoresins are a mixture of volatile and nonvolatile
components of concentrated forms of wholesome products. Even
though there are several reports on the effect of spice or spice
components on Alzheimer’s disease, there are no studies on the
effect of spice oleoresins. Hence, this study investigates the effect of
pepper, chili, and turmeric oleoresins in Alzheimer’s type of
cognitive impairment in the rat model. The animals were grouped
into six groups with six animals in each. They were (i) normal, (ii)
scopolamine, (iii) scopolamine + pepper oleoresin, (iv) scopolamine + turmeric oleoresin, (v) scopolamine + chili oleoresin and
(vi) scopolamine + donepezil for 13 days. Learning memory and acquisition memory were evaluated by a Morris water maze, and
the locomotor activity was assessed by an actophotometer. Biochemical parameters such as AChE, malondialdehyde, reduced
glutathione, glutathione peroxidase, superoxide dismutase, and catalase were studied. The brain histology was also studied. The
scopolamine treatment significantly (P < 0.05) elevated the locomotor activity and escape latency time and reduced the time spent in
the target quadrant, which was reversed in the case of the oleoresin treatment. Scopolamine-mediated changes in AChE,
malondialdehyde, reduced glutathione, glutathione peroxidase, superoxide dismutase, and catalase were improved after the treatment
with oleoresins. Among the three oleoresins, chili oleoresin were the most effective in behavioral activity, brain biomarkers, and
recovery of antioxidant capacities when compared to the drug treatment. Chili and pepper oleoresins improved the protection
against hippocampal damage. These oleoresins can be potent preventive/therapeutic agents against Alzheimer’s disease. This study
confirms the effect of spice oleoresins in Alzheimer’s disease condition