RESUMO
Neurodegenerative disease such as Alzheimer's disease, are progressive disorders which has been linked to oxidative imbalance and associated perturbations characterised by loss of memory, cognition and cholinergic deficit. To date, cholinesterase inhibition and neuroprotection are the two major strategies in drug development. Xylopia parviflora (Annonacea family) is a spice consumed in Cameroon and has been used in traditional medicine to treat various pains. In this study, X. parviflora was evaluated on behavioural studies, ion homeostasis, cholinesterase inhibitory and antioxidant activities. Rats were exposed to aluminium chloride (75 mg/kg) during 60 days, and were treated with the extract of X. parviflora (150 and 300 mg/kg BW) and two drugs references (Donepezil and Curcumin). Behavioural parameters were assessed using the Morris-Maze test and the Open Field, followed by biochemical investigations, namely, cholinesterase enzyme activity (AChE and BChE), oxidative stress (NO, MDA, GSH level, SOD and Catalase activities) and ion homeostasis (Mg2+ and Ca2+ levels). AlCl3 administration shows a decrease in learning and memory improvement during behavioural studies, significant alteration of the central cholinergic system characterised by an increase in AChE and BChE activities to 2.72 ± 0.002 mol/min/g and 5.74 ± 0.12 mol/min/g respectively, disturbance of ion homeostasis with an increase in Ca2+ level (25.68 ± 3.78 µmol/mg protein) and a decrease in Mg2+ level (15.97 ± 2.05 µmol/mg protein) and an increase in oxidative stress compared to the positive control group. Treatment with the different doses of X. parviflora increased memory and improved locomotion, improved cholinesterase activities, ion homeostasis and stabilized brain oxidative stress levels. The study suggests that X. parviflora could potentially be used for the management of some biochemical alterations associated with Alzheimer's disease. It could even be a good alternative to chemical drugs for neurotoxicity and memory enhancement.
RESUMO
Background: Many neurodegenerative such as Alzheimer's disease (AD) are characterized by cholinergic dysfunction and oxidative stress which is a key event in neuronal death process. Thus, anticholinesterase and anti-oxidation compounds are two promising strategies in the development of AD drugs. Beyond their culinary use, spices are today studies for health purpose. In this study, some spices consumed in Cameroon were evaluated for their anticholinesterase and neuroprotective effects. Methods: Colorimetric methods were used to determine total flavonoid and alkaloid content of a combinated extract (hydroethanolic + ethanolic extracts) of different selected spices. Aftermaths, anti-cholinesterase activity of spice extract was carried out using Ellman's method. Finally, neuroprotective effects performed on human SK-N-SH cells stressed with H2O2 by assessing neuronal survival ( resazurin assay) and neuronal death (LDH assay). Results: Flavonoid content of spices extract were ranged from 22.94 to 32.01 mg EQ/g DM and alkaloid content were ranged from 320 to 896 mg EQu/g DM. Among the spices studied, Xylopia parviflora presented the greatest acetylcholinesterase inhibition with an IC50 = 14 µg/mL. In Cell culture experiments, pre-incubation of SK-N-SH cell with the selected spices at different concentrations were improved neuronal survival and reduced the percentage of neuronal cells dead. Conclusion: The present results reveal that selected spices consumed in Cameroon have good anticholinesterase activity as well as neuroprotective effect on SK-N-SH which may provide new natural compounds that could help in the management of Alzheimer's disease.
