Neuroprotective effects of the Chrysophyllum perpulchrum extract against an Alzheimer-like rat model of β amyloid1-40 intrahippocampal injection

Pacôme Kouadio N'Go; Omar Touhami Ahmed Ahami; Aboubaker El Hessni; Fatima-Zahra Azzaoui; Youssef Aboussaleh; Antoine Némé Tako

doi:10.1515/tnsci-2020-0183

Neuroprotective effects of the Chrysophyllum perpulchrum extract against an Alzheimer-like rat model of β amyloid_1-40 intrahippocampal injection

Transl Neurosci. 2021 Dec 16;12(1):545-560. doi: 10.1515/tnsci-2020-0183. eCollection 2021 Jan 1.

Authors

Pacôme Kouadio N'Go^{1

2}, Omar Touhami Ahmed Ahami², Aboubaker El Hessni³, Fatima-Zahra Azzaoui², Youssef Aboussaleh², Antoine Némé Tako⁴

Affiliations

¹ Peleforo GON COULIBALY University, Training and Research Unit of Biological Sciences, Department of Animal Biology, PO Box 1328, Korhogo, Ivory Coast.
² Clinical and Cognitive Neurosciences Group, Biology and Health Lab, Ibn Tofail University, PO Box 133, Kenitra, Morocco.
³ Genetic, Neuroendocrinology and Biotechnology Team, Biology and Health Lab, Department of Biology, Ibn Tofail University, PO Box 133, Kenitra, Morocco.
⁴ Neurosciences Team, Biology and Health Lab, Department of Biosciences, Felix Houphouet Boigny University, 01 BPV 34 Abidjan 01, Abidjan, Ivory Coast.

Abstract

Objective: Alzheimer's disease (AD) is a threatening disease for African populations in the upcoming years because of the increase in their expectancy of life. Here, we investigated whether natural products from Chrysophyllum perpulchrum as catechin and two dimeric procyanidins (catechin + hexose) could prevent progression of oxidative stress and cognitive changes using an AD-like rat model induced by Aβ_1-40 injection into the hippocampal CA1 subfield.

Methodology: Adult male Wistar rats were either microinjected with 1% ammonia as a vehicle (10 µL) or aggregated Aβ_1-40 at 10 µg bilateral hippocampus. On the 14th day of post-surgery, some Aβ rats were treated with melatonin (10 mg/kg i.p.) or with the Chrysophyllum perpulchrum extract (300 mg/kg p.o.), and some sham-operated rats received the extract alone. Cognitive abilities were tested with Y-maze, object recognition test and Morris Water Maze. Oxidative stress markers as well as the level of activated microglial cells were assayed in the brain.

Results: Aβ rats exhibited significant deficits of recognition memory and spatial learning. This was associated with an increase of microglia Iba 1 immunoreactivity as well as nitric oxide (NO), malondialdehyde and superoxide dismutase levels but not to the thiol content in the hippocampus, prefrontal cortex and septum of AD-like rats. The Chrysophyllum perpulchrum extract treatment mitigated Aβ-induced cognitive impairments and reversed microglia overactivation and subsequent generation of oxidative stress markers. Interestingly, the neuroprotective actions of the Chrysophyllum perpulchrum extract seem to be comparable to the control drug melatonin used albeit with some more beneficial effects.

Conclusion: These findings are preliminary and should be strengthened by more pharmacological studies of bioactive compounds of Chrysophyllum perpulchrum before being proposed as a promising drug against AD.

Keywords: Alzheimer’s disease; Chrysophyllum perpulchrum; microglia; oxidative stress markers; recognition memory; spatial learning.