Acetylcholinesterase inhibitory, anti-inflammatory and antioxidant properties of some Cameroonian medicinal plants used to treat some neurological disorders

Abstract

Background: Besides the principal hallmark of Alzheimer’s disease (AD) and Parkinson’s disease (PD) which is accumulation of mis-folding protein in the brain; cholinergic deficit, neuro-inflammation and oxidative stress are also implicated in the pathogenesis of the above-mentioned diseases. In the present study, different plant parts were collected in an ethnopharmacological survey carried out in the Noun Division (West Region, Cameroon).

Methods: A total of 29 methylene chloride-methanol (1:1; v/v) extracts were prepared and screened for their acetylcholinesterase inhibitory activity, anti-inflammatory activity and antioxidant activity. Total phenolic and flavonoid contents were also quantified.

Results: The extract of Crinum purpurascens had strong activity against acetylcholinesterase with IC50 value of 99.40 µg/mL. Most of the extracts tested inhibited nitric oxide (NO) production in a dose dependent manner on LPS-stimulated RAW 264.7 macrophage cells. The extract from C. purpurascens had strong activity against NO production (IC50 of 12.8 µg/mL). The extract of Annona muricata seeds had the highest 15-lipoxygenase inhibitory activity with IC50 of 30.43 µg/mL. In addition, most of the extracts had good antioxidant potential, particularly the extracts of Annona senegalensis, Dacryodes edulis and Cola acuminata. High levels of total phenolic content were found in A. senegalensis and C. acuminata.

Conclusion: The traditional use of these medicinal plants for the treatment of neurological disorders was established through this result. Further experiments for the discovery of the components in the most active extract (C. purpurascens) are underway.