Comparative assessment of antioxidant and cholinesterase inhibitory properties of the marigold extracts from Calendula arvensis L. and Calendula officinalis L.

Calendula sp. is an important medicinal and industrial plant with various bioactivities. In this study, we examined enzyme inhibitory effects of the n-hexane, dichloromethane, acetone, ethyl acetate, methanol, and water extracts of the leaf and flowers of Calendula arvensis L. and C. officinalis L. against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The extracts were screened for their antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion-chelating capacity and ferric-reducing antioxidant power (FRAP) assays at 250, 500, and 1000 μg mL⁻¹. Total phenol and flavonoid quantification of the extracts was achieved using Folin-Ciocalteau and AlCl₃ reagents, respectively. The ethyl acetate extract of C. arvensis flowers was the most active in AChE inhibition assay (31.24 ± 1.29%), while the n-hexane extract of C. officinalis leaves exerted the highest ferric ion-chelating capacity (74.27 ± 2.25%). Thin layer chromatographic analysis indicated presence of flavonoid and triterpene derivatives mainly in the extracts.