Inhibitory effect of Bryophyllum pinnatum (Lam.) Oken leaf extract and their fractions on α-amylase, α-glucosidase and cholinesterase enzyme

Bryophyllum pinnatum (Lam.) Oken leaves are employed as food and as traditional medicines. This study investigates the antioxidant activity (reducing power, DPPH, ABTS, FRAP, H2O2 scavenging ability and metal ion chelating), carbohydrate digesting enzymes activity and inhibitory activity of cholinergic enzyme of aqueous extract and fractions (n-hexane, ethyl acetate, n-butanol, residual aqueous fraction) of B. pinnatum leaves were investigated. Results showed that aqueous extract of B. pinnatum exhibited DPPH radical scavenging abilities, iron chelation, hydrogen peroxide scavenging abilities and reducing power (Fe³⁺- Fe²⁺). B. pinnatum aqueous extract also had considerably α-amylase and α-glucosidase inhibitory activities with IC₅₀ values 149.20 ± 14.44 μg/mL and 126.15 ± 9.76 μg/mL respectively. Our findings indicated that ethyl acetate fraction contained a considerably higher (p < 0.05) amount of total phenolic, flavonoids, total antioxidant, FRAP, metal ion, ABTS and DPPH radical scavenging activity than other solvent fractions. Furthermore, the ethyl acetate fraction elicited a significantly higher (p < 0.05) inhibitory effects on α-glucosidase (IC₅₀ = 70.90 ± 1.23 μg/ml), α-amylase (IC₅₀ = 62.45 ± 1.22 μg/ml), acetylcholinesterase (AChE) (IC₅₀ = 66.75 μg/mL) and butyrylcholinesterase (BChE) (IC₅₀ = 62.97 μg/mL) activities than other fractions. Hence, B. pinnatum leaves were rich in biologically active components; thus, could be employed to formulate new plant-based pharmaceutical and nutraceutical drugs to improve human health.