Radical Scavenging and Antiacetylcholinesterase Activities of Ethanolic Extracts of Carob, Clove, and Linden.

Acetylcholine (ACh) breaks down in a very short time in diseases related to memory loss. It's a neurotransmitter involved in cholinergic transmission in the brain. Acetylcholinesterase (AChE) hydrolyzes ACh. When AChE is inhibited, the ACh levels increase in the cholinergic synapses. The investigation of natural AChE inhibitors with minimal side effects has become important.Objective • This study intended to determine the total phenolic content, total flavonoid contents, radical scavenging activities, and antiacetylcholinesterase activities of ethanolic extracts of carob pods (ceratonia siliqua), clove buds (eugenia aromatica), and linden flowers (tilia cordata).Design • The research team designed an in-vitro study.Setting • The study took place at a biochemistry research laboratory where purification of enzymes and studies on their kinetic properties and inhibitions are carried out.Outcome measures • The antioxidant properties of the extracts including the total phenolic content (TPC), total flavonoid content (TFC), and free radical scavenging activities, were determined. The AChE enzyme was partially purified by DE-52 anion exchange chromatography from human erythrocytes. Besides, The AChE inhibitory properties of the ethanolic extracts were investigated.Results • The TPCs of the carob pods, clove buds, and linden flowers were 46.78 ± 0.020, 103.57 ± 0.020, and 28.81 ± 0.031, mg GAE/L, respectively. The TFCs were 27.35 ± 0.021, 30.85 ± 0.017, and 32.12 ± 0.022 mg QE/L, respectively. While the extracts of carob pods and linden flowers inhibited AChE, with IC50s of 0.838 mg/ml and 0.156 mg/ml, respectively, clove buds didn't show inhibitory effect.Conclusion • Although the clove buds had the maximum TPC; 1,1-diphenyl-2-picryl hydrazyl (DPPH); and 2,2'-azino-bis [3-ethylbenzothiazoline-6-sulphonic acid] (ABTS+) radical scavenging activity, it didn't show anticholinesterase activity.