Characterizing Eckol as a Therapeutic Aid: A Systematic Review

Manandhar, Bandana; Paudel, Pradeep; Seong, Su Hui; Jung, Hyun Ah; Choi, Jae Sue

In search of an anti-AD treatment derived from marine plants, the evaluation of the E. bicyclis and its phlorotannins against β-secretase 1 (BACE1) was carried out. Eckol (IC 50 12.20 µM) isolated from EtOAc soluble fraction showed significant activity against BACE1 [51] . Taking into account their potent anti-BACE1 activity, acetylcholinesterase (AChE) and butyryl cholinesterase (BChE) inhibitory assays on ethanolic extracts of 27 Korean seaweeds were evaluated. The ethanolic extract of E. stolonifera yielded n-hexane fraction containing sterols, fucosterol, and 24-hydroperoxy 24-vinylcholesterol, and the EtOAc fraction containing phlorotannins, phloroglucinol, dioxinodehydroeckol, eckol, phlorofucofuroeckol-A, dieckol, triphlorethol-A, 2-phloroeckol, and 7-phloroeckol, where eckol exhibited significant AChE inhibition with an IC 50 value of 20.56 ± 5.61 µM. Conversely, eckol exhibited no inhibitory activity against BChE, with IC 50 values > 500 µM. This difference in activity can be explained by the fact that AChE is a substrate-specific enzyme in nerve synapse, whereas BChE is a non-specific enzyme in plasma and tissue showing involvement of specific binding properties of enzyme and substrate [52] .