Characterizing Eckol as a Therapeutic Aid: A Systematic Review

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

y, the antithrombotic activity of eckol [77] also supports the possibility of developing eckol as an anticoagulant. The antihypertensive effect of eckol was attributed to ACE-inhibition, and the closed-ring dibenzo-1,4-dioxane was crucial for the inhibition [28] . Still in vivo study is a requisite for establishing eckol as a pharmaceutical product. Furthermore, following the success in characterizing eckol as an anticancer agent via in vitro cell-based studies [75, 76] , eckol could further be tested in vivo to establish its full potential against this life-threatening disease. Several contraindications of eckol being less active [19, 73] or inactive [74] against the allergic symptoms are reported. The compounds (fucodiphloroethol G, phlorofucofuroeckol A, dieckol, 8,8 -bieckol) other than eckol showed more potent activity, and all of them have the basic skeleton of eckol which could have a crucial role for antiallergic activity. So it is worth confirming the antiallergic property of eckol in vivo. In terms of the antiviral and antibacterial activity, eckol showed eminent results [29, 67, 124] , but the production of proinflammatory cytokines in response to the antiviral activity of extract containing eckol was a contraindicatory point [67] . Even though the increase in pro-inflammatory cytokines may lead to inflammation, the subsequent basal expression levels of these cytokines after a significant increase in the early stage of an oral administration of extract indicate the immunomodulatory activity of the extract. Hence, the extract activated the anti-inflammatory response or suppressed the pro-inflammatory cytokines to control the extent of inflammatory condition. Eckol exhibiting a potent anti-inflammatory activity is a point to be noted, but the introduction of the dimers and isomers of eckol have surpassed the activity of eckol and have appeared to be more potent. Even though they are potent, the geometry of the aromatic ring and main configuration of the eckol skeleton is always critical for the suppressive property. The cell-based experiments related to tyrosinase inhibition by eckol could also be beneficial as future references for experiments on the living subjects. The potent anti-hyperlipidemic activity of eckol compared to probucol [81] and the suppression of high lipid levels in serum of hyperlipidemic rats [80] could be evidence to develop it as a pharmaceutical agent against hyperlipidemia. The anti-hair loss [149] and anti-hearing loss [150] activities of eckol show that it still holds potential in several unidentified fields other than ones that are stated in this review. Hence, a continuous evaluation of eckol in the future is important to increase its spectrum of activity.