Neuroprotective effect of the marine macroalgaGelidiella acerosa: identification of active compounds through bioactivity-guided fractionation

Abstract

Context Gelidiella acerosa (Forsskål) Feldmann & G. Hamel (Rhodophyta-Gelidiales) is a marine red macroalga. Our previous work found that a benzene extract of G. acerosa possesses noticeable neuroprotective activity, when evaluated through in vitro and in vivo systems. Objective Bioactive-guided fractionation and identification of active compounds by column chromatography using solvents of varying polarity. Materials and methods Fractionation was done by column chromatography, antioxidant and anticholinesterase activity was assessed by DPPH and cholinesterase inhibition assays (50-200 mg/ml), compound identification was done by LC-MS analysis, the mode of interaction of active compound was analyzed through docking studies and quantification was done by highperformance thin-layer chromatography (HPTLC) analysis.Results The results suggest that fractions F9-F13 exhibited significant (p50.05) antioxidant and anticholinesterase activities. Hence, these fractions were pooled together and verified for neuroprotective activity. The pooled fraction was subjected to LC-MS analysis and among all the compounds, phytol was previously reported to possess excellent neuroprotective potential. Hence, the neuroprotective potential of phytol was assessed. The results suggest that phytol showed significant (p50.05) antioxidant activities (25-125 mg/ml) with an IC 50 value of 95.27 ± 1.65 mg/ml and cholinesterase inhibitory potential (5-25 mg/ml) with IC 50 values of 2.704 ± 0.07 and 5.798 ± 0.72 mg/ml for AChE and BuChE, respectively. Molecular docking studies suggest that phytol interacts with cholinesterase through the arginine residue of the enzyme. HPTLC quantification showed that about 6.266 mg of phytol was present per mg of pooled fraction. Conclusion The study suggests that phytol might act as the key compound in contributing to the neuroprotective potential of G. acerosa. ARTICLE HISTORY

Gelidiella acerosa protects against Aβ 25–35-induced toxicity and memory impairment in Swiss Albino mice: an in vivo report

“…Moreover, recent studies from our group revealed that bioactive-guided fractionation revealed the presence of diterpene, phytol, which was further confirmed through molecular docking studies (Syad et al. 2016 ). With this background information, in the present study, the neuroprotective effect of G. acerosa benzene extract was evaluated on Aβ 25–35-treated albino mice.…”

Current Trends on Seaweeds: Looking at Chemical Composition, Phytopharmacology, and Cosmetic Applications

“…Fucosterol isolated from the marine algae Pelvetia siliquosa and dieckol were also found to reduce oxidative stress in vivo by significantly increasing the free radical scavenging enzyme activities and the activity of hepatic antioxidant enzymes such as glutathione peroxidase and superoxide dismutase [276,277]. Similar anti-cancer and neuroprotective activities have been reported for phytols present in the marine red alga Gelidiella acerosa [284,304].…”

Potential Application of Prunus armeniaca L. and P. domestica L. Leaf Essential Oils as Antioxidant and of Cholinesterases Inhibitors

“…Similar results were obtained with Trolox, used as a positive control. Syad et al [22] showed an IC 50 value for phytol of 95.27 μg/mL in the DPPH test. The same research group analysed the potential cholinesterases’ inhibitory activity of this diterpene.…”