title: Water fraction of edible medicinal fern Stenochlaena palustris is a potent α-glucosidase inhibitor with concurrent antioxidant activity.
abstract: This study aimed to isolate a potent antiglucosidase and antioxidant fraction from Stenochlaena palustris. Extraction was performed with hexane, chloroform, ethyl acetate, methanol, and water. Antiglucosidase, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and ferric reducing antioxidant power (FRAP) assays found methanol extract (ME) to be the most active. Water fraction (WF) of ME was a stronger α-glucosidase inhibitor (EC50 2.9 μg/mL) than quercetin, with weak antiamylase activity. WF was a competitive α-glucosidase inhibitor. DPPH scavenging activity of WF (EC50 7.7 μg/mL) was weaker than quercetin. WF (EC50 364 μg/mL) was a stronger hydrogen peroxide scavenger than gallic acid (EC50 838 μg/mL) and was equally strong as quercetin in scavenging superoxide. WF possessed moderate copper chelating activity. WF was enriched in total phenolics (TP) and hydroxycinnamic acids (THC). TP correlated with antioxidant activity (R(2) > 0.76). Only THC correlated with antiglucosidase activity (R(2) = 0.86). Overall, WF demonstrated concurrent, potent antiglucosidase and antioxidant activities.
authors.affiliation: Center for Biodiversity Research, Universiti Tunku Abdul Rahman, 31900 Kampar, Malaysia; Department of Chemical Science, Faculty of Science, Universiti Tunku Abdul Rahman, 31900 Kampar, Malaysia. Electronic address: chaitt@utar.edu.my.
authors.forename: Tsun-Thai
authors.initials: TT
authors.lastname: Chai
authors.affiliation: Department of Chemical Science, Faculty of Science, Universiti Tunku Abdul Rahman, 31900 Kampar, Malaysia.
authors.forename: Meng-Tee
authors.initials: MT
authors.lastname: Kwek
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Hean-Chooi
authors.initials: HC
authors.lastname: Ong
authors.affiliation: Center for Biodiversity Research, Universiti Tunku Abdul Rahman, 31900 Kampar, Malaysia; Department of Chemical Science, Faculty of Science, Universiti Tunku Abdul Rahman, 31900 Kampar, Malaysia.
authors.forename: Fai-Chu
authors.initials: FC
authors.lastname: Wong
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D003373:Coumaric Acids / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000737:chemistry; D029624:Ferns / Q000737:chemistry*; D005504:Food Analysis; D005707:Gallic Acid / Q000737:chemistry; D065089:Glycoside Hydrolase Inhibitors / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry; D011794:Quercetin / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000975:Antioxidants; D003373:Coumaric Acids; D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D010936:Plant Extracts; D059808:Polyphenols; D012997:Solvents; D014867:Water; D005707:Gallic Acid; D003300:Copper; D011794:Quercetin; D006861:Hydrogen Peroxide
keywords: Antiglucosidase; Antioxidant; Fern; Phytochemical; Solvent fractionation; Stenochlaena palustris