title: Neuroprotective effect from stem bark extracts of Knema laurina against H₂O₂- and Aβ(1-42)-induced cell death in human SH-SY5Y cells.
abstract: The stem bark extracts of Knema laurina inhibited the hydrogen peroxide (H2O2)- and aggregated amyloid β-peptide 1-42 length (Aβ(1-42))-induced cell death in differentiated SH-SY5Y cells. Exposure of 250 μM H2O2 or 20 μM Aβ(1-42) to the cells for 24 h reduced 50% of cell viability. Pretreatment of cells with ethyl acetate extract (EAE) or n-butanol extract (BE) at 300 μg/mL and then exposure to H2O2 protected the cells against the neurotoxic effects of H2O2. Besides, methanolic extract (ME) at 1 and 10 μg/mL exerted neuroprotective effect on Aβ(1-42)-induced toxicity to the cells. These results showed that EAE, BE and ME exhibited neuroprotective activities against H2O2- and Aβ(1-42)-induced cell death. Flavonoids (3-6) and β-sitosterol glucoside (8) were isolated from the EAE. Compound 1 was isolated from hexane extract, and compounds 2 and 7 were isolated from dichloromethane extract. All these observations provide the possible evidence for contribution in the neuroprotective effects.
authors.affiliation: a Nutricosmeceuticals and Nutrigenomics Programme, Laboratory of Molecular Biomedicine, Institute of Bioscience, University Putra Malaysia , 43400 UPM Serdang , Selangor , Malaysia.
authors.forename: Norsharina
authors.initials: N
authors.lastname: Ismail
authors.forename: Muhammad Nadeem
authors.initials: MN
authors.lastname: Akhtar
authors.forename: Maznah
authors.initials: M
authors.lastname: Ismail
authors.forename: Seema
authors.initials: S
authors.lastname: Zareen
authors.forename: Syed Adnan Ali
authors.initials: SA
authors.lastname: Shah
authors.forename: Nordin Hj
authors.initials: NH
authors.lastname: Lajis
authors.forename: Saiful N
authors.initials: SN
authors.lastname: Tajuddin
mesh_terms: D016229:Amyloid beta-Peptides / Q000009:adverse effects; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000009:adverse effects; D026324:Myristicaceae / Q000737:chemistry*; D018696:Neuroprotective Agents / Q000737:chemistry*; D010446:Peptide Fragments / Q000009:adverse effects; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D016229:Amyloid beta-Peptides; D018696:Neuroprotective Agents; D010446:Peptide Fragments; D010936:Plant Extracts; C075222:amyloid beta-protein (1-42); D006861:Hydrogen Peroxide
keywords: Aβ1–42; SH-SY5Y cell; flavonoids; hydrogen peroxide; neuroprotective; Knema laurina