title: In vitro antioxidant activity and effect of Parkia biglobosa bark extract on mitochondrial redox status.
abstract: Aqueous-methanolic extract of Parkia biglobosa bark (PBB) was screened for its polyphenolic constituents, in vitro antioxidant activity, and effect on mitochondria redox status. The in vitro antioxidant activity was assessed by using the scavenging abilities and the reducing powers of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) diammonium salt radical cation against Fe(3+). Subsequently, the ability of PBB to inhibit lipid peroxidation induced by FeSO(4) (10 μm) and its metal-chelating potential were investigated. The effects of the extract on basal reactive oxygen species (ROS) generation and on the mitochondrial membrane potential (ΔΨm) in isolated mitochondria were determined by using 2', 7'-dichlorodihydrofluorescin (DCFH) oxidation and safranin fluorescence, respectively. PBB mitigated the Fe(II)-induced lipid peroxidation in rat tissues and showed dose-dependent scavenging of DPPH (IC(50): 98.33 ± 10.0 μg/mL) and ABTS. (trolox equivalent antioxidant concentration, TEAC value = 0.05), with considerable ferric-reducing and moderate metal-chelating abilities. PBB caused slight decreases in both the liver and the brain mitochondria potentials and resulted in a significant decrease (p < 0.001) in DCFH oxidation. Screening for polyphenolics using high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD) revealed the presence of caffeic acid, gallic acid, catechin, epigalocatechin, rutin, and quercetin. These results demonstrate for the first time the considerable in vitro antioxidant activity and favorable effect of PBB on mitochondria redox status and provide justification for the use of the plant in ethnomedicine.
authors.affiliation: Department of Biochemistry, School of Sciences, Federal University of Technology, Akure, Nigeria; Department of Chemistry, Biochemical Toxicology, Federal University of Santa Maria, Santa Maria, Brazil. Electronic address: komokay93@yahoo.com.
authors.forename: Kayode
authors.initials: K
authors.lastname: Komolafe
authors.affiliation: Department of Biochemistry, School of Sciences, Federal University of Technology, Akure, Nigeria.
authors.forename: Tolulope Mary
authors.initials: TM
authors.lastname: Olaleye
authors.affiliation: Department of Molecular Pharmacology and Neuroscience, Nagasaki University, Nagasaki, Japan.
authors.forename: Olaposi Idowu
authors.initials: OI
authors.lastname: Omotuyi
authors.affiliation: Department of Chemistry, Biochemical Toxicology, Federal University of Santa Maria, Santa Maria, Brazil.
authors.forename: Aline Augusti
authors.initials: AA
authors.lastname: Boligon
authors.affiliation: Department of Chemistry, Biochemical Toxicology, Federal University of Santa Maria, Santa Maria, Brazil.
authors.forename: Margareth Linde
authors.initials: ML
authors.lastname: Athayde
authors.affiliation: Department of Biochemistry, School of Sciences, Federal University of Technology, Akure, Nigeria.
authors.forename: Akintunde Afolabi
authors.initials: AA
authors.lastname: Akindahunsi
authors.affiliation: Department of Chemistry, Biochemical Toxicology, Federal University of Santa Maria, Santa Maria, Brazil.
authors.forename: Joao Batista
authors.initials: JB
authors.lastname: Teixeira da Rocha
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D052160:Benzothiazoles / Q000378:metabolism; D001713:Biphenyl Compounds / Q000378:metabolism; D001921:Brain / Q000187:drug effects*; D007887:Fabaceae / Q000737:chemistry*; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects*; D010084:Oxidation-Reduction; D010851:Picrates / Q000378:metabolism; D024301:Plant Bark; D010936:Plant Extracts / Q000494:pharmacology*; D059808:Polyphenols / Q000494:pharmacology*; D017208:Rats, Wistar; D013451:Sulfonic Acids / Q000378:metabolism
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D010851:Picrates; D010936:Plant Extracts; D059808:Polyphenols; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: HPLC; Parkia biglobosa; antioxidant; extract; mitochondria; phenolics