title: Polychlorinated biphenyls impair blood-brain barrier integrity via disruption of tight junction proteins in cerebrum, cerebellum and hippocampus of female Wistar rats: neuropotential role of quercetin.
abstract: Polychlorinated biphenyls (PCBs) comprise a ubiquitous class of toxic substances associated with carcinogenic and tumor-promoting effects as well as neurotoxic properties. Reactive oxygen species, which is produced from PCBs, alters blood-brain barrier (BBB) integrity, which is paralleled by cytoskeletal rearrangements and redistribution and disappearance of tight junction proteins (TJPs) like claudin-5 and occludin. Quercetin, a potent antioxidant present in onion and other vegetables, appears to protect brain cells against oxidative stress, a tissue-damaging process associated with Alzheimer's and other neurodegenerative disorders. The aim of this study is to analyze the role of quercetin on oxidative stress markers and transcription of transmembrane and cytoplasmic accessory TJPs on cerebrum, cerebellum and hippocampus of female rats exposed to PCBs. Rats were divided into the following four groups. Group I: received only vehicle (corn oil) intraperitoneally (i.p.); group II: received Aroclor 1254 at a dose of 2 mg/kg body weight (bwt)/day (i.p); group III: received Aroclor 1254 (i.p.) and simultaneously quercetin 50 mg/kg bwt/day through gavage and group IV: received quercetin alone gavage. From the experiment, the levels of hydrogen peroxide, lipid peroxidation and thiobarbituric acid reactive substances were observed to increase significantly in cerebrum, cerebellum and hippocampus as 50%, 25% and 20%, respectively, after exposure to PCB, and the messenger RNA expression of TJP in rats exposed to PCBs is decreased and is retrieved to the normal level simultaneously in quercetin-treated rats. Hence, quercetin can be used as a preventive medicine to PCBs exposure and prevents neurodegenerative disorders.
authors.affiliation: Department of Endocrinology, Dr ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Chennai, India.
authors.forename: K
authors.initials: K
authors.lastname: Selvakumar
authors.forename: R Lakshmi
authors.initials: RL
authors.lastname: Prabha
authors.forename: K
authors.initials: K
authors.lastname: Saranya
authors.forename: S
authors.initials: S
authors.lastname: Bavithra
authors.forename: G
authors.initials: G
authors.lastname: Krishnamoorthy
authors.forename: J
authors.initials: J
authors.lastname: Arunakaran
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D018696:Neuroprotective Agents / Q000494:pharmacology*; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D011794:Quercetin / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D062725:Tight Junction Proteins / Q000235:genetics
chemical_list: D004785:Environmental Pollutants; D018696:Neuroprotective Agents; D012333:RNA, Messenger; D017392:Thiobarbituric Acid Reactive Substances; D062725:Tight Junction Proteins; D011794:Quercetin; D006861:Hydrogen Peroxide; D011078:Polychlorinated Biphenyls