title: Hepatoprotective efficacy of Nigella sativa seeds dietary supplementation against lead acetate-induced oxidative damage in rabbit - Purification and characterization of glutathione peroxidase.
abstract: Lead (Pb) is a toxic ubiquitous environmental pollutant that induces hepatotoxicity in both animals and humans. The ability of Nigella saliva seeds (NSS) in ameliorating lead acetate (PbAc)-induced hepatic oxidative damage was investigated using a rabbit model. Forty New Zealand rabbits were given feed and water ad libitum. They were allocated randomly into four groups: control; PbAc (5g/L drinking water); NSS (20g/kg diet) and NSS+PbAc groups. After two months, liver samples were collected and analyzed for malondialdehyde (MDA), glutathione (GSH), glutathione S-transferase (GST) and glutathione peroxidase (GPx) contents. Purification and characterization of GPx were also evaluated. PbAc exposure significantly (p<0.05) increased MDA (lipid peroxidation biomarker) and reduced the GSH levels and the GST and GPx activities. Concurrently supplemented NSS significantly (p<0.05) decreased MDA levels and restored the GSH, GST, and GPx contents successfully. Electrophoretically, the homogeneous GPx preparation from the liver had a specific activity of 30.44 U/mg protein and a yield of 1.31%. The Kmvalues for cumene hydroperoxide were 4.76μM in control, PbAc and NSS+PbAc groups, and 4.09μM in NSS group. The GPx reaction had a temperature optimum 40°C, pH optimum 8 and molecular weight 21 kDa. The obtained data indicated the potent efficacy of NSS against PbAc-induced oxidative stress; that was mediated through induction and activation of antioxidants, particularly GPx and scavenging free radicals. Moreover, the purified hepatic GPx is characterized as a selenoprotein (Se-GPx).
authors.affiliation: Department of Biochemistry, Faculty of Veterinary Medicine, Veterinary Medicine, Damanhour University, Damanhour, 22511, Egypt. Electronic address: ali.elfar@damanhour.edu.eg.
authors.forename: Ali H
authors.initials: AH
authors.lastname: El-Far
authors.affiliation: Department of Biochemistry, Faculty of Veterinary Medicine, Alexandria University, Edfina, 22758, Egypt. Electronic address: profkorshom@yahoo.com.
authors.forename: Mahdy A
authors.initials: MA
authors.lastname: Korshom
authors.affiliation: Department of Biochemistry, Faculty of Veterinary Medicine, Alexandria University, Edfina, 22758, Egypt. Electronic address: abdmand@yahoo.com.
authors.forename: Abdelwahab A
authors.initials: AA
authors.lastname: Mandour
authors.affiliation: Department of Biochemistry, Faculty of Science, Alexandria University, Alexandria, Egypt. Electronic address: ashraf.elbasomy@alexu.edu.eg.
authors.forename: Ashraf A
authors.initials: AA
authors.lastname: El-Bessoumy
authors.affiliation: Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511, Egypt. Electronic address: elsayed-ys@vetmed.dmu.edu.eg.
authors.forename: Yasser S
authors.initials: YS
authors.lastname: El-Sayed
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D056486:Chemical and Drug Induced Liver Injury / Q000517:prevention & control*; D004032:Diet; D019587:Dietary Supplements; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D031881:Nigella sativa / Q000737:chemistry*; D009942:Organometallic Compounds / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D020011:Protective Agents / Q000494:pharmacology*; D011817:Rabbits; D012639:Seeds / Q000737:chemistry
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D009942:Organometallic Compounds; D010936:Plant Extracts; D020011:Protective Agents; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D005978:Glutathione; C008261:lead acetate
keywords: Antioxidants; Enzyme purification; Lead toxicity; Nigella sativa; Oxidative stress; Protein expression