title: The effect of fixed oil and water extracts of Nigella sativa on sickle cells: an in vitro study.
abstract: BACKGROUND
  Various drugs have been investigated in the treatment of sickle cell disease (SCD), such as hydroxyurea, piracetam and calcium antagonists. Most of these drugs are potentially toxic and are not suitable for long-term therapy. Recently, Nigella sativa (NS) has been reported to have calcium antagonist and antioxidant activities, both of which play a role in the management of the disease. This study aimed to investigate the in vitro antisickling effect of extracts from NS.
  
  
  METHODS
  Thirty-two patients with SCD, aged 7-47 years old, were recruited for the study. A total of 3 ml of venous blood was collected from each patient and divided into six tubes with heparin. The blood was mixed with 0.5 ml of either 0.1 percent, 0.05 percent or 0.01 percent v/v of the oil extract of NS. A slide was prepared by spreading a drop of treated blood, covered with a cover slide to ensure the complete deoxygenation condition. The separation of irreversibly sickled cells (ISCs) was performed on eight patients by a density gradient (Percoll-Renografin) centrifugation method.
  
  
  RESULTS
  The 0.1 percent v/v concentration of the oil extract of NS resulted in an approximately 80 percent reduction in the formation of sickle cells. The 0.05 percent v/v concentration of NS produced an intermediate effect, while the 0.01 percent v/v concentration had no effect on the formation of sickle cells. The 0.1 percent v/v concentration of the fixed oil of NS led to a considerable reduction in the formation of ISCs.
  
  
  CONCLUSIONS
  The fixed oil extracted from NS seeds has an in vitro antisickling activity.
authors.affiliation: Department of Physiology, College of Medicine, University of Basrah, PO Box 49, Iraq.
authors.forename: N K
authors.initials: NK
authors.lastname: Ibraheem
authors.forename: J H
authors.initials: JH
authors.lastname: Ahmed
authors.forename: M K
authors.initials: MK
authors.lastname: Hassan
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D000975:Antioxidants / Q000627:therapeutic use; D000986:Antisickling Agents / Q000627:therapeutic use; D002648:Child; D016001:Confidence Intervals; D006801:Humans; D008875:Middle Aged; D031881:Nigella sativa / Q000737:chemistry; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D010938:Plant Oils / Q000494:pharmacology* / Q000627:therapeutic use; D014867:Water / Q000494:pharmacology; D055815:Young Adult
chemical_list: D000975:Antioxidants; D000986:Antisickling Agents; D010936:Plant Extracts; D010938:Plant Oils; D014867:Water