title: Preclinical and clinical effects of Nigella sativa and its constituent, thymoquinone: A review.
abstract: BACKGROUND
  Nigella sativa (N. sativa) L. (Ranunculaceae), well known as black cumin, has been used as a herbal medicine that has a rich historical background. It has been traditionally and clinically used in the treatment of several diseases. Many reviews have investigated this valuable plant, but none of them focused on its clinical effects. Therefore, the aim of the present review is to provide a comprehensive report of clinical studies on N. sativa and some of its constituents.
  
  
  METHODS
  Studies on the clinical effects of N. sativa and its main constituent, thymoquinone, which were published between 1979 and 2015, were searched using various databases.
  
  
  CONCLUSIONS
  During the last three decades, several in vivo and in vitro animal studies revealed the pharmacological properties of the plant, including its antioxidant, antibacterial, antiproliferative, proapoptotic, anti-inflammatory, and antiepileptic properties, and its effect on improvement in atherogenesis, endothelial dysfunction, glucose metabolism, lipid profile dysfunction, and prevention of hippocampus pyramidal cell loss. In clinical studies, antimicrobial, antioxidant, anti-inflammatory, antitumor, and antidiabetic properties as well as therapeutic effects on metabolic syndrome, and gastrointestinal, neuronal, cardiovascular, respiratory, urinary, and reproductive disorders were found in N. sativa and its constituents.
  
  
  CONCLUSIONS
  Extensive basic and clinical studies on N. sativa seed powder, oil, extracts (aqueous, ethanolic, and methanolic), and thymoquinone showed valuable therapeutic effects on different disorders with a wide range of safe doses. However, there were some confounding factors in the reviewed clinical trials, and a few of them presented data about the phytochemical composition of the plant. Therefore, a more standard clinical trial with N. sativa supplementation is needed for the plant to be used as an inexpensive potential biological adjuvant therapy.
authors.affiliation: Neurogenic Inflammation Research Centre, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Gholamnezhad
authors.affiliation: School of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran.
authors.forename: Shahrzad
authors.initials: S
authors.lastname: Havakhah
authors.affiliation: Neurogenic Inflammation Research Centre, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address: boskabadymh@mums.ac.ir.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Boskabady
mesh_terms: D000818:Animals; D016227:Benzoquinones / Q000009:adverse effects / Q000737:chemistry / Q000302:isolation & purification / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D020834:Ethnopharmacology; D006801:Humans; D031881:Nigella sativa / Q000737:chemistry*; D008517:Phytotherapy; D010936:Plant Extracts / Q000009:adverse effects / Q000737:chemistry / Q000302:isolation & purification / Q000627:therapeutic use*; D010946:Plants, Medicinal; D018570:Risk Assessment; D012639:Seeds / Q000737:chemistry; D018675:Toxicity Tests
chemical_list: D016227:Benzoquinones; D010936:Plant Extracts; C003466:thymoquinone
keywords: 4-terpineol (PubChem CID: 11230); Antidiabetic; Antitumor; Cardioprotective; Clinical effects; Gastroprotective; Hepatoprotective; Neuroprotective; Nigella sativa; Pulmonary protective; Thymoquinone; Thymoquinone (PubChem CID: 10281); alpha-hederin (PubChem CID: 71464054); alpha-pinene (PubChem CID: 6654); carvacrol (PubChem CID: 10364); dithymoquinone or nigellone (PubChem CID: 398941); kaempferol glucoside (PubChem CID: 12358425); p-cymene (PubChem CID: 7463); thymol (PubChem CID: 6989); trans-anethol (PubChem CID: 637563)