RESEARCH ARTICLE The effects of Nigella sativa on quality of life, disease activity index, and some of inflammatory and oxidative stress factors in patients with ulcerative colitis Mehrnaz Nikkhah‐Bodaghi 1 | Zahra Darabi 1 | Shahram Agah 2 | Azita Hekmatdoost 3 1 Student Research Committee, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2 Colorectal Research Center, Iran University of Medical Sciences, Tehran, Iran 3 Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran Correspondence Dr. Azita Hekmatdoost, Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Email: a_hekmat2000@yahoo.com; azita. hekmatdoost@cw.bc.ca Funding information Student Research Committee of Shahid Beheshti University of Medical Science; Stu- dent Research Committee of Shahid Beheshti University of Medical Science, Tehran, Iran The aim of this study was to evaluate the effects of Nigella sativa (NS) supplementa- tion in patients with ulcerative colitis. Two grams of NS powder or placebo were con- sumed for 6 weeks by 46 patients with active mild to moderate ulcerative colitis. Using valid and common questionnaires of colitis severity and blood sampling, we estimated disease activity index, quality of life, and some of inflammatory and oxida- tive stress factors at baseline and after 6 weeks of supplementation. NS‐elevated tumor necrosis factor‐alpha and high‐sensitivity‐c‐reactive‐protein as well as reduced malondialdehyde (p = 0.01, p = 0.02, and p = 0.005, respectively) compared with placebo. There was no significant difference between the two groups in serum total antioxidant capacity and nuclear factor kB levels. Total scores of Simple Clinical Colitis Activity Index Questionnaire and Inflammatory Bowel Disease Questionnaire‐9 were not different between the two groups; however, stool frequency score decreased significantly in NS group. Further clinical trials with different pattern of NS administration (the amount of total and divided daily doses, either powder type or standard extracts/oil and different time arrangement) are needed to clarify the vision. KEYWORDS IBDQ‐9, inflammatory factors, Nigella sativa, oxidative stress, SCCIAQ, ulcerative colitis 1 | INTRODUCTION Ulcerative colitis (UC) is a life‐long idiopathic bowel disorder, which is accompanied by cyclic attacks of rectal bleeding, diarrhea, bloating, and abdominal cramp. In active phase of the disease, it obviously attenuates quality of patients' life, and imposes extensive societal and medical burden (Faghfoori et al., 2011; Isik et al., 2011; Kawalec & Stawowczyk, 2018). The highest rate of UC is reported from west- ern countries; however, its prevalence has been growing rapidly in developing countries during recent years (Rashvand, Somi, Rashidkhani, & Hekmatdoost, 2015b). It seems that elevated produc- tion of proinflammatory mediators develops oxidative stress in the bowel under circumstances of adverse interactions between environ- mental factors, intestinal flora, and genetic susceptibilities during UC development (El‐Abhar, Hammad, & Gawad, 2008). Therapeutic strat- egies for UC including anti‐inflammatory and immunosuppressive agents only reduce symptoms and prolong the relief time as well as make affluent side effects, which limits their therapeutic value (Colitis–Pathophysiology, 2003; Mowat et al., 2011). Investigating for complementary therapies with low prices and high efficacy is con- sidered as a novel achievement for disease management. Modified diet and dietary supplements are the most amendable environmental factors involved in pathogenesis of UC, which have been shown to improve symptoms and inflammatory and oxidative status of patients (Rashvand et al., 2015b; Rashvand, Somi, Rashidkhani, & Hekmatdoost, 2015a; Samsami‐Kor, Daryani, Asl, & Hekmatdoost, 2015). Nigella sativa (NS) accrues to Ranunculaceae family (Namazi, Larijani, Ayati, & Abdollahi, 2018). Effects of NS have been found in hypercholesterolemia, diabetes, cancer, inflammation, gastrointestinal disorders, hypertension, and nasal mucosa symptoms due to aging and rheumatoid arthritis (Gheita & Kenawy, 2012; Kaatabi et al., Received: 16 September 2018 Revised: 8 November 2018 Accepted: 28 December 2018 DOI: 10.1002/ptr.6296 Phytotherapy Research. 2019;1–6. © 2019 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/ptr 1