KIDNEY DISEASES 142 Original Paper Iranian Journal of Kidney Diseases | Volume 11 | Number 2 | March 2017 Protective Effect of Thymoquinone Against Morphine Injuries to Kidneys of Mice Cyrus Jalili, 1 Mohammad Reza Salahshoor, 2 Mohsen Hoseini, 3 Shiva Roshankhah, 2 Maryam Sohrabi, 2 Ahmad Shabanizadeh 4,5 Introduction. Thymoquinone is a phytochemical compound found in the plant Nigella sativa. It has various pharmacological effects such as antioxidant and anti-apoptotic. Morphine can increase the generation of free radicals. It is mainly excreted through the kidneys and causes disturbing effects. This study was designed to evaluate protective effects of thymoquinone against morphine- induced damages to the kidneys of mice. Materials and Methods. Various doses of thymoquinone (4.5 mg/ kg, 9 mg/kg, and 18 mg/kg) were intraperitoneally administered along with morphine to 48 male mice for 20 consequent days. These mice were compared with a control group with saline injection, morphine group, and groups with same doses of thymoquinone only (n = 6 in each group). Blood urea nitrogen, serum creatinine, and serum nitric oxide levels, as well kidney weight and histology were assessed after the interventions. Results. Morphine administration significantly decreased kidney weight and the number and mean diameter of the glomeruli. Increased levels of blood urea nitrogen, serum creatinine, and serum nitric oxide were also noted with morphine compared to the control group (P < .05). However, administration of thymoquinone and thymoquinone plus morphine significantly enhanced kidney weight, number and mean diameter of the glomeruli. All of the groups with thymoquinone were also associated with reduced blood urea nitrogen, serum creatinine, and serum nitric oxide levels compared to the morphine group (P < .05). Conclusions. It seems that antioxidant and anti-apoptotic effects of thymoquinone could protect of the kidneys against damage due to morphine toxicity. IJKD 2017;11:142-50 www.ijkd.org 1 Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran 2 Department of Anatomical Sciences, Medical School, Kermanshah University of Medical Sciences, Kermanshah, Iran 3 Students Research Committee, Kermanshah University of Medical Sciences, Kermanshah, Iran 4 Department of Anatomical Sciences, Medical School, Rafsanjan University of Medical Sciences, Rafsanjan, Iran 5 Immunology of Infectious Diseases Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran Keywords. thymoquinone, kidney injury, morphine, mice INTRODUCTION Study of compounds with plant origin is a very interesting branch of medical sciences. Many of these compounds have preventive effects, and as drugs with potentially fewer side effects and numerous properties, can be used to prevent certain diseases. 1 This property is often due to the presence of antioxidants in the plants, which prevent injuries associated with the free radicals. 2 The extract of thymoquinone has anticonvulsant and antioxidant properties and is able to collect free radicals. 3 Thymoquinone, scientifically known as Nigella sativa L, is a family of Ranunculaceae with white or pale blue color, which is turned black when exposed to air. 4 Nigella sativa has antioxidative,