The radioprotective effect of Nigella sativa on nitrosative stress in lens tissue in radiation-induced cataract in rat

Abstract

Objective: The aim of this study was to investigate the antioxidant and radioprotective effects of Nigella sativa oil (NSO) and thymoquinone (TQ) against ionizing radiation-induced cataracts in lens after total cranium irradiation (IR) of rats with a single dose of 5 gray (Gy).

Materials and methods: Seventy-four Sprague-Dawley rats were used for the experiment. The rats were randomly divided into six groups. Group A received total cranium IR plus NSO (1 g kg^–1 d^–1) orally through an orogastric tube. Group B received total cranium IR plus TQ (50 mgkg^–1 d^–1) daily by intraperitoneal injection. Group C received 5 Gy of gamma IR as a single dose to total cranium plus 1 ml saline. Group D₁ just received 1 ml saline. Group D₂ just received dimethyl sulfoxide. Group D₃ did not receive anything.

Results: At the end of the 10th d, cataract developed in 80% of the rats in IR group only. After IR, cataract rate dropped to 20% and 50% in groups which were treated with NSO and TQ, respectively, and was limited at grades 1 and 2. Nitric oxide synthase activity, nitric oxide and peroxynitrite levels in the radiotherapy group were higher than those of all other groups.

Conclusions: The results implicate a major role for NSO and TQ in preventing cataractogenesis in ionizing radiation-induced cataracts in the lenses of rats, wherein NSO were found to be more potent.

• Cataract
• free radical
• irradiation
• Nigella sativa
• nitric oxide
• nitrosative stress

Declaration of interest

The authors report no declarations of interest. None of the authors has a commercial interest, financial interest and/or other relationship with manufacturers of pharmaceuticals, laboratory supplies and/or medical devices or with commercial providers of medically related services.