Effects of black seeds (Nigella sativa) on male infertility: A systematic review

Following an increase in free radicals, DNA damage and lipid peroxidation in human sperm may occur. Antioxidant components in medicinal herbs such as Nigella sativa (NS) have been indicated to improve spermatogenesis and steroidogenesis. The aim of the present study was to conduct a systemic review summarizing the effects of NS on male infertility. A number of electronic databases were searched namely Pubmed, Science Direct, Google scholar and Springer from the period January 2000 until June 2014. Searching was limited to articles in the English language. Patents and abstracts from symposiums and congress were excluded because they contained insufficient information for evaluation and comparison with other studies. The outcome of this study indicated that NS can positively influence sperm parameters, semen, Leydig cells, reproductive organs and sexual hormones. The main potential mechanism is through the antioxidant properties of NS. Thymoquinone (TQ) and unsaturated fatty acids are the main antioxidant components of NS. NS and TQ derived from NS can improve male fertility parameters through promoting antioxidant defence. Although the findings of this review suggest that NS is a good candidate for male infertility treatment, there is insufficient evidence to make recommendations for its use as an adjunct therapy in infertile men. More clinical trials are recommended to demonstrate the efficacy of NS on male infertility.