Effects of Nigella sativa L. seed oil on abnormal semen quality in infertile men: a randomized, double-blind, placebo-controlled clinical trial

ABSTRACT

In recent years, wide utilization of herbal drugs has encouraged scientists to determine their impressive effects on health. Since Nigella sativa L. seed (N. sativa) has many uses including infertility in traditional medicine, the effects of Nigella sativa L. seed oil on abnormal semen quality in infertile men with abnormal semen quality are of interest. This study was conducted on Iranian infertile men with inclusion criteria of abnormal sperm morphology less than 30% or sperm counts below 20 x [10.sup.6]/ml or type A and B motility less than 25% and 50% respectively. The patients in N. sativa oil group (n = 34) received 2.5 ml N. sativa oil and placebo group (n = 34) received 2.5 ml liquid paraffin two times a day orally for 2 months. At baseline and after 2 months, the sperm count, motility and morphology and semen volume, pH and round cells as primary outcomes were determined in both groups. Results showed that sperm count, motility and morphology and semen volume, pH and round cells were improved significantly in N. sativa oil treated group compared with placebo group after 2 months. It is concluded that daily intake of 5 ml N. sativa oil for two months improves abnormal semen quality in infertile men without any adverse effects.

Keywords:

Nigella sativa seed oil

Male infertility

Abnormal semen quality

Traditional medicine

Introduction

Infertility resulting in involuntary childlessness is a social and clinical problem affecting couples worldwide. In a nation-wide study in France infertility was reported in 11% and 24% of couples after 12 and 24 months of unprotected intercourse (Slama et al. 2012). Among infertile couples, male factors, contribute to more than half of all cases of childlessness (Araoye 2003). Infertility does not affect the couples' life only, but it also affects the healthcare services and social environment (Zafar and Mohsin 2001). Several factors such as congenital diseases, hormonal imbalance, genetic and nutritional defects are among disorders in the normal function of testicle which causes men's infertility (Whitman-Elia and Baxley 2001). A number of antioxidants, nutritional therapies, and botanical medicines have proven beneficial in treating male infertility (Sinclair 2000; Agarwal et al. 2008; Chen et al. 1999). N. sativa is a medicinal plant which belongs to the botanical family Ranunculaceae and commonly is known as black seed (Malhotra 2004). N. sativa seed is often used as a spice, food preservative and medicine by people in Asia, Middle East and Africa (Goreja 2003). N. sativa is one of the components of Iranian traditional remedies for treatment of infertility (Salehi Surmaghi 2008). The efficacy of N. sativa oil has been reported on some reproductive traits of male chickens (Samir Bashandy 2007) and male rat's spermatogenesis and fertility (Al-Sa'aidi et al. 2009; Mukhallad et al. 2009; Abdulkarim and Al-Sardary 2009), but no clinical study has been done to investigate the effects of N. sativa oil on infertile men so far. The N. sativa oil has a wide margin of safety (Zaoui et al. 2002) and has been administered to abnormal...