Ameliorative effects of Nigella sativa on dyslipidemia

Introduction Dyslipidemia is an established risk factor for ischemic heart disease. Nigella sativa ( NS ) is a medicinal plant that has been used for the treatment and prevention of a variety of diseases, in particular hyperlipidemia. Methods We reviewed the existing literature published until 2014 by using the following keywords: ‘‘ Nigella sativa ’’, ‘‘black cumin’’, ‘‘black seeds’’, ‘‘thymoquinone’’, and ‘‘lipid’’. Results In the conducted studies, different preparations of NS including seed powder (100 mg–20 g daily), seed oil (20–800 mg daily), thymoquinone (3.5–20 mg daily), and seed extract (methanolic extract especially), were shown to reduce plasma levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C) and triglycerides, but the effect on high-density lipoprotein cholesterol (HDL-C) was not significant. NS and thymoquinone have been reported to be safe and well tolerated with no severe adverse effect. In clinical trials, NS was found to be effective when added as adjunct to standard antihyperlipidemic and antidiabetic medications. Lipid-modifying effects of NS could be attributed to the inhibition of intestinal cholesterol absorption, decreased hepatic cholesterol synthesis, and up-regulation of LDL receptors. Conclusions Overall, the evidence from experimental and a clinical studies suggests that NS seeds are a promising natural therapy for dyslipidemic patients.