The main volatile oils of black seed (thymoquinon, dithymoquinone, thymohydroquinone and thymol) have been reported to reduce the 3-hydroxy-3-methyl-glutaryl-CoA reductase (key enzyme in cholesterol synthesis regulation) in the liver (El-Dakhakhny et al., 2000). The lower of de novo cholesterol synthesis has been reported to increase the expression of low-density lipoprotein receptors on hepatocytes, resulting in higher LDL uptake by the liver hepatocytes and ultimately lower blood LDL-C concentration