Experimental antithrombotic effects of sesame seed whole grains and extracts.

Prevention of arterial thrombotic diseases has a high priority in developed countries. An inappropriate diet is known to enhance the risks for acute thrombotic events, and nutritional products experimentally shown to be antithrombotic, might contribute beneficial effects. The present study forms part of a series of investigations into the antithrombotic effect of various foods and vegetables. Roasted and crushed whole grains from six varieties of sesame seeds were added to the diet of mice. Antithrombotic activity was measured in the carotid artery in vivo, using a He-Ne laser-induced thrombosis technique after 12 weeks. Col/Chichibu/Maruteru-2/1995 and T016 varieties showed significant antithrombotic activity, whilst 00037803 was prothrombotic. The acute effects of purified ingredients, sesamin, sesamolin and sesamol, given orally or intra-arterially, were also examined after a single dose. The most effective ingredient was sesamol, followed by sesamolin and sesamin. Daily intake of specific antithrombotic sesame whole grains or purified active ingredients might help to prevent atherothrombotic diseases.

Lipid metabolism and nutrigenomics - impact of sesame lignans on gene expression profiles and fatty acid oxidation in rat liver.

The impact of sesamin, episesamin and sesamolin (sesame lignans) on hepatic gene expression profiles was compared with a DNA microarray. Male Sprague-Dawley rats were fed experimental diets containing 0.2% sesamin, episesamin or sesamolin, and a control diet free of lignans for 15 days. Compared to a lignan-free diet, a diet containing sesamin, episesamin and sesamolin caused more than 1.5- and 2-fold changes in the expression of 128 and 40, 526 and 152, and 516 and 140 genes, respectively. The lignans modified the mRNA levels of not only many enzymes involved in hepatic fatty acid oxidation, but also proteins involved in the transportation of fatty acids into hepatocytes and their organelles, and in the regulation of hepatic concentrations of carnitine, CoA and malonyl-CoA. It is apparent that sesame lignans stimulate hepatic fatty acid oxidation by affecting the gene expression of various proteins regulating hepatic fatty acid metabolism. The changes in the gene expression were generally greater with episesamin and sesamolin than with sesamin. In terms of amounts accumulated in serum and the liver, the lignans ranked in the order sesamolin, episesamin and sesamin. The differences in bioavailability among these lignans appear to be important to their divergent physiological activities. We also confirmed that dietary sesame seed affected the expression of genes related to fatty acid oxidation in a manner similar to isolated lignan compounds.

Assessment of genetic diversity in sesame ( Sesamum indicum L. ) detected by Amplified Fragment Length Polymorphism markers

Sesame (Sesamum indicum L.) is one of the oldest oil crops and is widely cultivated in Asia and Africa. To determine the level of genetic diversity in relation to geographical origins and morphological characteristics, a total of 96 accessions have been collected from different parts of the world and were analyzed using AFLP techniques. Twenty-one primer pairs generated a total of 445 bands and among them 157 (35 percent) were polymorphic. Using UPGMA clustering analysis method based on the similarity coefficient, accessions were separated into two major groups. The first group mostly consists of Eastern Asian origin and another group consists of South Asian origin. Sub-clusters separated the accessions and form distinct diversity among groups. Considering the relatednessof accessions, geographical origin and their morphological characteristics are reflected to the similarity of AFLP pattern.

Formation of two methylenedioxy bridges by a Sesamum CYP81Q protein yielding a furofuran lignan, (+)-sesamin.

(+)-Sesamin, a furofuran class lignan, is widespread in vascular plants and represented by Sesamum spp. (+)-Sesamin has been of rapidly growing interest because of its beneficial biological effects in mammals, but its biosynthesis and physiological roles in plants remain to be clarified. It is speculated to be synthesized from (+)-pinoresinol by means of (+)-piperitol by formation of two methylenedioxy bridges mediated by two distinct Sesamum indicum cytochrome P450 (SiP450) proteins. Here, we report an SiP450, CYP81Q1, that alone catalyzes (+)-sesamin biosynthesis from (+)-pinoresinol by means of (+)-piperitol by forming two methylenedioxy bridges. The CYP81Q1 gene expression profile was temporally consistent with the accumulation pattern of (+)-sesamin during seed development. The CYP81Q1-GFP chimera protein was colocalized with an endoplasmic reticulum (ER)-targeting chimera protein, indicating that (+)-sesamin biosynthesis occurs on the ER cytoplasmic surface. Moreover, we isolated two CYP81Q1 homologs from other Sesamum spp. Sesamum radiatum CYP81Q2 showed dual (+)-piperitol/(+)-sesamin synthetic activity. CYP81Q2, as well as CYP81Q1, therefore, corresponds to a (+)-piperitol/(+)-sesamin synthase in lignan biosynthesis. In contrast, Sesamum alatum CYP81Q3 showed no activity, in accord with (+)-sesamin being deficient in S. alatum. Our findings not only provide insight into lignan biosynthesis but also unravel a unique mode of cytochrome P450 action.