Sesame Lignans

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The observation that sesame oil could decrease the production of arachidonic acid in fungi and rat liver cells led to the identification of the sesame lignans (sesamin, sesamolin, sesaminol) as specific inhibitors of Δ5 desaturase (delta-5-desaturase), one of the enzymes used in the synthesis of arachidonic acid.

By inhibiting Δ5 desaturase, sesame lignans may reduce the synthesis of pro-inflammatory prostaglandin, leukotrienes, and thromboxanes, each of which require arachidonic acid as a starting material.

In animal models, diets high in sesame seed oil reduced production of the pro-inflammatory prostaglandins PGE-1 and -2, as well as thromboxane B2. In humans, 5 weeks of sesamin supplementation (39 mg/day) reduced the production of the pro-inflammatory vasoconstrictor 20-hydroxyeicosatetraenoic acid (20-HETE; a product of the enzyme 5-LOX) by 30%.

This potential anti-inflammatory property of sesame lignans may partially explain its observed hypotensive (blood pressure-lowering) activity.

Sesame Seeds (via their Sesamin content) may inhibit Delta-5 Desaturase (the enzyme that catalyzes the conversion of Gamma-Linolenic Acid (GLA) into Arachidonic Acid; however: Delta-5 Desaturase also catalyzes the (desirable) conversion of Eicosatetraenoic Acid (ETA) to Eicosapentaenoic Acid (EPA).


References:

Chavali, S. R., et al. Dietary alpha-linolenic acid increases TNF-alpha, and decreases IL-6, IL-10 in response to LPS: effects of sesamin on the delta-5 desaturation of omega6 and omega3 fatty acids in mice. Prostaglandins Leukot Essent Fatty Acids. 58(3):185-191, 1998.

Umeda-Sawada, R., et al. Effects of sesamin and capsaicin on the mRNA expressions of delta-6- desaturases and delta-5-desaturases in rat primary cultured hepatocytes. J Nuti Sci Vitaminol. 49(6):442-446, 2003.

Sesamin is a potent and specific inhibitor of Δ5 desaturase in polyunsaturated fatty acid biosynthesis Sakayu Shimizu

Dietary sesamin and docosahexaenoic and eicosapentaenoic acids synergistically increase the gene expression of enzymes involved in hepatic peroxisomal fatty acid oxidation in rats Metabolism. 2006 Mar;55(3):381-90 Interaction of dietary fat types and sesamin on hepatic fatty acid oxidation in rats Biochem Biophys Acta. 2004 Jun 1;1682(1-3):80-91

Dietary sesame lignans decrease lipid peroxidation in rats fed docosahexaenoic acid

Sesame lignans enhance antioxidant activity of vitamin E in lipid peroxidation systems

Ameliorative influence of sesame lignans on lipid profile and lipid peroxidation in induced diabetic rats

Mode of action of sesame lignans in protecting lowdensity lipoprotein against oxidative damage in vitro

Joo Yeon Kim, Dong Seong Choi and Mun Yhung Jung “Antiphoto-oxidative Activity of Sesamol in Methylene Blue- and Chlorophyll-Sensitized Photo-oxidation of Oil” J. Agric. Food Chem., 51 (11), 3460 -3465, 2003

Ohsawa, Toshiko. “Sesamol and sesaminol as antioxidants.” New Food Industry (1991), 33(6), 1-5

Fukuda, Y., et al. Studies on antioxidative substances in sesame seed. Agricultural Biological Chemistry. 49:301-306, 1985

Lee, S. Y., et al. Effect of sesaminol glucosides on beta-amyloid-induced PC12 cell death through antioxidant mechanisms. Neurosci Res. 52(4):330-341, 2005

Ghafoorunissa, et al. Sesame lignans enhance antioxidant activity of vitamin E in lipid peroxidation systems. Mol Cell Biochem. 262(1-2):195-202, 2004

Yamashita, K., et al. Sesame seed and its lignans produce marked enhancement of vitamin E activity in rats fed a low alpha-tocopherol diet. Lipids. 30(11):1019-1028, 1995


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