Mammalian lignans

ADLERCREUTZ H, BANNWART C, WAHALA K, MAKELA T, BRUNOW G, BASE T, AROSEMENA P J, KELLIS J T J R, VICKERY L E (1993) Inhibition of human aromatase by mammalian lignans and isoflavonoid phytoestrogens. J Steroid Biochem Mol Biol. 44 147-53. 

Nicolle C, Manach C, Morand C, Mazur W, Adlercreutz H, Remesy C and Scalbert A (2002), Mammalian lignan formation in rats fed a wheat bran diet , J Agric Food Chem, 50, 6222-6226. 

The plant precursors of mammalian lignans include secoisolaricinol, laricresinol, matair-esinol, 7-hydroxymatairesinol, pinoresinol, and lignin. ° ° Flaxseed and whole cereal grains are considered the most important dietary sources, but many others are known, for example, strawberry achenes, berries, coffee beans, tea leaves, etc. ... 

Gut microflora metabolites may also be important. As discussed above, the mammalian lignan aglycones, enterodiol and enterolactone, are estrogenic, and equol is more estrogenic than its dietary precursor, the isoflavone daidzein. ... 

Wang, L.Q., Meselhy, M.R., Li, Y., Qin, G.W., and Hattori, M., Human intestinal bacteria capable of transforming secoisolariciresinol diglucoside to mammalian lignans, enterodiol and enterolactone, Chem. Pharm. Bull, 48, 1606, 2000. 

Jacobs, E., Kulling, S.E., and Metzler, M., Novel metabolites of the mammalian lignans enterolactone and enterodiol in human urine, J. Steroid Biochem. Mol Biol, 68, 211, 1999. 

Heinonen, S., Nurmi, T., Liukkonen, K., Poutanen, K., Wahala, K., Deyama, T., Nishibe, S., and Adlercreutz, H., In vitro metabolism of plant lignans new precursors of mammalian lignans enterolactone and enterodiol, J. Agric. Food Chem., 49, 3178, 2001. 

A dose-dependent formation of mammalian lignans has been reported (Nesbitt et al., 1999 Rickard et al., 1996). In humans, a dose-dependent response was based on daily dietary intake of flaxseed between 5 and 25 grams as flaxseed or in the form of a baked product (Nesbitt et al., 1999). Higher flaxseed intakes may not produce additional mammalian lignan concentrations based on the observation in rats that showed 4.4 pmol SDG/d did not produce higher mammalian lignan concentrations than the 2.2 pmol SDG/d treatment (Rickard et al., 1996). 

The presence of the oxidized metabolites is unique and may provide additional reasons for the health benefits of lignans. Classical antioxidant mechanisms show that the addition of an ortho hydroxyl group to a monophenol enhances the antioxidant activity of the original monophenol. Thus, some of the mammalian lignan metabolites may actually have greater or different activity than the parent lignan. Kitts et al (1999) reported that enterolactone and enterodiol had greater antioxidant activity than the parent... 

FIG. 3 Oxidized mammalian lignans observed by Jacobs et al (1999) and Niemeyer et al (2000) in rat and human urine. 

Brooks, J.D. and Thompson, L.U. 2005. Mammalian lignans and genistein decrease the activities of aromatase and 17p-hydroxysteroid dehydrogenase in MCF-7 cells. J. Steroid Biochem. Mol. Biol. 94, 461—467. 

Kitts, D.D., Yuan, Y.V., Wijewickreme, A.N., and Thompson, L.U. 1999. Antioxidant activity of the flaxseed lignan secoisolariciresinol diglycoside and its mammalian lignan metabolites enterodiol... 

Lin, X., Switzer, B.R., and Demark-Wahnefried, W. 2001. Effect of mammalian lignans on the growth of prostate cancer cell lines. Anticancer Res. 21, 3995-4000. 

Orcheson, L.J., Rickard, S.E., Seidl, M.M., and Thompson, L.U. 1998. Flaxseed and its mammalian lignan precursor cause a lengthening or cessation of estrous cycling in rats. Cancer Lett. 125,69-76. 

Thompson, L.U., Robb, P., Serraino, M., and Cheung, F. 1991. Mammalian lignan production from various foods. Nutr. Cancer 16, 43-52. 

Thompson, L.U., Seidl, M., Rickard, S., Orcheson, L., and Fong, H. 1996b. Antitumorigenic effect of a mammalian lignan precursor from flaxseed. Nutr. Cancer 26, 159-165. 

Begum, A.N., Nicolle, C., Mila, I., Lapierre, C., Nagano, K., Fukushima, K., Heinonen, S.-M., Adlercreutz, H., Remesy, C. and Scalbert, A. (2004) Dietary lignins are precursors of mammalian lignans in rats. Journal of Nutrition 134,120-127. 

Enterodiol] (lignan) Mammalian lignan derived from intestinal bacterial modification of lignans from ingested Secale cereale (rye) (Poaceae) AROM... 

Figure 3. Mammalian lignan formation in digestive tract and their plant precursors (19).

Lignans that are present in the serum, urine, bile and seminal fluid of humans, chimpanzees and vervet monkeys are called mammalian lignans. Mammalian lignans inhibit cell membrane Na+/K+-ATPase, the enzyme that maintains the Na+/K+ balance... 

Trachelogenin (39) showed the most potent activity, IC50 1.1 x 10 M while arylnaphthalenes showed no significant activity [80]. Several mammalian lignans containing a butyrolactone group—enterolactone (118), 3-0-methylenterolactone... 

---