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PubMed1995

Urinary isoflavonoid phytoestrogen and lignan excretion after consumption of fermented and unfermented soy products.

OBJECTIVE: To compare the effects of consumption of fermented and unfermented soy products on excretion of urinary isoflavonoid phytoestrogens and lignans in healthy men. DESIGN: A randomized, crossover trial consisting of two 9-day feeding periods following 5 days of baseline data collection. SUBJECTS: Healthy men, aged 20 to 40 years, were recruited from the University of Minnesota Twin Cities community. Of the 22 subjects who began the study, 17 completed all feeding periods. INTERVENTIONS: Fermented soy product (112 g tempeh) or unfermented soy (125 g soybean pieces) was consumed during each controlled feeding period. MAIN OUTCOME MEASURE: Urine samples collected while subjects consumed their habitual diets and on the last 3 days of each feeding period were analyzed for isoflavonoid and lignan content by isotope dilution gas chromatography-mass spectrometry. STATISTICAL ANALYSIS PERFORMED: Comparisons of isoflavonoid and lignan excretion were analyzed using the general linear model procedure. Orthogonal contrasts were used to determine treatment differences of interest. RESULTS: Urinary excretion of isoflavonoids (equol, O-desmethylangolensin [O-DMA], daidzein, genistein) was higher and excretion of lignans (enterodiol, enterolactone) was lower when subjects consumed soy-supplemented diets than when they consumed their habitual diets (P < .05). Urinary isoflavonoid excretion and lignan excretion were similar when subjects consumed tempeh and soybean pieces diets; however, recovery of daidzein and genistein was significantly higher when subjects consumed the tempeh diet than when they consumed the soybean pieces diet (P < .002). When fed soy, 5 of 17 subjects excreted high amounts of equol. These five subjects tended to excrete less O-DMA and daidzein than the 12 subjects who excreted low amounts of equol (P < .06). CONCLUSIONS: Fermentation of soy decreased the isoflavone content of the product fed but increased the urinary isoflavonoid recovery. This finding suggests that fermentation increases availability of isoflavones in soy.

4-Butyrolactone↗

PubMed1995

Vegetables, fruits, and legumes: effect on urinary isoflavonoid phytoestrogen and lignan excretion.

OBJECTIVE: To compare the effect of vegetable, fruit, and legume consumption on urinary isoflavonoid phytoestrogen and lignan excretion. DESIGN: After 4 days of data collection, during which subjects consumed their habitual diets, subjects were randomly placed on four 9-day controlled experimental diets with each subject receiving each diet in a random order. SUBJECTS: Seven men and three women, aged 20 to 35 years, were recruited from the University of Minnesota Twin Cities community. INTERVENTIONS: All subjects consumed four experimental diets in an assigned random order: a controlled basal diet, a legume/allium diet (containing garbanzo beans, garlic, and onions), and diets low or high in vegetables and fruits (containing apples, pears, potatoes, and carrots). MAIN OUTCOME MEASURES: Urine samples that were collected while subjects consumed their habitual diets and during the last 3 days of each feeding period were analyzed for isoflavonoid and lignan content using isotope dilution gas chromatography-mass spectrometry. STATISTICAL ANALYSIS PERFORMED: The effect of vegetable and fruit intake on urinary isoflavonoid and lignan excretion was analyzed using the general linear model procedure. Post hoc comparisons were made using Duncan's multiple range test. RESULTS: Subjects excreted more of the lignan enterodiol on the high vegetable/fruit diet compared with the basal and legume/allium diets (P = .03); more of the isoflavonoids O-desmethylangolensin (O-DMA), genistein, and sum of isoflavonoids on the legume/allium diet compared with the other controlled diets (P < .05); and more of the isoflavan equol on the basal and legume/allium diets compared with the high vegetable/fruit diet (P < .01). Subjects who excreted higher levels of equol on the basal and legume/allium diets also consumed more of the milk-based pudding provided as part of the controlled diets. CONCLUSIONS: Urinary lignan and isoflavonoid excretion changed in response to alterations in vegetable, fruit, and legume intake under controlled dietary conditions.

Adult↗

PubMed1999

Regiochemical control of monolignol radical coupling: a new paradigm for lignin and lignan biosynthesis.

BACKGROUND: Although the lignins and lignans, both monolignol-derived coupling products, account for nearly 30% of the organic carbon circulating in the biosphere, the biosynthetic mechanism of their formation has been poorly understood. The prevailing view has been that lignins and lignans are produced by random free-radical polymerization and coupling, respectively. This view is challenged, mechanistically, by the recent discovery of dirigent proteins that precisely determine both the regiochemical and stereoselective outcome of monolignol radical coupling. RESULTS: To understand further the regulation and control of monolignol coupling, leading to both lignan and lignin formation, we sought to clone the first genes encoding dirigent proteins from several species. The encoding genes, described here, have no sequence homology with any other protein of known function. When expressed in a heterologous system, the recombinant protein was able to confer strict regiochemical and stereochemical control on monolignol free-radical coupling. The expression in plants of dirigent proteins and proposed dirigent protein arrays in developing xylem and in other lignified tissues indicates roles for these proteins in both lignan formation and lignification. CONCLUSIONS: The first understanding of regiochemical and stereochemical control of monolignol coupling in lignan biosynthesis has been established via the participation of a new class of dirigent proteins. Immunological studies have also implicated the involvement of potential corresponding arrays of dirigent protein sites in controlling lignin biopolymer assembly.

Amino Acid Sequence↗

PubMed1998

Studies on the genotoxicity of the mammalian lignans enterolactone and enterodiol and their metabolic precursors at various endpoints in vitro.

The mammalian lignans enterolactone (ENL) and enterodiol (END) are formed by intestinal bacteria from the plant lignans matairesinol (MAT) and secoisolariciersinol (SEC), respectively, which are ingested with different types of food. ENL and END are weak estrogens. According to epidemiological and biochemical studies, lignans may act as anticarcinogens, but little is known about their genotoxic potential. We have therefore investigated the effects of ENL, END, MAT and SEC on cell-free microtubule assembly and at the following genetic endpoints in cultured male Chinese hamster V79 cells: disruption of the cytoplasmic microtubule complex, induction of mitotic arrest, induction of micronuclei and their characterization by CREST staining, and mutagenicity at the HPRT gene locus. The lignans were tested at concentrations of 200 microM in the cell-free system and 100 microM in cultured cells, which represents the limit of solubility in each assay. The established aneuploidogen diethylstilbestrol and the clastogen 4-nitroquinoline-N-oxide were used as positive reference compounds. As none of the four lignans had any activity at the endpoints studied, we conclude that ENL, END, MAT and SEC are devoid of aneuploidogenic and clastogenic potential under the experimental conditions used in this study.

4-Butyrolactone↗

PubMed2003

Liquid chromatographic-tandem mass spectrometric method for the plant lignan 7-hydroxymatairesinol and its potential metabolites in human plasma.

A HPLC-MS-MS method was developed for the determination of the plant lignan 7-hydroxymatairesinol and its potential metabolites matairesinol, oxomatairesinol, alpha-conidendrin, 7-hydroxyenterolactone, enterodiol, and enterolactone in human plasma. The method included sample cleanup by solid-phase extraction (SPE) and analysis using a PE Sciex API3000 triple quadrupole mass spectrometer with electrospray ionisation. The lignans were quantified using two deuterated internal standards. They showed good chromatographic linearity, analysis repeatability, and SPE recovery in the presence of plasma. In pooled plasma and in plasma samples collected from two individual subjects lignan glucuronides and sulfates were enzymatically hydrolysed to free lignans and then analysed. All the lignans could be detected in the samples.

Chromatography, High Pressure Liquid↗

PubMed2005

Antioxidative catechol lignans converted from sesamin and sesaminol triglucoside by culturing with Aspergillus.

Sesamin and sesaminol triglucoside in sesame seeds are major lignans that display an abundance of biological activities. Although their antioxidative activity in vitro is weak, they have been reported to suppress oxidative stress in vivo. We investigated the production of new antioxidative lignans from sesame lignans by culturing with the genus Aspergillus to enhance the function of food materials. Media containing sesamin or sesaminol triglucoside increased antioxidative activity for DPPH radical scavenging by culturing with Aspergillus usamii mut. shirousamii RIB2503. The antioxidative lignans in sesamin medium were identified as sesamin 2,6-dicatechol and episesamin 2,6-dicatechol. Those in sesaminol triglucoside medium were identified as sesaminol 6-catechol and episesaminol 6-catechol, which are novel antioxidative lignans. It is suggested that they may exhibit higher antioxidative activity than sesamin and sesaminol triglucoside because they have the catechol functional moiety.

Antioxidants↗

PubMed2005

Quantification of lignans in food using isotope dilution gas chromatography/mass spectrometry.

The optimization and validation of a protocol for the quantification of six dietary lignans, i.e., secoisolariciresinol, matairesinol, lariciresinol, pinoresinol, medioresinol, and syringaresinol, in food are presented. The method incorporates isotope dilution to ensure correct accuracy and precision, introducing the utilization of individual stable 13C3-labeled lignans. To demonstrate the potential of this new method, preliminary results of the levels of dietary lignans in selected foods are presented. It is concluded that the method fulfils the reliability criteria and can be applied to the analysis of the most common lignans in human food, being an essential asset to establish the intake of lignans in a determined population and their relation with disease prevention.

Carbon Isotopes↗

PubMed2005

An update on bioactive plant lignans.

Lignans are a class of secondary plant metabolites produced by oxidative dimerization of two phenylpropanoid units. Although their molecular backbone consists only of two phenylpropane (C6-C3) units, lignans show an enormous structural diversity. There is a growing interest in lignans and their synthetic derivatives due to applications in cancer chemotherapy and various other pharmacological effects. This review deals with lignans possessing anticancer, antioxidant, antimicrobial, anti-inflammatory and immunosuppressive activities, and comprises the data reported in more than 100 peer-reviewed articles, so as to highlight the recently reported bioactive lignans that could be a first step towards the development of potential new therapeutic agents.

Anti-Bacterial Agents↗

PubMed2001

A fast and simple GC MS method for lignan profiling in Anthriscus sylvestris and biosynthetically related Plant species.

A new GC-MS method for monitoring lignans was developed to study the variation in plants and elucidate the biosynthetic steps. A simple and fast extraction procedure for lyophilised plant material was developed, giving a lignan-rich extract. A GC-MS method was set up using an apolar WCOT fused silica column using a high temperature programme (150 degrees C to 320 degrees C at 15 degrees C min(-1)). This new GC-MS method gave a clear lignan profile of plant material. It was possible to show the large variation in the concentrations of deoxypodophyllotoxin (DOP), yatein and anhydropodorhizol (AHP) in Anthriscus sylvestris (L.) Hoffm. plants growing on different locations using cinchonidin as an internal standard. In contrast with existing GC methods for lignan analysis no derivatisation is needed. It is also possible to use this method for the detection of different classes of lignans in biosynthetically related plant species.

4-Butyrolactone↗

PubMed2003

Lignan profiles of indoor-cultivated Anthriscus sylvestris.

In a previous study we have shown that different populations of Anthriscus sylvestris (L.) Hoffm. (Apiaceae) yield significantly different lignan profiles. In this study we collected the seeds of A. sylvestris from 4 locations, one in England and three in The Netherlands. The seeds germinated and were grown under identical laboratory conditions. After 5 months the plants were harvested and the lignan profile in the roots and aerial parts was analysed using GC-MS. The plants from the seeds of the 4 locations showed several significant phenotypic differences in, for instance, dry-weight. However the 4 groups did not differ significantly in their lignan profile in their roots. The lignans in the roots of A. sylvestris, deoxypodophyllotoxin, yatein and anhydropodorhizol reached, on average, equal amounts in all 4 groups. Within the 4 groups, however, a large quantitative variation in lignan profile between the individual plants was observed, pointing to within-population genetic differences between individual plants.

Apiaceae↗

PubMed2005

Anti-inflammatory properties of extracts, fractions and lignans isolated from Phyllanthus amarus.

This study assessed the anti-inflammatory effect of the extracts and purified lignans obtained from Phyllanthus amarus. Given orally, the hexane extract (HE), the lignan-rich fraction (LRF), or the lignans phyltetralin, nirtetralin, niranthin, but not hypophyllanthin or phyllanthin, inhibited carrageenan (Cg)-induced paw oedema and neutrophil influx. The HE, the LRF or nirtetralin also inhibited the increase of IL1-beta tissue levels induced by Cg. Furthermore, bradykinin (BK)-, platelet activating factor (PAF)- and endothelin-1 (ET-1)-induced paw oedema were significantly inhibited by the HE or LRF while histamine- and substance P-induced paw oedema were unaffected. Finally, nirtetralin or phyltetralin caused inhibition of paw oedema induced by PAF or ET-1. These results show that the HE, the LRF and the lignans niranthin, phyltetralin and nirtetralin exhibited marked anti-inflammatory properties and suggest that these lignans seem to be the main active principles responsible for the anti-inflammatory properties reported for the HE of P. amarus.

Administration, Oral↗

PubMed1992

Anti-oxidant activity of dibenzocyclooctene lignans isolated from Schisandraceae.

The anti-oxidant activity of nine dibenzocyclooctene lignans isolated from Schisandra chinensis, S. rubriflora, and Kadsura longipedunculata, respectively, was studied. Seven of the 9 lignans (1 mM) inhibited iron/cysteine-induced lipid peroxidation (malondialdehyde, MDA, formation) of rat liver microsomes as well as superoxide anion production in the xanthine/xanthine oxidase system. The actions of the 7 lignans were much more potent than vitamin E at the same concentration of 1 mM. Among the lignans, schisanhenol was the most active one. This compound also prevented the decrease of membrane fluidity of liver microsomes induced by iron/cysteine. The results indicated that seven of the lignans such as schisanhenol have anti-oxidant activities.

Animals↗

PubMed1998

Lignan and isoflavonoid concentrations in tea and coffee.

Tea is a beverage consumed widely throughout the world. The existence in tea of chemopreventing compounds possessing antimutagenic, anticarcinogenic and antioxidative properties has been reported. High intakes of tea and foods containing flavonoids have recently been shown to be negatively correlated to the occurrence of CHD. However, tea may contain other compounds with similar activities. Using a new gas chromatographic-mass spectrometric method we measured lignans and isoflavonoids in samples of twenty commercial teas (black, green and red varieties) and, for comparison, six coffees. Both unbrewed and brewed tea were investigated. The analysis of the teas yielded relatively high levels of the lignans secoisolariciresinol (5.6-28.9 mg/kg; 15.9-81.9 mumol/kg) and matairesinol (0.56-4.13 mg/kg; 1.6-11.5 mumol/kg) but only low levels of isoflavonoids. Because the plant lignans, as well as their mammalian metabolites enterolactone and enterodiol, have antioxidative properties and these mammalian lignans occur in high concentrations in plasma, we hypothesize that lignan polyphenols may contribute to the protective effect of tea on CHD.

Butylene Glycols↗

PubMed2006

Short-term effects of a combination of isoflavones, lignans and Cimicifuga racemosa on climacteric-related symptoms in postmenopausal women: a double-blind, randomized, placebo-controlled trial.

The present study aimed to evaluate the short-term effects of a combination of isoflavones, lignans and Cimicifuga racemosa on acute climacteric-related symptoms in postmenopausal women in a double-blind, randomized, placebo-controlled trial performed at the menopause clinic of our department. Eighty healthy postmenopausal women were randomly assigned to two treatment groups - one receiving the combination (group A, n = 40), the other receiving calcium supplements (group B, n = 40) - for three cycles of 28 days. Climacteric-related symptoms were evaluated by the Kupperman index (KI) at baseline and after the three cycles of treatment. At baseline no significant difference was detected in KI between groups A and B; however, after three cycles of treatment, KI was significantly (p < 0.05) lower in group A compared with baseline and with group B. We conclude that the administration of a combination of isoflavones, lignans and C. racemosa already reduces acute climacteric symptoms in postmenopausal women after 3 months of treatment. This prompt effect is probably due to the different pharmacokinetic properties of isoflavones and lignans; isoflavones are absorbed faster than lignans, while lignans are removed later. The combination of these molecules can guarantee a better reduction of postmenopausal symptoms over a 24-h period.

Cimicifuga↗

PubMed1994

Urinary lignan and isoflavonoid excretion in premenopausal women consuming flaxseed powder.

Lignans and isoflavonoid phytoestrogens, produced from plant precursors by colonic bacteria, may protect against certain cancers. We examined the effects of flaxseed consumption on urinary lignans and isoflavonoids. Eighteen women consumed their usual omnivorous diets for three menstrual cycles and their usual diets supplemented with flaxseed powder (10 g/d) for three cycles in a randomized crossover design. Three-day urine samples from follicular and luteal phases were analyzed for lignans and isoflavonoids by isotope-dilution gas chromatography--mass spectrometry. Excretion of the lignans enterodiol and enterolactone increased with flaxseed from 1.09 +/- 1.08 and 3.16 +/- 1.47 to 19.48 +/- 1.10 and 27.79 +/- 1.50 mumol/d, respectively (P < 0.0002). Enterodiol and enterolactone excretion varied among subjects in response to flaxseed (3- to 285-fold increase). There were no differences in excretion of isoflavonoids (daidzein, genistein, equol, and O-desmethylangolensin) or the lignan matairesinol with flaxseed. Excretion was not altered by phase of menstrual cycle or duration of flaxseed consumption.

Administration, Oral↗

PubMed1996

Flaxseed and its lignan and oil components reduce mammary tumor growth at a late stage of carcinogenesis.

Flaxseed, a rich source of mammalian lignan precursor secoisolariciresinol-diglycoside (S.D.) and alpha-linolenic acid (ALA), has been shown to be protective at the early promotion stage of carcinogenesis. The objective of this study was to determine whether supplementation with flaxseed, its lignan or oil fractions, beginning 13 weeks after carcinogen administration, would reduce the size of established mammary tumors (present at the start of treatment) and appearance of new tumors in rats. Dietary groups consisted of the basal diet (BD, 20% corn oil) alone or supplemented with a gavage of 2200 nmol/day S.D. [S.D., equal to level in 5% flaxseed (F)], 1.82% flaxseed oil (OIL, equal to level in 5% F) or 2.5% or 5% flaxseed (2.5% F and 5% F, respectively). After 7 weeks of treatment, established tumor volume was over 50% smaller in all treatment groups (OIL, 2.5% F, 5% F, P < 0.04; S.D., P < 0.08) while there was no change in the BD group. New tumor number and volume were lowest in the S.D. (P < 0.02) and 2.5% F (P < 0.07) groups. The combined established and new tumor volumes were smaller for the S.D., 2.5% F and 5% F groups (P < 0.02) compared to the OIL and BD groups. The high negative correlation (r = -0.997, P < 0.001) between established tumor volume and urinary mammalian lignan excretion in the BD, S.D., 2.5% F and 5% F groups indicates that the reduction in tumor size is due in part to the lignans derived from the S.D. in flaxseed. However, there was no relationship between new or total tumor development and urinary lignan levels. The effect of flaxseed oil may be related to its high ALA content. In conclusion, the S.D. in flaxseed appears to be beneficial throughout the promotional phase of carcinogenesis whereas the oil component is more effective at the stage when tumors have already been established.

Animals↗

PubMed2005

The usual intake of lignans but not that of isoflavones may be related to cardiovascular risk factors in U.S. men.

Isoflavone supplementation in the form of soy protein-containing isoflavones is associated with beneficial lipid changes. Information on usual isoflavone and lignan intakes in the diet of Western men and their associations with cardiovascular risk factors is not available. From the Health Professionals Follow-up Study, we selected 468 men, aged 47-83 y, who were free of cardiovascular disease, diabetes, and cancer, and who had provided a blood sample in 1994. We measured circulating total, LDL, and HDL cholesterol, triacylglycerol, lipoprotein(a), apolipoprotein (apo) A1, apoB, hemoglobin (Hb)A1c, insulin, C-peptide, and leptin concentrations. Isoflavone and lignan intakes were calculated from a FFQ. We used multivariate linear regression. None of the cardiovascular risk factors was strongly associated with isoflavone intake. Blood levels of LDL cholesterol and apoB tended to increase with increasing lignan intake [for LDL cholesterol, quartile 4 -quartile 1 = 9% (95% CI 1%; 16%), P for trend = 0.01, and for apo B, quartile 4 -quartile 1 = 9% (95% CI 1%; 16%), P for trend = 0.02]. Fasting insulin and C-peptide tended to decrease with increasing lignan intake [for insulin, quartile 4 -quartile 1 = -11% (95% CI -55%; -8%), P for trend = 0.02, and for C-peptide, quartile 4 -quartile 1 = -25% (95% CI -44; -6%), P for trend = 0.01]. Our results suggest that intake of isoflavones within the range of Western diets is not associated with a cardiovascular risk profile among men. Diets high in lignan intake may increase apoB-containing lipoproteins and decrease fasting insulin secretion, but these findings require confirmation.

Aged↗

PubMed2000

Exposure to flaxseed or purified lignan during lactation influences rat mammary gland structures.

Previous investigation demonstrated that feeding a 10% flaxseed (10F) diet during pregnancy and lactation enhanced the differentiation of highly proliferative terminal end bud (TEB) structures of rat mammary gland into less proliferative alveolar buds and lobules. From this study, it was hypothesized that the lignan component in flaxseed mediated the observed effects. Because mammary glands with more TEBs are more susceptible to carcinogens, exposure to flaxseed during early postnatal life may reduce the risk of developing mammary cancer. Our objectives were to elucidate whether exposure to flaxseed during lactation only and during pregnancy and lactation can similarly influence the differentiation of mammary gland structures and also to identify whether the lignan component of flaxseed is the biologically active agent. Offspring were exposed to a 10F diet or a dose of purified lignan equivalent to that in a 10F diet (10S) during lactation only or from lactation to postnatal Day 50. Compared with controls, exposure to 10F or 10S during lactation only or from lactation to postnatal Day 50 reduced the number of TEBs and resulted in a rise in the number of alveolar buds. In conclusion, exposure to flaxseed or its purified lignan during lactation is a critical period in which mammary gland development may be promoted by enhancing the differentiation of the mammary gland structures. However, continuous exposure, particularly to purified lignans, resulted in the most differentiation of the mammary gland. The next step is to determine whether the changes in mammary gland structures are chemopreventive in rats challenged with a carcinogen.

Analysis of Variance↗