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PubMed2005

Anticancer effects of a plant lignan 7-hydroxymatairesinol on a prostate cancer model in vivo.

Clinical intervention studies and experimental studies with lignan-rich diets suggest that lignans may have inhibitory effects on prostate cancer, but no clinical or experimental studies with purified lignans have been published. The purpose of this study was to investigate the effect of a plant lignan 7-hydroxymatairesinol (HMR) on LNCaP human prostate cancer xenografts in athymic mice. Athymic nude male mice were injected subcutaneously with LNCaP cells. Starting 3 days after tumor cell injections, a control diet or a control diet supplemented with 0.15% or 0.30% of HMR was administered to mice and the tumor take rate and growth was observed for 9 weeks. HMR diet inhibited the growth of LNCaP tumors. Mice treated with HMR had smaller tumor volume, lower tumor take rate, increased proportion of nongrowing tumors, and higher tumor cell apoptotic index compared with controls. Furthermore, the cell proliferation index was reduced in mice receiving the 0.30% HMR diet compared with mice receiving the control diet. Our results suggest that dietary HMR started at the early phase of the tumor development inhibits the growth of the LNCaP human prostate cancer xenografts in athymic male mice.

Animals↗

PubMed2003

Lignan precursors from flaxseed or rye bran do not protect against the development of intestinal neoplasia in ApcMin mice.

Phytoestrogens, like isoflavonoids and lignans, have been postulated as possible colorectal cancer protective constituents. To investigate this hypothesis, two high-fiber sources rich in lignan precursors, i.e., rye bran and flaxseed, were tested for their ability to modulate intestinal tumor development in ApcMin mice. Test diets consisted of a control diet (a Western-style diet, adjusted for fiber and/or phytate content) supplemented with 5% flaxseed or 30% rye bran. Chemical analysis of diets and blood samples confirmed the enhanced systemic exposure of mice fed the test diets to the major lignan precursors, i.e., secoisolariciresinol and matairesinol. No statistically significant difference was observed in the incidence and multiplicity of small intestinal and colon tumors at terminal sacrifice between mice fed the control diet or the diet supplemented with 5% flaxseed. With the rye bran diet a statistically significant enhancement of the number of small intestinal tumors in female mice was observed. The number of colon tumors, however, was comparable between the control and rye bran-fed mice of either sex. Furthermore, no activating point mutations in the K-ras oncogene nor positive immunohistochemical staining for the p53 gene were observed in a set of 48 colon tumors. In conclusion, our results demonstrate that increased intake of lignan precursors from flaxseed or rye bran, administered in a Western-style diet, does not protect against intestinal tumor development in an appropriate animal model for intestinal neoplasia such as the ApcMin mice.

Animals↗

PubMed2005

Role of mammalian lignans in the prevention and treatment of prostate cancer.

Prostate cancer is poised to become the most prevalent male cancer in the Western world. In Japan and China, incidence rates are almost 10-fold less those reported in the United States and the European Union. Epidemiological data suggest that environmental factors such as diet can significantly influence the incidence and mortality of prostate cancer. The differences in lifestyle between East and West are one of the major risk factors for developing prostate cancer. Traditional Japanese and Chinese diets are rich in foods containing phytoestrogenic compounds, whereas the Western diet is a poor source of these phytochemicals. The lignan phytoestrogens are the most widely occurring of these compounds. In vitro and in vivo reports in the literature indicate that lignans have the capacity to affect the pathogenesis of prostate cancer. However, their precise mechanism of action in prostate carcinogenesis remains unclear. This article outlines the possible role of lignans in prostate cancer by reviewing the current in vitro and in vivo evidence for their anticancer activities. The intriguing concept that lignans may play a role in the prevention and treatment of prostate cancer over the lifetime of an individual is discussed.

Animals↗

PubMed1997

Inhibitory effects of shouseiryu-to on two-stage carcinogenesis. II. Anti-tumor-promoting activities of lignans from Asiasarum heterotropoides var. mandshuricum.

Two lignans, asarinin (6) and xanthoxylol (7), were isolated from the radix of Asiasarum heterotropoides var. mandshuricum, which consist of a kampo prescription, Shouseiryu-to, as inhibitors of Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). These lignans also exhibited remarkable inhibitory effects on a two-stage carcinogenesis test of mouse skin and pulmonary tumors. Furthermore, it was confirmed that these hydrophobic lignans dissolved in the water decoction of Shouseiryu-to, and these lignans might be among the active constituents of this kampo prescription in terms of its anti-tumor-promoting activity.

Animals↗

PubMed2000

Isoflavonoids and lignans have different potentials to modulate oxidative genetic damage in human colon cells.

Polyphenolic compounds, including isoflavonoids and lignans, have been suggested to be chemopreventive on account of antioxidative properties. In this context it is of importance to have knowledge of their ability to reduce oxidative stress within target cells of tumorigenesis. Therefore, we investigated isoflavonoids and lignans for modulation of oxidative genetic damage in mammalian cells. H(2)O(2)-induced damage as well as endogenous DNA strand breaks and oxidized bases were determined after 30 min incubation of human colon cells with polyphenols using various modifications of the microgel electrophoresis assay (Comet assay). Enterolactone, a mammalian metabolite of plant lignans, was additionally investigated for modulation of intracellular oxidative stress in NIH 3T3 cells using laser scanning microscopy. In vivo effects of rye crispbread (a source of lignans) were investigated in 12 human volunteers by determining genetic damage in lymphocytes and antioxidant activity in plasma (FRAP assay). Genistein induced DNA breaks in the human tumour cell line HT29 clone 19A (12.5-100 microM). The polyphenols (100 microM) did not reduce damage induced by 150 microM H(2)O(2), indicating that they lacked antioxidative potential. At this concentration enterolactone also had no effect on intracellular oxidative stress induced by 31.25 and 125 microM H(2)O(2). In contrast, enterolactone, dihydrogenistein and formononetin reduced endogenous oxidative DNA damage at 100 microM. Daily ingestion of nine slices (76.5 g/day) of rye crispbread per day (containing 41.8 and 33.0 microg/100 g dry weight secoisolariciresinol and matairesinol, respectively) for 2 weeks did not significantly reduce genetic damage in blood lymphocytes, nor was there a modulation of plasma antioxidant capacity. The moderate effects of high concentrations of the tested compounds on endogenous oxidative DNA damage and failure to prevent H(2)O(2)- induced damage are indicative of only marginal protective potential by antioxidant mechanisms. The genotoxic effects of genistein deserve further investigation.

3T3 Cells↗

PubMed2001

[Determination of podophyllotoxin lignans in Dysosma and its allied plants].

The existence of podophyllotoxin lignans in Dysosma versipellis and its allied plants was analyzed by twice developing TLC, and the content by chromotropic-colorimetric assay. The results showed that podophyllotoxin lignans exist in the rhizoma, radix, stem and leaf of Dysosma versipellis and its allied plants. The total lignans content is 2%-7%, and there is a big variation between different species. The total lignans content of Dysosma versipellis is related to the habitat.

Berberidaceae↗

PubMedDate not supplied

The content of lignan glycosides in Forsythia flowers and leaves.

Quantitative determination of lignan glucosides in flowers and leaves of three taxons of Forsythia Vahl was performed using the HPLC method. The main lignan compound in the flowers of F. suspensa appeared to be (+)-pinoresinol beta-D-glucopyranoside, whereas in the leaves of this species phillyrin was the predominant lignan. The content of (+)-pinoresinol beta-D-glucopyranoside in F. suspensa flowers amounted to 4.3-7% and that of phillyrin did not reach 1%. The inverse ratio of (+)-pinoresinol beta-D-glucopyranoside to phillyrin occurred in the leaves of F. suspensa, which contained up to 4.3% of phillyrin and 1.6% and less (+)-pinoresinol beta-D-glucopyranoside. The flowers of F. viridissima and F. x intermedia were rich in arctiin: 5.5-10.2% and up to 11.5%, respectively. The leaves of these two species contained less arctiin: up to 4.3% in F. viridissima and up to 2.3% in F. x intermedia. The flowers showed the highest level of lignans at the phase of buds, it decreased during the blooming time.

Chromatography, High Pressure Liquid↗

PubMed1986

Endogenous lignans--a potential endogenous digitalis.

Lignans are natural products formed by oxidative dimerization of monomeric phenols. A few were recently discovered in human and animal urine, semen and blood plasma but their role has never been assessed. We investigated the actions of mammalian lignans obtained by total synthesis or extracted from the urine of pregnant women, on the Na+K+-pump in human red cells. Some of the tested lignans (enterolactone, prestegane B and 3-O-methylenterolactone) inhibited the Na+K+-pump activity with IC50 ranging from 5 to 9 X 10(-4) mol/l. The IC50 for ouabain (7 X 10(-7) mol/l) was not modified by addition of lignans suggesting a non-competitive inhibition.

4-Butyrolactone↗

PubMed1989

Endogenous digoxin-like activity of mammalian-lignans and their derivatives.

A comparative study was made on the endogenous digoxin-like activity of sixteen mammalian-type lignan derivatives including enterolactone and enterodiol. Cross-reactivity to antidigoxin antibody, inhibition of dog kidney Na+,K+-ATPase, and ouabain displacing activity against [3H]ouabain binding to human erythrocytes on the part of these derivatives were examined and compared in all cases with that of ouabain. meso-2,3-Dibenzylbutane-1,4-diol (meso-HA-1) was found to possess the most potent cross-reactivity to antidigoxin antibody. Several lignans, particularly HA-1 (either meso or dl), dl-2,3-bis(3-methoxybenzyl)butane-1,4-diol(HA-4), dl-2,3-bis(3,4-dimethoxybenzyl)butane-1,4-diol(HA-10), dl-2,3-bis(3,4-dimethoxybenzyl)-1,4-dimethoxybutane(HA-11), and trans-2,3-bis(3,4-dimethoxybenzyl)-gamma-butyrolactone(HA-14) were capable of inhibiting Na+,K+-ATPase activity with IC50 at a concentration less than 5 x 10(-4) M. Meso-HA-1, HA-11 and HA-14 also showed [3H]ouabain displacement activity with IC50 at a concentration of 10(-4)-10(-3) M. These determinations of activity were made at doses 100-1000 times those of ouabain. The synthetic lignans are considered to derive in vivo from plant material usually present in fibrous food. Based on the data obtained, some lignans may possibly be endogenous digitalis-like substances.

Animals↗

PubMedDate not supplied

Interaction of lignans with human sex hormone binding globulin (SHBG).

Lignans bind to sex hormone-binding globulin (SHBG). The lignan with the highest binding affinity is (+/-)-3,4-divanillyltetrahydrofuran. In a double Stobbe condensation--without use of protecting groups--a wide variety of lignans with different substitution pattern in the aromatic and aliphatic part of the molecule was synthesized. These lignans were tested in a SHBG-binding assay which allowed to deduce the following relationship between structure and activity: 1) (+/-)-diastereoisomers are more active than meso compounds 2.) the 4-hydroxy-3-methoxy (guajacyl) substitution pattern in the aromatic part is most effective 3.) the activity increases with the decline in polarity of the aliphatic part of the molecule.

Binding, Competitive↗

PubMedDate not supplied

Mammalian lignans inhibit the growth of estrogen-independent human colon tumor cells.

PURPOSE: The mammalian lignans enterolactone (EL) and enterodiol (ED) derived from precursors in foods, particularly flaxseed, have been shown to reduce the mammary tumor growth due to their antiestrogenic properties. Our objective was to investigate whether lignans have growth inhibitory effects against colon tumor cells and whether these effects are mediated through their antiestrogenic activity. METHODS: Four human colon tumor cell lines (LS174T, Caco-2, HCT-15, T-84) were incubated with various levels of EL, ED or 17 beta-estradiol for 8 to 10 days. Cell proliferation was measured by the BrdU method. RESULTS: At 100 microM concentration, both lignans significantly reduced the proliferation of all cell lines. EL was more than twice as effective as ED at this concentration. The growth was not affected by the presence of 17 beta-estradiol implying that these cells are not estrogen-sensitive. CONCLUSION: Lignans are growth inhibitors of colon tumor cells and they may act through mechanism(s) other than antiestrogenic activity.

4-Butyrolactone↗

PubMed2001

In situ hybridization and immunolocalization of lignan reductases in woody tissues: implications for heartwood formation and other forms of vascular tissue preservation.

Vascular plants have evolved with remarkable ways to form and protect the vasculature apparatus. In certain woody shrubs, the secondary xylem can have within its center a hollowed pith surrounded by secondary xylem, whereas in most trees there is a solid core of heartwood. Both types of woody systems have, however, the commonality of accumulating so-called 'secondary' metabolites, albeit to different extents, whose roles are to protect and preserve the vascular (lignified) tissues. This investigation had as its purpose establishing the nature of the cells involved in the biosynthesis of these specialized 'secondary' metabolites in plants forming heartwood and hollow piths, respectively. This was achieved by determining the tissue-specific expression of two lignan biosynthetic pathway enzymes: pinoresinol-lariciresinol reductase (PLR) and phenylcoumaran benzylic ether reductase (PCBER), soluble enzymes which catalyze analogous benzylic ether reductions of 8-8' and 8-5' linked lignans, respectively. Using Forsythia intermedia, reverse transcription-PCR (RT-PCR) and northern blots revealed that PLR mRNA accumulated mainly in young stems, as well as in young roots and petioles. Furthermore, PLR-specific DIG-labeled riboprobes established that in the stems its mRNA accumulated in the radial parenchyma cells [and to a lesser extent in the developing vessels], as well as in the cambial cells of developing secondary xylem. In addition, immunocytochemical localization of PCBER in Pinus taeda established that it was in the axial and radial parenchyma cells of secondary xylem of stems. That is, irrespective of whether the woody plants formed hollowed piths or heartwood, the 'secondary' metabolite pathways leading to the protective lignans predominantly involved axial and radial parenchyma cells. This is in contrast to monolignol coupling (i.e. the entry point to both the lignans and lignins), which appears to be more restricted to the vascular cambial regions.

Asteraceae↗

PubMed1993

[Study on lignans from Diphylleia sinensis].

A new lignan along with eight known lignans and a flavonoid were isolated from the rhizomes of Diphylleia sinensis Li.. Their structures were elucidated on the basis of chemical and spectral analysis. The new lignan, compound IX, was named as picropodophyllin-1-ethyl ether (IX). The eight known lignans were identified as podophyllotoxin (I), isopicropodophyllone (II), dehydropodophyllotoxin (III), diphyllin (IV), picropodophyllin (V), podophyllotoxone (VI), 4'-demethylpodophyllotoxin (VII) and picropodophyllin glucoside (VIII). Compounds II, VI, VII and VIII were found for the first time from the rhizome of this plant. The flavonoid was identified as kaempferol.

Antineoplastic Agents, Phytogenic↗

PubMed2002

Determination of lignans in Schisandra chinensis using micellar electrokinetic capillary chromatography.

Micellar electrokinetic capillary chromatography (MEKC) has been developed as a promising method for the determination of lignans in plant samples. The separation conditions have been optimized with respect to the different parameters including sodium dodecyl sulfate (SDS) and acetonitrile concentration, pH of the background electrolyte, separation voltage, and capillary temperature. The background electrolyte consisting of 40 mM SDS and 35% acetonitrile in 10 mM tetraborate buffer (pH 9.3) was found to be the most suitable electrolyte for this analysis. The applied voltage of 28 kV (positive polarity) and the capillary temperature 25 degrees C gave the best separation of lignans. The interday reproducibility of the peak areas and the migration times was below 2.0%. The results of MEKC analyses were compared with those obtained by capillary electrochromatography (CEC) and reversed-phase high-performance liquid chromatography (RP-HPLC). The possibilities of using this method for the determination of lignans in drug and in serum samples were also tested.

Chromatography, Micellar Electrokinetic Capillary↗

PubMed2006

Mammalian lignans enterolactone and enterodiol, alone and in combination with the isoflavone genistein, do not promote the growth of MCF-7 xenografts in ovariectomized athymic nude mice.

This study determined the effect of the mammalian lignans enterolactone (ENL) and enterodiol (END) alone and in combination with the isoflavone genistein (GEN) on the growth of MCF-7 tumors in ovariectomized nude mice. Ovariectomized athymic nude mice with established MCF-7 tumors were fed a basal diet (AIN-93G) and divided into 5 groups that received daily subcutaneous injections (10 mg/kg body weight (BW)) of ENL, END, GEN, a mixture of these compounds (MIX), or vehicle as a negative control for 22 weeks. A positive control group was implanted with an estradiol pellet in order to establish an estrogenic tumor growth response. In the ENL- and END-treated mice, palpable tumors regressed significantly by 91 and 83%, respectively, resulting in final tumors that were similar to the negative control tumors. However, tumor cell apoptosis was significantly enhanced by the lignans. In the GEN-treated mice, tumors initially regressed significantly by 64% but regression ceased following prolonged treatment, resulting in final tumors that were significantly larger compared to negative control, ENL-, and END-treated mice, in part by increasing tumor cell proliferation. The MIX treatment significantly regressed palpable tumors by 87% similar to negative control group, with no effects on tumor cell apoptosis or proliferation. The isoflavone GEN alone promoted the growth of established MCF-7 human breast cancer xenografts after prolonged treatment while the mammalian lignans ENL and END did not. When these phytoestrogens were given in combination, no tumor growth-promoting effects were observed. (c) 2005 Wiley-Liss, Inc.

4-Butyrolactone↗

PubMed2004

Dibenzocyclooctadiene lignans from Schisandra chinensis protect primary cultures of rat cortical cells from glutamate-induced toxicity.

A methanolic extract of dried Schisandra fruit (Schisandra chinensis Baill.; Schisandraceae) significantly attenuated the neurotoxicity induced by L-glutamate in primary cultures of rat cortical cells. Five dibenzocyclooctadiene lignans (deoxyschisandrin, gomisin N, gomisin A, schisandrin, and wuweizisu C) were isolated from the methanolic extract; their protective effects against glutamate-induced neurotoxicity were then evaluated. Among the five lignans, deoxyschisandrin, gomisin N, and wuweizisu C significantly attenuated glutamate-induced neurotoxicity as measured by 1). an inhibition in the increase of intracellular [Ca(2+)]; 2). an improvement in the glutathione defense system, the level of glutathione, and the activity of glutathione peroxidase; and 3). an inhibition in the formation of cellular peroxide. These results suggest that dibenzocyclooctadiene lignans from Schisandra chinensis may possess therapeutic potential against oxidative neuronal damage induced by excitotoxin.

Animals↗

PubMed2006

Complete assignments of 1H and 13C NMR data for seven arylnaphthalide lignans from Justicia procumbens.

Three new arylnaphthalide lignans named 6'-hydroxy justicidin A (1), 6'-hydroxy justicidin B (2) and 6'-hydroxy justicidin C (3) have been isolated from the whole plant of Justicia procumbens, together with four known ones, neojusticin A (4), chinensinaphthol methyl ester (5), isodiphyllin (6) and taiwanin C (7). The complete assignments of 1H and 13C NMR chemical shifts for the new lignans and the 13C NMR chemical shifts for the known lignans were obtained for the first time by means of 2D NMR techniques, including HSQC and HMBC.

Acanthaceae↗

PubMed2006

A new furofuran lignan from Geranium thunbergii Sieb. et Zucc.

A new furofuran lignan, 4-hydroxykobusin (3), together with known lignans, kobusin (1), and 7,7'-dihydroxybursherenin (2), were isolated from the whole plant of Geranium thunbergii Sieb. et Zucc (Geraniaceae). The structures were determined based on the spectral data and a comparison with the published data. This is the first report of the presence of furofuran lignan in Geranium species.

Cell Line↗