In vitro anti-metastatic activity of enterolactone, a mammalian lignan derived from flax lignan, and down-regulation of matrix metalloproteinases in MCF-7 and MDA MB 231 cell lines.

Background: Actin cytoskeleton is involved in actin-based cell adhesion, cell motility, and matrix metalloproteinases(MMPs) MMP2, MMP9, MMP11 and MMP14 are responsible for cell invasion in breast cancer metastasis. The dietary intake of lignan from flax seed gets converted to enterolactone (EL) and enterodiol in the human system. Here we show that the enterolactone has a very significant anti-metastatic activity as demonstrated by its ability to inhibit adhesion and invasion and migration in MCF-7 and MDA MB231 cell lines. Materials and Methods: Migration inhibition assay, actin-based cell motility assay along with reverse transcriptase polymerase chain reaction (RT-PCR) for MMP2, MMP9, MMP11 and MMP14 genes were performed in MCF-7 and MDA MB 231 cell lines. Results: Enterolactone seems to inhibit actin-based cell motility as evidenced by confocal imaging and photo documentation of cell migration assay. The results are supported by the observation that the enterolactone in vitro significantly down-regulates the metastasis-related metalloproteinases MMP2, MMP9 and MMP14 gene expressions. No significant alteration in the MMP11 gene expression was found. Conclusions: Therefore we suggest that the anti-metastatic activity of EL is attributed to its ability to inhibit cell adhesion, cell invasion and cell motility. EL affects normal filopodia and lamellipodia structures, polymerization of actin filaments at their leading edges and thereby inhibits actin-based cell adhesion and cell motility. The process involves multiple force-generating mechanisms of actin filaments i.e. protrusion, traction, deadhesion and tail-retraction. By down-regulating the metastasis-related MMP2, MMP9 and MMP14 gene expressions, EL may be responsible for cell invasion step of metastasis.

Comparative Study of Concentration of Isoflavones and Lignans in Plasma and Prostatic Tissues of Normal Control and Benign Prostatic Hyperplasia

Objective: Isoflavones and lignans are phytoestrogens that have recently gained interest as dietary factors related to prostatic diseases. However, no data on the concentrations in prostate tissue in humans is available. Therefore, the concentrations of isoflavones and lignans in plasma and prostatic tissues according to the prostate volume were compared to determine their possible effect on the benign prostatic growth. Methods: Fasting plasma and prostatic tissue specimens were acquired from 25 men over 50 years of age with similar normal dietary habits and no previous history of drug intake that could affect the isoflavones and lignans levels. The tissue was acquired either during a transurethral resection of the prostate in 15 patients with benign prostatic hyperplasia (BPH) with prostate volume over 40 ml or during a radical cystoprostatectomy in 10 patients with bladder cancer with a prostate volume < 25 ml, who were used as the controls. Quantitative analysis of the isoflavones, specifically equol, daidzein and genistein and lignans, particularly enterodiol and enterolactone, was performed by gas chromatography-mass spectrometry. Results: The mean prostatic concentrations of enterodiol, enterolactone, equol and daidzein in the BPH and the control groups were similar. However, the mean prostatic concentration of genistein was significantly lower in the BPH group than in the control group (65.43 +/- 17.05 vs 86.96 +/- 37.75 ng/ ml, respectively, p=0.032). The plasma concentration of isoflavones and lignans in the two groups were comparable. Conclusion: Isoflavones, but not lignans, have some influence the benign prostatic growth, and the prostatic concentration of genistein possibly has the closest association among them. More studies to further clarify the roles and mechanisms of isoflavone action on BPH including pharmacokinetic studies are recommended.

Fitoestrógenos: una nueva preocupación en la alimentación infantil / Phytoestrogens: a new preoccupation in paediatric nutrition

Los fitoestrógenos son sustancias ambientales naturales, producidas por plantas, que a pesar de su estructura química distinta de los estrógenos, actúan como tales. Estudios en adultos sugieren que tendrían efectos protectores para cánceres hormonodependientes (de próstata y mama), dislipidemias y de la mineralización ósea. Se clasifican en isoflavonas, cumestanos y lignanos, y se encuentran principalmente en legumbres y poroto de soya, brotes de poroto, forraje y granos, y en cereales de grano entero y semillas, respectivamente. Estudios recientes han demostrado que los alimentos infantiles, incluyendo algunas fórmulas lácteas, yogur y alimentos de soya, contienen cantidades considerables de fitoestrógenos. Los efectos de estos sobre la salud infantil no han sido del todo aclarados. Existen evidencias epidemiológicas y clínicas de que al actuar como estrógenos débiles prodrían determinar adelanto de los eventos puberales y telarquia en la niña y ginecomastia en el varón. Se hace una revisión del tema y se plantea la necesidad de realizar estudios destinados a aclarar los efectos de los estrógenos ambientales sobre la salud infantil