Soy isoflavones and cellular mechanics

Abstract

Soy isoflavones are diphenolic compounds that are frequently used for alternative treatment of ageing symptoms in both genders. They operate at principally two hierarchical levels of functional organization - cellular and molecular, while these 'types' of action appear to have indefinite borders. Soy isoflavone action at the cellular level involves inter alia the effects on cell mechanics. This epigenetic and modular determinant of cell function and fate is defined by: the anchorage to extracellular matrix (ECM) and neighboring cells, cytoskeleton organization, membrane tension and vesicle trafficking. Soy isoflavones have been reported to: (i) generally fashion an inert cell phenotype in some cancers and enhance the cell anchorage in connective tissues, via the effects on ECM proteins, focal adhesion kinases-mediated events and matrix metalloproteinases inhibition; (ii) affect cytoskeleton integrity, the effects being related to Ca(2+) ions fluxes and involving cell retraction or differentiation/proliferation-related variations in mechanical status; (iii) increase, remain "silent" or decrease membrane tension/fluidity, which depends on polarity and a number and arrangement of functional groups in applied isoflavone; (iv) provoke inhibitory effects on vesicle trafficking and exo-/endocytosis, which are usually followed by changed cell morphology. Here we present and discuss the abundance of effects arising from cells' "encounter" with soy isoflavones, focusing on different morphofunctional definers of cell mechanics.

Effects of soy phytoestrogens on pituitary-ovarian function in middle-aged female rats

“…In fact, gonadotropic and lactotropic pituitary cells were changed in shape, with unevenly stained cytoplasms which gave cells the appearance of vacuolization. Considering the presence of various forms of ERs (with the serious potential of phytoestrogen sensitivity) in the pituitary gonadotropic and lactotropic cells, not only in the nucleus and cytoplasm but also in the membrane of rough endoplasmic reticulum and secretory vesicles [41], and keeping in mind that vesicular trafficking crucially defines cell mechanical status [12,42], we can assume that the observed changes in cell morphology may be mediated by both genomic and non-genomic pathways.…”

“…Interestingly, their polyphenolic structure may enable their binding to either nuclear or membrane forms of ERs, which increases the range of their estrogen-like activities to cover both the slow, genomic, and the fast, signaling-related ones [11]. Phytoestrogens may also manipulate the endogenous hormone levels by interfering with sex hormone-binding globulin (SHBG) as well as with the enzymes involved in steroid biosynthesis [12]. Finally, they may affect the numerous oxidative stress pathways/molecules which imply significant anti-aging benefits [13].…”

In vitro effects of prolonged exposure to quercetin and epigallocatechin gallate of the peripheral blood mononuclear cell membrane

“…It was proven that at lower alcohol concentrations (methanol, ethanol, propanol and butanol), fluidity gradually increased and the effect was reversed at higher concentrations. Many studies were devoted to the effect of flavonoids on the cell membrane, using different methods to assess membrane fluidity [10,21,47,48]. Steadystate fluorescence polarization of TMA-DPH bound to the cell membrane was used in this study, as the dye displays in isotropic media-specific fluorescence anisotropy properties, which are changed if the free orientation of the probe is restricted by the local microenvironment: membrane fluidity is proportional to the inverse of squared anisotropy [19,30,31].…”

“…They exhibit multiple biological effects, including antioxidant, antiviral, antibacterial, anti-inflammatory, vasodilatatory, anticancer and hypoglycemic effects, and they reduce platelet aggregation, have anti-ischemic properties and improve capillary permeability and fragility [3][4][5][6][7][8]. Some flavonoids (e.g., the soy isoflavone subgroup) induce significant effects on erythrocyte membrane fluidity and deformability, affect the cellular mechanics and cause some endocrine perturbations [9,10]. Epidemiological studies have also revealed that a flavonoid-rich diet correlates with increased longevity and decreased incidence of cardiovascular diseases [3,[11][12][13][14].…”

Positive effects of naringenin on near-surface membrane fluidity in human erythrocytes

“…It has been proposed that membrane tension/fluidity represents one of the crucial definers of the cell mechanical status (4,5) and determines cell rheological properties (26). When it comes to erythrocytes, these properties reflect their ability to elastically modify shape in order to functionally pass through the narrow vessels (26), especially in hypertension or atherosclerosis.…”