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The use of the antidepressant drug chlorpromazine (CPZ) is linked to the occurrence of oxidative stress in some brain structures. Thus, overcoming the side effects of CPZ is of great importance. Because agmatine (AGM) can act as a free radical scavenger, it is an interesting compound as an adjunct to CPZ therapy. The aim of our study was to investigate the enzymatic parameters of oxidative stress in the hippocampus and striatum of rats after CPZ treatment, and the potential protective effects of AGM. Rats were injected as follows with (i) 1 mL/kg b.w. saline; (ii) a single intraperitoneal (i.p.) dose of CPZ (38.7 mg/kg); (iii) CPZ (38.7 mg/kg) and AGM (75 mg/kg); (iv) AGM (75 mg/kg). CPZ induced an increase in superoxide anion radical (O2 •-) concentration, while the activities of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR), were lowered in both the hippocampus and striatum. Cotreatment with CPZ and AGM protected the examined brain structures by reversing the antioxidant enzyme activities to the control values. Following CPZ treatment, the effects were more pronounced for SOD and GPx in the hippocampus, and for SOD, CAT and GPx in the striatum. The full effect of restored superoxide production was achieved in the striatum, which points to the role of CAT. The obtained results suggest that CPZ in combination with AGM may be considered as a new treatment strategy.

We examined whether isoflavones interfere with thyroid homeostasis, increase hepatic thyroid hormone concentrations and affect cholesterol metabolism in middle-aged (MA) male rats. Thirteen-month-old Wistar rats were injected subcutaneously with 35 mg/kg b.w./day of genistein, daidzein or vehicle (controls) for four weeks. Hepatic Dio1 gene expression was up-regulated by 70% (p < 0.001 for both) and Dio1 enzyme activity increased by 64% after genistein (p < 0.001) and 73% after daidzein treatment (p < 0.0001). Hepatic T3 was 75% higher (p < 0.05 for both), while T4 increased only after genistein treatment. Serum T4 concentrations were 31% lower in genistein- and 49% lower in dadzein-treated rats (p < 0.001 for both) compared with controls. Hepatic Cyp7a1 gene expression was up-regulated by 40% after genistein and 32% after daidzein treatment (p < 0.05 for both), in agreement with a 7α-hydroxycholesterol increase of 50% (p < 0.01) and 88% (p < 0.001), respectively. Serum 24- and 27-hydroxycholesterol were 30% lower (p < 0.05 for both), while only 24-hydroxycholesterol was decreased in the liver by 45% after genistein (p < 0.05) and 39% (p < 0.01) after dadzein treatment. Serum concentration of the cholesterol precursor desmosterol was 32% (p < 0.05) lower only after dadzein treatment alone, while both isoflavones elevated this parameter in the liver by 45% (p < 0.01). In conclusion, isoflavones increased T3 availability in the liver of MA males, despite decreasing serum T4. Hepatic increase of T3 possibly contributes to activation of the neutral pathway of cholesterol degradation into bile acids in the liver. While isoflavones obviously have the potential to trigger multiple mechanisms involved in cholesterol metabolism and oxysterol production, they failed to induce any hypocholesterolemic effect.

In a series of our previous works, we revealed the beneficial effects of applied soy isoflavones (genistein or daidzein) on the wide context of corticosteroidogenesis in vivo, in a rat model of the andropause. Soy isoflavones decreased the circulating levels of pituitary adrenocorticotropic hormone, inhibited aldosterone secretion, as well as corticosterone production and secretion, but stimulated dehydroepiandrosterone secretion, all in andropausal rats. In vitro studies indicate that the mechanism underlying these hormonal changes relies on inhibition of the pituitary tyrosine kinase and adrenocortical 3β-hydroxysteroid dehydrogenase enzymes by soy isoflavones. Although the clinical studies are in their infancy, the opinion is that genistein and daidzein have therapeutic potential for the safe treatment of ageing-caused androgen deprivation and glucocorticoid excess with related metabolic/hemodynamic issues in males. Our accumulated experience and knowledge in the field of biomedical effects of plant polyphenols have provided a platform for potential recommending the agenda to organize and accelerate experimental research aimed at producing the optimal supplementation. We hypothesize that an in vivo approach should first be exploited in the sequence of investigative steps, followed by in vitro studies and synchronously conducted molecular docking analyses. In vivo research, besides establishing the margin of exposure safety or adjustment of the correct polyphenol dose, enables identification and quantification of the metabolites of applied polyphenols in the blood. Subsequent in vitro exploitation of the metabolites and related docking analyses provide clarification of the molecular mechanisms of action of applied polyphenols. Chemical modification of the polyphenol structure or coupling it with nanoparticles might be the next step in optimizing the design of supplementation. Selected, intact or chemically-modified polyphenol molecules should be included in preclinical studies on a more closely-related species, while clinical studies would finally assess the safety and effectiveness of a polyphenol-based remedial strategy. The final supplement represents a product of an appropriate technological process, conducted in accordance with the recommendations derived from the preceding research.

Soy isoflavone genistein (Gen) exerts beneficial effects against prostate cancer cells in vitro and in vivo. However, its use as a chemoprevention/therapeutic agent is largely limited due to its low bioavailability. In this study we synthesized two variants of a new delivery system, genistein–gold nanoparticles conjugates Gen@AuNPs1 and Gen@AuNPs2, by an environmentally friendly method, using a dual role of Gen to reduce Au3+ and stabilize the formed AuNPs, with no additional component. The formation of Gen@AuNPs was confirmed via UV–Vis spectroscopy, FTIR, and Raman spectra measurements. The spherical shape and uniform size of Gen@AuNPs1 and Gen@AuNPs2 (10 ± 2 and 23 ± 3 nm, respectively), were determined by transmission electron microscopy. The nano-conjugates also varied in hydrodynamic diameter (65.0 ± 1.7 and 153.0 ± 2.2 nm) but had similar negative zeta potential (−35.0 ± 2.5 and −37.0 ± 1.6 mV), as measured by dynamic light scattering. The Gen loading was estimated to be 46 and 48%, for Gen@AuNPs1 and Gen@AuNPs2, respectively. The antiproliferative activities of GenAuNPs were confirmed by MTT test in vitro on three malignant prostate carcinoma cell lines (PC3, DU 145, and LNCaP), while selectivity toward malignant phenotype was confirmed using non-cancerous MRC-5 cells. Flow cytometric analysis showed that the inhibition on cell proliferation of more potent Gen@AuNPs1 nano-conjugate is comparable with the effects of free Gen. In conclusion, the obtained results, including physicochemical characterization of newly synthesized AuNPs loaded with Gen, cytotoxicity, and IC50 assessments, indicate their stability and bioactivity as an antioxidant and anti-prostate cancer agent, with low toxicity against human primary cells. © 2021 Elsevier B.V.

International audience; A growing population of elderly people consume citrus flavanones, naringenin, and hesperetin in the form of fruits or juices. Flavanones are bioactives with potent antioxidant properties and have potential in slowing down the aging process. Because flavanones exert controversial effects on pituitary-thyroid functioning, our study on the old-aged rat model aimed to elucidate the mechanism by which naringenin and hesperetin affect this axis. Naringenin and hesperetin increased the Sirt1 mRNA level by 91 and 71% (p < 0.05), which was followed by increased Sirt1 expression by 20 and 15% (p < 0.05), respectively. Only naringenin decreased thyroid-stimulating hormone expression by 20% (p < 0.05). Thyroid peroxidase protein expression was upregulated after naringenin or hesperetin by 62 and 43% (p < 0.05), respectively. Naringenin lowered mRNA levels of Tpo, Sod1, Sod2, Cat, and Nrf2 by 50, 32, 45, 35, and 42% (p < 0.05), respectively, and increased Gpx by 54% (p < 0.05), while hesperetin decreased Sod1 and Sod2 mRNA levels by 46 and 55% (p < 0.05), respectively. Naringenin increased the protein expressions of Nrf2 and SOD2 by 58 and 50% (p < 0.05), respectively, and decreased SOD1 expression by 48% (p < 0.05), while hesperetin protein decreased expressions of SOD1 and Nrf2 by 63 and 32% (p < 0.05), respectively. Altogether, our findings suggest that citrus flavanones contribute to restoring the impaired thyroid functioning in the old-aged rats.

The aim of the study was to examine the potential of the principal soy isoflavones, genistein and daidzein, or isoflavone rich soy extract to recover pituitary castration cells in orchidectomized adult male rats in comparison with the effects of estradiol. Two weeks post orchidectomy (Orx), animals received estradiol-dipropionate, genistein, daidzein or soy extract subcutaneously for 3 weeks. Control sham-operated (So) and Orx rats received just the vehicle. Changes in the volumes of pars distalis, of individual follicle-stimulating hormone (FSH) and luteinizing hormone (LH) containing cells, their volume, numerical density and number were determined by unbiased design-based stereology. The intracellular content of βFSH and βLH was estimated by relative intensity of fluorescence (RIF). Orchidectomy increased all examined stereological parameters and RIF. Compared to Orx, estradiol increased the volume of pars distalis, but reversed RIF and all morphometric parameters of gonadotropes to the level of So rats, except their number. Treatments with purified isoflavones and soy extract decreased RIF to the control So level, expressing an estradiol-like effect. However, the histological appearance and morphometrical features of gonadotropes did not follow this pattern. Genistein increased the volume of pars distalis, decreased the volume density of LH-labeled cells and raised the number of gonadotropes. Daidzein decreased the cell volume of gonadotropic cells but increased their number and numerical density. Soy extract induced an increase in number and numerical density of FSH-containing cells. Therefore, it can be concluded that soy phytoestrogens do not fully reverse the Orx-induced changes in pituitary castration cells. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc.

Citrus flavanones naringenin (NAR) and hesperetin (HES) are potent antioxidants that may contribute to maintenance of health at old age by improving cardiovascular and metabolic status. However, they may also affect thyroid hormone economy. Keeping in mind impaired thyroid function at older age, in this study we tested wheather NAR or HES administration potentiate this decline. NAR or HES were administrated orally (15 mg/kg) to male 24-month-old Wistar rats during 4 Weeks. Control groups received vehicle, sunflower oil. Qualitative and quantitative immunohistochemical and immunofluorescent expression of specific proteins and stereological analyses of thyroid tissue were performed. Thyroid stimulating hormone (TSH) and total thyroxine (T-4) concentrations were measured in serum. Thyroid parenchyma of both flavanone-treated groups was characterized by lower (p LT 0.05) absolute and relative volume of luminal colloid, accompanied by elevated (p LT 0.05) relative volume of stroma in comparison with the controls. No hypertrophy or absolute thyroid volume change was detected. Intensity of immunopositive signal for thyroglobulin (Tg) and T-4 bound to Tg (T-4-Tg) increased (p LT 0.05) in the colloid of thyroid follicles after both flavanone treatments. Serum TSH increased (p LT 0.05) after NAR, while T-4 remained unchanged after both treatments. In conclusion, NAR elevated serum TSH in old-aged males, thus being more potent than HES in altering pituitary-thyroid axis. However, changes in thyroid structure, namely moderate colloid depletion and higher Tg and T-4-Tg protein expressions after both treatments, indicate preserved capacity of the gland to compensate flavanone interfering, and maintain T-4 production in old-aged males. (C) 2017 Elsevier GmbH. All rights reserved.

The authors (Vladimir Ajdzanovic, Ivana Jaric, Dragan Milenkovic and Verica Milosevic) are participating in the COSTAction FA 1403 POSITIVe (Inter individual variation in response to consumption of plant food bioactives and determinants involved),supported by COST (European Cooperation in Science and Technology). We are grateful to Mr. Hinko Sauter (“Swiss-ConceptSciences” d.o.o., Belgrade, Serbia) for additional technical support and to Mrs. Maja R. Vojvodi´c for language correction of the manuscript; Diosgenin, a steroidal sapogenin of natural origin, has demonstrated benefits when it comes to the treatment of malignancies, cardiovascular issues and menopausal symptoms. In this study, we investigated the histological changes of the adrenal gland after diosgenin application in a rat model of the menopause. Middle-aged, acyclic female Wistar rats were divided into control (C; n=6) and diosgenin treated (D; n=6) groups. Diosgenin (100mg/kg b.w./day) was orally administered for four weeks, while C group received the vehicle alone. A histological approach included design-based stereology, histochemistry and immunohistochemistry. The adrenal cortex volume decreased in D females by 15% (p

Introduction and Aim Daidzein application may represent an effective and less harmful alternative to indicated, classical estrogenization of ageing men. The aim of this study was to perform structural and hormonal analysis of the adrenal cortex, after estradiol or daidzein supplementation in a rat model of the andropause. Material and methods Middle-aged Wistar rats were divided into sham operated (SO; n = 8), orchidectomized (Orx; n = 8), estradiol treated orchidectomized (Orx + E; n = 8) and daidzein treated orchidectomized (Orx + D; n = 8) groups. Estradiol (0.625 mg/kg b.m./day) or daidzein (30 mg/kg b.m./day) were administered subcutaneously for three weeks, while the SO and Orx groups received the vehicle alone. Set objectives were achieved using stereology, histochemistry/immunohistochemistry, immunoassays and ultrastructural analysis. Results Both estradiol and daidzein treatment significantly increased volumes of the zona glomerulosa cell and nuclei, but decreased circulating aldosterone levels. Estradiol markedly increased volumes of the zona fasciculata cell and nuclei in parallel with significant decrease of the adrenal tissue level of corticosterone, while daidzein significantly decreased both the adrenal and circulating levels of corticosterone. Serum DHEA level and volumes of the zona reticularis cell and nuclei significantly increased upon estradiol treatment, whereas daidzein even stronger increased the circulating level of DHEA. Shunting of the corticosteroidogenesis pathways towards adrenal androgens production, after the treatments, corresponded to the ultrastructural findings and zonal capillary network rearrangements. Conclusions Given the coherence of its effects and relative safety, daidzein could be the remedy of choice for the treatment of ageing-caused androgen deprivation and the hypothalamo-pituitary-adrenal axis hyperfunction/related metabolic issues in males.

In this opinion article, we intend to elaborate on thyroid mediation of isoflavone effects mainly on the bone of aging males, which appears to have an important role but is still insufficiently analyzed in the existing literature. Namely, the consequences of exposure to endocrine-disrupting chemicals strongly depend on the timing of interaction and life stages of humans and animals, so we intended to highlight the thyroid-related mechanism underlying the beneficial effect of isoflavones on aged male bone.

Prenatal glucocorticoid overexposure could largely influence pituitary-adrenal activity and anxiety-like behavior in offspring. Our aim was to study the possible potentiating effect of moderate dose of fructose – common ingredient of today’s diet – on prenatal glucocorticoid treatment-induced hypothalamo-pituitary-adrenal (HPA) axis changes. Pregnant female rats were treated with multiple dexamethasone (Dx) doses (3 x 0.5 mg/kg/b.m. Dx; 16th-18th gestational day). Half of female offspring from control and Dx treated dams were supplemented with 10% fructose solution, from weaning till adulthood. Immunohistochemistry, unbiased stereological evaluation and hormonal analysis are used to provide the morpho-functional state of pituitary and adrenal gland. Anxiety-like behavior was assessed using the light/dark box test and the elevated plus maze test. Prenatally Dx exposed females, with or without fructose consumption, had markedly reduced adrenocortical volume (p < 0.05) comparing to controls. Increased basal plasma ACTH level in these females (p < 0.05) maintained corticosterone concentration at control level produced by smaller adrenal glands. In parallel, anxiety-like behavior was shown by both tests used. In conclusion, prenatal Dx exposure cause negative psychophysiological outcome reflected in increased HPA axis activity and anxiety behavior in female offspring, while moderately increased fructose consumption failed to evoke any alteration or to potentiate effects of prenatal Dx exposure. This is the peer reviewed version of the following article: Manojlović-Stojanoski M, Nestorović N, Petković B, Balind SR, Ristić N, Trifunović S, Ajdžanović V, Filipović B, Šošić-Jurjević B, Milošević V. The effects of prenatal dexamethasone exposure and fructose challenge on pituitary-adrenocortical activity and anxiety-like behavior in female offspring. Tissue Cell. 2020;62:101309. [https://doi.org/10.1016/j.tice.2019.101309]

In a rat model of the andropause we aimed to examine the influence of daidzein, soy isoflavone, on the structure and function of parathyroid glands (PTG) and the expression levels of some of the crucial regulators of Ca2+ and Pi homeostasis in the kidney, and to compare these effects with the effects of estradiol, serving as a positive control. Middle-aged (16-month-old) male Wistar rats were divided into the following groups: sham-operated (SO), orchidectomized (Orx), orchidectomized and estradiol-treated (Orx+E; 0.625mg/kg b.w./day, s.c.) as well as orchidectomized and daidzein-treated (Orx+D; 30mg/kg b.w./day, s.c.) group. Every treated group had a corresponding control group. PTH serum concentration was decreased in Orx+E and Orx+D groups by 10% and 21% (p

The aim of the present study was to examine the morphometric characteristics of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) immunoreactive cells in the pituitaries of orchidectomized (Orx) and Orx testosterone- or estradiol-treated rats. Adult male Orx Wistar rats, 2 weeks post operation, received estradiol dipropionate (E) or testosterone propionate (T) for 3 weeks. Both controls, sham-operated (So) and Orx rats, were injected with solvent, in the same regime. Changes in the volume of pars distalis , the volumes of individual FSH- and LH-labeled cells, their numerical density and number were determined by unbiased design-based stereology. The FSH and LH intracellular content was estimated by relative intensity of fluorescence (RIF). We observed that Orx caused hyperstimulation of gonadotropic cells. Their volume, volume density, number, numerical density and intracellular hormone content significantly increased in comparison to So controls. Compared to Orx controls, T caused a significant decrease in the volume and volume density of gonadotropic cells and immunoreactive FSH and LH content in their cytoplasm. The volume of the pars distalis , the numerical density and number of gonadotropic cells were not changed as compared to Orx controls. Estradiol treatment caused a significant increase in the volume of the pars distalis , decreases in cell volume, volume and numerical density of gonadotropic cells, and FSH and LH intracellular content in comparison to Orx controls. The number of FSH-labeled cells increased. In conclusion, both T and E reversed all of the examined parameters of gonadotropic cells of Orx rats to the level of So controls, except in number. DOI: 10.2298/ABS151201070N Key words: estradiol; gonadotropic cells; orchidectomy; stereology; testosterone Received: December 1, 2015; Revised: February 17, 2016; Accepted: February 18, 2016; Published online: August 17, 2016 How to cite this article: Nestorovic NM, Trifunovic SL, Jaric IM, Manojlovic-Stojanoski MN, Ristic NM, Filipovic BR, Sosic-Jurjevic BT, Milosevic VLj. Sex steroid application reverses changes in rat castration cells: Unbiased stereological analysis. Arch Biol Sci. 2016;68(4):821-8.

As a major phytoestrogen of soy, genistein effectively prevents bone loss in both humans and rat models of osteoporosis. However, although the bone‐sparing effects of genistein are achieved directly through estrogen receptors, its mode of action on bone by modulation of other endocrine functions is not entirely clear. Thus, thyroid hormones and calcitonin (CT) have an essential influence on bone metabolism. Besides its action on bones, in this study we examined the effect of genistein on the activity of two different endocrine cell populations, thyroid follicular and C‐cells. Fifteen‐month‐old Wistar rats were either bilaterally orchidectomized (Orx) or sham‐operated (SO). Two weeks after surgery, half of the Orx rats were treated chronically with 30 mg kg(−1) b.w. genistein (Orx + G) subcutaneously (s.c.) every day for 3 weeks, while the remaining Orx rats and the SO rats were given the same volume of sterile olive oil to serve as controls. For histomorphometrical analysis of the trabecular bone microarchitecture an imagej public domain image processing programme was used. Thyroid sections were analysed histologically and stereologically after visualization of follicular and C‐cells by immunohistochemical staining for thyroglobulin and CT. Thyroid follicular epithelium, interstitium, colloid and CT‐immunopositive C‐cells were examined morphometrically. Serum concentrations of osteocalcin (OC), triiodothyronine (T(3)), thyroxine (T(4)) and CT were determined as well as urinary calcium (Ca(2+)) concentrations. Genistein treatment significantly increased cancellous bone area (B.Ar), trabecular thickness (TbTh) and trabecular number (TbN) (P

The isoflavone, daidzein is a biologically active, plant-derived compound that interacts with estrogen receptors. Data from previous studies have suggested that daidzein exerts beneficial effects in many diseases; however, as an endocrine disrupter, it may also alter the functioning of the endocrine system. Data regarding the effect of daidzein on the morphofunctional and histological parameters of the hypothalamic-pituitary-adrenal (HPA) system is still lacking. Therefore, using the newCAST stereological software, we investigated the effects of chronic (21 days) daidzein treatment on corticotropin-releasing hormone (CRH) neurons within the hypothalamus and corticotropes (ACTH cells) in the pituitary, while image analysis was employed to-examine the intensity of fluorescence of CRH in the median eminence (ME) and adrenocorticotropin hormone in the pituitary in adult orchidectomized (Ovx) rats. Circulating ACTH and corticosterone levels were also analyzed. This study showed that daidzein treatment decreased the volume density of CRH neurons within the paraventricular nucleus as well as CRH immunofluorescence in the ME. The total number of ACTH cells was decreased, while ACTH cell volume and the intensity of ACTH fluorescence were increased following daidzein treatment. Both ACTH and corticosterone blood levels were increased after daidzein administration. The results of performed experiments clearly demonstrate that volume density of CRH neurons; total number and volume of ACTH cells, as well as stress hormones levels are vulnerable to the effects of daidzein.

Soy-food and its isoflavones, genistein (G) and daidzein (D), were reported to exert mild cholesterol-lowering effect, but the underlying mechanism is still unclear. In this research, first we studied age-related alterations in hepatic cholesterol metabolism of acyclic middle-aged (MA) female rats. Then we tested if purified isoflavones may prevent or reverse these changes, and whether putative changes in hepatic thyroid hormone availability may be associated with this effect. Serum and hepatic total cholesterol (TChol), bile acid and cholesterol precursors, as well as serum TSH and T4 concentrations, hepatic deiodinase (Dio) 1 enzyme activity and MCT8 protein expression were determined by comparing data obtained for MA with young adult (YA) intact (IC) females. Effects of subcutaneously administered G or D (35 mg/kg) to MA rats were evaluated versus vehicle-treated MA females. MA IC females were characterized by: higher (p < 0.05) serum TChol, lower (p < 0.05) hepatic TChol and its biosynthetic precursors, lower (p < 0.05) hepatic 7α-hydroxycholesterol but elevated (p < 0.05) 27- and 24-hydroxycholesterol in comparison to YA IC. Both isoflavone treatments decreased (p < 0.05) hepatic 27-hydroxycholesterol, G being more effective than D, without affecting any other parameter of Chol metabolism. Only G elevated hepatic Dio1 activity (p < 0.05). In conclusion, age-related hypercholesteremia was associated with lower hepatic Chol synthesis and shift from main neutral (lower 7α-hydroxycholesterol) to alternative acidic pathway (higher 27-hydroxycholesterol) of Chol degradation to bile acid. Both isoflavones lowered hepatic 27-hydroxycholesterol, which may be considered beneficial. Only G treatment increased hepatic Dio1 activity, thus indicating local increase in thyroid hormones, obviously insufficient to induce prominent cholesterol-lowering effect. Experimental Gerontology (2017), 92: 74-81

Aging is a complex process characterized by a progressive decline in cellular function, alterations of the endocrine system and the increased incidence of thyroid diseases. Citrus flavanones naringenin (NAR) and hesperetin (HES) may contribute to maintenance of health at old age however they may also affect thyroid hormone economy. The aim of this study was to test weather NAR or HES administration alter thyroid functioning. NAR or HES were administrated orally (15 mg/kg) to male 24-month-old Wistar rats during 4 weeks. Control groups received vehicle, sunflower oil. Immunohistochemical staining of thyroglobulin (Tg), thyroxine (T4) bound to Tg (T4-Tg) and sodium iodide sysmporter (NIS) were performed. Immunopositivity of Tg or T4-Tg in thyroid follicles were measured as intensity of optical density (OD) or relative intensity of fluorescence (RIF). Thyroid stimulating hormone (TSH) and total T4 concentrations were measured in serum. After citrus flavanones treatments, thyroids showed Tg and T4-Tg immunopositivity mainly in the colloid of the follicles. The obtained results showed increased (P ! 0.05) intensity of OD for Tg and T4-Tg RIF after both flavanones treatments, while NIS expression did not change. Serum TSH increased (P ! 0.05) only after NAR, although T4 remained unchanged after both treatments. In conclusion, citrus flavanones induced stronger expression of thyroid-specific proteins in gland of old-aged males. However, only NAR elevated serum TSH, being more potent than HES. This alteration is in line with preserved capacity of the thyroid to compensate the mild interference of flavanones treatments with thyroid hormone production in old-aged males.

We previously reported that Vitex agnus-castus L. essential oil (VACEO), when administered to middle-aged males, exerts a bone-protective effect, induces silencing of locomotor activities and decreases pituitary prolactin immunopositivity. To further assess the putative endocrine effects of VACEO, we examined the pituitary-thyroid and -adrenocortical axes in our model. Sixteen-month-old Wistar rats were subcutaneously administered 60mg/kg of VACEO dissolved in sterile olive oil, while the control group received the same amount of vehicle alone for three weeks. Pituitaries, thyroids and adrenals were analyzed by qualitative and quantitative histological approaches. Concentration of thyroid stimulating hormone (TSH), total thyroxine and triiodothyronine (TH), adrenocorticotrophic hormone (ACTH), corticosterone in serum and in adrenal tissue were measured. In VACEO-treated rats, the relative volume density of pituitary thyrotrophs increased (p

This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia Grant No. 173009; This study aimed to investigate effects of citrus flavanones naringenin (NAR) and hesperetin (HES) on liver antioxidant status and membrane phospholipid composition in 24-month-old rats. NAR and HES (15 mg/kg) were administrated orally to male Wistar rats, once per day, for 4 weeks. Control group received either vehicle (sunflower oil) or remained intact. The results showed decreased (p < 0.05) activity of antioxidant enzymes (AOE), specifically catalase (CAT), superoxide dismutase (SOD) 1 and glutathione reductase (GR) in the liver of intact control old-aged rats in comparison to young intact controls. Flavanone administration to old-aged males increased (p < 0.05) examined AOE activities in comparison to vehicle-administered animals. Namely, NAR was more potent in comparison to HES regarding the increase (p < 0.05) in activities of examined antioxidant enzymes (SOD 1 and 2, glutathione peroxidase-GPx and GR) and the liver glutathione (GSH), while HES elevated (p < 0.05) only activity of CAT and GR. Both flavanones significantly decreased (p < 0.05) TBARS and improved (p < 0.05) membrane phospholipid composition in favor of n-3 PUFA and n-6/n-3 PUFA ratio. Both flavanones did not affect liver histology and reduced (p < 0.05) alanine aminotransferase and aspartate aminotransferase levels in serum. The results of this study indicate beneficial potential of citrus flavanones in the old-aged rat liver

Androgen deficiency is one of the major factors leading to the development of osteoporosis in men. Since calcitonin (CT) is a potent antiresorptive agent, in the present study we investigated the effects of androgen deficiency and subsequent testosterone and estradiol treatment on CT-producing thyroid C cells, skeletal and hormonal changes in middle-aged orchidectomized (Orx) rats. Fifteen-month-old male Wistar rats were either Orx or sham-operated (SO). One group of Orx rats received 5 mg kg(-1) b.w. testosterone propionate (TP) subcutaneously, while another group was injected with 0.06 mg kg(-1) b.w. estradiol dipropionate (EDP) once a day for 3 weeks. A peroxidase-antiperoxidase method was applied for localization of CT in the C cells. The studies included ultrastructural microscopic observation of these cells. The metaphyseal region of the proximal tibia was measured histomorphometrically using an imagej public domain image processing program. TP or EDP treatment significantly increased C cell volume (Vc), volume densities (Vv) and serum CT concentration compared with the Orx animals. Administration of both TP and EDP significantly enhanced cancellous bone area (B.Ar), trabecular thickness (Tb.Th) and trabecular number (Tb.N) and reduced trabecular separation (Tb.Sp). Serum osteocalcin (OC) and urinary Ca concentrations were significantly lower after these treatments in comparison with Orx rats. These data suggest that testosterone and estradiol treatment in Orx middle-aged rats affect calcitonin-producing thyroid C cells, which may contribute to the bone protective effects of sex hormones in the rat model of male osteoporosis.

This study aimed to examine the influence of pregnancy on responsiveness of the pituitary–adrenal (PA) axis to dexamethasone (Dx) in rats. Dams and virgins were injected with Dx in three consecutive daily doses of 1.0, 0.5, 0.5 mg/kg/bw, starting from day 16 of pregnancy, and sacrificed 24 and 72 h after termination of treatment. Immunocytochemical, morphometrical and biochemical methods were used to assess pituitary and adrenal function. Three-way ANOVA revealed Dx inhibition of the PA axis in virgin and pregnant females after 24 and 72 h. Pregnant females demonstrated a significantly lower (p

Vitex Agnus-CastusL. Essential Oil Increases Human Erythrocyte Membrane FluidityErythrocyte membrane fluidity is related to their rheologic behavior, the dynamic quality of erythrocytes, which is tempted in hypertension and atherosclerosis. An increased risk of these and other cardiovascular diseases occurs in ageing women. Menopause-related conditions are often treated with hormone replacement therapy that may increase the risk of malignancies.Vitex agnus-castusL. essential oil contains various organic compounds (monoterpenes, sesquiterpenes and terpenoids), and is increasingly used as an alternative therapy for menopausal symptoms. These components of the oil may be incorporated into cell membranes, thereby changing the membrane fluidity. The aim of this study was to determine the effects ofVitex agnus-castusessential oil on human erythrocyte membrane fluidity at graded depths. We used Electron Paramagnetic Resonance spectroscopy and fatty acid spin probes (5-doxyl stearic acid and 12-doxyl stearic acid), whose spectra depend on membrane fluidity. After treatment withVitex agnus-castusessential oil the erythrocytes had a significant (p=0.029) and reversible increase in membrane fluidity in the deeper hydrophobic membrane regions, with no change (p>0.05) in fluidity near the membrane's hydrophilic surface. These results document increased fluidity of the human erythrocyte membrane byVitex agnus-castusessential oil, and this action may be useful in patients with menopause-related hypertension and other cardiovascular conditions.

Andropause, the culminating phase of ageing in males is characterized by the decline of the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis that is responsible for somatic development. Estrogens on the other hand, assume a relevant somatic role, as well as the one in the pituitary. They are particularly interesting because of their therapeutic uses in certain common ageing-associated diseases. The aim of the present study was to examine the effects of subcutaneous treatment with estradiol, dipropionate on the immunohistomorphometric features of GH cells, in an animal model of the andropause. Sixteen-month-old Wistar rats were divided into sham-operated (SO), orchidectomized (Orx) and estradiol dipropionate-treated orchidectomized (Orx+Edp) groups. Estradiol dipropionate (0.625 mg/kg/day) was administered subcutaneously for three weeks while the SO and Orx groups received the vehicle alone. GH cells were identified by the peroxidase-antiperoxidase (PAP) immunohistochemical procedure. In the Orx+Edp group, GH cell volumes as well as the relative volume densities were significantly (p

High intake of soybean phytoestrogens, isoflavones genistein (G) and daidzein (D), has been associated with health benefits. However, isoflavones were reported to affect adversely thyroid function in the presence of other goitrogenic factors. As the thyroid gland becomes functionally impaired with age, we examined whether supplementary doses of G or D would affect morphology and function of pituitary–thyroid axis in middle-aged male rats. Sixteen-month-old orchidectomized Wistar rats were treated with 10 mg/kg of either G or D, while the control sham-operated and orchidectomized group received just the vehicle for three weeks. The animals were fed soy-free diet with increased iodine content, and killed 24 h after the last treatment. Their pituitaries and thyroids were excised and prepared for further immunohistochemical and morphometric investigation. The concentrations of thyroid-stimulating hormone (TSH), total T4 and T3, in the serum were determined. In both isoflavone-treated groups, pituitary TSH-immunopositive cells had increased cellular volume and relative volume density ( P < 0.05), as well as increased serum TSH levels ( P < 0.05) in comparison to the controls; their thyroid tissue was characterized by increased volume of thyroglobulin-immunopositive epithelium ( P < 0.05), epithelial height and index of activation rate ( P < 0.05), while the volume of luminal colloid, and total serum T4 and T3 levels decreased ( P < 0.05) in comparison to the controls. In conclusion, this study provides the first direct evidence that both G and D can induce microfollicular changes in the thyroid tissue and reduce the level of thyroid hormones in Orx middle-aged male rats, a model of andropause. This reduction consequently led to a feedback stimulation of pituitary TSH cells. The detected stimulatory effect was higher in the daidzein-treated rats.

The maintenance of erythrocyte membrane fluidity at the physiological level is an important factor affecting the ability of erythrocytes to pass through blood vessels of small luminal diameter. Genistein and daidzein, which are used as alternative therapeutics in cardiovascular conditions, can be incorporated into the cell membrane and change its fluidity. The aim of this study was to examine the effects of genistein and daidzein on erythrocyte membrane fluidity at graded depths. We used electron paramagnetic resonance (EPR) spectroscopy and fatty acid spin probes (5-DS and 12-DS) where EPR spectra were dependent on fluidity. The results showed that genistein significantly (p < 0.05) decreased erythrocyte membrane fluidity near the hydrophilic surface, while daidzein significantly (p < 0.05) increased the same parameter in deeper regions of the membrane. These data suggest that the deep fluidizing effects of daidzein on erythrocyte membranes make it a better therapeutic choice than genistein in some cardiovascular conditions. Ministry for Science of Serbia [143007B, 143016B]

Ghrelin, a growth hormone secretagogue that exerts an important role in appetite and weight regulation, participates in the activation of the hypothalamo-pituitary-adrenal (HPA) axis. Male Wistar rats (5/group) received daily for 5 days, via an ICV (intracerebroventricular) cannula, 5 microl phosphate buffered saline with or without 1 microg of rat ghrelin. Two hours after the last injection, blood and adrenal glands were collected from decapitated rats for blood hormone analyses and histologic and morphometric processing. Ghrelin treatment resulted in increased (p

Thyroid C cells hormone, calcitonine, inhibits bone resorption. We have demonstrated that daidzein treatment of orchidectomized rats (model for osteoporosis) stimulated C cells and increased trabecular bone mass. These results suggest that, besides direct action, daidzein may also affect bone structure indirectly through enhancement of thyroid C cell activity. Thyroid C cells produce calcitonin (CT) which acts as an inhibitor of bone resorption. In this study, the influence of daidzein treatment on thyroid C cells, bone structure, and bone function in orchidectomized (Orx) middle-aged rats was investigated. Sixteen-month-old Wistar rats were divided into Orx and sham-operated (SO) groups. Half the Orx rats were given subcutaneous injections of daidzein (30 mg/kg b.w./day) for 3 weeks. CT-immunopositive thyroid C cells were morphometrically analyzed. The metaphyseal region of the proximal tibia was measured histomorphometrically, and cancellous bone area (B.Ar), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.Sp) were calculated. Serum samples were analyzed for CT and osteocalcin (OC), calcium (Ca) and phosphorus concentrations, and urine samples for Ca levels. Treatment of Orx animals with daidzein significantly increased volume of C cells compared to the Orx rats. Daidzein also enhanced B.Ar, Tb.Th, and Tb.N and reduced Tb.Sp. The serum OC and urinary Ca concentrations decreased significantly in comparison with the Orx group. These findings indicate that daidzein treatment stimulates thyroid C cells, increase trabecular bone mass, and decrease bone turnover in Orx middle-aged rats, which is the model of male osteoporosis.

The soybean phytoestrogen, genistein, is increasingly consumed as an alternative therapeutic for age-related diseases, namely cardiovascular conditions, cancer and osteoporosis. Besides estrogenic/antiestrogenic action, this isoflavone exerts a prominent inhibitory effect on tyrosine kinase and the steroidogenic enzyme families, thus affecting hormonal homeostasis. The aim of this study was to examine the effects of genistein on: histomorphometric features of the adrenal cortex, blood concentrations of aldosterone, corticosterone and dehydroepiandrosterone (DHEA) and adrenal tissue corticosterone content in orchidectomized middle-aged male rats. Sixteen-month-old Wistar rats were divided into sham-operated (SO), orchidectomized (Orx) and genistein-treated orchidectomized (Orx+G) groups. Genistein (30 mg/kg/day) was administered subcutaneously for three weeks, while the control groups received the vehicle alone. The adrenal cortex was analysed histologically and morphometrically. Circulating concentrations of aldosterone, corticosterone and DHEA, as well as adrenal tissue corticosterone levels, were determined by immunoassay. When compared to the SO group, orchidectomy decreased the ZG and ZR cell volume by 43% and 29%, respectively (P < 0.05). Serum concentrations of aldosterone and DHEA were markedly lower [13% and 41%, respectively (P < 0.05)], while serum and adrenal tissue levels of corticosterone did not change after orchidectomy. Orchidectomy followed by genistein treatment increased the ZG, ZF and ZR cell volume by 54%, 34% and 77%, respectively (P < 0.05), compared to the untreated orchidectomized group. Histological analysis revealed noticeable vacuolization of the ZG and ZF cells in the Orx+G group. Serum aldosterone and corticosterone concentrations together with adrenal tissue corticosterone were 47%, 31% and 44% lower, respectively (P < 0.05), whereas serum DHEA concentration was 342% higher (P < 0.05) in this group in comparison with the Orx group. This study shows that in orchidectomized middle-aged rats, genistein can cause the shunting of metabolic pathways in the adrenals, supporting DHEA secretion and inhibiting corticosterone and aldosterone secretion. Exp Biol Med 234:148-156, 2009 Ministry of Science and Technological Development of Serbia [143007B]

The soybean phytoestrogen, genistein, is increasingly consumed as an alternative therapeutic for age-related diseases. The aim of this study was to examine the morphofunctional characteristics of adrenocorticotrophic (ACTH) cells and blood concentrations of ACTH in sham-operated, orchidectomized and genistein-treated orchidectomized, 16-month-old Wistar male rats. Genistein (10 mg/kg/day) was administered subcutaneously for three weeks, while the control groups received the vehicle alone. Orchidectomy and genistein treatment decreased the volume density of ACTH cells and reduced (p < 0.05) circulating ACTH concentrations in comparison with control groups. In conclusion, genistein modulated the morphofunctional features of ACTH cells and decreased blood ACTH levels. Ministry for Science of Serbia [143007B]

Nutritional supplements containing soybean phytoestrogens, the isoflavones genistein (G) and daidzein (D), are increasingly used as alternative therapy for osteoporosis, cancer, and cardiovascular and other diseases with a frequency that increases with advancing age. In this study we examined the effects of subcutaneous administration of either G or D on serum lipid levels in orchidectomized (Orx) and intact (IA) middle-aged male rats, which are experimental models of andropause. Sixteen-month-old Wistar rats were treated with 10 mg/kg and 30mg/kg of either G or D. The control groups received testosterone, estradiol, or vehicle for 3 weeks, after which the total serum cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), and total triglycerides (TT) were measured. Compared with the matching vehicle-treated controls, the higher doses of G and D and testosterone treatment significantly ( P < 0.05) lowered the TC and lipoprotein cholesterol levels. The greatest effect was observed regarding LDL-C in both Orx and IA males after G and D treatments, in which LDL-C decreased by more than 30%. The lower isoflavone doses induced a significant cholesterol-lowering effect ( P < 0.05) only in the Orx group. Like the estradiol treatment, the higher doses of G and D increased the TT levels in both rat models by more than 50% ( P < 0.05). The lower doses of isoflavones increased TT only in the Orx group. In male middle-aged rats, injections of higher doses of G and D decreased the serum cholesterol levels, as did testosterone injection, and brought about an increase in serum triglycerides similar to that observed after estradiol treatment.

The effects of estradiol dipropionate (EDP) or calciumglucoheptonate (Ca) on the morphology and stereology of the PRLcellsin14-month-oldWistarfemaleratswerestudied.Theanimalsweretreated daily with EDP in the dose of 0.625 mg/kg b.w. or calciumglucoheptonate(Ca;11.4mg/kgb.w.)fortwoweeks.Thecontrolswereinjected with vehicle alone by the same schedule. Mammotrophs (PRLcells) were immunocytochemically localized by the PAP method. BloodPRL concentration was determined by Delfia procedure. In animalstreated with EDP the volume of both, PRL cells and their nuclei, as wellas the volume densities were significantly (p 0.05) decreased compared to control rats. Serum concentration ofPRL was significantly increased (p 0.05) changed by 2% compared to controls. Based on theseresults, it can be concluded that EDP expresses a strong stimulatoryeffect on the morphology and function of pituitary PRL cells.Keywords:PRL,mammotrophs,estradiol,calcium,middle-aged,female rats

The effects of ovariectomy (Ovx) and of ovariectomy followed by chronic estradiol dipropionate administration (Ovx EDP) on the structure and function of the pituitary-thyroid axis were examined in the rat. Pituitary TSH cells and thyroid tissue were histologically, immunohistochemically and stereologically investigated. Serum TSH and T(4) levels were determined by RIA. Ovx did not affect pituitary weight, but subsequent treatment with EDP led to its more than two-fold increase (p

Somatopause, the complex aspect of andropause, is recognizable by reduced growth hormone - GH/insulin-like growth factor 1 axis function in the ageing male. Soy isoflavones (usually genistein and daidzein), which are known for their beneficial effects in the treatment of ageing symptoms, are active in the pituitary, as well. The immunohistomorphometric and -fluorescent characteristics of pituitary growth hormone secreting cells, in an animal model of andropause, were examined after a treatment with genistein or daidzein. Andropausal Wistar rats were divided into sham operated, orchidectomized and genistein or daidzein treated orchidectomized groups. Genistein or daidzein (30 mg/kg/day) were administered subcutaneously for three weeks, while sham operated and orchidectomized groups received the vehicle alone. Growth hormone secreting cells were identified by the peroxidase-antiperoxidase immuno-histochemical, and immuno-fluorescent procedure. The main characteristic of growth hormone secreting cells in soy isoflavones treated groups is a weaker immuno-histochemical staining and immuno-fluorescent signal compared to sham operated and orchidectomized groups. The growth hormone secreting cell volume in orchidectomized +genistein or +daidzein groups is by 13.8% and 11.9% (p

We previously reported that genistein (G) and daidzein (D) administered subcutaneously (10mg/kg) induce changes in the angio-follicular units of the thyroid gland, reduce concentration of total thyroid hormones (TH) and increase thyrotropin (TSH) in serum of orchidectomized middle-aged (16-month-old) rats. To further investigate these effects, we now examined expression levels of the thyroglobulin (Tg), thyroperoxidase (Tpo), vascular endothelial growth factor A (Vegfa) and deiodinase type 1 (Dio 1) genes in the thyroid; in the pituitary, genes involved in TH feedback control (Tsh β, Dio 1, Dio 2, Trh receptor); and in the liver and kidney, expression of T3-activated genes Dio 1 and Spot 14, as well as transthyretin (Ttr), by quantitative real-time PCR. We also analyzed TPO-immunopositivity and immunofluorescence of T4 bound to Tg, determined thyroid T4 levels and measured deiodinase enzyme activities in examined organs. Decreased expression of Tg and Tpo genes (p

Numerous studies have established a link between estrogen levels and activity of the hypothalamic pituitary adrenal (HPA) system. Considering the ``weak estrogenic{''} effect of soy isoflavones, this study was designed to evaluate the influence of soy extract treatment on some morphofunctional parameters of rat pituitary corticotropes in vivo. Adult male orchidectomized Wistar rats received estradiol-dipropionate or soy extract in oil/ethanol solvent subcutaneously for 3 weeks. Both controls, sham-operated (So) and orchidectomized (Orx) rats, were injected with solvent, in the same regime. Changes in pituitary volume, total volume, total number and volume of individual corticotropes were evaluated stereologically, while ACTH levels were determined biochemically. In comparison with So rats, estradiol treatment provoked increases (p < 0.05) of ACTH level (166\%), pituitary weight (167\%) and volume (102\%), total volume (20\%) and total number of corticotropes (18\%). In comparison to Orx, following estradiol treatment elevation (p < 0.05) of ADE level (69\%), pituitary weight (131\%) and volume (82\%), total (30\%) and individual volume (29\%) of corticotropes was observed. Soy extract treatment led to enhancement (p < 0.05) of: ACTH level (28\%), total (25\%) and individual volume (20\%) of corticotropes. It can be concluded that soy extract acts in a similar way to estradiol, but the increased activity of corticotropes was weaker. (C) 2013 Elsevier GmbH. All rights reserved. Ministry of Education and Science of Serbia {[}173009]

Endogenous androgens are involved in regulation of thyroid function and metabolism of thyroid hormones. As serum testosterone level progressively declines with age, this regulation may change. We tested how androgen deprivation, achieved by orchidectomy, affects thyroid homeostasis in middle-aged rats. Fifteen-month-old Wistar rats were orchidectomized (Orx) or sham-operated under ketamine anesthesia (15 mg/kg body weight). Five weeks after the surgery, animals were decapitated. Thyroids were used for histomorphometric and ultrastructural examinations and together with livers and pituitaries for real-time quantitative PCR and deiodinase (DIO) activity measurements. Serum testosterone, TSH, l-thyroxine (T4), and cholesterol (Chol) levels were determined. As expected, middle-aged control rats had lower (P4 compared with 3-month-old males. In the Orx middle-aged group, we detected diminished serum testosterone (P4 levels, and higher Chol level (PPDio1 gene expression and DIO1 activity were decreased (PTSHβ, Dio1, and Dio2 mRNAs did not change, while DIO2 activity decreased (P4 and TSH. However, decreased liver DIO1 and pituitary DIO2 enzyme activities indicate compensatory–adaptive changes in local T3 production.

Proper and balanced nutrition is very important in prevention and treatment of chronic diseases. Many individuals modify their diet and/or take different nutraceuticals expecting to attain optimum health, extend their lifespan and prevent diseases such as cardiovascular, cancer, osteoporosis, obesity, or diabetes type II. Based on „Japanese phenomenon“ (Adlercreutz, 1998), numerous advertisements suggest that soy-based diet, and its phytoestrogens (PE) in particular, provide protection against many chronic diseases and contribute to the long lifespan often observed in Asia. That is why soy and other phytoestrogen rich plants became increasingly popular in the U.S. and western countries in the past 30 years. Furthermore, in these countries, PEs are often consumed in its purified form, as nutritional supplements, “designed” for special medical purposes. These supplements are freely available in pharmacies, health food shops, grocery shops and are usually consumed without medical control. There is a lack of awareness that uncontrolled consumption of natural PEs may be potentially harmful to human health. Even more concerning is that some people consume supplements in excess of suggested daily dosage (Wuttke et al., 2007). The soybean (Glycine max), compared to other legumes, is richer in protein levels and quality, based on its digestibility and concentration of essential amino acids (Rand et al., 2003). It is also good source of fiber, certain vitamins and minerals, such as folate and potassium (Rochfort and Panozzo, 2007). It has very high antioxidant content, similar to fruits famous for their antioxidant activity (Galleano et al., 2010). Also, despite their high carbohydrate content, the glycemic load of soybeans is relatively low due to their low glycemic index. In addition, soy-food has high levels of iron in the form of ferritin (Lonnerdal et al., 2006). The concentration of calcium in soymilk is much lower than in cow milk, however, its absorption from soy milk is similar to that from cow milk (Reinwald and Weaver, 2010). Besides the favorable nutritional attributes, soybean contains a number of biologically active components (saponins and lunasin, phytic acids, phytosterols, trypsin inhibitors, and peptides) including isoflavones genistein (G), daidzein (D) and glycitein (Gy). As soybean phytoestrogens, isoflavones are considered the most important in prevention and treatment of hormone-dependent cancers, cardiovascular diseases, osteoporosis, menopausal symptoms and other age-related diseases. In addition, some studies suggest that soy and its isoflavones affect body weight homeostasis. Modern world is a controversy with ever-increasing obesity on one side, and a high percent of starving people around the globe, on the other side. Having that in mind, combined with

A decrease of erythrocyte membrane fluidity can contribute to the pathophysiology of hypertension. Soy products, which are used as alternative therapeutics in some cardiovascular conditions, contain various isoflavones (genistein, daidzein, and their glucosides, genistin and daidzin), which can incorporate cellular membrane and change its fluidity. The aim of this study was to examine the effects of soy extract (which generally corresponds to the soy products of isoflavone composition) on erythrocyte membrane fluidity at graded depths. We used electron paramagnetic resonance spectroscopy and fatty acid spin probes (5-DS and 12-DS), the spectra of which are dependent on membrane fluidity. After being treated with soy extract, erythrocytes showed a significant (P = 0.016) decrease of membrane fluidity near the hydrophilic surface, while there were no significant changes of fluidity in deeper hydrophobic membrane regions. These results suggest that soy products containing high levels of genistein and isoflavone glucosides may not be suitable for use in hypertension because they decrease erythrocyte membrane fluidity. Ministry of Science of the Republic of Serbia [143007B, 143016B]