Alessandra Bitto

Effects of the Phytoestrogen Genistein on Bone Metabolism in Osteopenic Postmenopausal Women: A Randomized Trial

Context Women seeking alternative treatments to preserve bone often use phytoestrogens, but evidence of their effectiveness is lacking. Phytoestrogens are found in soy products. Genistein is a phytoestrogen with a structure similar to that of 17-estradiol. Contribution This randomized trial compared genistein, 54 mg/d, with placebo for 24 months in 389 osteopenic postmenopausal women. Increases in bone mineral density were greater with genistein than with placebo. Genistein also had favorable effects on markers of bone metabolism. Genistein did not increase endometrial thickness, but it did cause gastrointestinal side effects. Implications Genistein appears to have a favorable effect on markers of bone health in osteopenic postmenopausal women. Studies of its effect on fractures are needed. The Editors Postmenopausal osteoporosis is caused by a sharp decrease in estrogen levels that leads to an increased rate of bone remodeling (13). Currently available treatments for postmenopausal osteoporosis include hormone replacement therapy; calcitonin; bisphosphonates; and selective estrogen receptor modulators, such as raloxifene (4, 5). Although hormone replacement therapy is effective in reducing postmenopausal bone loss (68), it is associated with a higher risk for breast, endometrial, and ovarian cancer; cardiovascular disease; venous thromboembolism; and stroke (810). Epidemiologic data indicate that women who ingest high amounts of phytoestrogens, particularly isoflavones in soy products, have less risk for osteoporosis than do those who consume a typical Western diet (1113). Consequently, many women use phytoestrogens to maintain bone density. Genistein, an isoflavone phytoestrogen that is abundant in soybean products, structurally resembles 17-estradiol (14). As a natural selective estrogen receptor modulator, genistein may positively regulate bone cell metabolism without harmful estrogenic activity in the breast and uterus. This safe profile results from the greater affinity of genistein for estrogen receptor-, which is more abundant in bone, than for estrogen receptor-, which is abundant in reproductive tissue. Observational studies suggest that postmenopausal Asian women who consume diets high in isoflavones have a lower rate of fracture than that in other groups (15, 16). However, the mechanism of action of genistein on bone is not yet fully understood. In postmenopausal women, treatment with genistein (54 mg/d) increased bone mineral density (BMD) at the lumbar spine and femoral neck with no clinically significant adverse effects on the breast and uterus (17). In the same cohort, genistein decreased the ratio of soluble receptor activator of nuclear factor-B ligand to osteoprotegerin, which may partly account for its positive effects on BMD (18). These investigations were the first to evaluate the effects of purified, standardized genistein on bone health, but they were short in duration and included only 90 patients. One published trial assessed the effect of isoflavones on BMD in postmenopausal women, but it compared isoflavone-rich soy milk (containing only a small amount of genistein) with natural transdermal progesterone (19). Other studies of pure genistein from our research group have focused on cardiovascular outcomes or menopausal symptoms rather than on bone health (2022). We performed a randomized, placebo-controlled trial of the effects of pure genistein on bone density and bone metabolism over 24 months in a larger cohort of osteopenic postmenopausal women. Methods Design and Setting The study protocol is consistent with the principles of the Declaration of Helsinki, and participants gave written informed consent. Participants were recruited from women reporting to the Center for Osteoporosis in the Department of Internal Medicine and the Center for Menopause in the Department of Obstetrical and Gynecological Sciences, University of Messina (Messina, Italy), and to the Department of Medical Physiopathology, University La Sapienza (Rome, Italy). Three hundred eighty-nine women met the inclusion criteria and agreed to participate (Figure 1). Figure 1. Study flow diagram. Participants Participants were women 49 to 67 years of age who had been postmenopausal for at least 12 months at baseline, were in good general health, had not had a menstrual period in the preceding year, had not undergone surgically induced menopause, and had a follicle-stimulating hormone level greater than 50 IU/L and a serum 17-estradiol level of 100 pmol/L or less (27 pg/mL). At the start of the study, a complete family history was obtained, physical examination and laboratory evaluation (chemical analytes and hematologic measurements) were performed, and BMD was measured at the lumbar spine and femoral neck. Exclusion criteria were clinical or laboratory evidence of confounding systemic diseases, such as cardiovascular, hepatic, or renal disorders; coagulopathy; use of oral or transdermal estrogen, progestin, androgens, selective estrogen receptor modulators, or other steroids; use of biphosphonates, cholesterol-lowering therapy, or cardiovascular medications (including antihypertensive drugs) in the preceding 6 months; smoking habit of more than 2 cigarettes daily; treatment in the preceding year with any drug that could have affected the skeleton; family history of estrogen-dependent cancer; and BMD at the femoral neck greater than 0.795 g/cm2 (which corresponds to a T-score of 1.0 SD). Randomization and Intervention We assigned patients to groups by using a computer-generated randomization sequence with a permuted block size of 4, stratified by center. After a 4-week stabilization period during which participants received a standard low-soy, reduced-fat diet, participants were assigned to receive genistein (n= 198), 54 mg/d in 2 tablets (Laboratori Plants, Messina, Italy), or placebo (n= 191) (Figure 1). The biological effects of phytoestrogen intake are described elsewhere (23). No patient withdrew from the study during the stabilization period. The purity of genistein was 98%. Placebo and genistein tablets were identical in appearance and taste. Both genistein and placebo tablets contained calcium carbonate (500 mg) and vitamin D (400 IU). All participants were counseled on an isocaloric, reduced-fat diet composed of 25% to 30% energy from fat, less than 10% energy from saturated fatty acids, 55% to 60% energy from carbohydrates, and 15% energy from protein, with a cholesterol intake less than 300 mg/d and fiber intake of 35 g/d or greater. Recommended daily caloric intake was based on body size and was calculated by using the HarrisBenedict equation. We used this diet during the stabilization period to ensure that all participants had the same energy intake and to avoid interference with the lipid profile. The intake of soy products, legumes, or other nutrient supplements was prohibited. The isoflavone intake before randomization, as assessed by using a food-frequency questionnaire, was 1 to 2 mg/d. This intake has been shown to be typical in Western populations (24). Participants used this diet throughout the study, and adherence was reinforced by a nutritionist. Diet and body mass index were evaluated in all participants during follow-up. Primary Outcome The BMD at the anteroposterior lumbar spine and femoral neck was measured by using dual-energy x-ray absorptiometry (Hologic QDR 4500 W, Technologic, Turin, Italy) at baseline and after 12 and 24 months of treatment. The instrument was calibrated daily according to the manufacturers instructions. Reproducibility was calculated as a coefficient of variation obtained by weekly measurements of a standard phantom on the instrument and by repeated measurements obtained in 3 patients of different ages. The coefficient of variation of our instrument is 0.5% with the standard phantom; in vivo, we calculated a coefficient of variation of 1.1% for the lumbar spine and 1.5% for the femoral neck. Secondary Outcomes Bone Resorption Markers At baseline, 12 months, and 24 months, a 2-hour fasting morning urine sample was collected at the same time of day to assess urinary excretion of pyridinium crosslinks (pyridinoline and deoxypyridinoline). Pyridinoline (normal range, 26 to 91 pmol/mol creatinine) and deoxypyridinoline (normal range, 3 to 21 pmol/mol creatinine) were measured by using high-performance liquid chromatography (Bio-Rad Laboratories, Hercules, California). Bone Formation and Bone Growth Markers and Other Variables After an overnight fast, venous blood samples were collected between 8 a.m. and 9 a.m. through a polyethylene catheter inserted in a forearm vein. The serum was separated from the blood corpuscles by centrifugation and kept frozen at 70C until analysis for bone formation and bone growth markers, calcium, intact parathyroid hormone, 25-hydroxyvitamin D3, 17-estradiol, follicle-stimulating hormone, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. Serum bone-specific alkaline phosphatase (normal range, 8.5 to 17.9 g/L) and insulin-like growth factor I (normal range, 9.6 to 21.2 nmol/L) were measured by using an immunoenzymatic assay (Pantec, Turin, Italy). Serum calcium (normal range, 2.25 to 2.75 mmol/L [9 to 11 mg/dL]), serum phosphorus (normal range, 1.13 to 1.45 mmol/L [3.5 to 4.5 mg/dL]), and urinary creatinine (130 to 220 molkg1d1 [14.71 to 24.89 mg/kg of body weight per day]) were measured by using automated routine procedures. Parathyroid hormone (normal range, 12 to 100 pg/dL), 25-hydroxyvitamin D3 (normal range, 1.25 to 7.5 nmol/L), and follicle-stimulating hormone (normal range, 21 to 153 IU/L in the postmenopausal phase) were measured by using high-performance liquid chromatography (Bio-Rad Laboratories). 17-Estradiol (normal range, 37 to 110 pmol/L in the postmenopausal phase) was evaluated by using a solid-phase immunoassay (Roche Diagnostics, Monza, Italy). Total cholesterol,

Nuclear factor kappa-B blockade reduces skeletal muscle degeneration and enhances muscle function in Mdx mice

Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease due to a mutation in the dystrophin gene and the consequential protein deficiency in muscle. How the lack of the sarcolemmal protein dystrophin gives rise to the final disease status is still not clear. Several evidences suggest a role of nuclear factor kappa-B (NF-kappaB), a pleiotropic transcription factor, in muscle degeneration and regeneration in DMD patients and mdx mice. We investigated the effects of NF-kappaB blocking by pyrrolidine dithiocarbamate (PDTC), a well-known NF-kappaB inhibitor, on dystrophic process in mdx mice. Five-week-old mdx and wild-type mice received three times a week for 5 weeks either PDTC (50 mg/kg) or its vehicle. PDTC treatment: (i) increased forelimb strength (+20%; P < 0.05) and strength normalized to weight (+24%; P < 0.05) and a decreased fatigue percentage (-61%; P < 0.05) in mdx mice, (ii) blunted the augmented NF-kappaB nuclear binding activity and the enhanced TNF-alpha expression in dystrophic muscles (P < 0.01), (iii) at a quantitative morphological evaluation of extensor digitorum longus (EDL) and biceps muscles, increased area with normal fibers (P < 0.05, in EDL), reduced muscle necrosis (P < 0.05 in biceps; P < 0.01 in EDL), and enhanced muscle regeneration (P < 0.01, in biceps). Our data support the hypothesis that NF-kappaB contributes to the perpetuation of the dystrophic damage and show that its blockade produces beneficial effects on functional, biochemical, and morphological parameters in mdx mice. Most importantly, these new findings may have clinical implications for the pharmacological treatment of patients with DMD.

Effects of the phytoestrogen genistein on hot flushes, endometrium, and vaginal epithelium in postmenopausal women: a 2-year randomized, double-blind, placebo-controlled study.

Objective: To evaluate in a 24-month, prospective, randomized, double-blind, placebo-controlled study whether pure administration of the phytoestrogen genistein (54 mg/d) might reduce the number and severity of hot flushes in postmenopausal women, with no adverse effect on the endometrium and vagina. Methods: A total of 389 participants met the parent study criteria and were randomly assigned to receive the phytoestrogen genistein (n = 198) or placebo (n = 191). About 40% of participants in both groups did not experience hot flushes, and the evaluation was performed in a subgroup of 236 participants (genistein, n = 119; placebo, n = 117). Reductions from the baseline in the frequency and severity of hot flushes were the principal criteria of efficacy. Endometrial thickness was evaluated by ultrasonography. The maturation value was also used to determine hormonal action on the vaginal cells. Results: There were no significant differences in vasomotor symptoms between groups at the baseline (4.4 ± 0.33 hot flushes per day in the genistein group and 4.2 ± 0.35 hot flushes per day in the control group). After 12 months of genistein therapy, there was a significant reduction (−56.4%) in the mean number of hot flushes, with a significant difference compared with the control group. After 24 months, there was no further decrease in the number of hot flushes in both groups. No significant difference was found in mean endometrial thickness and the maturation value score between the two groups, either at the baseline or after 24 months. Conclusions: The phytoestrogen genistein has been shown to be effective on vasomotor symptoms without an adverse effect on the endometrium and vagina, but after the first year, there was no further improvement in the decrease in hot flushes.

Breast Safety and Efficacy of Genistein Aglycone for Postmenopausal Bone Loss: A Follow-Up Study

CONTEXT Genistein aglycone improves bone metabolism in women. However, questions about the long-term safety of genistein on breast as well as its continued efficacy still remain. OBJECTIVE We assessed the continued safety profile of genistein aglycone on breast and endometrium and its effects on bone after 3 yr of therapy. DESIGN The parent study was a randomized, double-blind, placebo-controlled trial involving 389 osteopenic, postmenopausal women for 24-months. Subsequently, a subcohort (138 patients) continued therapy for an additional year. PATIENTS AND INTERVENTIONS Participants received 54 mg of genistein aglycone daily (n = 71) or placebo (n = 67). Both treatment arms received calcium and vitamin D(3) in therapeutic doses. MAIN OUTCOMES Mammographic density was assessed at baseline, 24 and 36 months by visual classification scale and digitized quantification. BRCA1 and BRCA2, sister chromatid exchange, and endometrial thickness were also evaluated. Lumbar spine and femoral neck bone mineral density were also assessed. Secondary outcomes were biochemical levels of bone markers. RESULTS After 36 months, genistein did not significantly change mammographic breast density or endometrial thickness, BRCA1 and BRCA2 expression was preserved, whereas sister chromatid exchange was reduced compared with placebo. Bone mineral density increases were greater with genistein for both femoral neck and lumbar spine compared to placebo. Genistein also significantly reduced pyridinoline, as well as serum carboxy-terminal cross-linking telopeptide and soluble receptor activator of NF-kappaB ligand while increasing bone-specific alkaline phosphatase, IGF-I, and osteoprotegerin levels. There were no differences in discomfort or adverse events between groups. CONCLUSIONS After 3 yr of treatment, genistein exhibited a promising safety profile with positive effects on bone formation in a cohort of osteopenic, postmenopausal women.

Recombinant human erythropoietin improves angiogenesis and wound healing in experimental burn wounds

Objective:Erythropoietin interacts with vascular endothelial growth factor (VEGF) and stimulates endothelial cell mitosis and motility; thus it may be of importance in the complex phenomenon of wound healing. The purpose of this study was to investigate the effect of recombinant human erythropoietin (rHuEPO) on experimental burn wounds. Design:Randomized experiment. Setting:Research laboratory. Subjects:C57BL/6 male mice weighing 25–30 g. Interventions:Mice were immersed in 80°C water for 10 secs to achieve a deep-dermal second degree burn. Animals were randomized to receive either rHuEPO (400 units/kg/day for 14 days in 100 &mgr;L subcutaneously) or its vehicle alone (100 &mgr;l/day distilled water for 14 days subcutaneously). On day 14 the animals were killed. Burn areas were used for histologic examination, evaluation of neoangiogenesis by immunohistochemistry, and expression (Western blot) of the specific endothelial marker CD31 as well as quantification of microvessel density, measurement of VEGF wound content (enzyme-linked immunosorbent assay), expression (Western blot) of endothelial and inducible nitric oxide synthases, and determination of wound nitric oxide (NO) products. Measurements and Main Results:rHuEPO increased burn wound reepithelialization and reduced the time to final wound closure. These effects were completely abated by a passive immunization with specific antibodies against erythropoietin. rHuEPO improved healing of burn wound through increased epithelial proliferation, maturation of the extracellular matrix, and angiogenesis. The hematopoietic factor augmented neoangiogenesis as suggested by the marked increase in microvessel density and by the robust expression of the specific endothelial marker CD31. Furthermore, rHuEPO enhanced the wound content of VEGF caused a marked expression of endothelial and inducible nitric oxide synthases and increased wound content of nitric oxide products. Conclusions:Our study suggests that rHuEPO may be an effective therapeutic approach to improve clinical outcomes after thermal injury.

Flavocoxid, a dual inhibitor of cyclooxygenase and 5‐lipoxygenase, blunts pro‐inflammatory phenotype activation in endotoxin‐stimulated macrophages

Background and purpose:  The flavonoids, baicalin and catechin, from Scutellaria baicalensis and Acacia catechu, respectively, have been used for various clinical applications. Flavocoxid is a mixed extract containing baicalin and catechin, and acts as a dual inhibitor of cyclooxygenase (COX) and 5‐lipoxygenase (LOX) enzymes. The anti‐inflammatory activity, measured by protein and gene expression of inflammatory markers, of flavocoxid in rat peritoneal macrophages stimulated with Salmonella enteritidis lipopolysaccharide (LPS) was investigated.

Recombinant human erythropoietin stimulates angiogenesis and healing of ischemic skin wounds.

Wound healing in ischemic tissues such as flap margins due to inadequate blood supply is still a source of considerable morbidity in surgical practice. Adequate tissue perfusion is particularly important in wound healing. We investigated the effects of recombinant human erythropoietin (rHuEPO) on wound healing in an ischemic skin wound model. Sixty-three Sprague-Dawley rats were used. Normal incisional wound and H-shaped double flaps were used as the wound models. Animals were treated with rHuEPO (400 IU/kg) or its vehicle. Rats were killed on different days (3, 5, and 10 days after skin injury) and the wounded skin tissues were used for immunohistochemistry and for analysis of vascular endothelial growth factor content and collagen content. Tissue transglutaminase immunostaining of histological specimens was used as a vascular marker to determine the level of microvessel density. The results showed a higher level of vascular endothelial growth factor protein and an increased microvessel density in ischemic wounds with rHuEPO treatment than the normal incisional wounds and ischemic control wounds. Collagen content was higher in the incisional wounds and in the ischemic wounds with rHuEPO treatment compared with the ischemic control wounds. Our results suggest that erythropoietin may be an effective therapeutic approach in improving healing in ischemic skin wounds.

VEGF overexpression via adeno-associated virus gene transfer promotes skeletal muscle regeneration and enhances muscle function in mdx mice

Vascular endothelial growth factor (VEGF) is a major regulator of physiological and pathological angiogenesis. Recently it was reported that the delivery of VEGF using recombinant adeno‐associated virus (rAAV) vectors reduces muscle damage and promotes muscle regeneration in different experimental models of muscle necrosis. We demonstrate that intramuscular administration of rAAV‐VEGF improved pathophysiology of the mdx mouse, a model of Duchenne muscular dystrophy (DMD). One month after injection, rAAV‐VEGF‐treated muscles showed augmented expression of VEGF and immu‐nolocalization of its receptor, VEGFR‐2. VEGF‐treated mdx mice showed increased forelimb strength and strength normalized to weight. Treatment reduced necrotic fibers area and increased regenerating fibers area with an augmented number of myoge‐nin‐positive satellite cells and myonuclei, and of developmental myosin heavy chain‐positive fibers. Only the regenerating area showed increased capillary density. This study provides novel evidence of a VEGF beneficial effect in mdx mice that is exerted mainly by a proregenerative and angiogenic effect. It opens new therapeutic prospectives in DMD and other types of muscular disorders.—Messina S., Mazzeo, A., Bitto, A., Aguennouz, M., Migliorato, A., De Pasquale M. G., Minutoli, L., Altavilla, D., Zentilin L., Giacca, M., Squadrito, F., Vita G. VEGF overexpression via adeno‐associated virus gene transfer promotes skeletal muscle regeneration and enhances muscle function in mdx mice. FASEB J. 21, 3737–3746 (2007)

Activation of the cholinergic anti-inflammatory pathway reduces NF-kappab activation, blunts TNF-alpha production, and protects againts splanchic artery occlusion shock.

ABSTRACT The cholinergic anti-inflammatory pathway has not yet been studied in splanchnic artery occlusion (SAO) shock. We investigated whether electrical stimulation (STIM) of efferent vagus nerves suppresses the inflammatory cascade in SAO shock. Animals were subjected to clamping of the splanchnic arteries for 45 min, followed by reperfusion. This surgical procedure resulted in an irreversible state of shock (SAO shock). Sham-operated animals were used as controls. Two minutes before the start of reperfusion, rats were subjected to bilateral cervical vagotomy (VGX) or sham surgical procedures. Application of constant voltage pulses to the caudal vagus ends (STIM: 5 V, 2 ms, 6 Hz for 15 min, 5 min after the beginning of reperfusion) increased survival rate (VGX + SAO + Sham STIM = 0% at 4 h of reperfusion; VGX + SAO + STIM = 90% at 4 h of reperfusion), reverted the marked hypotension, inhibited I&kgr;B&agr; liver loss, blunted the augmented nuclear factor-&kgr;B activity, decreased hepatic tumor necrosis factor (TNF)-&agr; mRNA (VGX + SAO + Sham STIM = 1.0 ± 1.9 TNF-&agr;/glyceraldehyde-3-phosphate dehydrogenase ratio; VGX + SAO + STIM = 0.3 ± 0.2 TNF-&agr;/glyceraldehyde-3-phosphate dehydrogenase ratio), reduced plasma TNF-&agr; (VGX + SAO + Sham STIM = 118 ± 19 pg/mL; VGX + SAO + STIM = 39 ± 8 pg/mL), ameliorated leukopenia, and decreased leukocyte accumulation, as revealed by means of myeloperoxidase activity in the ileum (VGX + SAO + Sham STIM = 7.9 ± 1 U/g tissue; VGX + SAO + STIM = 3.1 ± 0.7 U/g tissue) and in the lung (VGX + SAO + Sham STIM = 8.0 ± 1.0 U/g tissue; VGX + SAO + STIM = 3.2 ± 0.6 U/g tissue). Chlorisondamine, a nicotinic receptor antagonist, abated the effects of vagal stimulation. Our results show a parasympathetic inhibition of nuclear factor-&kgr;B and TNF-&agr; in SAO shock.

Simvastatin enhances VEGF production and ameliorates impaired wound healing in experimental diabetes

Statins have different effects beyond cholesterol reduction and stimulate angiogenesis. We investigated the effect of simvastatin in diabetes-related healing defects. An incisional skin wound model produced on the back of female diabetic mice (db(+)/db(+)) and their normoglycemic littermates (db(+)/(+)m) was used. Animals were treated daily either with simvastatin (5 mg/(kgi.p.)) or vehicle. Mice were killed on different days (3, 6 and 12 after skin injury) for measurement of vascular endothelial growth factor (VEGF) mRNA and protein expression, to assess histologically the healing process and to evaluate wound breaking strength and angiogenesis by CD31 immunostaining. Simvastatin administration in diabetic mice increased VEGF mRNA (simvastatin=4.8+/-0.6n-fold/beta-actin; vehicle=2.3+/-0.4n-fold/beta-actin) and protein expression (simvastatin=5+/-0.7 integrated intensity; vehicle=2.2+/-0.3 integrated intensity) and enhanced nitric oxide wound content at day 6. Additionally, the statin augmented breaking strength and PECAM-1 immunostaining at day 12. Finally, simvastatin administration restored the impaired wound healing process in diabetic mice. Similar results were obtained in normoglycaemic mice. Passive immunization with anti-VEGF antibody (10 microg/mouse) completely abrogated the beneficial effects of simvastatin on healing in diabetic mice. Simvastatin has potential application in diabetes-related wound healing disorders.