Raloxifene Treatment Research Articles

162 Contribution of MPAK and NF-kB Signaling to TLR Mediated MCP-1 Secretion

Secretion of matrix metalloproteinases (MMPs) by macrophages and smooth muscle cells (SMC) may impair atherosclerotic cap integrity leading to atherosclerosis complications. Selective estrogen receptor modulators (SERMs) have favourable impact on plasma lipid levels, but their role in the prevention of atherosclerosis still remains unclear. We investigated the effects of raloxifene, a second generation SERM, on MMP expression and activity in cultured macrophages and SMC, and in rabbit carotid lesions. Human monocyte-derived macrophages were isolated from blood of healthy donors. SMC were isolated from the intima-media layers of collared rabbit carotid arteries. Cells were incubated for 24 h with increasing concentrations of raloxifene. Ovariectomized rabbits fed a 1% cholesterol-rich diet were subjected to pericarotid collar placement and treated with or without 10 mg kg−1 d−1 raloxifene for 2 weeks. In macrophages, raloxifene treatment (0.1–10 μM) significantly reduced MMP-9 gelatinolytic potential in a concentration-dependent manner, without affecting MMP-9 activation. This effect was estrogen receptor (ER)-dependent and due to the inhibition of MMP-9 promoter-driven transcription following an interaction with NF-kB pathway. Similarly, in cultured SMC, raloxifene inhibited up to 40% MMP-2 gelatinolytic activity. In vivo, raloxifene decreased the expression of MMP-2, MMP-3, and MMP-9 by intimal cells and the total gelatinolytic activity of collared carotids. These effects were accompanied by reduction of lesion size and inhibition of macrophage accumulation. Overall, results indicate that raloxifene may reduce MMPs expression and activity in macrophages and smooth muscle cells and favourably affect lesion formation.

Raloxifene Modulates Pulmonary Vascular Reactivity in Spontaneously Hypertensive Rats

Selective estrogen receptor modulators (SERMs) reduce vascular tone in the systemic circulation. Their effects on the pulmonary circulation are unknown. The present study examined the effect of oral treatment with raloxifene (a second-generation SERM) on vasomotor reactivity in pulmonary arteries from normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Pulmonary arterial rings were suspended in a multi-channel myograph, and changes in isometric tension were measured. WKY rings constricted less to U46619 than SHR rings, and the difference was eliminated after chronic treatment with raloxifene. More contraction to U46619 was obtained after inhibition of nitric oxide synthase (NOS) by L-NAME (as an index of basal NO release) in raloxifene-treated than in control SHR rings. Less U46619-induced contraction after raloxifene treatment occurred only in SHR rings with endothelium, and this effect was abolished upon removal of the endothelium. Raloxifene treatment did not enhance the contribution of basal NO to U46619-induced constriction in WKY rings. Raloxifene treatment did not modify endothelium-dependent relaxation to acetylcholine and endothelium-independent relaxation to nifedipine. The reduced relaxing sensitivity to sodium nitroprusside (SNP) in SHR rings was normalized by raloxifene treatment. Raloxifene treatment reduced CaCl2-induced tone in SHR but not in WKY rings. The results show that chronic treatment with raloxifene could improve pulmonary vascular function in hypertensive animals by (1) increasing basal NO release, (2) reducing vascular smooth muscle tone, and (3) improving the effect of NO on vascular smooth muscle in SHR. In contrast, raloxifene has little effect on vascular reactivity in pulmonary arteries from normotensive WKY rats.

Raloxifene inhibits matrix metalloproteinases expression and activity in macrophages and smooth muscle cells

Secretion of matrix metalloproteinases (MMPs) by macrophages and smooth muscle cells (SMC) may impair atherosclerotic cap integrity leading to atherosclerosis complications. Selective estrogen receptor modulators (SERMs) have favourable impact on plasma lipid levels, but their role in the prevention of atherosclerosis still remains unclear. We investigated the effects of raloxifene, a second generation SERM, on MMP expression and activity in cultured macrophages and SMC, and in rabbit carotid lesions. Human monocyte-derived macrophages were isolated from blood of healthy donors. SMC were isolated from the intima-media layers of collared rabbit carotid arteries. Cells were incubated for 24 h with increasing concentrations of raloxifene. Ovariectomized rabbits fed a 1% cholesterol-rich diet were subjected to pericarotid collar placement and treated with or without 10 mg kg −1 d −1 raloxifene for 2 weeks. In macrophages, raloxifene treatment (0.1–10 μM) significantly reduced MMP-9 gelatinolytic potential in a concentration-dependent manner, without affecting MMP-9 activation. This effect was estrogen receptor (ER)-dependent and due to the inhibition of MMP-9 promoter-driven transcription following an interaction with NF-kB pathway. Similarly, in cultured SMC, raloxifene inhibited up to 40% MMP-2 gelatinolytic activity. In vivo, raloxifene decreased the expression of MMP-2, MMP-3, and MMP-9 by intimal cells and the total gelatinolytic activity of collared carotids. These effects were accompanied by reduction of lesion size and inhibition of macrophage accumulation. Overall, results indicate that raloxifene may reduce MMPs expression and activity in macrophages and smooth muscle cells and favourably affect lesion formation.

Effect of raloxifene—a selective oestrogen receptor modulator—on kidney function in post‐menopausal women with Type 2 diabetes: results from a randomized, placebo‐controlled pilot trial

Epidemiological and experimental data suggest that activation of the oestrogen receptor pathway limits the incidence and the progression of diabetic nephropathy. We tested the hypothesis that raloxifene protects against increasing urinary albumin excretion in post-menopausal women with Type 2 diabetes in a randomized pilot clinical trial. We included 39 post-menopausal women with Type 2 diabetes and micro- or macro-albuminuria in a 6-month, double-blind, placebo-controlled trial: 20 received placebo and 19 received 60 mg raloxifene per day. The albumin : creatinine ratio (ACR) in urine was determined on three consecutive days during the week before randomization and during the week before the final visit. One patient in each group dropped out in the first 3 weeks, leaving 37 patients for the analysis (19 on placebo and 18 on raloxifene). From randomization to the final visit, mean ACR was unchanged in the placebo group {277 microg/mg (67; 651) [median (interquartile range)] vs. 284 microg/mg (79; 1508)} but decreased slightly in the raloxifene group [376 microg/mg (67; 615) vs. 243 microg/mg (103; 549)]. This corresponds to a change of +24 (-37; +517) for the placebo group vs. -10 microg/mg (-36; +16) for the raloxifene group (P = 0.11). In multivariate analysis, raloxifene treatment (P(adjusted) = 0.013), baseline low-density lipoprotein (LDL) cholesterol (P(adjusted) = 0.023) and change in LDL cholesterol (P(adjusted) = 0.008) were related to the absolute change in ACR. Adverse effects were similar in the two groups. These results suggest that raloxifene may limit the progression of albuminuria in post-menopausal women with diabetes; further studies in a larger population are warranted.

Carotid Artery Intima-Media Thickness after Raloxifene Treatment

Raloxifene, a selective estrogen receptor modulator (SERM), decreases total and low-density lipoprotein cholesterol (LDL-C) in postmenopausal women and inhibits increases in intima-media thickness (IMT) in animal models. We tested whether up to 8 years exposure to raloxifene had an effect on subclinical atherosclerosis in the 4-year Multiple Outcomes of Raloxifene Evaluation (MORE) trial and the follow-up study, the 4-year Continuing Outcomes Relevant to Evista (CORE) trial. A subsample of postmenopausal women with osteoporosis, who had completed the MORE and CORE trials and were on average 68 years of age and 19 years postmenopausal at randomization into MORE, participated in this substudy. Within 6 months of cessation of study drug in CORE, right common carotid artery IMT (CIMT) and carotid artery stiffness and arterial compliance were measured at one of two sites (San Diego and San Francisco) using high-resolution B-mode ultrasound. CIMT and arterial stiffness measures were compared between women who had received raloxifene vs. placebo; the primary analysis included only women who were >or=80% drug compliant and had used <or=6 months of lipid-lowering medication during CORE. For the primary analysis dataset (n = 89), there was no significant difference in mean CIMT between the raloxifene and placebo groups (0.83 and 0.81 mm, respectively, p = 0.62). Carotid artery stiffness and compliance were not significantly different between treatment groups (p = 0.33 and 0.59, respectively). These preliminary data suggest that in this self-selected group of elderly post-menopausal women with osteoporosis who were evaluated within 6 months of cessation of study medication, there were no differences between long-term raloxifene treatment and placebo groups in several measures of subclinical atherosclerosis.

Relationships between bone mineral density and breast cancer risk (by Gail model) in postmenopausal women with low bone mass or osteoporosis

An umbrella concept addressing the relationship between chronic kidney disease (CKD) and mineral and bone disorders has been developed in recent years. Given the high prevalence of osteoporosis-related fractures in postmenopausal women with CKD, especially those undergoing chronic hemodialysis, the strategy used in the prevention and management of CKD and its associated osteoporosis in these postmenopausal women has become a topic of substantial debate. This controversy has ongoing relevance because osteoporosis results in a significant economic burden secondary to increased morbidity and mortality. The perfect goal of treatment and prevention includes both bone protection and renal protection, or at least protection of one disease without compromising the other disease. Both CKD and osteoporosis are frequently observed in the same patients, and often have parallel progression in postmenopausal women. Estrogen, the main female hormone during reproductive age, has been reported to have a protective effect on kidney fibrosis in several animal models, and is also considered one of the most effective drugs in the management of postmenopausal women with osteoporosis and prevention of osteoporosis. However, due to the many adverse events associated with the use of estrogen with and without progestin, some of which have contributed to significant morbidity and mortality, drug modification, which has had fewer reported incidences of adverse events without compromising the protective effect on both the kidney and bone, may have an easier road to acceptance. Therapeutic alternatives, such as the selective estrogen receptor modulators (SERMs), have shown the benefits of estrogen on bone, serum lipid levels, and renal protection, without any adverse effects on the breast and endometrium. The Multiple Outcomes of Raloxifene Evaluation trial (MORE) and its extension—Continuing Outcomes Relevant to Evista (CORE), a double-blind, randomized clinical trial encompassing postmenopausal women with osteoporosis, showed promising results in both bone and renal studies. Raloxifene increased bone mineral density (BMD) in the spine and femoral neck and reduced the risk of vertebral fracture. In addition, raloxifene slowed the increase in the rate of serum creatinine and also significantly slowed the decrease in the estimated glomerular filtration rate; of most importance, raloxifene use was associated with significantly fewer kidney-related adverse events. Hemodialyzed women on raloxifene treatment demonstrated increased trabecular BMD, a decrease in bone resorption markers, and a decrease in the low-density lipoprotein-cholesterol value. Thus, raloxifene and, most likely, other SERMs could be better in place of estrogen in the management of postmenopausal women with CKD and its associated osteoporosis, although much evidence should be provided in the advanced-stage CKD, especially in the Stage 5 CKD patients on dialysis.

Exonic, but not intronic polymorphisms of ESR1 gene might influence the hypolipemic effect of raloxifene

Studies have shown that selective modulator of estrogen receptor raloxifene, exerts hypolipemic properties at least partially through estrogen receptor alpha activation. To test the hypothesis that polymorphisms of estrogen receptor alpha are associated with the influence of 6 months raloxifene treatment on serum lipids, two intronic (PvuII and XbaI), and one exonic polymorphism (P325P) were analyzed in 49 postmenopausal women, mean age 62.5 ± 5.7 years. In all subjects, the total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides were determined before and after 6 months of raloxifene treatment. We were unable to find any relationship between estrogen receptor alpha genotype and serum lipids at baseline. At the end of 6 months treatment with raloxifene, the mean decrease of total cholesterol and LDL cholesterol, independently of genotypes, was highly significant, but no influence on HDL and triglycerides concentrations was found. Neither the PvuII nor XbaI ESR1 gene polymorphisms were associated with the magnitude of lipid changes after 6 months treatment, whereas the subjects with non-CC genotype of P325P mutation had significantly lower total cholesterol and LDL cholesterol concentrations, and higher decline of total cholesterol ( p < 0.05). Conclusion Our data suggest that exonic, but not intronic polymorphisms of estrogen receptor alpha gene might intensify the cholesterol lowering effect of raloxifene.

The effect of raloxifene in association with vitamin D on vaginal maturation index and urogenital symptoms in postmenopausal osteoporotic women

In elderly women with osteoporosis, raloxifene treatment with vitamin D supplementation improves vaginal maturation index and vaginal pH.

Apoptosis in raloxifene‐treated postmenopausal women

As raloxifene is a mixed estrogen receptor agonist and antagonist, it exerts different effects on apoptosis in different tissues. In this study, we aimed to evaluate apoptosis in the peripheral lymphocytes of postmenopausal women treated with raloxifene and compare it with untreated control subjects. In this way, we expected to deduce some results about the effect of raloxifene on the immune system and to serve as a guide for future studies on this newly proposed effect of a well-known agent. Twenty osteoporotic postmenopausal women treated with raloxifene for 12 months were included in this study. Another 20 osteoporotic postmenopausal women matched for age and postmenopausal years, but without any medication, were chosen as the control group. Apoptosis was evaluated using a morphological and DNA fragmentation assay, in the peripheral lymphocytes of these women. Our results revealed a decrease in the apoptosis percentages of the patients treated with raloxifene (14.6%) with respect to the control subjects (15.8%), but the difference was not statistically significant (p=0.467). This study indicated that raloxifene treatment had no apoptotic effect on peripheral human lymphocytes compared to controls.

Effect of Raloxifene on Cerebral Vasospasm Following Experimental Subarachnoid Hemorrhage in Rats

The effect of raloxifene on cerebral vasospasm following experimental subarachnoid hemorrhage (SAH) was investigated in a rat model. Seven groups of seven rats underwent no SAH, no treatment; SAH only; SAH plus vehicle; SAH plus 3 days intraperitoneal raloxifene treatment; SAH plus 4 days intraperitoneal raloxifene treatment; SAH plus 3 days intrathecal raloxifene treatment; and SAH plus 4 days intrathecal raloxifene treatment. The basilar artery cross-sectional areas were measured at 72 or 96 hours following SAH. The results showed raloxifene decreased SAH-induced cerebral vasospasm in all treatment groups, and suggested no difference between intraperitoneal and intrathecal application, or between 3 days and 4 days of raloxifene treatment. The present study demonstrates that raloxifene is a potential therapeutic agent against cerebral vasospasm after SAH.

Effect of raloxifene on salivary sex steroid concentrations in premenopausal women

Raloxifene is a selective oestrogen receptor modulator used clinically for the treatment and the prevention of osteoporosis in postmenopausal women. The drug has been evaluated in the Study of Tamoxifen and Raloxifene as an agent to reduce breast cancer incidence in postmenopausal women at high risk. However, about 30% of women who develop breast cancer do so in their premenopausal years. In this pilot study, salivary oestradiol and progesterone were determined throughout the menstrual cycle for a total of 22 subjects, 14 of whom completed pre- and postraloxifene (60 mg daily) salivary collections. The mean concentration of oestradiol during the menstrual cycle when subjects were taking raloxifene was significantly greater (P<0.001) than during baseline cycles. Neither salivary progesterone and cortisol nor menstrual cycle length were affected by raloxifene treatment. These data demonstrate that raloxifene administered to premenopausal women increases the concentration of oestradiol that diffuses into the salivary glands, and which presumably represents the concentration available to other organs as well. The results reflect increases in serum oestradiol reported earlier.

Effects of Raloxifene on Cardiovascular Events and Breast Cancer in Postmenopausal Women

Raloxifene is a nonsteroidal selective estrogen receptor modulator that has favorable effects on markers of cardiovascular risk and has been associated with a reduced risk of coronary heart disease (CHD) in postmenopausal women. Raloxifene also has antiestrogenic effects on the breast and in animals has suppressed the growth of estrogen-stimulated mammary cancers. The Raloxifene Use for The Heart (RUTH) trial was a randomized, double-blind, placebo-controlled study carried out at 177 sites in 26 countries. The 10,101 participants were women aged 55 and older who were at least 12 months postmenopausal and who either had established CHD or were at increased risk. They were assigned to receive either 60 mg raloxifene orally each day or a placebo. The 2 groups were similar in baseline characteristics except for slightly higher cardiovascular risk scores for women assigned to raloxifene. During a median follow up of 5.6 years, no significant differences were found with respect to deaths from coronary causes, nonfatal myocardial infarction, or hospital admission because of an acute coronary syndrome. Women with established CHD and those at increased risk for CHD had similar outcomes. For the primary coronary outcome, the results of as-treated analyses were comparable to those of intention-to-treat analyses. Raloxifene was associated with a decreased incidence of invasive breast cancer; the hazard ratio was 0.56 with a 95% confidence interval of 0.38 to 0.83. The absolute risk reduction for every 1000 women given raloxifene for 1 year was 1.2 cases for both invasive breast cancer and estrogen receptor-positive invasive breast cancer. Among secondary outcomes, the incidence of stroke did not differ significantly between the raloxifene and placebo groups, but fatal strokes were 49% more frequent in raloxifene-treated women. Venous thromboembolic events were 44% more frequent in the raloxifene group. Incidence rates of all breast cancers and of clinical vertebral fractures were lower in the raloxifene group. More than 90% of women in both groups reported adverse events. Rates of discontinuance because of side effects were 22% in the raloxifene group and 20% in the placebo group. Serum levels of low-density lipoprotein cholesterol declined in women given raloxifene but increased in placebo recipients. Levels of high-density lipoprotein cholesterol increased in both groups but more so in women treated with raloxifene. Raloxifene treatment, given for a median of over 5 years to postmenopausal women at increased risk of CHD, did not significantly alter CHD risk in the RUTH study. Its beneficial effects in lowering the risk of invasive breast cancer and vertebral fracture must be weighed against increased risks of fatal stroke and venous thromboembolism.

Treatment With Raloxifene and 17β-estradiol Differentially Modulates Nitric Oxide and Prostanoids in Venous Endothelium and Platelets of Ovariectomized Pigs

Oral treatment with raloxifene, a synthetic estrogen receptor modulator (SERM), or 17beta-estradiol (E2) increases risk for venous thrombosis in women. Acute application of either substance releases endothelium-derived factors from isolated femoral veins but it is not known how their chronic use affects venous functions or the interaction of platelets with veins. This study tested the hypothesis that treatment of ovariectomized animals with oral raloxifene or E2 would increase release of proaggregatory factors from venous endothelium and platelets. Ovariectomized (OVX) pigs were either untreated or treated with oral raloxifene (60 mg/day) or E2 (2 mg/day) for 4 weeks. Plasma concentrations of nitric oxide were comparable in both treatment groups and greater than in OVX pigs. Ratio of plasma thromboxane to prostacyclin was twofold greater in raloxifene compared to E2-treated pigs. In isolated femoral veins, NG-monomethyl-L-arginine (L-NMMA; 10(-4) M) augmented endothelium-dependent relaxations to adenosine diphosphate in veins from E2-treated pigs but inhibited relaxations in veins from raloxifene-treated pigs. Addition of indomethacin (10(-5) M) reversed these effects. Endothelium-dependent relaxations to thrombin were inhibited by L-NMMA only in OVX and raloxifene-treated pigs. Autologous platelets contracted veins in all groups; the magnitude of contractions depended upon the number of platelets and existing tone. Basal release of thromboxane from platelets was greatest in raloxifene compared to OVX or E2-treated pigs. Raloxifene treatment compared to E2 increased production of contractile and proaggregatory prostanoids from venous endothelium and platelets. These differences, if found in humans, may contribute to varying degrees of thrombotic risk with the SERM compared to the natural hormone.

Skeletal pain in postmenopausal women with osteoporosis: prevalence and course during raloxifene treatment in a prospective observational study of 6 months duration

ABSTRACTObjective: To assess the prevalence of skeletal pain in postmenopausal women before the onset of raloxifene treatment and the further course of pain during treatment in a naturalistic setting.Research design and methods: Prospective, uncontrolled, multicentre, 6‐month, observational study in Germany. Clinical, diagnostic and pain data were collected at baseline, 6 weeks and 6 months of raloxifene treatment from 3299 female outpatients with postmenopausal osteoporosis. Physicians assessed the presence or absence of back pain, joint pain and diffuse bone pain at each visit, perceived sleep quality and the use of analgesics. Patients assessed intensity and frequency of pain using a 100 mm visual analogue scale (VAS) and a 5‐point scale (from ‘rarely’ to ‘permanently’), respectively.Results: At baseline, patients had mean (SD) age 67.6 (9.3) years, 89.4% were reported to have reduced bone mineral density, 39.8% had pre-existing fractures and 93.4% had skeletal pain (physician assessment): 85.1% had back pain, 41.8% joint pain and 32.5% diffuse bone pain. Median pain intensity on VAS was 66.0 mm. After 6 months of raloxifene treatment, the frequency and intensity of pain and use of analgesics for skeletal pain decreased consistently by approximately 50%. Pain frequency decreased in 58.2% and increased in 2.3% of patients. The median decrease in pain intensity from baseline to 6 months was 27.0 mm (46%). Patients’ subjective quality of sleep improved: the proportion of patients who were reported to sleep well increased from 21.3% at baseline to 46.7% at 6 months. The decrease in relative pain frequency was greatest with diffuse pain (67.6%) followed by joint pain (36.9%) and back pain (32.5%).Conclusion: Raloxifene treatment in postmenopausal women with osteoporosis was associated with a marked reduction of skeletal pain and analgesic consumption and an improvement in subjective sleep quality. Further investigation in a randomised, placebo-controlled trial is warranted.

A comparative study of the effect of raloxifene and gosereline on uterine leiomyoma volume changes and estrogen receptor, progesterone receptor, bcl-2 and p53 expression immunohistochemically in premenopausal women

Objective To compare the mechanism of action of raloxifene and gosereline induced shrinkage of leiomyomas via estrogen receptor, progesterone receptor, bcl-2 and p53 expression immunohistochemically. Study design Thirty-two premenopausal women affected by uterine leiomyomas were randomized into two equal groups. Group A was treated with gosereline (3.6 mg subcutaneous injection monthly) and group B was treated with raloxifene (60 mg daily per os) for 3 months before undergoing surgery. At entry and at the end of the treatment the leiomyoma volume was measured ultrasonografically and the volume change was calculated. Immunohistochemical detection of estrogen receptor (ER), progesterone receptor (PR), bcl-2 and p53 were performed on leiomyoma tissue samples from group A, group B and the matched-control group. H-scores for ER, PR, bcl-2 and p53 were calculated. The mean volume changes of leiomyomas and immunohistochemical H-score differences of ER, PR, bcl-2 and p53 were compared between groups. Results The leiomyoma volume decreased significantly after treatment in gosereline group from baseline of 65 cm 3 to 35 cm 3, and in raloxifene group from 68 cm 3 to 50 cm 3, p < 0.05. The difference between the before and after treatment leiomyoma volumes between the two treatments was not statistically significant. H-score of ER expression was significantly lower in gosereline group compared to control group (54.4 versus 113.2, p = 0.001), whereas H-score of PR expression was significantly lower with both gosereline and raloxifene groups compared to control group (64.8 for gosereline versus 94.6 for control, 73.6 for raloxifene versus 94.6 for control, p = 0.001). The bcl-2 expression was higher in both gosereline and raloxifene groups compared to control group (173.7 for gosereline versus 94.7 for control, 179.7 for raloxifene versus 94.7 for control, p = 0.001). The p53 expression was only lower with gosereline than the control group (169.4 versus 205.6, p = 0.001), whereas there was no significant change between the raloxifene group and the control group (201.9 versus 205.6) ( p > 0.05). Conclusion Raloxifene was as effective as gosereline in reducing leiomyoma volumes. Decreased PR expression may be a mechanism for tumor growth reduction in raloxifene treatment. In both treatment modalities, the mechanism of shrinkage of leiomyomas could not be increased apoptosis mediated by bcl-2 and p53 expression and should be investigated by further studies.

Effect of long-term treatment with raloxifene on mammary density in postmenopausal women

To evaluate in a group of postmenopausal women the effects of long-term raloxifene treatment on breast density using a digitized analysis of mammograms and on insulinlike growth factor-1 (IGF-1), insulinlike growth factor binding protein-3 (IGFBP-3), and sex hormone-binding globulin (SHBG) plasma levels. Seventy healthy postmenopausal women with normal body weight were enrolled in this study and were divided into two groups based on their bone status, evaluated by dual-energy x-ray at the lumbar spine (L2-4). Fifty women (chronological age 52.4 +/- 4.1 y, menopausal age 42.1 +/- 3.9 y), in whom the L2-4 T score was less than -2.5 SD, were treated with raloxifene HCl 60 mg/day orally for 2 years. The other 20 women (chronological age 53.6 +/- 3.5 y, age at menopause 43.1 +/- 3.6 y), in whom the L2-4 T score ranged between -1 and -2.5 SD, were enrolled as controls. All 70 women received calcium (1 g/d orally) and cholecalciferol (880 UI/d orally) supplementation. Moreover, all women followed a normocaloric and personalized diet. All women had mammography at baseline and after 2 years of therapy. The mammographic images on traditional support (radiography) were acquired by using a film scanner and were then elaborated by means of ad hoc software. Moreover, assessments of IGF-1, IGFBP-3, and SHBG plasma levels were obtained at baseline and after 24 months. After 24 months of therapy, there was a significant variation in the raloxifene-treated group with respect to baseline in the distribution of gray classes of radiographic images. In particular, an attenuation of graphic trace with a reduction of the areas with the lowest and most elevated gray classes was observed. In the control group, no significant variations of graphic traces were observed. Moreover, raloxifene treatment significantly reduced IGF-1 and increased IGFBP-3 and SHBG plasma levels at 24 months. During follow-up, IGF-1, IGFPB-3, and SHBG levels did not change significantly in the control group. Long-term treatment with raloxifene in a population of postmenopausal women is able to reduce breast density. Such an effect could perhaps explain the reduction in the incidence of mammary carcinoma observed in the Multiple Outcomes of Raloxifene Evaluation study probably due to the direct antiestrogenic activity of raloxifene on mammalian tissue and/or its indirect activity increasing SHBG levels or modifying the IGF-1/IGFBP-3 ratio.

Raloxifene Elicits Combined Rapid Vasorelaxation and Long-Term Anti-Inflammatory Actions in Rat Aorta

Previous studies reported the ability of raloxifene to acutely relax arterial and venous vessels, but the underlying mechanisms are controversial. Anti-inflammatory effects of the drug have been reported in nonvascular tissues. Therefore, the aim of this study was to investigate the nature of short- and long-term effects of raloxifene on selected aspects of vascular function in rat aorta. Isometric tension changes in response to raloxifene were recorded in aortic rings from ovariectomized female rats that underwent estrogen replacement, whereas long-term experiments were performed in isolated aortic smooth muscle cells (SMCs). Raloxifene (0.1 pM-0.1 microM) induced acute vasorelaxation through endothelium- and nitric oxide (NO)-dependent, prostanoid-independent mechanisms. The relaxant response to raloxifene was significantly weaker than that to 17beta-estradiol and was sensitive to neither the nonselective estrogen receptor antagonist ICI 182,780 [7,17-[9[(4,4,5,5,5-pentafluoropentyl)sulfinyl]nonyl]estra-1,3,5(10)-triene-3,17-diol] nor a selective estrogen receptor (ER) alpha antagonist. This rapid vasorelaxant effect was retained in aortic rings from rats treated with 0.1 mg/kg, but not 1 mg/kg, lipopolysaccharide, 4 h before sacrifice. In cultured aortic SMCs, raloxifene treatment (1 nM-1 microM) for 24 h reduced inducible NO synthase activation in response to cytokines. This effect was prevented by the selective ERalpha antagonist and was associated with up-regulation of ERalpha protein levels, which dropped markedly upon cytokine stimulation. These findings illustrate the relevance of classic ER-dependent pathways to the vascular anti-inflammatory effects rather than to the nongenomic vasorelaxation induced by raloxifene and may assist in the design of novel ER isoform-selective estrogen-receptor modulators targeted to the vascular system.

Effect of raloxifene on clinical fractures in Asian women with postmenopausal osteoporosis

Osteoporosis is becoming a major public health problem in Asian countries, with a rapid increase in osteoporotic fractures projected as urbanization increases, particularly in China. The purpose of this post hoc analysis was to assess the effects of 12 months of treatment with raloxifene on the incidence of clinical fractures in postmenopausal Asian women, compared to a placebo, by combining two independently designed studies (one Japanese study and one Chinese study). A total of 488 women, 284 in Japan and 204 in China were included in the analysis. Baseline characteristics (mean +/- SD) for the Japanese and Chinese women were: age, 64.8 +/- 6.3 years and 65.3 +/- 6.0 years; body mass index, 21.8 +/- 2.8 kg/m(2) and 23.0 +/- 2.9 kg/m(2); and prevalent vertebral fractures, 26.4% and 13.7%, respectively. In both studies, the clinical vertebral and nonvertebral fractures were confirmed by radiographs or clinical reports at a central research facility. From the two combined studies, the incidence of new clinical vertebral fractures was significantly lower in the raloxifene 60 mg/day (RLX60) group (0 out of 194, P = 0.01) and in the pooled raloxifene group (those taking 60 mg/day and those taking 120 mg/day) (0 out of 289, P = 0.002), compared with the placebo group (7 out of 199, 3.5%). The pooled raloxifene group, as well as the RLX60 group, also had a significantly lower incidence of any new clinical fracture (P = 0.001 and P = 0.01, respectively) compared to the placebo group. In conclusion, raloxifene treatment at 60 mg/day for 1 year resulted in a significant reduction in the risk of new clinical vertebral fractures and any new clinical fracture in postmenopausal Asian women with osteoporosis.

The potential antioxidant effect of raloxifene treatment: a study on heart, liver and brain cortex of ovariectomized female rats

The antioxidant activity of some compounds buffer the free radicals generated either endogenously or exogenously, thus decreasing the potential damage mediated by oxidation. Recent studies documented that raloxifene has antioxidant properties in vitro. However, there are limited animal studies available to show raloxifene's antioxidant properties. We aimed to investigate the effects of raloxifene on antioxidant enzymes such as SOD, CAT and GPX, TrxR and the levels of GSH and MDA in heart, liver and brain cortex of ovariectomized female rats. Female Sprague Dawley rats weighing 300-350 g (n=24) were divided into three groups: (I) Eight non-ovariectomized rats were used as naive controls without any treatment (non-ovariectomized group, n=8). Five weeks after ovariectomy, (II) Ovariectomized placebo group (n=8) was given physiological saline, and (III) Raloxifene group (n=8) was given raloxifene 1 mg/kg sc. daily for 12 days. Ovariectomy induced significant increases on SOD, GPX, CAT activity and MDA levels in brain, heart and liver tissues compared to non-ovariectomized rats ( p<0.05). Raloxifene treatment led to decreased levels of SOD activity in heart, GPX activity in brain and CAT activity in liver tissue when compared to ovariectomized group ( p<0.05) but there was no change in activity of TrxR in all groups. The levels of MDA in brain, heart and liver tissues increased in ovariectomized group when compared to non-ovariectomized rats ( p<0.05). Raloxifene had a significant attenuating effect on the levels of MDA in brain and heart tissues. Our results also indicate that the levels of GSH in brain, heart and liver tissue decreased when compared to non-ovariectomized rats. Raloxifene treatment was observed to significantly increase the levels of GSH in brain and heart tissues ( p<0.05). However, there were insignificant differences for the GSH levels in liver tissues of ovariectomized placebo or raloxifene groups. In conclusion, our results demonstrate that raloxifene may be more effective against oxidative stress in heart and brain than in liver tissue.

A Canadian Observational Study of the Optimal Method of Transition From Postmenopausal Hormone Therapy to Raloxifene

ObjectiveTo determine the optimal method of transition from postmenopausal hormone therapy (HT) to raloxifene (RLX) therapy in order to minimize hot flashes and night sweats. MethodsPostmenopausal women in Canada who had discontinued HT (estrogen with or without progestogen) in the preceding nine months and who were starting RLX were followed for approximately nine months in this observational study. The method of transition from HT to RLX therapy (method and duration of tapering HT, duration of washout) and the frequency and severity of hot flashes during the transition and RLX treatment periods were recorded. ResultsThere were 373 women who participated in this study. Most women (86.3%) had a washout period between HT and RLX, and 55.2% had tapered their HT in some fashion. After beginning RLX, women who had had a washout duration of more than one week were found to be more likely to have an improvement in the severity of hot flashes (odds ratio [OR]=6.3), and in the frequency of hot flashes (OR=4.6), than women with a shorter washout or no washout period at all. The method of tapering of HT did not seem to affect either the severity or the frequency of hot flashes once on RLX. Women who had undergone a tapering period of more than one week’s duration were more likely (OR=2.6) to experience an improvement in the frequency (but not the severity) of hot flashes on RLX. ConclusionWomen who had a washout period following HT had better amelioration of hot flashes on RLX therapy.