Carnosic acid suppresses the production of amyloid-ß 1-42 by inducing the metalloprotease gene TACE/ADAM17 in SH-SY5Y human neuroblastoma cells.

A hallmark of Alzheimer's disease (AD) is the aggressive appearance of plaques of amyloid beta (Aß) peptides, which result from the sequential cleavage of amyloid precursor protein (APP) by the ß- and γ-secretases. Aß production is evaded by alternate cleavage of APP by the α- and γ-secretases. Carnosic acid (CA) has been proven to activate the transcription factor Nrf2, a main regulator of the antioxidant response. We investigated the effects of CA on the production of Aß 1-42 peptide (Aß42) and on the expressions of the related genes in SH-SY5Y human neuroblastoma cells. The treatment of cells with CA suppressed Aß42 secretion (61% suppression at 30µM). CA treatment enhanced the mRNA expressions of an α-secretase TACE (tumor necrosis factor-α-converting enzyme, also called a disintegrin and metalloproteinase-17, ADAM17) significantly and another α-secretase ADAM10 marginally; however, the ß-secretase BACE1 (ß-site APP-cleaving enzyme-1) was not increased by CA. Knockdown of TACE by siRNA reduced soluble-APPα secretion enhanced by CA and partially recovered the CA-suppressed Aß42 secretion. These results suggest that CA reduces Aß42 production by activating TACE without promoting BACE1 in human neuroblastoma cells. The use of CA may have a potential in the prevention of Aß-mediated diseases, particularly AD.

Nrf2 regulates NGF mRNA induction by carnosic acid in T98G glioblastoma cells and normal human astrocytes.

Nerve growth factor (NGF) is a neurotrophic factor that plays an important role in neuronal cell development and survival. Carnosic acid (CA), a hydrophobic constituent of the herb rosemary, induces NGF production in human T98G glioblastoma cells, but the mechanism through which it works remains unknown. In the present study, we found a redox-sensitive transcription factor, Nrf2, which coordinates the expression of cytoprotective phase 2 genes, also participates in CA-inducible NGF expression. In T98G cells, CA caused NGF gene induction in a dose- and time-dependent manner without altering NGF mRNA stability. Simultaneously, CA increased Nrf2 nuclear accumulation and activated expression of prototypical Nrf2 target genes such as haem oxygenase 1 (HO-1) and thioredoxin reductase 1 (TXNRD1). Knockdown of endogenous Nrf2 by Nrf2-specific siRNA significantly reduced constitutive and CA-inducible NGF gene expression. In addition, NGF gene expression was enhanced by knockdown of Keap1, an Nrf2 inhibitor, in the absence of CA. Furthermore, CA induced NGF expression in normal human astrocytes in an Nrf2-dependent manner. These results highlight a role of Nrf2 in NGF gene expression in astroglial cells.

Edaravone and carnosic acid synergistically enhance the expression of nerve growth factor in human astrocytes under hypoxia/reoxygenation.

Edaravone is a brain-penetrant free radical scavenger that is known to ameliorate postischemic neuronal dysfunction. The transcription factor Nrf2 plays an important role in the coordinated expression of stress-inducible genes. Here we examined the effects of edaravone and carnosic acid (CA), an Nrf2-inducer, on the expression of nerve growth factor (NGF) in human astrocytes exposed to hypoxia/reoxygenation. Cultured astrocytes were exposed to hypoxia for up to 4.5 h and then treated with edaravone and/or CA under normoxia (reoxygenation) for up to 72 h. Edaravone (∼1 mM) and CA (∼50 µM) treatment synergistically enhanced NGF expression. Nrf2 knockdown by siRNA and the inhibition of JNK (c-Jun N-terminal kinase) by SP600125 decreased both CA-induced NGF expression and Nrf2 nuclear accumulation and suppressed their synergistic effect on NGF expression. In contrast, the MEK (mitogen-activated protein kinase/extracellular signal-regulated kinase kinase) inhibitor U0126 suppressed the synergism without inhibiting CA-induced NGF expression. These results suggest that the synergistic effects of CA and edaravone depend, at least partially, on JNK-dependent Nrf2 accumulation (induced by CA) and on MEK-dependent pathways (induced by edaravone). We conclude that the use of edaravone and CA in combination may have therapeutic potential in the treatment of brain damage, particularly ischemia/reperfusion injury.

The prevention of hip fracture with risedronate and ergocalciferol plus calcium supplementation in elderly women with Alzheimer disease: a randomized controlled trial.

BACKGROUND: A high incidence of fractures, particularly of the hip, represents an important problem in patients with Alzheimer disease (AD), who are prone to falls and have osteoporosis. We previously found that deficiency of 25-hydroxyvitamin D and compensatory hyperparathyroidism cause reduced bone mineral density in female patients with AD. We address the possibility that treatment with risedronate sodium and ergocalciferol plus calcium supplementation may reduce the incidence of nonvertebral fractures in elderly women with AD. METHODS: A total of 500 elderly women with AD were randomly assigned to daily treatment with 2.5 mg of risedronate sodium or a placebo, combined with 1000 IU of ergocalciferol and 1200 mg of elementary calcium, and followed up for 18 months. RESULTS: At baseline, patients of both groups showed 25-hydroxyvitamin D deficiency with compensatory hyperparathyroidism. During the study period, bone mineral density in the risedronate group increased by 4.1% and decreased by 0.9% in the control group. Vertebral fractures occurred in 29 patients (24 hip fractures) in the control group and 8 patients (5 hip fractures) in the risedronate group. The relative risk in the risedronate group compared with the control group was 0.28 (95% confidence interval, 0.13-0.59). CONCLUSIONS: Elderly patients with AD hypovitaminosis D are at increased risk for hip fracture. Treatment with risedronate and ergocalciferol may be safe and effective in reducing the risk of a fracture in elderly patients with AD.

Low-dose vitamin D prevents muscular atrophy and reduces falls and hip fractures in women after stroke: a randomized controlled trial.

OBJECTIVE: Vitamin D supplementation is suggested to reduce the risk of falls among ambulatory or institutionalized elderly subjects. The present study was undertaken to address the reduced risk of falls and hip fractures in patients with long-standing stroke by vitamin D supplementation. METHODS: Ninety-six elderly women with poststroke hemiplegia were followed for two years. Patients were randomly assigned to one of the two groups, and 48 patients received 1,000 IU ergocalciferol daily, and the remaining 48 received placebo. The number of falls per person and incidence of hip fractures were compared between the two groups. Strength and tissue ATPase of skeletal muscles on the nonparetic side were assessed before and after the study. RESULTS: At baseline, serum 25-hydroxyvitamin D levels were in the deficient range (<10 ng/ml) in all patients; and vitamin D treatment enhanced serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels. Vitamin D treatment accounted for a 59% reduction in falls (95% CI, 28-81%; p = 0.003). There were increases in the relative number and size of type II muscle fibers and improved muscle strength in the vitamin D-treated group. Hip fractures occurred in 4 of 48 placebo group and 0 in 48 vitamin D2 group during the 2-year study period (log-rank, p = 0.049). CONCLUSION: Vitamin D may increase muscle strength by improving atrophy of type II muscle fibers, which may lead to decreased falls and hip fractures.

Abnormal bone and calcium metabolism in immobilized Parkinson's disease patients.

To elucidate the influence of immobilization-induced hypercalcemia on bone metabolism in Parkinson's disease (PD), we measured serum biochemical indexes and bone mineral density (BMD) in the second metacarpals of 142 elderly PD patients and 99 age-matched healthy controls. Serum concentrations of 25-hydroxyvitamin D (25-OHD), 1,25-dihydroxyvitamin D (1,25-[OH](2)D), ionized calcium, intact parathyroid hormone (PTH), and intact bone Gla protein (BGP) were measured. Urinary deoxypyridinoline (D-Pyr) was also measured. Increased serum calcium levels (mean, 1.27 mmol/L) were observed in PD patients, and the levels correlated negatively with the Unified Parkinson's Disease Rating Scale III (UPDRS III), indicating the presence of immobilization-induced bone resorption with resultant hypercalcemia. Decreased serum concentrations of 1,25-[OH](2)D (mean, 88.7 pmol/L) and 25-OHD (mean, 29.7 nmol/L) were noted. Serum PTH was decreased (mean, 25.2 ng/L). Serum BGP was decreased while urinary D-Pyr concentration elevated. A negative correlation was observed between 1,25-[OH](2)D levels and serum calcium or UPDRS III (P < 0.0001). In disabled PD patients, immobilization-induced hypercalcemia may inhibit secretion of PTH, which in turn suppresses 1,25-[OH](2)D production. 25-OHD insufficiency may also contribute to decreased 1,25-[OH](2)D. These abnormalities may be corrected by the suppression of bone resorption with bisphoshonate, and supplementations of calcium and vitamin D should be avoided in these patients.

Amelioration of osteoporosis and hypovitaminosis D by sunlight exposure in hospitalized, elderly women with Alzheimer's disease: a randomized controlled trial.

UNLABELLED: In a random and prospective study, Alzheimer's disease (AD) patients were assigned to regular sunlight exposure (n = 132) or sunlight deprivation (n = 132) and followed for 1 year. Serum 25-OHD level increased by 2.2-fold in the sunlight-exposed group. Eleven patients sustained fractures in the sunlight-deprived group, and three fractures occurred among the sunlight-exposed group (p = 0.0362; odds ratio = 3.7). INTRODUCTION: A high incidence of fractures, particularly of the hip, represents an important problem in patients with Alzheimer's disease (AD), who are prone to falls and have osteoporosis. We previously showed that 25-hydroxyvitamin D (25-OHD) deficiency caused by sunlight deprivation with compensatory hyperparathyroidism causes reduced BMD in elderly women with AD. This study was undertaken to address the possibility that sunlight exposure with calcium supplementation may maintain BMD and reduce the incidence of nonvertebral fractures in elderly women with AD. MATERIALS AND METHODS: In a random and prospective study, AD patients were assigned to regular sunlight exposure (n = 132) or sunlight deprivation (n = 132) and followed for 1 year. BMD of the second metacarpal bone was measured using a computed X-ray densitometer (CXD). The CXD method measures BMD and cortical thickness at the middle of the second metacarpal bone on a radiogram of the hand and an aluminum step wedge as a standard (20 steps; 1 mm/step). Incidence of nonvertebral fractures in the two patient groups during the 1-year follow-up period was assessed. RESULTS AND CONCLUSION: At baseline, average hospitalization period was 1.7 years in both groups, and activity of daily living (ADL) was decreased. Patients of both groups showed vitamin D deficiency caused by sunlight deprivation and decreased dietary intake of vitamin D with compensatory hyperparathyroidism. The exposed group patients were exposed to sunlight (3615 minutes/year). BMD increased by 2.7% in the sunlight-exposed group and decreased by 5.6% in the sunlight-deprived group (p < 0.0001). Serum 25-OHD level increased from 24.0 to 52.2 nM in the sunlight-exposed group. Eleven patients sustained fractures in the sunlight-deprived group, and three fractures occurred among the sunlight-exposed group (p = 0.0362; odds ratio = 3.7). Sunlight exposure can increase the BMD of vitamin D-deficient bone by increasing 25-OHD concentration and lead to the prevention of nonvertebral fractures.

Effect of folate and mecobalamin on hip fractures in patients with stroke: a randomized controlled trial.

CONTEXT: Stroke increases the risk of subsequent hip fracture by 2 to 4 times. Hyperhomocysteinemia is a risk factor for both ischemic stroke and osteoporotic fractures in elderly men and women. Treatment with folate and mecobalamin (vitamin B12) may improve hyperhomocysteinemia. OBJECTIVE: To investigate whether treatment with folate and vitamin B12 reduces the incidence of hip fractures in patients with hemiplegia following stroke. DESIGN, SETTING, AND PATIENTS: A double-blind, randomized controlled study of 628 consecutive patients aged 65 years or older with residual hemiplegia at least 1 year following first ischemic stroke, who were recruited from a single Japanese hospital from April 1, 2000, to May 31, 2001. Patients were assigned to daily oral treatment with 5 mg of folate and 1500 microg of mecobalamin, or double placebo; 559 completed the 2-year follow-up. MAIN OUTCOME MEASURE: Incidence of hip fractures in the 2 patient groups during the 2-year follow-up. RESULTS: At baseline, patients in both groups had high levels of plasma homocysteine and low levels of serum cobalamin and serum folate. After 2 years, plasma homocysteine levels decreased by 38% in the treatment group and increased by 31% in the placebo group (P<.001). The number of hip fractures per 1000 patient-years was 10 and 43 for the treatment and placebo groups, respectively (P<.001). The adjusted relative risk, absolute risk reduction, and the number needed to treat for hip fractures in the treatment vs placebo groups were 0.20 (95% confidence interval [CI], 0.08-0.50), 7.1% (95% CI, 3.6%-10.8%), and 14 (95% CI, 9-28), respectively. No significant adverse effects were reported. CONCLUSION: In this Japanese population with a high baseline fracture risk, combined treatment with folate and vitamin B12 is safe and effective in reducing the risk of a hip fracture in elderly patients following stroke.

RETRACTED: Menatetrenone and vitamin D2 with calcium supplements prevent nonvertebral fracture in elderly women with Alzheimer's disease.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Corresponding Author, Yoshihiro Sato, and the co-authors have been informed. Dr. Sato wishes to retract this article on the grounds that it contains fabricated clinical trial data, which he was responsible for producing. In addition, Dr. Sato claims he listed all of the named co-authors without their consent. The co-authors were therefore unaware of the presence of fabricated data in this publication and their participation in the publication. This retraction was initiated by Dr. Sato, and the Editor-in-Chief of Bone was informed by the author directly.

Risk factors for hip fracture among elderly patients with Alzheimer's disease.

Incidence of hip fracture among patients with Alzheimer's disease (AD), especially in elderly patients, is high. To analyze risk factors of hip fracture, we prospectively studied a cohort of elderly female patients with AD. Subjects studied were 225 female patients with AD, and the average age was 76 years old. At baseline, we recorded body mass index (BMI), a score of Mini-Mental State Examination (MMSE) and bone mineral density (BMD), and measured serum concentrations of ionized calcium, intact parathyroid hormone (PTH), pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), intact bone Gla protein (BGP), 25-hydroxyvitamin (25-OHD) and 1, 25-dihydroxyvitamin D (1, 25-[OH]2D). The patients were followed for 2 years. During the 2-year study, hip fractures occurred in 29 patients. We compared baseline variables between the 29 patients with and 176 patients without hip fracture. AD patients with lower BMD, low concentrations of serum ionized calcium and 25-OHD (mean 3.0 ng/ml) with compensatory hyperparathyroidism were found to have an increased risk of hip fracture. Also, concentrations of serum ICTP and BGP were higher in the fracture group than in the nonfracture group. Elderly female AD patients with low BMD and serum 25-OHD concentrations <5 ng/ml with secondary hyperparathyroidism have a high risk of hip fracture, and the risk may be reduced by vitamin D supplementation.

Amelioration of osteoporosis and hypovitaminosis D by sunlight exposure in stroke patients.

BACKGROUND: The authors' previous investigations have disclosed low serum 25-hydroxyvitamin D (25-OHD) concentrations in 45 patients during long-term hospitalization following stroke (mean 5.9 ng/mL). This 25-OHD deficiency resulted from sunlight deprivation. OBJECTIVE: To evaluate the efficacy of sunlight exposure in increasing serum 25-OHD, in reducing the severity of osteoporosis in bone mineral density (BMD), and in decreasing the risk of hip fractures in chronically hospitalized, disabled stroke patients. METHODS: In a 12-month randomized and prospective study of stroke patients, 129 received regular sunlight exposure for 12 months, and the remaining 129 (sunlight-deprived) did not. RESULTS: At baseline, patients of both groups showed vitamin D deficiency. BMD increased by 3.1% in the sunlight-exposed group and decreased by 3.3% in the sunlight-deprived group (p = 0.0001). 25-OHD level increased by fourfold in the sunlight-exposed group. Six patients sustained hip fractures on the hemiplegic side in the sunlight-deprived group, and one hip fracture occurred among the sunlight-exposed group (p = 0421; odds ratio = 6.1). CONCLUSION: Sunlight exposure can increase the BMD of vitamin D-deficient bone by increasing 25-OHD concentration.

Hyperhomocysteinemia in Japanese patients with convalescent stage ischemic stroke: effect of combined therapy with folic acid and mecobalamine.

Hyperhomocysteinemia is considered to be a risk factor for vascular diseases including ischemic stroke. It has been shown that plasma homocysteine level can be lowered by folic acid supplementation. Vitamin B(12) may be also beneficial when included in the supplement regimen with folic acid. We have examined in Japanese patients with ischemic stroke the homocysteine-lowering potential of a combination therapy with folic acid and vitamin B(12). Patients with ischemic stroke were randomized into three groups and each group received vitamin B(12) (1500 microg/day, n = 63), folic acid (5 mg/day, n = 64), or both vitamin B(12) and folic acid (n = 64) for 8 weeks. Plasma levels of homocysteine and these vitamins were followed. Significant reduction in plasma homocysteine was observed in all three groups, and the combination therapy yielded the most remarkable result, i.e., plasma total homocysteine was reduced by 38.5% and this was significantly larger than the reduction in other two groups (22.4% and 10.9% in the groups received folic acid and vitamin B(12), respectively). Vitamin B(12) synergizes with folic acid in reducing plasma homocysteine in Japanese patients with ischemic stroke and the combined therapy may be particularly effective in the secondary prevention.