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1.
Int J Med Sci ; 20(13): 1711-1721, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37928881

RESUMO

Background: Menopause is accompanied by increased oxidative stress, partly contributing to weight gain and bone marrow adiposity. Traditional Chinese medication, E'Jiao, has been demonstrated to reduce excessive bone remodelling during oestrogen deprivation, but its effects on body composition and bone marrow adiposity during menopause remain elusive. Objective: To determine the effects of E'Jiao on body composition, bone marrow adiposity and skeletal redox status in ovariectomised (OVX) rats. Methods: Seven groups of three-month-old female Sprague Dawley rats were established (n=6/group): baseline, sham, OVX control, OVX-treated with low, medium or high-dose E'Jiao (0.26, 0.53, 1.06 g/kg, p.o.) or calcium carbonate (1% in tap water, ad libitum). The supplementation was terminated after 8 weeks. Whole-body composition analysis was performed monthly using dual-energy X-ray absorptiometry. Analysis of bone-marrow adipocyte numbers and skeletal antioxidant activities were performed on the femur. Results: Increased total mass, lean mass, and bone marrow adipocyte number were observed in the OVX control versus the sham group. Low-dose E'Jiao supplementation counteracted these changes. Besides, E'Jiao at all doses increased skeletal catalase and superoxide dismutase activities but lowered glutathione levels in the OVX rats. Skeletal malondialdehyde level was not affected by ovariectomy but was lowered with E'Jiao supplementation. However, peroxisome proliferator-activated receptor gamma protein expression was not affected by ovariectomy or any treatment. Conclusion: E'Jiao, especially at the low dose, prevented body composition changes and bone marrow adiposity due to ovariectomy. These changes could be mediated by the antioxidant actions of E'Jiao. It has the potential to be used among postmenopausal women to avoid adiposity.


Assuntos
Adiposidade , Medula Óssea , Humanos , Ratos , Feminino , Animais , Lactente , Ratos Sprague-Dawley , Antioxidantes/farmacologia , Obesidade , Oxirredução , Ovariectomia/efeitos adversos , Densidade Óssea
2.
Int J Mol Sci ; 24(8)2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37108321

RESUMO

Bone grafting is commonly used as a treatment to repair bone defects. However, its use is challenged by the presence of medical conditions that weaken the bone, like osteoporosis. Calcium phosphate cement (CPC) is used to restore bone defects, and it is commonly available as a bioabsorbable cement paste. However, its use in clinical settings is limited by inadequate mechanical strength, inferior anti-washout characteristics, and poor osteogenic activity. There have been attempts to overcome these shortcomings by adding various natural or synthetic materials as enhancers to CPC. This review summarises the current evidence on the physical, mechanical, and biological properties of CPC after doping with synthetic materials. The incorporation of CPC with polymers, biomimetic materials, chemical elements/compounds, and combination with two or more synthetic materials showed improvement in biocompatibility, bioactivity, anti-washout properties, and mechanical strength. However, the mechanical property of CPC doped with trimethyl chitosan or strontium was decreased. In conclusion, doping of synthetic materials enhances the osteogenic features of pure CPC. The positive findings from in vitro and in vivo studies await further validation on the efficacy of these reinforced CPC composites in clinical settings.


Assuntos
Osso e Ossos , Osteogênese , Teste de Materiais , Polímeros , Fosfatos de Cálcio/farmacologia , Fosfatos de Cálcio/química , Cimentos Ósseos/farmacologia , Cimentos Ósseos/química
3.
Molecules ; 28(6)2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36985762

RESUMO

Metabolic syndrome (MetS) is composed of central obesity, hyperglycemia, dyslipidemia and hypertension that increase an individual's tendency to develop type 2 diabetes mellitus and cardiovascular diseases. Kelulut honey (KH) produced by stingless bee species has a rich phenolic profile. Recent studies have demonstrated that KH could suppress components of MetS, but its mechanisms of action are unknown. A total of 18 male Wistar rats were randomly divided into control rats (C group) (n = 6), MetS rats fed with a high carbohydrate high fat (HCHF) diet (HCHF group) (n = 6), and MetS rats fed with HCHF diet and treated with KH (HCHF + KH group) (n = 6). The HCHF + KH group received 1.0 g/kg/day KH via oral gavage from week 9 to 16 after HCHF diet initiation. Compared to the C group, the MetS group experienced a significant increase in body weight, body mass index, systolic (SBP) and diastolic blood pressure (DBP), serum triglyceride (TG) and leptin, as well as the area and perimeter of adipocyte cells at the end of the study. The MetS group also experienced a significant decrease in serum HDL levels versus the C group. KH supplementation reversed the changes in serum TG, HDL, leptin, adiponectin and corticosterone levels, SBP, DBP, as well as adipose tissue 11ß-hydroxysteroid dehydrogenase type 1 (11ßHSD1) level, area and perimeter at the end of the study. In addition, histological observations also showed that KH administration reduced fat deposition within hepatocytes, and prevented deterioration of pancreatic islet and renal glomerulus. In conclusion, KH is effective in preventing MetS by suppressing leptin, corticosterone and 11ßHSD1 levels while elevating adiponectin levels.


Assuntos
Diabetes Mellitus Tipo 2 , Mel , Síndrome Metabólica , Ratos , Masculino , Abelhas , Animais , Dieta Hiperlipídica/efeitos adversos , Ratos Wistar , Leptina , Adiponectina , Corticosterona , Carboidratos da Dieta , Tecido Adiposo/metabolismo , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/etiologia , Síndrome Metabólica/metabolismo
4.
Int J Med Sci ; 19(11): 1648-1659, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36237992

RESUMO

Postmenopausal osteoporosis transpires due to excessive osteoclastic bone resorption and insufficient osteoblastic bone formation in the presence of oestrogen insufficiency. Kang Shuai Lao Pian (KSLP) is a red ginseng-based traditional Chinese medicine known for its anti-ageing properties. However, studies on its effect on bone loss are lacking. Thus, the current study examined the skeletal protective effects of KSLP in an ovariectomised rodent bone loss model. Three-month-old female Sprague Dawley rats (n=42) were randomised into baseline, sham and ovariectomised (OVX) groups. The OVX rats were supplemented with low- (KSLP-L; 0.15 g/kg), medium- (KSLP-M; 0.30 g/kg), high-dose KSLP (KSLP-H; 0.45 g/kg) or calcium carbonate (1% w/v). The daily supplementation of KSLP was performed via oral gavage for eight weeks. Gavage stress was stimulated in the ovariectomised control with distilled water. The rats were euthanised at the end of the study. Whole-body and femoral bone mineral content and density scans were performed at baseline and every four weeks. Blood samples were obtained for the determination of bone remodelling markers. Histomorphometry and biomechanical strength testing were performed on femurs and tibias. High bone remodelling typically due to oestrogen deficiency, indicated by the elevated bone formation and resorption markers, osteoclast surface, single-labelled surface and mineralising surface/bone surface ratio, was observed in the untreated OVX rats. Whole-body BMD adjusted to body weight and Young's modulus decreased significantly in the untreated OVX rats. High-dose KSLP supplementation counteracted these degenerative changes. In conclusion, KSLP improves bone health by normalising bone remodelling, thereby preventing bone loss and decreased bone strength caused by oestrogen deficiency. Its anti-osteoporosis effects should be validated in patients with postmenopausal osteoporosis.


Assuntos
Reabsorção Óssea , Osteoporose Pós-Menopausa , Animais , Densidade Óssea , Carbonato de Cálcio/farmacologia , China , Estrogênios , Feminino , Humanos , Laos , Osteoporose Pós-Menopausa/etiologia , Ovariectomia/efeitos adversos , Ratos , Ratos Sprague-Dawley , Água/farmacologia
5.
Ann Hum Biol ; 49(7-8): 299-304, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36373795

RESUMO

BACKGROUND: Body mass index (BMI) is a widely used surrogate tool to screen for obesity/adiposity, but it cannot differentiate between lean and fat mass. Thus, alternative tools to detect excess adiposity should be identified. AIM: This study aimed to compare the performance of BMI, waist circumference (WC) and waist-to-height ratio (WtHR) in predicting Malaysians with excess body fat defined by dual-energy X-ray absorptiometry (DXA). SUBJECTS AND METHODS: A total of 399 men and women aged ≥40 years were recruited from Klang Valley, Malaysia. The body composition of the subjects, including body fat percentage, was measured by DXA. The weight, height, WC and WHtR of the subjects were also determined. RESULTS: BMI [sensitivity = 55.7%, specificity = 86.1%, area under curve (AUC) = 0.709] and WC (sensitivity = 62.7%, specificity = 90.3%, AUC = 0.765) performed moderately in predicting excess adiposity. Their performance and sensitivity improved with lower cut-off values. The performance of WHtR (sensitivity = 96.6%, specificity = 36.1, AUC = 0.664) was optimal at the standard cut-off value and no modification was required. CONCLUSION: The performance of WC in identifying excess adiposity was greater than BMI and WHtR based on AUC values. Modification of cut-off values for BMI and WC could improve their performance and should be considered by healthcare providers in screening individuals with excess adiposity.


Assuntos
Adiposidade , Obesidade , Masculino , Humanos , Feminino , Índice de Massa Corporal , Circunferência da Cintura , Obesidade/diagnóstico , Composição Corporal , Razão Cintura-Estatura
6.
Molecules ; 27(21)2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36364068

RESUMO

Stingless bee honey (SLBH) has a high moisture content, making it more prone to fermentation and leading to honey spoilage. Dehydration of SLBH after harvest is needed to reduce the moisture content. This review compiles the available data on the dehydration methods for SLBH and their effect on its physicochemical properties. This review discovered the dehydration process of vacuum drying at 60 °C and 5% moisture setting, freeze-drying at −54 °C and 5% moisture setting for 24 h, and using a food dehydrator at 55 °C for 18 h could extract >80% water content in SLBH. As a result, these methods could decrease moisture content to <17% and water activity to <0.6. These will prevent the fermentation process and microorganism growth. The hydroxymethylfurfural (HMF) contents remain within the permissible standard of <40 mg/kg. The total phenolic content increased after dehydration by these methods. Therefore, dehydration of SLBH is recommended to increase its benefits.


Assuntos
Mel , Abelhas , Animais , Mel/análise , Desidratação , Fenóis , Antioxidantes/análise , Água
7.
Molecules ; 27(18)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36144598

RESUMO

Glucocorticoid-induced osteogenic dysfunction is the main pathologyical mechanism underlying the development of glucocorticoid-induced osteoporosis. Glucocorticoids promote adipogenic differentiation and osteoblast apoptosis through various pathways. Various ongoing studies are exploring the potential of natural products in preventing glucocorticoid-induced osteoporosis. Preclinical studies have consistently shown the bone protective effects of tocotrienol through its antioxidant and anabolic effects. This review aims to summarise the potential mechanisms of tocotrienol in preventing glucocorticoid-induced osteoporosis based on existing in vivo and in vitro evidence. The current literature showed that tocotrienol prevents oxidative damage on osteoblasts exposed to high levels of glucocorticoids. Tocotrienol reduces lipid peroxidation and increases oxidative stress enzyme activities. The reduction in oxidative stress protects the osteoblasts and preserves the bone microstructure and biomechanical strength of glucocorticoid-treated animals. In other animal models, tocotrienol has been shown to activate the Wnt/ß-catenin pathway and lower the RANKL/OPG ratio, which are the targets of glucocorticoids. In conclusion, tocotrienol enhances osteogenic differentiation and bone formation in glucocorticoid-treated osteoblasts while improving structural integrity in glucocorticoid-treated rats. This is achieved by preventing oxidative stress and osteoblast apoptosis. However, these preclinical results should be validated in a randomised controlled trial.


Assuntos
Anabolizantes , Produtos Biológicos , Osteoporose , Tocotrienóis , Anabolizantes/farmacologia , Animais , Antioxidantes/metabolismo , Produtos Biológicos/farmacologia , Glucocorticoides/efeitos adversos , Osteoblastos , Osteogênese , Osteoporose/induzido quimicamente , Osteoporose/tratamento farmacológico , Osteoporose/metabolismo , Ratos , Tocotrienóis/química , Tocotrienóis/farmacologia , beta Catenina/metabolismo
8.
Int J Med Sci ; 18(3): 604-614, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33437195

RESUMO

Chronic psychological stress affects many body systems, including the skeleton, through various mechanisms. This review aims to provide an overview of the factors mediating the relationship between psychological stress and bone health. These factors can be divided into physiological and behavioural changes induced by psychological stress. The physiological factors involve endocrinological changes, such as increased glucocorticoids, prolactin, leptin and parathyroid hormone levels and reduced gonadal hormones. Low-grade inflammation and hyperactivation of the sympathetic nervous system during psychological stress are also physiological changes detrimental to bone health. The behavioural changes during mental stress, such as altered dietary pattern, cigarette smoking, alcoholism and physical inactivity, also threaten the skeletal system. Psychological stress may be partly responsible for epigenetic regulation of skeletal development. It may also mediate the relationship between socioeconomic status and bone health. However, more direct evidence is required to prove these hypotheses. In conclusion, chronic psychological stress should be recognised as a risk factor of osteoporosis and stress-coping methods should be incorporated as part of the comprehensive osteoporosis-preventing strategy.


Assuntos
Densidade Óssea/fisiologia , Desenvolvimento Ósseo/fisiologia , Osteoporose/etiologia , Estresse Psicológico/complicações , Adaptação Psicológica/fisiologia , Alcoolismo/epidemiologia , Alcoolismo/psicologia , Animais , Osso e Ossos/metabolismo , Fumar Cigarros/epidemiologia , Fumar Cigarros/psicologia , Epigênese Genética/fisiologia , Comportamento Alimentar/psicologia , Glucocorticoides/metabolismo , Humanos , Leptina/metabolismo , Modelos Animais , Osteoporose/epidemiologia , Osteoporose/metabolismo , Osteoporose/fisiopatologia , Hormônio Paratireóideo/metabolismo , Prolactina/metabolismo , Fatores de Risco , Estresse Psicológico/metabolismo , Estresse Psicológico/psicologia
9.
Int J Med Sci ; 18(16): 3665-3673, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34790038

RESUMO

Menopause is the leading cause of osteoporosis for elderly women due to imbalanced bone remodelling in the absence of oestrogen. The ability of tocotrienol in reversing established bone loss due to oestrogen deficiency remains unclear despite the plenitude of evidence showcasing its preventive effects. This study aimed to investigate the effects of self-emulsified annatto tocotrienol (SEAT) on bone histomorphometry and remodelling in ovariectomised rats. Female Sprague Dawley rats (n=36) were randomly assigned into baseline, sham, ovariectomised (OVX) control, OVX-treated with annatto tocotrienol (AT) (60 mg/kg), SEAT (60 mg/kg) and raloxifene (1 mg/kg). Daily treatment given through oral gavage was started two months after castration. The rats were euthanised after eight weeks of treatment. Blood was collected for bone biomarkers. Femur and lumbar bones were collected for histomorphometry and remodelling markers. The results showed that AT and SEAT improved osteoblast numbers and trabecular mineralisation rate (p<0.05 vs untreated OVX). AT also decreased skeletal sclerostin expression in OVX rats (p<0.05 vs untreated OVX). Similar effects were observed in the raloxifene-treated group. Only SEAT significantly increased bone formation rate and reduced RANKL/OPG ratio (p<0.05 vs untreated OVX). However, no changes in osteoclast-related parameters were observed among the groups (p>0.05). In conclusion, SEAT exerts potential skeletal anabolic properties by increasing bone formation, suppressing sclerostin expression and reducing RANKL/OPG ratio in rats with oestrogen deficiency.


Assuntos
Osso e Ossos/efeitos dos fármacos , Carotenoides/uso terapêutico , Osteoporose Pós-Menopausa/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Tocotrienóis/uso terapêutico , Animais , Bixaceae/química , Densidade Óssea/efeitos dos fármacos , Proteínas Morfogenéticas Ósseas/metabolismo , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Carotenoides/química , Carotenoides/farmacologia , Modelos Animais de Doenças , Emulsões , Estradiol/deficiência , Feminino , Marcadores Genéticos , Humanos , Osteoporose Pós-Menopausa/metabolismo , Osteoporose Pós-Menopausa/patologia , Osteoprotegerina/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ligante RANK/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Tocotrienóis/química , Tocotrienóis/farmacologia
10.
J Adv Nurs ; 77(9): 3933-3939, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34028853

RESUMO

AIMS: To determine the challenges perceived by final-year nursing students in the clinical learning environment. DESIGN: Data-based convergent mixed-method systematic review. METHODS: Three electronic databases (Web of Science, Scopus, and Cumulative Index to Nursing and Allied Health Literature) will be used in the identification stage. The first search will use the search string for each database to identify relevant studies. The articles retrieved will be screened by year of publication, article type and language. Abstracts and full-text of selected studies will be screened for eligibility independently by a minimum of two reviewers. The reference lists will be manually screened to identify additional publications. The quality assessment will be conducted by two reviewers using the Mixed Methods Appraisal Tools. Quantitative and mixed-method studies will be transformed into qualitative. A thematic approach will be used to synthesize and report the data. Ethics approval and funding have been approved in April 2020. DISCUSSION: This study will synthesize the types of challenges perceived by final-year undergraduate nursing students in different clinical learning environments across the country. IMPACT: The proposed study findings will help nursing education stakeholders and faculty provide assistance to final-year nursing students in their transition year to become registered nurses.


Assuntos
Bacharelado em Enfermagem , Educação em Enfermagem , Estudantes de Enfermagem , Humanos , Aprendizagem , Projetos de Pesquisa
11.
Int J Mol Sci ; 22(21)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34769045

RESUMO

Diabetes cardiomyopathy is one of the key factors of mortality among diabetic patients around the globe. One of the prior contributors to the progression of diabetic cardiomyopathy is cardiac mitochondrial dysfunction. The cardiac mitochondrial dysfunction can induce oxidative stress in cardiomyocytes and was found to be the cause of majority of the heart morphological and dynamical changes in diabetic cardiomyopathy. To slow down the occurrence of diabetic cardiomyopathy, it is crucial to discover therapeutic agents that target mitochondrial-induced oxidative stress. Flavonoid is a plentiful phytochemical in plants that shows a wide range of biological actions against human diseases. Flavonoids have been extensively documented for their ability to protect the heart from diabetic cardiomyopathy. Flavonoids' ability to alleviate diabetic cardiomyopathy is primarily attributed to their antioxidant properties. In this review, we present the mechanisms involved in flavonoid therapies in ameliorating mitochondrial-induced oxidative stress in diabetic cardiomyopathy.


Assuntos
Cardiomiopatias Diabéticas/tratamento farmacológico , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Humanos , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico
12.
Molecules ; 26(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070497

RESUMO

Chronic inflammation and oxidative stress are two major mechanisms leading to the imbalance between bone resorption and bone formation rate, and subsequently, bone loss. Thus, functional foods and dietary compounds with antioxidant and anti-inflammatory could protect skeletal health. This review aims to examine the current evidence on the skeletal protective effects of propolis, a resin produced by bees, known to possess antioxidant and anti-inflammatory activities. A literature search was performed using Pubmed, Scopus, and Web of Science to identify studies on the effects of propolis on bone health. The search string used was (i) propolis AND (ii) (bone OR osteoporosis OR osteoblasts OR osteoclasts OR osteocytes). Eighteen studies were included in the current review. The available experimental studies demonstrated that propolis could prevent bone loss due to periodontitis, dental implantitis, and diabetes in animals. Combined with synthetic and natural grafts, it could also promote fracture healing. Propolis protects bone health by inhibiting osteoclastogenesis and promoting osteoblastogenesis, partly through its antioxidant and anti-inflammatory actions. Despite the promising preclinical results, the skeletal protective effects of propolis are yet to be proven in human studies. This research gap should be bridged before nutraceuticals based on propolis with specific health claims can be developed.


Assuntos
Osso e Ossos/efeitos dos fármacos , Periodonto/efeitos dos fármacos , Própole/farmacologia , Animais , Antioxidantes/farmacologia , Abelhas , Reabsorção Óssea , Osteoblastos/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos
13.
Molecules ; 26(4)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557218

RESUMO

Metabolic syndrome is a constellation of five risk factors comprising central obesity, hyperglycaemia, dyslipidaemia, and hypertension, which predispose a person to cardiometabolic diseases. Many studies reported the beneficial effects of honey in reversing metabolic syndrome through its antiobesity, hypoglycaemic, hypolipidaemic, and hypotensive actions. This review aims to provide an overview of the mechanism of honey in reversing metabolic syndrome. The therapeutic effects of honey largely depend on the antioxidant and anti-inflammatory properties of its polyphenol and flavonoid contents. Polyphenols, such as caffeic acid, p-coumaric acid, and gallic acid, are some of the phenolic acids known to have antiobesity and antihyperlipidaemic properties. They could inhibit the gene expression of sterol regulatory element-binding transcription factor 1 and its target lipogenic enzyme, fatty acid synthase (FAS). Meanwhile, caffeic acid and quercetin in honey are also known to reduce body weight and fat mass. In addition, fructooligosaccharides in honey are also known to alter lipid metabolism by reducing FAS activity. The fructose and phenolic acids might contribute to the hypoglycaemic properties of honey through the phosphatidylinositol 3-kinase/protein kinase B insulin signalling pathway. Honey can increase the expression of Akt and decrease the expression of nuclear factor-kappa B. Quercetin, a component of honey, can improve vasodilation by enhancing nitric oxide production via endothelial nitric oxide synthase and stimulate calcium-activated potassium channels. In conclusion, honey can be used as a functional food or adjuvant therapy to prevent and manage metabolic syndrome.


Assuntos
Mel/análise , Síndrome Metabólica/tratamento farmacológico , Animais , Humanos
14.
Molecules ; 26(8)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33923673

RESUMO

BACKGROUND: Osteoporosis results from excessive bone resorption and reduced bone formation, triggered by sex hormone deficiency, oxidative stress and inflammation. Tanshinones are a class of lipophilic phenanthrene compounds found in the roots of Salvia miltiorrhiza with antioxidant and anti-inflammatory activities, which contribute to its anti-osteoporosis effects. This systematic review aims to provide an overview of the skeletal beneficial effects of tanshinones. METHODS: A systematic literature search was conducted in January 2021 using Pubmed, Scopus and Web of Science from the inception of these databases. Original studies reporting the effects of tanshinones on bone through cell cultures, animal models and human clinical trials were considered. RESULTS: The literature search found 158 unique articles on this topic, but only 20 articles met the inclusion criteria and were included in this review. The available evidence showed that tanshinones promoted osteoblastogenesis and bone formation while reducing osteoclastogenesis and bone resorption. CONCLUSIONS: Tanshinones modulates bone remodelling by inhibiting osteoclastogenesis and osteoblast apoptosis and stimulating osteoblastogenesis. Therefore, it might complement existing strategies to prevent bone loss.


Assuntos
Abietanos/farmacologia , Animais , Antioxidantes/farmacologia , Humanos , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos
15.
Molecules ; 26(6)2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33801011

RESUMO

Vitamin A is a fat-soluble micronutrient essential for growth, immunity, and good vision. The preformed retinol is commonly found in food of animal origin whereas provitamin A is derived from food of plant origin. This review summarises the current evidence from animal, human and cell-culture studies on the effects of vitamin A towards bone health. Animal studies showed that the negative effects of retinol on the skeleton were observed at higher concentrations, especially on the cortical bone. In humans, the direct relationship between vitamin A and poor bone health was more pronounced in individuals with obesity or vitamin D deficiency. Mechanistically, vitamin A differentially influenced the stages of osteogenesis by enhancing early osteoblastic differentiation and inhibiting bone mineralisation via retinoic acid receptor (RAR) signalling and modulation of osteocyte/osteoblast-related bone peptides. However, adequate vitamin A intake through food or supplements was shown to maintain healthy bones. Meanwhile, provitamin A (carotene and ß-cryptoxanthin) may also protect bone. In vitro evidence showed that carotene and ß-cryptoxanthin may serve as precursors for retinoids, specifically all-trans-retinoic acid, which serve as ligand for RARs to promote osteogenesis and suppressed nuclear factor-kappa B activation to inhibit the differentiation and maturation of osteoclasts. In conclusion, we suggest that both vitamin A and provitamin A may be potential bone-protecting agents, and more studies are warranted to support this hypothesis.


Assuntos
Osso e Ossos/metabolismo , Obesidade/metabolismo , Osteogênese , Receptores do Ácido Retinoico , Vitamina A/metabolismo , Deficiência de Vitamina D/metabolismo , Animais , Humanos
16.
Molecules ; 26(3)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513715

RESUMO

Phytochemical contents of honey are presumed to be beneficial to the female reproductive system (FRS). However, the biological effects of honey supplementation (HS) in vivo on the FRS remain unclear. This review aims to investigate the current literature on the effects of HS on the FRS, particularly on the sex hormone profile and reproductive organs (uterus and vagina). A systematic literature search using Scopus, MEDLINE via Ovid and Cochrane Library databases was conducted. Records were screened and identified for preclinical and clinical studies addressing the effects of HS on the FRS. Data on populations, interventions, outcomes and methodological quality were extracted. Studies were synthesised using tables and written summaries. Of the 198 identified records, six fulfilled the inclusion criteria. All six records were used for data extraction: two experimental studies using rats as the model organism and four human clinical studies of honey on female reproductive health. HS elevated the progesterone levels, restrained body weight increase, prevented uterine and vaginal atrophies in ovariectomised rats, attenuated symptoms of candidiasis and improved oxidative status in patients. Current evidence shows that short-term HS following surgical or physiological menopause exerts an oestrogenic, antioxidant and anti-inflammatory effect on the FRS. However, insufficient long-term studies preclude any definitive conclusions.


Assuntos
Produtos Biológicos/farmacologia , Genitália Feminina/efeitos dos fármacos , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Suplementos Nutricionais , Feminino , Genitália Feminina/metabolismo , Mel , Humanos , Progesterona/metabolismo , Útero/efeitos dos fármacos , Útero/metabolismo
17.
J Pak Med Assoc ; 71(Suppl 2)(2): S30-S36, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33785938

RESUMO

OBJECTIVE: This study aimed to investigate osteoporosis knowledge and bone health practices among students of a Malaysian public university. METHODS: A cross-sectional study was conducted amongst university students from a Malaysian's public university. A total of 228 students responded to a self-administered questionnaire consisting of items evaluating knowledge and practices of osteoporosis. RESULTS: The students showed a moderate level of osteoporosis awareness with a score of 63.3%. Male subjects had higher awareness scores of osteoporosis complications compared to female subjects (p= 0.010). Malay (p= 0.002) and Chinese (p= 0.005) had higher levels of osteoporosis awareness compared to Indian students. Coffee and alcohol intakes were significantly different between the sexes (p= 0.013) and the ethnic groups (p= 0.029). Most of the subjects in our study were minimally active (43.9%). CONCLUSIONS: The students had a reasonable levels of knowledge about osteoporosis, but their health activities to avoid osteoporosis were insufficient. This illustrates the need for educational programmes to improve students' knowledge and awareness for successful osteoporosis prevention.


Assuntos
Osteoporose , Universidades , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Osteoporose/epidemiologia , Osteoporose/prevenção & controle , Estudantes , Inquéritos e Questionários
18.
Aging Male ; 23(5): 327-334, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29495911

RESUMO

This study aimed to compare the skeletal effect between GnRH agonist therapy and orchidectomy in male rats assessed using serum turnover markers and bone histomorphometry. Three-month-old male Sprague-Dawley rats (n = 46) were divided into three experimental arms, baseline, buserelin, and orchidectomy. In the buserelin arm, the rats received a daily subcutaneous injection of either normal saline or buserelin acetate at 25 µg/kg or 75 µg/kg. In the orchidectomy arm, the rats were either sham-operated or orchidectomized. The rats were euthanized after the three-month treatment. Blood was collected for the evaluation of bone turnover markers. Femurs were harvested for bone histomorphometry examination. A significant increase in serum C-telopeptide of type 1 collagen was observed in the orchidectomized group compared with the sham group (p < .05). Structural histomorphometry analysis showed that both buserelin (25 µg/kg and 75 µg/kg) and orchidectomy significantly decreased the trabecular bone volume, number and significantly increased trabecular separation in rats compared with their respective controls (p < .05). Osteoclast number and eroded surface were significantly increased in both buserelin (25 µg/kg and 75 µg/kg) and orchidectomized group compared with their respective controls (p < .05). As a conclusion, buserelin causes deterioration of bone microarchitecture and increased bone resorption similar to orchidectomy after three months.


Assuntos
Busserrelina , Orquiectomia , Animais , Remodelação Óssea , Osso e Ossos , Hormônio Liberador de Gonadotropina , Masculino , Ratos , Ratos Sprague-Dawley
19.
Int J Med Sci ; 17(11): 1625-1638, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32669965

RESUMO

Oxidative stress and inflammation are two interlinked events that exist simultaneously in metabolic syndrome (MetS) and its related complications. These pathophysiological processes can be easily triggered by each other. This review summarizes the current evidence from animal and human studies on the effects of vitamin C in managing MetS. In vivo studies showed promising effects of vitamin C, but most of the interventions used were in combination with other compounds. The direct effects of vitamin C remain to be elucidated. In humans, the current state of evidence revealed that lower vitamin C intake and circulating concentration were found in MetS subjects. A negative relationship was observed between vitamin C intake / concentration and the risk of MetS. Oral supplementation of vitamin C also improved MetS conditions. It has been postulated that the positive outcomes of vitamin C may be in part mediated through its anti-oxidative and anti-inflammatory properties. These observations suggest the importance of MetS patients to have an adequate intake of vitamin C through food, beverages or supplements in order to maintain its concentration in the systemic circulation and potentially reverse MetS.


Assuntos
Antioxidantes/uso terapêutico , Ácido Ascórbico/uso terapêutico , Síndrome Metabólica/tratamento farmacológico , Animais , Humanos , Inflamação/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos
20.
Int J Med Sci ; 17(16): 2585-2593, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33029101

RESUMO

Objectives: Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that elevates the individual risk of cardiovascular diseases. These abnormalities are also known to alter bone remodelling. Therefore, MetS may be associated with osteoporosis. This study aims to determine the association between MetS and its components and bone mineral density (BMD) assessed by dual-energy X-ray absorptiometry (DXA) among Malaysians. Methods: 400 Malaysians aged ≥ 40 years (52.5% women) residing in Klang Valley, Malaysia, were recruited. Subjects' demographic and lifestyle details were collected using a questionnaire, and blood pressure and body anthropometry were measured. Subjects' lumbar spine and total hip BMD were measured by DXA. Their fasting blood was collected for blood glucose level and lipid profile analysis. Regression analysis was used to analyze the relationship between MetS or its components and BMD. Results: Subjects with MetS had higher BMD compared to subjects without MetS in models unadjusted for BMI (spine p=0.008; hip p<0.001). This difference was attenuated with BMI adjustment (spine p=0.625; hip p=0.478). Waist circumference was associated positively with BMD in models unadjusted for BMI (spine p=0.012; hip p<0.001), but the association became negative with BMI adjustment (spine p=0.044; hip p=0.021). Systolic blood pressure was associated positively with total hip BMD (p=0.019) but BMI adjustment attenuated the relationship (p=0.080). Triglyceride level was associated with osteoporosis in a fully adjusted model (p=0.001). Overall, MetS was associated with osteoporosis (p=0.019) but lifestyle (p=0.188) and BMI adjustment attenuated the relationship (p=0.904). Conclusion: MetS is positively associated with BMD, and this relationship is predominantly mediated by BMI. Although MetS is not a significant risk factor for osteoporosis, the inverse relationship between waist circumference, a marker of central obesity, and BMD highlights the need to prevent adiposity to improve metabolic and skeletal health.


Assuntos
Densidade Óssea/fisiologia , Síndrome Metabólica/complicações , Obesidade Abdominal/epidemiologia , Osteoporose/epidemiologia , Absorciometria de Fóton/estatística & dados numéricos , Idoso , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Malásia/epidemiologia , Masculino , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Obesidade Abdominal/etiologia , Obesidade Abdominal/fisiopatologia , Osteoporose/diagnóstico , Osteoporose/etiologia , Osteoporose/fisiopatologia , Medição de Risco/estatística & dados numéricos , Fatores de Risco , Circunferência da Cintura
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