RESUMO
PURPOSE: The Bone And MicroBiOme Onset (BAMBOO) study is an ongoing prospective observational cohort study conducted in Tianjin, China, aiming to determine age-appropriate trajectories for microbiome maturation and bone development and to identify the influence of dietary factors in the process. PARTICIPANTS: The recruitment started in September 2021 and was completed in February 2023. A total of 1380 subjects were recruited, 690 at birth (group 1) and 690 at 6 months of age (group 2). Groups 1 and 2 will be followed up for 12 months and 36 months, respectively. FINDINGS TO DATE: The age of the mothers was 31.1±3.7 (mean±SD), and the birth weight of infants was 3.3±0.5 kg with an incidence of caesarean section 50.4%. Food diary information of the first 100 subjects showed that 64 food items were introduced by 6 months. A pilot microbiome analysis revealed that at the species level, bacterial communities were composed of mostly Bacteroides dorei, Bacteroides vulgatus and Escherichia coli, which were consistent with that of previous reports. Feasibility assessments of breast milk vitamin D and human milk oligosaccharides were validated through certified reference measurements. The early data assessment showed a high reliability of the data generated from this study. FUTURE PLANS: Data collection will be completed in August 2025. Four stage-statistical analyses will be performed as the cohort reaches certain age thresholds before the final report. Analysis of BAMBOO data will be used to develop age-appropriate trajectories for microbiome maturation and bone development for children aged 0-3 years and investigate the contribution of dietary factors in the process. TRIAL REGISTRATION NUMBER: ChiCTR2100049972.
Assuntos
Desenvolvimento Ósseo , Humanos , China , Lactente , Feminino , Estudos Prospectivos , Recém-Nascido , Masculino , Desenvolvimento Ósseo/fisiologia , Leite Humano/microbiologia , Microbioma Gastrointestinal/fisiologia , Adulto , Pré-Escolar , Vitamina D , Dieta , Estudos de CoortesRESUMO
A probiotic-related benefit for the host is inherently linked to metabolic activity and integration in the gut ecosystem. To facilitate these, probiotics are often combined with specific prebiotics in a synbiotic formulation. Here, we propose an approach for improving probiotic metabolic activity and engraftment. By cultivating the probiotic strain in the presence of a specific prebiotic (preconditioning), the bacterial enzymatic machinery is geared towards prebiotic consumption. Today, it is not known if preconditioning constitutes an advantage for the synbiotic concept. Therefore, we assessed the effects galacto-oligosaccharide (GOS) addition and preconditioning on GOS of Limosilactobacillus reuteri DSM 17938 on ex vivo colonic metabolic profiles, microbial community dynamics, and osteoblastogenesis. We show that adding GOS and preconditioning L. reuteri DSM 17938 act on different scales, yet both increase ex vivo short-chain fatty acid (SCFA) production and engraftment within the microbial community. Furthermore, preconditioned supernatants or SCFA cocktails mirroring these profiles decrease the migration speed of MC3T3-E1 osteoblasts, increase several osteogenic differentiation markers, and stimulate bone mineralization. Thus, our results demonstrate that preconditioning of L. reuteri with GOS may represent an incremental advantage for synbiotics by optimizing metabolite production, microbial engraftment, microbiome profile, and increased osteoblastogenesis.
Assuntos
Limosilactobacillus reuteri , Microbiota , Probióticos , Osteogênese , Probióticos/farmacologia , Prebióticos , Oligossacarídeos/farmacologia , Oligossacarídeos/metabolismo , Ácidos Graxos VoláteisRESUMO
The beneficial health effects of phytochemicals depend on their bioavailability and the form under which they reach systemic circulation, usually as phase II metabolites. The lack of authentic standards for these metabolites makes their quantification in biological samples challenging. A new analytical approach to get a more accurate quantification of oleuropein metabolites in biological samples after ingestion of olive leaf extract was proposed. This approach was based on the calculation of a response factor in QTOF MS for each metabolite, comparing their quantification in UV and MS using urine samples concentrated in the metabolites of interest. Glucuronide and sulfate conjugates of hydroxytyrosol and homovanillyl alcohol were more accurately quantified in plasma and urine and for the first time, oleuropein aglycone conjugates and their hydroxylated and hydrogenated derivatives were quantified after consumption of olive products. This approach could be extensible to the analysis of other phenolic metabolites when authentic standards are not available, opening a valuable method for bioavailability studies.
Assuntos
Glucuronídeos , Iridoides , Humanos , Glucosídeos Iridoides , Olea , Extratos Vegetais , SulfatosRESUMO
The health effects of (poly)phenols (PPs) depend upon their bioavailability that, in general, is very low and shows a high interindividual variability. The low bioavailability of PPs is mainly attributed to their low absorption in the upper gastrointestinal tract as a result of their low water solubility, their presence in foods as polymers or in glycosylated forms, and their tight bond to food matrices. Although many studies have investigated how technological and biotechnological processes affect the phenolic composition of fruits and vegetables, limited information exists regarding their effects on PP bioavailability in humans. In the present review, the effect of food processing (mechanical, thermal, and non-thermal treatments), oral-delivery nanoformulations, enzymatic hydrolysis, fermentation, co-administration with probiotics, and generation of postbiotics in PP bioavailability have been overviewed, focusing in the evidence provided in humans.
Assuntos
Dieta , Fenóis , Disponibilidade Biológica , Frutas/química , Humanos , Fenóis/química , Polifenóis/análise , VerdurasRESUMO
The need to consume adequate dietary protein to preserve physical function during ageing is well recognized. However, the effect of protein intakes on glucose metabolism is still intensively debated. During age-related estrogen withdrawal at the time of the menopause, it is known that glucose homeostasis may be impaired but the influence of dietary protein levels in this context is unknown. The aim of the present study is to elucidate the individual and interactive effects of estrogen deficiency and suboptimal protein intake on glucose homeostasis in a preclinical model involving ovariectomy (OVX) and a 13 week period of a moderately reduced protein intake in 7 month-old ageing rats. To investigate mechanisms of action acting via the pancreas-liver-muscle axis, fasting circulating levels of insulin, glucagon, IGF-1, FGF21 and glycemia were measured. The hepatic lipid infiltration and the protein expression of GLUT4 in the gastrocnemius were analyzed. The gene expression of some hepatokines, myokines and lipid storage/oxidation related transcription factors were quantified in the liver and the gastrocnemius. We show that, regardless of the estrogen status, moderate dietary protein restriction increases fasting glycemia without modifying insulinemia, body weight gain and composition. This fasting hyperglycemia is associated with estrogen status-specific metabolic alterations in the muscle and liver. In estrogen-replete (SHAM) rats, GLUT4 was down-regulated in skeletal muscle while in estrogen-deficient (OVX) rats, hepatic stress-associated hyperglucagonemia and high serum FGF21 were observed. These findings highlight the importance of meeting dietary protein needs to avoid disturbances in glucose homeostasis in ageing female rats with or without estrogen withdrawal.
Assuntos
Dieta com Restrição de Proteínas , Estrogênios , Animais , Glicemia/metabolismo , Proteínas Alimentares , Feminino , Homeostase , Lipídeos , RatosRESUMO
OBJECTIVES: To investigate a 6-month intervention with an olive leaf extract (OLE) on knee functionality and biomarkers of bone/cartilage metabolism and inflammation. DESIGN: This randomized, double-blind, placebo-controlled, multi-centric trial included 124 subjects with knee pain or mobility issues. Subjects received twice a day one capsule of placebo or 125 mg OLE (Bonolive™, an OLE containing 50 mg of oleuropein) for 6 months. The co-primary endpoints were Knee injury and Osteoarthritis Outcome Score (KOOS) and serum Coll2-1NO2. The secondary endpoints were the subscales of the KOOS, knee pain VAS at rest and at walking, OARSI core set of performance-based tests and multiple inflammatory and bone or cartilage remodeling serum biomarkers and concentration of oleuropein's metabolites in urine. RESULTS: At 6 months, OLE group was not efficient on global KOOS score, changes of inflammatory and cartilage remodeling biomarkers compared to placebo. Post hoc analyses demonstrated a large and significant treatment effect of OLE in a sub-group of subjects with high walking pain at baseline (p = 0.03). This was observed at 6 months for the global KOOS score, and each different subscale and for pain at walking (p = 0.02). OLE treatment was well tolerated. CONCLUSION: OLE was not effective on joint discomfort excepted in a sub-group of subjects with high pain at treatment initiation. As oleuropein is well tolerated, OLE can be used to relieve knee joint pain and enhance mobility in subjects with articular pain.
RESUMO
With age, the physiological responses to occasional or regular stressors from a broad range of functions tend to change and adjust at a different pace and restoring these functions in the normal healthy range becomes increasingly challenging. Even if this natural decline is somehow unavoidable, opportunities exist to slow down and attenuate the impact of advancing age on major physiological processes which, when weakened, constitute the hallmarks of aging. This narrative review revisits the current knowledge related to the aging process and its impact on key metabolic functions including immune, digestive, nervous, musculoskeletal, and cardiovascular functions; and revisits insights into the important biological targets that could inspire effective strategies to promote healthy aging.
RESUMO
CONTEXT: Citrus fruits contain unique flavanones. One of the most abundant of the flavanones, hesperidin, has been shown to prevent bone loss in ovariectomized rats. OBJECTIVE: The objective of the study was to measure the effect of hesperidin with or without calcium supplementation on bone calcium retention in postmenopausal women. DESIGN: The study was a double-blind, placebo-controlled, randomized-order crossover design of 500 g hesperidin with or without 500 mg calcium supplement in 12 healthy postmenopausal women. Bone calcium retention was determined from urinary excretion of the rare isotope, (41)Ca, from bone. RESULTS: Calcium plus hesperidin, but not hesperidin alone, improved bone calcium retention by 5.5% (P < .04). CONCLUSION: Calcium supplementation (Calcilock), in combination with hesperidin, is effective at preserving bone in postmenopausal women.
Assuntos
Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Cálcio da Dieta/administração & dosagem , Cálcio/metabolismo , Hesperidina/administração & dosagem , Pós-Menopausa , Idoso , Radioisótopos de Cálcio/urina , Estudos Cross-Over , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/prevenção & controle , PlacebosRESUMO
Step-reduction (SR) in older adults results in muscle atrophy and an attenuated rise in postprandial muscle protein synthesis (MPS): anabolic resistance. Knowing that resistance exercise (RT) can enhance MPS, we examined whether RT could enhance MPS following 2 weeks of SR. In addition, as we postulated that SR may impair feeding-induced vasodilation limiting nutrient delivery to muscle, we also examined whether citrulline (CIT), as an arginine and nitric oxide precursor, could attenuate muscle anabolic resistance accompanying SR. We used a unilateral leg model to compare older subjects' who had undergone SR to a loaded condition of SR plus RT (SR + RT). Thirty older men (70 ± 1 years) underwent 14 days of SR (<1500 steps/day) with supplementation of either 5 g/day CIT or glycine placebo. Throughout SR, subjects performed unilateral low-load RT thrice weekly. We assessed muscle protein synthesis in the postabsorptive and postprandial state (20 g whey isolate plus 15 g glycine or as micellar-whey with 5 g CIT or 15 g glycine, n = 10/group). As MPS was similar after ingestion of either whey isolate, micellar-whey, or micellar-whey + CIT data related to different dietary groups were collapsed to compare SR and SR + RT legs. Subjects' daily steps were reduced by 80 ± 2% during SR (P < 0.001) compared with baseline. Leg fat-free mass decreased with SR (-124 ± 61 g) and increased in the SR + RT (+126 ± 68 g; P = 0.003). Myofibrillar FSR was lower (P < 0.0001) in the SR as compared with the SR + RT leg in the postabsorptive (0.026 ± 0.001%/h vs. 0.045 ± 0.001%/h) and postprandial states (0.055 ± 0.002%/h vs. 0.115 ± 0.003%/h). We conclude that low-load RT, but not supplementation with CIT, can attenuate the deleterious effects of SR in aging muscle.
RESUMO
AIM: The aim of this work was to evaluate the effects of carnosol, a rosemary polyphenol, on pro-inflammatory and catabolic mediators of cartilage breakdown in chondrocytes and via bone-cartilage crosstalk. MATERIALS AND METHODS: Osteoarthritic (OA) human chondrocytes were cultured in alginate beads for 4 days in presence or absence of carnosol (6 nM to 9 µM). The production of aggrecan, matrix metalloproteinase (MMP)-3, tissue inhibitor of metalloproteinase (TIMP)-1, interleukin (IL)-6 and nitric oxide (NO) and the expression of type II collagen and ADAMTS-4 and -5 were analyzed. Human osteoblasts from sclerotic (SC) or non-sclerotic (NSC) subchondral bone were cultured for 3 days in presence or absence of carnosol before co-culture with chondrocytes. Chondrocyte gene expression was analyzed after 4 days of co-culture. RESULTS: In chondrocytes, type II collagen expression was significantly enhanced in the presence of 3 µM carnosol (p = 0.008). MMP-3, IL-6, NO production and ADAMTS-4 expression were down-regulated in a concentration-dependent manner by carnosol (p<0.01). TIMP-1 production was slightly increased at 3 µM (p = 0.02) and ADAMTS-5 expression was decreased from 0.2 to 9 µM carnosol (p<0.05). IL-6 and PGE2 production was reduced in the presence of carnosol in both SC and NSC osteoblasts while alkaline phosphatase activity was not changed. In co-culture experiments preincubation of NSC and SC osteoblasts wih carnosol resulted in similar effects to incubation with anti-IL-6 antibody, namely a significant increase in aggrecan and decrease in MMP-3, ADAMTS-4 and -5 gene expression by chondrocytes. CONCLUSIONS: Carnosol showed potent inhibition of pro-inflammatory and catabolic mediators of cartilage breakdown in chondrocytes. Inhibition of matrix degradation and enhancement of formation was observed in chondrocytes cocultured with subchondral osteoblasts preincubated with carnosol indicating a cross-talk between these two cellular compartments, potentially mediated via inhibition of IL-6 in osteoblasts as similar results were obtained with anti-IL-6 antibody.
Assuntos
Abietanos/farmacologia , Anti-Inflamatórios/farmacologia , Condrócitos/efeitos dos fármacos , Condrócitos/patologia , Osteoartrite/tratamento farmacológico , Osteoartrite/imunologia , Agrecanas/imunologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Condrócitos/imunologia , Técnicas de Cocultura , Dinoprostona/imunologia , Humanos , Interleucina-6/imunologia , Metaloproteinase 3 da Matriz/imunologia , Osteoartrite/patologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/imunologia , Osteoblastos/patologia , Inibidor Tecidual de Metaloproteinase-1/imunologiaRESUMO
Population ageing has emerged as a major demographic trend worldwide due to improved health and longevity. This global ageing phenomenon will have a major impact on health-care systems worldwide due to increased morbidity and greater needs for hospitalization/institutionalization. As the ageing population increases worldwide, there is an increasing awareness not only of increased longevity but also of the importance of "healthy ageing" and "quality of life". Yet, the age related chronic inflammation is believed to be pathogenic with regards to its contribution to frailty and degenerative disorders. In particular, the frailty syndrome is increasingly being considered as a key risk indicator of adverse health outcomes. In addition, elderly may be also prone to be resistant to anabolic stimuli which is likely a key factor in the loss of skeletal muscle mass with ageing. Vital to understand these key biological processes is the development of biological markers, through system biology approaches, aiding at strategies for tailored therapeutic and personalized nutritional program. Overall aim is to prevent or attenuate decline of key physiological functions required to live an active, independent life. This review focus on core indicators of health and functions in older adults, where nutrition and tailored personalized programs could exhibit preventive roles, and where the aid of metabolomics technologies are increasingly displaying potential in revealing key molecular mechanisms/targets linked to specific ageing and/or healthy ageing processes.
RESUMO
Population ageing has emerged as a major demographic trend worldwide due to improved health and longevity. This global ageing phenomenon will have a major impact on health-care systems worldwide due to increased morbidity and greater needs for hospitalization/institutionalization. As the ageing population increases worldwide, there is an increasing awareness not only of increased longevity but also of the importance of "healthy ageing" and "quality of life". Yet, the age related chronic inflammation is believed to be pathogenic with regards to its contribution to frailty and degenerative disorders. In particular, the frailty syndrome is increasingly being considered as a key risk indicator of adverse health outcomes. In addition, elderly may be also prone to be resistant to anabolic stimuli which is likely a key factor in the loss of skeletal muscle mass with ageing. Vital to understand these key biological processes is the development of biological markers, through system biology approaches, aiding at strategies for tailored therapeutic and personalized nutritional program. Overall aim is to prevent or attenuate decline of key physiological functions required to live an active, independent life. This review focus on core indicators of health and functions in older adults, where nutrition and tailored personalized programs could exhibit preventive roles, and where the aid of metabolomics technologies are increasingly displaying potential in revealing key molecular mechanisms/targets linked to specific ageing and/or healthy ageing processes.
Assuntos
Envelhecimento , Biomarcadores/metabolismo , Músculo Esquelético/metabolismo , Osteoporose/metabolismo , Idoso , Idoso de 80 Anos ou mais , Feminino , Idoso Fragilizado , Humanos , Sistema Imunitário , Inflamação , Longevidade , Masculino , Metabolômica , Ciências da Nutrição , Fenótipo , Fatores de RiscoRESUMO
Osteoporosis is a skeletal disease characterized by a decrease in bone mass and bone quality that predispose an individual to an increased risk of fragility fractures. Evidence demonstrating a positive link between certain dietary patterns (e.g. Mediterranean diet or high consumption of fruits and vegetables) and bone health highlights an opportunity to investigate their potential to protect against the deterioration of bone tissue during ageing. While the list of these phytonutrients is extensive, this review summarizes evidence on some which are commonly consumed and have gained increasing attention over recent years, including lycopene and various polyphenols (e.g. polyphenols from tea, grape seed, citrus fruit, olive and dried plum). Evidence to define a clear link between these phytonutrients and bone health is currently insufficient to generate precise dietary recommendations, owing to mixed findings or a scarcity in clinical data. Moreover, their consumption typically occurs within the context of a diet consisting of a mix of phytonutrients and other nutrients rather than in isolation. Future clinical trials that can apply a robust set of outcome measurements, including the determinants of bone strength, such as bone quantity (i.e. bone mineral density) and bone quality (i.e. bone turnover and bone microarchitecture), will help to provide a more comprehensive outlook on how bone responds to these various phytonutrients. Moreover, future trials that combine these phytonutrients with established bone nutrients (i.e. calcium and vitamin D) are needed to determine whether combined strategies can produce more robust effects on skeletal health.
Assuntos
Envelhecimento/fisiologia , Osso e Ossos/efeitos dos fármacos , Dieta , Frutas/química , Micronutrientes/administração & dosagem , Osteoporose/prevenção & controle , Verduras/química , Fatores Etários , Densidade Óssea/efeitos dos fármacos , Cálcio da Dieta/farmacologia , Dieta Mediterrânea , Humanos , Micronutrientes/farmacologia , Fitoterapia/métodosRESUMO
Vitamin D requires two metabolic steps to become biologically active. In a first step 25-hydroxyvitamin D3 is formed, which acts as storage form. After a tightly controlled step in kidney the active metabolite 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) is formed. Because kidney is the relevant metabolic organ for this conversion, 1,25(OH)2D3 needs to be supplemented in patients with kidney malfunction or kidney failure. Synthetic 1,25(OH)2D3 (calcitriol) has been available as a drug for decades. Due to its high potency and its kinetic profile (fast absorption and rapid elimination) its therapeutic windows has proven to be relatively narrow. A natural form of the active metabolite was identified in a few plants, such as Solanum glaucophyllum (SG) and suggested as alternative for animal and human health. An extract of a SG variety bred for high and uniform level of glycosylated 1,25(OH)2D3 was chemically characterized. Among the typical pharmaceutically inactive plant components (carbohydrates 54.3%, protein 24.9%, minerals 17.1% and water 4.1%) high levels of 1,25(OH)2D3 and a unique flavonoid content was found (1.11mg total quercetin/g extract) consisting exclusively of the quercetin glycosides hyperoside, isoquercetin, rutin and apinosylrutin. The molecular distribution of glycosyl moieties in 1,25(OH)2D3 extracted from SG as determined by gel permeation chromatography was found to be 1-10 hexose units per aglycone. 1,25(OH)2D3-1-ß-glucopyranoside was identified in the SG extract, while a di- and triglycoside have been identified in SG by other groups. The pharmacokinetic properties of synthetic 1,25(OH)2D3 and glycosylated 1,25(OH)2D3 extracted from SG were compared in male rats. When compared to synthetic 1,25(OH)2D3, SG-derived 1,25(OH)2D3 exhibited delayed absorption and elimination characteristics, resulting in delayed Tmax (6-12h vs. 1h) and increased T½ (approximately 30h vs. 23h). This putative modified release pattern may be attributed to the glycosylation of herbal 1,25(OH)2D3 because de-glycosylation by ubiquitous intestinal enzymes prior to intestinal uptake of the aglycone appears to be the rate limiting step. In effect, 1,25(OH)2D3 of herbal origin behaves like a precursor of calcitriol, resulting in a wider therapeutic window and thus better pharmacological tolerance. This article is part of a Special Issue entitled 'Vitamin D Workshop.'.
Assuntos
Calcitriol/análogos & derivados , Animais , Calcitriol/sangue , Calcitriol/síntese química , Calcitriol/farmacocinética , Calcitriol/toxicidade , Preparações de Ação Retardada/isolamento & purificação , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/toxicidade , Humanos , Masculino , Preparações de Plantas/isolamento & purificação , Preparações de Plantas/farmacocinética , Preparações de Plantas/toxicidade , Ratos , Solanum glaucophyllum/químicaRESUMO
From a nutritional point of view, several factors are involved in ensuring optimal bone health. The most documented of these are calcium and vitamin D. However, it is now well acknowledged that some phytochemicals, also known as phytonutrients, which are plant-based compounds that are present in our daily diet, can positively regulate a number of physiological functions in mammalian systems involved in chronic diseases such as osteoporosis. Indeed, emerging data in animal models of postmenopausal osteoporosis has shown that exposure to some of these naturally plant-derived compounds (e.g. flavonoids) positively influences bone metabolism through preserved bone mineral density. In vitro experiments with bone cells have reported cellular and molecular mechanisms of phytonutrients involved in bone metabolism. Indeed, phytonutrients and especially polyphenols can act on both osteoblasts and osteoclasts to modulate bone metabolism, a balance between both cell type activities being required for bone health maintenance. To date, most studies investigating the effects of polyphenols on osteoblast cells have reported involvement of complex networks of anabolic signalling pathways such as BMPs or estrogen receptor mediated pathways. This review will report on the interaction between phytochemicals and bone metabolism in cell or animal models with a particular focus on the molecular mechanisms involved in the bone anabolic response.
Assuntos
Densidade Óssea/efeitos dos fármacos , Plantas/química , Polifenóis/farmacologia , Osso e Ossos/metabolismo , Carotenoides/química , Carotenoides/farmacologia , Carotenoides/uso terapêutico , Catequina/análogos & derivados , Catequina/química , Catequina/farmacologia , Catequina/uso terapêutico , Flavonoides/química , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Humanos , Lignanas/química , Lignanas/farmacologia , Lignanas/uso terapêutico , Osteoporose/tratamento farmacológico , Osteoporose/prevenção & controle , Polifenóis/química , Polifenóis/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Estilbenos/química , Estilbenos/farmacologia , Estilbenos/uso terapêuticoRESUMO
The effect of hesperidin (Hp) and naringin (Nar), two major citrus flavanones, on the regulation of bone metabolism was examined in male senescent rats. Twenty -month -old gonad-intact male Wistar rats received a casein-based diet supplemented with or without either 0.5% hesperidin (Hp), 0.5% naringin (Nar) or a mix of both flavanones (Hp+Nar, 0.25% each). After 3 months, daily Hp intake significantly improved femoral bone integrity as reflected by improvements in total and regional bone mineral densities (BMD) (9.7%-12.3% improvements, p<0.05) and trabecular bone volume fraction (24.3% improvement, p<0.05) at the femur compared with control group. In contrast, naringin exerted site-specific effects on BMD (10.2% improvement at the distal metaphyseal area, p<0.05) and no further benefit to bone mass was observed with the mix of flavanones. Bone resorption (DPD) was significantly attenuated by Hp and Nar given alone (40.3% and 26.8% lower compared to control, p<0.05, respectively) but not by the mixture of the two. All treatments significantly reduced expression of inflammatory markers to a similar extent (IL-6, 81.0-87.9% reduction; NO, 34.7-39.5% reduction) compared to control. Bone formation did not appear to be strongly affected by any of the treatments (no effect on osteocalcin levels, modest modulation of tibial BMP-2 mRNA). However, as previously reported, plasma lipid-lowering effects were observed with Hp and Nar alone (34.1%-45.1% lower for total cholesterol and triglycerides compared to control, p<0.05) or together (46% lower for triglycerides, p<0.05). Surprisingly the plasma circulating level of naringin (8.15µM) was >5-fold higher than that of hesperidin (1.44µM) at equivalent doses (0.5%) and a linear reduction in plasma levels was observed upon co-administration (0.25% each) indicating absence of competition for their intestinal absorption sites and metabolism. The higher efficacy of Hp at a lower plasma concentration than naringin, as well as the identification of the major circulating metabolite of hesperidin (hesperetin-7-O-glucuronide) underlines the importance of flavanone bioavailability and metabolism in their biological efficacy and suggests a structure-function relationship in the mechanism of action of the active metabolites.
Assuntos
Osso e Ossos/efeitos dos fármacos , Citrus/química , Flavanonas/farmacologia , Envelhecimento , Animais , Sequência de Bases , Peso Corporal/efeitos dos fármacos , Densidade Óssea , Primers do DNA , Flavanonas/farmacocinética , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Wistar , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em TandemRESUMO
Citrus fruit hesperidin is hydrolyzed by gut microflora into aglycone form (hesperetin) and then conjugated mainly into glucuronides. We previously demonstrated that hesperetin enhanced osteoblast differentiation. In this study, we examined the effect of hesperetin-7-O-glucuronide (Hp7G) on primary rat osteoblast proliferation and differentiation. The impact of Hp7G on specific bone signaling pathways was explored. Osteoblasts were exposed to physiological concentrations of 1 (Hp7G1) and 10 (Hp7G10) microM of conjugate. The glucuronide did not affect proliferation but enhanced differentiation by significantly increasing alkaline phosphatase (ALP) activity from day 14 of exposure. Hp7G significantly induced mRNA expression of ALP, Runx2, and Osterix after 48 h of exposure. Moreover, phosphorylation of Smad1/5/8 was enhanced by Hp7G, while ERK1/2 remained unchanged after 48 h. Hp7G decreased RANKL gene expression. These results suggest that Hp7G may regulate osteoblast differentiation through Runx2 and Osterix stimulation, and might be implicated in the regulation of osteoblast/osteoclast communication.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Glucuronídeos/farmacologia , Hesperidina/metabolismo , Osteoblastos/citologia , Animais , Células Cultivadas , Expressão Gênica/efeitos dos fármacos , Glucuronídeos/metabolismo , Hesperidina/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Ratos , Ratos WistarRESUMO
Hesperidin found in citrus fruits has been reported to be a promising bioactive compound for maintaining an optimal bone status in ovariectomized rodent models. In this study, we examined the capacity of hesperetin (Hp) to affect the proliferation, differentiation and mineralization of rodent primary osteoblasts. Then, the impact of Hp on signalling pathways known to be implicated in bone formation was explored. We exposed osteoblasts to physiological concentrations of 1 microM Hp (Hp1) and 10 microM Hp (Hp10). Neither proliferation nor mineralization was affected by Hp at either dose during 19 days of exposure. Hp at both doses enhanced differentiation by significantly increasing alkaline phosphatase (ALP) activity from Day 14 of exposure (Day 19: Hp1: +9%, Hp10: +14.8% vs. control; P<.05). However, Hp did not induce an obvious formation of calcium nodules. The effect of Hp10 on ALP was inhibited by addition of noggin protein, suggesting a possible action of this flavanone through the bone morphogenetic protein (BMP) pathway. Indeed, Hp10 significantly induced (1.2- to 1.4-fold) mRNA expression of genes involved in this signalling pathway (i.e., BMP2, BMP4, Runx2 and Osterix) after 48 h of exposure. This was strengthened by enhanced phosphorylation of the complex Smad1/5/8. Osteocalcin mRNA level was up-regulated by Hp only at 10 microM (2.2 fold vs. control). The same dose of Hp significantly decreased osteopontin (OPN) protein level (50% vs. control) after 14 days of culture. Our findings suggest that Hp may regulate osteoblast differentiation through BMP signalling and may influence the mineralization process by modulating OPN expression.
Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Diferenciação Celular/efeitos dos fármacos , Hesperidina/farmacologia , Osteoblastos/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Animais , Proteínas Morfogenéticas Ósseas/genética , Proteínas de Transporte/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Hesperidina/antagonistas & inibidores , Hesperidina/farmacocinética , Minerais/metabolismo , Osteoblastos/citologia , Osteocalcina/genética , Osteocalcina/metabolismo , Osteopontina/genética , Osteopontina/metabolismo , Fosforilação/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Proteínas Smad/genética , Proteínas Smad/metabolismo , Fatores de Tempo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Peak bone mass is a major determinant of osteoporosis pathogenesis during aging. Respective influences of energy and protein supplies on skeletal growth remains unclear. We investigated the effect of a 5-mo dietary restriction on bone status in young rats randomized into six groups (n = 10 per group). Control animals were fed a diet containing a normal (13%) (C-NP) or a high-protein content (26%) (C-HP). The other groups received a 40% protein energy-restricted diet (PER-NP and PER-HP) or a 40% energy-restricted diet (ER-NP and ER-HP). High-protein intake did not modulate bone acquisition, although a metabolic acidosis was induced and calcium retention impaired. PER and ER diets were associated with a decrease in femoral bone mineral density. The compensation for protein intake in energy-restricted conditions induced a bone sparing effect. Plasma osteocalcin (OC) and urinary deoxypyridinoline (DPD) assays revealed a decreased OC/DPD ratio in restricted rats compared with C animals, which was far more reduced in PER than in ER groups. Circulating IGF-1 levels were lowered by dietary restrictions. In conclusion, both energy and protein deficiencies may contribute to impairment in peak bone mass acquisition, which may affect skeleton strength and potentially render individuals more susceptible to osteoporosis.
Assuntos
Osso e Ossos/patologia , Suplementos Nutricionais , Aminoácidos/urina , Ração Animal , Animais , Fenômenos Biomecânicos , Densidade Óssea , Fêmur/anatomia & histologia , Fator de Crescimento Insulin-Like I/metabolismo , Íons , Masculino , Osteocalcina/sangue , Osteoporose/patologia , Ratos , Ratos WistarRESUMO
Hesperidin (Hp), a citrus flavonoid predominantly found in oranges, shows bone-sparing effects in ovariectomised (OVX) animals. In human subjects, the bioavailability of Hp can be improved by the removal of the rhamnose group to yield hesperetin-7-glucoside (H-7-glc). The aim of the present work was to test whether H-7-glc was more bioavailable and therefore more effective than Hp in the prevention of bone loss in the OVX rat. Adult 6-month-old female Wistar rats were sham operated or OVX, then pair fed for 90 d a casein-based diet supplemented or not with freeze-dried orange juice enriched with Hp or H-7-glc at two dose equivalents of the hesperetin aglycone (0.25 and 0.5 %). In the rats fed 0.5 %, a reduction in OVX-induced bone loss was observed regarding total bone mineral density (BMD):+7.0 % in OVX rats treated with Hp (HpOVX) and +6.6 % in OVX rats treated with H-7-glc (H-7-glcOVX) v. OVX controls (P < 0.05). In the rats fed 0.25 % hesperetin equivalents, the H-7-glcOVX group showed a 6.6 % improvement in total femoral BMD v. the OVX controls (P < 0.05), whereas the Hp diet had no effect at this dose. The BMD of rats fed 0.25 % H-7-glc was equal to that of those given 0.5 % Hp, but was not further increased at 0.5 % H-7-glc. Plasma hesperetin levels and relative urinary excretion were significantly enhanced in the H-7-glc v. Hp groups, and the metabolite profile showed the absence of eriodictyol metabolites and increased levels of hesperetin sulphates. Taken together, improved bioavailability of H-7-glc may explain the more efficient bone protection of this compound.