Association between low bone mass and calcium and caffeine intake among perimenopausal women in Southern Brazil: cross-sectional study

Probiotics and Isoflavones as a Promising Therapeutic for Calcium Status and Bone Health: A Narrative Review

Probiotics have potential clinical effects for treating and preventing osteoporosis. Meanwhile, isoflavones have attracted much attention due to their ability to prevent postmenopausal symptoms. Research has established that probiotics and isoflavones can regulate hormones, immune cells, and the gastrointestinal system, acting as links in the gut-bone axis. However, combining the effects of probiotics and isoflavones on calcium status and bone health is a more novel and a still-evolving research area. Lactobacillus and Bifidobacterium are the foremost strains that influence bone health to a significant extent. Among the isoflavones, daidzein, genistein, and the metabolites of genistein (such as equol) stimulate bone formation. It can be concluded that probiotics and isoflavones promote bone health by regulating calcium uptake, gut microbiota, and various metabolic pathways that are associated with osteoblast activity and bone formation. Nevertheless, further experiments of probiotics and isoflavones are still necessary to confirm the association between calcium bioavailability and bone health.

Psoralidin prevents caffeine-induced damage and abnormal differentiation of bone marrow mesenchymal stem cells via the classical estrogen receptor pathway

Background

Caffeine is broadly present in tea, coffee, and cocoa, and is commonly consumed. The bone microenvironment might be damaged by excessive caffeine, which has been shown to exert negative effects on human health. In this study, we sought to determine whether excessive caffeine could damage the biological functions of bone marrow mesenchymal stem cells (BMSCs) and induce bone loss in mice, and further investigate effective therapeutic methods.

Methods

BMSCs were treated with different concentrations of caffeine (0.01, 0.05, 0.1, 0.5, and 1.0 mM) for 48 h. Cell counting kit-8 (CCK-8) assay, colony formation assay, wound healing assay, and quantitative real-time polymerase chain reaction (qRT-PCR) analysis were performed to detect the cell viability, proliferation, migration, and pluripotency of BMSCs, respectively. Alizarin red S (ARS) staining, alkaline phosphatase (ALP) staining, oil red O (ORO) staining, and qRT-PCR assay were applied to assess the osteogenic and adipogenic differentiation of BMSCs. BMSCs were treated with caffeine and further exposed to different concentrations of psoralidin (PL) (0.01, 0.1, 1, and 10 µM) for 48 h. Micro-computed tomography (µCT) scanning was used to evaluate the bone mass of mice. 7α-(7-((4,4,5,5,5-Pentafluoropentyl)-sulfiny)nonyl)estra-1,3,5(10)-triene-3,17β-diol (ICI 182,780, ICI) was applied to examine whether the classical estrogen receptor (ER) pathway was involved.

Results

The CCK-8 assay, colony formation assay, wound healing assay, and qRT-PCR analysis indicated that caffeine (0.01, 0.05, 0.1, 0.5, 1.0 mM) attenuated the cell viability, proliferation, migration and pluripotency of BMSCs, respectively, in a concentration-dependent manner. Caffeine treatment inhibited osteogenic differentiation but promoted adipogenic differentiation of BMSCs in a dose-dependent manner. Furthermore, ARS staining, ALP staining, ORO staining, and qRT-PCR assay showed that excessive caffeine induced bone loss and osteoporosis (OP) in mice by regulating the osteogenesis and adipogenesis of BMSCs. Also, PL treatment could reverse the caffeine-induced dysfunctions and aberrant differentiation of BMSCs via the ER pathway.

Conclusions

Our results revealed a novel molecular mechanism for the therapeutic effects of PL in treating excessive caffeine-induced OP, which might shed new light on the clinical application of PL for caffeine-related OP.

The Effect of Caffeine on Calcitriol-Inducible Vitamin D Receptor-Controlled Gene Expression in Intestinal and Osteoblastic Cells

Some epidemiological studies suggested caffeine consumption as the cause for bone mineral density loss. Certain genes involved in this process are regulated by vitamin D receptor (VDR). Therefore, we investigated if caffeine can affect inducible expression of VDR-regulated genes, some of them being involved in bone mineralization process. By employing reporter gene assay, polymerase chain reaction, and western blotting, we monitored the VDR activity and expression in cell cultures of intestinal (LS180), osteosarcoma (HOS), and normal human osteoblasts in vitro. While caffeine stimulated calcitriol-inducible VDR-dependent nanoluciferase activity in stable reporter cell line IZ-VDRE (derived from LS180), it rather modulated mRNA levels of target genes, like CYP24A1, BGLAP, SPP1, and TNSF11 in LS180 and HOS cells. However, caffeine significantly decreased calcitriol-inducible CYP24A1, TNSF11, and SPP1 transcripts in osteoblasts. This decrease had non-linear U-shaped profile. Our in vitro data demonstrate biphasic action of caffeine on the expression of certain calcitriol-inducible VDR-regulated genes in normal human osteoblasts.

Caffeine Consumption through Coffee: Content in the Beverage, Metabolism, Health Benefits and Risks

Caffeine (1,3,7-trimethylxanthine) is the most consumed psychoactive substance in the world, acting by means of antagonism to adenosine receptors, mainly A1 and A2A. Coffee is the main natural source of the alkaloid which is quite soluble and well extracted during the brew’s preparation. After consumption, caffeine is almost completely absorbed and extensively metabolized in the liver by phase I (cytochrome P450) enzymes, mainly CYP1A2, which appears to be polymorphically distributed in human populations. Paraxanthine is the major caffeine metabolite in plasma, while methylated xanthines and methyluric acids are the main metabolites excreted in urine. In addition to stimulating the central nervous system, caffeine exerts positive effects in the body, often in association with other substances, contributing to prevention of several chronic diseases. The potential adverse effects of caffeine have also been extensively studied in animal species and in humans. These aspects will be approached in the present review.

Calcium and dairy products consumption and association with total hip bone mineral density in women from kosovo

Background and objective:

There is paucity of evidence in southeastern Europe and Kosovo regarding dairy products consumption and association with bone mineral density (BMD). Therefore, the objective of present study was to assess calcium intake and dairy products consumption and to investigate relationship with total hip BMD in a Kosovo women sample.

Methods:

This cross-sectional study included a sample of 185 women divided into respective groups according to total hip BMD. All the study participants completed a food frequency questionnaire and underwent dual-energy X-ray absorptiometry (DEXA) to estimate BMD. Nonparametric tests were performed to compare characteristics of the groups.

Results:

The average dietary calcium intake was 818.41 mg/day. Only 16.75% of the subjects met calcium recommended dietary reference intakes (DRIs). There were no significant differences between low BMD group and normal BMD group regarding average dietary calcium intake, but it was significantly higher in BMDT3 subgroup than in BMDT2 and BMDT1 subgroups.

Conclusions:

The results of this study demonstrate significant relationship of daily dietary calcium intake with upper BMD tertile. Further initiatives are warranted from this study to highlight the importance of nutrition education.