Boron is considered to be a biological trace element but there is substantial and growing support for it to be classified as an essential nutrient for animals and humans, depending on its speciation. Boron-containing compounds have been reported to play an important role in biological systems. Although the exact biochemical functions of boron-containing compounds have not yet been fully elucidated, previous studies suggest an active involvement of these molecules in the mediation of inflammation and oxidative stress. Chronic inflammation and oxidative stress are known to amplify the effects of the main cardiovascular risk factors: smoking, diet, obesity, arterial hypertension, dyslipidemia, type 2 diabetes (as modifiable risk factors), and hyperhomocysteinemia and age (as independent risk factors). However, the role of boron-containing compounds in cardiovascular systems and disease prevention has yet to be established. This paper is a review of boron-containing compounds' existence in nature and their possible functions in living organisms, with a special focus on certain cardiovascular risk factors that may be diminished by intake of these compounds, leading to a reduction of cardiovascular morbidity and/or mortality.

Sugar–borates (SBs) are mono- or di-sugar–borate esters (SBEs) comprised of one or two monosaccharide molecules linked to a boron (B) atom. SBEs occur naturally in commonly consumed herbs, vegetables, fruits, seeds, and nuts and, other than greatly varying levels of B found in local drinking water, are the primary natural dietary sources of B-containing molecules in humans. To date, the most studied SBE is calcium fructoborate (CaFB). CaFB represents an important example of how organic B-containing molecules are significantly distinct from their inorganic counterparts. During these past two decades, CaFB has been researched for its physical and biochemical characteristics, safety, and clinical outcomes. Results of these researches are presented and discussed herein. CaFB has been characterized using Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), high-performance thin-layer chromatography (HPTLC), nuclear magnetic resonance (NMR), liquid chromatography–multistage accurate mass spectrometry (LC-MSn), X-ray diffraction (XRD), Raman spectroscopy, and inductively coupled plasma (ICP) in non-biological and biological specimens. Potential health benefits of CaFB have been clinically investigated in pilot and efficacy studies demonstrating (i) significant reductions in knee discomfort and improved flexibility within 7, 14, and 90 days and (ii) significant effect on blood levels of inflammatory, cardiovascular, and other biomarkers. These studies support the use of CaFB as a dietary supplement for the management of joint discomfort. CaFB is presented here in order to illustrate how physiological benefits are imparted by distinct organic boron-containing molecules rather than solely by the element B itself. Considering recent National Health and Nutrition Examination Survey (NHANES) data reporting increases in age-related joint pain and an increasing elderly demographic, SBEs offer potential for safe, natural, and effective management of joint discomfort and improved mobility in human and animal health applications. Several of these studies may also open new opportunities for use of SBEs for health benefits beyond joint health.

In this work, an improved version of the radio frequency magnetron sputtering (RF-MS) technique was used to prepare highly adherent B-type carbonated hydroxylapatite (B-CHA) thin films. Fourier transform infrared spectroscopy (FTIR) and grazing incidence X-ray diffraction studies proved that the coatings maintained the composition and revealed the polycrystalline structure of HA. Scanning electron microscopy analysis showed that the CHA films are rough and exhibit a homogeneous microstructure. Energy-dispersive X-ray spectroscopy (EDX) mapping demonstrated a uniform distribution of the Ca and P cations while a Ca/P ratio of 1.8 was found. In addition, the FTIR experiments showed a remarkable reproducibility of the nanostructures. Human mesenchymal stem cells (hMSCs), in vitro differentiated osteoblasts, and explanted bone cells were grown over the surface of CHA coatings for periods between a few hours and 21 days. Osteoprogenitor cells maintained viability and characteristic morphology after adhesion on CHA coatings. Ki67-positive osteoblasts were the evidence of cell proliferation events. Cells showed positive staining for markers of osteoblast phenotype such as collagen type I, bone sialoprotein and osteonectin. Our data showed the formation of mineralized foci by differentiation of hMSCs to human primary osteoblasts after cultivation in osteogenic media on RF-sputtered films. The results demonstrate the capacity of B-type CHA coating to support MSCs adhesion and osteogenic differentiation ability.

Calcium fructoborate (CFB) has been reported as supporting healthy inflammatory response. In this study, we assess the effects of CFB on blood parameters and proinflammatory cytokines in healthy subjects. This was a randomized, double-blinded, placebo-controlled trial. Participants received placebo or CFB at a dose of 112 mg/day (CFB-1) or 56 mg/day (CFB-2) for 30 days. Glucose, total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), C-reactive protein (CRP), homocysteine, interleukin 1 beta (IL-1β), IL-6, and monocyte chemoattractant protein-1 (MCP-1) were determined before and after supplementation. CFB-1 showed a reduction in blood levels of CRP by 31.3 % compared to baseline. CFB-1 and CFB-2 reduced LDL levels by 9.8 and 9.4 %, respectively. CFB-1 decreased blood homocysteine by 5.5 % compared with baseline, whereas CFB-2 did not have a significant effect. Blood levels of TG were reduced by 9.1 and 8.8 % for CFB-1 and CFB-2, respectively. Use of both CFB-1 and CFB-2 resulted in significantly reduced IL-6 levels, when compared within and between groups. IL-1β was reduced by 29.2 % in the CFB-1 group. Finally, CFB-1 and CFB-2 reduced MCP-1 by 31 and 26 %, respectively. Our data indicate that 30-day supplementation with 112 mg/day CFB (CFB-1) resulted in a significant reduction of LDL, TG, TC, IL-1β, IL-6, MCP-1, and CRP. HDL levels were increased, when compared to baseline and placebo. These results suggest that CFB might provide beneficial support to healthy cardiovascular systems by positively affecting these blood markers (ClinicalTrials.gov, ISRCTN90543844; May 24, 2012 (http://www.controlled-trials.com/ISRCTN90543844)).

Calcium fructoborate (CF), a natural sugar-borate ester found in fresh fruits and vegetables, is a source of soluble boron. CF contains three forms of borate (diester, monoester, and boric acid) and all are biologically active, both at the intracellular (as free boric acid) and extracellular level (as fructose-borate diester and monoester). At the cellular and molecular level, CF is superior to the boric acid/borate, exhibiting a complex “protective” effect against inflammatory response. CF is commercially available in the USA as a “nature-identical” complex, an active compound for dietary supplements. It provides effective and safe support against the discomfort and lack of flexibility associated with osteoarticular conditions (arthritis and joint degeneration), and improves Western Ontario and McMaster Universities Osteoarthritis (WOMAC) and McGill indexes. In addition, orally administered CF is effective in ameliorating symptoms of physiological response to stress, including inflammation of the mucous membranes, discomfort associated with osteoarthritis disorders, and bone loss, and also for supporting cardiovascular health. Clinical studies have exhibited the ability of CF to significantly modulate molecular markers associated with inflammatory mechanisms, mainly on the elevated serum levels of C-reactive protein (CRP).