Quality-of-life outcomes with a disodium EDTA chelation regimen for coronary disease: results from the trial to assess chelation therapy randomized trial

Chelation Therapy in Patients With Cardiovascular Disease: A Systematic Review

Background EDTA is an intravenous chelating agent with high affinity to divalent cations (lead, cadmium, and calcium) that may be beneficial in the treatment of cardiovascular disease (CVD). Although a large randomized clinical trial showed benefit, smaller studies were inconsistent. We conducted a systematic review of published studies to examine the effect of repeated EDTA on clinical outcomes in adults with CVD. Methods and Results We searched 3 databases (MEDLINE, Embase, and Cochrane) from database inception to October 2021 to identify all studies involving EDTA treatment in patients with CVD. Predetermined outcomes included mortality, disease severity, plasma biomarkers of disease chronicity, and quality of life. Twenty-four studies (4 randomized clinical trials, 15 prospective before/after studies, and 5 retrospective case series) assessed the use of repeated EDTA chelation treatment in patients with preexistent CVD. Of these, 17 studies (1 randomized clinical trial) found improvement in their respective outcomes following EDTA treatment. The largest improvements were observed in studies with high prevalence of participants with diabetes and/or severe occlusive arterial disease. A meta-analysis conducted with 4 studies reporting ankle-brachial index indicated an improvement of 0.08 (95% CI, 0.06-0.09) from baseline. Conclusions Overall, 17 studies suggested improved outcomes, 5 reported no statistically significant effect of treatment, and 2 reported no qualitative benefit. Repeated EDTA for CVD treatment may provide more benefit to patients with diabetes and severe peripheral arterial disease. Differences across infusion regimens, including dosage, solution components, and number of infusions, limit comparisons across studies. Additional research is necessary to confirm these findings and to evaluate the potential mediating role of metals. Registration URL: https://www.crd.york.ac.uk/; Unique identifier: CRD42020166505.

Rescue bisphosphonate treatment of alveolar bone improves extraction socket healing and reduces osteonecrosis in zoledronate-treated mice

Bisphosphonate (BP)-related osteonecrosis of the jaw, previously known as BRONJ, now referred to more broadly as medication-related osteonecrosis of the jaw (MRONJ), is a morbid condition that represents a significant risk for oncology patients who have received high dose intravenous (IV) infusion of a potent nitrogen containing BP (N-BP) drug. At present, no clinical procedure is available to prevent or effectively treat MRONJ. Although the pathophysiological basis is not yet fully understood, legacy adsorbed N-BP in jawbone has been proposed to be associated with BRONJ by one or more mechanisms. We hypothesized that removal of the pre-adsorbed N-BP drug common to these pathological mechanisms from alveolar bone could be an effective preventative/therapeutic strategy. This study demonstrates that fluorescently labeled BP pre-adsorbed on the surface of murine maxillo-cranial bone in vivo can be displaced by subsequent application of other BPs. We previously described rodent BRONJ models involving the combination of N-BP treatment such as zoledronate (ZOL) and dental initiating factors such as tooth extraction. We further refined our mouse model by using gel food during the first 7 days of the tooth extraction wound healing period, which decreased confounding food pellet impaction problems in the open boney socket. This refined mouse model does not manifest BRONJ-like severe jawbone exposure, but development of osteonecrosis around the extraction socket and chronic gingival inflammation are clearly exhibited. In this study, we examined the effect of benign BP displacement of legacy N-BP on tooth extraction wound healing in the in vivo model. Systemic IV administration of a low potency BP (lpBP: defined as inactive at 100 μM in a standard protein anti-prenylation assay) did not significantly attenuate jawbone osteonecrosis. We then developed an intra-oral formulation of lpBP, which when injected into the gingiva adjacent to the tooth prior to extraction, dramatically reduced the osteocyte necrosis area. Furthermore, the tooth extraction wound healing pattern was normalized, as evidenced by timely closure of oral soft tissue without epithelial hyperplasia, significantly reduced gingival inflammation and increased new bone filling in the extraction socket. Our results are consistent with the hypothesis that local application of a rescue BP prior to dental surgery can decrease the amount of a legacy N-BP drug in proximate jawbone surfaces below the threshold that promotes osteocyte necrosis. This observation should provide a conceptual basis for a novel strategy to improve socket healing in patients treated with BPs while preserving therapeutic benefit from anti-resorptive N-BP drug in vertebral and appendicular bones.

Effect of Selected Plant Phenolics on Fe2+-EDTA-H₂O₂ System Mediated Deoxyribose Oxidation: Molecular Structure-Derived Relationships of Anti- and Pro-Oxidant Actions

In the presence of transition metal ions and peroxides, polyphenols, well-known dietary antioxidants, can act as pro-oxidants. We investigated the effect of 13 polyphenols and their metabolites on oxidative degradation of deoxyribose by an ^•OH generating Fenton system (Fe²⁺-ethylenediaminetetraacetic acid (EDTA)-H₂O₂). The relationship between phenolics pro-oxidant/anti-oxidant effects and their molecular structure was analyzed using multivariate analysis with multiple linear regression and a backward stepwise technique. Four phenolics revealed a significant inhibitory effect on OH-induced deoxyribose degradation, ranging from 54.4% ± 28.6% (3,4-dihydroxycinnamic acid) to 38.5% ± 10.4% (catechin) (n = 6), correlating with the number of –OH substitutions (r = 0.58). Seven phenolics augmented the oxidative degradation of deoxyribose with the highest enhancement at 95.0% ± 21.3% (quercetin) and 60.6% ± 12.2% (phloridzin). The pro-oxidant effect correlated (p < 0.05) with the number of –OH groups (r = 0.59), and aliphatic substitutes (r = −0.22) and weakly correlated with the occurrence of a catechol structure within the compound molecule (r = 0.17). Selective dietary supplementation with phenolics exhibiting pro-oxidant activity may increase the possibility of systemic oxidative stress in patients treated with medications containing chelating properties or those with high plasma concentrations of H₂O₂ and non-transferrin bound iron.