The effect of lithium tetraborate as a novel cardioprotective agent after renal ischemia-reperfusion injury

Abstract Epidemiological studies suggest that acute kidney injury has certain effect on myocardial function. In this study, for the first time, we tested a boron compound namely lithium tetraborate an act as an anti-oxidant and anti-inflammatory agent in ischemia-reperfusion injury. For this, we employed an in vivo rat model with kidney ischemia reperfusion injury to evaluate cardiac injury to clarify the mechanisms of lithium tetraborate. The evaluation of cardiac injury through kidney artery occlusion and reperfusion rat model indicated that lithium tetraborate could (1) reduce oxidative stress-induced endothelial dysfunction; (2) attenuate the inflammatory response of cardiac cells; and (3) alleviate the apoptosis and necrosis of myocytes. In summary, lithium tetraborate demonstrates significant therapeutic properties that contribute to the amelioration of cardiac damage, and it could be a promising candidate for future applications in myocardial dysfunction.

Assessment of chemical purity of 10B-enriched p-boronophenylalanine by high-performance liquid chromatography coupled on-line with inductively coupled plasma optical emission spectrometry.

A dual-detection technique, consisting of a combination of reversed-phase high-performance liquid chromatography and on-line detection of elemental boron in the column effluents by inductively coupled plasma optical emission spectrometry, was tested for drug analysis. The method was applied to assessing the chemical purity of p-boronophenylalanine (BPA), isotopically enriched in 10B. This compound is employed as a fructose complex solution for biodistribution studies in laboratory and clinical trials of boron neutron capture therapy. Besides the determination of the content of BPA, required for chemical quality controls of solutions of the complex used for infusions, resolution of mixtures of BPA and two usually accompanying residual impurities (phenylalanine and tyrosine) was achieved with UV detection. The limits of detection (in solution) were 1.5 and 0.6 ng ml-1, respectively. In addition, by monitoring a sensitive-element emission wavelength it was possible to jointly observe the elution of boron-containing compounds that may be transparent to UV radiation or to confirm the presence of boron in potential impurities accompanying the drug. Those impurities may arise from the BPA synthesis or may be produced by degradation during the aging of the solutions. Chromatographic peaks corresponding to the amino acids and also to a related inorganic compound were detected in BPA-fructose complex solutions that were stored for different times and under different conditions. An increase in the areas of the peaks attributed to tyrosine and phenylalanine was observed for BPA-fructose solutions stored refrigerated for 1 month to 1 year, suggesting that degradation processes able to reduce the amount of bioavailable BPA could be active.

Evaluation of boron removal from water by hydrotalcite-like compounds.

Layered double hydroxides (LDHs) or hydrotalcite (HT)-like compounds with different kinds of metal ions (Mg-Al and Mg-Fe) in the brucite-like sheets were prepared and their adsorption properties were studied in the boron removal from aqueous solution under laboratory conditions. The hydrotalcites were synthesized by the coprecipitation method and were characterized by chemical analyses, X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR) and specific surface area measurements (BET). The affinity of these materials with a mixture of B(OH)(3) and B(OH)(4)(-) was studied as a function of contact time, initial pH of the solutions, HT quantity and B concentration (adsorption isotherms). It was found that 120 min is enough time for the equilibrium state to be reached in boron adsorption. Boron removal was independent of the initial pH of the solutions because of the high buffering capacity of the LDHs. On the other hand, the adsorption capacity increases with increasing the adsorbent quantity. The adsorption isotherms, described by the Langmuir model, are of L-type, suggesting that B(OH)(4)(-) is adsorbed preferentially on HT-like materials. Besides, Mg-Al hydrotalcites showed higher adsorption capacity than Mg-Fe. We proposed that in Mg-Al hydrotalcites, the boron removal occurs by both adsorption on external surface and ion exchange, whereas for Mg-Fe it occurs only by surface adsorption. After treatment of a solution containing 5.2 mgBl(-1) with Mg-Al hydrotalcites the final boron concentration reached the recommended limit by WHO for drinking water (0.5 mgl(-1)).