Facultad de Ciencias de la Salud

Aim: Sodium-glucose co-transporter 2 inhibitors and mineralocorticoid receptor antagonists reduce albuminuria and the risk of kidney failure. The aim of this study was to investigate the effects of both agents alone and in combination on markers of the glomerular endothelial glycocalyx and tubular function. Methods: This post-hoc analysis utilized data of the ROTATE-3 study, a randomized cross-over study in 46 adults with chronic kidney disease and urinary albumin excretion ≥100 mg/24 h, who were treated for 4 weeks with dapagliflozin, eplerenone or its combination. The effects of dapagliflozin, eplerenone and the combination on outcome measures such as heparan sulphate, neuro-hormonal markers and tubular sodium handling were assessed with mixed repeated measures models. Results: The mean percentage change from baseline in heparan sulphate after 4 weeks treatment with dapagliflozin, eplerenone or dapagliflozin-eplerenone was -34.8% (95% CI -52.2, -10.9), -5.9% (95% CI -32.5, 31.3) and -28.1% (95% CI -48.4, 0.1) respectively. The mean percentage change from baseline in plasma aldosterone was larger with eplerenone [38.9% (95% CI 2.8, 87.7)] and dapagliflozin-eplerenone [32.2% (95% CI -1.5, 77.4)], compared with dapagliflozin [-12.5% (95% CI -35.0, 17.8)], respectively. Mean percentage change from baseline in copeptin with dapagliflozin, eplerenone or dapagliflozin-eplerenone was 28.4% (95% CI 10.7, 49.0), 4.2% (95% CI -10.6, 21.4) and 23.8% (95% CI 6.6, 43.9) respectively. Dapagliflozin decreased proximal absolute sodium reabsorption rate by 455.9 mmol/min (95% CI -879.2, -32.6), while eplerenone decreased distal absolute sodium reabsorption rate by 523.1 mmol/min (95% CI -926.1, -120.0). Dapagliflozin-eplerenone decreased proximal absolute sodium reabsorption [-971.0 mmol/min (95% CI -1411.0, -531.0)], but did not affect distal absolute sodium reabsorption [-9.2 mmol/min (95% CI -402.0, 383.6)]. Conclusions: Dapagliflozin and eplerenone exert different effects on markers of glomerular and tubular function supporting the hypothesis that different mechanistic pathways may account for their kidney protective effects.

Objective. Only a few studies assessing the sleep effects of low doses of melatonin (aMT) have been performed in the past, most of them in adults, and only one in subjects with attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to provide evidence of the changes induced by aMT doses as low as 1 mg in the sleep pattern of pediatric patients with ADHD under treatment with methylphenidate (MPH). Methods. Children and adolescents (7–15 years) with ADHD who were receiving extended-release MPH were recruited. A seven-week sleep diary was collected prior to starting a four-week treatment with 1 mg of aMT (30 min before bedtime). Seven-day actigraphic assessments of sleep were performed before and after treatment. Results. Twenty-seven patients (17 males, 62.96%) participated in the study, who had been receiving MPH for 1.57 (1.11) months. A significant increase in sleep duration (TST) was observed after one month of treatment (463 (49) min to 485 (41) min; p < 0.040), with nonsignificant improvements in sleep-onset latency (SOL), nocturnal awakenings, or sleep efficiency. Only minor adverse effects were reported. Conclusion. Low doses of melatonin (1 mg) are able to increase TST in children and adolescents with ADHD receiving treatment with psychostimulants, with an adequate tolerability profile. Further placebo-controlled trials adjusting the time of aMT administration to the individual circadian profile should explore the effects of low doses of this hormone to shorten SOL in this population of patients.

Background: Sodium glucose cotransporter 2 (SGLT2) inhibitors and mineralocorticoid receptor antagonists (MRAs) reduce the urinary albumin-to-creatinine ratio (UACR) and confer kidney and cardiovascular protection in patients with CKD. We assessed efficacy and safety of the SGLT2 inhibitor dapagliflozin and MRA eplerenone alone and in combination in patients with CKD. Methods: We conducted a randomized open-label crossover trial in patients with urinary albumin excretion ≥100 mg/24 hr, eGFR 30-90 ml/min per 1.73 m2, who had been receiving maximum tolerated stable doses of an ACE inhibitor (ACEi) or angiotensin receptor blocker (ARB). Patients were assigned to 4-week treatment periods with dapagliflozin 10 mg/day, eplerenone 50 mg/day, or their combination in random order, separated by 4-week washout periods. Primary outcome was the correlation in UACR changes between treatments. Secondary outcome was the percent change in 24-hour UACR from baseline. Results: Of 57 patients screened, 46 were randomly assigned (mean eGFR, 58.1 ml/min per 1.73 m2; median UACR, 401 mg/g) to the three groups. Mean percentage change from baseline in UACR after 4 weeks of treatment with dapagliflozin, eplerenone, and dapagliflozin-eplerenone was -19.6% (95% confidence interval [CI], -34.3 to -1.5), -33.7% (95% CI, -46.1 to -18.5), and -53% (95% CI, -61.7 to -42.4; P<0.001 versus dapagliflozin; P=0.01 versus eplerenone). UACR change during dapagliflozin or eplerenone treatment did not correlate with UACR change during dapagliflozin-eplerenone (r=-0.13; P=0.47; r=-0.08; P=0.66, respectively). Hyperkalemia was more frequently reported with eplerenone (n=8; 17.4%) compared with dapagliflozin (n=0; 0%) or dapagliflozin-eplerenone (n=2; 4.3%; P between-groups=0.003). Conclusions: Albuminuria changes in response to dapagliflozin and eplerenone did not correlate, supporting systematic rotation of these therapies to optimize treatment. Combining dapagliflozin with eplerenone resulted in a robust additive UACR-lowering effect. A larger trial in this population is required to confirm long-term efficacy and safety of combined SGLT2 inhibitor and MRA treatment.

The progressive emergence of antimicrobial resistance has become a global health problem in need of rapid solution. Research into new antimicrobial drugs is imperative. Drug repositioning, together with computational mathematical prediction models, could be a fast and efficient method of searching for new antibiotics. The aim of this study was to identify compounds with potential antimicrobial capacity against Escherichia coli from US Food and Drug Administration-approved drugs, and the similarity between known drug targets and E. coli proteins using a topological structure-activity data analysis model. This model has been shown to identify molecules with known antibiotic capacity, such as carbapenems and cephalosporins, as well as new molecules that could act as antimicrobials. Topological similarities were also found between E. coli proteins and proteins from different bacterial species such as Mycobacterium tuberculosis, Pseudomonas aeruginosa and Salmonella Typhimurium, which could imply that the selected molecules have a broader spectrum than expected. These molecules include antitumor drugs, antihistamines, lipid-lowering agents, hypoglycemic agents, antidepressants, nucleotides, and nucleosides, among others. The results presented in this study prove the ability of computational mathematical prediction models to predict molecules with potential antimicrobial capacity and/or possible new pharmacological targets of interest in the design of new antibiotics and in the better understanding of antimicrobial resistance.

Fluorimetric analysis is still a growing line of research in the determination of a wide range of organic compounds, including pharmaceuticals and pesticides, which makes necessary the development of new strategies aimed at improving the performance of fluorescence determinations as well as the sensitivity and, especially, the selectivity of the newly developed analytical methods. In this paper are presented applications of a useful and growing tool suitable for fostering and improving research in the analytical field. Experimental screening, molecular connectivity and discriminant analysis are applied to organic compounds to predict their fluorescent behaviour after their photodegradation by UV irradiation in a continuous flow manifold (multicommutation flow assembly). The screening was based on online fluorimetric measurement and comprised pre-selected compounds with different molecular structures (pharmaceuticals and some pesticides with known 'native' fluorescent behaviour) to study their changes in fluorescent behaviour after UV irradiation. Theoretical predictions agree with the results from the experimental screening and could be used to develop selective analytical methods, as well as helping to reduce the need for expensive, time-consuming and trial-and-error screening procedures.

Metal complexes have gained a huge interest in the biomedical research in the last decade because of the access to unexplored chemical space with regards to organic molecules and to present additional functionalities to act simultaneously as diagnostic and therapeutic agents. Herein, we evaluated the interaction of two polytopic polyaza ligands and their zinc complexes with DNA and RNA by UV thermal denaturation, fluorescence and circular dichroism spectroscopic assays. The zinc coordination was investigated by X-ray diffraction and afforded the structure of the binuclear zinc complex of PYPOD. Thermal denaturation of DNA and RNA and fluorimetry analysis revealed preferential binding of the zinc-PHENPOD complexes towards GC-containing DNA in contrast to the free ligands. On the other hand, PYPOD metal complexes, compared to the free ligand, stabilized AT-based DNA (B-form) better than AU-RNA (A-form). With regards to single stranded RNA, the binuclear complex of PHENPOD and the free ligand can efficiently identify polyadenylic acid (poly A) among other RNA sequences by circular dichroism spectroscopy. The antimicrobial activity in S. aureus and E. coli bacteria showed the highest activity for the free ligands and their trinuclear zinc complexes. This work can provide valuable insights into the impact of the nuclearity of polytopic polyaza ligands in the binding to DNA/RNA and the antimicrobial effect.

The objective of this research was to develop and evaluate an ocular insert for the controlled drug delivery of moxifloxacin which could perhaps be used in the treatment of corneal keratitis or even bacterial endophthalmitis. We have evaluated the ex vivo ocular diffusion of moxifloxacin through rabbit cornea, both fresh and preserved under different conditions. Histological studies were also carried out. Subsequently, drug matrix inserts were prepared using bioadhesive polymers. The inserts were evaluated for their physicochemical parameters. Ophthalmic ex vivo permeation of moxifloxacin was carried out with the most promising insert. The formulate insert was thin and provided higher ocular diffusion than commercial formulations. Ocular diffusion studies revealed significant differences between fresh and frozen corneas. Histological examinations also showed differences in the thickness of stroma between fresh and frozen corneas. The ophthalmic insert we have developed allows a larger quantity of moxifloxacin to permeate through the cornea than existing commercial formulations of the drug. Ocular delivery of moxifloxacin with this insert could be a new approach for the treatment of eye diseases.

Progesterone (PG) has been shown to have a slowing effect on photoreceptor cell death in mouse models of retinitis pigmentosa when administered orally. The aim of this study was to investigate whether ophthalmically administered progesterone was able to reach neuroretina and thus, the distribution through ocular tissues of different PG formulations was studied. The effect of different initial PG concentration was also investigated. Different formulations with PG in their composition (drops, a corneal/scleral-insert and scleral-inserts) were prepared and assayed. Using whole porcine eyes, the different formulations were topically administered to the ocular surface. Frozen eyes were dissected, the PG in each tissue was extracted in acetonitrile and the amount of PG quantified by UHPLC-MS/MS. Our results show that after topical administration, PG diffuses from the ocular surface and distributes throughout all tissues of the eye. Lower levels of PG were found in sclera, choroid and neuroretina when PG was applied as drops compared to inserts. Our results also show that an increase in the initial PG concentrations applied, resulted in a statistically significant increase in the amounts of PG in aqueous humour, sclera, choroid and neuroretina.

Leishmaniasis, African sleeping sickness and Chagas disease, caused by the kinetoplastid parasites Leishmania spp, Trypanosoma brucei and Trypanosoma cruzi, respectively, are among the most important parasitic diseases, affecting millions of people and considered to be within the most relevant group of neglected tropical diseases. The main alternative to control such parasitosis is chemotherapy. Nevertheless, the current chemotherapeutic treatments are far from being satisfactory. This review outlines the current understanding of different drugs against leishmaniasis, African sleeping sickness and Chagas disease, their mechanism of action and resistance. Recent approaches in the area of anti-leishmanial and trypanocidal therapies are also enumerated, new modulators from the mode of action, development of new formulations of old drugs, therapeutic switching and “in silico” drug design.

A series of compounds containing the nitrobenzene and sulfonamido moieties were synthesized and their leishmanicidal effect was assessed in vitro against Leishmania infantum promastigotes. Among the compounds evaluated, the p-nitrobenzenesulfonamides 4Aa and 4Ba, and the p-nitroaniline 5 showed significant activity with a good selectivity index. In a Balb/c mice model of L. Infantum, administration of compounds 4Aa, 4Ba or 5 (5 mg/kg/day for 10 days, injected ip route) led to a clear-cut parasite burden reduction (ca. 99%). In an attempt to elucidate their mechanism of action, the DNA interaction of 4Aa and 5 was investigated by means of viscosity studies, thermal denaturation and nuclease activity assay. Both compounds showed nuclease activity in the presence of copper salt. The results suggest that compounds 4Aa, 4Ba and 5 represent possible candidates for drug development in the therapeutic control of leishmaniasis.