Therapeutic option by synergistic administration of the β-hydroxy-β-methyl butyrate and R(+) Lipoic Acid in a cellular model of dexamethasone-dependent sarcopenia

The decline of muscle mass and strength, known as sarcopenia, is a clinical problem associated with osteo-articular diseases, muscle disuse, cancer, renal failure, postmemenopause, age and corticosteroid treatments [1,2]. In this scenario, alterations in mitochondrial function [3] and accelerated apoptosis in skeletal muscle [4] are considered a major factor underlying sarcopenia and muscle atrophy. These evidences suggests that targeting myonuclear apoptosis as well as reducing the oxidative stress might provide novel and effective therapeutic tools to combat sarcopenia. Alpha-lipoic acid (1,2-dithiolane- 3-pentanoic acid), is a natural antioxidant with two optical isomers of which the (+)- possess a more pronounced effect (R (+) LA) [7]. Beta-hydroxy-beta-methylbutyrate (HMB), a leucine catabolite, has been shown to prevent muscle damage directly enhancing myogenic cells (satellite cells) proliferation and attenuating apoptosis [8]. Aim of the present research was the evaluation of the pharmacological profile of the HMB associated with the natural R(+)LA in a cellular model of muscle wasting. Material and Methods. C2C12 cell line was used as myoblasts or differentiated in miotubes by 7 day culture with 2% horse serum. Cell damage was induced by dexamethasone. Results. Dexamethasone toxicity was evaluated measuring cell viability (MTT assay) and apoptosis induction (caspase 3 activity) after 24h and 48h incubation of myoblasts with the glucocorticoid (0.01–300 μM concentration range). One μM dexamethasone (48h) decreased cell viability by about 50% and increased caspase 3 activity by 80%. R(+)LA (100 and 300 μM) or HMB (1 and 3 mM) significantly prevented dexamethasone-induced cell mortality; the efficacy was improved when 100 μM R(+)LA was combined with 1mM HMB, demonstrating the synergistic effect of R(+)LA and HMB in preventing cell mortality and caspase 3 activation. Similarly, the evaluation of dexamethasone evoked O2-. production and protein carbonylation demonstrated the efficacy of the combination of R(+)LA with HMB. In the early phase of myotube differentiation (72h) the combination of R(+)LA and HMB preserved the number of myogenin-positive cells as well as in the later (7 days) phase of differentiation the dexamethasone-dependent damage (evaluated as cell diameter and percentage of multinucleated cells). These data offer a rational to candidate the mixture as a therapeutic option for sarcopenia treatment

α7 Nicotinic Receptor Promotes the Neuroprotective Functions of Astrocytes against Oxaliplatin Neurotoxicity

Neuropathies are characterized by a complex response of the central nervous system to injuries. Glial cells are recruited to maintain neuronal homeostasis but dysregulated activation leads to pain signaling amplification and reduces the glial neuroprotective power. Recently, we highlighted the property of α7 nicotinic-acetylcholine-receptor (nAChR) agonists to relieve pain and induce neuroprotection simultaneously with a strong increase in astrocyte density. Aimed to study the role of α7 nAChR in the neuron-glia cross-talk, we treated primary rat neurons and astrocytes with the neurotoxic anticancer drug oxaliplatin evaluating the effect of the α7 nAChR agonist PNU-282987 (PNU). Oxaliplatin (1 μM, 48 h) reduced cell viability and increased caspase-3 activity of neuron monocultures without damaging astrocytes. In cocultures, astrocytes were not able to protect neurons by oxaliplatin even if glial cell metabolism was stimulated (pyruvate increase). On the contrary, the coculture incubation with 10 μM PNU improved neuron viability and inhibited apoptosis. In the absence of astrocytes, the protection disappeared. Furthermore, PNU promoted the release of the anti-inflammatory cytokine TGF-β1 and the expression of the glutamate-detoxifying enzyme glutamine synthetase. The α7 nAChR stimulation protects neurons from oxaliplatin toxicity through an astrocyte-mediated mechanism. α7 nAChR is suggested for recovering the homeostatic role of astrocytes

Selenium and zinc: Two key players against cadmium-induced neuronal toxicity

Cadmium (Cd), a worldwide occupational pollutant, is an extremely toxic heavy metal, capable of damaging several organs, including the brain. Its toxicity has been related to neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. The neurotoxic potential of Cd has been attributed to the changes induced in the brain enzyme network involved in counteracting oxidative stress. On the other hand, it is also known that trace elements, such as zinc (Zn) and selenium (Se), required for optimal brain functions, appears to have beneficial effects on the prevention of Cd intoxication. Based on this protective effect of Zn and Se, we aimed to investigate whether these elements could protect neuronal cells from Cd-induced excitotoxicity. The experiments, firstly carried out on SH-SY5Y catecholaminergic neuroblastoma cell line, demonstrated that the treatment with 10 muM cadmium chloride (CdCl2) for 24 h caused significant modifications both in terms of oxidative stress and neuronal sprouting, triggered by endoplasmic reticulum (ER) stress. The evaluation of the effectiveness of 50 muM of zinc chloride (ZnCl2) and 100 nM sodium selenite (Na2SeO3) treatments showed that both elements were able to attenuate the Cd-dependent neurotoxicity. However, considering that following induction with retinoic acid (RA), the neuroblastoma cell line undergoes differentiation into a cholinergic neurons, our second aim was to verify the zinc and selenium efficacy also in this neuronal phenotype. Our data clearly demonstrated that, while zinc played a crucial role on neuroprotection against Cd-induced neurotoxicity independently from the cellular phenotype, selenium is ineffective in differentiated cholinergic cells, supporting the notion that the molecular events occurring in differentiated SH-SY5Y cells are critical for the response to specific stimuli

3‑Hydroxy‑1<i>H</i>‑quinazoline-2,4-dione as a New Scaffold To Develop Potent and Selective Inhibitors of the Tumor-Associated Carbonic Anhydrases IX and XII

In this paper, we describe the discovery of the 3-hydroxyquinazoline-2,4-dione as a useful scaffold to obtain potent inhibitors of the tumor-associated human carbonic anhydrases (hCAs) IX and XII. A set of derivatives (<b>1</b>–<b>29</b>), bearing different substituents on the fused benzo ring (Cl, NO₂, NH₂, CF₃, ureido, amido, heterocycles), were synthesized, and several of them showed nanomolar activity in inhibiting the hCA IX and XII isoforms, while they were ineffective against the cytosolic enzymes hCAs I and II. Some selected compounds were tested for their antiproliferative activity against HT-29 colon cancer cell lines. After 48 h of treatment with the lower dose (30 μM), derivatives <b>12</b>, <b>14</b>, <b>15</b>, and <b>19</b> were significantly active, inducing a mortality by about 50% in both normoxia and hypoxia. This finding led us to hypothesize for these compounds more than one mechanism of action involving both CAs IX and XII and other not yet identified target(s)