Neuroprotective properties of exosomes and chitosan nanoparticles of Tomafran, a bioengineered tomato enriched in crocins.

Saffron has many pharmacological properties in addition to being a frequently used food seasoning. Crocin and picrocrocin which accumulate in saffron stigma, are responsible for these pharmacological properties. These natural products have health-promoting effects for the prevention and treatment of numerous diseases, including age-related cognitive and memory disfunction. Currently, crocin and picrocrocin are obtained from saffron, considered as the spice with the highest price in the market. To develop an efficient and low-cost approach to producing these compounds with high bioactivity, biosynthetic genes isolated from saffron can be exploited in the metabolic engineering of heterologous hosts and the production of crocins in productive crop plants. Recently, we engineered tomato fruit producing crocins (Tomafran). In this study, we demonstrated that crocin-rich extract, encapsulated in chitosan or in exosomes may function as a neuroprotective strategy. Crocins contained in the Tomafran extracts and much lower doses in chitosan nanoparticles or exosomes were enough to rescue the neuroblastoma cell line SH-SY5Y after damage caused by okadaic acid. Our results confirm the neuroprotective effect of Tomafran and its exosomes that may be useful for the delay or prevention of neurodegenerative disorders such as Alzheimer's disease.

Preparation of Selenium-Based Drug-Modified Polymeric Ligand-Functionalised Fe3O4 Nanoparticles as Multimodal Drug Carrier and Magnetic Hyperthermia Inductor.

In recent years, much effort has been invested into developing multifunctional drug delivery systems to overcome the drawbacks of conventional carriers. Magnetic nanoparticles are not generally used as carriers but can be functionalised with several different biomolecules and their size can be tailored to present a hyperthermia response, allowing for the design of multifunctional systems which can be active in therapies. In this work, we have designed a drug carrier nanosystem based on Fe3O4 nanoparticles with large heating power and 4-amino-2-pentylselenoquinazoline as an attached drug that exhibits oxidative properties and high selectivity against a variety of cancer malignant cells. For this propose, two samples composed of homogeneous Fe3O4 nanoparticles (NPs) with different sizes, shapes, and magnetic properties have been synthesised and characterised. The surface modification of the prepared Fe3O4 nanoparticles has been developed using copolymers composed of poly(ethylene-alt-maleic anhydride), dodecylamine, polyethylene glycol and the drug 4-amino-2-pentylselenoquinazoline. The obtained nanosystems were properly characterised. Their in vitro efficacy in colon cancer cells and as magnetic hyperthermia inductors was analysed, thereby leaving the door open for their potential application as multimodal agents.

Oral Efficacy of a Diselenide Compound Loaded in Nanostructured Lipid Carriers in a Murine Model of Visceral Leishmaniasis.

Leishmaniasis urgently needs new oral treatments, as it is one of the most important neglected tropical diseases that affects people with poor resources. The drug discovery pipeline for oral administration currently discards entities with poor aqueous solubility and permeability (class IV compounds in the Biopharmaceutical Classification System, BCS) such as the diselenide 2m, a trypanothione reductase (TR) inhibitor. This work was assisted by glyceryl palmitostearate and diethylene glycol monoethyl ether-based nanostructured lipid carriers (NLC) to render 2m bioavailable and effective after its oral administration. The loading of 2m in NLC drastically enhanced its intestinal permeability and provided plasmatic levels higher than its effective concentration (IC50). In L. infantum-infected BALB/c mice, 2m-NLC reduced the parasite burden in the spleen, liver, and bone marrow by at least 95% after 5 doses, demonstrating similar efficacy as intravenous Fungizone. Overall, compound 2m and its formulation merit further investigation as an oral treatment for visceral leishmaniasis.

New Phosphoramidates Containing Selenium as Leishmanicidal Agents.

This work reports the synthesis and characterization by Fourier transform infrared spectroscopy (FTIR), 1H, 13C, and 79Se nuclear magnetic resonance (NMR), mass spectrometry, and elemental analysis techniques as well as the in vitro evaluation of the leishmanicidal activity of 13 new selenophosphoramidate derivatives. Among the new compounds, four of them (compounds 1f, 1g, 2f, and 2g), which exhibited the best profiles, were tested against infected macrophages and were selected for further studies related to their leishmanicidal mechanism. In this regard, trypanothione redox system alteration was determined. Compound 1g, under similar conditions, was more effective than the corresponding references. In addition, theoretical calculations showed that this compound also presents most physicochemical and pharmacokinetic properties within the ranges expected for orally available drugs. It is believed that selenophosphoramidate functionalities may represent a scaffold to be explored toward the development of new agents for leishmania treatment.

Tumor Secretome to Adoptive Cellular Immunotherapy: Reduce Me Before I Make You My Partner.

Adoptive cellular immunotherapy using chimeric antigen receptor (CAR)-modified T cells and Natural Killer (NK) cells are common immune cell sources administered to treat cancer patients. In detail, whereas CAR-T cells induce outstanding responses in a subset of hematological malignancies, responses are much more deficient in solid tumors. Moreover, NK cells have not shown remarkable results up to date. In general, immune cells present high plasticity to change their activity and phenotype depending on the stimuli they receive from molecules secreted in the tumor microenvironment (TME). Consequently, immune cells will also secrete molecules that will shape the activities of other neighboring immune and tumor cells. Specifically, NK cells can polarize to activities as diverse as angiogenic ones instead of their killer activity. In addition, tumor cell phagocytosis by macrophages, which is required to remove dying tumor cells after the attack of NK cells or CAR-T cells, can be avoided in the TME. In addition, chemotherapy or radiotherapy treatments can induce senescence in tumor cells modifying their secretome to a known as "senescence-associated secretory phenotype" (SASP) that will also impact the immune response. Whereas the SASP initially attracts immune cells to eliminate senescent tumor cells, at high numbers of senescent cells, the SASP becomes detrimental, impacting negatively in the immune response. Last, CAR-T cells are an attractive option to overcome these events. Here, we review how molecules secreted in the TME by either tumor cells or even by immune cells impact the anti-tumor activity of surrounding immune cells.

Selenium Derivatives as Promising Therapy for Chagas Disease: In Vitro and In Vivo Studies.

Chagas disease is a tropical infection caused by the protozoan parasite Trypanosoma cruzi and a global public health concern. It is a paradigmatic example of a chronic disease without an effective treatment. Current treatments targeting T. cruzi are limited to two obsolete nitroheterocyclic drugs, benznidazole and nifurtimox, which lead to serious drawbacks. Hence, new, more effective, safer, and affordable drugs are urgently needed. Selenium and their derivatives have emerged as an interesting strategy for the treatment of different prozotoan diseases, such as African trypanosomiasis, leishmaniasis, and malaria. In the case of Chagas disease, diverse selenium scaffolds have been reported with antichagasic activity in vitro and in vivo. On the basis of these premises, we describe the in vitro and in vivo trypanocidal activity of 41 selenocompounds against the three morphological forms of different T. cruzi strains. For the most active selenocompounds, their effect on the metabolic and mitochondrial levels and superoxide dismutase enzyme inhibition capacity were measured in order to determine the possible mechanism of action. Derivative 26, with a selenocyanate motif, fulfills the most stringent in vitro requirements for potential antichagasic agents and exhibits a better profile than benznidazole in vivo. This finding provides a step forward for the development of a new antichagasic agent.

New Amides and Phosphoramidates Containing Selenium: Studies on Their Cytotoxicity and Antioxidant Activities in Breast Cancer.

Breast cancer is a multifactor disease, and many drug combination therapies are applied for its treatment. Selenium derivatives represent a promising potential anti-breast cancer treatment. This study reports the cytotoxic activity of forty-one amides and phosphoramidates containing selenium against five cancer cell lines (MCF-7, CCRF-CEM, HT-29, HTB-54 and PC-3) and two nonmalignant cell lines (184B5 and BEAS-2B). MCF-7 cells were the most sensitive and the selenoamides I.1f and I.2f and the selenium phosphoramidate II.2d, with GI50 values ranging from 0.08 to 0.93 µM, were chosen for further studies. Additionally, radical scavenging activity for all the compounds was determined using DPPH and ABTS colorimetric assays. Phosphoramidates turned out to be inactive as radical scavengers. No correlation was observed for the antioxidant activity and the cytotoxic effect, except for compounds I.1e and I.2f, which showed dual antioxidant and antitumor activity. The type of programmed cell death and cell cycle arrest were determined, and the results provided evidence that I.1f and I.2f induced cell death via autophagy, while the derivative II.2d provoked apoptosis. In addition, Western blot analysis corroborated these mechanisms with an increase in Beclin1 and LC3-IIB and reduced SQSTM1/p62 levels for I.1f and I.2f, as well as an increase in BAX, p21 and p53 accompanied by a decrease in BCL-2 levels for derivative II.2d.

3,5-Dimethyl-4-isoxazoyl selenocyanate as promising agent for the treatment of Leishmania infantum-infected mice.

Compounds 1 and 2 (selenocyanate and diselenide derivatives, respectively) were evaluated for their potential use in vivo against visceral leishmaniasis (VL). Both entities showed low cytoxicity in vitro in Vero and Caco-2 cell lines. However, the compounds were not suitable for their oral administration, since they exhibited poor values of intestinal permeability in vitro. Microsomal stability assays did not show any metabolite for compound 1 after 120 min, whereas 2 was highly metabolized by the enzyme CYP450. Thus, the in vivo efficacy of compound 1 was assessed in a murine model of L. infantum VL. The daily i.v. administration of 1 mg/kg of compound 1 during 5 consecutive days reduced parasite load in liver, spleen and bone marrow (99.2%, 91.7% and 61.4%, respectively) compared to non-treated mice. To the best of our knowledge, this is the first time that a selenium compound has been tested in vivo against VL. Thus, this work evidences the possible usefulness of selenocyanate derivatives for the treatment of this disease.

New Amides Containing Selenium as Potent Leishmanicidal Agents Targeting Trypanothione Reductase.

Two new series of 28 selenocyanate and diselenide derivatives containing amide moieties were designed, synthesized, and evaluated for their leishmanicidal activity against Leishmania infantum axenic amastigotes, and selectivity was assessed in human THP-1 cells. Eleven compounds exhibited excellent leishmanicidal activity with EC50 values lower than the reference drug miltefosine (EC50 = 2.84 µM). In addition, for six of them the selectivity index ranged from 9 to >1,442, greater than both references used. The most potent and selective compounds were compounds 2h, 2k, and 2m that displayed EC50 values of 0.52, 1.19, and 0.50 µM, respectively, and a high selectivity index (SI) when tested against THP-1 monocytic cells (SI = >1,442, >672, and >1,100, respectively). These derivatives showed an efficacy similar to that of the reference drugs but much better SI values. They also showed interesting activity values against infected macrophages. Trypanothione reductase (TryR) activity and intracellular thiol level measurement assays were performed for the three best compounds in an attempt to elucidate their mechanism of action. Despite that the new analogs exhibited comparable or better inhibitory activities than the reference TryR inhibitors, more studies are necessary to confirm this result. In summary, our findings suggest that the three compounds described here could constitute leading leishmanicidal drug candidates.

Pre-clinical evidences of the antileishmanial effects of diselenides and selenocyanates.

A series of thirty-one selenocompounds covering a wide chemical space was assessed for in vitro leishmanicidal activities against Leishmania infantum amastigotes. The cytotoxicity of those compounds was also evaluated on human THP-1 cells. Interestingly most tested derivatives were active in the low micromolar range and seven of them (A.I.3, A.I.7, B.I.1, B.I.2, C.I.7 C.I.8 and C.II.8) stood out for selectivity indexes higher than the ones exhibited by reference compounds mitelfosine and edelfosine. These leader compounds were evaluated against infected macrophages and their trypanothione reductase (TryR) inhibition potency was measured to further approach the mechanism by which they caused their action. Among them diselenide tested structures were pointed out for their ability to reduce infection rates. Three of the leader compounds inhibited TryR effectively, therefore this enzyme may be implicated in the mechanism of action by which these compounds cause their leishmanicidal effect.

Tellurides Bearing Sulfonamides as Novel Inhibitors of Leishmanial Carbonic Anhydrase with Potent Antileishmanial Activity.

We report for the first time a novel series of tellurides bearing sulfonamide as selective and potent inhibitors of the ß-class carbonic anhydrase (CA; EC 4.2.1.1) enzyme expressed in Leishmania donovani protozoa. Such derivatives showed high activity against axenic amastigotes, and among them, compound 5g (4-(((3,4,5-trimethoxyphenyl)tellanyl)methyl)benzenesulfonamide) showed an IC50 of 0.02 µM being highly selective for the parasites over THP-1 cells with a selectivity index of 300. The in vitro and in vivo toxicity experiments showed compound 5g to possess a safe profile and thus paving the way for tellurium-containing compounds as novel drug entities.

Discovery of new organoselenium compounds as antileishmanial agents.

We report new organoselenium compounds bearing the sulfonamide moiety as effective inhibitors of the ß-isoform of Carbonic Anhydrase from the unicellular parasitic protozoan L. donovani chagasi. All derivatives were evaluated in vitro for their leishmanicidal activities against Leishmania infantum amastigotes along with their cytotoxicities in human THP-1 cells. Compounds 3e-g showed their activity in the low micromolar range with IC50 values spanning from 0.72 to 0.81 µM and selectivity indexes (SI) > 8 (for 3g SI > 30), thus much higher than those observed for the reference drugs miltefosine and edelfosine. This is the first study which reports new selenoderivatives with promising leishmanicidal properties and acting as Carbonic Anhydrase inhibitors too thus paving the way to the development of innovative agents for the treatment of neglected diseases such as leishmaniasis.