A series of novel indole derivatives containing ester groups, halogen, epoxy and short-chain aliphatic hydrocarbons were designed, synthesized and evaluated for their antibacterial activities. Most of the compounds showed relatively excellent inhibitory activities against different strains (including a multidrug-resistant clinical isolate). Compounds 1f, 1o and 1r showed the strongest inhibitory activity (mic of 2-32 μg/ml). Compounds 1f, 1h, 1i, 1o and 1r with antibacterial activity were not cytotoxic against RAW 264.7 mouse macrophages. Structure-activity relationship analysis and docking studies showed that halogens as well as aliphatic hydrocarbons could enhance the antibacterial ability and reduce the toxicity of the indole compounds

Mitoxantrone (MTX) is a chemotherapeutic agent used to treat solid tumors and hematological malignancies, as well as multiple sclerosis. Nevertheless, MTX has been associated with serious adverse side effects, such as cardiotoxicity. Considering that aging is a known risk factor for the development of cardiovascular diseases and cancer, our study aimed to assess the molecular effects of MTX on cardiac muscle of aged mice. Old male CD-1 mice (19 months) received a pharmacologically relevant dose of MTX, consisting of 6 intraperitoneal administrations for three weeks (biweekly) to achieve a cumulative dose of 4.5 mg/kg of MTX (MTX group) or saline (CTRL group). Animal experiments were performed with the approval of the national competent authorities - General Directorate of Food and Veterinary Medicine (DGAV), and mice welfare was monitored daily. Mice were sacrificed two months after the last administration for collection of blood and heart. MTX group showed an increase in serum glucose levels, despite no other differences. Regarding the heart, MTX decreased the content of glucose transporter GLUT4 (GLUT4) and phosphofructokinase (PFKM), suggesting a lower use of glycolysis. Despite no major differences for the mitochondrial biogenesis markers evaluated, the content of autophagy protein 5 (ATG5), atrogin, and CCAAT-enhancer-binding proteins β (CEBPβ) was decreased in the MTX group, highlighting the influence of this drug on cardiac autophagy, proteolysis, and regeneration, respectively. These results suggest that MTX impacts unexplored pathways, so further studies are needed to find new molecular mechanisms that explain the cardiotoxicity induced by this anticancer agent.

Abstract

Cancer is a challenging disease to treat, regarding treatment efficiency and side-effects. To overcome these problems, extensive studies are exploring therapies with reduced side-effects, such as photodynamic therapy (PDT). PDT has advantages over conventional therapies, however its dependence on light limits it to treating tumors under the skin/ outer lining of organs [1]. We have developed new photosensitizers self-activated intracellularly with tumor-selectivity based on chemiluminescent reactions involving a cancer marker. The photosensitizer is directly chemiexcited to a triplet excited state generating singlet oxygen, without an external light source. Thus, we aimed to develop self-activating photosensitizers which can be used for light-free photodynamic therapy, eliminating its light-related restrictions [2,3]. Cytotoxicity assays with breast and prostate cell lines showed that the novel photosensitizers possess significant toxicity toward tumor cells, while not affecting normal cells. Besides we compared the activity of these compounds with standard treatments, finding higher cytotoxicity [3].

Acknowledgements

Projects PTDC/QUI-QFI/2870/2020 and UIDB/00081/2020. C.M. acknowledges FCT for the PhD grant (SFRH/BD/143211/2019).

References

[1] M. Magalhães, C. G. Esteves, and L. Pinto, Chemphyschem, 17, 2016, 2286 – 2294.

[2] Luís Pinto da Silva , Ara Núnez-Montenegro , Carla M. Magalhães , Paulo J.O. Ferreira, Diana Duarte , Patricia Gonzalez-Berdullas, Jose E. Rodríguez-Borges, Nuno Vale, Joaquim C.G. Esteves da Silva , J. Med.Chem, 183, 2019, 111683.

[3] Luís Pinto da Silva , Carla M. Magalhães , Ara Núñez-Montenegro , Paulo J.O. Ferreira, Diana Duarte, José E. Rodríguez-Borges, Nuno Vale,Joaquim C.G. Esteves da Silva, Biomolecules, 9, 2019, 384.

Strategies for malarial control are met with difficulties due to insufficiency of control measures and emerging parasite drug resistance. Erythrocytes, mainly their lipid rafts-protein, have been demonstrated as targets of Plasmodium parasites interaction for invasion of cells causing infection. GPCRs, viz. ADRB2 with their central role in physiological processes and intricate signaling pathways have been the targets for a range of diseases. In vitro studies have shown signaling via erythrocytic ADRB2 regulates the entry of P. falciparum. Prior studies in our laboratory demonstrated genetic variations of membrane proteins; ADRB2, ADORA2A, ADORA2B, ABCB1 were associated with malaria progression. ADRB2 protein has been extensively studied in the context of etiology and therapeutics of asthma, and its agonists are being used as reliever drugs. Since anti-asthmatics work by internalizing the receptors, well-established drugs with known pharmacokinetic properties and efficacies can be good candidates to treat malaria. Demonstration of proof-of-concept of ADRB2-mediated mechanisms of clinical relevance may provide avenues for drug-repurposing. Erythrocyte cultures were employed to test the anti-malarial activity of β2AR-agonists and antagonists in combination with antimalarials on P. falciparum-infected erythrocytes. SYBR green-I fluorescence assay was performed to study parasite inhibition, and the results analyzed for their synergistic action. Agonist-induced receptor desensitization was assayed using flow cytometry and visualized. In vitro activities of salbutamol, propranolol, and combination treatments demonstrated parasite inhibition with acceptable haemotoxicity. The receptor internalization was found to be incremental and microscopic observations validating β2AR-desensitization were obtained, providing further mechanistic insights into β2AR-mediated parasite invasion.

It has become increasingly popular to use medicinal plants in cancer treatments since researchers have identified anticancer compounds such as paclitaxel, vincristine, and camptothecin in plants. Despite the progress made so far, the challenge of efficacy, selectivity and toxicity persists. In the current study, Erythrina caffra, a commonly used medicinal plant in South Africa was assessed for its anticancer potential. The plant leaves were initially subjected to solvent extraction using N-hexane, dichloromethane, ethylacetate and methanol. The extracts were evaluated for their antioxidant, anticancer, and cell migration inhibitory properties. The phytochemicals were then tentatively identified using gas chromatography mass spectrometry. Sequel to the phytochemical identification, a variety of in silico methods including molecular docking, Quantitative structure-activity relationship modeling (QSAR), and binding free energy calculations were used to screen for potential modulators of the cancer proteins MDM2, CDK2 and CDK6. The compounds showing high inhibitory activity from the screening were assessed for leadlikeness property to identify their suitability as drug candidates. The DCM extract had the best antioxidant and anticancer potential and the in silico analysis revealed drug-like compounds such as 5-bromovaleric acid, 2-methyloct-5-yn-4-ylester, liquiritigenin, di-isooctyl phthalate and 8-ethyl-6,7-dimethyl- lumazine which could act on one or more of the cancer targets to elicit potential anticancer effects. These compounds were also shown to have good oral bioavailability and low toxicity. Overall, the E. caffra extract exhibited significant anticancer potential and contained lead compounds that can be developed in the future as drug candidates in the treatment of cancer.

One of the most common diseases found among men in recent days is prostate cancer (PCa). The growth of cancer is generally due to the activation of the androgen receptor by androgens. Structural modification and molecular docking approaches were done with the protein (PDB ID: 3V49) to identify the novel 7-methoxy-3-((4-phenylpiperazin-1-yl)methyl)-2H-chromen-2-one derivatives. The compounds (5a-g) was synthesized and characterized well by IR, NMR, and LC-MS spectral techniques. The compound 5a and 5b were reconfirmed by single crystal XRD. The in vitro anticancer studies were carried out for the compounds (5a-g) against LNCaP, PC3and 3T3 cell line. Among them 5b showed highest cytotoxicity against LNCaP (10.35 ± 1.22) μM, PC3 (34.65±1.46) μM and reduced cell viability. For the compound 5b, simulations of molecular dynamics are conducted to test protein-ligand interactions. Drug similarity and pharmacokinetic properties for all compounds were anticipated. The outcome of these results may give vital information in further development.

The present study focuses on the chemical composition of the ethyl acetate organic fraction derived from cell-free culture of thermophilic Bacillus licheniformis MK027019 by GC-MS. In addition, the antibacterial activity of the organic fraction against two multidrug-resistant microorganisms is tested using the Radial Diffusion Assay technique. GC-MS analysis revealed that thermophilic B. licheniformis MK027019 produced five major groups of secondary metabolites based on their retention time, molecular formula and molecular weight. These groups were: [Germacrene-D: 14.70%], saturated hydrocarbon [Eicosane: 12.13%, Heneicosane: 3.17%], fatty acid methyl ester [hexadecanoic acid methyl ester: 6.51%, eicosanoic acid methyl ester: 0.78%], alkane [n-Tridecane: 4.39%] and quinoline derivative [8-Phenyl-isoquinoline: 3.51%]. This organic fraction is effective against the multidrug-resistant bacterium Pseudomonas aeruginosa. The presence of Germacrene-D and quinoline derivative are significant in this finding, and to our knowledge, this is the first time these compounds have been detected in thermophilic Bacillus licheniformis.

Mitoxantrone (MTX) is a topoisomerase II inhibitor with anticancer and immunomodulatory properties, however its neurotoxicity is poorly understood. Our work aimed to evaluate the neurotoxicity of a clinically relevant dose of MTX in adult mice.

Three-month-old CD-1 male mice received bi-weekly administrations of MTX for 3 weeks, until they achieved a total cumulative dose of 6 mg/kg. They were sacrificed one week later. Biomarkers of oxidative stress, neuronal damage, apoptosis, and autophagy were analyzed in whole brain, whereas brain sections were used for analysis of the hippocampal formation (HF) and prefrontal cortex (PFC).

Our results demonstrated that MTX induced redox imbalance in the whole brain, namely an increase in endothelial nitric oxide synthase and reduced manganese superoxide dismutase content. Brain oxidative metabolism was altered as seen by diminished subunit β adenosine triphosphate synthase content. MTX increased autophagic microtubule-associated protein light chain 3 II and decreased postsynaptic density protein 95. Regarding regional brain analysis, a reduction in volume was observed in the dentate gyrus and CA1 region of the HF. Total number of glial fibrillary acid protein immunoreactive astrocytes increased in all regions of the HF except in the DG, suggesting extensive astrogliosis. The apoptotic marker Bax increased in the PFC and CA3 region, whereas p53 decreased in all areas evaluated. In the PFC, MTX caused hyperphosphorylation of Tau.

MTX disrupts several pathways in the brain of adult CD-1 mice in a clinically relevant dose, which can lead to cognitive impairment, but further studies are needed to evaluate the putative consequences.

Rheumatoid arthritis (RA) is a progressive, chronic, autoimmune disease, characterized by persistent synovial inflammation and irreversible cartilage and bone damage that affects the synovial joints and adjacent tissues. Presently, effective drugs that can control RA process, remain an unmet need. The role of fibroblast-like synoviocytes (FLS) on synovial inflammation initiation and progression make these cells natural targets for the search for new effective molecules to stop the disease progression. 2-Styrylchromones (2-SC) feature a wide range of biological properties, including antioxidant and anti-inflammatory activities. The present study investigated the effect of six hydroxylated and methoxylated 2-SC on the IL1β-induced increase of ^•NO and iNOS levels in human FLS, pointing the role of NF-κB activation in the process.

From the tested 2-SC, the one presenting two OCH₃ at C-5 and C-7 on A-ring and a catechol group on B-ring, significantly reduced iNOS expression and ^•NO production. These effects seemed to be partially mediated by the reversion of IL-1β-induced cytoplasmic IkBα disappearance and nuclear p65 increase.

These findings may be of great value in the development of new 2-SC which should be further explored and carefully evaluated to reveal their full potential on the RA treatment.

Lung cancer relapse and post-treatment dissemination suggest the presence of drug resistant populations of cells called cancer stem cells (CSCs). Cancer metastases and the risk of secondary tumours are the most frequent causes of mortality in many cases. One important feature of lung cancer prognosis is metastases and the invasive ability of the cells, which is driven by CSCs. Considering CSC proliferation and migration associated with metastases, therapeutic strategies targeting these CSCs are considered to improve long-term clinical outcome. A minimally invasive, clinically approved cancer treatment, Photodynamic therapy (PDT), along with the use of a nano drug carrier was used in this study. PDT is based on the principle of light stimulation of a photosensitizing drug that induces tumour cell death. Nano mediated PDT using gold nanoparticles have been seen to induce cell death in lung CSCs. In this study morphological examination and various physiological experiments including, migration, proliferation, cytotoxicity, population doubling time, and cell cycle analysis assay were conducted to determine whether PDT using a gold nano sensitizer prevents CSC migration and invasion. Results show that the use of nanoPDT using a AlPcS₄Cl and AuNPs conjugate can inhibit CSC migration and invasion, induce cell cycle arrest, and decrease CSC proliferative abilities. The use of a drug nano carrier in the form of AuNPs can improve the effectivity of PDT cancer treatment and specifically facilitate the inhibition of metastasis seen in lung cancer caused by CSCs, which can clinically relate to an improved prognosis.