A Picrocrocin-Enriched Fraction from a Saffron Extract Affects Lipid Homeostasis in HepG2 Cells through a Non-Statin-like Mode.

Dyslipidemia is a lipid metabolism disorder associated with the loss of the physiological homeostasis that ensures safe levels of lipids in the organism. This metabolic disorder can trigger pathological conditions such as atherosclerosis and cardiovascular diseases. In this regard, statins currently represent the main pharmacological therapy, but their contraindications and side effects limit their use. This is stimulating the search for new therapeutic strategies. In this work, we investigated in HepG2 cells the hypolipidemic potential of a picrocrocin-enriched fraction, analyzed by high-resolution 1H NMR and obtained from a saffron extract, the stigmas of Crocus sativus L., a precious spice that has already displayed interesting biological properties. Spectrophotometric assays, as well as expression level of the main enzymes involved in lipid metabolism, have highlighted the interesting hypolipidemic effects of this natural compound; they seem to be exerted through a non-statin-like mechanism. Overall, this work provides new insights into the metabolic effects of picrocrocin, thus confirming the biological potential of saffron and paving the way for in vivo studies that could validate this spice or its phytocomplexes as useful adjuvants in balancing blood lipid homeostasis.

Smart Lipid-Polysaccharide Nanoparticles for Targeted Delivery of Doxorubicin to Breast Cancer Cells.

In this study, actively-targeted (CD44-receptors) and dual stimuli (pH/redox)-responsive lipid-polymer nanoparticles were proposed as a delivery vehicle of doxorubicin hydrochloride in triple negative breast cancer cell lines. A phosphatidylcholine lipid film was hydrated with a solution of oxidized hyaluronic acid and doxorubicin, chosen as model drug, followed by a crosslinking reaction with cystamine hydrochloride. The obtained spherical nanoparticles (mean diameter of 30 nm) were found to be efficiently internalized in cancer cells by a receptor-mediated endocytosis process, and to modulate the drug release depending on the pH and redox potential of the surrounding medium. In vitro cytotoxicity assays demonstrated the safety and efficacy of the nanoparticles in enhancing the cytotoxic effect of the free anticancer drug, with the IC50 values being reduced by two and three times in MDA-MB-468 and MDA-MB-231, respectively. The combination of self-assembled phospholipid molecules with a polysaccharide counterpart acting as receptor ligand, and stimuli-responsive chemical moieties, was carried out on smart multifunctional nanoparticles able to actively target breast cancer cells and improve the in vitro anticancer activity of doxorubicin.

Santolina pinnata Viv. Exerts Promising Antitumor Activity against Breast Cancer Cells and Anti-Inflammatory Effects in LPS-Stimulated RAW 264.7 Cells.

Cancer is one of the largest causes of mortality in the world, and due to its incidence, the discovery of novel anticancer drugs is of great importance. Many successful anticancer drugs used in clinical practices are derived from natural products. The genus Santolina is a group of species distributed in the Mediterranean area and used in traditional medicine for their biological properties. The aim of this work was to investigate, for the first time, the multi-target biological potential of Italian Santolina pinnata in relation to their chemical profile, by which an interesting natural source of valuable phytochemicals endowed with anticancer and anti-inflammatory features could be assessed. n-Hexane (EHSP) and methanol (EMSP) extracts were investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography (UHPLC), respectively. Anti-proliferative activity was analyzed on MCF-7 and MDA-MB-231 breast cancer cells, as well as on non-tumorigenic MCF-10A cells, by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Apoptotic death was assessed by comet assay. Cell motility and invasive features were examined in highly invasive MDA-MB-231 by wound-healing scratches, while, in both breast cancer cell lines, by gel-zymography experiments. The anti-inflammatory potential was analyzed by nitric oxide (NO) production and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) staining experiments in bacterial lipopolysaccharides (LPS) which stimulated RAW 264.7 cells. EHSP and EMSP extracts exhibited anticancer activity against breast cancer cells, promoting apoptotic death, as well as decreasing cell migration and invasive behaviours. The highest activity (IC50 of 15.91 µg/mL) was detected against MDA-MB-231 cells, a highly invasive breast cancer cell line. Both extracts were also able to promote anti-inflammatory effects (IC50 values ranging from 27.5 to 61.14 µg/mL), as well as to reduce NO levels by inducing inhibitory effects on NF-κB nuclear translocation in LPS-stimulated RAW 264.7 cells. The different biological behaviours found between the extracts could be related to their different chemical compositions. Herein, the multi-target biological potential of S. pinnata in inducing antitumor and anti-inflammatory effects was comprehensively demonstrated. These findings will provide important stepping-stones for further investigations and may lead to the development of highly effective S. pinnata extract-based treatments for breast cancer and inflammatory processes.

Proteomic Profiling of Extracellular Vesicles Released by Leptin-Treated Breast Cancer Cells: A Potential Role in Cancer Metabolism.

Tumor extracellular vesicles (EVs), as endocytic vesicles able to transport nucleic acids, proteins, and metabolites in recipient cells, have been recognized fundamental mediators of cell-to-cell communication in breast cancer. The biogenesis and release of EVs are highly regulated processes and both the quantity of EVs and their molecular cargo might reflect the metabolic state of the producing cells. We recently demonstrated that the adipokine leptin, whose circulating levels correlate with adipose tissue expansion, is an inducer of EV release from breast cancer cells. Here, we show a specific proteomic signature of EVs released by MCF-7 breast cancer cells grown in the presence of leptin (Lep-EVs), in attempt to find additional molecular effectors linking obesity to breast cancer biology. An analysis of the proteomic profile of Lep-EVs by LC-MS/MS revealed a significant enrichment in biological processes, molecular functions, and cellular components mainly related to mitochondrial machineries and activity, compared to protein content of EVs from untreated breast cancer cells. Metabolic investigations, carried out to assess the autocrine effects of these vesicles on breast cancer cells, revealed that Lep-EVs were able to increase ATP levels in breast cancer cells. This result is associated with increased mitochondrial respiration evaluated by Seahorse analyzer, supporting the concept that Lep-EVs can modulate MCF-7 breast cancer cell oxidative metabolism. Moreover, taking into account the relevance of tumor immune cell crosstalk in the tumor microenvironment (TME), we analyzed the impact of these vesicles on macrophage polarization, the most abundant immune component in the breast TME. We found that tumor-derived Lep-EVs sustain the polarization of M0 macrophages, derived from the human THP-1 monocytic cells, into M2-like tumor-associated macrophages, in terms of metabolic features, phagocytic activity, and increased expression of CD206-positive population. Overall, our results indicate that leptin by inducing the release of EV-enriched in mitochondrial proteins may control the metabolism of MCF-7 breast cancer cells as well as that of macrophages. Characterization of tumor-derived EV protein cargo in an obesity-associated milieu, such as in the presence of elevated leptin levels, might allow identifying unique features and specific metabolic mechanisms useful to develop novel therapeutic approaches for treatment of breast cancer, especially in obese patients.

Targeting the Mitochondrial Metabolic Network: A Promising Strategy in Cancer Treatment.

Metabolic reprogramming is a hallmark of cancer, which implements a profound metabolic rewiring in order to support a high proliferation rate and to ensure cell survival in its complex microenvironment. Although initial studies considered glycolysis as a crucial metabolic pathway in tumor metabolism reprogramming (i.e., the Warburg effect), recently, the critical role of mitochondria in oncogenesis, tumor progression, and neoplastic dissemination has emerged. In this report, we examined the main mitochondrial metabolic pathways that are altered in cancer, which play key roles in the different stages of tumor progression. Furthermore, we reviewed the function of important molecules inhibiting the main mitochondrial metabolic processes, which have been proven to be promising anticancer candidates in recent years. In particular, inhibitors of oxidative phosphorylation (OXPHOS), heme flux, the tricarboxylic acid cycle (TCA), glutaminolysis, mitochondrial dynamics, and biogenesis are discussed. The examined mitochondrial metabolic network inhibitors have produced interesting results in both preclinical and clinical studies, advancing cancer research and emphasizing that mitochondrial targeting may represent an effective anticancer strategy.

PBX1: a TALE of two seasons-key roles during development and in cancer.

Pre-B cell leukemia factor 1 (PBX1) is a Three Aminoacid Loop Extension (TALE) homeodomain-containing transcription factor playing crucial roles in organ pattering during embryogenesis, through the formation of nuclear complexes with other TALE class and/or homeobox proteins to regulate target genes. Its contribution to the development of several organs has been elucidated mainly through the study of murine knockout models. A crucial role for human development has been recently highlighted through the discovery of different de novo pathogenic PBX1 variants in children affected by developmental defects. In the adult, PBX1 is expressed in selected tissues such as in the brain, in the gastro-intestinal and urinary systems, or in hematopoietic stem and progenitor cells, while in other organs is barely detectable. When involved in the t(1;19) chromosomal translocation it acts as an oncogene, since the resulting fusion protein drives pre-B cell leukemia, due to the induction of target genes not normally targeted by the native protein. Its aberrant expression has been associated to tumor development, progression, or therapy-resistance as in breast cancer, ovarian cancer or myeloproliferative neoplasm (MPN). On the other hand, in colorectal cancer PBX1 functions as a tumor suppressor, highlighting its context-dependent role. We here discuss differences and analogies of PBX1 roles during embryonic development and in cancer, focusing mainly on the most recent discoveries.

New insights into cholesterol-mediated ERRα activation in breast cancer progression and pro-tumoral microenvironment orchestration.

Breast cancer remains the greatest cause of cancer-related death in women worldwide. Its aggressiveness and progression derive from intricate processes that occur simultaneously both within the tumour itself and in the neighbouring cells that make up its microenvironment. The aim of the present work was firstly to study how elevated cholesterol levels increase tumour aggressiveness. Herein, we demonstrate that cholesterol, by activating ERRα pathway, promotes epithelium-mesenchymal transition (EMT) in breast cancer cells (MCF-7 and MDA-MB-231) as well as the release of pro-inflammatory factors able to orchestrate the tumour microenvironment. A further objective of this work was to study the close symbiosis between tumour cells and the microenvironment. Our results allow us to highlight, for the first time, that breast cancer cells exposed to high cholesterol levels promote (a) greater macrophages infiltration with induction of an M2 phenotype, (b) angiogenesis and endothelial branching, as well as (c) a cancer-associated fibroblasts (CAFs) phenotype. The effects observed could be due to direct activation of the ERRα pathway by high cholesterol levels, since the simultaneous inhibition of this pathway subverts such effects. Overall, these findings enable us to identify the cholesterol-ERRα synergy as an interesting target for breast cancer treatment.

Interfering with the ERC1-LL5ß interaction disrupts plasma membrane-Associated platforms and affects tumor cell motility.

Cell migration requires a complex array of molecular events to promote protrusion at the front of motile cells. The scaffold protein LL5ß interacts with the scaffold ERC1, and recruits it at plasma membrane-associated platforms that form at the front of migrating tumor cells. LL5 and ERC1 proteins support protrusion during migration as shown by the finding that depletion of either endogenous protein impairs tumor cell motility and invasion. In this study we have tested the hypothesis that interfering with the interaction between LL5ß and ERC1 may be used to interfere with the function of the endogenous proteins to inhibit tumor cell migration. For this, we identified ERC1(270-370) and LL5ß(381-510) as minimal fragments required for the direct interaction between the two proteins. The biochemical characterization demonstrated that the specific regions of the two proteins, including predicted intrinsically disordered regions, are implicated in a reversible, high affinity direct heterotypic interaction. NMR spectroscopy further confirmed the disordered nature of the two fragments and also support the occurrence of interaction between them. We tested if the LL5ß protein fragment interferes with the formation of the complex between the two full-length proteins. Coimmunoprecipitation experiments showed that LL5ß(381-510) hampers the formation of the complex in cells. Moreover, expression of either fragment is able to specifically delocalize endogenous ERC1 from the edge of migrating MDA-MB-231 tumor cells. Coimmunoprecipitation experiments show that the ERC1-binding fragment of LL5ß interacts with endogenous ERC1 and interferes with the binding of endogenous ERC1 to full length LL5ß. Expression of LL5ß(381-510) affects tumor cell motility with a reduction in the density of invadopodia and inhibits transwell invasion. These results provide a proof of principle that interfering with heterotypic intermolecular interactions between components of plasma membrane-associated platforms forming at the front of tumor cells may represent a new approach to inhibit cell invasion.

CD44-targeted nanoparticles with GSH-responsive activity as powerful therapeutic agents against breast cancer.

DOX-loaded nanoparticles able to actively target CD44-receptors and respond to redox stimuli were proposed as non-conventional chemotherapeutic strategy in breast cancer. A covalent conjugate of human serum albumin and hyaluronic acid was prepared and assembled by a GSH-mediated desolvation in disulfide-crosslinked solid nanoparticles with mean diameter of 120 nm ± 3.4. The effective internalization of nanoparticles in cancer cells via CD44-receptors, together with the more efficient intracellular release, resulted in a significant increase of drug efficacy, with IC50 reduced from 0.9959 and 2.516 µg mL-1 to 0.4014 and 0.3094 µg mL-1 for MCF-7 and MDA-MB-231, respectively. Conversely, no enhancement in drug toxicity was recorded in healthy MCF-10A cells. The efficacy of the proposed formulation was further investigated in the different biological steps involved in metastasis process, paving the way for further in vivo experiments.

Ultrasound-Assisted Extraction, Chemical Characterization, and Impact on Cell Viability of Food Wastes Derived from Southern Italy Autochthonous Citrus Fruits.

Citrus fruits are one of the principal fruits used to produce juices. Over the years, these fruits have been recognized as new health-promoting agents. In this work, food wastes derived from autochthonous citrus fruits of Southern Italy, named Limone di Rocca Imperiale, Arancia Rossa Moro, and Arancia Bionda Tardivo from Trebisacce, were analyzed. After fresh-squeezing juice, peel and pomace were employed to obtain six different extracts using an ultrasound-assisted method in a hydroalcoholic solvent. The extracts were analyzed in terms of qualitative composition, antioxidant properties, and antiproliferative activity on MCF-7, MDA-MB-231, and BJ-hTERT cell lines. GC-MS and LC-ESI-MS analyses showed different compounds: of note, limonin-hexoside, neodiosmin, obacunone glucoside, and diacetyl nomilinic acid glucoside have been identified as limonoid structures present in all the samples, in addition to different polyphenols including naringenin-glucoside, hesperetin-O-hexoside-O-rhamnoside-O-glucoside, diferuloyl-glucaric acid ester, chlorogenic acid, and the presence of fatty acids such as palmitic, myristic, and linoleic acids. These extracts were able to exert antioxidant activity as demonstrated by DPPH and ABTS assays and, although at higher doses, to reduce the cell viability of different solid tumor cell lines, as shown in MTT assays.

Anticancer potential of novel α,ß-unsaturated γ-lactam derivatives targeting the PI3K/AKT signaling pathway.

Six recently synthesized alkyl (Z)-2-(2-oxopyrrolidin-3-ylidene)acetates were evaluated for their potential as cytotoxic and anticancer agents. All compounds were tested in the ERα positive MCF-7, triple negative MDA-MB-231, and Her2+ SKBR-3 breast cancer cell lines. The most lipophilic derivatives, bearing the 4-isopropylphenyl (2) or 4-tert-butylphenyl (3) group at the γ-lactam nitrogen, proved to be cytotoxic against all the cancer cell lines tested (IC50 values ranging from 18 to 63 µM), exerting their greatest activity in SKBR-3 cells, with IC50 values of 33 and 18 µM, respectively. Biological studies showed that the cytotoxic effects of 2 and 3 are accompanied by apoptotic death in breast cancer cells, and both compounds showed no significant toxicity on healthy cells (e.g., MCF-10A) and red blood cells. An in-depth mechanistic study based on molecular biology, immunoblotting analysis and in silico docking calculations suggested that α,ß-unsaturated γ-lactam derivatives could interfere with the functioning of PI3K and PDK-1, two key enzymes in the PI3K/AKT signaling pathway, whose overactivation is related to the regulation of cell growth and survival in several malignancies.

New Insights into the Antioxidant and Anti-Inflammatory Effects of Italian Salvia officinalis Leaf and Flower Extracts in Lipopolysaccharide and Tumor-Mediated Inflammation Models.

This work aimed to investigate and compare the in vitro antioxidant and anti-inflammatory effects of Salvia officinalis L. (sage) from Italy, with the aim of raising its current knowledge in this field. Leaves and flowers (S1-S8), harvested in two areas of Southern Italy, were extracted with methanol as a solvent by maceration or ultrasound-assisted extraction. Sage extracts, analysed by high pressure liquid chromatography-diode-array detection-electrospray ionization-quadrupole-mass spectroscopy (HPLC-DAD-ESI-Q-MS), exerted a promising antioxidant activity investigated using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ß-carotene bleaching tests, and elicited a significant decrease in reactive oxygen species (ROS) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages. The anti-inflammatory activity was analysed in the same in vitro model. All the extracts did not affect cell viability although they showed anti-inflammatory activity, as they induced a decrease in nitrite levels that was greater than 50%, when employed at 50 µg/mL. Furthermore, they elicited a decrease in nitrite levels, as well as a decline in pro-inflammatory cytokine expression. The NF-κB transcription factor proved to be involved in the mechanisms that underlie such effects. Interestingly, sage extracts were able to interfere with the inflammatory activity induced by breast cancer cell-conditioned media (nitrite levels were significantly decreased, p < 0.05; p < 0.01), highlighting for the first time the important role of S. officinalis in controlling inflammation processes related to neoplastic progression.

Cholesterol and Mevalonate: Two Metabolites Involved in Breast Cancer Progression and Drug Resistance through the ERRα Pathway.

Breast cancer is the second greatest cause of cancer-related death in women. Resistance to endocrine treatments or chemotherapy is a limiting drawback. In this context, this work aims to evaluate the effects of cholesterol and mevalonate during tumor progression and their contribution in the onset of resistance to clinical treatments in use today. In this study, we demonstrated that cholesterol and mevalonate treatments were able to activate the estrogen-related receptor alpha (ERRα) pathway, increasing the expression levels of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), ERbB2/human epithelial receptor (HER2), tumor protein D52 (TPD52), and NOTCH2 proteins in breast cancer cells. The activation of this pathway is shown to be responsible for intense metabolic switching, higher proliferation rates, sustained motility, the propagation of cancer stem-like cells (CSCs), and lipid droplet formation. All of these events are related to greater tumor propagation, aggressiveness, and drug resistance. Furthermore, the activation and expression of proteins induced by the treatment with cholesterol or mevalonate are consistent with those obtained from the MCF-7/TAMr cell line, which is largely used as a breast cancer model of acquired endocrine therapy resistance. Altogether, our data indicate that cholesterol and mevalonate are two metabolites implicated in breast cancer progression, aggressiveness, and drug resistance, through the activation of the ERRα pathway. Our findings enable us to identify the ERRα receptor as a poor prognostic marker in patients with breast carcinoma, suggesting the correlation between cholesterol/mevalonate and ERRα as a new possible target in breast cancer treatment.

Deferiprone (DFP) Targets Cancer Stem Cell (CSC) Propagation by Inhibiting Mitochondrial Metabolism and Inducing ROS Production.

Deferiprone (DFP), also known as Ferriprox, is an FDA-approved, orally active, iron chelator that is currently used clinically for the treatment of iron-overload, especially in thalassaemia major. As iron is a critical factor in Fe-S cluster assembly that is absolutely required for the metabolic function of mitochondria, we hypothesized that DFP treatment could be used to selectively target mitochondria in cancer stem cells (CSCs). For this purpose, we used two ER(+) human breast cancer cell lines, namely MCF7 and T47D cells, as model systems. More specifically, a 3D tumorsphere assay was employed as a functional readout of CSC activity which measures anchorage-independent growth under low attachment conditions. Here, we show that DFP dose dependently inhibited the propagation of CSCs, with an IC-50 of ~100 nM for MCF7 and an IC-50 of ~0.5 to 1 µM for T47D cells, making DFP one the most potent FDA-approved drugs that we and others have thus far identified for targeting CSCs. Mechanistically, we show that high concentrations of DFP metabolically targeted both mitochondrial oxygen consumption (OCR) and glycolysis (extracellular acidification rates (ECAR)) in MCF7 and T47D cell monolayers. Most importantly, we demonstrate that DFP also induced a generalized increase in reactive oxygen species (ROS) and mitochondrial superoxide production, and its effects reverted in the presence of N-acetyl-cysteine (NAC). Therefore, we propose that DFP is a new candidate therapeutic for drug repurposing and for Phase II clinical trials aimed at eradicating CSCs.

Chemical Profile, Antioxidant, Anti-Inflammatory, and Anti-Cancer Effects of Italian Salvia rosmarinus Spenn. Methanol Leaves Extracts.

In this study, we evaluated and compared the chemical composition, the antioxidant, anti-inflammatory, and anti-proliferative effects of four methanol extracts (R1-R4), of Salvia rosmarinus Spenn. in two different sites of Southern Italy obtained by maceration or ultrasound-assisted extraction. Extracts of S. rosmarinus collected on the Ionian coast are indicated with the abbreviations R1 (maceration) and R2 (ultrasound-assisted extraction). Extracts of S. rosmarinus collected on the Tyrrhenian coast are indicated with the abbreviations R3 (maceration) and R4 (ultrasound-assisted extraction). The chemical composition was analyzed using High Pressure liquid chromatography-Diod-Array detection-Electrospray ionization-Quadrupole-Mass Spectroscopy (HPLC-DAD-ESI-Q-MS). The antioxidant activity was analyzed by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) 2,2-diphenyl-1-picrylhydrazyl (DPPH), ß-carotene bleaching, and Ferric Reducing Antioxidant Power (FRAP) assays. Antioxidant features were also assessed in lipopolysaccharide (LPS)-stimulated RAW-264.7 murine macrophages, evaluating Reactive Oxygen Species (ROS) production; in the same experimental model, the anti-inflammatory activity of the extracts was investigated. Interestingly, all extracts displayed antioxidant and anti-inflammatory properties. They exhibited significative nitrite production inhibitory activity, whith IC50 values ranging from 3.46 to 5.53 µg/mL, without impairing cell viability. The anti-inflammatory activity was also investigated by Western Blotting and immunofluorescence assay, highlighting the R3 and R4 extracts ability to reduce NF-κB translocation, as well as to disrupt the MAPKs signaling pathway. Extracts exhibited both potential anti-proliferative activity on breast cancer cells, inducing apoptosis, without affecting non-tumorigenic cells, and the ability to inhibit MDA-MB-231 cells' motility. Finally, the rosemary extracts treatment significantly reduced the power of conditioned media, from MCF-7 or MDA-MB-231 cells to induce nitrite production on RAW 264.7 cells, confirming their promising anti-inflammatory activity.

3-Amino-alkylated indoles: unexplored green products acting as anti-inflammatory agents.

Aim: Over the years, indole has proved to be a versatile scaffold for the design of molecules acting as anti-inflammatory agents. Materials & Methods: A small library of 3-amino-alkylated indoles has been obtained by an optimized Mannich green approach. The anti-inflammatory activity of the new 3-amino-alkylated indoles, GLYC 0-10, was evaluated in RAW 264.7 macrophages. Results: The anti-inflammatory activity of the new 3-amino-alkylated indoles, GLYC 0-10, was evaluatedn and, among them, GLYC 4, 5 and 9 displayed the greatest inhibitory effects on nitric oxide production, with IC50 values of 5.41, 4.22 and 6.3 µM, respectively. Conclusion: Our outcomes, overall, highlight the importance of the indole substitution in the anti-inflammatory activity of these compounds, exerted by acting on the interlinked NF-κB/ERK1/2 pathways.

5-(Carbamoylmethylene)-oxazolidin-2-ones as a Promising Class of Heterocycles Inducing Apoptosis Triggered by Increased ROS Levels and Mitochondrial Dysfunction in Breast and Cervical Cancer.

Oxazolidinones are antibiotics that inhibit protein synthesis by binding the 50S ribosomal subunit. Recently, numerous worldwide researches focused on their properties and possible involvement in cancer therapy have been conducted. Here, we evaluated in vitro the antiproliferative activity of some 5-(carbamoylmethylene)-oxazolidin-2-ones on MCF-7 and HeLa cells. The tested compounds displayed a wide range of cytotoxicity on these cancer cell lines, measured by MTT assay, exhibiting no cytotoxicity on non-tumorigenic MCF-10A cells. Among the nine tested derivatives, four displayed a good anticancer potential. Remarkably, OI compound showed IC50 values of 17.66 and 31.10 µM for MCF-7 and HeLa cancer cells, respectively. Furthermore, we assessed OI effect on the cell cycle by FACS analysis, highlighting a G1 phase arrest after 72 h, supported by a low expression level of Cyclin D1 protein. Moreover, mitochondrial membrane potential was reduced after OI treatment driven by high levels of ROS. These findings demonstrate that OI treatment can inhibit MCF-7 and HeLa cell proliferation and induce apoptosis by caspase-9 activation and cytochrome c release in the cytosol. Hence, 5-(carbamoylmethylene)-oxazolidin-2-ones have a promising anticancer activity, in particular, OI derivative could represent a good candidate for in vivo further studies and potential clinical use.

Naturally occurring sesquiterpene lactones and their semi-synthetic derivatives modulate PGE2 levels by decreasing COX2 activity and expression.

Plants of the Asteraceae family have been used in traditional medicine for centuries due to their main antimicrobial and analgesic activities. A liniment from Artemisia californica has recently been tested on patients affected by either acute pain or chronic pain conditions with great success. The aim of this study was to evaluate the anti-inflammatory activity of sesquiterpene lactones (SLs), representing the majority in the Asteraceae family. Leucodin, α-santonin and sclareolide (three SLs) were chosen to undergo chemical modifications. This pool of molecules underwent molecular modeling experiments using an in-house program, WATGEN, predicting the water network and its contribution to the overall affinity of the enzyme-ligand complex. The anti-inflammatory activity and the ability of compounds to modulate COX-2 expression have been evaluated in LPS-stimulated RAW 264.7 cells and in RIF-1 cells treated according to the Photodynamic Therapy (PDT) protocols using Photoprin (PH) as photosensitizer. Furthermore, commercially available assay kits were used to evaluate the concentration of PGE-2 and the direct inhibition of COX-2. All the tested molecules fit well in the enzyme binding pocket, but to get a substantial inhibition of the expression and activity of the enzyme as well as a reduction in the PGE2 concentration, high concentrations of the compounds are needed. The only exceptions being leucodin itself and FP6, one of the α-santonin derivatives, presenting a CF3 functional group. We believe that this class of compounds has some interesting potential in the treatment of pain and inflammation. Although, the activity seems to be due to a mechanism related to the expression of the COX enzymes rather than on a direct inhibition.

Corrigendum to "Naturally occurring sesquiterpene lactones and their semi-synthetic derivatives modulate PGE2 levels by decreasing COX2 activity and expression" [Heliyon 5 (3) (March 2019) e01366].

[This corrects the article DOI: 10.1016/j.heliyon.2019.e01366.].

Thioalbamide, A Thioamidated Peptide from Amycolatopsis alba, Affects Tumor Growth and Stemness by Inducing Metabolic Dysfunction and Oxidative Stress.

Thioalbamide, a thioamidated peptide biosynthesized by Amycolatopsis alba, is a thioviridamide-like molecule, and is part of a family of natural products representing a focus of biotechnological and pharmaceutical research in recent years due to their potent anti-proliferative and cytotoxic activities on malignant cells. Despite the high antitumor potential observed at nanomolar concentrations, the mechanisms underlying thioalbamide activity are still not known. In this work, the cellular effects induced by thioalbamide treatment on breast cancer cell lines were evaluated for the first time, highlighting the ability of this microbial natural peptide to induce mitochondrial dysfunction, oxidative stress, and apoptotic cell death. Furthermore, we demonstrate that thioalbamide can inhibit the propagation of cancer stem-like cells, which are strongly dependent on mitochondrial function and are responsible for chemotherapy resistance, metastasis, and tumor recurrence.