Glucose transporter-4 (GLUT4) represents the major glucose transporter isoform responsible for glucose uptake into insulin-sensitive cells, primarily in skeletal muscle and adipose tissues. In insulin-resistant conditions, such as type 2 diabetes mellitus, GLUT4 expression and/or translocation to the cell plasma membrane is reduced, compromising cell energy metabolism. Therefore, the use of synthetic or naturally occurring molecules able to stimulate GLUT4 expression represents a good tool for alternative treatments of insulin resistance. The present study aimed to investigate the effects of essential oils (EOs) derived from Pinus spp. (P. nigra and P. radiata) and of their main terpenoid constituents (α- and β-pinene) on the expression/translocation of GLUT4 in myoblast C2C12 murine cells. For this purpose, the chemical profiles of the EOs were first analyzed through gas chromatography–mass spectrometry (GC-MS). Cell viability was assessed by MTT assay, and GLUT4 expression/translocation was evaluated through RT-qPCR and flow cytometry analyses. The results showed that only the P. nigra essential oil (PnEO) and α-pinene can increase the transcription of the Glut4/Scl2a4 gene, resulting in a subsequent increase in the amount of GLUT4 produced and its plasma membrane localization. Moreover, the PnEO or α-pinene can induce Glut4 expression both during myogenesis and in myotubes. In summary, the PnEO and α-pinene emulate insulin’s effect on the GLUT4 transporter expression and its translocation to the muscle cell surface.

Transglutaminase type 2 (TG2) is the most ubiquitously expressed member of the transglutaminase family. TG2 catalyzes the transamidation reaction leading to several protein post-translational modifications and it is also implicated in signal transduction thanks to its GTP binding/hydrolyzing activity. In the nervous system, TG2 regulates multiple physiological processes, such as development, neuronal cell death and differentiation, and synaptic plasticity. Given its different enzymatic activities, aberrant expression or activity of TG2 can contribute to tumorigenesis, including in peripheral and central nervous system tumors. Indeed, TG2 dysregulation has been reported in meningiomas, medulloblastomas, neuroblastomas, glioblastomas, and other adult-type diffuse gliomas. The aim of this review is to provide an overview of the biological and functional relevance of TG2 in the pathogenesis of nervous system tumors, highlighting its involvement in survival, tumor inflammation, differentiation, and in the resistance to standard therapies.

Pressure ulcers (PUs) are a debilitating and often painful condition. They are localized lesions on the skin and/or underlying tissues and are common in the elderly, people with mobility difficulties, diabetics, and vascular disease or malnutrition, as well as in those requiring intensive or palliative care. The prevention and treatment of PUs involve strategies to optimize hydration, circulation, and nutrition. Nutrition plays a key role in pressure ulcer care because wounds require macronutrients and micronutrients to heal. Reports relating to the effectiveness of “Complementary Enzyme Therapy” also in the vulnological field led us to this study, the aim of which was to test the activity of a biodynamic food supplement (Citozym®) rich in carbohydrates, vitamins, and amylase and lactase and characterized by marked antioxidant activity. Citozym® administered topically and/or systemically, and in particular in both administrations, in patients suffering from Pus, has shown a marked reduction in bedsores and, in many cases, complete healing. Furthermore, it was possible to observe a lower incidence of side effects compared to conventional therapies. The results obtained, confirmed by various tests and recognized by the scientific community, allow us to conclude that treatment with Citozym® could represent a new and effective strategy for the treatment of PUs.

EDITORIAL article Front. Oncol., 31 March 2023Sec. Molecular and Cellular Oncology Volume 13 - 2023 | https://doi.org/10.3389/fonc.2023.1188765

Cutaneous melanoma is an immunogenic highly heterogenic tumor characterized by poor outcomes when it is diagnosed late. Therefore, immunotherapy in combination with other anti-proliferative approaches is among the most effective weapons to control its growth and metastatic dissemination. Recently, a large amount of published reports indicate the interest of researchers and clinicians about plant secondary metabolites as potentially useful therapeutic tools due to their lower presence of side effects coupled with their high potency and efficacy. Published evidence was reported in most cases through in vitro studies but also, with a growing body of evidence, through in vivo investigations. Our aim was, therefore, to review the published studies focused on the most interesting phytochemicals whose immunomodulatory activities and/or mechanisms of actions were demonstrated and applied to melanoma models.

Curcumin (CUR) is a natural molecule that is unstable due to the presence of a bis-ketone. To obtain more stable derivatives in biological fluids, the bis-ketone was replaced with pyrazole or O-substituted oximes. Their stability in solution was studied by UV–visible spectrophotometry. The effects on proliferation were studied by MTT assay and/or clonogenicity assay. Induction of apoptosis was evaluated by annexin V staining and Western blot analysis. The bioavailability was obtained from the analysis of the molecular chemical–physical characteristics. The replacement of the bis-ketone with a pyrazole ring or O-substituted oximes improved the stability of all the CUR-derivative molecules. These derivatives were more stable than CUR in solution and were generally cytotoxic on a panel of cancer cell lines tested, and they promoted caspase-dependent apoptosis. Derivative 1 was the most potent in the osteosarcoma (OS) lines. With respect to CUR, this derivative showed cytotoxicity at least three times higher in the MTT assay. In addition, in the clonogenic assay, 1 maintained the activity in conditions of long treatment presumably by virtue of its improved stability in biological fluids. Notably, 1 should have improved chemical–physical characteristics of bioavailability with respect to CUR, which should allow for reaching higher blood levels than those observed in the CUR trials. In conclusion, 1 should be considered in future clinical studies on the treatment of OS, either alone or in combination with other medications currently in use.

Despite curcumin (CUR) inhibiting cell proliferation in vitro by activating apoptotic cell death, its use in pharmacological therapy is hampered by poor solubility, low stability in biological fluids, and rapid removal from the body. Therefore, CUR-derivatives with better biological and chemical–physical characteristics are needed. The bis-ketone moiety of CUR strongly influences its stability in slightly alkaline solutions such as plasma. Here, we considered its replacement with isoxazole, beta-enamine, or oxime groups to obtain more stable derivatives. The evaluation of the chemical–physical characteristics showed that only of the isoxazole derivatives 2 and 22 had better potential than CUR in terms of bioavailability. The UV–visible spectrum analysis showed that derivatives 2 and 22 had better stability than CUR in solutions mimicking the biological fluids. When tested on a panel of cell lines, derivatives 2 and 22 had marked cytotoxicity (IC50 = 0.5 µM) compared with CUR only (IC50 = 17 µM) in the chronic myeloid leukemia (CML)-derived K562 cell line. The derivative 22 was the more selective for CML cells. When administered at the average concentration found for CUR in the blood of patients, derivatives 2 and 22 had potent effects on cell cycle progression and apoptosis initiation, while CUR was ineffective. The apoptotic effect of derivatives 2 and 22 was associated with low necrosis. In addition, derivative 22 was able to reverse drug resistance in K562 cells resistant to imatinib (IM), the reference drug used in CML therapy. The cytotoxicity of derivative 22 on IM-sensitive and resistant cells was associated with upregulation of FOXN3 and CDKN1A expression, G2/M arrest, and triggering of apoptosis. In conclusion, derivative 22 has chemical–physical characteristics and biological effects superior to CUR, which allow us to hypothesize its future use in the therapy of CML and CML forms resistant to IM, either alone or in combination with this drug.

Salt stress represents one of the most problematic abiotic stress affecting plants worldwide. In saline soils, plants try to counteract the consequences of salt stress by physiological changes, leading to the decreasing of both osmotic and oxidative stresses. Plant growth-promoting bacteria (PGPB) can ameliorate plant stress response by several mechanisms. In this work, we focused on the effects of halotolerant strain Arthrobacter globiformis on salt stress response in Brassica napus. The strain was inoculated on seeds of three rapeseed cultivars with different levels of salt tolerance; seed germination and following first phases of development were examined in plants exposed to high salinity. Compared to not inoculated plants under the same saline conditions, the inoculated showed a better stress response in the seedling phase. Moreover, a significant increase in phenolic compounds, as well as in Phenylalanine ammonia-lyase (PAL) and Superoxide dismutase (SOD) enzymatic activities were observed in inoculated plants; the concentration of the osmolyte proline was also significantly enhanced in comparison to the not inoculated ones. A. globiformis was proved to be a promising PGPB strain and it can be a tool to counteract salt stress in quite an effective manner, even at high saline conditions.

Caffeic acid (CA) has shown antitumor activity in numerous solid and blood cancers. We have recently reported that CA is active in reducing proliferation and triggering apoptosis in both Imatinib-sensitive and resistant Chronic Myeloid Leukemia (CML) cells. Tissue transglutaminase type 2 (TG2) enzyme is involved in cell proliferation and apoptosis of numerous types of cancer. However, its activity has different effects depending on the type of tumor. This work investigated the possible involvement of TG2 activation in the triggering of CA-dependent anticancer effects on the K562 cell line, which was studied as a model of CML. CA-dependent changes in TG2 activity were compared with the effects on cell proliferation and apoptosis. The use of N-acetylcysteine (NAC), an antioxidant molecule, suggested that the antiproliferative effect of CA was due to the increase in reactive oxygen species (ROS). The use of a TG2 inhibitor showed that TG2 activity was responsible for the increase in ROS generated by CA and reduced both caspase activation and triggering of CA-dependent apoptosis. The knocking-down of TGM2 transcripts confirmed the crucial involvement of TG2 activation in CML cell death. In conclusion, the data reported, in addition to ascertaining the important role of TG2 activation in the antiproliferative and pro-apoptotic mechanism of CA allowed us to hypothesize a possible therapeutic utility of the molecules capable of triggering the activation pathways of TG2 in the treatment of CML.

As the 2019 coronavirus disease (COVID-19) pandemic rages, there is an urgent need to identify clinical and laboratory predictors for progression to severe and fatal forms of this disease. In this study, we aimed to evaluate the potential ability of a nutritional supplement to normalize certain hematological, biochemical and immunological biomarkers in patients with and without symptoms of COVID-19. Micronutrients, such as nutritionally essential vitamins and minerals, influence and support every step of the immune response. This investigation was performed by administering a dietary supplement rich in calciferol (vitamin D3), ascorbic acid (vitamin C), folic acid (vitamin B9) and pantothenic acid (vitamin B5) to the enrolled patients for 120 days. All essential elements for a complete physiological enzymatic process. The reported results appear promising from the point of view of the experimental approach adopted. In particular, the scheduled administration of the nutritional supplement rich in micronutrients to asymptomatic and mild to moderate COVID-19 patients has led, in general, to the normalization of the values of some critical biochemical and immunological parameters found to be altered. This nutritional approach, although it does not resolve the disease and therefore does not represent a cure, can improve the quality of life of COVID-19 patients.

Plants grown in saline soils undergo osmotic and oxidative stresses, affecting growth and photosynthesis and, consequently, the yield. Therefore, the increase in soil salinity is a major threat to crop productivity worldwide. Plant’s tolerance can be ameliorated by applying simple methods that induce them to adopt morphological and physiological adjustments to counteract stress. In this work, we evaluated the effects of seed priming on salt stress response in three cultivars of rapeseed (Brassica napus L.) that had different tolerance levels. Seed chemical priming was performed with 2.5 mM spermine (SPM), 5 mM spermidine (SPD), 40 mM NaCl and 2.5 mM Ca (NO3)2. Primed and not primed seeds were sown on saline and not saline (controls) media, and morphological and physiological parameters were determined. Since SPD treatment was effective in reducing salinity negative effects on growth, membrane integrity and photosynthetic pigments, we selected this priming to further investigate plant salt stress response. The positive effects of this seed treatment on growth and physiological responses were evident when primed plants were compared to not primed ones, grown under the same saline conditions. SPD priming ameliorated the tolerance towards saline stress, in a genotype-independent manner, by increasing photosynthetic pigments, proline amounts and antioxidant responses in all cultivars exposed to salt. These results may open new perspectives for crop productivity in the struggle against soil salinization.

The intercalations of anionic molecules and drugs in layered double hydroxides (LDHs) have been intensively investigated in recent years. Due to their properties, such as versatility in chemical composition, good biocompatibility, high density and protection of loaded drugs, LDHs seem very promising nanosized systems for drug delivery. In this work, we report the intercalation of S-allyl-mercapto-cysteine (SAMC), which is a component of garlic that is well-known for its anti-tumor properties, inside ZnAl-LDH (hereafter LDH) nanostructured crystals. In order to investigate the efficacy of the intercalation and drug delivery of SAMC, the intercalated compounds were characterized using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The increase in the interlayer distance of LDH from 8.9 Å, typical of the nitrate phase, to 13.9 Å indicated the intercalation of SAMC, which was also confirmed using FT-IR spectra. Indeed, compared to that of the pristine LDH precursor, the spectrum of LDH-SAMC was richly structured in the fingerprint region below 1300 cm−1, whose peaks corresponded to those of the functional groups in the SAMC molecular anion. The LDH-SAMC empirical formula, obtained from UV-Vis spectrophotometry and thermogravimetric analysis, was [Zn0.67Al0.33(OH)2]SAMC0.15(NO3)0.18·0.6H2O. The morphology of the sample was investigated using SEM: LDH-SAMC exhibited a more irregular size and shape of the flake-like crystals in comparison with the pristine LDH, with a reduction in the average crystallite size from 3 µm to about 2 µm. In vitro drug release studies were performed in a phosphate buffer solution at pH 7.2 and 37 °C and were analyzed using UV-Vis spectrophotometry. The SAMC release from LDH-SAMC was initially characterized by a burst effect in the first four hours, during which, 32% of the SAMC is released. Subsequently, the release percentage increased at a slower rate until 42% after 48 h; then it stabilized at 43% and remained constant for the remaining period of the investigation. The LDH-SAMC complex that was developed in this study showed the improved efficacy of the action of SAMC in reducing the invasive capacity of a human hepatoma cell line.

Despite recent advances in immune-modulatory drugs, pharmacological therapies have been proven ineffective in severe presentations of multiple sclerosis (MS), including secondary progressive MS. At present, therapeutic interventions' performance is primarily focused on ameliorating symptoms to improve the patient's quality of life (QOL). Among complementary treatments, nutrition has been considered a decisive factor to control symptoms and enhance the wellness of MS patients. Although no special diets are associated with MS, the impact of diet and dietary supplements on the course of progressive forms of the disease has been studied during the last few years. Fatigue is among the most common and disabling symptoms reported by MS patients. Fatigue has been defined in the Multiple Sclerosis Council for Clinical Practice Guidelines (MSCCPG, 1998) as a "subjective lack of physical and/or mental energy that the individual perceives as an interference with habitual and desired activities". This study aimed to compare the psychometric functioning of the "Fatigue Severity Scale" (FSS) and the "Modified Fatigue Impact Scale" (MFIS) in our sample of people with MS. Specifically, during chronic treatment, the change in these two parameters with two vitamin-rich dietary supplements (Citozym® and Ergozym®) was evaluated. The impact of these nutritional supplements revealed differences in antioxidant and anti-inflammatory parameters among the volunteers in the treatment group, with a subsequent improvement in fatigue. In conclusion, the results obtained have confirmed the effectiveness of complementary nutritional therapies, evaluated essentially based on hematological biomarkers, through which it is possible to act on disability to improve the QOL of MS patients.

Despite recent advances in immune-modulatory drugs, pharmacological therapies have been proven ineffective in severe presentations of multiple sclerosis (MS), including secondary progressive MS. At present, therapeutic interventions' performance is primarily focused on ameliorating symptoms to improve the patient's quality of life. Among complementary treatments, nutrition has been considered a decisive factor to control symptoms and enhance the wellness of MS patients. Although no special diets are associated with MS, the impact of diet and dietary supplements on the course of progressive forms of the disease have been studied during the last years. Fatigue is among the most common and disabling symptoms reported by MS patients. Fatigue has been defined in the Multiple Sclerosis Council for Clinical Practice Guidelines (MSCCPG, 1998) as a "subjective lack of physical and/or mental energy that the individual perceives as an interference with habitual and desired activities". This study aimed to compare the psychometric functioning of the "Fatigue Severity Scale" (FSS) and the "Modified Fatigue Impact Scale" (MFIS) in our sample of people with MS. Specifically, during chronic treatment, the change in these two parameters with two vitamin-rich dietary supplements (Citozym® and Ergozym®) was evaluated. The impact of these nutritional supplements revealed differences in antioxidant and anti-inflammatory parameters between treatment groups with subsequent improvement in fatigue. In conclusion, the results obtained have confirmed the effectiveness of complementary nutritional therapies, evaluated essentially based on hematological biomarkers, through which it is possible to act on disability to improve the quality of life of MS patients.

Among the phenolic acids tested on the K562 cell line, a model of chronic myeloid leukemia (CML), caffeic acid (CA) was biologically active on sensitive and imatinib (IM)-resistant cells at micro-molar concentration, either in terms of reduction of cell proliferation or triggering of apoptosis. The CA treatment provoked mitochondrial membrane depolarization, genomic DNA fragmentation and phosphatidylserine exposure, hallmarks of apoptosis. Cell cycle analysis following the treatment with comparable cytotoxic concentrations of IM or CA showed marked differences in the distribution profiles. The reduction of cell proliferation by CA administration was associated with increased expression of two cell cycle repressor genes, CDKN1A and CHES1, while IM at a cytotoxic concentration increased the CHES1 but not the CDKN1A expression. In addition, CA treatment affected the proliferation and triggered the apoptosis in IM-resistant cells. Taken together, these data suggested that CA induced the anti-proliferative effect and triggered apoptosis of CML cells by a different mechanism than IM. Finally, the combined administration of IM and CA at suboptimal concentrations evidenced a synergy of action in determining the anti-proliferative effect and triggering apoptosis. The ability of CA to potentiate the anti-leukemic effect of IM highlighted the nutraceutical potential of CA in CML.

The beneficial effects of coffee on human diseases are well documented, but the molecular mechanisms of its bioactive compounds on cancer are not completely elucidated. This is likely due to the large heterogeneity of coffee preparations and different coffee-based beverages, but also to the choice of experimental models where proliferation, differentiation and immune responses are differently affected. The aim of the present study was to investigate the effects of one of the most interesting bioactive compounds in coffee, i.e., caffeine, using a cellular model of melanoma at a defined differentiation level. A preliminary in silico analysis carried out on public gene-expression databases identified genes potentially involved in caffeine’s effects and suggested some specific molecular targets, including tyrosinase. Proliferation was investigated in vitro on human melanoma initiating cells (MICs) and cytokine expression was measured in conditioned media. Tyrosinase was revealed as a key player in caffeine’s mechanisms of action, suggesting a crucial role in immunomodulation through the reduction in IL-1β, IP-10, MIP-1α, MIP-1β and RANTES secretion onto MICs conditioned media. The potent antiproliferative effects of caffeine on MICs are likely to occur by promoting melanin production and reducing inflammatory signals’ secretion. These data suggest tyrosinase as a key player mediating the effects of caffeine on melanoma.

Differentiation of a human aggressive PC-3 cancer cell line was obtained, in a previous investigation, by the synergic effect of α-tocopherol (α-TOC) and naringenin (NG). This combined treatment induced apoptosis and subsequent reduction of the PC-3 cell proliferation and invasion, by a pro-differentiating action. Since one of the peculiar characteristics of NG and α-TOC is their strong antioxidant activity, this study aimed to investigate their potential effect on the activity of the main enzymes involved in the antioxidant mechanism in prostate cancer cells. NG and α-TOC administered singularly or combined in the PC-3 cell line, affected the activity of several enzymes biomarkers of the cellular antioxidant activity, as well as the concentration of total glutathione (GSH + GSSG) and thiobarbituric acid reactive substances (TBARS). The combined treatment increased the TBARS levels and superoxide dismutase (SOD) activity, while decreased the glutathione S-transferase (GST), glutathione reductase (GR), and glyoxalase I (GI) activities. The results obtained indicate that a combined treatment with these natural compounds mitigated the oxidative stress in the human PC-3 cell line. In addition, a significant reduction of both ornithine decarboxylase (ODC) expression and intracellular levels of polyamines, both well-known positive regulators of cell proliferation, accompanied the reduction of oxidative stress observed in the combined α-TOC and NG treatment. Considering the established role of polyamines in cell differentiation, the synergism with NG makes α-TOC a potential drug for further study on the differentiation therapy in prostate cancer patients.

Nutraceuticals are biologically active molecules present in foods; they can have beneficial effects on health, but they are not available in large enough quantities to perform this function. Plant metabolites, such as polyphenols, are widely diffused in the plant kingdom, where they play fundamental roles in plant development and interactions with the environment. Among these, flavonoids are of particular interest as they have significant effects on human health. In vitro and/or in vivo studies described flavonoids as essential nutrients for preventing several diseases. They display broad and promising bioactivities to fight cancer, inflammation, bacterial infections, as well as to reduce the severity of neurodegenerative and cardiovascular diseases or diabetes. Therefore, it is not surprising that interest in flavonoids has sharply increased in recent years. More than 23,000 scientific publications on flavonoids have described the potential anticancer activity of these natural molecules in the last decade. Studies, in vitro and in vivo, show that flavonoids exhibit anticancer properties, and many epidemiological studies confirm that dietary intake of flavonoids leads to a reduced risk of cancer. This review provides a glimpse of the mechanisms of action of flavonoids on cancer cells.

In an in vitro Ca2+-induced cataract model, the progression of opacification is paralleled by a rapid decrease of the endogenous levels of spermidine (SPD) and an increase of transglutaminase type 2 (TG2, EC 2.3.2.13)-catalyzed lens crystallins cross-linking by protein-bound N1-N8-bis(γ-glutamyl) SPD. This pattern was reversed adding exogenous SPD to the incubation resulting in a delayed loss of transparency of the rabbit lens. The present report shows evidence on the main incorporation of SPD by the catalytic activity of TG2, toward βH-crystallins and in particular to the βB2- and mostly in βB3-crystallins. The increase of endogenous SPD in the cultured rabbit lens showed the activation of a flavin adenine dinucleotide (FAD)-dependent polyamine oxidases (PAO EC 1.5.3.11). As it is known that FAD-PAO degrades the N8-terminal reactive portion of N1-mono(γ-glutamyl) SPD, the protein-bound N8-mono(γ-glutamyl) SPD was found the mainly available derivative for the potential formation of βB3-crystallins cross-links by protein-bound N1-N8-bis(γ-glutamyl)SPD. In conclusion, FAD-PAO degradation of the N8-terminal reactive residue of the crystallins bound N1-mono(γ-glutamyl)SPD together with the increased concentration of exogenous SPD, leading to saturation of glutamine residues on the substrate proteins, drastically reduces N1-N8-bis(γ-glutamyl)SPD crosslinks formation, preventing crystallins polymerization and avoiding rabbit lens opacification. The ability of SPD and MDL 72527 to modulate the activities of TG2 and FAD-PAO involved in the mechanism of lens opacification suggests a potential strategy for the prevention of senile cataract.

One area of research currently garnering significant attention is the in-depth study of cancer cell metabolism. The purpose of this research is not exclusively to discover new anticancer therapies, but rather to improve the quality of life of the patient. Many cancer patients suffer from a muscle wasting syndrome called cachexia. Cancer related cachexia impairs quality of life and response to therapy, which increases morbidity and mortality among cancer patients. The data presented in this report were collected to address disorders caused by therapies aimed at reducing tumor growth. Carbohydrate metabolism is the major pathway in the cell providing energy and building blocks for macromolecule biosynthesis. Glucose metabolism in cancerous cells is remarkably different from that in their normal counterparts. The purpose of this research was to investigate the effects on energy metabolism in normal and neoplastic cells of the various components of the dietary supplement Texidrofolico (TXF), which act on their cellular enzymatic complexes. Treatment of HepG2 tumor cells with TXF reduces glucose consumption, and slows reduction of pyruvate to lactate, following indirect inhibition of lactate dehydrogenase (LDH) by blocking regeneration of NAD+ from NADH. These activities inhibit glycolysis, with consequent reduction in energy yield, evidenced by an increased ADP/ATP ratio. By contrast, in normal MEF cells treated with TXF, the ADP/ATP ratio was observed to be lower than in untreated control cells, showing increased energy relative to untreated normal cells. The observed effects seem to be due to the presence of two active components in TXF: folic acid, and pyruvate. Calciferol, which exerts less influence on glucose consumption, instead shows some inhibition of LDH reductase activity.