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The aim of this study was to evaluate the antidiabetic potential of a leaf extract and flavonoids from Sedum dendroideum (SD). Additionally, our goals were to establish a possible structure/activity relationship between these flavonoids and to assess the most active flavonoid on the glycolytic enzyme 6-phosphofructo-1-kinase (PFK). SD juice (LJ), a flavonoid-rich fraction (BF), and separately five flavonoids were evaluated intraperitoneally for their acute hypoglycemic activity in normal and streptozotocin-induced diabetic mice. First, the major flavonoids kaempferol 3,7-dirhamnoside or kaempferitrin (1), kaempferol 3-glucoside-7-rhamnoside (2), and kaempferol 3-neohesperidoside-7-rhamnoside (3) were tested. Then, the monoglycosides kaempferol 7-rhamnoside (5) and kaempferol 3-rhamnoside (6) were assayed to establish their structure/activity relationship. The effect of 1 on PFK was evaluated in skeletal muscle, liver, and adipose tissue from treated mice. LJ (400 mg/kg), BF (40 mg/kg), and flavonoid 1 (4 mg/kg) reduced glycemia in diabetic mice (120 min) by 52, 53, and 61%, respectively. Flavonoids 2, 3, 5, and 6 were inactive or showed little activity, suggesting that the two rhamnosyl moieties in kaempferitrin are important requirements. Kaempferitrin enhanced the PFK activity chiefly in hepatic tissue, suggesting that it is able to stimulate tissue glucose utilization. This result is confirmed testing kaempferitrin on C2C12 cell line, where it enhanced glucose consumption, lactate production, and the key regulatory glycolytic enzymes. The hypoglycemic activity of kaempferitrin depends on the presence of both rhamnosyl residues in the flavonoid structure when intraperitoneally administered. Our findings show for the first time that a flavonoid is capable of stimulating PFK in a model of diabetes and that kaempferitrin stimulates glucose-metabolizing enzymes. This study contributes to the knowledge of the mechanisms by which this flavonoid exerts its hypoglycemic activity. © 2014 IUBMB Life, 66(5):361-370, 2014 [ABSTRACT FROM AUTHOR]

Examines the protection against thermal denaturation by trehalose on the plasma membrane H[sup +]-adenosine triphosphatase from yeast. Details on synergetic effects between sugar and lipids.

Mycobacterium leprae, the intracellular etiological agent of leprosy, infects Schwann promoting irreversible physical disabilities and deformities. These cells are responsible for myelination and maintenance of axonal energy metabolism through export of metabolites, such as lactate and pyruvate. In the present work, we observed that infected Schwann cells increase glucose uptake with a concomitant increase in glucose-6-phosphate dehydrogenase (G6PDH) activity, the key enzyme of the oxidative pentose pathway. We also observed a mitochondria shutdown in infected cells and mitochondrial swelling in pure neural leprosy nerves. The classic Warburg effect described in macrophages infected by Mycobacterium avium was not observed in our model, which presented a drastic reduction in lactate generation and release by infected Schwann cells. This effect was followed by a decrease in lactate dehydrogenase isoform M (LDH-M) activity and an increase in cellular protection against hydrogen peroxide insult in a pentose phosphate pathway and GSH-dependent manner. M. leprae infection success was also dependent of the glutathione antioxidant system and its main reducing power source, the pentose pathway, as demonstrated by a 50 and 70% drop in intracellular viability after treatment with the GSH synthesis inhibitor buthionine sulfoximine, and aminonicotinamide (6-ANAM), an inhibitor of G6PDH 6-ANAM, respectively. We concluded that M. leprae could modulate host cell glucose metabolism to increase the cellular reducing power generation, facilitating glutathione regeneration and consequently free-radical control. The impact of this regulation in leprosy neuropathy is discussed. [ABSTRACT FROM AUTHOR]

Abstract: Since its discovery the therapeutic use of the pancreatic hormone amylin has been limited due to its poor water solubility and propensity for amyloid aggregation. We have entrapped the human amylin protein in polymeric nanoparticles, using a single emulsion–solvent evaporation method and investigated its effectiveness in the controlled release of the peptide. Typical preparations composed of poly-ɛ-caprolactone had a mean particle size of approximately 200nm, low polydispersity index, high protein entrapment efficiency (80%) and process yield (90%), and spherical and smooth surfaces. These nanoparticles presented a controlled release in vitro for approximately 240h. Pharmacological evaluation in vivo by subcutaneous administration in fasting mice demonstrated the bioactivity and effectiveness of the released human amylin, resulting in reduced glycemia lasting for at least 36h. These features indicate the potential for the use of a confined particulate system in the therapeutic controlled and sustained release of human amylin. [Copyright &y& Elsevier]

Citrate is widely used as a food additive being part of virtually all processed foods. Although considered inert by most of the regulatory agencies in the world, plasma citrate has been proposed to play immunometabolic functions in multiple tissues through altering a plethora of cellular pathways. Here, we used a short-term alimentary intervention (24 hours) with standard chow supplemented with citrate in amount corresponding to that found in processed foods to evaluate its effects on glucose homeostasis and liver physiology in C57BL/6J mice. Animals supplemented with dietary citrate showed glucose intolerance and insulin resistance as revealed by glucose and insulin tolerance tests. Moreover, animals supplemented with citrate in their food displayed fed and fasted hyperinsulinemia and enhanced insulin secretion during an oral glucose tolerance test. Citrate treatment also amplified glucose-induced insulin secretion in vitro in INS1-E cells. Citrate supplemented animals had increased liver PKCα activity and altered phosphorylation at serine or threonine residues of components of insulin signaling including IRS-1, Akt, GSK-3 and FoxO1. Furthermore, citrate supplementation enhanced the hepatic expression of lipogenic genes suggesting increased de novo lipogenesis, a finding that was reproduced after citrate treatment of hepatic FAO cells. Finally, liver inflammation markers were higher in citrate supplemented animals. Overall, the results demonstrate that dietary citrate supplementation in mice causes hyperinsulinemia and insulin resistance both in vivo and in vitro, and therefore call for a note of caution on the use of citrate as a food additive given its potential role in metabolic dysregulation. [ABSTRACT FROM AUTHOR]

The immune system is a key component of tumorigenesis, with the latter promoting the development of cancer, its progression and metastasis. In fact, abundant infiltration of tumor-associated macrophages (TAM), which are M2-like macrophages, has been associated with a poor outcome in most types of cancers. Here, we show that lactate produced by murine melanoma B16F10 cells induces an M2-like profile in cultured macrophages. Further, we demonstrate that clotrimazole (CTZ), an off-target anti-tumor drug, abolishes lactate effects on the activation of macrophages and induces the expression of M1-like markers. We show that clotrimazole has cytotoxic effects on tumor cells by negatively modulating PI3K, which inhibits glycolytic metabolism and leads to a diminishing lactate production by these cells. These effects are more pronounced in cancer cells exposed to conditioned media of M2-polarized macrophages. Moreover, clotrimazole inhibits tumor growth in a murine model of implanted melanoma, reduces lactate content in a tumor microenvironment and decreases vascular endothelial growth factor expression. Finally, clotrimazole drastically diminishes TAM infiltration in the tumors, thereby inducing M1 polarization. Collectively, these findings identify a new antitumor mechanism of clotrimazole by modulating the tumor microenvironment (TME), particularly the activation and viability of TAM. [Display omitted] • CTZ decreases tumor growth, macrophage infiltration and induces pro-inflammatory phenotype in tumor-resident macrophages. • CTZ inhibits PI3K in B16F10 cells inducing cell death. • CTZ promotes TAM repolarization to M1 activation profile. • CTZ is more cytotoxic to M2-polarized macrophages as compared to M1-polarized. [ABSTRACT FROM AUTHOR]

AMPK plays a critical role regulating cell metabolism, growth and survival. Interfering with this enzyme activity has been extensively studied as putative mechanism for cancer therapy. The present work aims to identify a specific AMPK activator for cancer cells among a series of novel heterocyclic compounds. A series of novel hybrid heterocyclic compounds, namely naphtoquinone-4-oxoquinoline and isoquinoline-5,8-quinone-4-oxoquinoline derivatives, were synthesized via Michael reaction and their structures confirmed by spectral data: infrared; 1H and 13C NMR spectroscopy (COSY, HSQC, HMBC); and high-resolution mass spectrometry (HRMS). The novel compounds were screened and tested for antitumoral activity and have part of their mechanism of action scrutinized. Here, we identified a selective AMPK activator among the new hybrid heterocyclic compounds. This new compound presents selective cytotoxicity on breast cancer cells but not on non-cancer counterparts. We identified that by specifically activating AMPK in cancer cells, the drug downregulates unfolded protein response pathway, as well as inhibits mTOR signaling. These effects, that are selective for cancer cells, lead to activation of autophagy and, ultimately, to cancer cells death. Taken together, our data support the promising anticancer activity of this novel compound which is a strong modulator of metabolism. [Display omitted] • A selective AMPK activator was identified among naphtoquinone-4-oxoquinoline and isoquinoline-5,8-quinone-4-oxoquinoline derivatives • The new drug actives AMPK in breast cancer cells but not in their non-cancer counterpart • As a consequence of AMPK activation, the new drug downregulates unfolded protein response pathway • AMPK activation and UPR downregulation selectively increases cancer cells death and autophagy [ABSTRACT FROM AUTHOR]

Melanoma is the most aggressive and fatal type of skin cancer due to being highly proliferative. Acetylsalicylic acid (ASA; Aspirin) and salicylic acid (SA) are ancient drugs with multiple applications in medicine. Here, we showed that ASA and SA present anticancer effects against a murine model of implanted melanoma. These effects were also validated in 3D- and 2D-cultured melanoma B16F10 cells, where the drugs promoted pro-apoptotic effects. In both in vivo and in vitro models, SA and ASA triggered endoplasmic reticulum (ER) stress, which culminates with the upregulation of the pro-apoptotic transcription factor C/EBP homologous protein (CHOP). These effects are initiated by ASA/SA-triggered Akt/mTOR/AMPK-dependent activation of nitric oxide synthase 3 (eNOS), which increases nitric oxide and reactive oxygen species production inducing ER stress response. In the end, we propose that ASA and SA instigate anticancer effects by a novel mechanism, the activation of ER stress. [ABSTRACT FROM AUTHOR]

The search for novel anticancer drugs is essential to expand treatment options, overcome drug resistance, reduce toxicity, promote innovation, and tackle the economic impact. The importance of these studies lies in their contribution to advancing cancer research and enhancing patient outcomes in the battle against cancer. Here, we developed new asymmetric hybrids containing two different naphthoquinones linked by a 1,2,3-1H-triazole nucleus, which are potential new drugs for cancer treatment. The antitumor activity of the novel compounds was tested using the breast cancer cell lines MCF-7 and MDA-MB-231, using the non-cancer cell line MCF10A as control. Our results showed that two out of twenty-two substances tested presented potential antitumor activity against the breast cancer cell lines. These potential drugs, named here 12g and 12h were effective in reducing cell viability and promoting cell death of the tumor cell lines, exhibiting minimal effects on the control cell line. The mechanism of action of the novel drugs was assessed revealing that both drugs increased reactive oxygen species production with consequent activation of the AMPK pathway. Therefore, we concluded that 12g and 12h are novel AMPK activators presenting selective antitumor effects., Competing Interests: Declaration of competing interest Fellowships granted by CNPq, CAPES and FAPERJ are gratefully acknowledged. This work was partially supported by CNPq, grant numbers 306011/2020-4 and 404587/2021-6, CAPES, financial code 001, and FAPERJ, grant numbers E-26/200.870/2021 and E-26/211.343/2021., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Leprosy is a chronic infectious disease caused by the intracellular bacillus Mycobacterium leprae (M. leprae), which is known to infect skin macrophages and Schwann cells. Although adipose tissue is a recognized site of Mycobacterium tuberculosis infection, its role in the histopathology of leprosy was, until now, unknown. We analyzed the M. leprae capacity to infect and persist inside adipocytes, characterizing the induction of a lipolytic phenotype in adipocytes, as well as the effect of these infected cells on macrophage recruitment. We evaluated 3T3-L1-derived adipocytes, inguinal adipose tissue of SWR/J mice, and subcutaneous adipose tissue biopsies of leprosy patients. M. leprae was able to infect 3T3-L1-derived adipocytes in vitro, presenting a strong lipolytic profile after infection, followed by significant cholesterol efflux. This lipolytic phenotype was replicated in vivo by M. leprae injection into mice inguinal adipose tissue. Furthermore, M. leprae was detected inside crown-like structures in the subcutaneous adipose tissue of multibacillary patients. These data indicate that subcutaneous adipose tissue could be an important site of infection, and probably persistence, for M. leprae, being involved in the modulation of the innate immune control in leprosy via the release of cholesterol, MCP-1, and adiponectin., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.)

Macrophages switch among different activation phenotypes according to distinct environmental stimuli, varying from pro-inflammatory (M1) to alternative (also named resolutive; M2) activation forms. M1-and M2-activated macrophages represent the two extremes of the activation spectrum involving multiple species, which vary in terms of function and the cytokines secreted. The consensus is that molecular characterization of the distinct macrophage population and the signals driving their activation will help in explaining disease etiology and formulating therapies. For instance, myeloid cells residing in the tumor microenvironment are key players in tumor progression and usually display an M2-like phenotype, which help tumor cells to evade local inflammatory processes. Therefore, these specific cells have been proposed as targets for tumor therapies by changing their activation profile. Furthermore, M2 polarized macrophages are phagocytic cells promoting tissue repair and wound healing and are therefore potential targets to treat different diseases. We have already shown that clotrimazole (CTZ) decreases tumor cell viability and thus tumor growth. The mechanism by which CTZ exerts its effects remains to be determined, but this drug is an inhibitor of the PI3K/AKT/mTOR pathway. In this study, we show that CTZ downregulated M2-activation markers in macrophages polarized to the M2 profile. This effect occurred without interfering with the expression of M1-polarized markers or pro-inflammatory cytokines and signaling. Moreover, CTZ suppressed NFkB pathway intermediates and disrupted PI3K/AKT/mTOR signaling. We concluded that CTZ reverses macrophage M2 polarization by disrupting the PI3K/AKT/mTOR pathway, which results in the suppression of NFkB induction of M2 polarization. In addition, we find that CTZ represents a promising therapeutic tool as an antitumor agent., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The high prevalence of metabolic syndrome in low- and middle-income countries is linked to an increase in Western diet consumption, characterized by a high intake of processed foods, which impacts the levels of blood sugar and lipids, hormones, and cytokines. Hematophagous insect vectors, such as the yellow fever mosquito Aedes aegypti, rely on blood meals for reproduction and development and are therefore exposed to the components of blood plasma. However, the impact of the alteration of blood composition due to malnutrition and metabolic conditions on mosquito biology remains understudied., Methods: In this study, we investigated the impact of whole-blood alterations resulting from a Western-type diet on the biology of Ae. aegypti. We kept C57Bl6/J mice on a high-fat, high-sucrose (HFHS) diet for 20 weeks and followed biological parameters, including plasma insulin and lipid levels, insulin tolerance, and weight gain, to validate the development of metabolic syndrome. We further allowed Ae. aegypti mosquitoes to feed on mice and tracked how altered host blood composition modulated parameters of vector capacity., Results: Our findings identified that HFHS-fed mice resulted in reduced mosquito longevity and increased fecundity upon mosquito feeding, which correlated with alteration in the gene expression profile of nutrient sensing and physiological and metabolic markers as studied up to several days after blood ingestion., Conclusions: Our study provides new insights into the overall effect of alterations of blood components on mosquito biology and its implications for the transmission of infectious diseases in conditions where the frequency of Western diet-induced metabolic syndromes is becoming more frequent. These findings highlight the importance of addressing metabolic health to further understand the spread of mosquito-borne illnesses in endemic areas., (© 2024. The Author(s).)

Diet-induced obesity triggers elevation of circulating pro-inflammatory cytokines and acute-phase proteins, including interferons (IFNs). IFNs strongly contribute to low-grade inflammation associated with obesity-related complications, such as nonalcoholic fat liver disease and diabetes. In this study, AG129 mice model (double-knockout strain for IFN α/β/γ receptors) was fed with a high-fat high-sucrose (HFHS) diet (Western diet) for 20 weeks aiming to understand the impact of IFN receptor ablation on diet-induced obesity, insulin resistance, and nonalcoholic fat liver disease. Mice were responsive to the diet, becoming obese after 20 weeks of HFHS diet which was accompanied by 2-fold increase of white adipose tissues. Moreover, animals developed glucose and insulin intolerance, as well as dysregulation of insulin signaling mediators such as Insulin Receptor Substrate 1 (IRS1), protein kinase B (AKT), and S6 ribosomal protein. Liver increased interstitial cells, and lipid accumulation was also found, presenting augmented fibrotic markers (transforming growth factor beta 1 [Tgfb1], Keratin 18 [Krt18], Vimentin [Vim]), yet lower expression on IFN receptor downstream proteins (Toll-like receptor [TLR] 4, nuclear factor kappa-light-chain-enhancer of activated B cells [NFκB], and cAMP response element-binding protein [CREB]). Thus, IFN receptor ablation promoted effects on NFκB and CREB pathways, with no positive effects on systemic homeostasis in diet-induced obese mice. Therefore, we conclude that IFN receptor signaling is not essential for promoting the complications of diet-induced obesity and thus cannot be correlated with metabolic diseases in a noninfectious condition.

The Western diet (high in fat and sucrose) consumption is a highly prevalent feature in the whole world, mainly due to the increasing consumption of ultra-processed foods (UPF), which are cheaper and easier-to-eat, as compared to fresh and highly nutritive meals. Epidemiological studies have associated UPF consumption with development of obesity, non-alcoholic fat liver disease (NAFLD) and insulin resistance. For molecular studies, mice fed with Western diets have been used to characterize signaling pathways involved in these diet-induced pathologies. However, these studies fed mice continuously with the diets, which is not compatible with what occurs in real life, when consumption is occasional. Here, we fed mice once-a-week with a high fat, high sucrose (HFHS) diet and compared these animals with those fed continuously with HFHS diet or with a standard diet. Our results show that after a single day of consuming HFHS, animals presented impaired oral glucose tolerance test (oGTT) as compared to control group. Although this impairment was reversed after 24 h consuming regular diet, repetition of HFHS consumption once-a-week aggravated the picture such as after 12-weeks, oGTT impairment was not reversed after 6 days under control diet. Liver steatosis, inflammation, impaired insulin signaling pathway and endoplasmic reticulum stress are similar comparing animals that consumed HFHS once-a-week with those that continuously consumed HFHS, though weekly-fed animals did not gain as much weight. Therefore, we conclude that regimen of one day HFHS plus 6 days normal diet over 12 weeks is sufficient to induce insulin resistance and NAFLD in mice., (© 2023. The Author(s).)

Citrate, a major component of processed foods, appears as either preservative or flavor enhancer. With no concentration limit, citrate is consumed in large quantities worldwide, principally in ultra-processed foods (UPF). UPF are encountered in Western diets (rich in saturated fat and sucrose), where consumption is directly associated with many conditions, such as obesity and diabetes, among others. Here, we administered a High-Fat, High-Sucrose (HFHS) diet to mice, enriched or not with citrate (67 mg g -1 diet), aimed to simulate UPF citrate consumption. Our results showed that citrate enrichment prevented the HFHS-induced lipid deposition in the liver and adipose tissues of the animals. Moreover, the treatment induced mitochondrial biogenesis in white adipose tissues, via upregulation of PCG1α. As a result, citrate enhancement upregulated UCP1, suggesting the browning of white adipose tissues. Nevertheless, the citrate-enhanced diet did not prevent HFHS-induced insulin resistance and causes further liver inflammation and injury. Altogether, our results clearly showed that, associated to UPF consumption, the excess of dietary citrate has caused harmful effects being associated to non-obesity related liver inflammatory diseases and insulin resistance.

Objective: Inducible nitric oxide (NO) synthase (NOS2) is a well-documented inflammatory mediator of insulin resistance in obesity. NOS2 expression is induced in both adipocytes and macrophages within adipose tissue during high-fat (HF)-induced obesity., Methods: Eight-week-old male mice with adipocyte selective deletion of the Nos2 gene (Nos2 AD-KO ) and their wildtype littermates (Nos2 fl/fl ) were subjected to chow or high-fat high-sucrose (HFHS) diet for 10 weeks followed by metabolic phenotyping and determination of brown adipose tissue (BAT) thermogenesis. The direct impact of NO on BAT mitochondrial respiration was also assessed in brown adipocytes., Results: HFHS-fed Nos2 AD-KO mice had improved insulin sensitivity as compared to Nos2 fl/fl littermates. Nos2 AD-KO mice were also protected from HF-induced dyslipidemia and exhibited increased energy expenditure compared with Nos2 fl/fl mice. This was linked to the activation of BAT in HFHS-fed Nos2 AD-KO mice as shown by increased Ucp1 and Ucp2 gene expression and augmented respiratory capacity of BAT mitochondria. Furthermore, mitochondrial respiration was inhibited by NO, or upon cytokine-induced NOS2 activation, but improved by NOS2 inhibition in brown adipocytes., Conclusions: These results demonstrate the key role of adipocyte NOS2 in the development of obesity-linked insulin resistance and dyslipidemia, partly through NO-dependent inhibition of BAT mitochondrial bioenergetics., (Copyright © 2022 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Among the principal causative factors for the development of complications related to aging is a diet rich in fats and sugars, also known as the Western diet. This diet advocates numerous changes that might increase the susceptibility to initiate cancer and/or to create a tissue microenvironment more conducive to the growth of malignant cells, thus favoring the progression of cancer and metastasis. Hypercaloric diets in general lead to oxidative stress generating reactive oxygen species and induce endoplasmic reticulum stress. Our results demonstrate that mice bearing tumors fed with a Western diet presented bigger tumor mass with increased insulin sensitivity in these tissues. Several markers of insulin signaling, such as AKT phosphorylation and mTOR pathway, are promoted in tumors of Western diet-fed animals. This process is associated with increased macrophage infiltration, activation of unfolded protein response pathway, and initiation of epithelial-mesenchymal transition (EMT) process in these tumor tissues. Summing up, we propose that the Western diet accelerates the aging-related processes favoring tumor development.

Background: Although produced by several types of tumours, the role of serotonin on cancer biology is yet to be understood., Methods: The effects of serotonin (5-HT) on human breast cancer cells proliferation, signalling pathways and metabolic profile were evaluated by cytometry, western blotting, qPCR, enzymology and confocal microscopy., Results: Our results revealed that incubation of MCF-7 cells with 10 µM 5-HT increased cell growth rate by 28%, an effect that was prevented by the 5-HTR 2A/C antagonist, ketanserin. Conversely, increasing concentrations of 5-HT promoted glucose consumption and lactate production by MCF-7 cells. We also showed that increased glucose metabolism is provoked by the upregulation of pyruvate kinase M2 (PKM2) isoform through 5-HTR 2A/C -triggered activation of Jak1/STAT3 and ERK1/2 subcellular pathways. However, we noticed a decrease in the rate of produced lactate per consumed glucose as a function of the hormone concentration, suggesting a disruption of the Warburg effect. The latter effect is due to 5-HTR 2A/C -dependent mitochondrial biogenesis and metabolism, which is triggered by adenylyl cyclase/PKA, enhancing the oxidation of lactate within these cells., Conclusions: We showed that serotonin, through 5-HTR 2A/C , interferes with breast cancer cells proliferation and metabolism by triggering two distinct signalling pathways: Jak1/STAT3 that boosts glycolysis through upregulation of PKM2, and adenylyl cyclase/PKA that enhances mitochondrial biogenesis.

Phosphofructokinase (PFK) is a key regulatory enzyme of glycolysis, being considered the pacemaker of this pathway. In mammals, this enzyme exists as three different isoforms, PFKM, PFKL and PFKP, presenting different regulatory and catalytic properties. The expression of these isoforms is tissue-specific and vary according to the cell differentiation and signalization. Although it is known that the expression of the different PFK isoforms directly affects cell function, the information regarding the regulation of PFK isoforms expression is scarce. In the present work, we evaluate the role of insulin signalization on the expression of three PFK isoforms on skeletal muscle, liver, and epididymal white adipose tissue (eWAT) of mice. For this, Swiss mice were treated with streptozotocin (STZ) to disrupt pancreatic ß-cells and, thus, insulin production. Control group were treated with citrate buffer (STZ vehicle). These groups were then treated with insulin or saline twice a day for ten consecutive days when animals were euthanized and tissues used for the evaluation of PFK isoforms expression by quantitative PCR (qPCR). Our results revealed that the lack of insulin significantly impacted the expression of PFKL, presenting mild effects on PFKM and no effects on PFKP. The decrease of PFKL and PFKM mRNA levels observed on the group treated with STZ was reversed by the treatment with insulin. In conclusion, insulin, the most known regulator of glucose consumption, specifically regulates the expression of PFKL and PFKM, which impact the regulation of glycolysis in the cell., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Breast cancer is the major cause of death by cancer in women worldwide and in spite of the many drugs for its treatment, there is still the need for novel therapies for its control. Ocimum species have been used by traditional medicine to control several diseases, including cancer. We have previously characterized the antidiabetic properties of the unfractionated aqueous leaf extracts of Ocimum basilicum (OB) and Ocimum gratissimum (OG), modulating glucose metabolism in diabetic mice. Since glucose metabolism is primordial for cancer cells survival, we hypothesized that these extracts are effective against cancer cells. The unfractionated aqueous leaf extracts of OB and OG were chemically characterized and tested for their cytotoxic, cytostatic and anti-proliferative properties against the human breast cancer cell line MCF-7. Both extracts presented cytostatic effects with an 80% decrease in MCF-7 cell growth at 1 mg/mL. However, only OB promoted cytotoxic effects, interfering with the cell viability even after interruption of the treatment. Moreover, OB but not OG affected the cell proliferation and metabolism, evaluated in terms of lactate production and intracellular ATP content. After 24 h of treatment, OB treated cells presented an apoptotic profile, while OG treated cells were more necrotic. The treatment with both extracts also activated AMPK, but OB was much more efficient than OG in promoting this. The activation of mTOR signaling, another survival pathway was promoted by OB, whereas OG failed to activate it. In the end, we conclude that OB extract is efficient against the human breast cancer cell line.

The aim of this study was to evaluate the antidiabetic potential of a leaf extract and flavonoids from Sedum dendroideum (SD). Additionally, our goals were to establish a possible structure/activity relationship between these flavonoids and to assess the most active flavonoid on the glycolytic enzyme 6-phosphofructo-1-kinase (PFK). SD juice (LJ), a flavonoid-rich fraction (BF), and separately five flavonoids were evaluated intraperitoneally for their acute hypoglycemic activity in normal and streptozotocin-induced diabetic mice. First, the major flavonoids kaempferol 3,7-dirhamnoside or kaempferitrin (1), kaempferol 3-glucoside-7-rhamnoside (2), and kaempferol 3-neohesperidoside-7-rhamnoside (3) were tested. Then, the monoglycosides kaempferol 7-rhamnoside (5) and kaempferol 3-rhamnoside (6) were assayed to establish their structure/activity relationship. The effect of 1 on PFK was evaluated in skeletal muscle, liver, and adipose tissue from treated mice. LJ (400 mg/kg), BF (40 mg/kg), and flavonoid 1 (4 mg/kg) reduced glycemia in diabetic mice (120 min) by 52, 53, and 61%, respectively. Flavonoids 2, 3, 5, and 6 were inactive or showed little activity, suggesting that the two rhamnosyl moieties in kaempferitrin are important requirements. Kaempferitrin enhanced the PFK activity chiefly in hepatic tissue, suggesting that it is able to stimulate tissue glucose utilization. This result is confirmed testing kaempferitrin on C2C12 cell line, where it enhanced glucose consumption, lactate production, and the key regulatory glycolytic enzymes. The hypoglycemic activity of kaempferitrin depends on the presence of both rhamnosyl residues in the flavonoid structure when intraperitoneally administered. Our findings show for the first time that a flavonoid is capable of stimulating PFK in a model of diabetes and that kaempferitrin stimulates glucose-metabolizing enzymes. This study contributes to the knowledge of the mechanisms by which this flavonoid exerts its hypoglycemic activity., (© 2014 International Union of Biochemistry and Molecular Biology.)

The treatment of Diabetes Mellitus (DM), a chronic disease, is primarily based upon administration of insulin forms to patients. Conventional subcutaneous administration is associated with a large number of complications, therefore, several new strategies have been developed. Amongst these strategies, oral insulin administration is much less invasive and, therefore, well tolerated. In recent years, various nanoformulations were developed for the oral administration of insulin, allowing more effective stabilization of the active pharmaceutical ingredient and modified for better absorption along the gastrointestinal tract. The development of different oral insulin nanoformulations in academic research as well as in patents, including the development of nanoparticles, liposomes, nanoemulsions and the use of cyclodextrins deserves special attention. The future of oral insulin nanoformulations is dependent on strategies utilizing simple technologies that stabilize the raw material, including inclusion within cyclodextrins or inclusion in low weight molecular mass polymers/ oligomers. All of the theories developed here provide a solid foundation upon which to develop new methods for the production of pharmaceutical peptide formulations. In addition, the effective search for existing nanometric formulations of insulin could provide economically viable therapeutic options that can consequently be produced on an industrial scale.

Pseudallescheria boydii is a filamentous fungus that causes a wide array of infections that can affect practically all the organs of the human body. The treatment of pseudallescheriosis is difficult since P. boydii exhibits intrinsic resistance to the majority of antifungal drugs used in the clinic and the virulence attributes expressed by this fungus are unknown. The study of the secretion of molecules is an important approach for understanding the pathogenicity of fungi. With this task in mind, we have shown that mycelial cells of P. boydii were able to actively secrete proteins into the extracellular environment; some of them were recognized by antibodies present in the serum of a patient with pseudallescheriosis. Additionally, molecules secreted by P. boydii induced in vitro irreversible damage in pulmonary epithelial cells. Subsequently, two-dimensional gel electrophoresis combined with mass spectrometry was carried out in order to start the construction of a map of secreted proteins from P. boydii mycelial cells. The two-dimensional map showed that most of the proteins (around 100 spots) were focused at pH ranging from 4 to 7 with molecular masses ranging from 14 to >117 kDa. Fifty spots were randomly selected, of which 30 (60%) were consistently identified, while 20 (40%) spots generated peptides that showed no resemblance to any known protein from other fungi and/or MS with low quality. Notably, we identified proteins involved in metabolic pathways (energy/carbohydrate, nucleotide, and fatty acid), cell wall remodeling, RNA processing, signaling, protein degradation/nutrition, translation machinery, drug elimination and/or detoxification, protection against environmental stress, cytoskeleton/movement proteins, and immunogenic molecules. Since the genome of this fungus is not sequenced, we performed enzymatic and immunodetection assays in order to corroborate the presence of some released proteins. The identification of proteins actively secreted by P. boydii provides important new information for understanding immune modulation and provides important new perspectives on the biology of this intriguing fungus.