Paula García

Microencapsulation of pulp and ultrafiltered cactus pear (Opuntia ficus-indica) extracts and betanin stability during storage.

Pulp (CP) and ultrafiltered (UF) cactus pear extracts were encapsulated with Capsul (C) by applying a central composite design (CP-C and UF-C systems) by spray-drying. To evaluate the effect of the extract, microparticles obtained under optimal conditions were characterised and stored at 60 °C. Betacyanin and betaxanthin encapsulation efficiency reached values above 98% for both systems studied. This efficiency was attributed to strong interactions between betalains and the polymer. Betalain degradation in CP-C and UF-C microparticles followed pseudo-first order kinetics. The betacyanin degradation rate constant was significantly higher for CP-C than for UF-C. These results suggested that the mucilage or higher sugar content of CP increased the hygroscopicity of the CP-C microparticles, leading to the degradation of betalain. The hydrolysis pathway was the main mechanism of betanin degradation during microparticle storage. These results demonstrate the potential utility of both CP-C and UF-C microparticles as natural colourants for healthy foods.

Thermal stability of oils added with avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) leaf extracts during the French potatoes frying

Effect of the addition of avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) hydroalcoholic leaf extracts (AHE and OHE, respectively) on thermal stability of canola oil (CO) and high oleic sunflower oil (HOSO) during French potatoes frying at 180°C was studied. The extracts were characterized by the total phenolic content, phenol chromatographic profiles and antioxidant activity. B-type trimer procyanidins were the major phenolic compounds identified in AHE. OHE showed higher phenol content, antioxidant activity regarding AHE. CO+OHE and HOSO+OHE decreased the formation of polar compounds and showed an anti-polymeric effect with respect to oils without extracts, whereas AHE extract showed a prooxidant effect on HOSO. Therefore, OHE showed an antioxidant effect on HOSO and CO under the studied conditions. In addition, all systems (CO+AHE, HOSO+AHE, CO+OHE and HOSO+OHE) increased the retention of tocopherols. These results demonstrate the potential utility of OHE as natural antioxidant for oils.

Release kinetics of flavonoids in methyl linoleate from microparticles designed with inulin and channelizing agent

Quercetin (Q), naringenin (N) and epicatechin (E) were encapsulated with inulin (In) as encapsulating agent and Capsul (C) as channelizing agent by spray drying and applying a Box-Behnken design. Q-In, N-In, E-In, Q-In-C, N-In-C and E-In-C were characterised by encapsulating efficiency (EE) and their release profile in methyl linoleate (ML). The flavonoid EE was significant higher (p<0.05) for Q and E (over 60%) than for N (≈40%) in microparticles either without or with channelizing agent. An increase of the number of flavonoid hydroxyl groups enhanced EE, showing the influence of the flavonoid structural features. The release profile was fitted to Peppas and Higuchi mathematical models. The highest and lowest flavonoid release rate constants were found for N and E, respectively, for microparticles both with and without channelizing agent. The EE as indicator of flavonoid-inulin interaction was inversely related with the release rate constant in ML. Flavonoid release rate constant was significantly higher for microparticles with channelizing agent than for those without it, suggesting that Capsul induces the formation of channels inside the microparticles thus favoring the diffusion of flavonoids to ML. The mechanism of flavonoid release was only determined by channelizing agents, independently of the flavonoid nature, that is, Fickian and non-Fickian diffusion mechanisms in microparticles with and without Capsul, respectively.

Molecular Mechanisms of Androstenediol in the Regulation of the Proliferative Process of Human Endometrial Cells

Proliferation in endometria of women with polycystic ovarian syndrome (PCOS) is increased, similar to the biosynthesis of androstenediol (estrogenic metabolite). As previously shown, in human endometrial cells, androstenediol increases CYCLIN D1 levels and KI67 and decreases P27 content. The objective of the present investigation was to determine the mechanisms by which androstenediol promotes endometrial cell-cycle progression. Estrogen receptor α (ERα) activation and changes in CYCLIN D1 and P27 levels were evaluated by Western blot in T-HESC and St-T1b endometrial cell lines, using receptor antagonists; activation of PI3K-protein kinase B (AKT) and mitogen-activated protein kinases-extracellular signal–regulated kinases (MAPK-ERK)1/2 pathways was evaluated using PI3K, MAPK/ERK kinase (MEK)1/2, and RNA-polymerase II inhibitors. The data showed that androstenediol treatment significantly increases CYCLIN D1 and decreases P27 levels through ERα activation (P < .05). In addition, an increase in AKT/ERK1/2 phosphorylations was determined (P < .05). In the presence of RNA-polymerase II inhibitor, phosphorylation of AKT/ERK1/2 decreased (P < .05), meaning that endometrial cells need transcriptional activity to activate the kinases involved. It was also observed that PI3K action is required for P27 and CYCLIN D1 changes. Therefore, the action of androstenediol in endometria depends on PI3K-AKT and MAPK-ERK1/2 pathways activation, together with cell transcriptional machinery. This could be of clinical significance, as in pathologies such as PCOS, increased endometrial levels of androstenediol together with a high prevalence of endometrial hyperplasia and adenocarcinoma have been reported.

Release Kinetic in Yogurt from Gallic Acid Microparticles with Chemically Modified Inulin

Gallic acid (GA) was encapsulated with native (NIn), cross-linked (CIn) and acetylated (AIn) inulin by spray-drying. Inulin microparticles were characterized by encapsulation efficiency (EE) and their release profile in yogurt. The EE was significantly higher for GA-CIn (98%) compared with GA-NIn (81%) and GA-AIn (77%) microparticles, showing the effect of the modification of inulin on interaction of GA-polymer. GA release profile data in yogurt for GA-CIn, GA-NIn and GA-AIn were fitted to Peppas and Higuchi models in order to obtain the GA release rate constant. Although the GA release rate constants were significantly different among systems, these differences were slight and the GA release was fast (80% < 2 h) in the three systems, showing that inulin-systems did not control GA release in yogurt. The mechanism of GA release followed a Fickian diffusion and relaxation of chains for all microparticles. According to the release profile, these microparticles would be best suited for use in instant foods.

Effect of TNF-α on Molecules Related to the Insulin Action in Endometrial Cells Exposed to Hyperandrogenic and Hyperinsulinic Conditions Characteristics of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) affects not only ovarian functions but is also able to affect endometrium metabolism. Around 80% of women with PCOS are obese. High tumor necrosis factor (TNF)-α production and low adiponectin levels are characteristics of obesity. Interestingly, endometrium from obese women with PCOS presents an insulin-resistance condition, high TNF-α levels, and low adiponectin levels. However, TNF-α effect on molecules associated with insulin action in endometrial cells remains unclear. Therefore, the objective of this work was to evaluate TNF-α effect on expression of molecules associated with adiponectin (insulin sensitizing) and TNF-α signaling pathways and on Glucose Transporter type 4 (GLUT-4) levels in human endometrial cells under the characteristic conditions of hyperandrogenic/hyperinsulinic (HA/HI) PCOS. Two human endometrial stromal cell lines (T-HESC/St-T1b) under HA/HI conditions were used to assay the effect of high TNF-α concentration (100 ng/mL) on adiponectin, AdipoR1-AdipoR2 receptors, Adaptor protein phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1), Phospho-AMP-activated protein kinase T172 (p-AMPKT172), GLUT-4, Tumor necrosis factor receptor 1 (TNFR1)-Tumor necrosis factor receptor 2 (TNFR2) receptors protein levels, and nuclear factor κB (NFκB) nuclear content, by Western blot or immunocytochemistry. The NFκB participation in TNF-α effect on adiponectin expression was assayed using an NFκB inhibitor (pyrrolidine dithiocarbamate). The TNF-α increases the expression of molecules associated with its own signaling pathway (P < .05) and decreases the protein levels of adiponectin and its associated molecules (P < .05). Moreover, TNF-α increases NFκB nuclear content (P < .001), whereas with NFκB inhibition the decrease in adiponectin content induced by TNF-α was not observed. GLUT-4 levels were lower with TNF-α treatment (P < .01). Thus, in human endometrial stromal cells, high TNF-α levels negatively affect the insulin action through decreased adiponectin signaling and GLUT-4 protein. This could explain the failures observed in endometrial function of obese women with PCOS.

Abstract A45: Proteins involved in the Calreticulin translocation pathway are altered in human ovarian cancer samples.

Ovarian cancer is the seventh most common cancer among women worldwide, with more than 200,000 new cases every year. The 5-year survival rate of advanced ovarian cancer ranges from 11 to 28 per cent. Thus, a better understanding of its pathogenesis at a molecular level is necessary to develop more effective therapies. Calreticulin (CRT) is a Ca+2 binding chaperone localized mainly in the endoplasmic reticulum (ER). However, it has been found in other cellular compartments, including the cytosol, nucleus, the plasma membrane and the extracellular space. At the cell surface, CRT acts as an “eat-me” signal, allowing the recognition of a cancer cell by the immune system and inducing an anti-cancer immune response. CRT translocation from the ER to the plasma membrane can be induced by several cytotoxic anti-cancer drugs; however, the exact mechanism is not completely understood. It involves the activation of an ER stress response, particularly the activation of PERK and eIF2αproteins. Once on the cell membrane, CRT would be able to interact with CD91. In previous work, we found that CRT levels increase in ovarian cancer samples compared to non-cancerous tumors and normal tissue. By immunohistochemistry, we detected CRT on the periphery of normal inactive cells, while it had a mainly perinuclear distribution on cancer cells, consistent with ER localization. We have also found that Nerve Growth Factor (NGF) is involved in ovarian cancer pathogenesis and it increases CRT protein levels in a human ovarian cancer cell line (A2780). The aim of this work was to evaluate the levels of proteins associated with CRT translocation, including eIF2α, PERK and CD91 in human ovarian samples and to evaluate CRT subcellular localization in A2780 cells treated with NGF, thapsigargin (ER inductor) and mitoxantrone (cytotoxic drug) for 2 and 4 hours. Human ovarian samples (six normal inactive ovarian tissues, twelve ovarian tumors and sixteen epithelial ovarian cancer samples) were obtained after written consent by patients from the Clinical Hospital University of Chile and with approval of its Ethics Committee. In ovarian tissues, levels of eIF2α, PERK and CD91 were evaluated by western blot and the localization of CD91 was evaluated by immunohistochemistry. CRT localization in treated A2780 cells was determined by confocal immunofluorescence microscopy. We found increased levels of phosphorylated eIF2α and phosphorylated PERK (active forms) relative to total protein, in ovarian cancer samples compared to tumors (p Several studies have shown that the ER stress response is elevated in several types of cancer. In this work, we found that this is also the case in epithelial ovarian cancer. These results suggest that ovarian cancer tissues have the machinery necessary to induce CRT translocation, including the presence of CD91, making it an attractive target for future immunotherapy developments. However, despite the activation of at least part of the pathway, CRT seems to remain on the endoplasmic reticulum in cancer cells. This could be indicating the presence of a mechanism that inhibits its mobilization, possibly involving NGF. Grants: FONDECYT 1110372, CONICYT-FONDAP 15130011 and CONICYT Scholarship 21120252 Citation Format: Carolina Vera, Paula Garcia, Alberto Selman, Fernando Gabler, Margarita Vega, Arturo Ferreira, Carmen Romero. Proteins involved in the Calreticulin translocation pathway are altered in human ovarian cancer samples. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A45.