Native plants from Argentina reported as effective against Leishmania spp.

Leishmaniasis represents a spectrum of diseases caused by infection with protozoan pathogens of the genus Leishmania. It is a major neglected tropical disease associated with high rates of disability and death, with extended endemic areas in the Americas. Despite current therapeutic approaches, current treatments for leishmaniasis are unsatisfactory due to high associated toxicity, cost, complex administration and the emergence of resistant strains. Because of this, efforts have greatly increased over the last decade to identify novel compounds with anti-leishmanial properties. Thus, one strategy in the search for new compounds is the screening of molecules purified from plant sources. The current work reviewed the available information about the Argentinean natural sources reported as effective against Leishmania spp; including: its relevant chemical compounds, efficiency and applied methodology. Reported studies need to be considered as precursors works to extend the search between the profuse native plants from Argentina.Fil: Lozano, Esteban Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Fisiología; ArgentinaFil: Hapon, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo. ; ArgentinaFil: Cargnelutti, D. E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo. ; ArgentinaFil: Gamarra Luques, Carlos Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentin

Mifepristone increases mRNA translation rate, triggers the unfolded protein response, increases autophagic flux, and kills ovarian cancer cells in combination with proteasome or lysosome inhibitors

The synthetic steroid mifepristone blocks the growth of ovarian cancer cells, yet the mechanism driving such effect is not entirely understood. Unbiased genomic and proteomic screenings using ovarian cancer cell lines of different genetic backgrounds and sensitivities to platinum led to the identification of two key genes upregulated by mifepristone and involved in the unfolded protein response (UPR): the master chaperone of the endoplasmic reticulum (ER), glucose regulated protein (GRP) of 78 kDa, and the CCAAT/enhancer binding protein homologous transcription factor (CHOP). GRP78 and CHOP were upregulated by mifepristone in ovarian cancer cells regardless of p53 status and platinum sensitivity. Further studies revealed that the three UPR-associated pathways, PERK, IRE1α, and ATF6, were activated by mifepristone. Also, the synthetic steroid acutely increased mRNA translation rate, which, if prevented, abrogated the splicing of XBP1 mRNA, a non-translatable readout of IRE1α activation. Moreover, mifepristone increased LC3-II levels due to increased autophagic flux. When the autophagic–lysosomal pathway was inhibited with chloroquine, mifepristone was lethal to the cells. Lastly, doses of proteasome inhibitors that are inadequate to block the activity of the proteasomes, caused cell death when combined with mifepristone; this phenotype was accompanied by accumulation of poly-ubiquitinated proteins denoting proteasome inhibition. The stimulation by mifepristone of ER stress and autophagic flux offers a therapeutic opportunity for utilizing this compound to sensitize ovarian cancer cells to proteasome or lysosome inhibitors.Fil: Zhang, Lei. University Of South Dakota; Estados UnidosFil: Hapon, María Belén. University Of South Dakota; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Goyeneche, Alicia A.. University Of South Dakota; Estados Unidos. McGill University; CanadáFil: Srinivasan, Rekha. University Of South Dakota; Estados UnidosFil: Gamarra Luques, Carlos Diego. University Of South Dakota; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Callegari, Eduardo A.. University Of South Dakota; Estados UnidosFil: Drappeau, Donis D.. University Of South Dakota; Estados UnidosFil: Terpstra, Erin J.. University Of South Dakota; Estados UnidosFil: Pan, Bo. University Of South Dakota; Estados UnidosFil: Knapp, Jennifer R.. University of Kansas; Estados UnidosFil: Chien, Jeremy. University of Kansas; Estados UnidosFil: Wang, Xuejun. University Of South Dakota; Estados UnidosFil: Eyster, Kathleen M.. University Of South Dakota; Estados UnidosFil: Telleria, Carlos Marcelo. University Of South Dakota; Estados Unidos. McGill University; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Mifepristone prevents repopulation of ovarian cancer cells escaping cisplatin-paclitaxel therapy

<p>Abstract</p> <p>Background</p> <p>Advanced ovarian cancer is treated with cytoreductive surgery and combination platinum- and taxane-based chemotherapy. Although most patients have acute clinical response to this strategy, the disease ultimately recurs. In this work we questioned whether the synthetic steroid mifepristone, which as monotherapy inhibits the growth of ovarian cancer cells, is capable of preventing repopulation of ovarian cancer cells if given after a round of lethal cisplatin-paclitaxel combination treatment.</p> <p>Methods</p> <p>We established an <it>in vitro</it> approach wherein ovarian cancer cells with various sensitivities to cisplatin or paclitaxel were exposed to a round of lethal doses of cisplatin for 1 h plus paclitaxel for 3 h. Thereafter, cells were maintained in media with or without mifepristone, and short- and long-term cytotoxicity was assessed.</p> <p>Results</p> <p>Four days after treatment the lethality of cisplatin-paclitaxel was evidenced by reduced number of cells, increased hypodiploid DNA content, morphological features of apoptosis, DNA fragmentation, and cleavage of caspase-3, and of its downstream substrate PARP. Short-term presence of mifepristone either enhanced or did not modify such acute lethality. Seven days after receiving cisplatin-paclitaxel, cultures showed signs of relapse with escaping colonies that repopulated the plate in a time-dependent manner. Conversely, cultures exposed to cisplatin-paclitaxel followed by mifepristone not only did not display signs of repopulation following initial chemotherapy, but they also had their clonogenic capacity drastically reduced when compared to cells repopulating after cisplatin-paclitaxel.</p> <p>Conclusions</p> <p>Cytostatic concentrations of mifepristone after exposure to lethal doses of cisplatin and paclitaxel in combination blocks repopulation of remnant cells surviving and escaping the cytotoxic drugs.</p

Synergistic Lethality of Mifepristone and LY294002 in Ovarian Cancer Cells

We have previously shown that the antiprogestin and antiglucocorticoid mifepristone inhibits the growth of ovarian cancer cells. In this work, we hypothesized that cellular stress caused by mifepristone is limited to cytostasis and that cell killing is avoided as a consequence of the persistent activity of the PI3K/Akt survival pathway. To investigate the role of this pathway in mifepristone-induced growth inhibition, human ovarian cancer cells of various histological subtypes and genetic backgrounds were exposed to cytostatic doses of mifepristone in the presence or absence of the PI3K inhibitor, LY294002. The activation of Akt in ovarian cancer cells, as marked by its phosphorylation on Ser473, was not modified by cytostatic concentrations of mifepristone, but it was blocked upon treatment with LY294002. The combination mifepristone/LY294002, but not the individual drugs, killed ovarian cancer cells via apoptosis, as attested by genomic DNA fragmentation and cleavage of caspase-3, and the concomitant downregulation of antiapoptotic proteins Bcl-2 and XIAP. From a pharmacological standpoint, when assessing cell growth inhibition using a median-dose analysis algorithm, the interaction between mifepristone and LY294002 was synergistic. The lethality caused by the combination mifepristone/LY294004 in 2-dimensional cell cultures was recapitulated in organized, 3-dimensional spheroids. This study demonstrates that mifepristone and LY294002 when used individually cause cell growth arrest; yet, when combined, they cause lethality

Chemical characterization and biological activities of Tessaria absinthiodes (Hook. & Arn.) dc. (Asteraceae) decoction

The decoction of Tessaria absinthioides is used in traditional medicine of South America as a hypocholesterolemic, balsamic, and expectorant, it is also useful for the prevention of hepatitis, renal insufficiency, diabetes and used as digestive. A lyophilized decoction from the aerial parts of this plant collected in San Juan (TLDSJ) and Mendoza (TLDM) provinces (Argentine) and one collection from Antofagasta, Chile (TLDCH), were evaluated regarding antioxidant activities, phenolics and flavonoids content and UHPLC-MS metabolome fingerprinting which revealed the presence of several small bioactive compounds. The antioxidant properties were evaluated by free radical scavenging methods (DPPH and TEAC), ferric-reducing antioxidant power (FRAP) and lipoperoxidation in erythrocytes (LP). The antibacterial activity was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. TLDSJ, TLDSJ and TLDCH displayed a strong DPPH scavenging activity (IC50 = 42, 41.6 and 43 µg/mL respectively) and inhibition of lipoperoxidation in erythrocytes (86-88 % at 250 µgTLD/mL), while a less effect in the FRAP and ABTS antioxidant assays were found. Additionally, the decoctions showed a content of phenolics compounds of 94 mg GAE/g, 185 GAE/g and 64 GAE/g, for TLDSJ, TLDM TLDCH samples respectively. Regarding the flavonoid content, the Chilean sample was highlighted with 19 mg QE/g. In this work thirty phenolics compounds including sesquiterpenes, flavonoids, and phenolics acids were rapidly identified in TLDSJ, TLDM and TLDCH decoctions by means of ultrahigh resolution liquidchromatography orbitrap MS analysis (UHPLC-PDAOT-MS) for the first time, which support that the medicinal decoction from both countries is a valuable natural product with antioxidant effects and with potential to improve human health. Additionally, this research opens a pathway for the development of important phytomedicine products.Fil: Gómez, J.. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Simirgiotis, M. J.. Universidad Austral de Chile; ChileFil: Lima, Beatriz Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Gamarra Luques, Carlos Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Bórquez, J.. Universidad de Antofagasta. Facultad de Ciencias Básicas. Laboratorio de Productos Naturales; ChileFil: Caballero, D.. Hospital Público Descentralizado Dr. Marcial Quiroga.; ArgentinaFil: Tapia, A.. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaXXXVII Reunión Científica Anual de la Sociedad de Biología de CuyoSan LuisArgentinaSociedad de Biología de Cuy

Antioxidant, Gastroprotective, Cytotoxic Activities and UHPLC PDA-Q Orbitrap Mass Spectrometry Identification of Metabolites in Baccharis grisebachii Decoction

The decoction of the local plant Baccharis grisebachii is used as a digestive, gastroprotective, external cicatrizing agent and antiseptic in Argentine. A lyophilized decoction (BLD) from the aerial parts of this plant was evaluated regarding its anti-ulcer, antioxidant and cytotoxic activities and the bioactivities were supported by UHPLC-MS metabolome fingerprinting which revealed the presence of several small bioactive compounds. The antioxidant properties were evaluated by DPPH, TEAC, FRAP and lipoperoxidation inhibition in erythrocytes methods, and the antibacterial activity was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. The BLD showed a moderate free radical scavenging activity in the DPPH (EC50 = 106 &micro;g/mL) and lipid peroxidation in erythrocytes assays (67%, at 250 &micro;g/mL). However, the BLD had the highest gastroprotective effect at a dose of 750 mg/kg with a ninety-three percent inhibition of damage through a mechanism that involve NO and prostaglandins using the ethanol-induced gastric damage in a standard rat model. On the other hand, BLD does not induce cytotoxic changes on human tumor and no-tumor cell lines at the concentrations assayed. Regarding the metabolomic analysis, thirty-one compounds were detected and 30 identified based on UHPLC-OT-MS including twelve flavonoids, eleven cinnamic acid derivatives, one coumarin, one stilbene and two other different phenolic compounds. The results support that the medicinal decoction of Baccharis grisebachii is a valuable natural product with gastroprotective effects and with potential to improve human health that opens a pathway for the development of important phytomedicine products

Mifepristone increases mRNA translation rate, triggers the unfolded protein response, increases autophagic flux, and kills ovarian cancer cells in combination with proteasome or lysosome inhibitors

The synthetic steroid mifepristone blocks the growth of ovarian cancer cells, yet the mechanism driving such effect is not entirely understood. Unbiased genomic and proteomic screenings using ovarian cancer cell lines of different genetic backgrounds and sensitivities to platinum led to the identification of two key genes upregulated by mifepristone and involved in the unfolded protein response (UPR): the master chaperone of the endoplasmic reticulum (ER), glucose regulated protein (GRP) of 78&nbsp;kDa, and the CCAAT/enhancer binding protein homologous transcription factor (CHOP). GRP78 and CHOP were upregulated by mifepristone in ovarian cancer cells regardless of p53 status and platinum sensitivity. Further studies revealed that the three UPR-associated pathways, PERK, IRE1α, and ATF6, were activated by mifepristone. Also, the synthetic steroid acutely increased mRNA translation rate, which, if prevented, abrogated the splicing of XBP1 mRNA, a non-translatable readout of IRE1α activation. Moreover, mifepristone increased LC3-II levels due to increased autophagic flux. When the autophagic-lysosomal pathway was inhibited with chloroquine, mifepristone was lethal to the cells. Lastly, doses of proteasome inhibitors that are inadequate to block the activity of the proteasomes, caused cell death when combined with mifepristone; this phenotype was accompanied by accumulation of poly-ubiquitinated proteins denoting proteasome inhibition. The stimulation by mifepristone of ER stress and autophagic flux offers a therapeutic opportunity for utilizing this compound to sensitize ovarian cancer cells to proteasome or lysosome inhibitors