Hepatocellular carcinoma (HCC) is one of the most frequent tumors worldwide, associated with a hi... more Hepatocellular carcinoma (HCC) is one of the most frequent tumors worldwide, associated with a high mortality rate. HCC patient's prognosis remains unfavorable, mainly due to late diagnosis and treatment instauration delay. Thus, there is an urgent requirement for the development of new therapeutical options, particularly for advanced HCC patients. Polyphenols are specialized plant metabolites, which have been broadly characterized for their beneficial effects on human health. Potato is one of the main sources of these compounds in human diet, due to its high consumption. The objectives of this study were to: characterize the polyphenolic composition, analyze the antioxidant properties, evaluate the cytotoxic activity in human tumoral hepatocytes, and describe the molecular mechanisms involved in cell death, of potato polyphenolic extracts (PPEs) from the pigmented Andigena cultivar CL658. The results showed that phenolic acids were the main group of polyphenols in the extracts, chlorogenic acid being the major compound, followed by caffeic acid. HPLC‐DAD profile showed pelargonidin as the principal anthocyanin. The treatment of HCC cell lines with the cytotoxic concentration 50 (CC50) of the PPEs resulted in cytotoxicity, evidenced by increases in the percentage of dead cells (5–10%) after treatments. This cytotoxic effect was mainly due to apoptosis activation, evidenced by modulation of the Bcl‐2 family proteins expression, in favor of pro‐apoptotic members over anti‐apoptotic in the final balance. PPEs also induced autophagy, indicated by increased LC3 expression (122–274%) and autophagosomes, and reduced p62 expression (32–48%), in variable magnitudes according to the treated cell line. Overall, these results support the potential use of PPEs from the cultivar CL658 as a source of bioactive compounds for novel treatments against HCC.
bioRxiv (Cold Spring Harbor Laboratory), Feb 3, 2023
Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such ... more Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such as phenolic acid and flavonoids. These polyphenols have several beneficial effects on human health due to their antioxidant properties. Previously, we demonstrated that polyphenol extracts from Andean potato tubers exerted a concentrationdependent cytotoxic effect in human neuroblastoma cells. However, the mechanisms involved in this cytotoxic activity were not explored. Here we show that Santa María tuber's polyphenols activated a programmed cell death by caspase-independent apoptosis. We found that polyphenols induced cell and nucleus morphology changes and slightly affected the cell cycle. Furthermore, the polyphenols altered the neuroblastoma cells' homeostasis redox and mitochondrial function, increasing the levels of apoptotic cells. Finally, we showed that neither Bcl-2 nor caspase-3 was involved in this mechanism of death. Our results confirmed that Santa María tuber's polyphenols are bioactive compounds with mitochondria as a target and contribute to revalorizing Andean potatoes as a functional food. These findings demonstrated that they would be a good source of anti-tumor compounds that would induce tumor cell death even in apoptotic-resistant tumors, opening new therapeutic avenues.
bioRxiv (Cold Spring Harbor Laboratory), Oct 14, 2022
Andean potatoes (Solanum tuberosum L. ssp. andigena) are a good source of dietary antioxidant pol... more Andean potatoes (Solanum tuberosum L. ssp. andigena) are a good source of dietary antioxidant polyphenols. We have previously demonstrated that polyphenol extracts from Andean potato tubers exerted a dose-dependent cytotoxic effect in human neuroblastoma SH-SY5Y cells, being skin extracts more potent than flesh ones. In order to gain insight into the bioactivities of potato phenolics, we investigated the composition and the in vitro cytotoxic activity of total extracts and fractions of skin and flesh tubers of three Andean potato cultivars (Santa María, Waicha, and Moradita). Potato total extracts were subjected to liquid-liquid fractionation using ethyl acetate solvent in organic and aqueous fractions. We analyzed both fractions by HPLC-DAD, HPLC-ESI-MS/MS, and HPLC-HRMS. Results corroborated the expected composition of each fraction. Organic fractions were rich in hydroxycinnamic acids (principally chlorogenic acid isomers), whereas aqueous fractions contained mainly polyamines conjugated with phenolic acids, glycoalkaloids, and flavonoids. Organic fractions were not cytotoxic against SH-SY5Y cells, and indeed, some increased cellular metabolism compared to controls. Aqueous fractions were cytotoxic and even more potent than their respective total extracts. Treatment with a combination of both fractions showed a similar cytotoxic response to the corresponding extract. According to correlation studies, it is tempting to speculate that polyamines and glycoalkaloids are crucial in inducing cell death. Our findings indicate that the activity of Andean potato extracts is a combination .
Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such ... more Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such as phenolic acid and flavonoids. These polyphenols have several beneficial effects on human health due to their antioxidant properties. Previously, we demonstrated that polyphenol extracts from Andean potato tubers exerted a concentrationdependent cytotoxic effect in human neuroblastoma cells. However, the mechanisms involved in this cytotoxic activity were not explored. Here we show that Santa María tuber's polyphenols activated a programmed cell death by caspase-independent apoptosis. We found that polyphenols induced cell and nucleus morphology changes and slightly affected the cell cycle. Furthermore, the polyphenols altered the neuroblastoma cells' homeostasis redox and mitochondrial function, increasing the levels of apoptotic cells. Finally, we showed that neither Bcl-2 nor caspase-3 was involved in this mechanism of death. Our results confirmed that Santa María tuber's polyphenols are bioactive compounds with mitochondria as a target and contribute to revalorizing Andean potatoes as a functional food. These findings demonstrated that they would be a good source of anti-tumor compounds that would induce tumor cell death even in apoptotic-resistant tumors, opening new therapeutic avenues.
bioRxiv (Cold Spring Harbor Laboratory), Jul 7, 2021
Background: The 4CL/ ACS protein family is well known for its 4-coumarate-CoA ligase (4CL) enzyme... more Background: The 4CL/ ACS protein family is well known for its 4-coumarate-CoA ligase (4CL) enzymes but there are many aspects of this family that are still unclear or generally known. Cytosolic class I and class II 4CL enzymes control the biosynthesis of lignin/ suberin and flavonoids, respectively. Many 4CL homologs have broad substrate permissiveness in vitro and have no clear cut function. However, it has been demonstrated unequivocally that a peroxisomal 4CL-like homolog from Arabidopsis efficiently uses p-coumarate for ubiquinone biosynthesis. Another homolog has been shown to act as a fatty acyl-CoA synthetase and yet another as OPDA-CoA ligase. Hence, despite this knowledge, most homologs remain annotated as "4CL-like" whereas other researches study the ACS protein family. Results: We set out identify the specific functions of 4CL/ ACS homologs, specifically in order to study the 4CL family in Solanum tuberosum. An in depth phylogenetic analysis was done. Using clustering techniques, functional annotation and taxonomic signals, three major clades were depicted. Clade 1 is composed of class I from monocotyledons, class I from dicotyledons and class II canonical 4CL enzymes subclades. Specificity determining positions and 3D structure analysis shows that clade 2 cytosolic 4CL-like enzymes show a rather different binding cleft and presumably use medium-to long-chain fatty acids. Clade 3 is composed of five subclades, four of which have a broad taxonomic contribution and a similar binding cleft as 4CLs whereas a fifth, specific for dicotyledons shows a significantly different binding pocket. The potato 4CL family comprises four class I (St4CL-I(A-D)) and one class II (St4CL-II) members. Transcript levels of St4CLs and of marker genes of the flavonoid (chalcone synthase, CHS) and suberin (feruloyl-CoA transferase, FHT) pathways were determined by qRT-PCR in flesh and skin from Andean varieties. St4CL-IA was barely detected in the skin of some varieties whereas St4CL-IB did not show a clear pattern. St4CL-IC and St4CL-ID could not be detected. St4CL-II expression pattern was similar to CHS. St4CL-IA and St4CL-IB were induced by wounding as did FHT whereas St4CL-II and CHS expression was repressed. Constitutive and wound-induced expression suggests that St4CL-IA and St4CL-IB isoforms are likely involved in soluble and/ or suberin-bound phenolic compounds while St4CL-II appears to be involved in flavonoid biosynthesis.
The phosphites (Phi) are inducers of plant defense responses, although also other effects were re... more The phosphites (Phi) are inducers of plant defense responses, although also other effects were reported. In kiwifruit (Actinidia deliciosa Hayward), we demonstrated that Phi-treated fruit was more tolerant to gray mold development caused by Botrytis cinerea. The mechanisms are not yet well elucidated. The objective of this work was to evaluate the effect of Phi (30% P2O5, 20% K2O), 0.3% (v/v) on Hayward fruit maturity and quality indexes, by application at different physiological stages of the fruit development: T1) one application at bloom; T2) six weekly Phi applications at the exponential phase of fruit growth; T3) combination of treatments, 1 and 2; T4) control (without Phi). Kiwifruits of all treatments were harvested after physiological maturity (at least 6.2% total soluble solids content, SSC) and were analyzed at harvest in terms of firmness (N), SSC (%), titratable acidity (%) and color (CIELab). Also fruits were evaluated after 4 months of cold storage and shelf-life (7 days at 20°C). Ethylene and carbon dioxide rate production were determined at 20°C in the fruits of all treatments. The experiment was conducted during two consecutive years. The results show that the Phi had an effect on firmness, variation between years, while had no effects on other maturity indexes. Firmness of Phi-treated fruits was higher than control ones at shelf-life, essentially when Phi was applied at the exponential phase of fruit growth. This change in the softening rate was associated with the ethylene production rate that was too affected by some Phi treatments. Phi treatments (T2 and T3) significantly affected the ethylene and respiration rates, reducing significantly the values at the climacteric peak. This result suggests that Phi affects perception or biosynthesis of ethylene, and some of this response may be related to the induction of salicylic acid.Fil: Yommi, Alejandra Karina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Baeza, Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Quillehauquy, V.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Fasciglione, Gabriela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Casanovas, Elda Mabel. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Borrajo, María Paula. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina; ArgentinaFil: Gomez Di Marco, P. A.. Universidad Politécnica de Cartagena, Murcia, Spain; EspañaFil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin
La enfermedad conocida como "Sarna Común de la Papa" (SCP), causada por Actinomycetes d... more La enfermedad conocida como "Sarna Común de la Papa" (SCP), causada por Actinomycetes del genero Streptomyces spp. provoca al cultivo importantes perdidas de rendimiento y calidad comercial de los tubérculos cosechados...Fil: Conde, Manuel Eloy. Diagnósticos Vegetales SA; ArgentinaFil: Suarez, Patricia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Escarrá, Ana María. Diagnósticos Vegetales SA; Argentin
Nuevas tecnologías de cosecha y poscosecha, y su impacto en la calidad de frutas frescas, 2020
Existen distintas herramientas tecnológicas que se aplican a fin de retrasar los cambios que acom... more Existen distintas herramientas tecnológicas que se aplican a fin de retrasar los cambios que acompañan al proceso de maduración y prolongar la vida poscosecha del kiwi. Una de ellas es la refrigeración porque a bajas temperaturas se reducen tanto la síntesis de etileno como el ablandamiento. Otra de las herramientas es el uso de inhibidores de la maduración, como es el caso del 1-metilciclopropeno (1-MCP). Cuando se aplica luego de la cosecha, se deprime la tasa de respiración, la producción de etileno, el ablandamiento, el desarrollo de color y las pudriciones de los frutos (Kim et al., 2001; Park et al., 2015). El efecto se revierte en la medida que se sintetizan nuevos receptores de membrana para el etileno (Blankenship; Dole, 2003). Por una parte, la respuesta al 1-MCP es afectada por varios factores, tales como el estado de madurez a cosecha (Valero et al., 2003), la dosis aplicada (Salvador et al., 2000; Cantin et al., 2011), la duración de la exposición de la fruta al 1-MCP (Abdi et al., 1998, Cantin et al., 2011), la temperatura de la fruta al momento de la aplicación del 1-MCP (Abdi et al., 1998; Cantin et al., 2011) y el momento de la aplicación con distintas dosis (Boquete et al., 2004; Menniti et al., 2005). Por otra parte, la modificación de la composición gaseosa del ambiente en el que se encuentra almacenado el fruto es otra herramienta que permite retrasar los cambios asociados a la maduración. La atmósfera controlada (AC) consiste en realizar un exhaustivo control de las concentraciones de O2 y CO2 del entorno gaseoso del producto mediante el empleo de equipamiento adecuado. En kiwi se recomienda modificar los niveles de gases existentes en el aire (78,0 % de N2 , 20,9 % de O2 , y 0,03 % de CO2 ) a valores de 2 % de O2 y 5 % de CO2 , removiendo el etileno para mantener una concentración por debajo de 0,001 µl L-1 (Arpaia et al., 1986). Estos cambios en la composición gaseosa tienen efectos muy importantes sobre el mantenimiento de la firmeza de los frutos (Botondi et al., 2012). En este sentido, Zoffoli et al. (2002) demostraron que la modificación de la atmósfera redujo la tasa de ablandamiento en frutos de kiwi de 0,073 lb/día a 0,006 lb/día a los 52 días de almacenaje a 0 °C. Es escasa la información internacional sobre el uso combinado de AC y 1-MCP. Con la hipótesis de que la AC retrasa la maduración y que su uso combinado con 1-MCP tiene un efecto sinérgico sobre el ablandamiento y un efecto residual cuando la fruta es transferida a temperatura ambiente durante su comercialización, el objetivo de este trabajo fue evaluar el uso de la atmósfera controlada, combinada o no con la aplicación de 1-MCP, y su efecto sobre distintos índices de calidad en frutos de kiwi Haywardproducidos en el sudeste de la provincia de Buenos Aires. Los resultados muestran que el almacenamiento en AC y la aplicación de 1-MCP permiten retener la firmeza de la pulpa del kiwi y prolongar su guarda, aunque su combinación no sería recomendable por producir una desincronización del proceso normal de ablandamiento de la pulpa y la columela. El contenido de AA se mantuvo estable durante el almacenamiento hasta los 7 meses de guarda, ya a partir del mes 8 comenzó a disminuir, aunque no en una magnitud considerable.Fil: Quillehauquy, Victoria. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Baeza, María Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Yommi, A.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Moreno, A.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Fasciglione, Gabriela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin
Phosphites (Phi) have the ability to protect plants against different pathogens, both through a d... more Phosphites (Phi) have the ability to protect plants against different pathogens, both through a direct effect in oomycete metabolism and by an indirect effect stimulating the plant ́s natural defence responses. We have previously shown that KPhi foliar application to potato plants resulted in different protection levels against Phytophthora infestans depending on dose and plant age at application time. In order to identify genes that are involved in induced resistant in plants treated with KPhi, we analyzed by RT PCR, the time course of transcript levels of two genes which encode predicted transcription factors involved in pathogen perception and defence gene expression. Preliminary results showed that WRKY and NPR1 were differentially induced in plants both treated with Phi and infected with Phytophthora infestans, showing an earlier and highest induction than infected plants non treated with Phi. These results may allow us to hypothetize that Phi treatment might trigger a fast mec...
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
The potato periderm is the outer tissue of potato tubers that protects the tuber from pathogen at... more The potato periderm is the outer tissue of potato tubers that protects the tuber from pathogen attack, dehydration, and wounding during harvest and storage. It is of secondary origin and replaces the epidermis early during tuber development. The outer layers of the periderm consist of cells with suberized walls. Phosphite compounds (Phi) are inorganic salts from phosphorous acid, and in previous works, we demonstrated that they are effective in protecting potato plants from biotic stress caused by different pathogens and also against UV-B radiation. The aim of the present work was to study the effect of Phi on the post-harvest potato periderm structure, cell wall components, and related enzymes. In three years of field experiments, potassium phosphite (KPhi) applications were compared with an untreated control. KPhi was applied to seed tubers before planting combined with foliage application of a conventional fungicide, to seed tubers and foliage without conventional fungicide, or to seed tubers combined with foliage application of KPhi plus a conventional fungicide. Observations of periderm sections showed increases in suberin and pectin depositions in post-harvest tubers from KPhi-treated plants compared to tubers from non-treated plants. In addition, peroxidase activity increased in the periderm tissue. The activity of laccases and superoxide dismutase was measured in the protein extract of the periderm, and an increase due to KPhi treatment was detected. The results presented here suggest that early KPhi treatment to seed tubers followed by foliage treatment leads to reinforcement of the cell wall of periderm cells, which represents a benefit for future response to stresses.
Chitosan is obtained at industrial scale through a process of alkaline deacetylation of chitin th... more Chitosan is obtained at industrial scale through a process of alkaline deacetylation of chitin the major waste of shrimp industry. Its utilization could both diminish industrial environmental impact and add value to foods and other industrial products. In this study, an industrial chitosan obtained in Argentina and a commercial chitosan were physicochemically characterized and evaluated as edible coating for biopreservation of minimally processed lettuce. Based on Nuclear Magnetic Resonance, X-ray diffraction and thermogravimetric and viscosimetric assays we conclude that both biopolymers have similar molecular weight and deacetylation degree. The chitosan coatings were applied by spraying to lettuce leaves that had been removed and cleaned after the harvest. Each sample composed by four whole leaves, packed into a low-density polyethylene bag, was stored at 4°C for 15 d. Microbial quality, weight and color losses, antioxidant contents, stomatal closure and sensorial attributes were evaluated during storage. An initial reduction of 2 log in molds and yeast counts were obtained for both types of chitosan coatings. As a result, the counts remained below the limit value of 6 log for 12 d in the chitosan coatings, while in the control samples this limit was reached 6 d after storage. Total mesophilic bacteria counts were also reduced by both types of chitosan coatings, keeping counts under the threshold value of 7 log for 12 d while in control samples this value was exceeded at 9 d. Both chitosans increased chlorophyll content, total phenolic compounds and antioxidant activity in lettuce leaves during the storage. Besides, the leaf weight loss was minimized by both chitosan coatings, in accordance to a higher proportion of stomatal partial closure as seen by SEM. The overall visual quality was not affected by chitosan coatings. In conclusion, the industrial chitosan showed similar effects on stored minimally processed lettuce than the commercial chitosan adding value to a material that is currently considered a waste.
SDRP Journal of Food Science & Technology, 2017
Background: Polyphenols ar e plant metabolites that have been largely studied for their beneficia... more Background: Polyphenols ar e plant metabolites that have been largely studied for their beneficial effect on human health. Potato is one of the most important crops worldwide and is a relevant source of human dietary nutrients and antioxidants. Particularly, pigmented potatoes contain the highest levels of polyphenolic compounds. Hepatocellular carcinoma is one of the most frequent types of cancers worldwide and despite the existence of treatments; it is yet associated with a high mortality rate. Thus, new drugs are needed, and polyphenols are a potential source of antihepatocellular carcinoma compounds. The objectives of this study were to determine the content of different groups of polyphenols (phenolic acids, anthocyanins and flavan-3-ols) in five potato polyphenolic extracts, and to study their antioxidant and cytotoxic activities on a human hepatocellular carcinoma cell line. Methods: four Andean var ieties and one industr ial potato variety were selected for this study. Polyphenolic quantification and composition were determined by spectrophotometric assays and HPLC-DAD analysis. The antioxidant and cytotoxic activities were evaluated through DPPH and MTS assays respectively. Results showed that pigmented var ieties possessed higher levels of the analyzed phenolic compounds. HPLC analysis showed that chlorogenic acid was the main phenolic acid in all the potato polyphenolic extracts. Also, pigmented potatoes presented higher levels of antioxidant activity compared to non-pigmented ones, showing a positive correlation with the total phenolic content. Finally, treatment with three of the studied potato polyphenolic extracts reduced the viability of Hep3B. Furthermore, one extract from a nonpigmented variety affected cell viability to a similar extent as extracts from pigmented potatoes, suggesting that other compounds, besides anthocyanins, may be responsible of the cytotoxic effect of this polyphenolic extracts. Conclusion: These r esults suggested that polyphenolic compounds present in the Andean potato varieties could be used as a potential source of anti
Hepatocellular carcinoma (HCC) is one of the most frequent tumors worldwide, associated with a hi... more Hepatocellular carcinoma (HCC) is one of the most frequent tumors worldwide, associated with a high mortality rate. HCC patient's prognosis remains unfavorable, mainly due to late diagnosis and treatment instauration delay. Thus, there is an urgent requirement for the development of new therapeutical options, particularly for advanced HCC patients. Polyphenols are specialized plant metabolites, which have been broadly characterized for their beneficial effects on human health. Potato is one of the main sources of these compounds in human diet, due to its high consumption. The objectives of this study were to: characterize the polyphenolic composition, analyze the antioxidant properties, evaluate the cytotoxic activity in human tumoral hepatocytes, and describe the molecular mechanisms involved in cell death, of potato polyphenolic extracts (PPEs) from the pigmented Andigena cultivar CL658. The results showed that phenolic acids were the main group of polyphenols in the extracts, chlorogenic acid being the major compound, followed by caffeic acid. HPLC‐DAD profile showed pelargonidin as the principal anthocyanin. The treatment of HCC cell lines with the cytotoxic concentration 50 (CC50) of the PPEs resulted in cytotoxicity, evidenced by increases in the percentage of dead cells (5–10%) after treatments. This cytotoxic effect was mainly due to apoptosis activation, evidenced by modulation of the Bcl‐2 family proteins expression, in favor of pro‐apoptotic members over anti‐apoptotic in the final balance. PPEs also induced autophagy, indicated by increased LC3 expression (122–274%) and autophagosomes, and reduced p62 expression (32–48%), in variable magnitudes according to the treated cell line. Overall, these results support the potential use of PPEs from the cultivar CL658 as a source of bioactive compounds for novel treatments against HCC.
bioRxiv (Cold Spring Harbor Laboratory), Feb 3, 2023
Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such ... more Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such as phenolic acid and flavonoids. These polyphenols have several beneficial effects on human health due to their antioxidant properties. Previously, we demonstrated that polyphenol extracts from Andean potato tubers exerted a concentrationdependent cytotoxic effect in human neuroblastoma cells. However, the mechanisms involved in this cytotoxic activity were not explored. Here we show that Santa María tuber's polyphenols activated a programmed cell death by caspase-independent apoptosis. We found that polyphenols induced cell and nucleus morphology changes and slightly affected the cell cycle. Furthermore, the polyphenols altered the neuroblastoma cells' homeostasis redox and mitochondrial function, increasing the levels of apoptotic cells. Finally, we showed that neither Bcl-2 nor caspase-3 was involved in this mechanism of death. Our results confirmed that Santa María tuber's polyphenols are bioactive compounds with mitochondria as a target and contribute to revalorizing Andean potatoes as a functional food. These findings demonstrated that they would be a good source of anti-tumor compounds that would induce tumor cell death even in apoptotic-resistant tumors, opening new therapeutic avenues.
bioRxiv (Cold Spring Harbor Laboratory), Oct 14, 2022
Andean potatoes (Solanum tuberosum L. ssp. andigena) are a good source of dietary antioxidant pol... more Andean potatoes (Solanum tuberosum L. ssp. andigena) are a good source of dietary antioxidant polyphenols. We have previously demonstrated that polyphenol extracts from Andean potato tubers exerted a dose-dependent cytotoxic effect in human neuroblastoma SH-SY5Y cells, being skin extracts more potent than flesh ones. In order to gain insight into the bioactivities of potato phenolics, we investigated the composition and the in vitro cytotoxic activity of total extracts and fractions of skin and flesh tubers of three Andean potato cultivars (Santa María, Waicha, and Moradita). Potato total extracts were subjected to liquid-liquid fractionation using ethyl acetate solvent in organic and aqueous fractions. We analyzed both fractions by HPLC-DAD, HPLC-ESI-MS/MS, and HPLC-HRMS. Results corroborated the expected composition of each fraction. Organic fractions were rich in hydroxycinnamic acids (principally chlorogenic acid isomers), whereas aqueous fractions contained mainly polyamines conjugated with phenolic acids, glycoalkaloids, and flavonoids. Organic fractions were not cytotoxic against SH-SY5Y cells, and indeed, some increased cellular metabolism compared to controls. Aqueous fractions were cytotoxic and even more potent than their respective total extracts. Treatment with a combination of both fractions showed a similar cytotoxic response to the corresponding extract. According to correlation studies, it is tempting to speculate that polyamines and glycoalkaloids are crucial in inducing cell death. Our findings indicate that the activity of Andean potato extracts is a combination .
Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such ... more Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such as phenolic acid and flavonoids. These polyphenols have several beneficial effects on human health due to their antioxidant properties. Previously, we demonstrated that polyphenol extracts from Andean potato tubers exerted a concentrationdependent cytotoxic effect in human neuroblastoma cells. However, the mechanisms involved in this cytotoxic activity were not explored. Here we show that Santa María tuber's polyphenols activated a programmed cell death by caspase-independent apoptosis. We found that polyphenols induced cell and nucleus morphology changes and slightly affected the cell cycle. Furthermore, the polyphenols altered the neuroblastoma cells' homeostasis redox and mitochondrial function, increasing the levels of apoptotic cells. Finally, we showed that neither Bcl-2 nor caspase-3 was involved in this mechanism of death. Our results confirmed that Santa María tuber's polyphenols are bioactive compounds with mitochondria as a target and contribute to revalorizing Andean potatoes as a functional food. These findings demonstrated that they would be a good source of anti-tumor compounds that would induce tumor cell death even in apoptotic-resistant tumors, opening new therapeutic avenues.
bioRxiv (Cold Spring Harbor Laboratory), Jul 7, 2021
Background: The 4CL/ ACS protein family is well known for its 4-coumarate-CoA ligase (4CL) enzyme... more Background: The 4CL/ ACS protein family is well known for its 4-coumarate-CoA ligase (4CL) enzymes but there are many aspects of this family that are still unclear or generally known. Cytosolic class I and class II 4CL enzymes control the biosynthesis of lignin/ suberin and flavonoids, respectively. Many 4CL homologs have broad substrate permissiveness in vitro and have no clear cut function. However, it has been demonstrated unequivocally that a peroxisomal 4CL-like homolog from Arabidopsis efficiently uses p-coumarate for ubiquinone biosynthesis. Another homolog has been shown to act as a fatty acyl-CoA synthetase and yet another as OPDA-CoA ligase. Hence, despite this knowledge, most homologs remain annotated as "4CL-like" whereas other researches study the ACS protein family. Results: We set out identify the specific functions of 4CL/ ACS homologs, specifically in order to study the 4CL family in Solanum tuberosum. An in depth phylogenetic analysis was done. Using clustering techniques, functional annotation and taxonomic signals, three major clades were depicted. Clade 1 is composed of class I from monocotyledons, class I from dicotyledons and class II canonical 4CL enzymes subclades. Specificity determining positions and 3D structure analysis shows that clade 2 cytosolic 4CL-like enzymes show a rather different binding cleft and presumably use medium-to long-chain fatty acids. Clade 3 is composed of five subclades, four of which have a broad taxonomic contribution and a similar binding cleft as 4CLs whereas a fifth, specific for dicotyledons shows a significantly different binding pocket. The potato 4CL family comprises four class I (St4CL-I(A-D)) and one class II (St4CL-II) members. Transcript levels of St4CLs and of marker genes of the flavonoid (chalcone synthase, CHS) and suberin (feruloyl-CoA transferase, FHT) pathways were determined by qRT-PCR in flesh and skin from Andean varieties. St4CL-IA was barely detected in the skin of some varieties whereas St4CL-IB did not show a clear pattern. St4CL-IC and St4CL-ID could not be detected. St4CL-II expression pattern was similar to CHS. St4CL-IA and St4CL-IB were induced by wounding as did FHT whereas St4CL-II and CHS expression was repressed. Constitutive and wound-induced expression suggests that St4CL-IA and St4CL-IB isoforms are likely involved in soluble and/ or suberin-bound phenolic compounds while St4CL-II appears to be involved in flavonoid biosynthesis.
The phosphites (Phi) are inducers of plant defense responses, although also other effects were re... more The phosphites (Phi) are inducers of plant defense responses, although also other effects were reported. In kiwifruit (Actinidia deliciosa Hayward), we demonstrated that Phi-treated fruit was more tolerant to gray mold development caused by Botrytis cinerea. The mechanisms are not yet well elucidated. The objective of this work was to evaluate the effect of Phi (30% P2O5, 20% K2O), 0.3% (v/v) on Hayward fruit maturity and quality indexes, by application at different physiological stages of the fruit development: T1) one application at bloom; T2) six weekly Phi applications at the exponential phase of fruit growth; T3) combination of treatments, 1 and 2; T4) control (without Phi). Kiwifruits of all treatments were harvested after physiological maturity (at least 6.2% total soluble solids content, SSC) and were analyzed at harvest in terms of firmness (N), SSC (%), titratable acidity (%) and color (CIELab). Also fruits were evaluated after 4 months of cold storage and shelf-life (7 days at 20°C). Ethylene and carbon dioxide rate production were determined at 20°C in the fruits of all treatments. The experiment was conducted during two consecutive years. The results show that the Phi had an effect on firmness, variation between years, while had no effects on other maturity indexes. Firmness of Phi-treated fruits was higher than control ones at shelf-life, essentially when Phi was applied at the exponential phase of fruit growth. This change in the softening rate was associated with the ethylene production rate that was too affected by some Phi treatments. Phi treatments (T2 and T3) significantly affected the ethylene and respiration rates, reducing significantly the values at the climacteric peak. This result suggests that Phi affects perception or biosynthesis of ethylene, and some of this response may be related to the induction of salicylic acid.Fil: Yommi, Alejandra Karina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Baeza, Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Quillehauquy, V.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Fasciglione, Gabriela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Casanovas, Elda Mabel. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Borrajo, María Paula. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina; ArgentinaFil: Gomez Di Marco, P. A.. Universidad Politécnica de Cartagena, Murcia, Spain; EspañaFil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin
La enfermedad conocida como "Sarna Común de la Papa" (SCP), causada por Actinomycetes d... more La enfermedad conocida como "Sarna Común de la Papa" (SCP), causada por Actinomycetes del genero Streptomyces spp. provoca al cultivo importantes perdidas de rendimiento y calidad comercial de los tubérculos cosechados...Fil: Conde, Manuel Eloy. Diagnósticos Vegetales SA; ArgentinaFil: Suarez, Patricia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Escarrá, Ana María. Diagnósticos Vegetales SA; Argentin
Nuevas tecnologías de cosecha y poscosecha, y su impacto en la calidad de frutas frescas, 2020
Existen distintas herramientas tecnológicas que se aplican a fin de retrasar los cambios que acom... more Existen distintas herramientas tecnológicas que se aplican a fin de retrasar los cambios que acompañan al proceso de maduración y prolongar la vida poscosecha del kiwi. Una de ellas es la refrigeración porque a bajas temperaturas se reducen tanto la síntesis de etileno como el ablandamiento. Otra de las herramientas es el uso de inhibidores de la maduración, como es el caso del 1-metilciclopropeno (1-MCP). Cuando se aplica luego de la cosecha, se deprime la tasa de respiración, la producción de etileno, el ablandamiento, el desarrollo de color y las pudriciones de los frutos (Kim et al., 2001; Park et al., 2015). El efecto se revierte en la medida que se sintetizan nuevos receptores de membrana para el etileno (Blankenship; Dole, 2003). Por una parte, la respuesta al 1-MCP es afectada por varios factores, tales como el estado de madurez a cosecha (Valero et al., 2003), la dosis aplicada (Salvador et al., 2000; Cantin et al., 2011), la duración de la exposición de la fruta al 1-MCP (Abdi et al., 1998, Cantin et al., 2011), la temperatura de la fruta al momento de la aplicación del 1-MCP (Abdi et al., 1998; Cantin et al., 2011) y el momento de la aplicación con distintas dosis (Boquete et al., 2004; Menniti et al., 2005). Por otra parte, la modificación de la composición gaseosa del ambiente en el que se encuentra almacenado el fruto es otra herramienta que permite retrasar los cambios asociados a la maduración. La atmósfera controlada (AC) consiste en realizar un exhaustivo control de las concentraciones de O2 y CO2 del entorno gaseoso del producto mediante el empleo de equipamiento adecuado. En kiwi se recomienda modificar los niveles de gases existentes en el aire (78,0 % de N2 , 20,9 % de O2 , y 0,03 % de CO2 ) a valores de 2 % de O2 y 5 % de CO2 , removiendo el etileno para mantener una concentración por debajo de 0,001 µl L-1 (Arpaia et al., 1986). Estos cambios en la composición gaseosa tienen efectos muy importantes sobre el mantenimiento de la firmeza de los frutos (Botondi et al., 2012). En este sentido, Zoffoli et al. (2002) demostraron que la modificación de la atmósfera redujo la tasa de ablandamiento en frutos de kiwi de 0,073 lb/día a 0,006 lb/día a los 52 días de almacenaje a 0 °C. Es escasa la información internacional sobre el uso combinado de AC y 1-MCP. Con la hipótesis de que la AC retrasa la maduración y que su uso combinado con 1-MCP tiene un efecto sinérgico sobre el ablandamiento y un efecto residual cuando la fruta es transferida a temperatura ambiente durante su comercialización, el objetivo de este trabajo fue evaluar el uso de la atmósfera controlada, combinada o no con la aplicación de 1-MCP, y su efecto sobre distintos índices de calidad en frutos de kiwi Haywardproducidos en el sudeste de la provincia de Buenos Aires. Los resultados muestran que el almacenamiento en AC y la aplicación de 1-MCP permiten retener la firmeza de la pulpa del kiwi y prolongar su guarda, aunque su combinación no sería recomendable por producir una desincronización del proceso normal de ablandamiento de la pulpa y la columela. El contenido de AA se mantuvo estable durante el almacenamiento hasta los 7 meses de guarda, ya a partir del mes 8 comenzó a disminuir, aunque no en una magnitud considerable.Fil: Quillehauquy, Victoria. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Baeza, María Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Yommi, A.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Moreno, A.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Fasciglione, Gabriela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin
Phosphites (Phi) have the ability to protect plants against different pathogens, both through a d... more Phosphites (Phi) have the ability to protect plants against different pathogens, both through a direct effect in oomycete metabolism and by an indirect effect stimulating the plant ́s natural defence responses. We have previously shown that KPhi foliar application to potato plants resulted in different protection levels against Phytophthora infestans depending on dose and plant age at application time. In order to identify genes that are involved in induced resistant in plants treated with KPhi, we analyzed by RT PCR, the time course of transcript levels of two genes which encode predicted transcription factors involved in pathogen perception and defence gene expression. Preliminary results showed that WRKY and NPR1 were differentially induced in plants both treated with Phi and infected with Phytophthora infestans, showing an earlier and highest induction than infected plants non treated with Phi. These results may allow us to hypothetize that Phi treatment might trigger a fast mec...
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
The potato periderm is the outer tissue of potato tubers that protects the tuber from pathogen at... more The potato periderm is the outer tissue of potato tubers that protects the tuber from pathogen attack, dehydration, and wounding during harvest and storage. It is of secondary origin and replaces the epidermis early during tuber development. The outer layers of the periderm consist of cells with suberized walls. Phosphite compounds (Phi) are inorganic salts from phosphorous acid, and in previous works, we demonstrated that they are effective in protecting potato plants from biotic stress caused by different pathogens and also against UV-B radiation. The aim of the present work was to study the effect of Phi on the post-harvest potato periderm structure, cell wall components, and related enzymes. In three years of field experiments, potassium phosphite (KPhi) applications were compared with an untreated control. KPhi was applied to seed tubers before planting combined with foliage application of a conventional fungicide, to seed tubers and foliage without conventional fungicide, or to seed tubers combined with foliage application of KPhi plus a conventional fungicide. Observations of periderm sections showed increases in suberin and pectin depositions in post-harvest tubers from KPhi-treated plants compared to tubers from non-treated plants. In addition, peroxidase activity increased in the periderm tissue. The activity of laccases and superoxide dismutase was measured in the protein extract of the periderm, and an increase due to KPhi treatment was detected. The results presented here suggest that early KPhi treatment to seed tubers followed by foliage treatment leads to reinforcement of the cell wall of periderm cells, which represents a benefit for future response to stresses.
Chitosan is obtained at industrial scale through a process of alkaline deacetylation of chitin th... more Chitosan is obtained at industrial scale through a process of alkaline deacetylation of chitin the major waste of shrimp industry. Its utilization could both diminish industrial environmental impact and add value to foods and other industrial products. In this study, an industrial chitosan obtained in Argentina and a commercial chitosan were physicochemically characterized and evaluated as edible coating for biopreservation of minimally processed lettuce. Based on Nuclear Magnetic Resonance, X-ray diffraction and thermogravimetric and viscosimetric assays we conclude that both biopolymers have similar molecular weight and deacetylation degree. The chitosan coatings were applied by spraying to lettuce leaves that had been removed and cleaned after the harvest. Each sample composed by four whole leaves, packed into a low-density polyethylene bag, was stored at 4°C for 15 d. Microbial quality, weight and color losses, antioxidant contents, stomatal closure and sensorial attributes were evaluated during storage. An initial reduction of 2 log in molds and yeast counts were obtained for both types of chitosan coatings. As a result, the counts remained below the limit value of 6 log for 12 d in the chitosan coatings, while in the control samples this limit was reached 6 d after storage. Total mesophilic bacteria counts were also reduced by both types of chitosan coatings, keeping counts under the threshold value of 7 log for 12 d while in control samples this value was exceeded at 9 d. Both chitosans increased chlorophyll content, total phenolic compounds and antioxidant activity in lettuce leaves during the storage. Besides, the leaf weight loss was minimized by both chitosan coatings, in accordance to a higher proportion of stomatal partial closure as seen by SEM. The overall visual quality was not affected by chitosan coatings. In conclusion, the industrial chitosan showed similar effects on stored minimally processed lettuce than the commercial chitosan adding value to a material that is currently considered a waste.
SDRP Journal of Food Science & Technology, 2017
Background: Polyphenols ar e plant metabolites that have been largely studied for their beneficia... more Background: Polyphenols ar e plant metabolites that have been largely studied for their beneficial effect on human health. Potato is one of the most important crops worldwide and is a relevant source of human dietary nutrients and antioxidants. Particularly, pigmented potatoes contain the highest levels of polyphenolic compounds. Hepatocellular carcinoma is one of the most frequent types of cancers worldwide and despite the existence of treatments; it is yet associated with a high mortality rate. Thus, new drugs are needed, and polyphenols are a potential source of antihepatocellular carcinoma compounds. The objectives of this study were to determine the content of different groups of polyphenols (phenolic acids, anthocyanins and flavan-3-ols) in five potato polyphenolic extracts, and to study their antioxidant and cytotoxic activities on a human hepatocellular carcinoma cell line. Methods: four Andean var ieties and one industr ial potato variety were selected for this study. Polyphenolic quantification and composition were determined by spectrophotometric assays and HPLC-DAD analysis. The antioxidant and cytotoxic activities were evaluated through DPPH and MTS assays respectively. Results showed that pigmented var ieties possessed higher levels of the analyzed phenolic compounds. HPLC analysis showed that chlorogenic acid was the main phenolic acid in all the potato polyphenolic extracts. Also, pigmented potatoes presented higher levels of antioxidant activity compared to non-pigmented ones, showing a positive correlation with the total phenolic content. Finally, treatment with three of the studied potato polyphenolic extracts reduced the viability of Hep3B. Furthermore, one extract from a nonpigmented variety affected cell viability to a similar extent as extracts from pigmented potatoes, suggesting that other compounds, besides anthocyanins, may be responsible of the cytotoxic effect of this polyphenolic extracts. Conclusion: These r esults suggested that polyphenolic compounds present in the Andean potato varieties could be used as a potential source of anti
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