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1.
Current Understanding of Leaf Senescence in Rice.
Lee, S, Masclaux-Daubresse, C
International journal of molecular sciences. 2021;(9)
Abstract
Leaf senescence, which is the last developmental phase of plant growth, is controlled by multiple genetic and environmental factors. Leaf yellowing is a visual indicator of senescence due to the loss of the green pigment chlorophyll. During senescence, the methodical disassembly of macromolecules occurs, facilitating nutrient recycling and translocation from the sink to the source organs, which is critical for plant fitness and productivity. Leaf senescence is a complex and tightly regulated process, with coordinated actions of multiple pathways, responding to a sophisticated integration of leaf age and various environmental signals. Many studies have been carried out to understand the leaf senescence-associated molecular mechanisms including the chlorophyll breakdown, phytohormonal and transcriptional regulation, interaction with environmental signals, and associated metabolic changes. The metabolic reprogramming and nutrient recycling occurring during leaf senescence highlight the fundamental role of this developmental stage for the nutrient economy at the whole plant level. The strong impact of the senescence-associated nutrient remobilization on cereal productivity and grain quality is of interest in many breeding programs. This review summarizes our current knowledge in rice on (i) the actors of chlorophyll degradation, (ii) the identification of stay-green genotypes, (iii) the identification of transcription factors involved in the regulation of leaf senescence, (iv) the roles of leaf-senescence-associated nitrogen enzymes on plant performance, and (v) stress-induced senescence. Compiling the different advances obtained on rice leaf senescence will provide a framework for future rice breeding strategies to improve grain yield.
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2.
The pro-apoptotic properties of a phytonutrient rich infusion of A. cherimola leaf extract on AML cells.
Haykal, T, Younes, M, El Khoury, M, Ammoury, C, Tannous, S, Hodroj, MH, Sarkis, R, Gasilova, N, Menin, L, Rizk, S
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 2021;:111592
Abstract
Annonaceae family has broad uses in herbal medicine for treatment of several diseases, whether through seeds' or leaves' extracts. The present study investigates the antiproliferative and antitumor activity of Annona cherimola aqueous leaf (AAL) extract/infusion in acute myeloid leukemia (AML) cell lines in vitro. High-resolution LC-MS was first used to analyze the composition of the aqueous extract. Cell proliferation assay, Annexin V staining, cell cycle analysis, dual Annexin V/PI staining, cell death quantification by ELISA, ROS level detection and Western Blotting were then performed to elucidate the therapeutic effects of AAL extract. The results obtained revealed a potent antioxidant activity of AAL extract. Moreover, the extract exhibited dose- and time-dependent antiproliferative effects on AML cell lines by decreasing cell viability with an IC50 of 5.03% (v/v) at 24 h of treatment of KG-1 cells. This decrease in viability was accompanied with a significant increase in apoptotic cell death with cell cycle arrest and flipping of the phosphatidylserine from the inner to the outer leaflet of the cell membrane. The respective overexpression and downregulation of proapoptotic proteins like cleaved caspase-8, cleaved PARP-1 and Bax and antiapoptotic proteins like Bcl-2 further validated the apoptotic pathway induced by AAL on AML cells. Finally, LC-MS revealed the presence of several compounds like fatty acids, terpenes, phenolics, cinnamic acids and flavonoids that could contribute to the antioxidant and anti-cancer effects of this herbal infusion. In addition to the generally known nutritional effects of the Annona cherimola fruit and leaves, the presented data validates the antioxidant and anti-cancerous effects of the leaf infusion on AML cell lines, proposing its potential therapeutic use against acute myeloid leukemia with future in vivo and clinical trials.
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3.
Polyphenolic Compounds of Crataegus Berry, Leaf, and Flower Extracts Affect Viability and Invasive Potential of Human Glioblastoma Cells.
Żurek, N, Karatsai, O, Rędowicz, MJ, Kapusta, IT
Molecules (Basel, Switzerland). 2021;(9)
Abstract
Crataegus contains numerous health-promoting compounds that are also proposed to have anti-cancer properties. Herein, we aimed at a contemporaneous evaluation of the effects of polyphenol-rich extracts of berries, leaves, and flowers of six Crataegus species on the viability and invasive potential on the highly aggressive human glioblastoma U87MG cell line. The treatment with the extracts evoked cytotoxic effects, with the strongest in the berry extracts. All extracts not only promoted the apoptosis-related cleavage of poly (ADP-ribose) polymerase 1 (PARP1) but also substantially inhibited the activity of pro-survival kinases, focal adhesion kinase (FAK), and protein kinase B (PKB; also known as Akt), thus indicating the suppression of proliferative and invasive potentials of the examined glioblastoma cells. The qualitative and quantitative characterization of the extracts' content was also performed and revealed that amongst 37 polyphenolic compounds identified in the examined Crataegus extracts, the majority (29) was detected in berries; the leaf and flower extracts, exerting milder cytotoxic effects, contained only 14 and 13 compounds, respectively. The highest polyphenol content was found in the berries of C. laevigata x rhipidophylla x monogyna, in which flavan-3-ols and phenolic acids predominated. Our results demonstrated that a high content of polyphenolic compounds correlated with the extract cytotoxicity, and especially berries were a valuable source of compounds with anti-cancer potential. This might be a promising option for the development of an effective therapeutic strategy against highly malignant glioblastomas in the future.
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4.
Genome-wide identification of Pistacia R2R3-MYB gene family and function characterization of PcMYB113 during autumn leaf coloration in Pistacia chinensis.
Song, X, Yang, Q, Liu, Y, Li, J, Chang, X, Xian, L, Zhang, J
International journal of biological macromolecules. 2021;:16-27
Abstract
Pistacia chinensis is known for its biodiesel production. Several varieties of this plant have leaves that produce anthocyanin, which is responsible for their reddish coloration in autumn. This reddish hue is what makes them useful as ornamental plants. However, the mechanism of anthocyanin accumulation during autumn leaf coloration remains unclear. R2R3-MYB proteins reportedly regulated anthocyanin biosynthesis in many plant species. Here, we performed a genome-wide analysis and expression profiles of R2R3-MYB transcription factor in Pistacia. A total of 158 R2R3-MYB proteins were identified and grouped into 32 clades. Combining the data from RNA-seq and qRT-PCR, one key gene, EVM0016534, was screened and identified to have the highest correlation with anthocyanin accumulation. It was named PcMYB113 due to its sequence similarity to AtMYB113 and it could bind to the promoter of PcF3H. Furthermore, ectopic expression of PcMYB113 in Arabidopsis promoted the accumulation of anthocyanin in the seed coat, cotyledon, and mature leaves, thus confirming the function of PcMYB113 in anthocyanin biosynthesis. In addition, PcMYB113 had a specifically higher expression in senesced red leaves than in mature green leaves and young red leaves in P. chinensis, thereby suggesting the potential role of PcMYB113 in promoting anthocyanin biosynthesis during autumn leaf coloration. These findings enrich our understanding of the function of R2R3-MYB genes in anthocyanin biosynthesis and autumn leaf coloration.
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5.
Phenolic compounds from the leaves of Crataegus pinnatifida Bge. var. major N.E.Br. And their lipid-lowering effects.
Pang, X, Wang, M, Wang, SY, Zhang, J, Du, YP, Zhao, Y, Zheng, XH, Ma, BP
Bioorganic & medicinal chemistry letters. 2021;:128211
Abstract
A phytochemical study on the leaves of Crataegus pinnatifida Bge. var. major N.E.Br. was carried out, which finally led to the isolation of nineteen phenolic compounds (1-19). The structures of all compounds were established mainly by NMR and MS spectroscopic analysis as well as the necessary ECD experimental evidence, of which compounds 1-4 (crataegunins A-D) were identified as new phenylpropanoid-substituted epicatechins. HepG2 cells were induced by oleic acid and palmitic acid to establish the model of lipid metabolism disorder. All isolated compounds were used to intervene in the model, and the contents of triglyceride (TG) and total cholesterol (TC) were detected. Compound 2 could significantly reduce the content of TG, while compounds 2 and 11 both have good activity in reducing TC content.
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6.
Chimarrão consumption and prognostic factors in breast cancer: Correlation with antioxidants and blood caffeine levels.
Calixto, MRP, Rech, D, Dos Santos, VL, Madeira, TB, Nixdorf, SL, Fagundes, TR, Davis, RAH, Bastos, FF, Bastos-Neto, JDC, Bastos, VLFDC, et al
Phytotherapy research : PTR. 2021;(2):888-897
Abstract
Breast cancer is the second most common malignancy among women. Ilex paraguariensis A. St. Hil, known as yerba mate, is widely consumed in southern Brazil as a hot infusion drink known as chimarrão. This herb has a complex chemical composition and is rich in antioxidants, which may interfere in the course of chronic inflammatory diseases as breast cancer. This study investigated the impact of chimarrão consumption on the clinicopathological profile of women with breast cancer attended at Francisco Beltrão Cancer Hospital, Paraná, Brazil. Blood antioxidants and caffeine profiles were assessed. Decreases in reduced glutathione and metallothionein levels, and increase in catalase activity were observed among breast cancer patients that were chimarrão consumers. The levels of circulating caffeine in breast cancer patients with luminal A tumors were higher than those in patients with luminal B and HER-2 subtypes. Furthermore, overweight patients presented higher caffeine levels than the eutrophic ones. It was found positive associations between chimarrão intake and high body mass index, and chimarrão intake and menopause at diagnosis. Altogether, these findings suggest that chimarrão consumption affects the blood antioxidants of breast cancer patients, and that the caffeine present in this mixture may favor the development of tumor of good prognosis. HIGHLIGHTS Chimarrão consumption may affect the course of chronic inflammatory diseases, as breast cancer. Chimarrão intake changed blood antioxidants in breast cancer patients who were current consumers when compared to the non-consumers ones. High levels of caffeine were detected in patients bearing luminal A tumors, suggesting a protective role.
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7.
The Olive Leaves Extract Has Anti-Tumor Effects against Neuroblastoma through Inhibition of Cell Proliferation and Induction of Apoptosis.
Morandi, F, Bensa, V, Calarco, E, Pastorino, F, Perri, P, Corrias, MV, Ponzoni, M, Brignole, C
Nutrients. 2021;(7)
Abstract
Neuroblastoma (NB) is the most common extra-cranial solid tumor of pediatric age. The prognosis for high-risk NB patients remains poor, and new treatment strategies are desirable. The olive leaf extract (OLE) is constituted by phenolic compounds, whose health beneficial effects were reported. Here, the anti-tumor effects of OLE were investigated in vitro on a panel of NB cell lines in terms of (i) reduction of cell viability; (ii) inhibition of cell proliferation through cell cycle arrest; (iii) induction of apoptosis; and (iv) inhibition of cell migration. Furthermore, cytotoxicity experiments, by combining OLE with the chemotherapeutic topotecan, were also performed. OLE reduced the cell viability of NB cells in a time- and dose-dependent manner in 2D and 3D models. NB cells exposed to OLE underwent inhibition of cell proliferation, which was characterized by an arrest of the cell cycle progression in G0/G1 phase and by the accumulation of cells in the sub-G0 phase, which is peculiar of apoptotic death. This was confirmed by a dose-dependent increase of Annexin V+ cells (peculiar of apoptosis) and upregulation of caspases 3 and 7 protein levels. Moreover, OLE inhibited the migration of NB cells. Finally, the anti-tumor efficacy of the chemotherapeutic topotecan, in terms of cell viability reduction, was greatly enhanced by its combination with OLE. In conclusion, OLE has anti-tumor activity against NB by inhibiting cell proliferation and migration and by inducing apoptosis.
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8.
Review of the Phytochemistry and Biological Activity of Cissus incisa Leaves.
Nocedo-Mena, D, Galván-Rodrigo, AA, Wright, CW, Caboni, P
Current topics in medicinal chemistry. 2021;(26):2409-2424
Abstract
BACKGROUND Cissus incisa is a Vitaceae with a pantropical distribution. In northern Mexico, its leaves have traditionally been used to treat skin infections, abscesses and tumors. Despite its medicinal uses, few studies have been reported. OBJECTIVE The objective of this study is to summarize the phytochemical and biological studies carried out so far on the leaves of C. incisa, since this part of the plant is the one frequently used, and awaken scientific interest towards the plant. METHODS Since C. incisa was an undocumented species, most of the information comes from reports of our research group. Databases, books, and websites were also consulted. The information collected was organized and presented in a synthesized way. Plant name was checked with the database "The Plant List". RESULTS 171, 260, and 114 metabolites were identified by UHPLC-QFTOF-MS in the hexane, chloroform/ methanol, and aqueous extracts, respectively. Fatty acyls, sphingolipids, sterols, glycerolipids, prenol lipids, and terpenes are common metabolites found in these extracts. 2-(2´-hydroxydecanoyl amino)-1,3,4-hexadecanotriol-8-ene, 2,3-dihydroxypropyl tetracosanoate, β-sitosterol, β-sitosterol-D-glucopyranoside, α-amyrin-3-O-β-D-glucopyranoside were also isolated and characterized. Extracts, phytocompounds and semi-synthetic derivatives showed antimicrobial activity against multi-drug resistant bacteria and various cancer cell lines. Results from Perturbation- Theory-Machine Learning-Information-Fusion model (PTMLIF), molecular docking, and vesicular contents assay identified potential targets on the cell membrane, suggesting an antibacterial mechanism of action for ceramides from C. incisa leaves. CONCLUSION This review reports the efforts of the scientific community in authenticating species used in traditional medicine. Moreover, it gives a compendium of phytochemistry and the biological activities of the components from C. incisa leaves.
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9.
Environment-coupled models of leaf metabolism.
Töpfer, N
Biochemical Society transactions. 2021;(1):119-129
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Abstract
The plant leaf is the main site of photosynthesis. This process converts light energy and inorganic nutrients into chemical energy and organic building blocks for the biosynthesis and maintenance of cellular components and to support the growth of the rest of the plant. The leaf is also the site of gas-water exchange and due to its large surface, it is particularly vulnerable to pathogen attacks. Therefore, the leaf's performance and metabolic modes are inherently determined by its interaction with the environment. Mathematical models of plant metabolism have been successfully applied to study various aspects of photosynthesis, carbon and nitrogen assimilation and metabolism, aided suggesting metabolic intervention strategies for optimized leaf performance, and gave us insights into evolutionary drivers of plant metabolism in various environments. With the increasing pressure to improve agricultural performance in current and future climates, these models have become important tools to improve our understanding of plant-environment interactions and to propel plant breeders efforts. This overview article reviews applications of large-scale metabolic models of leaf metabolism to study plant-environment interactions by means of flux-balance analysis. The presented studies are organized in two ways - by the way the environment interactions are modelled - via external constraints or data-integration and by the studied environmental interactions - abiotic or biotic.
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Metabolic and Anti-Inflammatory Protective Properties of Human Enriched Serum Following Artichoke Leaf Extract Absorption: Results from an Innovative Ex Vivo Clinical Trial.
Wauquier, F, Boutin-Wittrant, L, Viret, A, Guilhaudis, L, Oulyadi, H, Bourafai-Aziez, A, Charpentier, G, Rousselot, G, Cassin, E, Descamps, S, et al
Nutrients. 2021;(8)
Abstract
The aging of our population is accompanied by an increased prevalence of chronic diseases. Among those, liver, joint and adipose tissue-related pathologies have a major socio-economic impact. They share common origins as they result from a dysregulation of the inflammatory and metabolic status. Plant-derived nutrients and especially polyphenols, exert a large range of beneficial effects in the prevention of chronic diseases but require clinically validated approaches for optimized care management. In this study, we designed an innovative clinical approach considering the metabolites produced by the digestive tract following the ingestion of an artichoke leaf extract. Human serum, enriched with metabolites deriving from the extract, was collected and incubated with human hepatocytes, human primary chondrocytes and adipocytes to determine the biological activity of the extract. Changes in cellular behavior demonstrated that the artichoke leaf extract protects hepatocytes from lipotoxic stress, prevents adipocytes differentiation and hyperplasia, and exerts chondroprotective properties in an inflammatory context. These data validate the beneficial health properties of an artichoke leaf extract at the clinical level and provide both insights and further evidence that plant-derived nutrients and especially polyphenols from artichoke may represent a relevant alternative for nutritional strategies addressing chronic disease issues.