scholarly journals POLYPHENOLS IN YERBA MATE SEEDS: POTENTIAL INHIBITORS OF GERMINATION

FLORESTA ◽  
2018 ◽  
Vol 48 (4) ◽  
pp. 593
Author(s):  
Maria Cecília Mireski ◽  
Cristiane Vieira Helm ◽  
Ivar Wendling ◽  
Elisa Serra Negra ◽  
Álvaro Figueredo Dos Santos ◽  
...  

Due to its economic, social, and ecological potentials, yerba mate can be a source of employment and income in the southern region of Brazil. The objectives of the present study was to (1) quantify the total polyphenols in fresh yerba mate seeds (FS), seeds dehydrated for 70 d (SD), and seeds stratified in sand for 180 d (SS); (2) evaluate the potential germination and growth inhibitory effects of water, ethanol + water (1:1), and ethanol (99%) extracts of yerba seeds (FS, SD, and SS) using lettuce seedlings; and (3) verify the presence of polyphenols in fresh seeds of yerba mate through histochemical methods. In the bioassay, extracts of yerba mate seeds were used in the germination of lettuce seeds. For the histochemical analysis, sections of yerba mate seeds were stained with specific dyes. The results revealed that yerba mate fresh seeds contain higher concentration of phenolic compounds, which decreased in dehydrated seeds, and almost no phenolic compound was observed in stratified seeds. The bioassay results showed that the polyphenols present in the extracts of yerba mate seeds resulted in phytotoxic effect on the roots of lettuce seedlings. The histochemical observations revealed the presence of “lignified rough barrier” and phenolic compounds between the endocarp and endosperm of the yerba mate seeds

2019 ◽  
Vol 10 (2) ◽  
pp. 79
Author(s):  
Ilori Olasupo John ◽  
Olutobi Oluwafunmilayo Otusanya

A large number of plants impose inhibitory effects on the germination and growth of neighbouring or successional plants by releasing allelochemicals into the soil. This study investigated the phytotoxic effects of Tithonia rotundifolia (Miller) S.F.Blake on the chlorophyll and protein contents of Vigna unguiculata (L.) Walpers and Zea mays L.. This was with a view to determining the susceptibility of these crops to allelochemicals in the extracts prepared from T. rotundifolia. Seeds of the test plants were sown in pots filled with top humus soil. At two weeks, seedlings in each pot were thinned down to 10 seedlings per pot. Potted plants of the test crops were supplied with 400 ml of the appropriate water extracts while the control potted plants were supplied with 400 ml of water. Biochemical analyses were carried out according to standard methods. The data obtained were analysed by (ANOVA) to determine significant (P< 0.05) effects. The means were compared using Duncan Multiple Range Test. The chlorophyll a, chlorophyll b, total chlorophyll and protein contents in V. unguiculata and Z. mays and were significantly inhibited by the extract from T. rotundifolia. The inhibitory effects of these allelochemicals increased with concentration. The phytotoxic effect of T. rotundifolia was species dependent. It was concluded that the extract contains water-soluble allelochemicals which inhibited the biochemical parameters of the test crops. T. rotundifolia should be controlled where it grows in association with cultivated crops.


2007 ◽  
Vol 17 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Daniela Fritz ◽  
Ana Paula Bernardi ◽  
Juliana S. Haas ◽  
Bruna M. Ascoli ◽  
Sérgio Augusto de Loreto Bordignon ◽  
...  

2018 ◽  
Vol 51 (4) ◽  
pp. 36-46
Author(s):  
Z. Muhammad ◽  
N. Inayat ◽  
A. Majeed ◽  

Abstract Allelopathy is an important biological process, which has direct or indirect effects on the germination and growth potentials of plants. Awareness about the allelopathic properties of plants which prevail in agricultural systems can help growers to amend crop cultivation patterns accordingly. In this study, we evaluated the allelopathic effects of Ficus benjamina on germination and early seedling growth of four hybrids of sunflower (Oliver, Parsun-3, SFH-80 and NK-S-278). Ethanolic and hot-water aqueous extracts from leaves, while litter and mulches of the test allelopathic plant significantly reduced germination, radicle and hypocotyle growth of sunflower. Germination percentage was drastically reduced in all the four sunflower hybrids by ethanolic, hot-water and litter extracts; however, compared to control, mulching assay significantly increased germination in hybrids Oliver (76%), Parsun-3 (42%), SFH-80 (78%) and NK-S-278 (30%) at 2, 4, 8 and 12g extract concentration, respectively. Hypocotyle and radicle length of test hybrids were significantly reduced in each assay type. Among tested assays, ethanolic extracts revealed more drastic effects on the studied parameters than hot-water, litter, and mulching. Sunflower hybrid NK-S-278 was more severely affected, while Parsun-3 exhibited resistance to the allelopathic stress. Inhibitory effects were more prominent with increasing concentration of the extracts. The order of the phytotoxic effects of tested bioassays was ethanolic extract˃ hot-water˃ litter˃ mulching. The study suggested that Ficus leaves may possess potent allelochemicals with growth inhibitory effects on sunflower seedlings. It is suggested that further study might be required to check the allelopathic effect of Ficus benjamina on germination and growth of these sunflower hybrids in field conditions.


2019 ◽  
Vol 16 (31) ◽  
pp. 1-8
Author(s):  
Izabela Caputo Assis SILVA ◽  
Juliana Costa FONSECA ◽  
Mairon César COIMBRA ◽  
Joaquim Maurício DUARTE-ALMEIDA ◽  
Luciana Alves Rodrigues dos Santos LIMA

The species Solanum lycocarpum is popularly known as “fruit of the wolf”, and is widely used in traditional medicine. In the present study, the hexane and methanol extracts obtained from the unripe fruits of S. lycocarpum, using a Soxhlet extractor, were evaluated for allelopathic and antioxidant activities. In addition, the content of phenolic compounds and flavonoids was determined. The extracts showed antioxidant activity at the seven concentrations tested. The EC50 values obtained for the extracts could be correlated directly with the content of the phenolic compounds and flavonoids present in the samples. For the allelopathic activity, the samples showed heterogeneous effects on the growth of the hypocotyl and radicle of onion seeds, as well as inhibitory effects against lettuce seeds. These results encourage further studies of this species in order to isolate and identify the compounds responsible for these activities that, in the future, could be used as antioxidants or allelochemicals of a natural origin.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 758
Author(s):  
Hirofumi Yamakawa ◽  
Shuichi Setoguchi ◽  
Shotaro Goto ◽  
Daisuke Watase ◽  
Kazuki Terada ◽  
...  

The first-choice drug for acute promyelocytic leukemia (APL), all-trans retinoic acid (ATRA), frequently causes drug-resistance and some adverse effects. Thus, an effective and safe agent for ATRA-resistant APL is needed. Menaquinone-4 (MK-4, vitamin K2(20)), used for osteoporosis treatment, does not have serious adverse effects. It has been reported that MK-4 has growth-inhibitory effects on HL60 cells by inducing apoptosis via the activation of Bcl-2 antagonist killer 1 (BAK). However, the effect of MK-4 on ATRA-resistant APL has not been reported. Here, we show that ester derivatives of menahydroquinone-4 (MKH; a reduced form of MK-4), MKH 1,4-bis-N,N-dimethylglycinate (MKH-DMG) and MKH 1,4-bis-hemi-succinate (MKH-SUC), exerted strong growth-inhibitory effects even on ATRA-resistant HL60 (HL-60R) cells compared with ATRA and MK-4. MKH delivery after MKH-SUC treatment was higher than that after MK-4 treatment, and the results indicated apoptosis induced by BAK activation. In contrast, for MKH-DMG, reconversion to MKH was slow and apoptosis was not observed. We suggest that the ester forms, including monoesters of MKH-DMG, exhibit another mechanism independent of apoptosis. In conclusion, the MKH derivatives (MKH-SUC and MKH-DMG) inhibited not only HL60 cells but also HL-60R cells, indicating a potential to overcome ATRA resistance.


2021 ◽  
pp. 1-10
Author(s):  
Leandro Marcolino Vieira ◽  
Renata de Almeida Maggioni ◽  
Jéssica de Cássia Tomasi ◽  
Erik Nunes Gomes ◽  
Ivar Wendling ◽  
...  

Abstract Ilex paraguariensis, commonly known as yerba mate, is a tree species native to South America. Its commercial value is due to the manufacturing of teas, with potential also in the pharmacological and cosmetic industries. Vegetative propagation of yerba mate is considered an innovation to the traditional production systems based on sexual propagation. The present study aimed to evaluate the rhizogenic potential and chemical attributes of mini-cuttings from 15 yerba mate genotypes, as well as to verify the correlation between phytochemical and rooting-related variables. Mini-cuttings were collected from a pre-existing mini-clonal hedge and the experimental design was completely randomized, with 15 treatments (genotypes), four replications and 10 mini-cuttings per plot. After 120 days, mini-cuttings were assessed regarding rooting, mortality, callogenesis and leaf retention percentages, percentage of mini-cuttings with both calluses and roots, number of roots and average root length. At the time of collection, subsamples from each plot were used for phytochemical analyses including total phenolic compounds, protein, caffeine and theobromine contents and antioxidant activity. Rooting percentages ranged from 5 to 72.5%, with significant variation among genotypes. Adventitious rooting and phytochemical profile of yerba mate mini-cuttings are genotype-dependent. Leaf retention is a relevant factor in the rooting of yerba mate mini-cuttings and the levels of total phenolic compounds, antioxidants and theobromine present in mini-cuttings are negatively correlated components to Ilex paraguariensis adventitious rooting.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuting Meng ◽  
Xixi Qian ◽  
Li Zhao ◽  
Nan Li ◽  
Shengjie Wu ◽  
...  

Abstract Background The third-generation epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have shown significant therapeutic effects on patients with non-small cell lung carcinoma (NSCLC) who carry active EGFR mutations, as well as those who have developed acquired resistance to the first-generation of EGFR-TKIs due to the T790M mutation. However, most patients develop drug resistance after 8–10 months of treatment. Currently, the mechanism has not been well clarified, and new therapeutic strategies are urgently needed. Methods Osimertinib resistant cell lines were established by culturing sensitive cells in chronically increasing doses of osimertinib. The anticancer effect of reagents was examined both in vitro and in vivo using the sulforhodamine B assay and a xenograft mouse model. The molecular signals were detected by western blotting. The combination effect was analyzed using CompuSyn software. Results We found that bromodomain and extra-terminal proteins (BETs) were upregulated in osimertinib resistant (H1975-OR) cells compared with those in the paired parental cells (H1975-P), and that knockdown of BETs significantly inhibited the growth of H1975-OR cells. The BET inhibitor JQ1 also exhibited stronger growth-inhibitory effects on H1975-OR cells and a greater expression of BETs and the downstream effector c-Myc than were observed in H1975-P cells. The histone deacetylase (HDAC) inhibitor trichostatin A (TSA) showed stronger growth suppression in H1975-OR cells than in H1975-P cells, but vorinostat, another HDAC inhibitor, showed equal inhibitory efficacy in both cell types. Consistently, downregulation of BET and c-Myc expression was greater with TSA than with vorinostat. TSA restrained the growth of H1975-OR and H1975-P xenograft tumors. The combination of TSA and JQ1 showed synergistic growth-inhibitory effects in parallel with decreased BET and c-Myc expression in both H1975-OR and H1975-P cells and in xenograft nude mouse models. BETs were not upregulated in osimertinib resistant HCC827 cells compared with parental cells, while TSA and vorinostat exhibited equal inhibitory effects on both cell types. Conclusion Upregulation of BETs contributed to the osimertinib resistance of H1975 cells. TSA downregulated BET expression and enhanced the growth inhibitory effect of JQ1 both in vitro and in vivo. Our findings provided new strategies for the treatment of osimertinib resistance.


1973 ◽  
Vol 19 (11) ◽  
pp. 1393-1399 ◽  
Author(s):  
Li-Tse Ou ◽  
A. N. Chatterjee ◽  
F. E. Young ◽  
R. E. Marquis

Cell walls isolated from a teichoic acid deficient mutant (52A5) of Staphylococcus aureus strain H were found to have lower capacities to bind cations than did walls of the parent strain. Both types of walls had higher binding affinities for Mg2+ and Ca2+ than for K+ and Na+. The reduced number of phosphate groups in 52A5 walls was reflected in a higher apparent pKa of 4.3 for displacement of Mg2+ (or Ca2+) during acid titration with HCl. The comparable pKa value for displacement of bound Mg2+ from parent-strain walls was 3.7. The reduced capacity of 52A5 walls to bind cations was not reflected in any significant increase in sensitivity to the growth inhibitory actions of ethylenediaminetetraacetate, low pH, or high NaCl concentrations. However, the 52A5 strain was somewhat more sensitive to the inhibitory effects of high pH. Also, mutant walls were found to be structurally more compact than walls of the parent strain, presumably because of less extensive electrostatic repulsion within the wall matrix.


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