The Experts below are selected from a list of 57 Experts worldwide ranked by ideXlab platform
Ewa Lojkowska - One of the best experts on this subject based on the ideXlab platform.
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Ramentaceone, a Naphthoquinone Derived from Drosera sp., Induces Apoptosis by Suppressing PI3K/Akt Signaling in Breast Cancer Cells.
PloS one, 2016Co-Authors: Anna Kawiak, Ewa LojkowskaAbstract:The phosphoinositide 3-kinase (PI3K) signaling pathway plays an important role in processes critical for breast cancer progression and its upregulation confers increased resistance of cancer cells to chemotherapy and radiation. The present study aimed at determining the activity of Ramentaceone, a constituent of species in the plant genera Drosera, toward breast cancer cells and defining the involvement of PI3K/Akt inhibition in Ramentaceone-mediated cell death induction. The results showed that Ramentaceone exhibited high antiproliferative activity toward breast cancer cells, in particular HER2-overexpressing breast cancer cells. The mode of cell death induced by Ramentaceone was through apoptosis as determined by cytometric analysis of caspase activity and Annexin V staining. Apoptosis induction was found to be mediated by inhibition of PI3K/Akt signaling and through targeting its downstream anti-apoptotic effectors. Ramentaceone inhibited PI3-kinase activity, reduced the expression of the PI3K protein and inhibited the phosphorylation of the Akt protein in breast cancer cells. The expression of the anti-apoptotic Bcl-2 protein was decreased and the levels of the pro-apoptotic proteins, Bax and Bak, were elevated. Moreover, inhibition of PI3K and silencing of Akt expression increased the sensitivity of cells to Ramentaceone-induced apoptosis. In conclusion, our results indicate that Ramentaceone induces apoptosis in breast cancer cells through PI3K/Akt signaling inhibition. These findings suggest further investigation of Ramentaceone as a potential therapeutic agent in breast cancer therapy, in particular HER2-positive breast cancer.
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Ramentaceone a naphthoquinone derived from drosera sp induces apoptosis by suppressing pi3k akt signaling in breast cancer cells
PLOS ONE, 2016Co-Authors: Anna Kawiak, Ewa LojkowskaAbstract:The phosphoinositide 3-kinase (PI3K) signaling pathway plays an important role in processes critical for breast cancer progression and its upregulation confers increased resistance of cancer cells to chemotherapy and radiation. The present study aimed at determining the activity of Ramentaceone, a constituent of species in the plant genera Drosera, toward breast cancer cells and defining the involvement of PI3K/Akt inhibition in Ramentaceone-mediated cell death induction. The results showed that Ramentaceone exhibited high antiproliferative activity toward breast cancer cells, in particular HER2-overexpressing breast cancer cells. The mode of cell death induced by Ramentaceone was through apoptosis as determined by cytometric analysis of caspase activity and Annexin V staining. Apoptosis induction was found to be mediated by inhibition of PI3K/Akt signaling and through targeting its downstream anti-apoptotic effectors. Ramentaceone inhibited PI3-kinase activity, reduced the expression of the PI3K protein and inhibited the phosphorylation of the Akt protein in breast cancer cells. The expression of the anti-apoptotic Bcl-2 protein was decreased and the levels of the pro-apoptotic proteins, Bax and Bak, were elevated. Moreover, inhibition of PI3K and silencing of Akt expression increased the sensitivity of cells to Ramentaceone-induced apoptosis. In conclusion, our results indicate that Ramentaceone induces apoptosis in breast cancer cells through PI3K/Akt signaling inhibition. These findings suggest further investigation of Ramentaceone as a potential therapeutic agent in breast cancer therapy, in particular HER2-positive breast cancer.
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Effects of Ramentaceone on the viability of breast cancer cells.
2016Co-Authors: Anna Kawiak, Ewa LojkowskaAbstract:(A) Cytotoxic activity of Ramentaceone toward HER2-overexpressing (BT474 and SKBR3) and HER2-negative (MCF-7 and MDA-MB-231) breast cancer cells. Cells were treated with Ramentaceone (0–15 μM) for 24 h and cell survival was assessed with the MTT assay (n = 3). (B) Influence of Ramentaceone on clonogenicity of HER2-positive breast cancer cells, SKBR3 and BT474. Cells were treated with Ramentaceone (0–15 μM) for 3 h and allowed to grow for 16 days to form colonies. Values represent mean ± SD of three independent experiments. p < 0.05 (*) indicates differences between control and Ramentaceone-treated cells.
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Induction of apoptosis by Ramentaceone in breast cancer cells.
2016Co-Authors: Anna Kawiak, Ewa LojkowskaAbstract:Apoptotic changes in plasma membrane induced by Ramentaceone. Cells were treated with Ramentaceone (0–15 μM) for 24 h, stained with Annexin V-PE/7-AAD, and analyzed by flow cytometry. Values represent mean ± SD of three independent experiments. p < 0.05 (*) indicates differences between control and Ramentaceone-treated cells.
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Effects of Ramentaceone on expression levels Bcl-2 family proteins and caspase activity in breast cancer cells.
2016Co-Authors: Anna Kawiak, Ewa LojkowskaAbstract:(A) Effects of Ramentaceone on the expression levels of Bax, Bak and Bcl-2 in SKBR3 and BT474 cells. Cells were treated with Ramentaceone (0–15 μM) for 24 h, and the levels of Bax, Bak, Bcl-2 were assessed by Western blot analysis. Protein levels were determined by densitometric analysis (B) Induction of caspase activity in BT474 and SKBR3 cells. Cells were treated with Ramentaceone (0–15 μM) for 12 h, and enzyme activity was determined by flow cytometry with the use of a caspase inhibitor, FAM-VAD-FMK (C) Activation of caspase-3 and cleavage of PARP by Ramentaceone in BT474 and SKBR3 cells. Cells were treated with Ramentaceone (0–15 μM) for 24 h, and the levels of cleaved caspase-3 and PARP were assessed by Western blot analysis. Protein levels were determined by densitometric analysis. Values represent mean ± SD of three independent experiments. p < 0.05 (*) indicates differences between control and Ramentaceone-treated cells.
Anna Kawiak - One of the best experts on this subject based on the ideXlab platform.
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Silver Nanoparticles Combined With Naphthoquinones as an Effective Synergistic Strategy Against Staphylococcus aureus.
Frontiers in pharmacology, 2018Co-Authors: Marta Krychowiak, Anna Kawiak, Magdalena Narajczyk, Agnieszka Borowik, Aleksandra KrolickaAbstract:Staphylococcus aureus is a human pathogen responsible for many antibiotic-resistant infections, for instance burn wound infections, which pose a threat to human life. Exploring possible synergy between various antimicrobial agents, like nanoparticles and plant natural products, may provide new weapons to combat antibiotic resistant pathogens. The objective of this study was to examine the potential of silver nanoparticles (AgNPs) to enhance the antimicrobial activity of selected naphthoquinones (NQs): plumbagin (PL), Ramentaceone (RAM), droserone (DR), and 3-chloroplumbagin (3ChPL). We also attempted to elucidate the mechanism by which the AgNPs enhance the antimicrobial activity of NQs. We analyzed the interaction of AgNPs with bacterial membrane and its effect on membrane stability (TEM analysis, staining with SYTO 9 and propidium iodide), as well as aggregation of NQs on the surface of nanoparticles (UV-Vis spectroscopy and DLS analysis). Our results demonstrated clearly a synergistic activity of AgNPs and three out of four tested NQs (FBC indexes ≤0.375). This resulted in an increase in their combined bactericidal effect towards the S. aureus reference strain and the clinical isolates, which varied in resistance profiles. The synergistic effect (FBC index = 0.375) resulting from combining 3ChPL with silver nitrate used as a control, emphasized the role of the ionic form of silver released from nanoparticles in their bactericidal activity in combination with NQs. The role of membrane damage and AgNPs-NQ interactions in the observed synergy of silver nanoparticles and NQs was also confirmed. Moreover, the described approach, based on the synergistic interaction between the above mentioned agents enables a reduction of their effective doses, thus significantly reducing cytotoxic effect of NQs towards eukaryotic HaCaT cells. Therefore, the present study on the use of a combination of agents (AgNPs-NQs) suggests its potential use as a possible strategy to combat antibiotic-resistant S. aureus.
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Ramentaceone, a Naphthoquinone Derived from Drosera sp., Induces Apoptosis by Suppressing PI3K/Akt Signaling in Breast Cancer Cells.
PloS one, 2016Co-Authors: Anna Kawiak, Ewa LojkowskaAbstract:The phosphoinositide 3-kinase (PI3K) signaling pathway plays an important role in processes critical for breast cancer progression and its upregulation confers increased resistance of cancer cells to chemotherapy and radiation. The present study aimed at determining the activity of Ramentaceone, a constituent of species in the plant genera Drosera, toward breast cancer cells and defining the involvement of PI3K/Akt inhibition in Ramentaceone-mediated cell death induction. The results showed that Ramentaceone exhibited high antiproliferative activity toward breast cancer cells, in particular HER2-overexpressing breast cancer cells. The mode of cell death induced by Ramentaceone was through apoptosis as determined by cytometric analysis of caspase activity and Annexin V staining. Apoptosis induction was found to be mediated by inhibition of PI3K/Akt signaling and through targeting its downstream anti-apoptotic effectors. Ramentaceone inhibited PI3-kinase activity, reduced the expression of the PI3K protein and inhibited the phosphorylation of the Akt protein in breast cancer cells. The expression of the anti-apoptotic Bcl-2 protein was decreased and the levels of the pro-apoptotic proteins, Bax and Bak, were elevated. Moreover, inhibition of PI3K and silencing of Akt expression increased the sensitivity of cells to Ramentaceone-induced apoptosis. In conclusion, our results indicate that Ramentaceone induces apoptosis in breast cancer cells through PI3K/Akt signaling inhibition. These findings suggest further investigation of Ramentaceone as a potential therapeutic agent in breast cancer therapy, in particular HER2-positive breast cancer.
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Ramentaceone a naphthoquinone derived from drosera sp induces apoptosis by suppressing pi3k akt signaling in breast cancer cells
PLOS ONE, 2016Co-Authors: Anna Kawiak, Ewa LojkowskaAbstract:The phosphoinositide 3-kinase (PI3K) signaling pathway plays an important role in processes critical for breast cancer progression and its upregulation confers increased resistance of cancer cells to chemotherapy and radiation. The present study aimed at determining the activity of Ramentaceone, a constituent of species in the plant genera Drosera, toward breast cancer cells and defining the involvement of PI3K/Akt inhibition in Ramentaceone-mediated cell death induction. The results showed that Ramentaceone exhibited high antiproliferative activity toward breast cancer cells, in particular HER2-overexpressing breast cancer cells. The mode of cell death induced by Ramentaceone was through apoptosis as determined by cytometric analysis of caspase activity and Annexin V staining. Apoptosis induction was found to be mediated by inhibition of PI3K/Akt signaling and through targeting its downstream anti-apoptotic effectors. Ramentaceone inhibited PI3-kinase activity, reduced the expression of the PI3K protein and inhibited the phosphorylation of the Akt protein in breast cancer cells. The expression of the anti-apoptotic Bcl-2 protein was decreased and the levels of the pro-apoptotic proteins, Bax and Bak, were elevated. Moreover, inhibition of PI3K and silencing of Akt expression increased the sensitivity of cells to Ramentaceone-induced apoptosis. In conclusion, our results indicate that Ramentaceone induces apoptosis in breast cancer cells through PI3K/Akt signaling inhibition. These findings suggest further investigation of Ramentaceone as a potential therapeutic agent in breast cancer therapy, in particular HER2-positive breast cancer.
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Effects of Ramentaceone on the viability of breast cancer cells.
2016Co-Authors: Anna Kawiak, Ewa LojkowskaAbstract:(A) Cytotoxic activity of Ramentaceone toward HER2-overexpressing (BT474 and SKBR3) and HER2-negative (MCF-7 and MDA-MB-231) breast cancer cells. Cells were treated with Ramentaceone (0–15 μM) for 24 h and cell survival was assessed with the MTT assay (n = 3). (B) Influence of Ramentaceone on clonogenicity of HER2-positive breast cancer cells, SKBR3 and BT474. Cells were treated with Ramentaceone (0–15 μM) for 3 h and allowed to grow for 16 days to form colonies. Values represent mean ± SD of three independent experiments. p < 0.05 (*) indicates differences between control and Ramentaceone-treated cells.
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Induction of apoptosis by Ramentaceone in breast cancer cells.
2016Co-Authors: Anna Kawiak, Ewa LojkowskaAbstract:Apoptotic changes in plasma membrane induced by Ramentaceone. Cells were treated with Ramentaceone (0–15 μM) for 24 h, stained with Annexin V-PE/7-AAD, and analyzed by flow cytometry. Values represent mean ± SD of three independent experiments. p < 0.05 (*) indicates differences between control and Ramentaceone-treated cells.
Aleksandra Krolicka - One of the best experts on this subject based on the ideXlab platform.
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Silver Nanoparticles Combined With Naphthoquinones as an Effective Synergistic Strategy Against Staphylococcus aureus.
Frontiers in pharmacology, 2018Co-Authors: Marta Krychowiak, Anna Kawiak, Magdalena Narajczyk, Agnieszka Borowik, Aleksandra KrolickaAbstract:Staphylococcus aureus is a human pathogen responsible for many antibiotic-resistant infections, for instance burn wound infections, which pose a threat to human life. Exploring possible synergy between various antimicrobial agents, like nanoparticles and plant natural products, may provide new weapons to combat antibiotic resistant pathogens. The objective of this study was to examine the potential of silver nanoparticles (AgNPs) to enhance the antimicrobial activity of selected naphthoquinones (NQs): plumbagin (PL), Ramentaceone (RAM), droserone (DR), and 3-chloroplumbagin (3ChPL). We also attempted to elucidate the mechanism by which the AgNPs enhance the antimicrobial activity of NQs. We analyzed the interaction of AgNPs with bacterial membrane and its effect on membrane stability (TEM analysis, staining with SYTO 9 and propidium iodide), as well as aggregation of NQs on the surface of nanoparticles (UV-Vis spectroscopy and DLS analysis). Our results demonstrated clearly a synergistic activity of AgNPs and three out of four tested NQs (FBC indexes ≤0.375). This resulted in an increase in their combined bactericidal effect towards the S. aureus reference strain and the clinical isolates, which varied in resistance profiles. The synergistic effect (FBC index = 0.375) resulting from combining 3ChPL with silver nitrate used as a control, emphasized the role of the ionic form of silver released from nanoparticles in their bactericidal activity in combination with NQs. The role of membrane damage and AgNPs-NQ interactions in the observed synergy of silver nanoparticles and NQs was also confirmed. Moreover, the described approach, based on the synergistic interaction between the above mentioned agents enables a reduction of their effective doses, thus significantly reducing cytotoxic effect of NQs towards eukaryotic HaCaT cells. Therefore, the present study on the use of a combination of agents (AgNPs-NQs) suggests its potential use as a possible strategy to combat antibiotic-resistant S. aureus.
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In vitro cultures of Drosera aliciae as a source of a cytotoxic naphthoquinone: Ramentaceone
Biotechnology Letters, 2011Co-Authors: Anna Kawiak, Aleksandra Krolicka, Ewa ŁojkowskaAbstract:A protocol for the in vitro propagation of Drosera aliciae to increase the yield of the naphthoquinone, Ramentaceone, was developed. The highest micropropagation coefficient was obtained using half-strength Murashige–Skoog medium supplemented with 0.4 μM 6-benzyladenine (BA). The genetic fidelity and stability of the regenerated plants was confirmed with RAPD markers. The activity of the isolated Ramentaceone was determined against four human tumor cell lines: U937, HeLa, MCF-7, HCT-116 with the highest cytotoxic activity towards the leukemic U937 cell line with an IC_50 value of 3.2 μM.
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Teratomas of Drosera capensis var. alba as a source of naphthoquinone: Ramentaceone
Plant Cell Tissue and Organ Culture (PCTOC), 2010Co-Authors: Aleksandra Krolicka, Anna Szpitter, Krzysztof Stawujak, Rafal Baranski, Anna Gwizdek-wisniewska, Anita Skrzypczak, Marian Kaminski, Ewa LojkowskaAbstract:Plants belonging to genus Drosera (family Droseraceae) contain pharmacologically active naphthoquinones such as Ramentaceone and plumbagin. Hairy root cultures obtained following Agrobacterium rhizogenes -mediated transformation have been reported to produce elevated levels of secondary compounds as well as exhibit desirable rapid biomass accumulation in comparison to untransformed plants. The aim of this study was to establish hairy root or teratoma cultures of Drosera capensis var. alba and to increase the level of Ramentaceone in transformed tissue by application of abiotic and biotic elicitors. The appearance of transformed tissues—teratomas but not hairy roots was observed 18 weeks after transformation. The transformation efficiency was 10% and all teratoma cultures displayed about 3 times higher growth rate than non-transformed cultures of D. capesis . The transformation was confirmed by PCR and Southern hybridization using primers based on the A. rhizogenes rol B and rol C gene sequences. HPLC analysis of Ramentaceone content indicated 60% higher level of this metabolite in teratoma tissue in comparison to non-transformed cultures. Among the elicitors tested jasmonic acid (2.5 mg l^−1) turned out to be the most effective. The productivity of Ramentaceone in elicited teratoma cultures was about sevenfold higher than in liquid cultures of D. capensis var. alba and amounted to 2.264 and 0.321 mg respectively during 4 weeks of cultivation. This is the first report on the transformation of Drosera plant with A. rhizogenes .
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Antibacterial and antioxidant activity of the secondary metabolites from in vitro cultures of the Alice sundew (Drosera aliciae).
Biotechnology and applied biochemistry, 2008Co-Authors: Aleksandra Krolicka, Marian Kaminski, A. Szpitter, Monika Maciag, Edyta Biskup, E. Gilgenast, G. Romanik, Grzegorz Węgrzyn, Ewa LojkowskaAbstract:The objective of the present study was to evaluate the antioxidant as well as the antibacterial properties of secondary metabolites obtained from Drosera aliciae (Alice sundew) plants grown in vitro and to examine the mechanism of their antimicrobial action. Bactericidal activity of extracts from D. aliciae, as well as pure Ramentaceone (naphthoquinone), which is present in this plant, were examined against human pathogenic strains of micro-organisms that are both resistant and susceptible to antibiotics. A chloroform extract proved to be more effective than a methanol preparation against all of the tested strains, except for Pseudomonas aeruginosa isolates. The lowest minimal-bactericidal-concentration value was in the case of Staphylococcus aureus (25―50 mg fresh weight · ml ―I ). The influence of D. aliciae extracts and Ramentaceone on the synthesis of DNA, RNA or proteins in cultures of Enterococcus faecalis was estimated by measurement of the incorporation of the radioactively labelled precursors [ 3 H]thymidine, [ 3 H]uridine or [ 3 H]Ieucine respectively. The methanol extract of D. aliciae, except for a moderate effect on DNA synthesis, had no influence on RNA and protein synthesis. The chloroform preparation caused about a 75 % decrease in [ 3 H]uridine incorporation in comparison with the control after 60 min and a significant diminution in DNA and protein synthesis (44 and 30% respectively). Ramentaceone also decreased DNA and RNA synthesis, but less efficiently than did the chloroform extract, and it caused no changes in [ 3 H]Ieucine incorporation. The methanol extract from D. aliciae proved to be an effective antioxidant in both the DPPH (2,2-diphenyl-I0-picrylhydrazyl free radical) and the FRAP (ferric reducing antioxidant power) assay, with the activities exceeding those of well-known antioxidants, namely the flavonoids. The chloroform extract and Ramentaceone showed no antioxidative properties.
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Stimulation of antibacterial naphthoquinones and flavonoids accumulation in carnivorous plants grown in vitro by addition of elicitors
Enzyme and Microbial Technology, 2008Co-Authors: Aleksandra Krolicka, Marian Kaminski, A. Szpitter, E. Gilgenast, G. Romanik, Ewa LojkowskaAbstract:Abstract Carnivorous plants— Dionaea muscipula and Drosera capensis contain two major groups of pharmaceutically important substances, naphthoquinones: plumbagin, Ramentaceone and flavonoids: myricetin, quercetin, which are considered to be responsible, i.e. for antibacterial properties of preparations from their tissues. This study focused on increasing bactericidal activity of the extracts of in vitro grown D. muscipula and D. capensis by stimulation of secondary metabolite synthesis by application of precursors of phenylpropanoid pathways ( l -phenylalanine or trans -cinnamic acid) and elicitors: jasmonic acid, nitrogen deficiency, lysate of Agrobacterim rhizogenes . HPLC analysis of plant extracts indicated that bacterial lysate was the most successful elicitor of naphthoquinones (2.6-fold increase over control for plumbagin and 1.9 for Ramentaceone). The addition of l -phenylalanine and nitrogen depletion caused the highest accumulation of quercetin (1.6–2 times the control) and myricetin (1.6–1.8 times the control), respectively. The minimal bactericidal concentrations (MBCs) of selected extracts and purified compounds (naphthoquinones and flavonoids) were estimated against hospital isolates of human pathogenic bacteria . The lowest MBC values were observed for methanolic extract from D. muscipula grown on medium with l -phenylalanine (≤25–75 mg FW ml −1 ). These results show the potential of Droseraceae plants grown in vitro as a source of pharmaceutical material with valuable antimicrobial properties.
Marian Kaminski - One of the best experts on this subject based on the ideXlab platform.
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Teratomas of Drosera capensis var. alba as a source of naphthoquinone: Ramentaceone
Plant Cell Tissue and Organ Culture (PCTOC), 2010Co-Authors: Aleksandra Krolicka, Anna Szpitter, Krzysztof Stawujak, Rafal Baranski, Anna Gwizdek-wisniewska, Anita Skrzypczak, Marian Kaminski, Ewa LojkowskaAbstract:Plants belonging to genus Drosera (family Droseraceae) contain pharmacologically active naphthoquinones such as Ramentaceone and plumbagin. Hairy root cultures obtained following Agrobacterium rhizogenes -mediated transformation have been reported to produce elevated levels of secondary compounds as well as exhibit desirable rapid biomass accumulation in comparison to untransformed plants. The aim of this study was to establish hairy root or teratoma cultures of Drosera capensis var. alba and to increase the level of Ramentaceone in transformed tissue by application of abiotic and biotic elicitors. The appearance of transformed tissues—teratomas but not hairy roots was observed 18 weeks after transformation. The transformation efficiency was 10% and all teratoma cultures displayed about 3 times higher growth rate than non-transformed cultures of D. capesis . The transformation was confirmed by PCR and Southern hybridization using primers based on the A. rhizogenes rol B and rol C gene sequences. HPLC analysis of Ramentaceone content indicated 60% higher level of this metabolite in teratoma tissue in comparison to non-transformed cultures. Among the elicitors tested jasmonic acid (2.5 mg l^−1) turned out to be the most effective. The productivity of Ramentaceone in elicited teratoma cultures was about sevenfold higher than in liquid cultures of D. capensis var. alba and amounted to 2.264 and 0.321 mg respectively during 4 weeks of cultivation. This is the first report on the transformation of Drosera plant with A. rhizogenes .
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Antibacterial and antioxidant activity of the secondary metabolites from in vitro cultures of the Alice sundew (Drosera aliciae).
Biotechnology and applied biochemistry, 2008Co-Authors: Aleksandra Krolicka, Marian Kaminski, A. Szpitter, Monika Maciag, Edyta Biskup, E. Gilgenast, G. Romanik, Grzegorz Węgrzyn, Ewa LojkowskaAbstract:The objective of the present study was to evaluate the antioxidant as well as the antibacterial properties of secondary metabolites obtained from Drosera aliciae (Alice sundew) plants grown in vitro and to examine the mechanism of their antimicrobial action. Bactericidal activity of extracts from D. aliciae, as well as pure Ramentaceone (naphthoquinone), which is present in this plant, were examined against human pathogenic strains of micro-organisms that are both resistant and susceptible to antibiotics. A chloroform extract proved to be more effective than a methanol preparation against all of the tested strains, except for Pseudomonas aeruginosa isolates. The lowest minimal-bactericidal-concentration value was in the case of Staphylococcus aureus (25―50 mg fresh weight · ml ―I ). The influence of D. aliciae extracts and Ramentaceone on the synthesis of DNA, RNA or proteins in cultures of Enterococcus faecalis was estimated by measurement of the incorporation of the radioactively labelled precursors [ 3 H]thymidine, [ 3 H]uridine or [ 3 H]Ieucine respectively. The methanol extract of D. aliciae, except for a moderate effect on DNA synthesis, had no influence on RNA and protein synthesis. The chloroform preparation caused about a 75 % decrease in [ 3 H]uridine incorporation in comparison with the control after 60 min and a significant diminution in DNA and protein synthesis (44 and 30% respectively). Ramentaceone also decreased DNA and RNA synthesis, but less efficiently than did the chloroform extract, and it caused no changes in [ 3 H]Ieucine incorporation. The methanol extract from D. aliciae proved to be an effective antioxidant in both the DPPH (2,2-diphenyl-I0-picrylhydrazyl free radical) and the FRAP (ferric reducing antioxidant power) assay, with the activities exceeding those of well-known antioxidants, namely the flavonoids. The chloroform extract and Ramentaceone showed no antioxidative properties.
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Stimulation of antibacterial naphthoquinones and flavonoids accumulation in carnivorous plants grown in vitro by addition of elicitors
Enzyme and Microbial Technology, 2008Co-Authors: Aleksandra Krolicka, Marian Kaminski, A. Szpitter, E. Gilgenast, G. Romanik, Ewa LojkowskaAbstract:Abstract Carnivorous plants— Dionaea muscipula and Drosera capensis contain two major groups of pharmaceutically important substances, naphthoquinones: plumbagin, Ramentaceone and flavonoids: myricetin, quercetin, which are considered to be responsible, i.e. for antibacterial properties of preparations from their tissues. This study focused on increasing bactericidal activity of the extracts of in vitro grown D. muscipula and D. capensis by stimulation of secondary metabolite synthesis by application of precursors of phenylpropanoid pathways ( l -phenylalanine or trans -cinnamic acid) and elicitors: jasmonic acid, nitrogen deficiency, lysate of Agrobacterim rhizogenes . HPLC analysis of plant extracts indicated that bacterial lysate was the most successful elicitor of naphthoquinones (2.6-fold increase over control for plumbagin and 1.9 for Ramentaceone). The addition of l -phenylalanine and nitrogen depletion caused the highest accumulation of quercetin (1.6–2 times the control) and myricetin (1.6–1.8 times the control), respectively. The minimal bactericidal concentrations (MBCs) of selected extracts and purified compounds (naphthoquinones and flavonoids) were estimated against hospital isolates of human pathogenic bacteria . The lowest MBC values were observed for methanolic extract from D. muscipula grown on medium with l -phenylalanine (≤25–75 mg FW ml −1 ). These results show the potential of Droseraceae plants grown in vitro as a source of pharmaceutical material with valuable antimicrobial properties.
Agnieszka Pietrosiuk - One of the best experts on this subject based on the ideXlab platform.
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Hairy Root Cultures for the Production of Anti-cancer Naphthoquinone Compounds.
Current Medicinal Chemistry, 2018Co-Authors: Małgorzata Jeziorek, K. Sykłowska-baranek, Agnieszka PietrosiukAbstract:BACKGROUND: Recent years have brought the dynamic development in studies of naphthoquinones obtained from plants, in vitro cultures and semi- or total synthesis. This review presents the hairy root cultures approach for producing naphthoquinones and summarizes their most recent anti-cancer investigations. OBJECTIVE: This review aimed to define biotechnological strategies impacted on naphthoquinones production in hairy root cultures. Up to now the major source of shikonin/alkannin derivatives, rhinacanthins and Ramentaceone is isolation from plant material, also derived via biotechnological methods. Moreover, the most recent anti-cancer activity studies on naphthoquinones which could be produced in hairy root cultures were outlined. METHODS: For databases survey two selection criteria were used: (i) naphthoquinone could be produced in hairy roots, and (ii) it exhibits anti-cancer properties. RESULTS: Ninety two papers were included in the review, thirty described biotechnological approaches enhancing naphthoquinones production, among them twenty seven were dedicated to hairy root cultures. Forty papers outlined the anti-cancer activity of targeted naphthoquinones including the type of cancer and bioassays description. The synergistic effect of natural naphthoquinones and other anti-cancer therapies was reviewed and toxicity of natural naphthoquinones and plant extracts was discussed. The review highlights tendencies in hairy root investigations and indicates the possible future research directions for improving biotechnological production efficacy. CONCLUSION: This review demonstrates a great potential of hairy root cultures for naphthoquinones production, which could be furtherly developed for future medical purposes, especially as anti-cancer agents. This area of plant biotechnology will be surely still developed with traditional and new strategies.
