scholarly journals Racemoside A, an anti-leishmanial, water-soluble, natural steroidal saponin, induces programmed cell death in Leishmania donovani

2007 ◽  
Vol 56 (9) ◽  
pp. 1196-1204 ◽  
Author(s):  
Avijit Dutta ◽  
Angana Ghoshal ◽  
Debayan Mandal ◽  
Nirup B. Mondal ◽  
Sukdeb Banerjee ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Leishmania Donovani ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Water Soluble ◽  
Asparagus Racemosus ◽  
Steroidal Saponin ◽  
Significant Activity ◽  
Major Health Problem

Leishmaniasis remains a major health problem of the tropical and subtropical world. The visceral form causes the most fatalities if left untreated. Dramatic increases in the rates of infection and drug resistance and the non-availability of safe vaccines have highlighted the need for identification of novel and inexpensive anti-leishmanial agents. This study reports that racemoside A, a water-soluble steroidal saponin purified from the fruits of Asparagus racemosus, is a potent anti-leishmanial molecule effective against antimonial-sensitive (strain AG83) and -unresponsive (strain GE1F8R) Leishmania donovani promastigotes, with IC50 values of 1.15 and 1.31 μg ml−1, respectively. Incubation of promastigotes with racemoside A caused morphological alterations including cell shrinkage, an aflagellated ovoid shape and chromatin condensation. This compound exerts its leishmanicidal effect through the induction of programmed cell death mediated by the loss of plasma membrane integrity as detected by binding of annexin V and propidium iodide, loss of mitochondrial membrane potential culminating in cell-cycle arrest at the sub-G0/G1 phase, and DNA nicking shown by deoxynucleotidyltransferase-mediated dUTP end labelling (TUNEL). Racemoside A also showed significant activity against intracellular amastigotes of AG83 and GE1F8R at a 7–8-fold lower dose, with IC50 values of 0.17 and 0.16 μg ml−1, respectively, and was non-toxic to murine peritoneal macrophages up to a concentration of 10 μg ml−1. Hence, racemoside A is a potent anti-leishmanial agent that merits further pharmacological investigation.

scholarly journals Neurotoxic Effect of Flavonol Myricetin in the Presence of Excess Copper

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 845
Author(s):  
Anja Sadžak ◽  
Ignacija Vlašić ◽  
Zoran Kiralj ◽  
Marijana Batarelo ◽  
Nada Oršolić ◽  
...  
Keyword(s):  
Cell Death ◽  
Intracellular Signaling ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Toxic Effects ◽  
Trypan Blue Exclusion ◽  
Atp Production ◽  
Mtt Method ◽  
Biophysical Approach ◽  
Induced Changes

Oxidative stress (OS) induced by the disturbed homeostasis of metal ions is one of the pivotal factors contributing to neurodegeneration. The aim of the present study was to investigate the effects of flavonoid myricetin on copper-induced toxicity in neuroblastoma SH-SY5Y cells. As determined by the MTT method, trypan blue exclusion assay and measurement of ATP production, myricetin heightened the toxic effects of copper and exacerbated cell death. It also increased copper-induced generation of reactive oxygen species, indicating the prooxidative nature of its action. Furthermore, myricetin provoked chromatin condensation and loss of membrane integrity without caspase-3 activation, suggesting the activation of both caspase-independent programmed cell death and necrosis. At the protein level, myricetin-induced upregulation of PARP-1 and decreased expression of Bcl-2, whereas copper-induced changes in the expression of p53, p73, Bax and NME1 were not further affected by myricetin. Inhibitors of ERK1/2 and JNK kinases, protein kinase A and L-type calcium channels exacerbated the toxic effects of myricetin, indicating the involvement of intracellular signaling pathways in cell death. We also employed atomic force microscopy (AFM) to evaluate the morphological and mechanical properties of SH-SY5Y cells at the nanoscale. Consistent with the cellular and molecular methods, this biophysical approach also revealed a myricetin-induced increase in cell surface roughness and reduced elasticity. Taken together, we demonstrated the adverse effects of myricetin, pointing out that caution is required when considering powerful antioxidants for adjuvant therapy in copper-related neurodegeneration.

Two steroidal saponins from Camassia cusickii induce L1210 cell death through the apoptotic mechanism

2001 ◽  
Vol 79 (11) ◽  
pp. 953-958 ◽  
Author(s):  
Ellyawati Candra ◽  
Kimihiro Matsunaga ◽  
Hironori Fujiwara ◽  
Yoshihiro Mimaki ◽  
Yutaka Sashida ◽  
...  
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Chromatin Condensation ◽  
Flow Cytometric Analysis ◽  
Apoptotic Cell Death ◽  
Morphological Observation ◽  
Steroidal Saponin ◽  
Steroidal Saponins ◽  
L1210 Cells

Two steroidal saponins, tigogenin hexasaccharide-1 (TGHS-1, (25R)-5α-spirostan-3β-yl 4-O-[2-O-[3-O- (α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-3-O-[4-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-glucopyranosyl]- β-D-galactopyranoside) and tigogenin hexasaccharide-2 (TGHS-2, (25R)-5α-spirostan-3β-yl 4-O-[2-O-[3-O- (β-D-glucopyranosyl)-β-D-glucopyranosyl]-3-O-[4-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-glucopyranosyl]- β-D-galactopyranoside), were isolated from the fresh bulbs of Camassia cusickii. In murine leukemic L1210 cells, both compounds showed cytotoxicity with an EC50 value of 0.06 µM. The morphological observation revealed that TGHS-1 and TGHS-2 induced shrinkage in cell soma and chromatin condensation, suggesting apoptotic cell death. The cell death was confirmed to be apoptosis by Annexin V binding to phosphatidylserine in the cell membrane and excluding propidium iodide. A typical apoptotic DNA ladder and the cleavage of caspase-3 were observed after treatment with TGHS-1 and TGHS-2. In the presence of both the compounds, cells with sub-G1 DNA content were detected by flow cytometric analysis, indicating that TGHS-1 and TGHS-2 (each EC50 value of 0.1 µM) are the most powerful apoptotic saponins known. These results suggest that TGHS-1 and TGHS-2 induce apoptotic cell death through caspase-3 activation.Key words: steroidal saponin, tigogenin hexasaccharide, apoptosis, DNA fragmentation, murine leukemic L1210 cells.

scholarly journals Mechanisms of programmed cell death

2019 ◽  
Vol 6 (4) ◽  
pp. 156-158
Author(s):  
Abdu-Alhameed A Ali Azzwali ◽  
 Azab Elsayed Azab
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Nuclear Dna ◽  
Chromatin Condensation ◽  
Cell Shrinkage ◽  
Membrane Blebbing ◽  
Development And Aging ◽  
Nuclear Dna Fragmentation ◽  
Dependent Pathway

The present review aims to spotlight on the mechanisms and stages of programmed cell death. Apoptosis, known as programmed cell death, is a homeostatic mechanism that generally occurs during development and aging in order to keep cells in tissue. It can also act as a protective mechanism, for example, in immune response or if cells are damaged by toxin agents or diseases. In cancer treatment, drugs and irradiation used in chemotherapy leads to DNA damage, which results in triggering apoptosis through the p53 dependent pathway in cancer treatment, drugs and irradiation used in chemotherapy leads to DNA damage, which results in triggering apoptosis through the p53 dependent pathway. Corticosteroids can cause apoptotic death in a number of cells. A number of changes in cell morphology are related to the different stages of apoptosis, which includes nuclear DNA fragmentation, cell shrinkage, chromatin condensation, membrane blebbing, and the formation of apoptotic bodies. There are three pathways for apoptosis, the intrinsic (mitochondrial) and extrinsic (death receptor) are the two major paths that are interlinked and that can effect one another. Conclusion: It can be concluded that apoptosis is a homeostatic mechanism that generally occurs during development and aging in order to keep cells in tissue. Drugs and irradiation used in chemotherapy leads to DNA damage, which results in triggering apoptosis through the p53 dependent pathway. The apoptosis, stages are includes nuclear DNA fragmentation, cell shrinkage, chromatin condensation, membrane blebbing, and the formation of apoptotic bodies. There are three pathways for apoptosis.

scholarly journals Expression of a Mitochondrial Peroxiredoxin Prevents Programmed Cell Death in Leishmania donovani

2006 ◽  
Vol 5 (5) ◽  
pp. 861-870 ◽  
Author(s):  
Simone Harder ◽  
Meike Bente ◽  
Kerstin Isermann ◽  
Iris Bruchhaus
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Mitochondrial Membrane ◽  
Leishmania Donovani ◽  
Physiological Role ◽  
Logarithmic Phase ◽  
Insect Vector ◽  
Oxygen Species ◽  
Late Logarithmic Phase

ABSTRACT Leishmania promastigote cells transmitted by the insect vector get phagocytosed by macrophages and convert into the amastigote form. During development and transformation, the parasites are exposed to various concentrations of reactive oxygen species, which can induce programmed cell death (PCD). We show that a mitochondrial peroxiredoxin (LdmPrx) protects Leishmania donovani from PCD. Whereas this peroxiredoxin is restricted to the kinetoplast area in promastigotes, it covers the entire mitochondrion in amastigotes, accompanied by dramatically increased expression. A similar change in the expression pattern was observed during the growth of Leishmania from the early to the late logarithmic phase. Recombinant LdmPrx shows typical peroxiredoxin-like enzyme activity. It is able to detoxify organic and inorganic peroxides and prevents DNA from hydroxyl radical-induced damage. Most notably, Leishmania parasites overexpressing this peroxiredoxin are protected from hydrogen peroxide-induced PCD. This protection is also seen in promastigotes grown to the late logarithmic phase, also characterized by high expression of this peroxiredoxin. Apparently, the physiological role of this peroxiredoxin is stabilization of the mitochondrial membrane potential and, as a consequence, inhibition of PCD through removal of peroxides.

scholarly journals Characterization of Metacaspases with Trypsin-Like Activity and Their Putative Role in Programmed Cell Death in the Protozoan Parasite Leishmania

2007 ◽  
Vol 6 (10) ◽  
pp. 1745-1757 ◽  
Author(s):  
Nancy Lee ◽  
Sreenivas Gannavaram ◽  
Angamuthu Selvapandiyan ◽  
Alain Debrabant
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Leishmania Donovani ◽  
Protozoan Parasite ◽  
Protein Band ◽  
Mrna Levels ◽  
Enzymatic Assays ◽  
Rich Domain ◽  
Axenic Amastigotes

ABSTRACT In this report, we have characterized two metacaspases of Leishmania donovani, L. donovani metacaspase-1 (LdMC1) and LdMC2. These two proteins show 98% homology with each other, and both contain a characteristic C-terminal proline-rich domain. Both genes are transcribed in promastigotes and axenic amastigotes of L. donovani; however, LdMC1 shows increased mRNA levels in axenic amastigotes. An anti-LdMC antibody was obtained and showed reactivity with a single ∼42-kDa protein band in both promastigote and axenic amastigote parasite whole-cell lysates by Western blotting. Pulse-chase experiments suggest that LdMCs are not synthesized as proenzymes, and immunofluorescence studies show that LdMCs are associated with the acidocalcisome compartments of L. donovani. Enzymatic assays of immunoprecipitated LdMCs show that native LdMCs efficiently cleave trypsin substrates and are unable to cleave caspase-specific substrates. Consistently, LdMC activity is insensitive to caspase inhibitors and is efficiently inhibited by trypsin inhibitors, such as leupeptin, antipain, and N α-tosyl-l-lysine-chloromethyl ketone (TLCK). In addition, our results show that LdMC activity was induced in parasites treated with hydrogen peroxide, a known trigger of programmed cell death (PCD) in Leishmania and that parasites overexpressing metacaspases are more sensitive to hydrogen peroxide-induced PCD. These findings suggest that Leishmania metacaspases are not responsible for the caspase-like activities reported in this organism and suggest a possible role for LdMCs as effector molecules in Leishmania PCD.

Extracts of Artemisia annua leaves and seeds mediate programmed cell death in Leishmania donovani

2012 ◽  
Vol 61 (12) ◽  
pp. 1709-1718 ◽  
Author(s):  
Mohammad Islamuddin ◽  
Abdullah Farooque ◽  
B. S. Dwarakanath ◽  
Dinkar Sahal ◽  
Farhat Afrin
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Leishmania Donovani ◽  
Artemisia Annua

270 APOPTOSIS AND ONCOSIS ASSESSMENT IN CRYOPRESERVED MOUSE EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 242
Author(s):  
M. E. O. A. Assumpção ◽  
A. R. S. Coutinho ◽  
W. B. Feitosa ◽  
C. M. Mendes ◽  
R. Simões ◽  
...  
Keyword(s):  
Cell Death ◽  
Liquid Nitrogen ◽  
Caspase 3 ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Water Bath ◽  
Slow Freezing ◽  
Control Group ◽  
Embryo Viability ◽  
Cryopreserved Embryos

Cryopreservation of mammalian embryos is an important tool for the application of reproductive biotechnology. Recent evidence indicates that apoptosis of cryopreserved embryos may be a negative factor for their viability. The aim of this study was to detect apoptosis and to characterize and quantify the embryonic cell death caused by cryopreservation. Mouse morulae were separated to be subjected to two cryopreservation protocols (slow freezing and vitrification) and a control group (fresh). In the slow-freezing procedure, embryos were exposed to 10% ethylene glycol (EG) for 10 min. Straws were placed in a methanol bath at -7�C until it reached -31�C and then plunged and stored in liquid nitrogen. The embryos were thawed in air for 10 s and in a 25�C water bath for 20 s. In the vitrification method, embryos were exposed to 10% and 20% EG for 5 min, followed by 40% EG + 18% Ficoll + 10% sucrose (EFS) for 30 s and then plunged and stored in liquid nitrogen. These embryos were thawed in a 25�C water bath for 20 s. For the cell death evaluation, cell membrane integrity from the fresh and cryopreserved embryos was assessed by Hoechst and propidium iodide (H/PI staining). Morphology and apoptosis were assessed by means of the haematoxylin-eosin staining (HE) and by electron microscopy (MET). To confirm apoptosis, 64 cryopreserved mouse morulae (34 submitted to slow freezing and 30 to vitrification) were used to evaluate Caspase-3 activity. The cryopreserved embryos were divided into experimental and control groups and incubated with Caspase-3 and buffer solution, respectively. Afterward, the embryos were incubated with rhodamine and the Caspase activity was determined under a fluorescence microscope. H/PI staining detected more membrane permeability in the vitrification (69.7%) than in the slow-freezing (48.4%) or fresh (13.8%) groups (P < 0.05; Wilcoxon's test). Nuclear evaluation by HE revealed that vitrification and slow freezing induced pyknosis and chromatin condensation. HE staining revealed weakly staining cytoplasm and degenerated cells in the vitrification group (indicating oncosis), whereas in the slow-freezing the presence of cytoplasmic condensation and eosinophilic structures indicating apoptosis were observed. MET examination of the ultrastructure confirmed the HE results. The Caspase-3 activity showed a fluorescence increase in both experimental groups compared with the control group. In conclusion, staining with HE allows detection of oncosis and apoptosis in cryopreserved embryos. Regarding the cryopreservation techniques, both slow freezing and vitrification showed oncosis and apoptosis injuries. However, in this experiment vitrification caused more cellular injuries, with less embryo viability, than slow freezing. This work was supported by FAPESP 04/01252-4 and CAPES.

Programmed cell death in Dictyostelium

1994 ◽  
Vol 107 (10) ◽  
pp. 2691-2704 ◽  
Author(s):  
S. Cornillon ◽  
C. Foa ◽  
J. Davoust ◽  
N. Buonavista ◽  
J.D. Gross ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Chromatin Condensation ◽  
In Vitro System ◽  
The Core ◽  
Mechanical Constraints ◽  
Propidium Iodide Staining ◽  
Temporal Succession ◽  
Phenotypic Variations

Programmed cell death (PCD) of Dictyostelium discoideum cells was triggered precisely and studied quantitatively in an in vitro system involving differentiation without morphogenesis. In temporal succession after the triggering of differentiation, PCD included first an irreversible step leading to the inability to regrow at 8 hours. At 12 hours, massive vacuolisation was best evidenced by confocal microscopy, and prominent cytoplasmic condensation and focal chromatin condensation could be observed by electron microscopy. Membrane permeabilization occurred only very late (at 40–60 hours) as judged by propidium iodide staining. No early DNA fragmentation could be detected by standard or pulsed field gel electrophoresis. These traits exhibit some similarity to those of previously described non-apoptotic and apoptotic PCD, suggesting the hypothesis of a single core molecular mechanism of PCD emerging in evolution before the postulated multiple emergences of multicellularity. A single core mechanism would underly phenotypic variations of PCD resulting in various cells from differences in enzymatic equipment and mechanical constraints. A prediction is that some of the molecules involved in the core PCD mechanism of even phylogenetically very distant organisms, e.g. Dictyostelium and vertebrates, should be related.

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