scholarly journals Inhibition of Fungal Appressorium Formation by Pepper (Capsicum annuum) Esterase

2001 ◽  
Vol 14 (1) ◽  
pp. 80-85 ◽  
Author(s):  
Young Soon Kim ◽  
Hyun Hwa Lee ◽  
Moon Kyung Ko ◽  
Chae Eun Song ◽  
Cheol-Yong Bae ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
Capsicum Annuum ◽  
Magnaporthe Grisea ◽  
Dependent Manner ◽  
Appressorium Formation ◽  
Glutathione S Transferase ◽  
Porcine Liver ◽  
Esterase Gene ◽  
Dose Dependent ◽  
Dependent Signaling Pathway

A pepper esterase gene (PepEST) that is highly expressed during an incompatible interaction between pepper (Capsicum annuum) and the anthracnose fungus Colletotrichum gloeosporioides has been previously cloned. Glutathione-S-transferase-tagged recombinant PepEST protein expressed in Escherichia coli showed substrate specificity for p-nitrophenyl esters. Inoculation of compatible unripe pepper fruits with C. gloeosporioides spores amended with the recombinant protein did not cause anthracnose symptoms on the fruit. The recombinant protein has no fungicidal activity, but it significantly inhibits appressorium formation of the anthracnose fungus in a dose-dependent manner. An esterase from porcine liver also inhibited appressorium formation, and the recombinant protein inhibited appressorium formation in the rice blast fungus, Magnaporthe grisea. Inhibition of appressorium formation in M. grisea by the recombinant protein was reversible by treatment with cyclic AMP (cAMP) or 1,16-hexadecanediol. The results suggest that the recombinant protein regulates appressorium formation by modulating the cAMP-dependent signaling pathway in this fungus. Taken together, the PepEST esterase activity can inhibit appressorium formation of C. gloeosporioides, which may result in protection of the unripe fruit against the fungus.

scholarly journals Plasmodium falciparum Phospholipase C Hydrolyzing Sphingomyelin and Lysocholinephospholipids Is a Possible Target for Malaria Chemotherapy

2001 ◽  
Vol 195 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Kentaro Hanada ◽  
Nirianne Marie Q. Palacpac ◽  
Pamela A. Magistrado ◽  
Ken Kurokawa ◽  
Ganesh Rai ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Recombinant Protein ◽  
Phospholipase C ◽  
Dependent Manner ◽  
Glutathione S Transferase ◽  
Trophozoite Stage ◽  
Severe Impairment ◽  
Active Transcription ◽  
Biochemical Analyses ◽  
Dose Dependent

Sphingomyelinase (SMase) is one of the principal enzymes in sphingomyelin (SM) metabolism. Here, we identified a Plasmodium falciparum gene (PfNSM) encoding a 46-kD protein, the amino acid sequence of which is ∼25% identical to that of bacteria SMases. Biochemical analyses of the recombinant protein GST-PfNSM, a fusion protein of the PfNSM product with glutathione-S-transferase, reveal that this enzyme retained similar characteristics in various aspects to SMase detected in P. falciparum–infected erythrocytes and isolated parasites. In addition, the recombinant protein retains hydrolyzing activity not only of SM but also of lysocholinephospholipids (LCPL) including lysophosphatidylcholine and lysoplatelet-activating factor, indicating that PfNSM encodes SM/LCPL-phospholipase C (PLC). Scyphostatin inhibited SM/LCPL-PLC activities of the PfNSM product as well as the intraerythrocytic proliferation of P. falciparum in a dose-dependent manner with ID50 values for SM/LCPL-PLC activities and the parasite growth at 3–5 μM and ∼7 μM, respectively. Morphological analysis demonstrated most severe impairment in the intraerythrocytic development with the addition of scyphostatin at trophozoite stage than at ring or schizont stages, suggesting its effect specifically on the stage progression from trophozoite to schizont, coinciding with the active transcription of PfNSM gene.

scholarly journals Tea saponin reduces the damage of Ectropis obliqua to tea crops, and exerts reduced effects on the spiders Ebrechtella tricuspidata and Evarcha albaria compared to chemical insecticides

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4534 ◽  
Author(s):  
Chi Zeng ◽  
Lingbing Wu ◽  
Yao Zhao ◽  
Yueli Yun ◽  
Yu Peng
Keyword(s):  
Biological Control ◽  
Field Trials ◽  
Control Measures ◽  
Dependent Manner ◽  
Glutathione S Transferase ◽  
Tea Plantation ◽  
Tea Saponin ◽  
Yield And Quality ◽  
Significant Damage ◽  
Dose Dependent

Background Tea is one of the most economically important crops in China. However, the tea geometrid (Ectropis obliqua), a serious leaf-feeding pest, causes significant damage to tea crops and reduces tea yield and quality. Spiders are the most dominant predatory enemies in the tea plantation ecosystem, which makes them potentially useful biological control agents of E. obliqua. These highlight the need for alternative pest control measures. Our previous studies have shown that tea saponin (TS) exerts insecticidal activity against lepidopteran pests. Here, we investigate whether TS represents a potentially new alternative insecticide with no harm to spiders. Methods We investigated laboratory bioactivities and the field control properties of TS solution against E. obliqua. (i) A leaf-dip bioassay was used to evaluate the toxicity of TS to 3rd-instar E. obliqua larvae and effects of TS on the activities of enzymes glutathione-S-transferase (GST), acetylcholinesterase (AChE), carboxylesterase (CES) and peroxidase (POD) of 3rd-instar E. obliqua larvae in the laboratory. (ii) Topical application was used to measure the toxicity of 30% TS (w/v) and two chemical insecticides (10% bifenthrin EC and 50% diafenthiuron SC) to two species of spider, Ebrechtella tricuspidata and Evarcha albaria. (iii) Field trials were used to investigate the controlling efficacy of 30% TS against E. obliqua larvae and to classify the effect of TS to spiders in the tea plantation. Results The toxicity of TS to 3rd-instar E. obliqua larvae occurred in a dose-dependent manner and the LC50 was 164.32 mg/mL. Activities of the detoxifying-related enzymes, GST and POD, increased in 3rd-instar E. obliqua larvae, whereas AChE and CES were inhibited with time by treatment with TS. Mortalities of E. tricuspidata and E. albaria after 48 h with 30% TS treatment (16.67% and 20%, respectively) were significantly lower than those with 10% bifenthrin EC (80% and 73.33%, respectively) and 50% diafenthiuron EC (43.33% and 36.67%, respectively). The highest controlling efficacy of 30% TS was 77.02% at 5 d after treatment, which showed no difference to 10% bifenthrin EC or 50% diafenthiuron SC. 30% TS was placed in the class N (harmless or slightly harmful) of IOBC (International Organization of Biological Control) categories for natural enemies, namely spiders. Conclusions Our results indicate that TS is a botanical insecticide that has a good controlling efficacy in E. obliqua larvae, which suggests it has promise as application in the integrated pest management (IPM) envisaged for tea crops.

scholarly journals RAR1, ROR1, and the Actin Cytoskeleton Contribute to Basal Resistance to Magnaporthe grisea in Barley

2005 ◽  
Vol 18 (5) ◽  
pp. 397-404 ◽  
Author(s):  
Birgit Jarosch ◽  
Nicholas C. Collins ◽  
Nina Zellerhoff ◽  
Ulrich Schaffrath
Keyword(s):  
Cell Wall ◽  
Actin Cytoskeleton ◽  
Magnaporthe Grisea ◽  
Penetration Resistance ◽  
Blast Disease ◽  
Dependent Manner ◽  
Basal Resistance ◽  
Major Resistance Gene ◽  
Cytochalasin E ◽  
Dose Dependent

The fungus Magnaporthe grisea, the causal agent of rice blast disease, is a major pathogen of rice and is capable of producing epidemics on other cultivated cereals, including barley (Hordeum vulgare). We explored the requirements for basal resistance of barley against a compatible M. grisea isolate using both genetic and chemical approaches. Mutants of the RAR1 gene required for the function of major resistance gene-mediated resistance and mutants of the ROR1 and ROR2 genes required for full expression of cell-wall-penetration resistance against powdery mildew pathogens were examined for macroscopic and microscopic alterations in M. grisea growth and symptoms. RAR1 contributed to resistance in epidermis and mesophyll at different stages of fungal infection dependent on the MLO/mlo-5 status. Whereas no ROR2 effect was detected, ROR1 was found to contribute to cell-wall-penetration resistance, at least in the epidermis. Application of the actin agonist cytochalasin E promoted cell wall penetration by M. grisea in a dose-dependent manner, demonstrating an involvement of the actin cytoskeleton in penetration resistance.

scholarly journals Glutathione conjugation of chlorambucil: measurement and modulation by plant polyphenols

1997 ◽  
Vol 325 (2) ◽  
pp. 417-422 ◽  
Author(s):  
Kai ZHANG ◽  
Kim Ping WONG
Keyword(s):  
Colon Adenocarcinoma ◽  
Human Colon ◽  
Thymidine Uptake ◽  
Dependent Manner ◽  
Glutathione S Transferase ◽  
Plant Polyphenols ◽  
Simultaneous Exposure ◽  
Adenocarcinoma Cells ◽  
Combined Action ◽  
Dose Dependent

Chlorambucil (CMB), an anticancer drug, was cytotoxic at concentrations of 5–20 μM to human colon adenocarcinoma cells. It inhibited [14C]thymidine uptake in a dose-dependent manner. Both effects were potentiated by simultaneous exposure of the cells to 10 μM plant polyphenols. In an attempt to explain the possible mechanism of action of the polyphenols in relation to these observations, an HPLC-radiometric method was developed to measure the conjugation of CMB with glutathione in these cells and to monitor the export of monochloromonoglutathionyl CMB (MG-CMB), its main glutathione conjugate. At micromolar concentrations, five polyphenols, namely quercetin, butein, tannic acid, 2′-hydroxychalcone and morin, inhibited the efflux of CMB significantly; an inhibition of 40% was observed with 10 μM quercetin. The glutathione S-transferase (GST) activity of the cancer cells, measured with 1-chloro-2,4-dinitrobenzene, was also inhibited by the polyphenols. Their combined action on GST and on the efflux of MG-CMB conjugate could provide an enhanced positive modulation of sensitivity of the tumour cells to CMB.

scholarly journals R848 Is Involved in the Antibacterial Immune Response of Golden Pompano (Trachinotus ovatus) Through TLR7/8-MyD88-NF-κB-Signaling Pathway

2021 ◽  
Vol 11 ◽  
Author(s):  
Yongcan Zhou ◽  
Xiaojuan Chen ◽  
Zhenjie Cao ◽  
Jianlong Li ◽  
Hao Long ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Head Kidney ◽  
Dependent Manner ◽  
Trachinotus Ovatus ◽  
Golden Pompano ◽  
Endosomal Acidification ◽  
Immunological Research ◽  
Dose Dependent ◽  
Dependent Signaling Pathway

R848 is an imidazoquinoline compound that is a specific activator of toll-like receptor (TLR) 7/8 and is often used in immunological research in mammals and teleosts. However, the immune responses initiated by R848 through the TLR7/8 pathway in response to bacterial infection remain largely unexplored in teleosts. In the current study, we investigated the antibacterial response and the participating signaling pathway initiated by R848 in golden pompano (Trachinotus ovatus). We found that R848 could stimulate the proliferation of head kidney lymphocytes (HKLs) in a dose-dependent manner, enhance the survival rate of HKLs, and inhibit the replication of bacteria in vivo. However, these effects induced by R848 were significantly reduced when chloroquine (CQ) was used to blocked endosomal acidification. Additionally, an in vivo study showed that R848 strengthened the antibacterial immunity of fish through a TLR7/8 and Myd88-dependent signaling pathway. A cellular experiment showed that Pepinh-MYD (a Myd88 inhibitor) significantly reduced the R848-mediated proliferation and survival of HKLs. Luciferase activity analysis showed that R848 enhanced the nuclear factor kappa B (NF-κB) activity, whereas this activity was reduced when CQ and Pepinh-MYD were present. Additionally, when an NF-κB inhibitor was present, the R848-mediated pro-proliferative and pro-survival effects on HKLs were significantly diminished. An in vivo study showed that knockdown of TLR7, TLR8, and Myd88 expression in golden pompano via siRNA following injection of R848 resulted in increased bacterial dissemination and colonization in fish tissues compared to that of fish injection of R848 alone, suggesting that R848-induced antibacterial immunity was significantly reduced. In conclusion, these results indicate that R848 plays an essential role in the antibacterial immunity of golden pompano via the TLR7/8-Myd88-NF-κB- signaling pathway.

α-glutathione s-transferase (α-GST) release, an early indicator of carbon tetrachloride hepatotoxicity in the rat

1997 ◽  
Vol 16 (3) ◽  
pp. 154-157 ◽  
Author(s):  
H. Clarke ◽  
DA Egan ◽  
M. Heffernan ◽  
S. Doyle ◽  
C. Byrne ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Dose Response ◽  
Aspartate Aminotransferase ◽  
Statistical Significance ◽  
Dependent Manner ◽  
Glutathione S Transferase ◽  
Cytoplasmic Enzyme ◽  
Enzyme Marker ◽  
Dose Response Study ◽  
Dose Dependent

1 The use of the cytoplasmic enzyme, alpha glutathione s-transferase (α-GST) as an early index of carbon tetrachloride (CCl4) toxicity in the rat was investigated and compared with a standard enzyme marker, aspartate aminotransferase (AST). The hepatotoxic effects of CCl 4 in the rat were determined in a time and dose-response study. 2 Following CCl 4 exposure, α-GST release was shown to be an earlier and more sensitive biomarker of hepatotoxicity than AST. 3 Significant increases in α-GST were detected 2 h after CCl4 exposure. Using the enzyme marker AST, this early hepatotoxic injury went undetected. At 6 and 16 h, α-GST was also a more sensitive indicator of hepatotoxicity than AST. 4 α-GST release was significantly increased at a dose of 5 μl/kg, the lowest concentration of CCl4 administered and clearly responded in a dose-dependent manner with increasing doses of CCl4. In contrast, release of AST did not reach statistical significance until a dose of 25 μl/kg. 5 Thus, these findings indicate that α-GST is a more sensitive and more accurate reflector of CCl4 induced hepatotoxicity than AST.

Chrysin treatment improves diabetes and its complications in liver, brain, and pancreas in streptozotocin-induced diabetic rats

2016 ◽  
Vol 94 (4) ◽  
pp. 388-393 ◽  
Author(s):  
Saeed Samarghandian ◽  
Mohsen Azimi-Nezhad ◽  
Fariborz Samini ◽  
Tahereh Farkhondeh
Keyword(s):  
Total Protein ◽  
Antioxidant Defense ◽  
Diabetic Rats ◽  
Dependent Manner ◽  
Protective Effects ◽  
Significant Elevation ◽  
Glutathione S Transferase ◽  
Defense Systems ◽  
Antioxidant Defense Systems ◽  
Dose Dependent

Chrysin (CH) is a natural flavonoid with pharmacological influences. The purpose of the current study was the assessment of possible protective effects of CH against oxidative damage in the serum, liver, brain, and pancreas of streptozotocin (STZ)- induced diabetic rats. In the present study, the rats were divided into the following groups of 8 animals each: control, untreated diabetic, 3 CH (20, 40, 80 mg/kg/day)-treated diabetic groups. To find out the modulations of cellular antioxidant defense systems, malondialdehyde (MDA) level and antioxidant enzymes including glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities were determined in the serum, liver, brain, and pancreas. STZ caused an elevation of glucose, MDA, TG, TC, LDL-C and with reduction of HDL-C, total protein, SOD, CAT, and GST in the serum, liver, brain, and pancreas (p < 0.01). The findings showed that the significant elevation in the glucose, MDA, TG, TC, LDL-C and reduction of HDL-C, total protein, SOD, CAT, and GST were ameliorated in the CH-treated diabetic groups versus to the untreated groups, in a dose dependent manner (p < 0.05). The current study offers that CH may be recovered diabetes and its complications by modification of oxidative stress.

scholarly journals Curcumin Acetylsalicylate Extends the Lifespan of Caenorhabditis elegans

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6609
Author(s):  
Lei Zhou ◽  
Jin Liu ◽  
Lan-Lan Bu ◽  
Duan-Fang Liao ◽  
Hai-Jun Tu ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Heat Shock ◽  
Nuclear Translocation ◽  
Aging Effect ◽  
Dependent Manner ◽  
Biological Models ◽  
Glutathione S Transferase ◽  
C Elegans ◽  
Dose Dependent ◽  
Stimulation Of

Aspirin and curcumin have been reported beneficial in anti-aging in a variety of biological models. Here, we synthesized a novel compound, curcumin acetylsalicylate (CA), by combining aspirin and curcumin. We characterized how CA affects the lifespan of Caenorhabditis elegans (C. elegans) worms. Our results demonstrated that CA extended the lifespan of worms in a dose-dependent manner and reached its most important anti-aging effect at the concentration of 20 μM. In addition, CA reduced the deposition of lipofuscin or “age pigment” without affecting the reproductivity of worms. CA also caused a rightward shift of C. elegans lifespan curves in the presence of paraquat-induced (5 mM) oxidative stress or 37 °C acute heat shock. Additionally, CA treatment decreased the reactive oxygen species (ROS) level in C. elegans and increased the expression of downstream genes superoxide dismutase (sod)-3, glutathione S-transferase (gst)-4, heat shock protein (hsp)-16.2, and catalase-1 (ctl-1). Notably, CA treatment resulted in nuclear translocation of the DAF-16 transcription factor, which is known for the stimulation of the expression of SOD-3, GST-4, HSP-16, and CTL-1. CA did not produce a longevity effect in daf-16 mutants. In sum, our data indicate that CA delayed the aging of C. elegans without affecting reproductivity, and this effect may be mediated by its activation of DAF-16 and subsequent expressions of antioxidative genes, such as sod-3 and gst-4. Our study suggests that novel anti-aging drugs may be developed by combining two individual drugs.

scholarly journals The NADPH Oxidase Inhibitor Apocynin Suppresses Preneoplastic Liver Foci of Rats

2017 ◽  
Vol 45 (4) ◽  
pp. 544-550 ◽  
Author(s):  
Satoshi Fuji ◽  
Shugo Suzuki ◽  
Aya Naiki-Ito ◽  
Hiroyuki Kato ◽  
Masashi Hayakawa ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Oxidase Inhibitor ◽  
Ros Generation ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Glutathione S Transferase ◽  
Medium Term ◽  
Ki 67 ◽  
Nadph Oxidase Inhibitor ◽  
Dose Dependent

Reactive oxygen species (ROS) have been revealed to be important factors for carcinogenesis and tumor progression. Therefore, we focused on an ROS-generating protein, nicotinamide adenine dinucleotide phosphate oxidase, and evaluated whether its inhibitor, apocynin, could suppress hepatocarcinogenesis in a medium-term rat liver bioassay. The number and size of glutathione S-transferase placental form (GST-P)-positive foci were significantly reduced by apocynin in a dose-dependent manner. The reduction of ROS generation by apocynin was confirmed by dihydroethidium staining. Apocynin treatment also significantly reduced Ki-67 positivity, downregulated cyclooxygenase 2, and suppressed the activation of the c-Myc pathway. Meanwhile, ROS generation was not different between GST-P-positive foci and surrounding GST-P-negative areas of the liver. In conclusion, the present data suggest that apocynin possesses a potential antihepatocarcinogenic property.

scholarly journals Oxidative Stress Induced by Exposure of Microplastics in Labeo Rohita

2021 ◽  
Author(s):  
Rajinder Singh Jandu ◽  
Nisha Vashishat
Keyword(s):  
Oxidative Stress ◽  
Antioxidative Enzymes ◽  
Labeo Rohita ◽  
Time Dependent ◽  
Low Density Polyethylene ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Glutathione S Transferase ◽  
Stress Studies ◽  
Dose Dependent

Abstract The present study revealed the oxidative stress induced by the exposure of low density polyethylene microplastics (LDPE MPs) in Labeo rohita. Fingerlings were divided into four (control, T1, T2 and T3) groups. Fingerlings of T1, T2 and T3 groups were exposed respectively to 2, 20 and 200 mg/L of LDPE MPs for 45 days. A control was also maintained during experiment to which no MPs were added. Oxidative stress studies revealed a decrease in the activity of hepatic antioxidative enzymes i.e. superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) in all treated groups in dose and time dependent manner. In gills, an increase in the activities of SOD, CAT and GPx but decrease in the activities of GR and GST was found in T1 group after 30 days of exposure. However, decrease in activities of these enzymes was observed in all treated groups in dose dependent manner after 45 days of exposure. Moreover, the activities of antioxidative enzymes were found to be decreased in time dependent manner. In kidneys, increase in the activities of antioxidative enzymes was observed in T1 group followed by their decrease in T2 and T3 groups in dose and time dependent manner. However, Lipid peroxidation was found to be increased in vital organs of all treated groups in dose and time dependent manner indicating MPs induced oxidative stress in these organs due to increased production of reactive oxygen species.

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