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1.
Exp Parasitol ; 209: 107810, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31801691

RESUMO

Fasciolosis is a neglected tropical disease caused by the liver fluke Fasciola gigantica. The absence of successful vaccine and emerging resistance in flukes against the drug of choice, triclabendazole, has necessitated the search for alternatives including phyto-therapeutic approaches. Curcumin and thymoquinone, the active ingredients of Curcuma longa and Nigella sativa plants respectively, were first screened for their binding affinity with Glutathione-S-transferase (GST) molecule through in silico molecular docking followed by in vitro treatment of worms with varying concentrations of the test compounds. The in silico molecular docking of curcumin and thymoquinone with sigma GST revealed strong hydrogen bonding as well as hydrophobic interactions with high fitness scores but showing inter-specific differences. The in vitro treatment of F. gigantica worms with both curcumin and thymoquinone resulted in a significant increase in the generation of reactive oxygen species (ROS) whereas the level of reduced glutathione, a primary redox regulator, was found to be significantly decreased (p < 0.05). The two compounds not only inhibited the GST activity, which is an important detoxification enzyme and also a key drug/vaccine target for the control of fasciolosis but also significantly inhibited the activity of antioxidant enzymes glutathione peroxidase and glutathione reductase that are vital in maintenance of redox homeostasis. The immunohistochemistry performed using anti sigma GST polyclonal antibodies revealed that both the compounds used in the present study significantly reduced immunofluorescence in the vitellaria, developing eggs present in the ovary and the intestinal caecae indicating inhibition of GST enzyme in these regions of the worms. Further, following treatment with curcumin and thymoquinone, chromatin condensation and DNA fragmentation was also observed in F. gigantica worms. In conclusion, both curcumin and thymoquinone generated oxidative stress in the worms by production of ROS and significantly inhibiting their antioxidant and detoxification ability. The oxidative stress along with induction of apoptotic like events would compromise the survival ability of worms within the host. However, further studies are required to establish their anthelmintic potential alone and in combination with the commonly used anthelmintic drugs under in vivo conditions.


Assuntos
Apoptose/efeitos dos fármacos , Benzoquinonas/farmacologia , Curcumina/farmacologia , Fasciola/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Benzoquinonas/química , Búfalos , Cromatina/efeitos dos fármacos , Curcumina/química , Dano ao DNA/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Eletroforese em Gel de Ágar , Inibidores Enzimáticos/farmacologia , Fasciola/citologia , Fasciola/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/antagonistas & inibidores , Glutationa Transferase/química , Glutationa Transferase/metabolismo , Imuno-Histoquímica , Microscopia Confocal , Modelos Moleculares , Simulação de Acoplamento Molecular , Espécies Reativas de Oxigênio/metabolismo
2.
Chemotherapy ; 64(3): 138-145, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31639786

RESUMO

BACKGROUND: PD-L1 is a membrane protein with inhibitory effects on immune responses, whose expression has been correlated with high aggressiveness and the propensity of melanoma to metastasize. The nitrobenzoxadiazole (NBD) NBDHEX and its analog MC3181 are endowed with strong antitumor activity towards melanoma and a significant ability to reduce its adhesion and invasiveness. Therefore, we investigated whether PD-L1 status could affect cell sensitivity to the cytotoxic effects of NBDs. We then evaluated the effects of NBDHEX on PD-L1 expression and autophagy in melanoma cells. We used the BRAF-mutated A375 melanoma cell line and an A375 variant population enriched for PD-L1+ cells as a model. The cytotoxic effects of NBDs were evaluated in comparison to those of the BRAF inhibitor vemurafenib and the autophagy inhibitor chloroquine. METHODS: The effect of NBDHEX on autophagy was determined by measuring LC3-II and p62 protein levels by Western blot. The cytotoxic activity of the compounds was evaluated by sulforhodamine B assay. PD-L1 expression and plasma membrane localization were analyzed by FACS and Western blot analysis. RESULTS: NBDHEX behaves as a late-autophagy inhibitor in A375 melanoma cells, as previously found in other tumor cell lines. NBDHEX and MC3181 showed strong and comparable cytotoxic activity in both parental and PD-L1+ A375 cells, with IC50 values in the sub-micromolar range. Conversely, cells sorted for high PD-L1 expression had lower sensitivity to both the BRAF inhibitor vemurafenib and the autophagy inhibitor chloroquine. NBDHEX treatment did not change the total expression and cell surface localization of PD-L1 in both parental and PD-L1+ A375 cells. CONCLUSIONS: Our data suggest that NBDs may represent a promising treatment strategy for melanoma with elevated PD-L1 expression.


Assuntos
Autofagia/efeitos dos fármacos , Antígeno B7-H1/metabolismo , Glutationa Transferase/antagonistas & inibidores , Nitrobenzenos/farmacologia , Oxidiazóis/farmacologia , Antígeno B7-H1/genética , Linhagem Celular Tumoral , Cloroquina/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa Transferase/metabolismo , Humanos , Melanoma , Nitrobenzenos/química , Oxidiazóis/química , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Vemurafenib/farmacologia
3.
Molecules ; 24(16)2019 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-31405214

RESUMO

A series of variously functionalized selenium-containing compounds were purposely synthesized and evaluated against a panel of cancer cell lines. Most of the compounds showed an interesting cytotoxicity profile with compound 5 showing a potent activity on MCF7 cells. The ethyl amino derivative 5 acts synergistically with cis-platin and inhibits the GST enzyme with a potency that well correlates with the cytotoxicity observed in MCF7 cells. A computational analysis suggests a possible binding mode on the GST enzyme. As the main outcome of the present study, the ethyl amino derivative 5 emerged as a valid lead compound for further, future developments.


Assuntos
Antineoplásicos , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos , Glutationa Transferase/antagonistas & inibidores , Proteínas de Neoplasias/antagonistas & inibidores , Compostos Organosselênicos , Compostos de Selênio , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Citotoxinas/síntese química , Citotoxinas/química , Citotoxinas/farmacologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Glutationa Transferase/metabolismo , Células HeLa , Células Endoteliais da Veia Umbilical Humana , Humanos , Células K562 , Células MCF-7 , Proteínas de Neoplasias/metabolismo , Compostos Organosselênicos/síntese química , Compostos Organosselênicos/química , Compostos Organosselênicos/farmacologia , Compostos de Selênio/síntese química , Compostos de Selênio/química , Compostos de Selênio/farmacologia
4.
J Agric Food Chem ; 67(32): 9060-9069, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31339696

RESUMO

Glutathione S-transferases (GSTs) play an active role in the development of drug resistance by numerous cancer cells, including melanoma cells, which is a major cause of chemotherapy failure. As part of our continuous effort to explore why dietary polyphenols bearing the catechol moiety (dietary catechols) show usually anticancer activity, catechol-type diphenylbutadiene (3,4-DHB) was selected as a model of dietary catechols to probe whether they work as pro-oxidative chemosensitizers via GST inhibition in melanoma cells. It was found that, in human melanoma A375 cells, 3,4-DHB is easily converted to its ortho-quinone via copper-containing tyrosinase-mediated two-electron oxidation along with generation of reactive oxygen species (ROS) derived from the oxidation; the resulting ortho-quinone and ROS are responsible for its ability to sensitize the cisplatin-resistant cells by inhibiting GST, followed by induction of apoptosis in an ASK1-JNK/p38 signaling cascade and mitochondria-dependent pathway. This work provides further evidence to support that dietary catechols exhibit antimelanoma activity by virtue of their tyrosinase-dependent pro-oxidative role and gives useful information for designing polyphenol-inspired GST inhibitors and sensitizers in chemotherapy against melanoma.


Assuntos
Antineoplásicos/farmacologia , Butadienos/farmacologia , Catecóis/farmacologia , Inibidores Enzimáticos/farmacologia , Glutationa Transferase/antagonistas & inibidores , Melanoma/enzimologia , Monofenol Mono-Oxigenase/química , Antineoplásicos/química , Antineoplásicos/metabolismo , Apoptose , Butadienos/química , Butadienos/metabolismo , Catecóis/química , Catecóis/metabolismo , Linhagem Celular Tumoral , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Glutationa Transferase/metabolismo , Humanos , Melanoma/metabolismo , Melanoma/fisiopatologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Modelos Químicos , Monofenol Mono-Oxigenase/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
5.
Life Sci ; 231: 116572, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31207309

RESUMO

OBJECTIVES: The aim of this study was to investigate whether some of the cephalosporin group antibiotics have inhibition effects on GR and GST enzymes with important functions in the metabolic pathway. METHODS: In this study, some selected cephalosporin group antibiotics on GST and GR enzyme was carried out using 96 rats. 16 groups (16 × 6) were created from these rats, divided to another 4 groups (4 × 24). The resulting groups were named as sham groups, cefazolin groups, cefuroxime groups and cefoperazone groups, respectively. The antibiotics used were injected to cefazolin, cefuroxime and cefoperazone groups. The inhibition effects of the antibiotics were measured in the different time intervals (1st, 3th, 5th, 7th). The statistical investigation of the results was performed using the SPSS software program. RESULTS: Results revealed the complex effects of the tested substances on GR and GST activity at different time intervals and in different tissues (p < 0.05). This indicated that the tested substances could be exposed to different interactions in vivo. CONCLUSION: The tested antibiotics showed some significant inhibition effects on the GST and GR enzyme activity in some tissues of brain, eye and muscle. The interaction of enzyme - the drug is a key factor to highlight the toxicological mechanism. For this reason, the results obtained from in vivo experiments are crucial to explane the physiological properties of the enzymes.


Assuntos
Cefalosporinas/farmacologia , Glutationa Redutase/antagonistas & inibidores , Glutationa Transferase/antagonistas & inibidores , Animais , Antibacterianos/farmacologia , Cefazolina/farmacologia , Cefoperazona/farmacologia , Cefuroxima/farmacologia , Inibidores Enzimáticos/farmacologia , Glutationa/metabolismo , Glutationa Peroxidase/antagonistas & inibidores , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Ratos
6.
Redox Biol ; 26: 101235, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31202080

RESUMO

Glutathione (GSH), the most abundant vertebrate endogenous redox buffer, plays key roles in organogenesis and embryonic development, however, organ-specific GSH utilization during development remains understudied. Monochlorobimane (MCB), a dye conjugated with GSH by glutathione-s-transferase (GST) to form a fluorescent adduct, was used to visualize organ-specific GSH utilization in live developing zebrafish (Danio rerio) embryos. Embryos were incubated in 20 µM MCB for 1 h and imaged on an epifluorescence microscope. GSH conjugation with MCB was high during early organogenesis, decreasing as embryos aged. The heart had fluorescence 21-fold above autofluorescence at 24 hpf, dropping to 8.5-fold by 48 hpf; this increased again by 72 hpf to 23.5-fold, and stayed high till 96 hpf (18-fold). The brain had lower fluorescence (10-fold) at 24 and 48 hpf, steadily increasing to 30-fold by 96 hpf. The sensitivity and specificity of MCB staining was then tested with known GSH modulators. A 10-min treatment at 48 hpf with 750 µM tert-butylhydroperoxide, caused organ-specific reductions in staining, with the heart losing 30% fluorescence, and, the brain ventricle losing 47% fluorescence. A 24 h treatment from 24-48 hpf with 100 µM of N-Acetylcysteine (NAC) resulted in significantly increased fluorescence, with the brain ventricle and heart showing 312% and 240% increases respectively, these were abolished upon co-treatment with 5 µM BSO, an inhibitor of the enzyme that utilizes NAC to synthesize GSH. A 60 min 100 µM treatment with ethacrynic acid, a specific GST inhibitor, caused 30% reduction in fluorescence across all measured structures. MCB staining was then applied to test for GSH disruptions caused by the toxicants perfluorooctanesulfonic acid and mono-(2-ethyl-hexyl)phthalate; MCB fluorescence responded in a dose, structure and age-dependent manner. MCB staining is a robust, sensitive method to detect spatiotemporal changes in GSH utilization, and, can be applied to identify sensitive target tissues of toxicants.


Assuntos
Encéfalo/metabolismo , Corantes Fluorescentes/química , Glutationa/metabolismo , Pirazóis/química , Coloração e Rotulagem/métodos , Peixe-Zebra/metabolismo , Acetilcisteína/farmacologia , Ácidos Alcanossulfônicos/toxicidade , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Dietilexilftalato/análogos & derivados , Dietilexilftalato/toxicidade , Embrião não Mamífero , Ácido Etacrínico/farmacologia , Fluorcarbonetos/toxicidade , Glutationa Transferase/antagonistas & inibidores , Glutationa Transferase/metabolismo , Coração/efeitos dos fármacos , Coração/crescimento & desenvolvimento , Organogênese/efeitos dos fármacos , Organogênese/fisiologia , Testes de Toxicidade Crônica , Peixe-Zebra/embriologia , Peixe-Zebra/crescimento & desenvolvimento , terc-Butil Hidroperóxido/farmacologia
7.
Arch Insect Biochem Physiol ; 101(2): e21550, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30945781

RESUMO

Black nightshade (Solanum nigrum, S. nigrum L.) and red nightshade ( Solanum villosum, S. villosum Mill.) are medicinal plants from the Solanaceae family that synthesize glycoalkaloids and other secondary metabolites. To recognize the potential insecticide activity of these compounds, leaf extracts (containing glycoalkaloid and methanol fractions) were tested for enzyme inhibition, antifeedant activity and toxicity. For in-vitro glutathione S-transferase (GST) inhibition activity, we used insecticide-resistant Colorado potato beetle, Leptinotarsa decemlineata ( L. decemlineata; Say) midgut and fat-body homogenate. In-vivo toxicity and the antifeedant activity were performed using larval bioassays. The methanol extracts had greater GST inhibitory activity compared to the glycoalkaloids, as well as greater 2nd instar larvae mortality and antifeedant activity. Furthermore, the green leaf volatile compound, cis-hex-3-enyl acetate, at the concentration of 5 ppm, caused 50% mortality of 2nd instar larvae. Our findings suggest the potential usefulness of S. nigrum and S. villosum extracts to control L. decemlineata.


Assuntos
Besouros , Inseticidas , Extratos Vegetais , Solanum/química , Acetatos/toxicidade , Animais , Besouros/enzimologia , Besouros/crescimento & desenvolvimento , Corpo Adiposo/efeitos dos fármacos , Comportamento Alimentar , Glutationa Transferase/antagonistas & inibidores , Larva , Solanum nigrum/química
8.
Chem Commun (Camb) ; 55(30): 4407-4410, 2019 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-30916079

RESUMO

Through systematic target identification for piperlongumine, a cancer-selective killing molecule, we identified GSTO1 as its major covalent target for cancer cell death induction. We also reveal that GSTO1 inhibition is a promising combination strategy with other anti-cancer agents by drug combination screening in which piperlongumine exhibits broad-spectrum synergistic effects with a large proportion of the tested anti-cancer agents, especially with PI3K/Akt/mTOR pathway inhibitors.


Assuntos
Dioxolanos/farmacologia , Glutationa Transferase/metabolismo , Terapia de Alvo Molecular/métodos , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sinergismo Farmacológico , Glutationa Transferase/antagonistas & inibidores , Glutationa Transferase/química , Humanos , Modelos Moleculares , Conformação Proteica
9.
Protein Pept Lett ; 26(5): 364-370, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30827223

RESUMO

BACKGROUND: Natural products are produced via primary and secondary metabolism in different organisms. The compounds obtained via secondary metabolism are not essential for the survival of the organism, but they can have a different value for humans. OBJECTIVE: The objective of this study was to examine inhibitory effects of Usnic Acid (UA), a well-known lichen secondary metabolite, and Carnosic Acid (CA), the primary antioxidant compound of Rosmarinus officinalis L., on purified Human Paraoxonase, (PON1), Glutathione Reductase (GR) and Glutathione S-Transferase (GST). These enzymes have antioxidant properties and a protective effect on the oxidation of free radicals. Hence, deficiencies of such enzymes inside cells can result in a buildup of toxic substances and cause some metabolic disorders. METHODS: UA and CA were tested in various concentrations against human GST, PON1, and GR activity in vitro and they reduced human GST, PON1, and GR activity. RESULTS: UA Ki constants were calculated as 0.012±0.0019, 0.107±0.06 and 0.21±0.1 mM for GST, PON1, and GR enzymes. CA Ki constants were determined as 0.028±0.009, 0.094±0.03 and 0.79±0.33 mM, for GST, PON1, and GR enzymes. UA and CA showed competitive inhibition for GR and GST enzymes, while they exhibited non-competitive inhibition for PON1. CONCLUSION: These findings indicate that UA and CA could be useful in drug development studies.


Assuntos
/química , Antioxidantes/química , Arildialquilfosfatase/antagonistas & inibidores , Benzofuranos/química , Inibidores Enzimáticos/química , Glutationa Redutase/antagonistas & inibidores , Glutationa Transferase/antagonistas & inibidores , Arildialquilfosfatase/química , Glutationa Redutase/química , Glutationa Transferase/química , Humanos , Oxirredução , Rosmarinus
10.
PLoS One ; 14(3): e0214160, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30897163

RESUMO

Equine glutathione transferase A3-3 (EcaGST A3-3) belongs to the superfamily of detoxication enzymes found in all higher organisms. However, it is also the most efficient steroid double-bond isomerase known in mammals. Equus ferus caballus shares the steroidogenic pathway with Homo sapiens, which makes the horse a suitable animal model for investigations of human steroidogenesis. Inhibition of the enzyme has potential for treatment of steroid-hormone-dependent disorders. Screening of a library of FDA-approved drugs identified 16 out of 1040 compounds, which at 10 µM concentration afforded at least 50% inhibition of EcaGST A3-3. The most potent inhibitors, anthralin, sennoside A, tannic acid, and ethacrynic acid, were characterized by IC50 values in the submicromolar range when assayed with the natural substrate Δ5-androstene-3,17-dione.


Assuntos
Inibidores Enzimáticos/farmacologia , Glutationa Transferase/antagonistas & inibidores , Animais , Antralina/farmacologia , Ácido Etacrínico/farmacologia , Glutationa Transferase/metabolismo , Cavalos , Especificidade por Substrato , Taninos/farmacologia
11.
Chem Commun (Camb) ; 55(11): 1596-1599, 2019 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-30656306

RESUMO

Pancreatic cancer has been defined as one of the most complex and challenging cancers to treat, but very few valid therapeutic targets have been identified to date. To address this issue, a 61-compound library was readily created by Ugi reaction followed by phenotypic screening, leading to the discovery of two most potent inhibitors, P21 and P26, which significantly impair BxPC-3 pancreatic cancer cell survival. A series of interacting protein hits, such as GSTO1, FAM213A, RAB6A/6B/39A and USMG5, were subsequently identified by quantitative chemoproteomics studies. The main cellular target, GSTO1, was further validated as a novel pancreatic cancer therapeutic target.


Assuntos
Glutationa Transferase/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/química , Apoptose/efeitos dos fármacos , Sítios de Ligação , Linhagem Celular Tumoral , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Humanos , Simulação de Acoplamento Molecular , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Ligação Proteica , Estrutura Terciária de Proteína , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/uso terapêutico
12.
Food Funct ; 10(2): 573-582, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30694278

RESUMO

Curcumin, bisdemethoxycurcumin and demethoxycurcumin are the main curcuminoids present in Curcuma longa L. and are known for their bioactivity. However, their low water solubility results in poor bioavailability and therapeutic efficacy. This work aimed to investigate the in vitro modulation capacity on the enzymes acetylcholinesterase (AChE) and glutathione S-transferase (GST), as well as the in vitro antioxidant (OxHLIA and TBARS) and anti-inflammatory activities (RAW 264.7 test) of nanoencapsulated curcuminoids. Cytotoxicity on tumor and non-tumor cell lines was also investigated. Curcuminoid nanoparticles significantly inhibited the in vitro activity of AChE (12% inhibition at 50 µM) and GST (30% inhibition at 5 µM). They presented antioxidant activity and toxic effects against breast adenocarcinoma, lung, cervical and hepatocellular carcinoma cells when dispersed in water. Encapsulated curcuminoids exhibited bioactive properties in aqueous medium (no hydrophobic solvent added), exerting antioxidant and cytotoxic effects and acting on the cholinergic and endogenous antioxidant systems.


Assuntos
Anti-Inflamatórios/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Curcuma/química , Nanopartículas/química , Extratos Vegetais/química , Acetilcolinesterase , Animais , Anti-Inflamatórios/química , Antineoplásicos Fitogênicos/química , Antioxidantes/química , Encéfalo/enzimologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Glutationa Transferase/antagonistas & inibidores , Humanos , Camundongos , Células RAW 264.7 , Ratos
13.
Neotrop Entomol ; 48(2): 246-259, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30151672

RESUMO

The migratory locust, Locusta migratoria (Linnaeus), is the most widespread locust species. Frequent applications of insecticides have inevitably resulted in environmental pollution and development of resistance in some natural populations of the locust. To find a new and safe alternative to conventional insecticides, experiments were conducted to assess the effect of olive leaf extracts on L. migratoria fifth instar larvae. The methanolic extracts were prepared from the leaves sampled during four phenological growth stages of olive tree which are as follows: Cluster formation (Cf), Swelling inflorescence buds (Sib), Full flowering (Ff), and Endocarp hardening (Eh). The most relevant result was noted with the extract prepared from the leaves collected at the Sib-stage. Results showed that treatment of newly emerged larvae resulted in a significant mortality with a dose-response relationship. The olive leaf extracts toxicity was also demonstrated by histopathological changes in the alimentary canal resulting in a considerable disorganization and serious damage of the midgut, ceca, and proventriculus structure. Epithelial cells alterations, less dense and degraded striated border, disintegrated regeneration crypts, vacuolarized cells, extrusion of cytoplasmic contents, and rupture of muscular layer were evident in the midgut and ceca of treated larvae. Data of biochemical analyzes showed that olive leaf extracts induced a significant decrease of the hemolymph metabolites (proteins, carbohydrates, and lipids). In a second series of experiments, we showed that the olive leaf extracts reduced the activity of acetylcholinesterase and induced the glutathione S-transferases with a dose-response relationship.


Assuntos
Glutationa Transferase/antagonistas & inibidores , Inseticidas , Locusta migratoria/enzimologia , Olea/química , Extratos Vegetais/química , Acetilcolinesterase , Animais , Inibidores da Colinesterase , Sistema Digestório/patologia , Hemolinfa/química , Larva
14.
Oncol Rep ; 41(2): 989-998, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30431119

RESUMO

The roles of glutathione S­transferase pi 1 (GSTP1), glutathione S­transferase mu 2 (GSTM2) and glutathione S­transferase alpha 1 (GSTA1) in cisplatin (DDP)­resistance of solid cancer cells (A549/DDP, SKOV3/DDP and SGC7901/DDP) were compared following expression downregulation with small interfering RNAs (siRNAs). DDP cytotoxicity was reflected by its half maximal inhibition concentration (IC50) calculated from data using a Cell Counting Kit­8 assay; cell apoptosis was examined using flow cytometry and Hoechst 33342 staining. Higher activities of GST were detected in the cytosol of DDP­resistant cells, compared with those in the parental DDP­susceptible cells. The silencing efficacy of each positive siRNA was supported by western blot analysis. GSTP1 silencing resulted in a 4­fold sensitization of SGC7901/DDP cells to DDP cytotoxicity, but negligible sensitization of SKOV3/DDP and A549/DDP cells. GSTM2 silencing sensitized SKOV3/DDP and A549/DDP cells to DDP cytotoxicity by ~2­fold, but did not sensitize SGC7901/DDP cells. Notably, GSTA1 silencing enhanced DDP cytotoxicity in SGC7901/DDP cells by 6­fold, in A549/DDP cells by 5­fold and in SKOV3/DDP cells by 2­fold. The combined actions of positive siRNAs and DDP increased the percentages of apoptotic cells in the DDP­resistant solid cancer cells compared with the combined actions of DDP and the negative siRNAs. The present findings indicated that GSTA1 is a predominant GST isozyme associated with DDP resistance of SGC7901/DDP, A549/DDP and SKOV3/DDP cells; GSTA1­specific inhibitors may be general sensitizers of SGC7901/DDP, A549/DDP and SKOV3/DDP cells to DDP cytotoxicity through the promotion of cell apoptosis.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , Glutationa Transferase/metabolismo , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Cisplatino/uso terapêutico , Regulação para Baixo , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Regulação Neoplásica da Expressão Gênica , Glutationa Transferase/antagonistas & inibidores , Glutationa Transferase/genética , Humanos , Concentração Inibidora 50 , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , RNA Interferente Pequeno/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Regulação para Cima
15.
Pestic Biochem Physiol ; 152: 90-97, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30497717

RESUMO

Itol A, a novel isoryanodane diterpene derived from Itoa orientalis Hemsl., has potent activities against insect pests. This study was conducted to determine the contact toxicity and biochemical effects of itol A on the Nilaparvata lugens. After macropterous females of N. lugens were exposed to itol A from 0.5 to 24 h, the mortality and poisoning symptoms were measured. Effects of itol A on the major enzymes activity and oxidative stress level were assessed in dose-response (with LD10-LD70 at 24 h) and time-course (with LD50 at 0.5-24 h) experiments for the potential toxicity mechanisms. Based on the results, the mortality of N. lugens showed significant dose- and time-dependent effects, with the 24-h LD50 value was 0.58 µg/insect. The symptoms of excitation, convulsion and paralysis were also observed. However, acetylcholinesterases (AChE) activity was not altered after itol A treatment compared to control. Na+/K+-ATPases, Ca2+-ATPases, Ca2+/Mg2+-ATPases, glutathione S-transferases (GSTs), cytochrome P450 monooxygenases (P450s), superoxide dismutases (SOD) and catalases (CAT) activities were significantly reduced in dose-response and time-course experiments. While acid phosphatases (ACP) and glutathione peroxidases (GPX) activities were significantly increased. We further revealed that itol A exposure resulted in the decrease of GSH/GSSG (reduced to oxidized glutathione) ratio and the increase of hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels in both experiments. The results indicated that the inhibition of Na+/K+-ATPases, Ca2+-ATPases, Ca2+/Mg2+-ATPases, GSTs, P450s, SOD and CAT activities and the induction of oxidative stress was one of the potential biochemical mechanisms of itol A against N. lugens.


Assuntos
Diterpenos/toxicidade , Inibidores Enzimáticos/toxicidade , Hemípteros/efeitos dos fármacos , Inseticidas/toxicidade , Fosfatase Ácida/antagonistas & inibidores , Adenosina Trifosfatases/antagonistas & inibidores , Animais , Diterpenos/química , Inibidores Enzimáticos/química , Feminino , Glutationa/metabolismo , Glutationa Transferase/antagonistas & inibidores , Hemípteros/metabolismo , Inseticidas/química , Dose Letal Mediana , Malondialdeído/metabolismo , Oxirredutases/antagonistas & inibidores , Salicaceae
16.
Int J Mol Sci ; 19(12)2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30487385

RESUMO

Multifunctional enzymes glutathione transferases (GSTs) are involved in the development of chemoresistance, thus representing a promising target for a novel approach in cancer treatment. This superfamily of polymorphic enzymes exhibits extraordinary substrate promiscuity responsible for detoxification of numerous conventional chemotherapeutics, at the same time regulating signaling pathways involved in cell proliferation and apoptosis. In addition to upregulated GST expression, different cancer cell types have a unique GST signature, enabling targeted selectivity for isoenzyme specific inhibitors and pro-drugs. As a result of extensive research, certain GST inhibitors are already tested in clinical trials. Catalytic properties of GST isoenzymes are also exploited in bio-activation of specific pro-drugs, enabling their targeted accumulation in cancer cells with upregulated expression of the appropriate GST isoenzyme. Moreover, the latest approach to increase specificity in treatment of solid tumors is development of GST pro-drugs that are derivatives of conventional anti-cancer drugs. A future perspective is based on the design of new drugs, which would selectively target GST overexpressing cancers more prone to developing chemoresistance, while decreasing side effects in off-target cells.


Assuntos
Inibidores Enzimáticos/uso terapêutico , Glutationa Transferase/antagonistas & inibidores , Glutationa Transferase/metabolismo , Animais , Resistencia a Medicamentos Antineoplásicos , Humanos , Pró-Fármacos/uso terapêutico , Ligação Proteica
17.
Cell Mol Biol (Noisy-le-grand) ; 64(13): 69-73, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30403598

RESUMO

Glutathione-S-transferase also referred as GST is one of the major detoxification enzymes in parasitic helminths. The crucial role played by GST in various chronic infections has been well reported. The dependence of nematodes on detoxification enzymes to maintain their survival within the host established the crucial role of GST in filariasis and other related diseases. Hence, this well-established role of GST in filariasis along with its greater nonhomology with its human counterpart makes it an important therapeutic drug target. Here in this study, we have tried to explore the inhibitory potential of some of the well-reported natural ant-filarial compounds against the GST from Wuchereria bancrofti (W.bancrofti) and Brugia malayi (B.malayi). In silico virtual screening, approach was used to screen the selected natural compounds against GST from W.bancrofti and B.malayi. On the basis of our results, here we are reporting some of the natural compounds which were found to be very effective against GSTs. Along with we have also revealed the characteristic of the active site of BmGST and WbGST and the role of important active site residues involve in the binding of natural compounds within the active site of GSTs. This information will oped doors for using natural compounds as anti-filarial therapy and will also be helpful for future drug discovery.


Assuntos
Anti-Helmínticos/análise , Anti-Helmínticos/farmacologia , Produtos Biológicos/análise , Produtos Biológicos/farmacologia , Brugia Malayi/enzimologia , Avaliação Pré-Clínica de Medicamentos , Glutationa Transferase/antagonistas & inibidores , Wuchereria bancrofti/enzimologia , Alcaloides/química , Alcaloides/farmacologia , Animais , Benzodioxóis/química , Benzodioxóis/farmacologia , Brugia Malayi/efeitos dos fármacos , Capsaicina/química , Capsaicina/farmacologia , Domínio Catalítico , Curcumina/química , Curcumina/farmacologia , Glutationa Transferase/metabolismo , Simulação de Acoplamento Molecular , Piperidinas/química , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/química , Alcamidas Poli-Insaturadas/farmacologia , Estricnina/química , Estricnina/farmacologia , Wuchereria bancrofti/efeitos dos fármacos
18.
Biochem Biophys Res Commun ; 505(4): 979-984, 2018 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-30297111

RESUMO

The notoriety of parasitic nematode survival is directly related to chronic pathogenicity, which is evident in human lymphatic filariasis. It is a disease of poverty which causes severe disability affecting more than 120 million people worldwide. These nematodes down-regulate host immune system through a myriad of strategies that includes secretion of antioxidant and detoxification enzymes like glutathione-S-transferases (GSTs). Earlier studies have shown Wuchereria bancrofti GST to be a potential therapeutic target. Parasite GSTs catalyse the conjugation of glutathione to xenobiotic and other endogenous electrophiles and are essential for their long-term survival in lymph tissues. Hence, the crystal structure of WbGST along with its cofactor GSH at 2.3 Šresolution was determined. Structural comparisons against host GST reveal distinct differences in the substrate binding sites. The parasite xenobiotic binding site is more substrate/solvent accessible. The structure also suggests the presence of putative non-catalytic binding sites that may permit sequestration of endogenous and exogenous ligands. The structure of WbGST also provides a case for the role of the π-cation interaction in stabilizing catalytic Tyr compared to stabilization interactions described for other GSTs. Hence, the obtained information regarding crucial differences in the active sites will support future design of parasite specific inhibitors. Further, the study also evaluates the inhibition of WbGST and its variants by antifilarial diethylcarbamazine through kinetic assays.


Assuntos
Filariose Linfática/tratamento farmacológico , Glutationa Transferase/química , Glutationa Transferase/metabolismo , Wuchereria bancrofti/enzimologia , Animais , Sítios de Ligação/efeitos dos fármacos , Cristalografia por Raios X , Dietilcarbamazina/farmacologia , Filariose Linfática/metabolismo , Glutationa Transferase/antagonistas & inibidores , Humanos , Cinética , Modelos Moleculares , Wuchereria bancrofti/efeitos dos fármacos
19.
Curr Pharm Biotechnol ; 19(11): 925-931, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30370843

RESUMO

BACKGROUND: Glutathione transferases (GSTs) catalyze the conjugation of glutathione (GSH) to endogenous and xenobiotic electrophilic compounds and have been involved in the development of resistance toward cancer chemotherapeutic drugs and in the etiology, pathology and progression of several other diseases. In the present work, the human isoenzyme GSTA1-1 (hGSTA1-1) was used to assemble a microplate-based platform for high-throughput screening of natural productbased inhibitors from plant extracts. METHODS: The enzyme was immobilized using sol-gel chemistry and deposited as a layer at the bottom surface of 96-well format ELISA microplate. The sensing signal was based on the inhibition of the colorimetric reaction between 1-chloro-dinitrobenzene (CDNB) and GSH, catalyzed by the sol-gel entrapped enzyme. RESULTS: As a proof of concept, the system was used for screening aqueous extracts from medicinal and aromatic plants with excellent reproducibility (approximately 95%). CONCLUSION: The operational simplicity and accuracy of this system, suggest that it can be explored as a bioanalytical tool with potential use in drug design and development efforts for finding new sources of GST inhibitors useful in chemomodulation of cancer drugs.


Assuntos
Inibidores Enzimáticos/farmacologia , Enzimas Imobilizadas/antagonistas & inibidores , Glutationa Transferase/antagonistas & inibidores , Extratos Vegetais/farmacologia , Desenho de Drogas , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/isolamento & purificação , Enzimas Imobilizadas/química , Glutationa Transferase/química , Ensaios de Triagem em Larga Escala , Humanos , Extratos Vegetais/isolamento & purificação , Plantas Medicinais/química , Reprodutibilidade dos Testes
20.
Environ Pollut ; 243(Pt B): 1657-1668, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30296762

RESUMO

This study aimed to better understand in situ cumulative effects of anthropogenic stressors on the health of St. Lawrence River (QC, Canada) yellow perch populations using high-throughput transcriptomics and a multi-biological level approach. Fish were collected in the upstream fluvial Lake Saint-François (LSF) with low degree of environmental perturbations; Lake Saint-Louis (LSL) considered having a moderate degree of anthropogenic stressors, and Lake Saint-Pierre (LSP) a sector where the perch population has been severely declining. Morphometric results indicated that fish from the downstream LSP showed lower body condition compared to LSF and LSL. Liver transcriptomic responses were assessed by RNA-sequencing. Two hundred and eighty genes were over-transcribed in LSP perch while 200 genes were under-transcribed compared to LSF and LSL. In LSP fish, genes transcripts related to reproduction, retinol, iron, thyroid hormones, oxidative stress, lipid metabolism and immune functions were among the most abundant suggesting that multiple metabolic and physiological pathways were impacted by environmental stressors at this site. Inhibition of liver superoxide dismutase, catalase and glutathione S-transferase activities were also observed at the cellular level. Overall, identified impacted biological pathways in perch from LSP may help understand the precarious state of this population and identify the factors inhibiting its recovery.


Assuntos
Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Percas/genética , Percas/fisiologia , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Animais , Canadá , Catalase/antagonistas & inibidores , Catalase/genética , Catalase/metabolismo , Perfilação da Expressão Gênica , Glutationa Transferase/antagonistas & inibidores , Sequenciamento de Nucleotídeos em Larga Escala , Lagos , Metabolismo dos Lipídeos/genética , RNA/genética , Rios , Superóxido Dismutase/antagonistas & inibidores , Hormônios Tireóideos/genética , Vitamina A/genética , Vitamina A/metabolismo
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