Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Ethnopharmacol ; 282: 114592, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34480996

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Different parts of Antiaris africana Englea (Moraceae) are used traditionally for the treatment of various diseases, including epilepsy and other nervous system disorders. AIMS OF THIS STUDY: The current study was designed to evaluate the neuroprotective activity of flavonoids isolated from A. africana against potassium cyanide (KCN)-induced oxidative damage in brain homogenate. MATERIALS AND METHODS: Dried and ground leaves of A. africana were extracted with methanol and fractioned into n-hexane (HFA), dichloromethane (DFA), ethyl acetate (EFA) and methanol (MFA). Each fraction was assessed for neuroprotective potential by anticholinesterase activity test. The fraction with the best anticholinesterase activity was subjected to various chromatographic techniques through bioassay-guided fractionation to isolate the bioactive compounds. The protective ability of the extract, fractions and compounds against Potassium cyanide (KCN)-induced mitochondrial damage in rat brain homogenate was evaluated. Structures of the isolated compounds were determined using 1D and 2D NMR, mass spectrometry and by comparison with literature data. RESULTS AND DISCUSSION: The ethyl acetate fraction showed the best anticholinesterase activity with an IC50 of 23.23 ± 1.12 µg/ml. Quercetin and a biflavonoid glucoside identified as 3'-4'-bisquercetin-3ß-D-diglucoside from this fraction displayed a remarkable antioxidant activity in the DPPH assay and showed significant (P < 0.05) increase in the activity of dehydrogenase inhibited by KCN in a concentration dependent manner. However, quercetin was more effective in reducing the MDA level and acetylcholinesterase activity that were elevated by KCN. CONCLUSION: Quercetin and the bisquercetin-diglucoside isolated from the leaves of A. Africana for the first time, are major contributors to the observed neuroprotective property of the plant which supports its folkloric usage in the management of seizures, epilepsy and other neurological disorders.


Assuntos
Antiaris , Antioxidantes/farmacologia , Inibidores da Colinesterase/farmacologia , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta , Cianeto de Potássio/toxicidade , Quercetina/farmacologia , Animais , Flavonoides/farmacologia , Medicina Tradicional , Doenças do Sistema Nervoso/tratamento farmacológico , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos
2.
Biochem Pharmacol ; 190: 114622, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34043967

RESUMO

Lung cancer is the leading cause of cancer deaths in the world. Non-small cell lung cancer (NSCLC), with poor prognosis and resistance to chemoradiotherapy, is the most common histological type of lung cancer. Therefore, it is necessary to develop new and more effective treatment strategy for NSCLC. Nur77, an orphan member of the nuclear receptor superfamily, induces apoptosis in cancer cells including NSCLC cells, by high expression and translocation to mitochondria. Small molecules trigger expression and mitochondrial localization of Nur77 may be an ideal anti-cancer drug candidate. Here, we report malayoside, a cardiac glycoside in the extract of Antiaris toxicaria Lesch., had different sensitivities to NSCLC cells. Malayoside induced apoptosis in NCI-H460 cells. Meanwhile, malayoside induced Nur77 expression and mitochondrial localization, and its induction of apoptosis was Nur77-dependent. To investigate the molecular mechanism of malayoside inducing Nur77 and apoptosis, we found that malayoside activated MAPK signaling pathway, including both ERK and p38 phosphorylation. The suppression of MAPK signaling activation inhibited the expression of Nur77 and apoptosis induced by malayoside. Our studies in nude mice showed that malayside potently inhibited the growth of tumor cells in vivo. Furthermore, the anti-cancer effect of malayosidwas in vivo was also related to the elevated expression of Nur77, p-ERK, and p-p38 proteins. Our results suggest that malayoside possesses an anti-NSCLC activity in vitro and in vivo mainly via activation of MAPK-Nur77 signaling pathway, indicating that malayoside is a promising chemotherapeutic candidate for NSCLC.


Assuntos
Antiaris/química , Apoptose/efeitos dos fármacos , Glicosídeos Cardíacos/farmacologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas , Glicosídeos Cardíacos/química , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Camundongos , Camundongos Nus , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Fitoterapia , Transporte Proteico/efeitos dos fármacos
3.
Artigo em Inglês | MEDLINE | ID: mdl-31800394

RESUMO

Background The physiopathologies of many neurologic diseases are characterized by related biochemical dysfunctions that could be explored as drug targets. This study evaluated the effect of a methanol leaf extract of Antiaris africana (MEA) on critical bioindices of Parkinsonism and related neurologic dysfunctions in rats with rotenone-induced neurotoxicity. Methods Animals were administered 50 or 100 mg/kg MEA for 14 consecutive days. Rotenone (1.5 mg/kg) was administered three times per day on days 13 and 14. Coenzyme Q10 (5 mg/kg) was the reference drug. Complex I activity, dopamine level, activities of acetylcholinesterase, myeloperoxidase, Na+/K+ ATPase and glutamine synthetase, as well as oxidative stress indices were evaluated at the end of the period of treatment. Results Rotenone-intoxicated group showed disruption of complex 1 activity, dopamine level, and glutamine synthetase activity with negative alterations to activities of acetylcholinesterase, myeloperoxidase, and Na+/K+ ATPase as well as heightened cerebral oxidative stress. MEA restored brain mitochondria functionality, mitigated altered neurochemical integrity, and ameliorated cerebral oxidative stress occasioned by rotenone neurotoxicity. The activity of A. Africana was comparable with that of 5 mg/kg coenzyme Q10. Conclusions These results indicated that A. africana displayed therapeutic potential against Parkinsonism and related neurologic dysfunctions and support its ethnobotanical use for the treatment of neurologic disorders.


Assuntos
Antiaris/química , Doenças do Sistema Nervoso/tratamento farmacológico , Transtornos Parkinsonianos/tratamento farmacológico , Extratos Vegetais/farmacologia , Acetilcolinesterase/metabolismo , Animais , Dopamina/metabolismo , Glutamato-Amônia Ligase/metabolismo , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Doenças do Sistema Nervoso/induzido quimicamente , Doenças do Sistema Nervoso/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/metabolismo , Peroxidase/metabolismo , Ratos , Ratos Wistar , Rotenona/farmacologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Ubiquinona/análogos & derivados , Ubiquinona/metabolismo
4.
Afr J Tradit Complement Altern Med ; 14(4): 253-264, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28638888

RESUMO

BACKGROUND: Oxidative stress plays a significant role in stroke pathogenesis. Hence, plants rich in antioxidant phytochemicals have been suggested as effective remedies for prevention and treatment of stroke and other neurological diseases. Antiaris africana Engl. (Moraceae) is traditionally used for the management of brain-related problems but there is paucity of data on its anti-stroke potential. MATERIALS AND METHODS: Ischemia/reperfusion injury was induced by a 30 min bilateral common carotid artery occlusion/ 2 h reperfusion (BCCAO/R) in the brain of male Wistar rats. A sham-operated group which was not subjected to BCCAO/R and a group subjected to BCCAO/R without treatment with MEA served as controls. The ameliorative effect of 14 days of pretreatment with 50 mg/kg or 100 mg/kg A. africana methanol leaf extract (MEA) on BCCAO/R-mediated alterations to key markers of oxidative stress (malondialdehyde, reduced glutathione, xanthine oxidase, superoxide dismutase, catalase and glutathione peroxidase) and neurochemical disturbances and excitotoxicity (myeloperoxidase, glutamine synthetase, Na+/K+ ATPase, acetylcholinesterase and tyrosine hydroxylase), was evaluated and compared with the effect produced by treatment with 20 mg/kg quercetin as a reference standard. RESULTS: Results show that pretreatment with MEA significantly mitigated or reversed BCCAO/R-induced changes in the level or activity of the evaluated biochemical markers of oxidative stress, neurochemical dysfunction and excitotoxicity compared with the BCCAO/R untreated control group (p < 0.05). The effect produced by 100 mg/kg MEA was similar to that of the reference standard, quercetin. CONCLUSION: These results revealed the neuroprotective potential of A. africana in stroke and other ischemia-related pathologies.


Assuntos
Antiaris/química , Isquemia Encefálica/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Traumatismo por Reperfusão/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Isquemia Encefálica/metabolismo , Glutationa/metabolismo , Humanos , Masculino , Malondialdeído/metabolismo , Estresse Oxidativo , Folhas de Planta/química , Ratos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Acidente Vascular Cerebral/metabolismo , Superóxido Dismutase/metabolismo
5.
BMC Res Notes ; 10(1): 167, 2017 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-28446201

RESUMO

BACKGROUND: Antiaris toxicaria has previously shown anticonvulsant activity in acute animal models of epilepsy. The aqueous extract (AAE) was further investigated for activity in kindling with pentylenetetrazole and administration of pilocarpine and kainic acid which mimic temporal lobe epilepsy in various animal species. RESULTS: ICR mice and Sprague-Dawley rats were pre-treated with AAE (200-800 mg kg-1) and convulsive episodes induced using pentylenetetrazole, pilocarpine and kainic acid. The potential of AAE to prevent or delay onset and alter duration of seizures were measured. In addition, damage to hippocampal cells was assessed in kainic acid-induced status epilepticus test. 800 mg kg-1 of the extract suppressed the kindled seizure significantly (P < 0.05) as did diazepam. AAE also produced significant effect (P < 0.01) on latency to first myoclonic jerks and on total duration of seizures. The latency to onset of wet dog shakes was increased significantly (P < 0.05) by AAE on kainic acid administration. Carbamazepine and Nifedipine (30 mg kg-1) also delayed the onset. Histopathological examination of brain sections showed no protective effect on hippocampal cells by AAE and nifedipine. Carbamazepine offered better preservation of hippocampal cells in the CA1, CA2 and CA3 regions. CONCLUSION: Antiaris toxicaria may be effective in controlling temporal lobe seizures in rodents.


Assuntos
Antiaris/química , Anticonvulsivantes/farmacologia , Epilepsia do Lobo Temporal/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Carbamazepina/farmacologia , Diazepam/farmacologia , Modelos Animais de Doenças , Esquema de Medicação , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/fisiopatologia , Hipocampo/fisiopatologia , Ácido Caínico/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos ICR , Nifedipino/farmacologia , Pentilenotetrazol/toxicidade , Pilocarpina/toxicidade , Ratos , Ratos Sprague-Dawley
6.
Fitoterapia ; 97: 71-7, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24879902

RESUMO

Five new cardiac glycosides (1-5, namely antiaroside Y-ZC) together with 19 known compounds were obtained from the bark of Antiaris toxicaria. Their chemical structures were determined by IR, HR-ESI-MS, 1D and 2D NMR (HSQC, (1)H-(1)H COSY, HMBC, ROESY). The absolute configuration of sugar unit was defined by acid hydrolysis and appropriate derivatization. Compound 1 was rare 5ß-H-10ß-H-19-nor-cardenolide, which might derive from decarboxylative derivative of 19-COOH cardenolide. The inhibitory effects of cardiac glycosides 1-11 on the viability of NIH-H460 lung cancer cells and their induction of Nur77 expression were evaluated and preliminary structure-activity relationship (SAR) was also discussed.


Assuntos
Antiaris/química , Glicosídeos Cardíacos/isolamento & purificação , Neoplasias Pulmonares/tratamento farmacológico , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Glicosídeos Cardíacos/química , Glicosídeos Cardíacos/uso terapêutico , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Neoplasias Pulmonares/metabolismo , Casca de Planta/química , Relação Estrutura-Atividade
7.
J Asian Nat Prod Res ; 16(4): 418-21, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24597720

RESUMO

A new periplogenin cardenolide, periplogulcoside (1), together with three known cardenolides, was isolated from the seeds of Antiaris toxicaria. The structure of the new compound was characterized as periplogenin-3-O-ß-D-glucopyranosyl-(1 → 4)-ß-D-glucopyranoside (1) by spectroscopic methods including 1D and 2D NMR, HR-TOF-MS, and CD spectrometry, and the known compounds were identified by comparison of their NMR and HR-TOF-MS data with those reported in the literature. Compound 1 showed significant cytotoxicity against Hela and HepG-2 cell lines.


Assuntos
Antiaris/química , Antineoplásicos Fitogênicos/isolamento & purificação , Cardenolídeos/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Cardenolídeos/química , Cardenolídeos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Células HeLa , Células Hep G2 , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Extratos Vegetais/química , Sementes/química
8.
Bioorg Med Chem ; 22(6): 1889-98, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24582402

RESUMO

Eight new cardiac glycosides/aglycones (antiaritoxiosides A-G, 1-7, and antiarotoxinin B, 8), two new coumarins (anticarins A-B, 41-42), and two new flavanones (antiarones L-K, 43-44) were isolated from trunk bark of Antiaris toxicaria together with 53 known compounds. The new structures were established by extensive analysis of spectroscopic data. Compound 1 (10-carboxy and 3α-hydroxy) and compounds 3-6 (10-hydroxy) contain unique substituents that are rarely found in cardiac glycosides. The cytotoxic effects of isolated compounds against ten human cancer cell lines, KB, KB-VIN, A549, MCF-7, U-87-MG, PC-3, 1A9, CAKI-1, HCT-9 and S-KMEL-2, were tested using the sulforhodamine B assay. Five compounds (12, 16, 20, 22, and 31) showed significant cytotoxicity against all ten cancer cell lines, with notable potency at the ng/mL level against some cell lines, which merits further development as clinical trial candidates.


Assuntos
Antiaris/química , Antineoplásicos/farmacologia , Glicosídeos Cardíacos/farmacologia , Cumarínicos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Glicosídeos Cardíacos/química , Glicosídeos Cardíacos/isolamento & purificação , Linhagem Celular Tumoral , Cumarínicos/química , Cumarínicos/isolamento & purificação , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células MCF-7 , Conformação Molecular , Casca de Planta/química , Relação Estrutura-Atividade
9.
PLoS One ; 9(3): e91094, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24663328

RESUMO

Autophagy and apoptosis are important processes that control cellular homeostasis and have been highlighted as promising targets for novel cancer therapies. Here, we identified convallatoxin (CNT), isolated from Antiaris toxicaria, as a dual inducer of autophagy and apoptosis. CNT exerts cytotoxic effects on a number of cancer and normal cell lines and induces apoptosis by increasing caspase-3 and poly ADP ribose polymerase (PARP) cleavage. Moreover, dose- and time-dependent autophagic activity was detected in CNT-treated cells, and mammalian target of rapamycin (mTOR)/p70S6K signal pathway inhibition was observed. Notably, CNT inhibits human umbilical vein endothelial cell (HUVEC) growth and exerts anti-angiogenic activity in vitro and in vivo. Collectively, these results demonstrate that the naturally occurring compound, CNT, is a novel anti-angiogenic compound via dual inducing of autophagy and apoptosis.


Assuntos
Inibidores da Angiogênese/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Neovascularização Patológica/tratamento farmacológico , Estrofantinas/farmacologia , Inibidores da Angiogênese/uso terapêutico , Antiaris/química , Linhagem Celular , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Transdução de Sinais/efeitos dos fármacos , Estrofantinas/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo
10.
J Nat Prod ; 76(9): 1771-80, 2013 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-24033101

RESUMO

Phytochemical investigation of the latex of Antiaris toxicaria resulted in the isolation of 15 new [antiarosides J-X (1-15)] and 17 known cardiac glycosides. The effects of the cardiac glycosides on apoptosis and the expression of orphan nuclear receptor Nur77 were examined in human NIH-H460 lung cancer cells. Several of the cardiac glycosides induced apoptosis in lung cancer cells, which was accompanied by induction of Nur77 protein expression. Treatment of cancer cells with the cardiac glycosides resulted in translocation of the Nur77 protein from the nucleus to the cytoplasm and subsequent targeting to mitochondria. The results show that the cardiac glycosides exert their apoptotic effect through the Nur77-dependent apoptotic pathway.


Assuntos
Antiaris/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Glicosídeos Cardíacos/isolamento & purificação , Glicosídeos Cardíacos/farmacologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Látex/química , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Glicosídeos Cardíacos/química , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Humanos , Mitocôndrias/metabolismo , Ressonância Magnética Nuclear Biomolecular , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/efeitos dos fármacos
11.
Fitoterapia ; 83(4): 660-4, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22348979

RESUMO

A new 10ß-hydroxy-19-nor-cardenolide, named toxicarioside M (1), was isolated from the trunk bark of Antiaris toxicaria (Pers.) Lesch (Moraceae), along with six known cardenolides (convallatoxin (2), convallatoxol (3), convalloside (4), 3-O-ß-D-xylopyranosylstrophanthidin (5), glucostrophanthidin (6) and strophanthidin (7)). Their structures were elucidated on the basis of HR-MS(n) analysis, spectroscopic methods (IR, UV, 1D and 2D NMR) and by comparison with data reported in the literature. The cardenolides were evaluated for their cytotoxic activity against KB, HCT-116, SF-268, MCF-7, HL-60, PC-3 and MRC-5 cell lines.


Assuntos
Antiaris/química , Antineoplásicos Fitogênicos/uso terapêutico , Cardenolídeos/uso terapêutico , Neoplasias/tratamento farmacológico , Fitoterapia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Cardenolídeos/isolamento & purificação , Cardenolídeos/farmacologia , Linhagem Celular Tumoral , Humanos , Estrutura Molecular , Casca de Planta , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Caules de Planta
12.
Asian Pac J Trop Med ; 5(2): 91-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22221748

RESUMO

OBJECTIVE: To investigate possible mechanism of toxicarioside A in HS-5 bone stromal cells. METHODS: HS-5 bone stromal cells were cultured in media supplemented with various concentrations of toxicarioside A or control DMSO (not treatment). Endoglin and TGF-ß were detected by Northern and Western blot analysis and quantified in a standard method. Downstream molecules of endoglin and TGF-ß (Smad1, Smad2 and their active phosphorylated counterparts, pSmad1 and pSmad2) were also detected and quantified by Western blot analysis. In addition, cell proliferation assay and small interfering RNA (siRNA) against endoglin were used to certificate the function of endolgin in the HS-5 cells. RESULTS: Compared with the not treated (0 µg/mL) or DMSO treated control HS-5 cells, HS-5 cells treated with toxicarioside A were found significant attenuation of endolgin and TGF-ß expression. Significant inhibition of cell proliferation was also found in the HS-5 cells treated with toxicarioside A. ALK1-related Smad1 and ALK5-related Smad2 were decreased in HS-5 cells treated with toxicarioside A. In addition, phosphorylated Smad1 (pSmad1) and Smad2 (pSmad2) were also found attenuation in toxicarioside A-treated HS-5 cells. RNA interference showed that blockage of endoglin by siRNA also decreased Smad1 and Smad2 expression in HS-5 cells. CONCLUSIONS: Our results indicate that toxicarioside A can influence bone marrow stromal HS-5's function and inhibit HS-5 cell proliferation by alteration of endoglin-related ALK1 (Smad1) and ALK5 (Smad2) signaling.


Assuntos
Antiaris , Células da Medula Óssea/efeitos dos fármacos , Cardenolídeos/farmacologia , Receptores de Superfície Celular/antagonistas & inibidores , Proteína Smad1/metabolismo , Proteína Smad2/metabolismo , Fator de Crescimento Transformador beta/antagonistas & inibidores , Antígenos CD/metabolismo , Northern Blotting , Western Blotting , Células da Medula Óssea/metabolismo , Linhagem Celular , Proliferação de Células , Endoglina , Humanos , Masculino , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Smad1/efeitos dos fármacos , Proteína Smad2/efeitos dos fármacos , Células Estromais/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismo
13.
PLoS One ; 6(6): e20714, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21674063

RESUMO

The viability of recalcitrant seeds is lost following stress from either drying or freezing. Reactive oxygen species (ROS) resulting from uncontrolled metabolic activity are likely responsible for seed sensitivity to drying. Nitric oxide (NO) and the ascorbate-glutathione cycle can be used for the detoxification of ROS, but their roles in the seed response to desiccation remain poorly understood. Here, we report that desiccation induces rapid accumulation of H(2)O(2), which blocks recalcitrant Antiaris toxicaria seed germination; however, pretreatment with NO increases the activity of antioxidant ascorbate-glutathione pathway enzymes and metabolites, diminishes H(2)O(2) production and assuages the inhibitory effects of desiccation on seed germination. Desiccation increases the protein carbonylation levels and reduces protein S-nitrosylation of these antioxidant enzymes; these effects can be reversed with NO treatment. Antioxidant protein S-nitrosylation levels can be further increased by the application of S-nitrosoglutathione reductase inhibitors, which further enhances NO-induced seed germination rates after desiccation and reduces desiccation-induced H(2)O(2) accumulation. These findings suggest that NO reinforces recalcitrant seed desiccation tolerance by regulating antioxidant enzyme activities to stabilize H(2)O(2) accumulation at an appropriate concentration. During this process, protein carbonylation and S-nitrosylation patterns are used as a specific molecular switch to control antioxidant enzyme activities.


Assuntos
Antiaris/metabolismo , Dessecação , Óxido Nítrico/farmacologia , Proteínas de Plantas/metabolismo , Carbonilação Proteica/efeitos dos fármacos , Sementes/metabolismo , Enxofre/metabolismo , Antiaris/efeitos dos fármacos , Antiaris/enzimologia , Antiaris/fisiologia , Antioxidantes/metabolismo , Germinação/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Óxido Nítrico/metabolismo , Proteínas de Plantas/química , Sementes/efeitos dos fármacos , Sementes/enzimologia , Sementes/fisiologia , Estresse Fisiológico/efeitos dos fármacos
14.
J Asian Nat Prod Res ; 13(6): 561-5, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21623521

RESUMO

A new drimane sesquiterpenoid glycoside, named 7-drimen-3ß,11-diol 3-O-ß-d-glucopyranoside, was isolated from the 95% EtOH extract of the seeds of Antiaris toxicaria (Pers.) Lesch. The chemical structure was completely elucidated using a combination of 1D and 2D NMR techniques (COSY, HMQC, HMBC, and ROESY) and HR-ESI-MS analysis. The compound showed inhibitory activities toward methicillin-resistant Staphylococcus aureus (MRSA), chronic myelogenous leukemia (K562), and human hepatoma (SMMC-7721) cell lines.


Assuntos
Antiaris/química , Antineoplásicos Fitogênicos/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Glucosídeos/isolamento & purificação , Sesquiterpenos/isolamento & purificação , Anti-Infecciosos , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Glucosídeos/química , Glucosídeos/farmacologia , Humanos , Células K562 , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos Policíclicos , Sementes/química , Sesquiterpenos/química , Sesquiterpenos/farmacologia
15.
Planta Med ; 77(15): 1730-4, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21509716

RESUMO

Bioassay-guided fractionation of the ethanolic extract from the seeds of Antiaris toxicaria led to the isolation of three new cardiac glycosides named toxicarioside J, toxicarioside K, and toxicarioside L, together with a known glucostrophalloside. The structures of the new compounds were elucidated by spectroscopic methods including HRESIMS, UV, IR, and 1D, 2D NMR techniques. The cytotoxic activities of these cardiac glycosides against human gastric (SGC-7901) and human hepatoma (SMMC-7721) cell lines were evaluated, and all of them exhibited significant cytotoxicity.


Assuntos
Antiaris/química , Antineoplásicos Fitogênicos/farmacologia , Cardenolídeos/farmacologia , Glicosídeos Cardíacos/farmacologia , Extratos Vegetais/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Bioensaio , Cardenolídeos/química , Cardenolídeos/isolamento & purificação , Glicosídeos Cardíacos/química , Glicosídeos Cardíacos/isolamento & purificação , Linhagem Celular Tumoral , Sobrevivência Celular , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Medicina Tradicional do Leste Asiático , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Plantas Medicinais/química , Sementes/química
16.
Planta Med ; 76(15): 1717-23, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20533166

RESUMO

From the methanol extract of the stem bark of the African tree Antiaris africana Engler, two new bioactive metabolites were isolated, namely, the α-amyrin derivative 1ß,11α-dihydroxy-3ß-cinnamoyl-α-amyrin (antiarol cinnamate, 1) and a cardiac glycoside, 3ß-O-(α-L-rhamnopyranosyl)-14ß-hydroperoxy-5ß-hydroxy-19-oxo-17ß-card-20(22)-enolide (africanoside, 2a), together with the known compounds ß-amyrin and its acetate, ß-sitosterol and its 3-O-ß-D-glucopyranoside, friedelin, ursolic and oleanolic acid, 19-norperiplogenin, strophanthidol, strophanthidinic acid, periplogenin (3a), 3-epiperiplogenin, strophanthidin (3b) and 3,3'-dimethoxy-4'-O-ß-D-xylopyronosyl-ellagic acid. Their structures were established on the basis of their spectroscopic data and by chemical methods, while 3a was additionally confirmed by X-ray crystal structure analysis. The aglycone moiety possessing a hydroperoxy group was found for the first time in cardenolides. Compounds 1 and 2a showed no activity against bacteria, fungi, and microalgae; however, the crude extract exhibited a high toxicity against Artemia salina and a selective antitumor activity against human tumor cell lines. Africanoside (2a) effected a concentration-dependent inhibition of tumor cell growth with a mean IC(50) value of 5.3 nM.


Assuntos
Antiaris/química , Glicosídeos Cardíacos/farmacologia , Cinamatos/farmacologia , Citostáticos/farmacologia , Triterpenos/farmacologia , Animais , Artemia/efeitos dos fármacos , Glicosídeos Cardíacos/química , Glicosídeos Cardíacos/isolamento & purificação , Linhagem Celular Tumoral , Cinamatos/química , Cinamatos/isolamento & purificação , Cristalografia por Raios X , Citostáticos/química , Citostáticos/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Ressonância Magnética Nuclear Biomolecular , Triterpenos Pentacíclicos , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Caules de Planta/química , Triterpenos/química , Triterpenos/isolamento & purificação
17.
J Integr Plant Biol ; 52(5): 434-41, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20537039

RESUMO

The relation between oxidative damage and viability loss of excised embryonic axes of Antiaris toxicaria subjected to rapid drying with silica gel at 15 degrees C was studied. Changes of survival rate, accumulation of thiobarbituric acid-reactive substances (TBARs), activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and the permeability of cell membrane that was determined as relative electrolyte leakage (REL) were measured. The half-life moisture content (MC(L50)) was 0.41 g H2O/g DW (dry weight basis). During drying, the activities of SOD, CAT and APX increased until MC(L50), and declined thereafter. The generation speed of (.)O2(-), and content of H2O2 and TBARs remained steadily or even decreased at MC levels higher than MC(L50), demonstrating a low oxidative level in these axes. There was no significant correlation between viability loss and accumulation of reactive oxygen species or lipid peroxidation within the dehydration process until MC(L50). Whereas the increase in REL from the beginning of the drying process indicated that the cell membrane was damaged. In conclusion, under rapid drying with silica gel the viability loss of excised recalcitrant A. toxicaria axes seemed to be triggered by mechanical or physical damage, rather than metabolic damage.


Assuntos
Antiaris/embriologia , Antiaris/fisiologia , Estresse Oxidativo , Sementes/fisiologia , Sobrevivência de Tecidos/fisiologia , Antiaris/enzimologia , Membrana Celular/metabolismo , Desidratação , Eletrólitos/metabolismo , Sequestradores de Radicais Livres/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos , Sementes/enzimologia , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo , Análise de Sobrevida , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Fatores de Tempo , Água
18.
J Nat Prod ; 73(7): 1214-22, 2010 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-20553004

RESUMO

An ethanolic extract of Antiaris toxicaria trunk bark showed potent in vitro cardiotonic effect on isolated guinea pig atria. Bioassay-guided fractionation of the extract led to identification of nine new cardiac glycosides (1-9, named antiarosides A-I), antiarotoxinin A (10), and 18 known compounds. Their structures were established using MS and NMR spectroscopic studies, including homonuclear and heteronuclear correlation experiments. The ability of these cardiotonic compounds to produce positive inotropic action and their safety indexes were examined in comparison with those of ouabain, a classical inhibitor of Na(+)/K(+)-ATPase. Malayoside (23) was nearly equipotent and had a similar safety index to ouabain in guinea pig atria. However, the maximal positive inotropic effect and safety index of 23 in papillary muscle were better than those of ouabain. An electrophysiological recording showed that 23 inhibited the sodium pump current in a concentration-dependent manner.


Assuntos
Antiaris/química , Glicosídeos Cardíacos/isolamento & purificação , Glicosídeos Cardíacos/farmacologia , Cardiotônicos/isolamento & purificação , Cardiotônicos/farmacologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Animais , Glicosídeos Cardíacos/química , Cardiotônicos/química , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/química , Cobaias , Átrios do Coração/efeitos dos fármacos , Ouabaína/farmacologia , Casca de Planta/química , Caules de Planta/química , Sódio/metabolismo , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores
19.
Molecules ; 14(9): 3694-9, 2009 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-19783952

RESUMO

A new nor-cardenolide, named toxicarioside H (1), was isolated from the latex of Antiaris toxicaria (Pers.) Lesch (Moraceae). Its structure was elucidated on the basis of HRFAB-MS and spectroscopic techniques (IR, UV, 1D and 2D NMR). Compound 1 showed significant cytotoxicity against K562, SGC-7901, SMMC-7721, and HeLa cell lines in vitro by MTT method.


Assuntos
Antiaris/química , Cardenolídeos/isolamento & purificação , Cardenolídeos/farmacologia , Glicosídeos Cardíacos/isolamento & purificação , Glicosídeos Cardíacos/farmacologia , Látex/química , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância Magnética
20.
J Integr Plant Biol ; 51(7): 646-53, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19566643

RESUMO

Long-term preservation of recalcitrant seeds is very difficult because the physiological basis on their desiccation sensitivity is poorly understood. Survival of Antiaris toxicaria axes rapidly decreased and that of immature maize embryos very slowly decreased with dehydration. To understand their different responses to dehydration, we examined the changes in mitochondria activity during dehydration. Although activities of cytochrome (Cyt) c oxidase and malate dehydrogenase of the A. toxicaria axis and maize embryo mitochondria decreased with dehydration, the parameters of maize embryo mitochondria were much higher than those of A. toxicaria, showing that the damage was more severe for the A. toxicaria axis mitochondria than for those of maize embryo. The state I and III respiration of the A. toxicaria axis mitochondria were higher than those of maize embryo, the former rapidly decreased, and the latter slowly decreased with dehydration. The proportion of Cyt c pathway to state III respiration for the A. toxicaria axis mitochondria was low and rapidly decreased with dehydration, and the proportion of alternative oxidase pathway was high and slightly increased with dehydration. In contrast, the proportion of Cyt c pathway for maize embryo mitochondria was high, and that of alternative oxidase pathway was low. Both pathways decreased slowly with dehydration.


Assuntos
Antiaris/embriologia , Mitocôndrias/metabolismo , Sementes/metabolismo , Zea mays/embriologia , Antiaris/efeitos dos fármacos , Respiração Celular/efeitos dos fármacos , Desidratação , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Malato Desidrogenase/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Cianeto de Potássio/farmacologia , Salicilamidas/farmacologia , Sementes/efeitos dos fármacos , Água/metabolismo , Zea mays/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...