Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
1.
Article in English | WPRIM | ID: wpr-888778

ABSTRACT

Two new lignan glucosides, tinsinlignans A and B (1 and 2), two new oxyneolignans, tinsinlignans C and D (3 and 4), along with one known analogue (5), were isolated from the stems of Tinospora sinensis. The structures of the new compounds were elucidated based on analysis of spectroscopic data, and the absolute configuration of 1 was determined through electronic circular dichroism (ECD) calculation based on the time-dependent density functional theory (TD-DFT). Compounds 1-4 were evaluated for their inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in murine RAW264.7 macrophage cells and compounds 1 and 2 exhibited moderate inhibitory activities with IC


Subject(s)
Animals , Glucosides/pharmacology , Lignans/pharmacology , Lipopolysaccharides , Mice , Molecular Structure , Nitric Oxide , Phytochemicals/pharmacology , Tinospora/chemistry
2.
Chinese Journal of Biotechnology ; (12): 580-592, 2021.
Article in Chinese | WPRIM | ID: wpr-878583

ABSTRACT

A novel β-glucosidase BglD2 with glucose and ethanol tolerant properties was screened and cloned from the deep-sea bacterium Bacillus sp. D1. The application potential of BglD2 toward polydatin-hydrolyzing was also evaluated. BglD2 exhibited the maximal β-glucosidase activity at 45 °C and pH 6.5. BglD2 maintained approximately 50% of its origin activity after incubation at 30 °C and pH 6.5 for 20 h. BglD2 could hydrolyze a variety of substrates containing β (1→3), β (1→4), and β (1→6) bonds. The activity of β-glucosidase was enhanced to 2.0 fold and 2.3 fold by 100 mmol/L glucose and 150 mmol/L xylose, respectively. BglD2 possessed ethanol-stimulated and -tolerant properties. At 30 °C, the activity of BglD2 enhanced to 1.2 fold in the presence of 10% ethanol and even remained 60% in 25% ethanol. BglD2 could hydrolyze polydatin to produce resveratrol. At 35 °C, BglD2 hydrolyzed 86% polydatin after incubation for 2 h. Thus, BglD2 possessed glucose and ethanol tolerant properties and can be used as the potential candidate of catalyst for the production of resveratrol from polydatin.


Subject(s)
Enzyme Stability , Glucose , Glucosides/pharmacology , Hydrogen-Ion Concentration , Stilbenes/pharmacology , Substrate Specificity , Temperature , Xylose , beta-Glucosidase/genetics
3.
Braz. j. med. biol. res ; 52(12): e8834, 2019. graf
Article in English | LILACS | ID: biblio-1055472

ABSTRACT

Polydatin (PD), a monocrystalline polyphenolic drug mainly found in the roots of Polygonum cuspidatum, has various pharmacological activities. Long non-coding RNAs (lncRNA) DiGeorge syndrome critical region gene 5 (DGCR5) was found to participate in the suppression of multiple cancers. Here, we proposed to study the effect of PD on myocardial infarction (MI) by inducing DGCR5. CCK-8 assay was performed to detect the viability of H9c2 cells. Flow cytometry was utilized to test apoptosis of H9c2 cells. These results determined the optimal concentration and effect time of hypoxia as well as PD. Si-DGCR5 was transfected into cells and the expression level was determined by qRT-PCR. Western blot was utilized to evaluate the expression of apoptosis-related proteins, Bcl-2, Bax, and cleaved-caspase-3, as well as autophagy-associated proteins including Beclin-1, p62, and LC3-II/LC3-I. As a result, PD efficiently attenuated hypoxia-induced apoptosis and autophagy in H9c2 cells. The expression of DGCR5 was down-regulated by hypoxia and up-regulated by PD. Besides, knocking-down the expression of DGCR5 inhibited the protection of PD in H9c2 cells. In addition, PD up-regulated the accumulation of DGCR5, DGCR5 decreased the expression of Bcl-2 and p62, raised the expression of Bax and cleaved-caspase-3, and the proportion of LC3-II/LC3-I. PD stimulated the PI3K/AKT/mTOR and MEK/ERK signaling pathways via up-regulating the expression of DGCR5. Our data demonstrated that PD reduced cell apoptosis and autophagy induced by hypoxia in cardiomyocytes. Moreover, PD activated PI3K/AKT/mTOR and MEK/ERK signaling pathways by up-regulating the expression of DGCR5.


Subject(s)
Animals , Rats , Stilbenes/pharmacology , Cell Hypoxia/drug effects , Apoptosis/drug effects , Myocytes, Cardiac/drug effects , Cell Proliferation/drug effects , RNA, Long Noncoding/drug effects , Glucosides/pharmacology , Signal Transduction , Up-Regulation/drug effects , Cell Line , Cytoprotection , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology
4.
Braz. j. med. biol. res ; 51(10): e7439, 2018. graf
Article in English | LILACS | ID: biblio-951707

ABSTRACT

Nuclear factor erythroid-related factor 2 (Nrf2) has been implicated in several detoxifying and antioxidant defense processes. Nrf2-mediated heme oxygenase-1 (HO-1) expression was demonstrated to play a key role against oxidative stress. Gastrodin (GSTD) is a well-known active compound isolated from the roots of Rhizoma gastrodiae, a plant used in ancient Chinese traditional medicine. The aim of this work was to investigate whether GSTD could alleviate H2O2-induced oxidative stress in mouse liver sinusoidal endothelial cells (LSECs). In LSECs exposed to 1 mM H2O2, treatment with GSTD (1, 10, or 50 µM) resulted in higher cell viability than the untreated control. Treated cells maintained a higher Bcl2/Bax ratio and suppressed caspase-9 expression compared with untreated cells, reducing cell apoptosis. GSTD was protective for H2O2-induced oxidative injury by reducing the generation of intracellular reactive oxygen species and malondialdehyde. HO-1 and Nrf2 expressions were synergistically upregulated by GSTD. Inhibition of HO-1 by 10 µM zinc protoporphyrin resulted in less protective effects on cell viability and malondialdehyde reduction by GSTD treatment in H2O2-exposed LSECs. Additionally, phosphorylated p38 in LSECs exposed to H2O2 was elevated by GSTD. Inhibition of p38 phosphorylation by SB203580 did not induce Nrf2 and HO-1 expression after 1 or 10 µM GSTD treatment and the protective effect on cell viability and malondialdehyde reduction in H2O2-exposed LSECs was reduced. The data conclusively demonstrated that GSTD-induced HO-1 and Nrf2 expression is involved in protection of LSECs from H2O2-induced oxidative injury, which may be regulated by p38 phosphorylation.


Subject(s)
Animals , Rabbits , Benzyl Alcohols/pharmacology , Endothelial Cells/drug effects , p38 Mitogen-Activated Protein Kinases/metabolism , Heme Oxygenase-1/metabolism , Glucosides/pharmacology , Hydrogen Peroxide/pharmacology , Up-Regulation/drug effects , Cell Survival/drug effects , Apoptosis/drug effects , Liver/cytology , Liver/drug effects , Malondialdehyde/metabolism , Models, Theoretical
5.
Braz. j. med. biol. res ; 51(4): e6867, 2018. graf
Article in English | LILACS | ID: biblio-889068

ABSTRACT

Polydatin, a small molecule from Polygonum cuspidatum, has many biological functions, particularly anti-cancer effects. However, the anti-cancer effects of polydatin in hepatocellular carcinoma (HCC) have not been examined yet. In the present study, MTT assay, BrdU assay, transwell invasion assay, and wound healing assay were performed to determine cell proliferation, invasion and migration. Flow cytometry and TUNEL assay were used to measure cell apoptosis. Quantitative real-time PCR and western blotting assays were used to determine mRNA and protein expression levels. Xenograft experiment was performed to determine the in vivo anti-tumor effect of polydatin. Immunostaining was performed to analyze the expression of caspase-3 and Ki-67. Our results showed that polydatin inhibited cell proliferation in a concentration-dependent and time-dependent manner in the HCC cell lines. Polydatin also induced cell apoptosis in a concentration-dependent manner possibly via increasing the caspase-3 activity, and up-regulating the protein expression of caspase-3, caspase-9, Bax, and down-regulating the protein expression of Bcl-2. In addition, polydatin treatment had an inhibitory effect on cell proliferation, invasion and migration in HCC cell lines. Polydatin treatment also suppressed the Wnt/beta-catenin signaling activities in HCC cells. Polydatin treatment significantly reduced tumor growth in nude mice inoculated with HepG2 cells, suppressed the expression of Ki-67, and increased caspase-3 expression and TUNEL activity. Our data indicated the important role of polydatin for the suppression of HCC progression.


Subject(s)
Animals , Male , Mice , Stilbenes/pharmacology , Cell Movement/drug effects , Apoptosis/drug effects , Carcinoma, Hepatocellular/drug therapy , Cell Proliferation/drug effects , Glucosides/pharmacology , Liver Neoplasms, Experimental/drug therapy , Drugs, Chinese Herbal , Blotting, Western , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Real-Time Polymerase Chain Reaction , Flow Cytometry , Liver Neoplasms, Experimental/pathology , Mice, Inbred BALB C , Mice, Nude , Neoplasm Invasiveness
6.
Bol. latinoam. Caribe plantas med. aromát ; 15(5): 288-300, Sept. 2016. ilus
Article in English | LILACS | ID: biblio-907546

ABSTRACT

Ultraviolet radiation (UVR) is involved in both sunburn and the development of skin cancer, which has a high incidence worldwide. Strategies to reduce these effects include the use of photoprotective substances. The aim of this work was to investigate the photoprotective effect of verbascoside isolated from the methanolic extract of Buddleja cordata (BCME) in SKH-1 mice exposed to acute and chronic UV-B radiation. The mouse dorsal area was evaluated macroscopically and microscopically for diagnosis; verbascoside penetration into mouse skin was investigated in vivo by the tape stripping method. After acute UV-B exposure, 100 percent of irradiated mice that had been protected with verbascoside showed no signs of sunburn or of inflammatory processes. After chronic exposure, 100 percent of unprotected mice showed skin carcinomas; in contrast, in mice topically treated with either BCME or verbascoside, the presence of lesions was decreased by 90 percent. These results prove that verbascoside penetrates through the skin of mice and suggest that verbascoside and BCME may potentially prevent photodamage on mice’s skin after acute and chronic UVR exposure.


La radiación ultravioleta (RUV) provoca quemaduras solares y el desarrollo de cáncer de piel. El objetivo de este trabajo fue investigar el efecto fotoprotector del verbascósido obtenido del extracto metanólico de Buddleja cordata (EMBC) en ratones SKH-1 expuestos a RUV-B de manera aguda y crónica. El diagnóstico histológico se llevó a cabo en la piel de la zona dorsal de los ratones. La penetración del verbascósido fue cuantificada mediante la técnica de la cinta adhesiva. En el experimento agudo, el 100 por ciento de los ratones protegidos con verbascósido no evidenciaron signos de quemadura ni procesos inflamatorios. En el experimento crónico los ratones sin protección e irradiados presentaron carcinomas cutáneos. En contraste en los ratones protegidos con EMBC o verbascósido las lesiones disminuyeron un 90 por ciento en ambos grupos. El verbascósido penetró en la piel del ratón. Los resultados sugieren que el EMBC y el verbascósido previenen el fotodaño en la piel de ratones expuestos de forma aguda o crónica a la RUV.


Subject(s)
Animals , Mice , Buddleja/chemistry , Phenols/pharmacology , Plant Extracts/pharmacology , Skin , Skin/radiation effects , Erythema/prevention & control , Glucosides/pharmacology , Mice, Hairless , Skin/pathology , Sunburn/prevention & control , Ultraviolet Rays/adverse effects
7.
Indian J Exp Biol ; 2015 Mar; 53(3): 143-151
Article in English | IMSEAR | ID: sea-158399

ABSTRACT

In animals, long-term feeding with peanut (Arachis hypogaea) seed coats causes hypertrophy and hyperplasia of the thyroid gland. However, to date there have been no detailed studies. Here, we explored the thyroidal effects of dietary peanut seed coats (PSC) in rats. The PSC has high levels of pro-goitrogenic substances including phenolic and other cyanogenic constituents. The PSC was mixed with a standard diet and fed to rats for 30 and 60 days, respectively. Animals fed with the PSC-supplemented diet showed a significant increase in urinary excretion of thiocyanate and iodine, thyroid enlargement, and hypertrophy and/or hyperplasia of thyroid follicles. In addition, there was inhibition of thyroid peroxidase (TPO) activity, 5’-deiodinase-I (DIO1) activity, and (Na+-K+)-ATPase activity in the experimental groups of rats as compared to controls. Furthermore, the PSC fed animals exhibited decreased serum circulating total T4 and T3 levels, severe in the group treated for longer duration. These data indicate that PSC could be a novel disruptor of thyroid function, due to synergistic actions of phenolic as well as cyanogenic constituents.


Subject(s)
Animal Feed/adverse effects , Animals , Antithyroid Agents/isolation & purification , Antithyroid Agents/toxicity , Arachis/chemistry , Drug Synergism , Glucosides/analysis , Glucosides/pharmacology , Glucosides/toxicity , Hyperplasia , Hypertrophy , Hyperthyroidism/blood , Hyperthyroidism/chemically induced , Iodide Peroxidase/antagonists & inhibitors , Iodine/urine , Male , Nitriles/analysis , Nitriles/pharmacology , Nitriles/toxicity , Ovule/chemistry , Polyphenols/analysis , Polyphenols/pharmacology , Polyphenols/toxicity , Rats , Rats, Wistar , Sodium-Potassium-Exchanging ATPase/antagonists & inhibitors , Thiocyanates/urine , Thyroid Gland/drug effects , Thyroid Gland/enzymology , Thyroid Gland/pathology , Thyroid Hormones/blood
8.
Bol. latinoam. Caribe plantas med. aromát ; 13(2): 189-197, mar. 2014. ilus
Article in English | LILACS | ID: lil-767362

ABSTRACT

The estrous cycle disruptor effect of an ethanolic extract (EMATst) from Buddleja globosa leaves and standardized in its main component (verbascoside) was determined in rats after the subcutaneous administration of EMATst. Binding of EMATst and verbascoside to the estrogen receptor (ER) of EMATst and verbacoside was also measuredestablished. EMATst produced a significant alteration inof the estrous cycle only at the highest dose (10-5 M), which could be attributed to an antiestrogenic effect. The Bbinding of EMATst and verbascoside to the ER was competitive and occurred in concentrations 1000 times greater than that of 17beta-estradiol.


El efecto disruptor del ciclo estral de un extracto etanólico (EMATst) obtenido a partir de las hojas de Buddleja globosa y estandarizado en su componente mayoritario (verbascósido) fue determinado en ratas después de la administración subcutánea de EMATst. Se estableció además la unión al receptor estrogénico (RE) tanto de EMATst como de verbascósido. EMATst sólo a la dosis más alta (10-5M) produjo una alteración significativa del ciclo estral, lo que podría atribuirse a un efecto antiestrogénico. La unión al RE de EMATst y verbascósido se produjo a concentraciones 1000 veces mayor que el 17beta-estradiol y de forma competitiva.


Subject(s)
Animals , Rats , Buddleja/chemistry , Estrous Cycle , Plant Extracts/pharmacology , Phenols/pharmacology , Glucosides/pharmacology , Ethanol , Plant Leaves/chemistry , Rats, Sprague-Dawley , Receptors, Estrogen
9.
Biol. Res ; 47: 1-11, 2014. graf, tab
Article in English | LILACS | ID: biblio-950746

ABSTRACT

BACKGROUND: Accumulating evidence indicates that reactive oxygen species (ROS) are an important etiological factor for the induction of dermal papilla cell senescence and hair loss, which is also known alopecia. Arctiin is an active lignin isolated from Arctium lappa and has anti-inflammation, anti-microbial, and anti-carcinogenic effects. In the present study, we found that arctiin exerts anti-oxidative effects on human hair dermal papilla cells (HHDPCs). RESULTS: To better understand the mechanism, we analyzed the level of hydrogen peroxide (H2O2)-induced cytotoxicity, cell death, ROS production and senescence after arctiin pretreatment of HHDPCs. The results showed that arctiin pretreatment significantly inhibited the H2O2-induced reduction in cell viability. Moreover, H2O2-induced sub-G1 phase accumulation and G2 cell cycle arrest were also downregulated by arctiin pretreatment. Interestingly, the increase in intracellular ROS mediated by H2O2 was drastically decreased in HHDPCs cultured in the presence of arctiin. This effect was confirmed by senescence associated-beta galactosidase (SA-ß-gal) assay results; we found that arctiin pretreatment impaired H2O2-induced senescence in HHDPCs. Using microRNA (miRNA) microarray and bioinformatic analysis, we showed that this anti-oxidative effect of arctiin in HHDPCs was related with mitogen-activated protein kinase (MAPK) and Wnt signaling pathways. CONCLUSIONS: Taken together, our data suggest that arctiin has a protective effect on ROS-induced cell dysfunction in HHDPCs and may therefore be useful for alopecia prevention and treatment strategies.


Subject(s)
Humans , Aging/metabolism , Reactive Oxygen Species/antagonists & inhibitors , Hair Follicle/drug effects , MicroRNAs/metabolism , Furans/pharmacology , Glucosides/pharmacology , Aging/drug effects , Down-Regulation/drug effects , Up-Regulation/drug effects , Cell Line , Cell Survival/drug effects , Cell Death/drug effects , beta-Galactosidase/analysis , Hair Follicle/cytology , Hair Follicle/metabolism , Dermis/cytology , Dermis/drug effects , Dermis/metabolism , Oligonucleotide Array Sequence Analysis , MicroRNAs/drug effects , Cell Cycle Checkpoints/drug effects , Hydrogen Peroxide/pharmacology
10.
Biol. Res ; 45(4): 403-410, 2012. ilus
Article in English | LILACS | ID: lil-668693

ABSTRACT

Objectives: Gastrodia elata (GE) Blume (Orchidaceae) has been previously known for its therapeutic benefits against neurodegenerative diseases. Microglial activation and death have been implicated in the pathogenesis of a variety of neurodegenerative diseases, including Alzheimer's disease. In this study, GE and its pure components, gastrodin and 4-hydroxybenzyl alcohol (4HBA), were applied to β-amyloid-induced BV2 mouse microglial cells. Materials and Methods Cell viability was assessed by the MTT assay and Western blotting was also performed. Results: β-amyloid-induced cell death was shown to be induced time- and dose-dependently. To examine the cell death mechanism, we confirmed the involvement of ER stress signaling. C/EBP homologous protein (CHOP), a pro-apoptotic ER stress protein, was expressed at high levels but glucose-regulated protein 78 (GRP78), an anti-apoptotic ER stress protein with chaperone activity, was only slightly affected by treatment with β-amyloid. However, pretreatment with GE and its components inhibited the expression of CHOP but increased that of GRP78 in β-amyloid-treated cells. This study also showed that a single treatment with GE extracts, gastrodin, or 4HBA induced the expression of GRP78, a marker for enhanced protein folding machinery, suggesting a protective mechanism for GE against β-amyloid. Conclusions: This study reveals the protective effects of GE against β-amyloid-induced cell death, possibly through the enhancement of protein folding machinery of a representative protein, GRP78, and the regulation of CHOP in BV2 mouse microglial cells.


Subject(s)
Animals , Mice , Amyloid/pharmacology , Benzyl Alcohols/pharmacology , Cell Death/drug effects , Cell Survival/drug effects , Gastrodia/chemistry , Glucosides/pharmacology , Microglia/drug effects , Benzyl Alcohols/isolation & purification , Glucosides/isolation & purification
11.
Pakistan Journal of Pharmaceutical Sciences. 2010; 23 (2): 182-187
in English | IMEMR | ID: emr-98352

ABSTRACT

Preliminary pharmacological study was conducted for the pterocarpans macckian [Mac] and trifolirhizin [Trif]. The two compounds isolated from Ononis vaginalis were tested for their hepatoprotective effects against CCU[4] induced hepatotoxicity in rats. Activity was accessed by measuring liver enzymes and NP-SH groups. Estrogenic activity was expressed as increase in uterine weight of young female rats. Rat paw edema as a model of acute inflammation induced in Wistar rats using carragenan was used to evaluate the anti-inflammatory activity. Percentage inhibition of the aggregation induced by adenosine diphosphate [ADP] to platelets-rich plasma [PRP] obtained from rats was used as measure for antiplatelet aggregation effect. The aglycone Mac was only more active than the glycoside Trif in the anti-inflammatory assay. It resulted in 65.7% reduction in carregeenan induced rat paw edema compares with 79.8% reduction by indomethacin at the same molar concentration. The activity of Trif was about half of that of silymarin in reducing the elevated levels of liver enzymes at the same molar concentration. About 10 fold molar concentration of Trif produced about half fold increase in uterine weight produced by 17 beta estradiol


Subject(s)
Animals , Male , Female , Plant Roots/chemistry , Plant Extracts/pharmacology , Drug Evaluation, Preclinical/methods , Fabaceae , Glucosides/pharmacology , Heterocyclic Compounds, 4 or More Rings/pharmacology , Rats, Wistar
12.
Rev. biol. trop ; 44(2A): 353-9, ago. 1996. ilus, tab
Article in Spanish | LILACS | ID: lil-218365

ABSTRACT

After intraperitoneal administration of gradual aqueous doses obtained from Stachytarpheta jamaicensis leaves, the following effects were observed in rats: a reduction of motor activity and the alarm reaction, ataxia, sedation, analgesia, anesthesia, ptosis, piloerection, head tremors and a significant reduction of body temperature of about 8.4 degrees C. Robichaud's sign was present, probably due to some muscular relaxation. There were appreciable changes on respiration, with increment on amplitudes and reduction on the frequency, followed by apnea and the death of the animals, probably due to asphysia. Iridoid polamiide and the phenylpropanoid glycoside, verbascoside, were identified from the same extracts. Both metabolites have been indicated with potential pharmaceuticals properties in accord with ethnobotanical value Tributed to this plant


Subject(s)
Animals , Rats , Analgesics/pharmacology , Anesthetics/pharmacology , Glycosides/pharmacology , Glycosides/chemistry , Glucosides/chemistry , Glucosides/pharmacology , Motor Activity/drug effects , Plant Extracts/pharmacology , Rosales/chemistry , Plant Extracts , Rats, Wistar
13.
Ciênc. cult. (Säo Paulo) ; 43(4): 310-2, July-Aug. 1991. tab
Article in English | LILACS | ID: lil-113795

ABSTRACT

Diante das importantes funçöes celulares como a endocitose, a digestäo e a desintoxicaçäo, exercidas pelos diferentes componentes do compartimento lisossômico, decidimos estudar os efeitos in vivo do esteviosídeo sobre a atividade lisossômica. Näo foram observadas mudanças estatisticamente significantes na estabilidade das membranas lisossômicas do rim e do fígado, em camundongos tratados com 50mg/Kg peso corporal/dia. Na dose de 100mg/Kg/dia foi observado um pequeno efeito labilizador nos lisossomos hepáticos, mas näo sobre os renais


Subject(s)
Animals , Male , Female , Mice , Rats , Glucosides/pharmacology , Lysosomes/drug effects , Terpenes/pharmacology , Liver/cytology , Liver , Kidney/cytology , Kidney/drug effects , Random Allocation
14.
Braz. j. med. biol. res ; 24(8): 767-71, 1991. ilus, tab
Article in English | LILACS | ID: lil-102061

ABSTRACT

The effect of stevioside, an inhibitor of long-chain fatty acid transport, on ketogenesis and on [14C]CO2 production from [1-14C] palmitate (100-300µM) was investigated in the isolated and hemoglobin-free perfused rat liver. Stevioside (2.5mM), a sweet glycoside found in Stevia rebaudiana leaves, inhibited both parameters, but had a lower effection on [14C]CO2 production. At 300µM palmitate and 150 µM albumin, for example, ketogenesis was inhibited by 66.3%, whereas no significant inhibition of [14C]CO2 was demonstrable. These results were interpreted to reflect 1) different degress of saturation of the citric acid cycle and the ketogenic patheay and 2) changes in the redox state of the mitochondrial NAD+-NADH couple which may also occur upon stevioside infusion


Subject(s)
Animals , Rats , Ketone Bodies/biosynthesis , Carbon Dioxide/metabolism , Glucosides/pharmacology , Palmitates/antagonists & inhibitors , Cell Membrane Permeability , Oxygen Consumption , Liver/metabolism
15.
Rev. UNIMAR ; 7(1): 85-95, out. 1985.
Article in Portuguese | LILACS | ID: lil-29624

ABSTRACT

O efeito do steviol e do steviosídeo sobre a liberaçäo de proteínas no fígado de rato perfundido isoladamente foi investigado. O steviol induz considerável aumento na liberaçäo de proteínas quando infundido numa concentraçäo igual a 0,5 mM. Estas proteínas têm origem intracelular, conforme indicado pelas medidas de enzimas de natureza citosólica e mitocondrial (L-lactato desidrogenase e fumarase). O steviosídeo näo provoca nenhum aumento na liberaçäo de proteínas quando infundido numa concentraçäo igual a 1 mM. O efeito do steviol é reversível. A causa da liberaçäo de proteínas pode estar relacionada com a açäo do steviol sobre a cadeia respiratória


Subject(s)
Rats , Animals , Male , Liver/metabolism , Glucosides/pharmacology , Proteins/metabolism , Perfusion
16.
Rev. UNIMAR ; 7(1): 97-121, out. 1985. tab
Article in Portuguese | LILACS | ID: lil-29628

ABSTRACT

Foram estudados os efeitos do steviol e do isosteviol sobre a respiraçäo e sobre o metabolismo glicídico em fígado de rato perfundido isoladamente. Foram obtidos os seguintes resultados: 1) O isosteviol e o steviol reduzem as taxas de consumo de oxigênio do fígado. 2) A infusäo de steviol e isosteviol em fígado de rato alimentado normalmente leva a aumento nas taxas de produçäo de L-lactato mais piruvato e na liberaçäo de glucose, indicando ativaçöes na glicólise e na glicogenólise. 3) A produçäo de L-lactato mais piruvato, quando a glucose ou a frutose säo infundidas em fígado de rato em jejum de 24 horas, é ativada por isosteviol até concentraçöes próximas a 0,5 mM. Concentraçöes maiores provocam inibiçäo. 4) A gluconeogênese a partir de frutose e de glicerol é inibida pelo isosteviol e pelo steviol, havendo uma relaçäo linear entre o grau de inibiçäo da síntese de glucose e o grau de inibiçäo da respiraçäo. Os dados sugerem que o aumento nas taxas de produçäo de L-lactato mais piruvato a partir de glicogênio e de substratos exógenos (glucose, frutose e glicerol) säo efeitos secundários que têm como causa a inibiçäo da respiraçäo. A inibiçäo da gluconeogênese seria conseqüência do descréscimo da produçäo da ATP, a qual é conseqüência da açäo do isosteviol e do steviol sobre a fosforilaçäo oxidativa. Há diversas evidências metabólicas de uma inibiçäo do transporte de glucose através da membrana plasmática. Os efeitos observados sobre o metabolismo glicídio acrescentam dados consistentes com a açäo hipoglicemiante detectada por alguns autores no tocante aos produtos naturais da Stevia rebaudiana


Subject(s)
Rats , Animals , Male , Carbohydrates/metabolism , Liver/metabolism , Glucosides/pharmacology , Perfusion
18.
Indian J Physiol Pharmacol ; 1975 Oct-Dec; 19(4): 218-20
Article in English | IMSEAR | ID: sea-107226

ABSTRACT

A comparative study of the hypoglycaemic action of the ethabolic extract of the bark of Ficus bengalensis and a glucoside isolated from it has been made with tolbutamide, both in normal and alloxan diabetic rabbits. The glucoside is more active than the crude extract and it is half as potent as tolbutamide.


Subject(s)
Animals , Blood Glucose/analysis , Depression, Chemical , Diabetes Mellitus, Experimental/blood , Glucosides/pharmacology , Glycosides/pharmacology , Hypoglycemic Agents , Male , Plant Extracts/pharmacology , Rabbits , Tolbutamide/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL