ABSTRACT
Objective: To screen active components and main target molecules from Sorbus tianschanica for treatment of myocardial ischemia/reperfusion by network pharmacology methods, and verify its protective effects and mechanism of flavonoids in S. tianschanica (FST). Methods: The compounds from S. tianschanica with protective effects against myocardial ischemia reperfusion injury (MIRI) were screened and the compound-target-disease network and protein interaction network were constructed, and the key targets were located through TCMSP database. Langendorff-reperfusion rat isolated-hearts were prepared to induce MIRI. The high dose (1.5 mg/L), low dose (0.5 mg/L) of FST, and 4'-chlorodiazepam (CDZ, 1 μmol/L) were administrated for pretreatment respectively. Hemodynamic index, infarct size of myocardial tissue, and the pathological changes of myocardium were analyzed. Moreover, superoxide dismutase (SOD), malondialdehyde (MDA), glutathione/ oxidized glutathione (GSH/GSSG), catalase (CAT), total antioxidant capacity (T-AOC) and the opening degree of mPTP were determined. Results: The active components screened from S. tianschanica by network pharmacology in treatment of myocardial ischemia reperfusion were flavonoids; The core target was TSPO, which was closely related to mitochondrial permeability transition pore mPTP. Each treatment group significantly enhanced the cardiac function index, reduced infarct size of myocardial tissue, increased the activity of SOD and CAT (P < 0.01), increased GSH/GSSG and T-AOC of myocardial tissue (P < 0.01), and inhibited the opening of mPTP. High dose (1.5 mg/L) had the strongest effect by contrast. Conclusion: Flavonoids of S. tianschanica can enhance the function of myocardial relaxation and contraction, reduce the area of myocardial infarction and the oxidative stress injury of myocardial tissue; It can inhibit the opening of mPTP by the main target TSPO to reduce the mitochondrial swelling of myocardial cells.
ABSTRACT
Objective: To evaluate the antioxidant and radical scavenging activities of Solanum anguivi fruit (SAG) and its possible effect on mitochondrial permeability transition pore as well as mitochondrial membrane potential (ΔΨm) isolated from rat liver. Methods: Antioxidant activity of SAG was assayed by using 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power, iron chelation and ability to inhibit lipid peroxidation in both liver and brain homogenate of rats. Also, the effect of SAG on mitochondrial membrane potential and mitochondrial swelling were determined. Identification and quantification of bioactive polyphenolics was done by HPLC-DAD. Results: SAG exhibited potent and concentration dependent free radical-scavenging activity (IC50/DPPH=275.03±7.8 μg/mL). Reductive and iron chelation abilities also increase with increase in SAG concentration. SAG also inhibited peroxidation of cerebral and hepatic lipids subjected to iron oxidative assault. SAG protected against Ca2+ (110 μmol/L)-induced mitochondrial swelling and maintained theΔΨm. HPLC analysis revealed the presence of gallic acid [(17.54±0.04) mg/g], chlorogenic acid (21.90±0.02 mg/g), caffeic acid (16.64±0.01 mg/g), rutin [(14.71±0.03) mg/g] and quercetin [(7.39±0.05) mg/g]. Conclusions:These effects could be attributed to the bioactive polyphenolic compounds present in the extract. Our results suggest that SAG extract is a potential source of natural antioxidants that may be used not only in pharmaceutical and food industry but also in the treatment of diseases associated with oxidative stress.
ABSTRACT
The aim of this study was to determine whether eupafolin and hispidulin, flavones extracted from Eupatorium littorale Cabrera, Asteraceae, have the ability to change properties of biological membranes and promote cytotoxic effects. Eupafolin (50-200 µM) decreased approximately 30 percent the rate and total amplitude of valinomycin induced swelling and 60-100 percent the energy-dependent mitochondrial swelling. Moreover, eupafolin (200 µM) reduced 35 percent the mitochondrial permeability transition, and hispidulin did not change this parameter in any of the doses tested. The evaluation of phase transition of DMPC liposomes with the probe DPH demonstrated that hispidulin and eupafolin affect gel and fluid phase. With mitochondrial membrane as model, hispidulin increased the polarization of fluorescence when used DPH-PA probe. Eupafolin and hispidulin (100 µM) promoted a reduction of 40 percent in cellular viability of HeLa cells in 24 h. Our results suggest that eupafolin and hispidulin have cytotoxic effects that can be explained, in part, by alterations promoted on biological membranes properties and mitochondrial bioenergetics.
O objetivo deste estudo foi avaliar se eupafolina e hispidulina, flavonas extraídas do Eupatorium littorale Cabrera, Asteraceae, possuíam a capacidade de alterar propriedades das membranas biológicas e promover efeitos citotóxicos. Eupafolina (50-200 µM) reduziu em aproximadamente 30 por cento a velocidade e amplitude do inchamento mitocondrial induzido por valinomicina e 60-100 por cento o inchamento mitocondrial dependente de substrato. Além disso, eupafolina na dose de 200 µM reduziu a transição de permeabilidade mitocondrial em 35 por cento entretanto, a hispidulina não alterou este parâmetro em todas as doses testadas. A avaliação da transição de fase dos lipossomas de DMPC com a sonda DPH demonstrou que ambas as flavonas afetam a fase gel e fluida. Quando lipossomas de membranas mitocondriais e a sonda DPH-PA foram utilizados, houve aumento da polarização de fluorescência promovido pela hispidulina. Eupafolina e hispidulina, na dose de 100 µM, promoveram 40 por cento de redução da viabilidade de células HeLa em 24 h. Nossos resultados sugerem que eupafolina e hispidulina têm efeitos citotóxicos que podem ser explicados em parte pelas alterações promovidas por estas flavonas sobre propriedades de membranas biológicas e sobre a bioenergética mitocondrial.
ABSTRACT
Cerebral ischemia has been extensively studied in order to obtain effective therapeutic measures that might minimize its effects, since a large number of clinical or surgical patients frequently suffer irreversible consequences of this condition. The choice of a satisfactory experimental model to be used in research on neuroprotective agents has been the basis of these studies. In the present investigation, the cat was chosen as an experimental model of ischemia and the condition was evaluated on the basis of two parameters, i.e., mitochondrial respiration and swelling. The animals used in the experiment (N = 32) were divided into four groups; three groups of 10 animals each were submitted to progressively increasing periods of ischemia (15, 30 and 60 minutes), and the last group (N = 2) was not submitted to ischemia. Clear changes in the curves of energized mitochondrial swelling were observed in the animals submitted to 60 minutes of ischemia when the ischemic side was compared to the control, and this occurrence was even clearer when the antibiotic alameticin was added during the laboratory assays of swelling. It is possible to find these conclusions: swelling is an indicator of mitochondrial differentiation between tissues; brain mitochondrion when exposed to effects of alameticin presents a different sensibility if is comparison to other tissues; brain mitochondria submitted to ischemia during 60 minutes became more sensibility to alameticin; and finally, brain mitochondria have an extremely fast installation of reversion swelling.
A isquemia cerebral tem sido largamente estudada com intuito de se obter medidas terapêuticas eficazes que minimizem seus efeitos, visto que uma grande quantidade de pacientes, clínicos ou cirúrgicos, apresentam conseqüências freqüentemente irreversíveis da mesma. A escolha de um modelo experimental satisfatório a fim de nortear pesquisas com agentes neuroprotetores tem sido a base desses estudos. No presente trabalho foi escolhido o gato como modelo experimental de isquemia e a avaliação foi realizada através do swelling mitocondrial. Os trinta e dois animais utilizados neste experimento, foram divididos em quatro grupos distintos, cada qual com dez animais sendo submetido a um tempo de isquemia, que aumentou progressivamente (15, 30 e 60 minutos), exceto no último grupo com dois animais e que não foi submetido a nenhum procedimento isquemiante. Foram observadas alterações evidentes nas curvas de swelling mitocondrial energizado nos animais submetidos a 60 minutos de isquemia, quando se comparou amostras do lado isquêmico em relação ao controle, isto ficou ainda mais claro quando se adicionou o antibiótico Alameticina durante os ensaios laboratoriais do swelling mitocondrial. Foi possível chegar às seguintes conclusões: o swelling funciona como indicador de diferenciação mitocondrial entre diversos tecidos; a mitocôndria do cérebro, quando exposta ao efeito da Alameticina, apresenta uma sensibilidade diferenciada em relação às dos outros tecidos; a mitocôndria do cérebro submetido a isquemia durante 60 minutos se torna mais sensível à Alameticina; e finalmente, as mitocôndrias do cérebro apresentam uma instalação extremamente rápida da reversão do swelling.
ABSTRACT
To evaluate the ultrastructural changes and the mechanism causing liver injury by lead, light and electron microscopic(LM and EM) examination using Timm sulphide silver method(TSM) was done. Sprague-Dawley rats were divided into a control and 3 experimental groups. The experimental groups were orally administered 0.5% lead acetate(LA). Group 1 received a one time dose of 10 ml of LA by gastric intubation. Groups 2 and 3 continuously received LA instead of drinking water. The control group was composed of 3 rats in each group which did not receive any treatment. Rats of group 1, 2 and 3 and control were sacrificed at 1/2, 1, 1 1/2 hours, 2 days, and at 1, 2, 4, 6 and 8 weeks later, except group 3. Before sacrifice, they were perfused with 0.1% sodium sulphide and 2.5% glutaraldehyde through the abdominal aorta for TSM. The liver was taken for LM and EM examinations. Blood lead concentration began to increase from the 2nd day up to 3.29 microgram/ml at 2nd week, and the urinary delta-ALA level showed a steady increase from the 2nd day. LM and EM examination of liver revealed that absorbed lead granules in group 1 were transported into sinusoidal spaces, Kupffer cells, and the hepatocytes within 1 hour and then disappeared 1/2 hour thereafter. In group 2 deposited lead was found in the hepatocytic cytosol bound to mitochondria. That in turn inhibited mitochondrial respiration with resultant mitochondrial swelling at the 1st week and thereafter at 6th week myelin figure formation and condensation of mitochondria, and peroxisomes were increased at 8th week. Based on these results it can be concluded that a transient intake of subletal dose of LA is biotransformed completely by periportal hepatocytes within 1 1/2 hours, but excessively accumulated lead can induce liver cell injury due to lipid peroxidation of membrane by direct toxic effect of lead and by products of lipid peroxidation. We postulate that lead acetate triggers presumably primarily mitochondrial membrane injury and then other organellar changes may play a role in disturbance of a network of interacting of key events capable of causing cell death.