No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Abstract
Aim: To observe the protective effect of quercetin on rat cardiomyocyte apoptosis induced by adriamycin and explore its possible mechanism. Methods: Cultured neonatal rat cardiomyocytes were randomly divided into six groups: normal control group, adriamycin group, quercetin control group, adriamycin + quercetin (25,50,100 μmol·L-1) groups. The activity of LDH was detected by chromatometry, the cardiomyocyte viability was measured by MTT, the ultrastructure of cardiomyocyte was observed by electron microscope, the expression of protein Bcl-2 and Bax was analyzed by immunocytochemical, and the mRNA and protein of caspase-3 were detected by RT-PCR and Western blot respectively. Results: Compared with the control group, the activity of LDH was increased but the viability of cardiomyocyte was decreased; the expression of Bax and caspase-3 was up-regulated while Bcl-2 was down-regulated in ADR group. Compared with ADR group, the above changes were lightened in adriamycin + quercetin groups. But the quercetin control group, in which cultured myocardial cells only exposed to quercetin without ADR, had no obvious changes. Conclusions: Quercetin significantly inhibits the apoptosis induced by ADR in the cultured myocardial cells. Its mechanism is involved in the apoptosis-related pathways, including caspase-3, Bax and Bcl-2.
Aim: To study the effects of polypeptide P165 on the learning and memorization function and the protein expressions in hippocampal neuron of diabetic mice. Methods: The mice diabetic model was induced by streptozotocin (STZ). Polypeptide 165 (0.07, 0.17, 0.3 mg·kg-1) was administered through a gastric tube every day, whereas the Control and Diabetes Millitus (DM) groups were given the same volume water. The cryostat sections of mice brain were then prepared and immunohistochemically stained using Akt, PI3K, P-CREB, Bcl-2, Bax, CytoC five weeks later subsequent to the water maze test. The hippocampus of mice was insolated to determine protein concentration using Western blot. The protein samples were immunoblotted with antibodies to Bcl-2 and Bax. Results: Circled digit one Morris water maze test: relative to mice in the control group, the swimming time to reach the platform was significantly longer in DM (P < 0.05). The swimming time in the P 165 (0.07, 0.17, 0.3 mg·kg-1) groups, was apparently shorter compared to that of the DM group (P < 0.05). Circled digit two The DM mice with P165 were similar to the control mice in terms of the number of neurons with positive stain of PI3K, Akt, P-CREB, Bcl-2 for survival related proteins. However, the number of neurons with positive stain was significantly higher in the DM with polypeptide 165 group than that in diabetic mice (P <0.01). The number of neurons with positive stain using Bax and CytoC for apoptosis related proteins was significantly lower in the DM with polypeptide 165 group than that in diabetic mice (P < 0.05). The results of Western blot were the same as the Immunohistochemical results. Conclusions: Compared to control group, the expressions of survival related proteins in hippocampal neurons among DM mice decreased but that of apoptosis related proteins increased. They led to the deterioration of the learning and memory function of DM mice. P165 treatment for DM mice could help recover the expressions of protein in hippocampal neuron, and improve the learning and memory function.
Methods: H9c2 cells were treated with 1 μ,mol · L -1 DOX treated for 24 h to establish a myocardial injury model. 10, 20, 40μ,mol · L-1 FA was added 2 h before DOX treatment. Cell viability was measured by cell counter kit (CCK-8). Morphological changes were observed by phase contrast microscope. LDH, CK, MDA, SOD levels were detected by biochemical kits. Intracellular level of reactive oxygen species (ROS) was examined by DCF-DA staining with flow cytometry. Cellular apoptosis was detected by AO-EB staining and DNA agarose gel electrophoresis. The expression of caspase-3, Bax, Bcl-2 was evaluated by Western blot.
Aim: To investigate the protective effects of quercetin (QCT) treatment on sepsis - induced myocar-dial depression and explore its mechanism. Methods: Male Sprague-Dawley rats were randomized to 1 of 3 treatments: sham operation group, CLP group and CLP pretreatment with QCT (10 rats in each group). Rat sepsis was created by cecal ligation puncture (CLP) operation. Left ventricular (LV) performance was measured at 12 hours following CLP operation by cardiac hemodynamic measurements via a catheter placed through right common carotid artery to the left ventricle. The expression of inducible nitric oxide synthase (iNOS) and the level of nitric oxide (NO), and the activity of iNOS of the myocardium was detected. Results: Cardiac function of CLP group rats was de-pressed markedly by measuring the LVSP, LVEDP, and ± dp/dt max at 12 hours following CLP operation. iNOS protein of the myocardium was over-expressed, and the level of nitric oxide (NO), the activity of iNOS of the myocardium were also increased. But pretreatment with QCT could weaken all these effects. Conclusion: The protective effect of QCT against sepsis-induced myocardial depression is associated with inhibiting iNOS overexpression and activity, and decreasing the availability of myocardial NO.
Aim: To observe the protective effects of luteolin-7-0-g lucoside on neonatal rat cardiomyocytes induced by adriamycin (ADR) and explore its mechanism of the action. Methods: Primary cardiomyocytes were isolated from neonatal rats and cultured for 48 h, the cells then were randomly divided into normal control groups, ADR model groups, ADR + luteolin-7-0-glucoside (12.5, 6.25, 3.125 mg·L-1) simultaneously treated groups and ADR + luteolin-7-0-glucoside (12.5, 6.25, 3.125 mg·L-1) pretreated for 4 h groups. The dose and time dependent effects of luteolin-7-0-glucoside on myocardial injury induced by ADR were investigated. The survival rate of myocardial cells was calculated by MTT assay. The leakage of lactate dehydrogenase (LDH), the contents of malondialdehyde (MDA) and the activities of superoxide dimutase (SOD) were measured by respective kits. Results: Compared with model groups, the survival rates of all luteolin-7-0-glucoside treated groups were significantly increased (P < 0.05). The content of LDH leakage was reduced, the activities of SOD were increased, and the content of MDA was reduced in ADR + luteolin-7-0-glucoside (12.5, 6.25 mg·L-1) groups (P < 0.05). In the luteolin-7-0-glucoside 4 h pre-incubation groups the contents of LDH leakage were significantly reduced, activities of SOD were increased, and the contents of MDA were reduced (P < 0.01). Conclusion: Luteolin-7-0-glucoside shows significant protective effects on myocardial damage induced by ADR, and the protective effects can be improved after 4 h s' pretreatment with luteolin-7-0-glucoside. The mechanism of this may be related to the effects of anti-free radical and the inhibition of lipid peroxidation.
Aim: To observe the changes of diaphragm contractility and cytoskeletal proteins titin, nebulin and sarcoplasmic reticulum Ca2+-ATPase gene expressions in adriamycin-induced cytotoxicity in rats. Methods: The animal models of diaphragm damage were duplicated by injecting adriamycin into abdominal cavity one time. Forty male sprague-dawley rats were randomly divided into four groups (n = 10) : Three groups received adriamycin in low, middle and high dosage (10,20 and 40 mg · kg-1 ) respectively. Meanwhile, the normal saline was given to rats in control groups. Three days later, these rats were killed, and the diaphragm was removed by thoracotomy. The diaphragm contractility was assessed in isolated diaphragm strips perfusion by these paramemters including peak twitch tension (Pt), maximum tetanic tension (Po), time to peak contraction (CT), half relaxaion time (1/2RT), maximal rates of contraction (+dt/dtmax) and maximal rates of relaxation (-dt/dt max). The expressions of titin, nebulin and sarcoplasmic reticulum Ca2+-ATPase (SERCA) at mRNA level were detected by RT-PCR analysis. Results: In contrast to those in control group, Po, Pt, ± dt/dt max in the adriamycin group were lower (P < 0.01); CT, 1/2RT in the adriamycin group increased significantly (P <0.01). The levels of titin, nebulin and SERCA gene expressions in middle-dose group were lower than those in control group (P < 0.01 ). Conclusions: The mRNA levels of titin, nebulin and SERCA of diaphragm are down-regulated in adriamycin-induced cytotoxicity in rats. It may be associated with the decline of diaphragm contractility.
Aim: To study the effect and molecular mechanism of pretreatment with COPP on hypoxia/reoxygenation injury of H9c2 myocytes. Methods: H9c2 myocytes model of hypoxia/reoxygenation injury was established and H9c2 myocytes were given COPP pretreatment before hypoxia/reoxygenation. Treatment with Znpp and all-trans retinoic acid (ATRA) inhibited HO-1 and Nrf2-ARE respectively. The level of LDH and CK in cell supernatants were measured. HO-1mRNA expression was analyzed by RT-PCR. HO-1 and Nrf2 protein expressions were analyzed by Western blot. Results: Compared with hypoxia/reoxygenation group, the level of LDH and CK in COPP pretreatment groups decreased significantly and the level of HO-1mRNA, HO-1 protein expression and Nrf2 protein expression in the nucleus significantly increased. Znpp abolished protective effect of COPP pretreatment. ATRA blocked the nuclear accumulation of Nrf2 and decreased HO-1 protein expression that COPP pretreatment induced. Conclusions: COPP can induce HO-1 overexpression which has protective effect on hypoxia/reoxygenation injury of H9c2 myocytes. Its mechanism is related to Nrf2-ARE signaling pathway.
OBJECTIVE: To study the effect of ganoderma lucidum polysaccharides peptide (GLPP) on cultured neonatal cardiomyocytes injured by hypoxia/reoxygenation (H/R). METHODS: Cardiomyocytes from neonatal SD rats aged 1 to 3 d were isolated and cultured. The cardiomyocytes cultured for 3-4 d were randomly divided into control group, H/R group and GLPP treatment group (12.5, 25, 50 and 100 mg·L-1). The survival rate of cells was measured by MTT assay. The morphological change of cells and injury to mitochondria were examined under an electronic microscope. The percentage of apoptosis of cardiomyocytes, labeled with AnnexinV-FITC/PI, was measured by flow cytometry. The fluorescence intensity of intracellular [Ca2+]i was detected respectively with Fluo-3/AM loading by the laser confocal microscope. Intracellular reactive oxygen species (ROS) was determined by a laser confocal microscope with DCFH-DA staining. RESULTS: The survival rate of cardiomyocytes in H/R group was decreased compared with the control group(P<0.05). After treatment with GLPP 12.5, 25, 50 and 100 mg·L-1, the survival rate of cardiomyocytes was increased compared with the H/R group (P<0.01). Mitochondrial injury was observed in cardiomyocytes in H/R group, but was relieved by GLPP. The total percentage of apoptosis in H/R group was increased compared with control group(P< 0.01), and GLPP treatment could decrease the total percentage of apoptosis compared with H/R group (P<0.01). The intracellular [Ca2+], and ROS in the H/R group increased compared with control group (P<0.01). GLPP treatment could decrease intracellular [Ca2+], and ROS compared with H/R group(P< 0.01). CONCLUSION: GLPP may protect cultured neonatal rat cardiomyocytes from injury by H/R. The mechanism might be related to decreasing intracellular ROS and overload of [Ca2+]i.
Aim: To study the effect of beta-carotene (BC) on adriamycin (ADM) induced changes of expression of manganese superoxide dismutase (Mn SOD) mRNA, copper-zinc superoxide dismutase (Cu-Zn SOD) mRNA and glutathione peroxidase (GPx) mRNA in myocardial tissue of rats, and to explore the mechanism of BC antagonized to the reduced activities of Mn SOD, Cu-Zn SOD and GPx in myocardial tissue induced by ADM. Methods: Rats were treated with ADM by intraperitoneal injection (ip, 10.0 mg · kg-1 body weight, only 1 time), and then the ADM treated rats were intervened by BC at different dosage by intragastric perfusion (every day for 14 times, ADM was administered by ip at 12 days). Thiobarbituric acid method, nitrate reductase method, xanthine oxidase method, 5,5′-dithiobis-(2-nitrobenzoic acid) method and hemoglobin-oxidation method were used to determine the contents of malondialdehyde (MDA) and nitric oxide (NO), the activities of Mn SOD, Cu-Zn SOD, GPx and nitric oxide synthase in myocardial tissue, respectively. The expression of Mn SOD mRNA, Cu-Zn SOD mRNA, GPx mRNA and inducible nitric oxide synthase (iNOS) mRNA were detected by reverse transcription- polymerase chain reaction method in myocardial tissue. Results: BC (20.0, 40.0, 80.0 mg · kg-1) has antagonistic effect on increasing the contents of MDA and NO, the expressive level of iNOS mRNA, the activity of iNOS, and reducing the expressive levels of Mn SOD mRNA, Cu-Zn SOD mRNA and GPx mRNA, and reducing the activities of Mn SOD, Cu-Zn SOD and GPx in myocardial tissue induced by ADM (P < 0.01). Conclusion: BC antagonized the reduced expression of Mn SOD mRNA, Cu-Zn SOD mRNA and GPx mRNA in myocardial tissue induced by ADM, thereby antagonized the reduced activities of Mn SOD, Cu-Zn SOD and GPx in myocardial tissue induced by ADM. The mechanism may be related to BC inhibited ADM induced the expression of iNOS mRNA in myocardial tissue, thereby reduced the activity of iNOS, and reduced the generation of NO, and reduced NO inhibited the expression of Mn SOD mRNA, Cu-Zn SOD mRNA and GPx mRNA in myocardial tissue.
Aim: To observe the protective effect and mechanism of quercetin on cardiomyocytes injured by hydrogen dioxide. Methods: 1 The experiment was performed in the Stuff Room of Pharmacology, Jinzhou Medical University from December 2004 to May 2005. 15 SD rats aged 1-3 days old were selected. 2 Hydrogen dioxide injured model was made with purified cultured cardiomyocytes, and the experiment was divided into 6 groups with 6 pores in each group: Normal control group (normal cell was cultivated with only medium of the same volume); 10 g/L Dimathyl sulfoxide group (10 g/L dimathyl sulfoxide); Hydrogen peroxide injured group(200 μmol/L hydrogen peroxide); Hydrogen peroxide + low concentration quercetin group (200 μmol/L hydrogen peroxide + 25 μmol/L quercetin); Hydrogen peroxide + middle concentration quercetin group (200 μmol/L hydrogen peroxide + 50 μmol/L quercetin); Hydrogen peroxide + high concentration quercetin group (200 μmol/L hydrogen peroxide + 50 μmol/L quercetin). The injuring time of hydrogen peroxide (200 μmol/L) was 12 hours. 3 The releasing amounts were measured with lactic dehydrogenase (LDH) method and level of superoxide dismutase (SOD) was assayed with xanthine oxidase method; The contents of malondialdehyde (MDA) were measured with thiobarbituric acid mehod; The contents of nitrogen monoxide were detected with acid isoxidation; The activities of dehydrogenase in mito-chondria were detected with tetrazolium. 4 The differences of measurement data were compared with t test and data among groups were processed with non-paired t test according to the analysis of varience homogeneity. Results: 1 The contents of activity in LDH and MDA: It was significantly higher in the hydrogen peroxide injured group than that in the normal control group, hydrogen peroxide + low, middle, high concentration quercetin group (P < 0.01). 2 The activities of SOD: It was significantly lower in the hydrogen peroxide injured group than that in the hydrogen peroxide + low, middle, high concentration group (P < 0.01). 3 The activities of dehydrogenase in mito-chondria: It was significantly lower in the hydrogen peroxide injured group than that in the hydrogen peroxide + low, middle, high concentration group (P < 0.01). 4The contents of nitrogen monoxide in cardiomyocytes: It was obviously higher in the hydrogen peroxide injured group than that in the normal control group and hydrogen peroxide + high, middle, low concentration quercetin group(P < 0.05). Conclusion: Quercetin has a significant protective effect on anoxia-reoxygenation of cardiomyocytes injured by hydrogen peroxide, which may relate with its antioxidation effects.
Aim: To explore the effect of nimesulide in combination with adriamycin on the proliferation and apoptosis in human hepatocellular carcinoma cell line HepG2. Method: The inhibitory effect of the two drugs on the proliferation of HepG2 was detected with MTT assay. The Jin's formula was used to analyze their synergic inhibitory effect. The morphologic changes were observed by acridine orange fluorescence staining. Cell apoptosis was detected by flow cytometry (FCM). Results: NIM (25, 50, 100 μmol · L-1) in combination with ADM (0.156, 0.313, 0.625 mg · L -1) showed different synergic effects on the proliferation of human hepatoma cell line HepG2 (q > 1.15). It had marked difference between the combined group and the ADM group alone (P < 0.01). After incubation with drugs for 48 h, the cells showed distinctive apoptotic characteristics and the apoptosis rate of the combined group (NIM 100 μmol · L-1 + ADM 2.5 mg · L-1) was higher than those of the group treated with NIM 100 μmol · L-1 or ADM 2.5 mg · L-1 alone (19.6% vs 2.48%, 10.6%). Conclusion: The combination of selective COX-2 inhibitor NIM and ADM can synergetically suppress the proliferation and enhance apoptosis in human hepatoma cell lines HepG 2.
Anthracycline antibiotics, including adriamycin (ADM), are widely used to treat various human cancers, but their clinical use has been limited because of their cardiotoxicity. ADM is especially toxic to heart tissue. The mechanisms responsible for the cardiotoxic effect of ADM have been very/extremely controversial. This review focuses on the participation of free radicals generated by ADM in the cardiotoxic effect. ADM is reduced to a semiquinone radical species by microsomal NADPH-P450 reductase and mitochondrial NADH dehydrogenase. In the presence of oxygen, the reductive semiquinone radical species produces superoxide and hydroxyl radicals. Generally, lipid peroxidation proceeds by mediating the redox of iron. ADM extracts iron from ferritin to form ADM-Fe3+, which causes lipid peroxidation of membranes. These events may lead to disturbance of the membrane structure and dysfunction of mitochondria. However, superoxide dismutase and hydroxyl radical scavengers have little effect on lipid peroxidation induced by ADM-Fe3+. Alternatively, ADM is oxidatively activated by peroxidases to convert to an oxidative semiquinone radical, which participates in inactivation of mitochondrial enzymes or including succinate dehydrogenase and creatine kinase. Here, we discuss the activation of ADM and the role of reductive and oxidative ADM semiquinone radicals in the cardiotoxic effect of this antibiotic.