Aqueous fish extract increases survival in the mouse model of cytostatic toxicity

<p>Abstract</p> <p>Background</p> <p>Treatment of cancer patients with anthracycline antibiotic doxorubicin (DOX) may be complicated by development of acute and chronic congestive heart failure (CHF), malignant arrhythmias and death. The aim of this study was to test whether an aqueous low molecular weight (LMW) extract from cod muscle decreases acute mortality in the mouse model of acute CHF caused by DOX.</p> <p>Methods</p> <p>A LMW fraction (<500 Da) of the aqueous phase of cod light muscle (AOX) was used for treatment of male BALB/c mice (~25 g, n = 70). The animals were divided into four groups, DOX + AOX (n = 20), DOX + saline (NaCl) (n = 30), NaCl + AOX (n = 10) and NaCl only (n = 10). Echocardiography was performed in the separate subgroups (DOX treated n = 6 and controls n = 6) to verify the presence and the grade of acute CHF. The cod extract was delivered by subcutaneously implanted osmotic minipumps over the period of 2 weeks. High-dose injection of DOX was administered to randomly selected animals. The animals received single intraperitoneal injection of DOX (25 mg/kg) and were followed over two weeks for mortality.</p> <p>Results</p> <p>Mortality rate was 68% lower (p < 0.05) in the mice treated with the extract. The analyses of cod extract have shown strong antioxidative effect <it>in vitro</it>.</p> <p>Conclusion</p> <p>The aqueous LMW cod muscles extract decreases mortality in the mouse model of DOX induced acute CHF. This effect may be mediated by cardioprotection through antioxidative mechanisms.</p

Transplanting embryonic stem cells onto damaged human corneal endothelium

AIM To investigate whether human embryonic stem cells (hESCs) could be made to attach, grow and differentiate on a human Descemet’s membrane (DM). METHODS Spontaneously differentiated hESCs were transferred onto a human corneal button with the endothelial layer removed using ocular sticks. The cells were cultured on a DM for up to 15 d. The genetically engineered hESC line expressed green fluorescent protein, which facilitated identification during the culture experiments, tissue preparation, and analysis. To detect any differentiation into human corneal endothelial-like cells, we analysed the transplanted cells by immunohistochemistry using specific antibodies. RESULTS We found transplanted cells form a single layer of cells with a hexagonal shape in the periphery of the DM. The majority of the cells were negative for octamer-binding transcription factor 4 but positive for paired box 6 protein, sodium potassium adenosine triphosphatase (NaKATPase), and Zona Occludens protein 1. In four of the 18 trials, the transplanted cells were found to express CK3, which indicates that the stem cells differentiated into corneal epithelial cells in these cases. CONCLUSION It is possible to get cells originating from hESCs to become established on a human DM, where they grow and differentiate into corneal endothelial-like cells in vitro.De Blindas Vänner, Gothenburg, and Greta Bergs Foundation, Lerum (to Charles Hanson); University of Akureyri Research Fund, the KEA Fund, and the Icelandic Council on Ageing (to Arsaell Arnarsson); and Gothenburg Medical Society, the Medical Faculty of the University of Gothenburg and the Herman Svensson Foundation (to Ulf Stenevi)Peer Reviewe

Improved bioenergetic recovery during experimental ischemia and reperfusion by irradiation

Prolonged ischemia and reperfusion frequently occur during clinical operations. The bioenergetic status decreases during ischemia and reactive oxygen species (ROS) are formed during reperfusion, which may lead to irreversible tissue injury. During prolonged ischemia, such as in complex microsurgical operations, tissue injury should be minimized to improve the chance of full recovery and function. Irradiation has previously been shown to improve functional recovery of cold-stored rat hearts via conservation of ATP. In this thesis, we used photons at 634 nm produced from a singlet oxygen system to investigate whether irradiation improves the bioenergetic status in skeletal muscle and graft hearts and decreases ROS in monocytes, and thus decreases tissue injury. The effect of irradiation on bioenergetic status was examined in rat rectus femoris muscle in vitro following 5 h ischemia. Phosphocreatine (PCr), ATP and inorganic phosphate (Pi) levels were measured using high resolution 11.75T 31P magnetic resonance spectroscopy (MRS). PCr and ATP were significantly higher in the irradiated groups than in the non-irradiated group, but no difference in Pi was observed. The effect of irradiation on bioenergetic status was examined in rat rectus femoris muscle in vivo following 4 h ischemia and 1 reperfusion. ATP, PCr and Pi levels were measured using 2.35T 31P MRS. After 4 h ischemia, ATP levels in the irradiated group were significantly higher than in the non- irradiated group, but no difference in PCr/(PCr+Pi) levels were observed. After 1 h reperfusion, ATP and PCr/(PCr+Pi) levels in the irradiated groups were significantly higher than in the non-irradiated groups. Blood-perfusion was measured using laser Doppler flowmetry and did not differ between the groups. The effect of irradiation on xenografts was examined in vivo following heart xenotransplantation from hamster to rat. PCr and ATP levels were measured daily using 2.35T 31P MRS over 4 days. Irradiation of xenografts before reperfusion preserved the energetic status of hamster grafts, as demonstrated by a significantly higher PCr/ATP ratio in the irradiated group than in the non-irradiated group on the first postoperative day. However, irradiation did not delay the rejection process in this experimental model. Finally, the effect of irradiation was examined in human monocytes. Intracellular ROS, nitric oxide (NO) release and ATP were measured using chemiluminescence assays. iNOS and eNOS mRNA levels were measured using reverse transciption PCR. NO levels were significantly higher in the irradiated group than in the non-irradiated group, but no differences in iNOS or eNOS mRNA were observed. Intracellular ROS release was significantly lower in the irradiated group than in the non-irradiated group, and there was no difference in ATP levels. The salvaging effect of irradiation may have a wide range of clinical applications, for example in complex microsurgery and transplantation surgery

Inhibitory effect of known antioxidants and of press juice from herring (Clupea harengus) light muscle on the generation of free radicals in human monocytes

Reactive oxygen species (ROS) can cause oxidative stress, which has been linked to various diseases. It has been suggested that antioxidant-rich foods can reduce such oxidative stress. However, the lack of suitable model systems to screen for in vivo effects of food-derived antioxidants has prevented a clear consensus in this area. In this study, the aim was to use a single-cell model system (human monocyte) to evaluate whether certain pure antioxidants and complex muscle extracts (herring light muscle press juice, PJ) could prevent ROS formation under in vivo like conditions. ROS were excreted from the monocytes upon stimulation with phorbol myristate acetate and were then detected as isoluminol-enhanced chemiluminescence (CL). Adding 2000 units of catalase and 50 units of superoxide dismutase to the monocytes model lowered the CL response by 35 and 86%, respectively. Ascorbate (14.1 mM) lowered the response by 99%, alpha-tocoperhol (188 microM) by 37%, and Trolox (50 microM) by almost 100%. Crude herring PJ gave a dose-dependent reduction in the CL response. At 10, 100, and 1000 times dilution, the PJ reduced the CL signal by 93, 60.5, and 10.6%. PJ fractionated into low molecular weight (LMW) (<1000 Da) and high molecular weight (>3500 Da) fractions decreased the CL response by 52.9 and 71.4%, respectively, at a 100-fold dilution. Evaluation of the PJ samples in the oxygen radical absorbance capacity test indicated that proteins may be the primary radical scavenging compounds of PJ, whereas the ROS-preventing effect obtained from the LMW fraction may also be attributed to other mechanisms. Thus, this study proved that the monocyte assay can be a useful tool for studying whether food-derived antioxidants can limit ROS production under physiologically relevant conditions. It also showed that herring contains numerous aqueous compounds demonstrating antioxidative effects in the monocyte model system