Effect of Geumgwe-Sinkihwan on Renal Dysfunction in Ischemia/Reperfusion-Induced Acute Renal Failure Mice.

Renal ischemia-reperfusion (I/R) injury is an important cause of acute renal failure (ARF). Geumgwe-sinkihwan (GSH) was recorded in a traditional Chines medical book named "Bangyakhappyeon" in 1884. GSH has been used for treatment for patients with diabetes and glomerulonephritis caused by deficiency of kidney yang and insufficiency of kidney gi. Here we investigate the effects of GSH in mice model of ischemic acute kidney injury. The mice groups are as follows; sham group: C57BL6 male mice, I/R group: C57BL6 male mice with I/R surgery, GSH low group: I/R + 100 mg/kg/day GSH, and GSH high group: I/R + 300 mg/kg/day GSH. Ischemia was induced by clamping both renal arteries and reperfusion. Mice were orally given GSH (100 and 300 mg/kg/day) during 3 days after surgery. Treatment with GSH significantly ameliorated creatinine clearance, creatinine, and blood urea nitrogen levels. Treatment with GSH reduced neutrophil gelatinase associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1), specific renal injury markers. GSH also reduced the periodic acid-Schiff and picro sirius red staining intensity in kidney of I/R group. Western blot and real-time RT-qPCR analysis demonstrated that GSH decreased protein and mRNA expression levels of the inflammatory cytokines in I/R-induced ARF mice. Moreover, GSH inhibited protein and mRNA expression of inflammasome-related protein including NLRP3 (NOD-like receptor pyrin domain-containing protein 3, cryoprin), ASC (Apoptosis-associated speck-like protein containing a CARD), and caspase-1. These findings provided evidence that GSH ameliorates renal injury including metabolic dysfunction and inflammation via the inhibition of NLRP3-dependent inflammasome in I/R-induced ARF mice.

Differential role of nicotinamide adenine dinucleotide deficiency in acute and chronic kidney disease.

BACKGROUND: Nicotinamide adenine dinucleotide (NAD+) is a ubiquitous coenzyme involved in electron transport and a co-substrate for sirtuin function. NAD+ deficiency has been demonstrated in the context of acute kidney injury (AKI). METHODS: We studied the expression of key NAD+ biosynthesis enzymes in kidney biopsies from human allograft patients and patients with chronic kidney disease (CKD) at different stages. We used ischaemia-reperfusion injury (IRI) and cisplatin injection to model AKI, urinary tract obstruction [unilateral ureteral obstruction (UUO)] and tubulointerstitial fibrosis induced by proteinuria to investigate CKD in mice. We assessed the effect of nicotinamide riboside (NR) supplementation on AKI and CKD in animal models. RESULTS: RNA sequencing analysis of human kidney allograft biopsies during the reperfusion phase showed that the NAD+de novo synthesis is impaired in the immediate post-transplantation period, whereas the salvage pathway is stimulated. This decrease in de novo NAD+ synthesis was confirmed in two mouse models of IRI where NR supplementation prevented plasma urea and creatinine elevation and tubular injury. In human biopsies from CKD patients, the NAD+de novo synthesis pathway was impaired according to CKD stage, with better preservation of the salvage pathway. Similar alterations in gene expression were observed in mice with UUO or chronic proteinuric glomerular disease. NR supplementation did not prevent CKD progression, in contrast to its efficacy in AKI. CONCLUSION: Impairment of NAD+ synthesis is a hallmark of AKI and CKD. NR supplementation is beneficial in ischaemic AKI but not in CKD models.

Quercitrin inhibits platelet activation in arterial thrombosis.

BACKGROUND: The ingestion of flavonoids has been reported to be associated with reduced cardiovascular disease risk. Quercitrin is a common flavonoid in nature, and it exhibits antioxidant properties. Although the process of thrombogenesis is intimately related to cardiovascular disease risk, it is unclear whether quercitrin plays a role in thrombogenesis. PURPOSE: The aim of this study was to examine the antiplatelet effect of quercitrin in platelet activation. METHODS: Platelet aggregation, granule secretion, calcium mobilization, and integrin activation were used to assess the antiplatelet activity of quercitrin. Antithrombotic effect was determined in mouse using ferric chloride (FeCl3)-induced arterial thrombus formation in vivo and thrombus formation on collagen-coated surfaces under arteriolar shear in vitro. Transection tail bleeding time was used to evaluate whether quercitrin inhibited primary hemostasis. RESULTS: Quercitrin significantly impaired collagen-related peptide-induced platelet aggregation, granule secretion, reactive oxygen species generation, and intracellular calcium mobilization. Outside-in signaling of αIIbß3 integrin was significantly inhibited by quercitrin in a concentration-dependent manner. The inhibitory effect of quercitrin resulted from inhibition of the glycoprotein VI-mediated platelet signal transduction during cell activation. Further, the antioxidant effect is derived from decreased phosphorylation of components of the TNF receptor-associated factor 4/p47phox/Hic5 axis signalosome. Oral administration of quercitrin efficiently blocked FeCl3-induced arterial thrombus formation in vivo and thrombus formation on collagen-coated surfaces under arteriolar shear in vitro, without prolonging bleeding time. Studies using a mouse model of ischemia/reperfusion-induced stroke indicated that treatment with quercitrin reduced the infarct volume in stroke. CONCLUSIONS: Our results demonstrated that quercitrin could be an effective therapeutic agent for the treatment of thrombotic diseases.

AMPK activation by ozone therapy inhibits tissue factor-triggered intestinal ischemia and ameliorates chemotherapeutic enteritis.

Chemotherapeutic enteritis is a major dose-limiting adverse reaction to chemotherapy, with few effective drugs in clinic. Intestinal ischemic injury plays prominent role in chemotherapeutic enteritis clinically. However, mechanism is not clear. In this article, irinotecan (CPT-11) was used to establish chemotherapeutic enteritis mice model. Western blotting, gelatin zymography, immunohistochemistry (IHC), Laser Doppler flowmetry (LDF) were used to detect the pathogenesis of ischemia-hypoxia injury. CPT-11 increased levels of tissue factor (TF) both in the blood and in intestines, and decreased the intestinal blood flow in mice. Interestingly, the elevation of TF in the blood displayed "double-peak," which was consistent with the intestinal mucosal "double-strike" injury trend. Intestinal microthrombus and mixed thrombus formation were detectable in chemotherapeutic enteritis. Furthermore, ozone therapy relieved chemotherapeutic enteritis in mice. Ozone inhibited TF expression induced by CPT-11 via activating AMPK/SOCS3, and effectively ameliorated the intestinal mucosal injury in mice. Moreover, ozone autotransfusion therapy effectively attenuated chemotherapeutic enteritis and the blood hypercoagulability in patients. For the first time, we proposed that TF-induced thrombotic intestinal ischemic injury is a core trigger pathological mechanism of chemotherapeutic enteritis, and provided a new treatment strategy, ozone therapy, to suppress TF expression and treat chemotherapeutic enteritis.

Neuroprotective Effects of Ginsenosides against Cerebral Ischemia.

Ginseng has been used worldwide as traditional medicine for thousands of years, and ginsenosides have been proved to be the main active components for their various pharmacological activities. Based on their structures, ginsenosides can be divided into ginseng diol-type A and ginseng triol-type B with different pharmacological effects. In this study, six ginsenosides, namely ginsenoside Rb1, Rh2, Rg3, Rg5 as diol-type ginseng saponins, and Rg1 and Re as triol-type ginseng saponins, which were reported to be effective for ischemia-reperfusion (I/R) treatment, were chosen to compare their protective effects on cerebral I/R injury, and their mechanisms were studied by in vitro and in vivo experiments. It was found that all ginsenosides could reduce reactive oxygen species (ROS), inhibit apoptosis and increase mitochondrial membrane potential in cobalt chloride-induced (CoCl2-induced) PC12 cells injury model, and they could reduce cerebral infarction volume, brain neurological dysfunction of I/R rats in vivo. The results of immunohistochemistry and western blot showed that the expression of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), silencing information regulator (SIRT1) and nuclear transcription factor P65 (NF-κB) in hippocampal CA1 region of some ginsenoside groups were also reduced. In general, the effect on cerebral ischemia of Rb1 and Rg3 was significantly improved compared with the control group, and was the strongest among all the ginsenosides. The effect on SIRT1 activation of ginsenoside Rb1 and the inhibition effect of TLR4/MyD88 protein expression of ginsenoside Rb1 and Rg3 were significantly stronger than that of other groups. The results indicated that ginsenoside Rg1, Rb1, Rh2, Rg3, Rg5 and Re were effective in protecting the brain against ischemic injury, and ginsenoside Rb1 and Rg3 have the strongest therapeutic activities in all the tested ginsenosides. Their neuroprotective mechanism is associated with TLR4/MyD88 and SIRT1 activation signaling pathways, and they can reduce cerebral ischemic injury by inhibiting NF-κB transcriptional activity and the expression of proinflammatory cytokines, including interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6).

Cardioprotective effect of saffron extracts against acute doxorubicin toxicity in isolated rabbit hearts submitted to ischemia-reperfusion injury.

Doxorubicin (DOX) is an anthracycline antibiotic routinely used as a chemotherapeutic agent for the treatment of solid tumours. However, DOX possesses an acute and cumulative cardiotoxicity due to free radical production. The present study was designed to investigate the possible protective effects of saffron (Crocus sativus) extracts against DOX-induced acute cardiotoxicity in isolated rabbit hearts submitted to 30 min global ischemia followed by 40 min reperfusion. DOX was delivered during reperfusion, without or with saffron given 5 min before ischemia or at reperfusion. Cardiodynamic, biochemical, and histopathological parameters were determined. In addition, to determine the expression of the AKT/mTOR/4EBP1 pathway, the levels of p38 MAPK and cardiac troponin T in heart homogenates were visualized by Western blotting. DOX administration during 40 min of reperfusion increased ischemic tissue damage, but did not act synergistically. Administration of saffron extracts during the first minutes of reperfusion significantly reduced oxidative myocardial damage, but was less effective when given before ischemia. Subsequent Western blot analysis revealed that saffron administration preserved cardiac troponin T proteins, inhibited the p38 MAPK pathway, and activated the AKT/mTOR/4EBP1 pathway in reperfusion- and DOX-treated rabbit hearts. In conclusion, saffron extracts, acting through antioxidant and antiapoptotic mechanisms, exhibited a protective effect against DOX-induced cardiotoxicity under ischemic condition.

[Iron overload and cardiotoxicity: from thalassemia to reperfusion damage]. / Ferro e cardiotossicità: dalla talassemia al danno da riperfusione.

The role of iron toxicity is well known in gastroenterology and hematology: hemochromatosis, thalassemia major and myelodysplastic syndromes represent iron toxicity models with evidence of serious damages to target organs such as the heart, the liver and endocrine tissues. Iron chelation therapy has dramatically changed the survival rate of thalassemia major since the introduction of desferoxamine with quantitative assessment of tissue iron overload by magnetic resonance imaging. Reperfusion hemorrhage is an independent predictor of left ventricular remodeling after acute myocardial infarction. Hemorrhage may be a source of iron toxicity and a mediator of inflammation, directly contributing to left ventricular remodeling. Iron chelation may potentially alleviate these cardiotoxic effects. Cardiac magnetic resonance imaging can provide insights into miocrovascular obstruction, hemorrhage and iron chelation.

Effects of babassu nut oil on ischemia/reperfusion-induced leukocyte adhesion and macromolecular leakage in the microcirculation: observation in the hamster cheek pouch.

BACKGROUND: The babassu palm tree is native to Brazil and is most densely distributed in the Cocais region of the state of Maranhão, in northeastern Brazil. In addition to the industrial use of refined babassu oil, the milk, the unrefined oil and the nuts in natura are used by families from several communities of African descendants as one of the principal sources of food energy. The objective of this study was to evaluate the effects of babassu oil on microvascular permeability and leukocyte-endothelial interactions induced by ischemia/reperfusion using the hamster cheek pouch microcirculation as experimental model. METHODS: Twice a day for 14 days, male hamsters received unrefined babassu oil (0.02 ml/dose [BO-2 group], 0.06 ml/dose [BO-6 group], 0.18 ml/dose [BO-18 group]) or mineral oil (0.18 ml/dose [MO group]). Observations were made in the cheek pouch and macromolecular permeability increase induced by ischemia/reperfusion (I/R) or topical application of histamine, as well as leukocyte-endothelial interaction after I/R were evaluated. RESULTS: The mean value of I/R-induced microvascular leakage, determined during reperfusion, was significantly lower in the BO-6 and BO-18 groups than in the MO one (P < 0.001). In addition, histamine-induced increase of microvascular permeability was significantly less pronounced in BO groups compared to MO one. No significant differences among groups in terms of leukocyte adhesion, concentrations of tumor necrosis factor alpha, interleukin 1, and interleukin 6 were found. CONCLUSIONS: Our findings suggest that unrefined babassu oil reduced microvascular leakage and protected against histamine-induced effects in postcapillary venules and highlights that these almost unexploited nut and its oil might be secure sources of food energy.

TMP prevents retinal neovascularization and imparts neuroprotection in an oxygen-induced retinopathy model.

PURPOSE: To evaluate the effects of tetramethylpyrazine (TMP) on retinal neovascularization (NV) and neuroprotection in an oxygen-induced retinopathy (OIR) model. METHODS: Neonatal C57BL/6J mice were subjected to 75% oxygen from postnatal day 7 (P7) to P12 and then returned to room air. TMP (200 mg/kg) or normal saline was given daily from P12 to P17. Immunostaining, HE staining, TUNEL assay, and RT-PCR were used to assess the effects of TMP on retinal neurovascular repair. RESULTS: TMP effectively prevented pathologic NV and accelerated physiologic revascularization by enhancing the formation of endothelial tip cells at the edges of the repairing capillary networks and preserving the astrocytic template in the avascular retina. TMP also prevented morphologic changes and significantly decreased TUNEL-positive cells in the avascular retina by rescuing neurons such as amacrine, rod bipolar, horizontal, and Müller cells. In TMP-treated mice retinas, there was a less obvious loss of amacrine cell bodies and their distinct bands; the number of both rod bipolar and horizontal cell bodies, as well as the density of their dendrites in the outer plexiform layer, was greater than that in OIR control mice. TMP not only decreased the loss of alignment of Müller cell bodies and distortion of processes but reduced the reactive expression of GFAP in Müller cells. Furthermore, HIF-1α and VEGF mRNA expression were downregulated in TMP-treated mice retinas. CONCLUSIONS: TMP improved neurovascular recovery by preventing NV and protecting retinal astroglia cells and neurons from ischemia-induced cell death partially due to its downregulation of HIF-1α and VEGF mRNA expression.

[Protective effect of shenqi fuzheng injection on cerebral ischemia/reperfusion injured aged rats].

OBJECTIVE: To study the protective effects of Shenqi Fuzheng Injection (SFI) on cerebral ischemia/reperfusion injured aged rats. METHODS: Aged SD male rats, weighing 200-300 g, were randomly divided into 4 groups: the model group, the sham-operative group, the nimodipine positive control group (abbreviated as nimodipine group) and the SFI group. Focal cerebral ischemia/reperfusion injured rat model was established by modified Longa method. SFI was administered by intravenous dripping 1 week before ischemia. Nervous function disorder, brain infarction area, serum lactate dehydrogenase (LDH) and creatine kinase (CK) levels, brain contents of Ca2+ , water, MDA and SOD levels were observed 3 hrs after ischemia and 3 hrs after reperfusion. RESULTS: perimental results showed that SFI could obviously improve the deficit of nerve function, decrease water content of brain, reduce the infarction area of brain, and inhibit Ca2 + aggregation. LDH and CK levels in serum and MDA in brain were obviously lower than those in the model group and SOD activity in cerebral tissue was obviously higher than that in the model group. CONCLUSION: SFI had protective effect on cerebral ischemia/reperfusion injured aged rats, whose mechanism might be related to the inhibition of lipid peroxidation and Ca2+ aggregation.