Ginkgo biloba extract (EGb 761) attenuates lung injury induced by intestinal ischemia/reperfusion in rats: Roles of oxidative stress and nitric oxide

Ac2-26 Reduced Lung Injury After Cardiopulmonary Bypass via the AKT1/GSK3β/eNOS Pathway

INTRODUCTION

Cardiopulmonary bypass (CPB) leads to severe inflammation and lung injury. Our previous study showed that Ac2-26 (an active n-terminal peptide of Annexin A1) can reduce acute lung injury. The aim of this study was to evaluate the effect of Ac2-26 on lung injury in CPB rats.

METHODS

Forty rats were randomly divided into the sham, CPB, Ac, Ac/serine/threonine kinase 1 (AKT1), and Ac/ glycogen synthase kinase (GSK)-3β groups. The rats in the sham group only received anesthesia, intubation, and cannulation. The rats in the other 4 groups received the standard CPB procedure. The rats in the CPB, Ac, Ac/AKT1, and Ac/GSK3β groups were immediately injected with saline, Ac2-26 (1 mg/kg), Ac2-26 combined with short hairpin RNA (AKT1), or Ac2-26 combined with a GSK3β inhibitor after CPB. At 12 h after the end of CPB, the PaO2/ fraction of inspired oxygen ratio, wet/dry weight ratio and protein content in the bronchoalveolar lavage fluid (BALF) were recorded. The numbers of macrophages and neutrophils in the BALF and blood were determined. Cytokine levels in the blood and BALF were investigated. Lung tissue histology and apoptosis were estimated. The expression of nuclear factor kappa- B, AKT1, GSK3β, endothelial nitric oxide synthase and apoptosis-related proteins was analyzed. The survival of all the rats was recorded.

RESULTS

Compared with the rats in the sham group, all the parameters examined worsened in the rats that received CPB. Compared with those in the CPB group, Ac2-26 significantly improved pulmonary capillary permeability, reduced cytokine levels, and decreased histological scores and apoptosis. The protective effect of Ac2-26 on lung injury was significantly reversed by AKT1 short hairpin RNA or a GSK3β inhibitor.

CONCLUSIONS

Ac2-26 significantly reduced lung injury and inflammation after CPB. The protective effect of Ac2-26 mainly depended on the AKT1/GSK3β/endothelial nitric oxide synthase pathway.

Ac2-26 reduced the liver injury after cardiopulmonary bypass in rats via AKT1/GSK3β/eNOS pathway

OBJECTIVE

About 10% of patients after cardiopulmonary bypass (CPB) would undergo acute liver injury, which aggravated the mortality of patients. Ac2-26 has been demonstrated to ameliorate organic injury by inhibiting inflammation. The present study aims to evaluate the effect and mechanism of Ac2-26 on acute liver injury after CPB.

METHODS

A total of 32 SD rats were randomized into sham, CPB, Ac, and Ac/AKT1 groups. The rats only received anesthesia, and rats in other groups received CPB. The rats in Ac/AKT1 were pre-injected with the shRNA to interfere with the expression of AKT1. The rats in CPB were injected with saline, and rats in Ac and Ac/AKT1 groups were injected with Ac2-26. After 12 h of CPB, all the rats were sacrificed and the peripheral blood and liver samples were collected to analyze. The inflammatory factors in serum and liver were detected. The liver function was tested, and the pathological injury of liver tissue was evaluated.

RESULTS

Compared with the sham group, the inflammatory factors, liver function, and pathological injury were worsened after CPB. Compared with the CPB group, the Ac2-26 significantly decreased the pro-inflammatory factors and increased the anti-inflammatory factor, improved liver function, and ameliorated the pathological injury. All the therapeutic effects of Ac2-26 were notably attenuated by the shRNA of AKT1. The Ac2-26 increased the GSK3β and eNOS, and this promotion was inhibited by the shRNA.

CONCLUSION

The Ac2-26 significantly treated the liver injury, inhibited inflammation, and improved liver function. The effect of Ac2-26 on liver injury induced by CPB was partly associated with the promotion of AKT1/GSK3β/eNOS.

Ac2-26 activated the AKT1/GSK3β pathway to reduce cerebral neurons pyroptosis and improve cerebral function in rats after cardiopulmonary bypass

BACKGROUND

Cardiopulmonary bypass (CPB) results in brain injury, which is primarily caused by inflammation. Ac2-26 protects against ischemic or hemorrhage brain injury. The present study was to explore the effect and mechanism of Ac2-26 on brain injury in CPB rats.

METHODS

Forty-eight rats were randomized into sham, CPB, Ac, Ac/AKT1, Ac/GSK3βi and Ac/AKT1/GSK3βa groups. Rats in sham group only received anesthesia and in the other groups received standard CPB surgery. Rats in the sham and CPB groups received saline, and rats in the Ac, Ac/AKT1, Ac/GSK3βi and Ac/AKT1/GSK3βa groups received Ac2-26 immediately after CPB. Rats in the Ac/AKT1, Ac/GSK3βi and Ac/AKT1/GSK3βa groups were injected with shRNA, inhibitor and agonist of GSK3β respectively. The neurological function score, brain edema and histological score were evaluated. The neuronal survival and hippocampal pyroptosis were assessed. The cytokines, activity of NF-κB, S100 calcium-binding protein β(S100β) and neuron-specific enolase (NSE), and oxidative were tested. The NLRP3, cleaved-caspase-1 and cleaved-gadermin D (GSDMD) in the brain were also detected.

RESULTS

Compared to the sham group, all indicators were aggravated in rats that underwent CPB. Compared to the CPB group, Ac2-26 significantly improved neurological scores and brain edema and ameliorated pathological injury. Ac2-26 reduced the local and systemic inflammation, oxidative stress response and promoted neuronal survival. Ac2-26 reduced hippocampal pyroptosis and decreased pyroptotic proteins in brain tissue. The protection of Ac2-26 was notably lessened by shRNA and inhibitor of GSK3β. The agonist of GSK3β recovered the protection of Ac2-26 in presence of shRNA.

CONCLUSIONS

Ac2-26 significantly improved neurological function, reduced brain injury via regulating inflammation, oxidative stress response and pyroptosis after CPB. The protective effect of Ac2-26 primarily depended on AKT1/ GSK3β pathway.

The molecular mechanisms of ginkgo (Ginkgo biloba) activity in signaling pathways: A comprehensive review

BACKGROUND

One of the most unique plants that have ever grown on the planet is Ginkgo biloba L., a member of the Ginkgoaceae family with no close living relatives. The existence of several differently structured components of G. biloba has increased the chemical variety of herbal therapy. Numerous studies that investigated the biochemical characteristics of G. biloba suggest this plant as a potential treatment for many illnesses.

PURPOSE

Review the molecular mechanisms involved in the signaling pathways of G. biloba activity in varied circumstances and its potential as a novel treatment for various illnesses.

METHODS

Studies focusing on the molecular processes and signaling pathways of compounds and extracts of G. biloba were found and summarized using the proper keywords and operators from Google Scholar, PubMed, Web of Science, and Scopus without time restrictions.

RESULTS

G. biloba exerts its effects through its anti-inflammatory, anti-apoptotic, anti-cancer, neuroprotective, cardioprotective, hepatoprotective, antiviral, antibacterial, pulmoprotective, renoprotective, anti-osteoporosis, anti-melanogenic, retinoprotective, otoprotective, adipogenic, and anti-adipogenic properties. The most important mechanisms involved in these actions are altering the elevation of ROS formation, inhibiting NADPH oxidases activation, altering the expression of antioxidant enzymes, downregulating MAPKs (p38 MAPK and ERK, and JNK) and AP-1, increasing cAMP, inactivating Stat5, activating the AMPK signaling pathway, affecting Stat3/JAK2, NF-κB, Nrf-2, mTOR, HGF/c-Met, Wnt/β-catenin and BMP signaling pathways, and changing the mitochondrial transmembrane potential, the Bax/Bcl-2 ratio, the release of Cyc from mitochondria to cytosol, the protein cleavage of caspases 3, 7, 8, 9, and 12, poly (ADP-ribose) polymerase, and MMPs levels.

CONCLUSIONS

G. biloba and its components have gained attention in recent years for their therapeutic benefits, such as their anti-inflammatory, antioxidant, anti-apoptotic, and apoptotic effects. By understanding their molecular mechanisms and signaling pathways, potential novel medicines might be developed in response to the rising public desire for new therapies.

Annexin A1 peptide Ac2-26 mitigates ventilator-induced lung injury in acute respiratory distress syndrome rats and partly depended on the endothelial nitric oxide synthase pathway

PURPOSE

Although mechanical ventilation is an essential support for acute respiratory distress syndrome (ARDS), ventilation also leads to ventilator-induced lung injury (VILI). This study aimed to estimate the effect and mechanism of Annexin A1 peptide (Ac2-26) on VILI in ARDS rats.

METHODS

Thirty-two rats were randomized into the sham (S), mechanical ventilation (V), mechanical ventilation/Ac2-26 (VA), and mechanical ventilation/Ac2-26/L-NIO (VAL) groups. The S group only received anesthesia, and the other three groups received endotoxin and then ventilation for 4 h. Rats in the V, VA and VAL groups received saline, Ac2-26, and A c2-26/N5-(1-iminoethyl)-l-ornithine (L-NIO), respectively.

RESULTS

All indexes deteriorated in the V, VA and VAL groups compared with the S group. Compared with V group, the PaO2/FiO2 ratio was increased, but the wet-to-dry weight ratio and protein levels in bronchoalveolar lavage fluid were decreased in the VA group. The inflammatory cells and proinflammatory factors were reduced by Ac2-26. The oxidative stress response, lung injury and apoptosis were also decreased by Ac2-26 compared to V group. All improvements of Ac2-26 were partly reversed by L-NIO.

CONCLUSIONS

Ac2-26 mitigates VILI in ARDS rats and partly depended on the endothelial nitric oxide synthase pathway.

The Restoring Effect of Human Umbilical Cord-Derived Mesenchymal Cell-Conditioned Medium (hMSC-CM) against Carbon Tetrachloride-Induced Pulmonary Fibrosis in Male Wistar Rats

Objective

Pulmonary toxicity induced by CCl₄, a model of idiopathic pulmonary fibrosis (IPF), leads to tissue remodeling and inflammation. Human umbilical cord mesenchymal cell-conditioned medium (hMSC-CM) is a potent anti-inflammatory, antioxidative, and antifibrotic agent.

Methods

Forty male Wistar rats were assigned to the control (C), olive oil control (C.O) (hMSC-CM), control (C.Ms), fibrosis (fb), and fibrosis with hMSC-CM (f.Ms) treatment groups. The groups C, C.O, and C.Ms received PBS (200 µl), olive oil (1 ml/kg), and hMSC-CM (100 μg protein/kg), respectively. The fibrosis group was administered with only CCl4 (1 ml/kg). The last group, f.Ms was treated with CCl₄ (1 ml/kg) and 100 μg protein/kg IV hMSC-CM. While the treatment with olive oil and CCl₄ was performed for 2 days/week from the first week for 12 weeks, the treatment with PBS and hMSC-CM was carried out 2 days/week from week 4^th to week 12^th. The effect of the UC-MSC culture medium treatment on the lung was evaluated by assessing lysyl oxidase (LOX), tumor necrosis factor-alpha (TNF-α), and transforming growth factor-β1 (TGF-β1) genes, and proteins expression by real-time RCR and western blotting, respectively.

Results

Lysyl oxidase (LOX), tumor necrosis factor-alpha (TNF-α), transforming growth factor-b1 (TGF-β1), malondialdehyde (MDA), and oxidative stress levels were markedly higher in the fibrosis group than in the control groups (p ≤ 0.001). Additionally, glutathione (GSH) in the fibrosis group was markedly lower than those in the control groups (p ≤ 0.001). Fibrosis in the UC-MSC treatment group had milder histopathological injuries than in the fibrosis group.

Conclusion

hMSC-MSC as a strong anti-inflammatory, antioxidative, and antifibrotic decreases the level of oxidative stress, proinflammatory cytokines, and MDA causing a restoring effect against CCl₄-induced pulmonary fibrosis.

OUP accepted manuscript

Acute lung injury has been reported following various chemotherapeutic agents administration. Several pathways for lung injury have been speculated however, the exact mechanism of the lung injury induced by methotrexate (MTX) is yet to be defined. The potential protective effect of Ginkgo biloba extract (GB), a Chinese herbal medicine, against MTX-induced lung injury is still not reported. Therefore, this study was performed to examine the possible implication of NLRP3 inflammasome and miRNA-21 in the pathogenesis of the MTX-induced lung injury as well as the protective role of GB in ameliorating the induced lung injury. Rats received GB (100 mg/kg/day, orally) for 10 days and MTX (20 mg/kg single dose, intraperitoneally) on the fifth day. MTX-induced lung injury was manifested by lung histopathology. MTX exhibited a marked increase in lung malondialdehyde beside a notable decrease in lung reduced glutathione. Moreover, MTX injection activated the lung NLRP3 inflammasome by significant upregulation of the NLRP3, ASC, caspase-1 lung mRNA expressions and protein levels in addition to lung NF-kBp65 protein expression, and miRNA-21 expression when compared with the normal control group. However, GB administration mitigated lung injury and inhibited the NLRP3 activation. This study is the first report to reveal the involvement of NLRP3 inflammasome in the pathogenesis of MTX-induced lung injury and also to show that the administration of GB alleviates the lung injury induced by MTX via suppressing the oxidative stress, restoring the antioxidant activity, blocking the NLRP3/ASC/Caspase-1 signaling and downregulating the NF-kBp65 protein expression ae well as miRNA-21 expression in lung tissue.

Ac2-26 mitigated acute respiratory distress syndrome rats via formyl peptide receptor pathway

BACKGROUND

Acute respiratory distress syndrome (ARDS) is characterized by severe local and systemic inflammation. Ac2-26, an Annexin A1 Peptide, can reduce the lung injury induced by reperfusion via the inhibition of inflammation. The present study aims to evaluate the effect and mechanism of Ac2-26 in ARDS.

METHODS

Thirty-two rats were anaesthetized and randomized into four groups: sham (S), ARDS (A), ARDS/Ac2-26 (AA), and ARDS/Ac2-26/BOC-2 (AAB) groups. Rats in the S group received saline for intratracheal instillation, while rats in the other three groups received endotoxin for intratracheal instillation, in order to prepare the ARDS and inject the saline, Ac2-26, and Ac2-26 combined with BOC-2. After 24 h, the PaO2/FiO2 ratio was calculated. The lung tissue wet-to-dry weight ratio and the protein level in bronchoalveolar lavage fluid (BALF) were tested. Then, the cytokines in BALF and serum, and the inflammatory cells in BALF were investigated. Afterwards, the oxidative stress response and histological injury was evaluated. Subsequently, the epithelium was cultured and analyzed to estimate the effect of Ac2-26 on apoptosis.

RESULTS

Compared to the S group, all indexes worsened in the A, AA, and AAB groups. Furthermore, compared to the S group, Ac2-26 significantly improved the lung injury and alveolar-capillary permeability, and inhibited the oxidative stress response. In addition, Ac2-26 reduced the local and systemic inflammation through the regulation of pro- and anti-inflammatory cytokines, and the decrease in inflammatory cells in BALF. Moreover, Ac2-26 inhibited the epithelium apoptosis induced by LPS through the modulation of apoptosis-regulated proteins. The protective effect of Ac2-26 on ARDS was partially reversed by the FPR inhibitor, BOC-2.

CONCLUSION

Ac2-26 reduced the lung injury induced by LPS, promoted alveolar-capillary permeability, ameliorated the local and systemic inflammation, and inhibited the oxidative stress response and apoptosis. The protection of Ac2-26 on ARDS was mainly dependent on the FPR pathway.

The α2AR/Caveolin-1/p38MAPK/NF-κB axis explains dexmedetomidine protection against lung injury following intestinal ischaemia-reperfusion

Intestinal ischaemia-reperfusion (I/R) injury can result in acute lung injury due to ischaemia and hypoxia. Dexmedetomidine (Dex), a highly selective alpha2-noradrenergic receptor (α2AR) agonist used in anaesthesia, is reported to regulate inflammation in organs. This study aimed to investigate the role and mechanism of Dex in lung injury caused by intestinal I/R. After establishing a rat model of intestinal I/R, we measured the wet-to-dry specific gravity of rat lungs upon treatments with Dex, SB239063 and the α2AR antagonist Atipamezole. Moreover, injury scoring and histopathological studies of lung tissues were performed, followed by ELISA detection on tumour necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 expression. Correlation of Caveolin-1 (Cav-1) protein expression with p38, p-p38, p-p65 and p65 in rat lung tissues was analysed, and the degree of cell apoptosis in lung tissues after intestinal I/R injury was detected by TUNEL assay. The lung injury induced by intestinal I/R was a dynamic process. Moreover, Dex had protective effects against lung injury by mediating the expression of Cal-1 and α2A -AR. Specifically, Dex promoted Cav-1 expression via α2A -AR activation and mitigated intestinal I/R-induced lung injury, even in the presence of Atipamezole. The protective effect of Dex on intestinal I/R-induced lung injury was also closely related to α2A -AR/p38 mitogen-activated protein kinases/nuclear factor-kappaB (MAPK/NF-κB) pathway. Dex can alleviate pulmonary inflammation after in intestinal I/R by promoting Cav-1 to inhibit the activation of p38 and NF-κB. In conclusion, Dex can reduce pulmonary inflammatory response even after receiving threats from both intestinal I/R injury and Atipamezole.

Diannexin Can Ameliorate Acute Respiratory Distress Syndrome in Rats by Promoting Heme Oxygenase-1 Expression

Background

The recombinant protein diannexin can inhibit platelet-mediated events, which contribute to acute respiratory distress syndrome (ARDS). Here, we investigated the effect of diannexin and its effect on heme oxygenase-1 (HO-1) in ARDS.

Methods

A total of 32 rats were randomized into sham, ARDS, diannexin (D), and diannexin+HO-1 inhibitor (DH) groups. Alveolar-capillary permeability was evaluated by testing the partial pressure of oxygen to fraction of inspired oxygen (PaO₂/FiO₂) ratio, lung wet/dry weight ratio, and protein levels in the lung. Inflammation was assessed by measuring cytokine levels in the bronchial alveolar lavage fluid (BALF) and serum and nuclear factor-κB (NF-κB) in the lung tissue. Inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), and myeloperoxidase (MPO) were measured to evaluate the oxidative stress response. Lung tissue pathology and apoptosis were also evaluated. We measured HO-1 expression in the lung tissue to investigate the effect of diannexin on HO-1 in ARDS.

Results

Compared with the ARDS group, diannexin improved PaO₂/FiO₂, lung wet/dry weight ratio, and protein levels in the BALF and decreased levels of cytokines and NF-κB in the lung and serum. Diannexin inhibited the oxidative stress response and significantly ameliorated pathological lung injury and apoptosis. The partial reversal of diannexin effects by a HO-1 inhibitor suggests that diannexin may promote HO-1 expression to ameliorate ARDS.

Conclusions

We showed that diannexin can improve alveolar-capillary permeability, inhibit the oxidative stress response and inflammation, and protect against ARDS-induced lung injury and apoptosis.

Alpha 1-antitrypsin for treating ventilator-associated lung injury in acute respiratory distress syndrome rats

Purpose: Mechanical ventilation (MV) is an essential life support tool for patients with acute respiratory distress syndrome (ARDS). However, MV for ARDS can result in ventilator-induced lung injury (VILI). This study aimed to assess whether alpha 1-antitrypsin (AAT) can reduce VILI in ARDS rats. Materials and Methods: Rats were randomly divided into five groups: the sham (S) group, MV (V) group, lipopolysaccharide (LPS) (L) group, MV/LPS (VL) group and MV/AAT (VA) group. Rats in the S group were anesthetized. The rats in the L group received LPS but not ventilation, the rats in the V group received only MV, and the rats in the VL and VA groups received LPS and MV. Additionally, the rats in the VA group were treated with AAT, and the other rats were injected with saline. The PaO₂/FiO₂ ratio and the wet/dry weight were assessed. The total protein and neutrophil elastase concentrations and the neutrophil and macrophage counts in bronchoalveolar lavage fluid (BALF) were evaluated. Proinflammatory factors in BALF and ICAM-1 and MIP-2 in serum were also tested. Furthermore, the oxidative stress response was detected, and histological injury and apoptosis were evaluated. Results: All the rats in the V, L and VL groups had significant lung injury, with the VL group exhibiting the most severe injury. Compared with the findings in the VL group, AAT significantly upregulated the PaO₂/FiO₂ ratio but decreased the wet/dry weight ratio and protein levels in BALF. AAT also reduced proinflammatory cytokine levels and inflammatory cell counts in BALF. Lung tissue injury and cell apoptosis were mitigated by AAT. Conclusions: AAT ameliorated VILI in ARDS rats. The protection conferred by AAT may be associated with the anti-inflammatory, antioxidative stress response and anti-apoptotic effects of AAT.

Ac2-26 ameliorates lung ischemia-reperfusion injury via the eNOS pathway

BACKGROUND

Lung ischemia-reperfusion injury (LIRI) is a major complication after lung transplantation. Annexin A1 (AnxA1) ameliorates inflammation in various injured organs. This study aimed to determine the effects and mechanism of AnxA1 on LIRI after lung transplantation.

METHODS

Thirty-two rats were randomized into sham, saline, Ac2-26 and Ac2-26/L groups. Rats in the saline, Ac2-26 and Ac2-26/L groups underwent left lung transplantation and received saline, Ac2-26, and Ac2-26/L-NIO, respectively. After 24 h of reperfusion, serum and transplanted lung tissues were examined.

RESULTS

The partial pressure of oxygen (PaO₂) was increased in the Ac2-26 group compared to that in the saline group but was decreased by L-NIO treatment. In the Ac2-26 group, the wet-to-dry (W/D) weight ratios, total protein concentrations, proinflammatory factors and inducible nitric oxide synthase levels were notably decreased, but the concentrations of anti-inflammatory factors and endothelial nitric oxide synthase levels were significantly increased. Ac2-26 attenuated histological injury and cell apoptosis, and this improvement was reversed by L-NIO.

CONCLUSIONS

Ac2-26 reduced LIRI and improved alveoli-capillary permeability by inhibiting oxygen stress, inflammation and apoptosis. The protective effect of Ac2-26 on LIRI largely depended on the endothelial nitric oxide synthase pathway.

Ginkgo biloba extract for prevention of acute mountain sickness: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

Trials of ginkgo biloba extract (GBE) for the prevention of acute mountain sickness (AMS) have been published since 1996. Because of their conflicting results, the efficacy of GBE remains unclear. We performed a systematic review and meta-analysis to assess whether GBE prevents AMS.

METHODS

The Cochrane Library, EMBASE, Google Scholar and PubMed databases were searched for articles published up to 20 May 2017. Only randomised controlled trials were included. AMS was defined as an Environmental Symptom Questionnaire Acute Mountain Sickness-Cerebral score ≥0.7 or Lake Louise Score ≥3 with headache. The main outcome measure was the relative risk (RR) of AMS in participants receiving GBE for prophylaxis. Meta-analyses were conducted using random-effects models. Sensitivity analyses, subgroup analyses and tests for publication bias were conducted.

RESULTS

Seven study groups in six published articles met all eligibility criteria, including the article published by Leadbetter et al, where two randomised controlled trials were conducted. Overall, 451 participants were enrolled. In the primary meta-analysis of all seven study groups, GBE showed trend of AMS prophylaxis, but it is not statistically significant (RR=0.68; 95% CI 0.45 to 1.04; p=0.08). The I² statistic was 58.7% (p=0.02), indicating substantial heterogeneity. The pooled risk difference (RD) revealed a significant risk reduction in participants who use GBE (RD=-25%; 95% CI, from a reduction of 45% to 6%; p=0.011) The results of subgroup analyses of studies with low risk of bias, low starting altitude (<2500 m), number of treatment days before ascending and dosage of GBE are not statistically significant.

CONCLUSION

The currently available data suggest that although GBE may tend towards AMS prophylaxis, there are not enough data to show the statistically significant effect of GBE on preventing AMS. Further large randomised controlled studies are warranted.

Natural plant products in treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a severe disease characterized by progressive remodeling of distal pulmonary arteries and persistent elevation of pulmonary vascular resistance (PVR), which leads to right ventricular dysfunction, heart failure, and eventually death. Although treatment responsiveness for this disease is improving, it continues to be a life-threatening condition. With the clinical efficacy of natural plant products being fully confirmed by years of practice, more and more recognition and attention have been obtained from the international pharmaceutical industry. Moreover, studies over the past decades have demonstrated that drugs derived from natural plants show unique advantages and broad application prospects in PAH treatment, not to mention the historical application of Chinese traditional medicine in cardiopulmonary diseases. In this review, we focus on summarizing natural plant compounds with therapeutic properties in PAH, according to the extracts, fractions, and pure compounds from plants into categories, hoping it to be helpful for basic research and clinical application.

The effects of S-nitrosoglutathione on intestinal ischemia reperfusion injury and acute lung injury in rats: Roles of oxidative stress and NF-κB

BACKGROUND

Intestinal ischemia and reperfusion (I/R) induces oxidative stress, inflammatory response, and acute lung injury. S-nitrosoglutathione (GSNO), a nitric oxide donor, has been documented to have protective effects on experimental ischemia models.

AIM

The aim of this study was to examine the effect of GSNO on I/R-induced intestine and lung damage and detect the potential mechanisms emphasizing the protective role of GSNO.

METHODS

Intestinal I/R was induced by occluding the superior mesenteric artery for 30 min followed by reperfusion for 180 min. GSNO was administered intravenously before reperfusion period (0.25 mg/kg). The levels of lipid peroxidation, reduced glutathione, and myeloperoxidase (MPO), histopathological evaluation and immunohistochemical expressions of both nuclear factor KappaB (NF-κB) and inducible nitric oxide (iNOS) in intestine and lung tissues were assessed.

RESULTS

Histolopathologic evaluation demonstrated that intestinal I/R induced severe damages in the intestine and the lung tissues. Histopathological scores decreased with GSNO treatment. GSNO treatment reduced lipid peroxidation and MPO levels and inhibited expression of NF-κB and iNOS in the intestine.

CONCLUSION

Our results suggest that GSNO treatment may ameliorate the intestinal and lung injury in rats, at least in part, by inhibiting inflammatory response and oxidative stress.

Budesonide instillation immediately after reperfusion ameliorates ischemia/reperfusion-induced injury in the transplanted lung of rat

PURPOSE

Lung ischemia-reperfusion injury (LIRI) after lung transplantation can lead to primary graft dysfunction. Budesonide can improve endothelial function to reduce lung injury. This study was aimed to examine the effects of budesonide on LIRI and potential mechanisms.

METHODS

Wistar rats were randomized and transplanted with syngeneic left lung or received the sham surgery. The recipients were instilled with saline or budesonide immediately after reperfusion. The mean arterial pressure (MAP), blood gas, and lung histology were analyzed. The ratios of wet to dry lung weights, the levels of total proteins, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10, and neutrophil elastase in bronchoalveolar lavage fluid (BALF) were measured. The levels of malondialdehyde (MDA), myeloperoxidase (MPO), and xanthine oxidase (XO) in the lung, and the levels of plasma lymphocyte function-associated antigen (LFA)-1 and P-selectin were determined.

RESULTS

Compared with the saline group, treatment with budesonide significantly increased blood PaO₂, but reduced PaCO₂, and mitigated lung damages after reperfusion, the levels of BALF proteins, and the ratios of wet to dry lung weights in rats. Furthermore, treatment with budesonide significantly decreased the levels of MDA, MPO, and XO in the lung and the levels of TNF-α, IL-1β, IL-6, and neutrophil elastase, but increased IL-10 in the BALF, accompanied by significantly reduced levels of serum P-selectin and LFA-1 in rats.

CONCLUSIONS

Budesonide effectively mitigated LIRI and ameliorated the lung function by attenuating oxidative stress and inflammation following syngeneic lung transplantation.

Protective effect of glutamine on the main and adjacent organs damaged by ischemia-reperfusion in rats

Intestinal ischemia and reperfusion (I/R) causes cellular and tissue damage to the intestine and remote organs such as the liver. Increased production of ROS and nitric oxide and dysregulation of cytoprotective enzymes may be involved in intestinal I/R. The aim was to evaluate the protective effects of glutamine on the intestine and liver of rats with intestinal I/R injury. Twenty male Wistar rats (300 g) were divided into four groups: sham-operated (SO), glutamine + SO (G + SO), I/R, and glutamine + I/R (G + I/R). Occlusion of the SMA for 30 min was followed by 15-min reperfusion. Glutamine (25 mg/kg/day) was administered once daily 24 and 48 h before I/R induction. Blood and tissue of were collected for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, histopathological analysis, immunohistochemistry of IL-1β and TNF-α, thiobarbituric acid reactive substance (TBARS) and nitric oxide, Nrf2/keap1, superoxide dismutase (SOD), NADPH quinone oxidoreductase1 (NQO1), inducible nitric oxide synthase (iNOS), heat shock protein (HSP70), glucose-regulated protein 78 (GRP78), and activating transcription factor 6 (ATF-6) by western blot. Statistic analysis by ANOVA-Student-Newman-Keuls test (mean ± SE) significantly was p < 0.05. Tissue damage, AST, ALT, IL-1β, TNF-α, TBARS, NO, Keap1, iNOS, GRP78, and ATF-6 expression were significantly lower in the G + I/R group as compared to the I/R group. Expression of Nrf2, SOD, NQO1, and HSP70, was significantly higher in the G + I/R group as compared to I/R group. Pre-treatment with glutamine provided protection against oxidative damage in the intestine and liver in an experimental model of intestinal I/R.

Over-expression of heat shock protein 70 protects mice against lung ischemia/reperfusion injury through SIRT1/AMPK/eNOS pathway

Lung ischemia/reperfusion injury (LIRI) usually occurs during in lung transplantation and extracorporeal circulation operation and may develop into pulmonary infections, acute rejection and bronchiolitis obliterans syndrome. Recent studies have discovered the protective effect of heat shock protein 70 (HSP70) on various types of injuries. In the present study, we firstly explore the role of over-expressed HSP70 on the protection against LIRI. Lung Wet/Dry (W/D) ratio, biomarkers in the bronchoalveolar lavage fluid (BALF), lung histological changes and apoptosis markers, oxidative products and proinflammatory cytokines in the lung tissues were analyzed. Next, the expression of eNOS, SIRT1 and AMPK were measured. Finally, the changes of the lung W/D ratio and biomarkers in the BALF using the inhibitors of SIRT1/AMPK/eNOS pathway were evaluated. Mice exposed to LIRI procedure had significant increases in lung W/D ratio and biomarkers (protein level, LDH level, leukocytes and total cells) in BALF. LIRI also caused histological injury, demonstrated by hemorrhage, alveolar septal thickening and fibrin deposition. Apoptosis, oxidative products and proinflammatory cytokines in lung tissue were also induced by LIRI. The over-expression of HSP70 antagonized the impacts of LIRI by attenuating these parameters. It significantly increased the expression of eNOS, SIRT1 and AMPK, while the inhibition of SIRT1 and AMPK deactivated the eNOS expression. The lung W/D ratio and biomarkers in BALF were increased while mice were given inhibitors of eNOS, SIRT1 and AMPK. We concluded that over-expression of HSP70 had protective effect on LIRI and HSP70 might be involved in the protection through a SIRT1/AMPK/eNOS pathway.

The protective effect of infliximab against carbon tetrachloride-induced acute lung injury

OBJECTIVES

Carbon tetrachloride (CCl4) causes pulmonary toxicity. Infliximab (Ib) is a potent inhibitor of tumor necrosis factor-alpha (TNF-α). We aimed to investigate whether Ib has a protective effect on CCl4 induced lung injury.

MATERIALS AND METHODS

Rats were divided into control, CCl4, and CCl4+Ib groups. A single dose of 2 ml/kg CCI4 was administered to CCI4 group and a single dose of 7 mg/kg Ib was given to CCl4+Ib group 24 hr before applying CCI4.

RESULTS

TNF-α, malondialdehyde (MDA), nitric oxide (NO) and caspase-3 levels of the CCl4 group were markedly higher than both the control and CCl4+Ib groups. The CCI4+Ib group had lower histopathological injury than the CCl4 group.

CONCLUSION

Ib as a strong TNF-α blocker decreases the production of proinflammatory cytokines, MDA, and oxidative stress leading to a protective effect against CCl4 induced lung tissue injury.

Mesenteric lymph duct drainage attenuates acute lung injury in rats with severe intraperitoneal infection

The purpose of this study is to investigate the hypothesis that the mesenteric lymphatic system plays an important role in acute lung injury in a rat model induced by severe intraperitoneal infection. Male Wistar rats weighing 250∼300 g were randomly divided into 3 groups and subjected to sham operation, intraperitoneal infection, or mesenteric lymphatic drainage. The activity of diamine oxidase (DAO) and myeloperoxidase (MPO) were measured by enzymatic assay. The endotoxin levels in plasma, lymph, and bronchoalveolar lavage fluid (BALF) were evaluated using the limulus amoebocyte lysate reagent. The cytokines, adhesion factors, chemokines, and inflammatory factors were detected by ELISA. TLR-4, NF-kB, and IRAK-4 were analyzed by Western blotting. Compared with sham-operated rats, rats with intraperitoneal infection had increased MPO and decreased DAO activity in intestinal tissues. Mesenteric lymph drainage reduced the alterations in MPO and DAO activity induced by intraperitoneal infection. The MPO activity in pulmonary tissue and the permeability of pulmonary blood vessels were also increased, which were partially reversed by mesenteric lymph drainage. The endotoxin levels in lymphatic fluid and alveolar perfusion fluid were elevated after intraperitoneal infection but decreased to control levels after lymph drainage. No alterations in the levels of plasma endotoxin were observed. The number of neutrophils was increased in BALF and lymph in the infected rats, and was also reduced after drainage. Lymph drainage also decreased the levels of inflammatory cytokines, chemokines, and adhesion factors in the plasma, lymph, and BALF, as well as the levels of TLR-4, NF-kB, and IRAK-4 in pulmonary and intestinal tissues. The mesenteric lymphatic system is the main pathway involved in early lung injury caused by severe intraperitoneal infection, in which activation of the TLR-4 signal pathway may play a role.

Protective effects of dexamethasone on early acute lung injury induced by oleic acid in rats

OBJECTIVE

Whether alveolar edema could be cleared by alveolar epithelial is a key to the treatment and prognosis of ALI (acute lung injury). In this study, oleic acid(OA)-induced ALI model was established, the expression of α1 Na(+)/K(+)-ATPase (NKA) and β1 Na(+)/K(+)-ATPase were performed in vivo to investigate the mechanism of alveolar fluid clearance (AFC) in ALI and the effect of early low doses of dexamethasone on alveolar fluid clearance.

METHODS

In this study, Male rats were challenged by OA with or without dexamethasone (1 mg/kg, iv) post-treatment. Lung histopathology, blood gas, pulmonary vascular permeability, BALF IL-6, MPO and NKA activity of lung were examined. α1NKA and β1NKA mRNA and protein expression were detected.

RESULTS

The results indicated that compared with sham operated group, NKA activity, mRNA and protein expression of α1NKA and β1NKA were decreased in OA treated group, while wet/dry ratio, lung index, IL-6, and MPO activity were increased significantly. Pulmonary edema was obviously seen under light microscope. Those indexes were improved in dexamethasone treated group compared to OA treated group.

CONCLUSION

The expression of NKA to decline for the lung injury is one important mechanism of pulmonary edema. Early low dose of dexamethasone treatment could suppress the expression of inflammatory mediators, improved lung epithelial-endothelial barrier permeability, increased the expressions of α1 NKA and β1 NKA mRNA, α1 NKA and β1 NKA protein level, stimulated NKA activity and decreased pulmonary edema. In conclusion, these observations suggest that early low dose of dexamethasone treatment has a protective effect on OA induced ALI.

Ischemia postconditioning preventing lung ischemia-reperfusion injury

OBJECTIVE

This study evaluates the inhibitory effect of IPO against ischemia reperfusion (I/R) induced lung injury in rats.

METHODS

Anesthetized and mechanically ventilated adult Sprague-Dawley rats were randomly assigned to one of the following groups (n=12 each): the sham operated control group, the ischemia-reperfusion (IR) group (30min of left-lung ischemia and 24h of reperfusion), the IPO group (three successive cycles of 30-s reperfusion per 30-s occlusion before restoring full perfusion), and the dexamethasone plus IPO group (rats were injected with dexamethasone (3mg/kg·day(-1)) 10min prior to the experiment and the rest of the procedures were the same as the IPO group). Lung injury was assessed by wet-to-dry lung weight ratio and tissue apoptosis and biochemical changes.

RESULTS

Lung ischemia-reperfusion increased lung MDA production, serum proinflammatory cytokine count, and MPO activity and reduced antioxidant enzyme activities (all p<0.05 I/R versus sham), accompanied with a compensatory increase in caspase-3, bax, Fas, FasL proteins and a decrease in Bcl-2 protein. Plasma levels of TNF-α, IL-6, and IL-1β were increased in the I/R group (all p<0.05 versus sham). IPO attenuated or prevented all the above changes. Treatment with dexamethasone enhanced all the protective effects of postconditioning.

CONCLUSION

Postconditioning obviously inhibits I/R induced lung injury by its antioxidant, anti-inflammatory and anti-apoptosis activities.

The role of hybridization in improving the immune response and thermal tolerance of abalone

Recently, frequent death of cultured abalone drew our attention to the stress tolerance of abalone. Hybridization is an effective way of genetic improvement in aquaculture, which can introduce improved traits to the hybrids. In this study, we challenged the hybrids between Haliotis discus hannai and Haliotis gigantea, and their parents with bacteria (vibrio harveyi, vibrio alginolyticus and vibrio parahemolyticus), then held them at 20 °C and 28 °C, survival rates of the parental populations and hybrid populations were recorded. Then we tested the immune responses and thermal-induced responses of the four populations at different temperatures. Total hemocyte count (THC), respiratory burst, superoxide dismutase activity (SOD), acid phosphatase activity (ACP), alkaline phosphatase activity (AKP), myeloperoxidase activity (MPO), and HSP70 expression were determined on day 1 and day 7 of the temperature exposure. Results showed higher survival rates of the hybrids than their parents against bacteria challenge. For immune parameters, THCs were evaluated at 28 °C, while increased THC was also observed in H. discus hannai ♀ × H. gigantea ♂ (DG) and H. discus hannai ♀ × H. discus hannai ♂ (DD) at 12 °C (day 7); at 28 °C, respiratory burst was activated (day 1 and 7), while SOD activity first rose then fell over 7-days exposure; AKP activity was elevated at 12 °C and 28 °C (day 1), most notably in DG, and an increased level of ACP was observed in DG at 28 °C (day 7); MPO activity was suppressed at 12 °C and 28 °C on day 1, but recovered on day 7. For HSP70, increased HSP70 levels were observed in all populations at 28 °C (day 1), and DD got the lowest HSP70 level after 7-days exposure at 28 °C. Overall, the results suggest that temperature changes could significantly affect the physiological status of abalone, and hybrids may be more resistant to disease and thermal stresses than their parents.

Pretreatment with mineralocorticoid receptor blocker reduces intestinal injury induced by ischemia and reperfusion: involvement of inhibition of inflammatory response, oxidative stress, nuclear factor κB, and inducible nitric oxide synthase

BACKGROUND

Spironolactone (Sp), a mineralocorticoid receptor antagonist, protects against the ischemia reperfusion (IR) injury of retina, kidney, heart, and brain. We aimed to investigate the effects of Sp on intestinal IR injury.

METHODS

Male Wistar rats were randomly divided into: (1) a sham control group; (2) an IR control group, subjected to 30 min ischemia and 3 h reperfusion; (3) a group treated with Sp (20 mg/kg) for 3 d before the IR; and (4) a sham-operated control group treated with Sp (20 mg/kg). After the reperfusion, blood and intestinal tissue samples were collected to evaluate histopathologic state, neutrophil infiltration (by measuring myeloperoxidase activity), levels of the cytokines (tumor necrosis factor α, interleukin 1α [IL-1α], interferon γ, monocyte chemotactic protein-1, granulocyte macrophage-colony stimulating factor, and IL-4), malondialdehyde (MDA) and reduced glutathione contents, and immunohistochemical expressions of nuclear factor κB, inducible nitric oxide synthase (iNOS), and caspase-3.

RESULTS

MDA content, myeloperoxidase activity, and plasma levels of tumor necrosis factor α, IL-1α, and monocyte chemotactic protein-1 were all elevated in IR, indicating the oxidative stress and local and systemic inflammatory response. Sp administration markedly reduced the MDA content and the cytokine levels. The pretreatment alleviated intestinal injury, neutrophil infiltration, and the expressions of caspase-3, iNOS, and NFκB.

CONCLUSIONS

The results implicate that Sp may have a strong protective effect against the intestinal IR injury. The effect can be mediated via suppression of both systemic inflammatory response and apoptosis through amelioration of oxidative stress and generation of proinflammatory cytokines, iNOS, caspase-3, and nuclear factor κB. Therefore, mineralocorticoid receptor antagonism might be of potential therapeutic benefit in cases of intestinal IR damage.

Osthole prevents intestinal ischemia-reperfusion-induced lung injury in a rodent model

BACKGROUND

Intestinal ischemia-reperfusion (II/R) is associated with high morbidity and mortality. The aim of this study was to investigate the effects of osthole on lung injury and mortality induced by II/R.

METHODS

A rat model of II/R was induced by clamping the superior mesenteric artery for 90 min followed by reperfusion for 240 min. Osthole was administrated intraperitoneally at 30 min before intestinal ischemia (10 or 50 mg/kg). The survival rate and mean arterial pressure were observed. Blood samples were obtained for blood gas analyses. Lung injury was assessed by the histopathologic changes (hematoxylin and eosin staining), lung wet-to-dry weight ratio, and pulmonary permeability index. The levels of reactive oxygen species, malondialdehyde, interleukin 6, and tumor necrosis factor α, as well as the activities of superoxide dismutase and myeloperoxidase in lung were measured.

RESULTS

The survival rate, ratio of arterial oxygen tension to fraction of inspired oxygen, and mean arterial pressure decreased significantly after II/R. Results also indicated that II/R-induced severe lung injury evidenced by increase in pathologic scores, lung wet-to-dry weight ratio, and pulmonary permeability index, which was accompanied by increases in the levels of pulmonary reactive oxygen species, malondialdehyde, interleukin 6, tumor necrosis factor α, and the pulmonary myeloperoxidase activity and a decrease in superoxide dismutase activity. Osthole could significantly ameliorate lung injury and improve the previously mentioned variables.

CONCLUSIONS

These findings indicated that osthole could attenuate the lung injury induced by II/R in rats, at least in part, by inhibiting inflammatory response and oxidative stress.

Radioprotective agents for the prevention of side effects induced by radioiodine-131 therapy

Radioiodine 131 (131I) has been used worldwide for the ablation of remnant thyroidal tissue after surgery or as the first-line treatment for Graves’ disease. Although the use of 131I is becoming increasingly prevalent, there is evidence suggesting that this treatment is associated with side effects such as salivary gland dysfunction and an increased risk of leukemia. This article aims to review the potential use of radioprotective agents and the side effects induced by 131I therapy. Several synthetic and natural compounds have been investigated in preclinical and clinical studies. The protective agents reduced the toxicity of 131I, mainly in the salivary glands, and mitigated the genetic damage through different mechanisms. There are limited clinical studies evaluating the use of radioprotective agents in patients undergoing radioiodine therapy. However, lemon candies, lemon juice and sugarless chewing gum have been proposed to be beneficial for minimizing the side effects of radioiodine within the salivary glands.

Limb remote ischemic preconditioning for intestinal and pulmonary protection during elective open infrarenal abdominal aortic aneurysm repair: a randomized controlled trial

BACKGROUND

Remote ischemic preconditioning (RIPC) may confer the cytoprotection in critical organs. The authors hypothesized that limb RIPC would reduce intestinal and pulmonary injury in patients undergoing open infrarenal abdominal aortic aneurysm repair.

METHODS

In this single-center, prospective, double-blinded, randomized, parallel-controlled trial, 62 patients undergoing elective open infrarenal abdominal aortic aneurysm repair were randomly assigned in a 1:1 ratio by computerized block randomization to receive limb RIPC or conventional abdominal aortic aneurysm repair (control). Three cycles of 5-min ischemia/5-min reperfusion induced by a blood pressure cuff placed on the left upper arm served as RIPC stimulus. The primary endpoint was arterial-alveolar oxygen tension ratio. The secondary endpoints mainly included the intestinal injury markers (serum intestinal fatty acid-binding protein, endotoxin levels, and diamine oxidase activity), the markers of oxidative stress and systemic inflammatory response, and the scores of the severity of intestinal and pulmonary injury.

RESULTS

In limb RIPC group, a/A ratio was significantly higher than that in control group at 8, 12, and 24 h after cross-clamp release (66 ± 4 vs. 45 ± 4, P = 0.003; 60 ± 6 vs. 37 ± 4, P = 0.002; and 60 ± 5 vs. 47 ± 6, P = 0.039, respectively). All biomarkers reflecting intestinal injury increased over time, and there was significant differences between limb RIPC and control group (P < 0.001). The severity of intestinal and pulmonary injury was decreased by limb RIPC (P = 0.014 and P = 0.001, respectively).

CONCLUSIONS

Limb RIPC attenuates intestinal and pulmonary injury in patients undergoing elective open infrarenal abdominal aortic aneurysm repair without any potential risk.

Ginkgo biloba leaves extract (EGb 761) attenuates lipopolysaccharide-induced acute lung injury via inhibition of oxidative stress and NF-κB-dependent matrix metalloproteinase-9 pathway

Acute lung injury (ALI) presents high mortality and morbidity clinically and by far no effective preventive strategy has been established. Extract of Ginkgo biloba leaves, EGb 761, is a complex mixture that possesses several clinical beneficial effects such as anti-oxidation, anti-inflammation, anti-tumor, and cardioprotective property. With EGb 761 pretreatment, both lipopolysaccharide (LPS)-induced protein leakage and neutrophil infiltration, and LPS-induced inflammatory responses including increased myeloperoxidase (MPO) activity, lipid peroxidation, and metalloproteinase (MMP)-9 activity, were inhibited; LPS-suppressed activation of antioxidative enzymes (AOE) were reversed; and not only the phosphorylation of NF-κB but also the degradation of its inhibitor, IκB, were suppressed. These results suggested that the protection mechanism of EGb 761 is by inhibition of NFκB activation, possibly via the up-regulation of antioxidative enzymes. More studies are needed to further evaluate whether EGb 761 is a suitable candidate as an effective dietary strategy to reduce the incidence of endotoxin-induced ALI.

Intestinal ischemia/reperfusion enhances microglial activation and induces cerebral injury and memory dysfunction in rats

OBJECTIVE

The mortality of critically ill patients associated with intestinal ischemia/reperfusion remains very high, which results from multiorgan dysfunction or failure due to intestinal injury induced by intestinal ischemia/reperfusion. This study was carried out to investigate whether intestinal ischemia/reperfusion can cause cerebral injury and concomitant memory dysfunction, and explore the potential mechanisms.

DESIGN

Prospective, controlled, and randomized animal study.

SETTING

University research laboratory.

SUBJECTS

Male, adult Sprague-Dawley rats (weighing 250-300 g).

INTERVENTIONS

Intestinal ischemia/reperfusion was established by clamping the superior mesenteric artery for 90 mins followed by different reperfusion durations (2, 6, 12, 24, or 48 hrs). The sham surgical preparation including isolation of the superior mesenteric artery without occlusion was performed as control.

MEASUREMENTS AND MAIN RESULTS

In comparison with sham control, intestinal ischemia/reperfusion caused severe intestinal injury, accompanied by notable cerebral damage evidenced by increased wet-to-dry brain weight ratio reflecting brain edema and neuronal cell apoptosis manifested by increased apoptotic cell number and cleaved caspase-3 protein expressions. All these changes were concomitant with reduced survival rates as well as impaired memory function determined by Morris water maze test at 24 and 48 hrs after reperfusion. In addition, intestinal ischemia/reperfusion resulted in significant increases in the levels of tumor necrosis factor-α and interleukin-6 both in the serum and in cortices and hippocampal Cornu Ammonis area 1 regions, concomitant with the activation of microglia, a key cellular mediator involved in neuroinflammation and neurodegeneration, which was evidenced by increased protein expressions of ionized calcium binding adaptor molecule 1. Furthermore, the releases of reactive oxygen species evidenced by increased malondialdehyde levels and decreased superoxide dismutase activities in cortices and hippocampal Cornu Ammonis area 1 regions were found after reperfusion.

CONCLUSIONS

These findings indicate that intestinal ischemia/reperfusion-induced intestinal injury can lead to cerebral damage and memory dysfunction partly via microglia activation which further facilitates oxidative injury, inflammatory response, and neuronal cell apoptosis.

The protective effect of Ginkgo biloba extract against experimental cisplatin ototoxicity: animal research using distortion product otoacoustic emissions

BACKGROUND

Cisplatin, an effective therapeutic agent for various human cancers, has dose-limiting side effects of ototoxicity and nephrotoxicity. Cisplatin ototoxicity is thought to result from increased amounts of toxic free radicals or cell membrane changes leading to increased intracellular calcium content. Ginkgo biloba extract prevents lipid peroxidation, decreases intracellular free oxygen radical levels, regulates the cell membrane calcium transport mechanism and prevents cell death. This study aimed to investigate the protective effect of Ginkgo biloba extract against cisplatin-induced ototoxicity in rats.

METHODS

Twenty Wistar albino rats with normal hearing (confirmed by distortion product otoacoustic emission testing prior to cisplatin application) were randomly allocated to two groups. Both groups received a single intraperitoneal dose of cisplatin (12 mg/kg). Group two also received daily intraperitoneal doses of Ginkgo biloba extract (100 mg/kg) for 10 days. Distortion product otoacoustic emission measurements were repeated on days 10 and 17 and signal-to-noise ratios were compared.

RESULTS

Compared with group one, group two had significantly better distortion product otoacoustic emission results at 3, 4, 6 and 8 kHz on days 10 and 17.

CONCLUSION

These findings suggest that Ginkgo biloba extract protects the inner ear against cisplatin-induced ototoxicity.

Protective effect of curcumin on acute lung injury induced by intestinal ischaemia/reperfusion

The aim of this study is to evaluate the role of curcumin on acute lung injury induced by intestinal ischaemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into 3 groups: sham, I/R, and I/R + curcumin; each group contains 10 animals. Sham group animals underwent laparotomy without I/R injury. After I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In the curcumin group, 3 days before I/R, curcumin (100 mg/kg) was administered by gastric gavage. All animals were killed at the end of reperfusion and lung tissue samples were obtained for biochemical and histopathological investigation in all groups. To date, no more biochemical and histopathological changes on intestinal I/R injury in rats by curcumin treatment have been reported. Curcumin treatment significantly decreased the elevated tissue malondialdehyde levels and increased reduced superoxide dismutase, and glutathione peroxidase enzyme activities in lung tissue samples. Intestinal I/R caused severe histopathological injury including oedema, haemorrhage, increased thickness of the alveolar wall, and infiltration of inflammatory cells into alveolar spaces. Curcumin treatment significantly attenuated the severity of intestinal I/R injury. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase and increase in the expression of surfactant protein D in lung tissue of acute lung injury induced by intestinal I/R with curcumin therapy. It was concluded that curcumin treatment may have beneficial effects in acute lung injury, and therefore has potential for clinical use.

The protective effects of Ginkgo biloba extract (EGb-761) on radiation-induced dermatitis: an experimental study

BACKGROUND

Irradiation of the skin induces production of free radicals, resulting in oxidative stress. EGb-761, an extract from the leaves of the Ginkgo biloba tree, has been reported to be an effective exogenous antioxidant based on its free-radical scavenger properties.

AIM

To investigate the protective effect of G. biloba extract (EGb-761) on radiation-induced dermatitis in rats.

METHODS

Forty male Wistar rats were divided equally into four groups: group 1 received sham radiotherapy (RT) without EGb-761, group 2 received sham RT with EGb-761, group 3 received RT without EGb-761, and group 4 received RT with EGb-761. Levels of malondialdehyde (MDA), nitric oxide (NOx) and glutathione (GSH) were measured. Dermatitis was assessed with a semiquantitative dermatitis item score. The intensity of staining and diffusion of expression for proliferating cellular nuclear antigen (PCNA) and transforming growth factor (TGF)-β3 were also evaluated.

RESULTS

The enhanced oxidative stress seen after RT was markedly diminished when EGb-761 was administered with RT; significantly lower mean MDA (P < 0.005) and higher mean GSH (P < 0.001) levels were seen in group 4 compared with group 3. Although there was a decrease in NOx levels, this was not significant. All (100%) of the animals in group 3 developed dermatitis, whereas only 13% of the animals in group 4 did so (P < 0.0001). There was a significant difference between group 1 and group 3 in PCNA and TGF-β3 staining (P < 0.05), whereas no difference was seen between groups 3 and 4; however, the intensity of staining and diffusion of expression were lower in group 4 than in group 3.

CONCLUSIONS

Prophylactic administration of EGb-761 seems to have a protective effect against radiation-induced dermatitis.

Protective effects of Ginkgo biloba extract in rats with hypoxia/reoxygenation-induced intestinal injury

BACKGROUND

The purpose of this study is to investigate the protective effects of Ginkgo biloba extract (EGb 761) in rat pups with hypoxia/reoxygenation (H/R)-induced bowel injury.

METHODS

One-day-old Wistar albino rat pups (n = 21) were randomly divided into 3 groups: group 1 (control, untreated and not exposed to H/R, n = 7), group 2 (untreated but exposed to H/R, n = 7), and group 3 (EGb 761 + H/R, n = 7). Ginkgo biloba extract was administered (100 mg/kg per day, subcutaneously) to group 3 for 3 days. On the fourth day, all animals except controls were exposed to H/R and were killed 6 hours after H/R. Histopathologic injury scores (HIS), malondialdehyde, glutathione (GSH), GSH-peroxidase (Px) activities, and nitric oxide (NO) levels were measured on intestinal samples.

RESULTS

Although the control group had normal HIS, group 2 had grade 3 HIS. In contrast, group 3 had minimal HIS, and these results were significantly better than those of group 2 (P < .001). Malondialdehyde and NO levels of group 3 were significantly lower than those of group 2 (P < .01). Glutathione and GSH-Px activities of group 1 were higher than those of groups 2 and 3 (P < .05). However, there were no significant differences for GSH and GSH-Px activities between groups 2 and 3.

CONCLUSIONS

This study showed that hypoxia and NO contributed to the pathogenesis of H/R-induced intestinal injury and that prophylactically administered EGb 761 had a protective effect on bowel injury.

Modulation of nitrosative/oxidative stress in the lung of hyperglycemic rabbits by two antidiabetics, pioglitazone and repaglinide

The lungs are involved in diabetes in the cause of the complex phenomena diabetes generates. In the present study, hyperglycemia inhibited pulmonary antioxidants, including superoxide dismutase, catalase, glutathione peroxidase, and glutathione. These effects were accompanied by significant elevation of lipid peroxidation, total nitrites, and nitrotyrosine levels. The study investigated the effects of 2 oral antidiabetics, pioglitazone and repaglinide, on the mentioned parameters. It is concluded that pioglitazone exerts protective effect in the lung by inhibiting nitrosative stress and normalizing the nitrites and nitrotyrosine levels. Administration of repaglinide prevents oxidative and, to a smaller extent, nitrosative changes.

Intestinal ischaemia/reperfusion upregulates beta-defensin-2 expression and causes acute lung injury in the rat

OBJECTIVE

Human beta-defensin-2 (BD-2) is a positive ion antimicrobial peptide. We investigated the effects of intestinal ischaemia/reperfusion (II/R) on rat BD-2 mRNA and protein expressions in rat lung to address the potential role of BD-2 in acute lung injury (ALI) induced by II/R.

METHODS

Rats were randomly divided into two groups (n=36 each). (i) Sham control and (ii) II/R group (1h superior mesenteric artery clamping, followed by reperfusion of different durations). In II/R group, 6 animals were sacrificed at 0min, 15min, 30min, 60min, 3h and 6h after reperfusion, and serum, lung tissue and bronchoalveolar lavage fluid were harvested. Samples were taken at the corresponding time points in the sham group. Lung histological changes were observed under microscope and the pulmonary permeability index (PPI) was calculated. The lung tissue levels of TNFalpha were detected by ELISA. BD-2 mRNA and protein expressions were examined by RT-PCR and western blotting techniques, respectively.

RESULTS

ALI induced by II/R was confirmed by pathological examination and significantly increased PPI (P<0.05 or 0.01). II/R significantly increased the lung TNFalpha levels and upregulated the expressions of BD-2 mRNA and protein expressions (P<0.05 or 0.01). BD-2 mRNA expression was significantly positively correlated to the lung TNFalpha level (r=0.823, P<0.01) and negatively correlated to PPI (r=-0.615, P<0.05).

CONCLUSION

II/R can upregulate BD-2 mRNA and protein expressions in rat lung. BD-2 could be an innate protective factor against II/R-induced lung injury.

Panax notoginseng saponins attenuate acute lung injury induced by intestinal ischaemia/reperfusion in rats

BACKGROUND AND OBJECTIVE

Acute lung injury remains a challenge for both clinicians and scientists. The effects of Panax notoginseng saponins (PNS) on acute lung injury induced by intestinal ischaemia/reperfusion (II/R) were studied in rats.

METHODS

Forty-eight Wistar rats were randomly assigned to four groups: (1) a sham-operated group that received laparotomy without II/R (n= 12); (2) a sham + PNS group, which was identical to group 1 except for PNS treatment (n= 12); (3) an II/R group that had 1 h of intestinal ischaemia followed by 3 h of reperfusion (n= 12); and (4) an II/R + PNS group that received 100 mg/kg of PNS, i.v., 15 min before reperfusion (n= 12). The effects of PNS administration on lung tissue histology, activities of oxidant and antioxidant enzymes, levels of malondialdehyde, nitric oxide and inducible nitric oxide synthase activity were examined. Levels of surfactant protein B, cell numbers in BAL fluid and plasma levels of pro-inflammatory cytokines were also examined.

RESULTS

Compared with the II/R group, pulmonary parenchymal damage, activities of oxidant enzymes, levels of malondialdehyde and nitric oxide, inducible nitric oxide synthase activity in lung tissue, and plasma levels of pro-inflammatory cytokines were significantly reduced by PNS treatment. In addition, the decreases in antioxidant enzyme activities were prevented in the II/R + PNS group. Total leukocyte and neutrophil counts were significantly decreased by PNS treatment. The decline in surfactant protein B levels in BAL fluid was reduced in the II/R + PNS group compared with the II/R group.

CONCLUSIONS

Administration of PNS before reperfusion injury alleviates acute lung injury induced by II/R, and this is attributable to the antioxidant and anti-inflammatory effects of PNS.

NAC is associated with additional alleviation of lung injury induced by invasive pulmonary aspergillosis in a neutropenic model

AIM

Neutropenic individuals are at high risk for invasive pulmonary aspergillosis (IPA), a life-threatening infection. To evaluate the therapeutic potential of antioxidants, IPA was induced in neutropenic mice and the effect of N-acetyl-l-cysteine (NAC) on oxidative stress levels and lung injury was analyzed.

METHODS

Mice were pretreated with three daily intraperitoneal injections of 150 mg/kg cyclophosphamide, followed by intratracheal inoculation with 4.5x10(6) conidia of Aspergillus fumigatus. The infected mice were then randomly assigned to an amphotericin B (AMB) group, an AMB plus NAC group, or an untreated control (C) group. In each group, the duration of treatment was 24, 48, or 72 h, and activities such as appearance, feeding, and dermal temperature were observed throughout the experiment. Sera and lung tissues were collected and analyzed by quantitative enzyme-linked immunosorbent assay (ELISA) for total protein, superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-alpha), and interleukin-10 (IL-10) levels. The wet/dry weight ratio of the lung was also calculated and lung sections were stained with hematoxylin-eosin for pathological examination and with methenamine silver stain for fungus detection.

RESULTS

Compared with the mice untreated with NAC, mice in the AMB plus NAC group had increased SOD and reduced MDA levels both systemically and locally at 24, 48, and 72 h after inoculation with conidia. NAC treatment also decreased the pulmonary protein content at 48 and 72 h and the lung wet/dry weight ratio at 24 and 48 h. Additionally, NAC enhanced pulmonary production of TNF-alpha and IL-10 at 24 h and 48 h.

CONCLUSION

In combination with antifungal therapy, NAC treatment can alleviate oxidative stress and lung injury associated with IPA in neutropenic mice.Acta Pharmacologica Sinica (2009) 30: 980-986; doi: 10.1038/aps.2009.83.

Ginkgo biloba extract prevents glucose-induced accumulation of ECM in rat mesangial cells

Pathological remodeling characterized by extracellular matrix (ECM) accumulation contributes to diabetic nephropathy (DN). This study evaluated the effects of Ginkgo biloba extract (GbE) on the metabolism of the ECM in rat mesangial cells cultured in hyperglycemic conditions. The cultured mesangial cells in high glucose conditions were allotted into six groups: normal control group, high glucose group, low concentration of GbE group, moderate concentration of GbE group, high concentration of GbE group, and captopril group. In the presence of high glucose, the levels of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and extracellular matrix metalloproteinase inducer (EMMPRIN) were decreased significantly, and the levels of tissue inhibitor of metalloproteinase-2 (TIMP-2), tissue inhibitor of metalloproteinase-1 (TIMP-1) and plasminogen activator inhibitor-1 (PAI-1) were increased significantly. These changes were reversed by GbE. GbE lowered the levels of transforming growth factor-beta(1) (TGF-beta(1)), insulin-like growth factor-1 (IGF-1) and connective tissue growth factor (CTGF) of the high glucose group. Furthermore, GbE also decreased the expressions of collagen IV and laminin of the high glucose group. In summary, the results suggest that GbE postpones the extracellular matrix accumulation by inhibiting the synthesis of ECM and promoting the degradation of ECM, and therefore, is a potential drug for the prevention and treatment of DN.

Pitavastatin prevents intestinal ischemia/reperfusion-induced bacterial translocation and lung injury in atherosclerotic rats with hypoadiponectinemia

BACKGROUND

Atherosclerosis with hypoadiponectinemia can be further aggravated by intestinal ischemia/reperfusion (II/R)-induced injuries, such as bacterial translocation and lung injury. We investigated the effect of statin administration on the risk of II/R-induced injury in atherosclerotic rats with hypoadiponectinemia.

METHODS

Wistar rats were divided into 4 groups: (1) the Normal group (normal diet), (2) the Chol group (2% high cholesterol diet), (3) the St-1w group, and (4) the St-2w group (Chol group plus pitavastatin administration for 1 or 2 weeks, respectively). The serum concentrations of lipids and adiponectin were measured preoperatively. After midline laparotomy (time, T0), the superior mesenteric artery was occluded with a microvascular clamp for 30 min, followed by 360 min of reperfusion (T1). Intestinal and lung nitric oxide (NO) concentrations were measured. Intestinal injury was assessed by microcirculatory flow, histology, and permeability. Bacterial translocation was assessed by analysis of serum peptidoglycan concentration. Lung injury was assessed by histologic examination, pulmonary permeability index, and wet/dry lung weight ratio.

RESULTS

The 2-week administration of statins with high-cholesterol feeding (St-2w group) improved hypoadiponectinemia to levels similar to those of the Normal group. Intestinal and lung NO concentrations were significantly lower at T1 in the Normal and St-2w groups than in the Chol group. Statin administration improved poor recovery of intestinal microcirculatory flow in the Chol group. At T1, intestinal and lung injuries were significantly aggravated and serum peptidoglycan concentration was significantly elevated in the Chol group compared with the Normal and St-2w groups. The 1-week administration of statins had no significant influence on serum adiponectin levels, tissue NO concentration, or tissue injury.

CONCLUSION

Administration of pitavastatin reduces the risk of II/R-induced injury in atherosclerotic rats with hypoadiponectinemia by improving hypoadiponectinemia and inhibiting inducible NO synthase-produced NO. Furthermore, preoperative improvement of hypoadiponectinemia may be important as an index of the protective effect of pitavastatin for II/R-induced injury in atherosclerotic rats with hypoadiponectinemia.

Hydrogen-rich saline reduces lung injury induced by intestinal ischemia/reperfusion in rats

OBJECTIVE

Hydrogen has been reported to selectively reduce the hydroxyl radical, the most cytotoxic of reactive oxygen species. In this study we investigated the effects of hydrogen-rich saline on the prevention of lung injury induced by intestinal ischemia/reperfusion (I/R) in rats.

METHODS

Male Sprague-Dawley rats (n=30, 200-220g) were divided randomly into three experimental groups: sham operated, intestinal I/R plus saline treatment (5ml/kg, i.v.), and intestinal I/R plus hydrogen-rich saline treatment (5ml/kg, i.v.) groups. Intestinal I/R was produced by 90min of intestinal ischemia followed by a 4h of reperfusion.

RESULTS

Hydrogen-rich saline treatment decreased the neutrophil infiltration, the lipid membrane peroxidation, NF-kappaB activation and the pro-inflammatory cytokine interleukin IL-1beta and TNF-alpha in the lung tissues compared with those in saline-treated rat.

CONCLUSION

Hydrogen-rich saline attenuates lung injury induced by intestinal I/R.

Immediate postconditioning during reperfusion attenuates intestinal injury

OBJECTIVE

To test the hypothesis that immediate but not delayed ischemic postconditioning (IPo) during reperfusion attenuates intestinal injury, and that ischemic preconditioning (IPC) and IPo may confer synergy in intestinal protection.

DESIGN AND SETTING

Prospective laboratory animal study with concurrent control.

SUBJECTS

Adult Sprague-Dawley rats.

INTERVENTIONS

Intestinal ischemia/reperfusion (II/R) injury in rats was produced by clamping superior mesenteric artery for 60 min followed by 60 min reperfusion; IPC was elicited by 10 min ischemia and 10 min reperfusion before index ischemia; IPo was performed by three cycles of 30 s reperfusion and 30 s ischemia initiated either immediately at the onset of reperfusion (IPo) or after reperfusion for 3 min (delayed-IPo). Combination of IPC and IPo was performed by combining both protocols.

MEASUREMENTS AND MAIN RESULTS

Intestinal ischemia/reperfusion resulted in significant intestinal injury evidenced as significant increase in Chiu's scores and wet-to-dry intestine weight ratio accompanied with increases in plasma levels of tumor necrosis factor-alpha and interleukin-6, as well as increases in the intestinal tissue lipid peroxidation product malonediadehyde and myeloperoxidase activity as compared to control animals (all P < 0.05). All these changes were significantly attenuated either by IPC or IPo or their combination (P < 0.05), and not by delayed-IPo (P > 0.05). IPC and IPo showed synergistic protection compared with either protocol alone.

CONCLUSION

Ischemic postconditioning reduces intestinal injury, in part, by inhibiting oxidative injury, neutrophils filtration and proinflammatory response. The early period of reperfusion is critical to intestinal protection by IPo, and intestinal protection with IPo can be enhanced by IPC.

Propofol pretreatment reduces ceramide production and attenuates intestinal mucosal apoptosis induced by intestinal ischemia/reperfusion in rats

BACKGROUND

Apoptosis has been shown to be a major mode of intestinal epithelial cell death caused by intestinal ischemia/reperfusion (II/R), a condition that is associated with increased oxidative stress. Ceramide has been proposed as a messenger of apoptosis. We investigated if pretreatment with propofol, an anesthetic with antioxidant properties, could reduce ceramide production, and consequently, mucosal epithelial apoptosis induced by II/R in rats.

METHODS

Rat II/R injury was produced by clamping the superior mesenteric artery for 1 h followed by 3 h of reperfusion. Thirty rats were randomly allocated into control, injury (II/R) and propofol (pretreatment) groups (n = 10 per group). In the propofol group, propofol 50 mg/kg, a dose that has been shown to cause the loss of reflex responses to a painful stimulus while remaining sensitive to skin incision in rats, was administered intraperitoneally 30 min before inducing intestinal ischemia, while animals in control and untreated injury groups received an equal volume of intralipid. Intestinal mucosal epithelial apoptosis was detected via electron microscopy and TUNEL analysis. Lipid oxidation product malondialdehyde and the activities of superoxide dismutase were assessed by colorimetric analyses. Ceramide generation and sphingomyelinase mRNA expression in intestinal mucosa were determined by high performance thin layer chromatography and reverse transcriptase polymerase chain reaction, respectively.

RESULTS

II/R caused intestinal mucosal epithelial apoptosis and over-production of ceramide accompanied by up-regulation of sphingomyelinase mRNA expression and increases in lipid oxidation (all P < 0.01 versus control). Propofol pretreatment significantly attenuated these changes (all P < 0.01, propofol versus injury).

CONCLUSION

The findings indicate that propofol pretreatment attenuates II/R-induced intestinal epithelial apoptosis, which might be attributable to its antioxidant property modulating the ceramide pathway.

Immediate but not delayed postconditioning during reperfusion attenuates acute lung injury induced by intestinal ischemia/reperfusion in rats: comparison with ischemic preconditioning

BACKGROUND

A previous study has shown that brief period of repetitive superior mesenteric artery (SMA) occlusion and reperfusion applied at the onset of reperfusion, ischemic postconditioning (IPo), attenuates intestinal injury after intestinal ischemia/reperfusion (II/R). This study tested the hypothesis that IPo would attenuate II/R-induced acute lung injury, which is comparable to ischemic preconditioning (IPC) and the brief period of postconditioning applied at the onset of reperfusion is critical to pulmonary protection by IPo.

METHODS

Rat II/R injury was produced by clamping SMA for 60 min followed by 60 min of reperfusion. The rats were randomly allocated into one of five groups based upon the intervention (n = 8): sham operation (Sham): sham surgical preparation including isolation of the SMA without occlusion was performed; Injury: there was no intervention either before or after SMA occlusion; ischemia preconditioning (IPC): the SMA was occluded for 10 min followed by 10 min of reperfusion before prolonged occlusion; ischemia postconditioning (IPo): three cycles of 30 sec reperfusion-30 sec reocclusion were imposed immediately upon reperfusion (3 min total intervention); delayed postconditioning: clamping was completely released for full reperfusion for 3 min (the duration of the IPo algorithm), after which three cycles of 30 sec occlusion and reperfusion were applied.

RESULTS

Histologic results showed severe damage in rat lungs in the injury group evidenced by increased lung wet/dry weight ratio and pulmonary permeability index, which was accompanied by increases in the levels of plasma TNFalpha and IL-6, the pulmonary malondialdehyde (MDA), and the pulmonary myeloperoxidase (MPO) activity and a decrease in superoxide dismutase (SOD) activity. IPo, not delayed IPo, could significantly attenuate lung injury and improve the above variables, which was comparable to IPC.

CONCLUSIONS

IPo at onset of reperfusion reduces acute lung injury induced by II/R, which may be mediated, in part, by inhibiting oxidant generation, neutrophils filtration, and proinflammatory mediators releases. The early period of reperfusion in the rat model is critical to pulmonary protection by IPo. IPo may improve outcome in clinical conditions associated with II/R.