Hyperbaric oxygen improves cerebral ischemia-reperfusion injury in rats via inhibition of ferroptosis.

BACKGROUND: Our previous study found that hyperbaric oxygen (HBO) attenuated cognitive impairment in mice induced by cerebral ischemia-reperfusion injury (CIRI). However, its mechanism of action is not fully understood. In this study, we aimed to establish a rat model of cerebral ischemia-reperfusion, explore the possible role of ferroptosis in the pathogenesis of CIRI, and observe the effect of HBO on ferroptosis-mediated CIRI. METHODS: Sprague Dawley (SD) rats were randomly divided into control, model, Ferrostatin-1 (Fer-1), HBO and Fer-1+ HBO groups. Morris water maze, myelin basic protein (MBP) and ß-tubulin immunoreactivity were assessed to evaluate the neuroprotective effects of HBO on cerebral ischemia reperfusion injury. Ferroptosis were examined to investigate the mechanism underlying the effects of HBO. RESULTS: Our result showed that Fer-1 and HBO improved learning and memory ability in the navigation trail and probe trail of the Morris water maze and increased MBP and ß-tubulin immunoreactivity of the cortex in the model rats. The levels of ferritin, malondialdehyde (MDA) and glutathione (GSH) in the serum were also reversed by Fer-1 and HBO treatment. Mitochondrial cristae dissolution and vacuolization were observed in the model group by transmission electron microscopy and these conditions were improved in the Fer-1 and HBO groups. Furthermore, Fer-1 and HBO treatment reversed Prostaglandin-Endoperoxide Synthase 2 (PTGS2), Iron Responsive Element Binding Protein 2 (IREB2), acyl-CoA synthetase long chain family member 4 (ACSL4) and Solute Carrier Family 7 Member 11 (SLC7A11) mRNA levels and Transferrin Receptor 1 (TFR1), ferritin light chain (FTL), ferritin heavy chain 1 (FTH1), glutathione peroxidase 4 (GPX4), Nuclear factor E2-related factor 2 (Nrf2), lysophosphatidylcholine acyltransferase 3 (LPCAT3), c-Jun N-terminal kinase (JNK), phosphorylated c-Jun N-terminal kinase (P-JNK) phosphorylated Extracellular signal-regulated protein kinase (P-ERK) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) protein levels. The above changes were more pronounced in Fer-1+ HBOGroup. DISCUSSION: The results of the present study indicated that HBO improves cerebral ischemia-reperfusion injury in rats, which may be related to inhibition of ferroptosis. This also means that ferroptosis may become a new target of HBO against CIRI.

Research progress of sophoridine's pharmacological activities and its molecular mechanism: an updated review.

Background: Sophoridine, the major active constituent of Sophora alopecuroides and its roots, is a bioactive alkaloid with a wide range of pharmacological effects, including antitumor, anti-inflammatory, antiviral, antibacterial, analgesic, cardioprotective, and immunoprotective activities. Sophora flavescens Aiton is a traditional Chinese medicine that is bitter and cold. Additionally, it also exhibits the effects of clearing heat, eliminating dampness, and expelling insects. Aims of the study: To summarize the pharmacological research and associated mechanisms of sophoridine, we compiled this review by combining a huge body of relevant literature. Materials and methods: The information related to this article was systematically collected from the scientific literature databases including PubMed, Google Scholar, Web of Science, Science Direct, Springer, China National Knowledge Infrastructure, published books, PhD and MS dissertations. Results: Its antitumor activity is particularly remarkable, as it can inhibit cancer cell proliferation, invasion, and metastasis while inducing cell cycle arrest and apoptosis. Additionally, sophoridine also holds therapeutic potential for myocardial ischemia, osteoporosis, arrhythmias, and neurological disorders, primarily through the suppression of related inflammatory factors and cell apoptosis. However, sophoridine has also exhibited adverse effects such as hepatotoxicity and neurotoxicity. The antidisease effect and mechanism of sophoridine are diverse, so it has high research value. Conclusion: As an important traditional Chinese medicine alkaloid, modern pharmacological studies have demonstrated that sophoridine has prominent bioactivities, especially on anti-tumor anti-inflammation activities, and cardiovascular system protection. These activities provide prospects for novel drug development for cancer and some chronic diseases. Nevertheless, the understanding of the multitarget network pharmacology, long-term in vivo toxicity, and clinical efficacy of sophoridine require further detailed research.

Camrelizumab plus rivoceranib versus sorafenib as first-line therapy for unresectable hepatocellular carcinoma (CARES-310): a randomised, open-label, international phase 3 study.

BACKGROUND: Immunotherapy with immune checkpoint inhibitors combined with an anti-angiogenic tyrosine-kinase inhibitor (TKI) has been shown to improve overall survival versus anti-angiogenic therapy alone in advanced solid tumours, but not in hepatocellular carcinoma. Therefore, a clinical study was conducted to compare the efficacy and safety of the anti-PD-1 antibody camrelizumab plus the VEGFR2-targeted TKI rivoceranib (also known as apatinib) versus sorafenib as first-line treatment for unresectable hepatocellular carcinoma. METHODS: This randomised, open-label, international phase 3 trial (CARES-310) was done at 95 study sites across 13 countries and regions worldwide. Patients with unresectable or metastatic hepatocellular carcinoma who had not previously received any systemic treatment were randomly assigned (1:1) to receive either camrelizumab 200 mg intravenously every 2 weeks plus rivoceranib 250 mg orally once daily or sorafenib 400 mg orally twice daily. Randomisation was done via a centralised interactive response system. The primary endpoints were progression-free survival, as assessed by the blinded independent review committee per Response Evaluation Criteria in Solid Tumours version 1.1, and overall survival in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of the study drugs. We report the findings from the prespecified primary analysis for progression-free survival and interim analysis for overall survival. This study is registered with ClinicalTrials.gov (NCT03764293). FINDINGS: Between June 28, 2019, and March 24, 2021, 543 patients were randomly assigned to the camrelizumab-rivoceranib (n=272) or sorafenib (n=271) group. At the primary analysis for progression-free survival (May 10, 2021), median follow-up was 7·8 months (IQR 4·1-10·6). Median progression-free survival was significantly improved with camrelizumab-rivoceranib versus sorafenib (5·6 months [95% CI 5·5-6·3] vs 3·7 months [2·8-3·7]; hazard ratio [HR] 0·52 [95% CI 0·41-0·65]; one-sided p<0·0001). At the interim analysis for overall survival (Feb 8, 2022), median follow-up was 14·5 months (IQR 9·1-18·7). Median overall survival was significantly extended with camrelizumab-rivoceranib versus sorafenib (22·1 months [95% CI 19·1-27·2] vs 15·2 months [13·0-18·5]; HR 0·62 [95% CI 0·49-0·80]; one-sided p<0·0001). The most common grade 3 or 4 treatment-related adverse events were hypertension (102 [38%] of 272 patients in the camrelizumab-rivoceranib group vs 40 [15%] of 269 patients in the sorafenib group), palmar-plantar erythrodysaesthesia syndrome (33 [12%] vs 41 [15%]), increased aspartate aminotransferase (45 [17%] vs 14 [5%]), and increased alanine aminotransferase (35 [13%] vs eight [3%]). Treatment-related serious adverse events were reported in 66 (24%) patients in the camrelizumab-rivoceranib group and 16 (6%) in the sorafenib group. Treatment-related death occurred in two patients: one patient in the camrelizumab-rivoceranib group (ie, multiple organ dysfunction syndrome) and one patient in the sorafenib group (ie, respiratory failure and circulatory collapse). INTERPRETATION: Camrelizumab plus rivoceranib showed a statistically significant and clinically meaningful benefit in progression-free survival and overall survival compared with sorafenib for patients with unresectable hepatocellular carcinoma, presenting as a new and effective first-line treatment option for this population. FUNDING: Jiangsu Hengrui Pharmaceuticals and Elevar Therapeutics.

An active fraction from Spatholobus suberectus dunn inhibits the inflammatory response by regulating microglia activation, switching microglia polarization from M1 to M2 and suppressing the TLR4/MyD88/NF-κB pathway in LPS-stimulated BV2 cells.

Neurodegenerative disorders are known to be associated with neuroinflammation caused by microglia. Therefore, regulation of microglia activation and polarization to inhibit neuroinflammatory reactions seems to hold promise as a therapeutic approach in neurodegenerative disorders. Spatholobus suberectus Dunn (SSD) has been utilized as a traditional Chinese medicine remedy for brain diseases for thousands of years. SSD possesses various pharmacological activities, such as circulation invigoration, neuroprotection, and anti-inflammatory. The objective of this research was to examine the anti-neuroinflammatory effects and molecular mechanisms of an active fraction from SSD (ASSD) in vitro culture BV2 cells, a type of mouse microglia cell line. The inflammatory responses in BV2 cells were induced by stimulating them with 1 µg/mL lipopolysaccharide (LPS) and the effects of ASSD on LPS-stimulated inflammation were monitored. Besides, by using the methods of Western blot, immunofluorescence, and RT-PCR, the mechanisms of ASSD on microglia activation, M1/M2 polarization, and the TLR4/MyD88/NF-κB pathway were investigated. Our findings demonstrate that the treatment doses of ASSD neither induce cytotoxicity nor promote the production of inflammatory cytokines. In addition, immunofluorescence analysis show that ASSD inhibited the expression of ionized calcium-binding adapter molecule 1(Iba1) and inducible nitricoxide synthase (iNOS), and induced arginase 1 (Arg1) expression. Moreover, Western blot analysis indicated that ASSD significantly down-regulated TLR4, MyD88, p-IκB, NF-κB p65, and NF-κB p-p65 protein expression levels. Furthermore, RT-qPCR assay show that ASSD significantly down-regulated iNOS, TLR4, MyD88, and NF-κB mRNA expression levels, and up-regulated Arg1 mRNA expression level. According to the findings, ASSD can suppress microglia-mediated inflammatory responses by modulating microglia activation, inducing a shift from M1 to M2 polarization, and inhibiting the TLR4/MyD88/NF-κB signaling pathway.

Integrative analysis of bulk and single-cell gene expression profiles to identify tumor-associated macrophage-derived CCL18 as a therapeutic target of esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a common gastrointestinal malignancy with poor patient prognosis. Current treatment for ESCC, including immunotherapy, is only beneficial for a small subset of patients. Better characterization of the tumor microenvironment (TME) and the development of novel therapeutic targets are urgently needed. METHODS: In the present study, we hypothesized that integration of single-cell transcriptomic sequencing and large microarray sequencing of ESCC biopsies would reveal the key cell subtypes and therapeutic targets that determine the prognostic and tumorigenesis of ESCC. We characterized the gene expression profiles, gene sets enrichment, and the TME landscape of a microarray cohort including 84 ESCC tumors and their paired peritumor samples. We integrated single-cell transcriptomic sequencing and bulk microarray sequencing of ESCC to reveal key cell subtypes and druggable targets that determine the prognostic and tumorigenesis of ESCC. We then designed and screened a blocking peptide targeting Chemokine C-C motif ligand 18 (CCL18) derived from tumor associated macrophages and validated its potency by MTT assay. The antitumor activity of CCL18 blocking peptide was validated in vivo by using 4-nitroquinoline-1-oxide (4-NQO) induced spontaneous ESCC mouse model. RESULTS: Comparative gene expression and cell-cell interaction analyses revealed dysregulated chemokine and cytokine pathways during ESCC carcinogenesis. TME deconvolution and cell interaction analyses allow us to identify the chemokine CCL18 secreted by tumor associated macrophages could promote tumor cell proliferation via JAK2/STAT3 signaling pathway and lead to poor prognosis of ESCC. The peptide Pep3 could inhibit the proliferation of EC-109 cells promoted by CCL18 and significantly restrain the tumor progression in 4-NQO-induced spontaneous ESCC mouse model. CONCLUSIONS: For the first time, we discovered and validated that CCL18 blockade could significantly prevent ESCC progression. Our study revealed the comprehensive cell-cell interaction network in the TME of ESCC and provided novel therapeutic targets and strategies to ESCC treatment.

Hyperbaric oxygen protects HT22 cells and PC12 cells from damage caused by oxygen-glucose deprivation/reperfusion via the inhibition of Nrf2/System Xc-/GPX4 axis-mediated ferroptosis.

This study was to investigate the protective effect of hyperbaric oxygen (HBO) on HT22 and PC12 cell damage caused by oxygen-glucose deprivation/reperfusion-induced ferroptosis. A 2-h oxygen-glucose deprivation and 24-h reperfusion model on HT22 and PC12 cells was used to simulate cerebral ischemia-reperfusion injury. Cell viabilities were detected by Cell Counting Kit-8 (CCK-8) method. The levels of reactive oxygen species (ROS) and lipid reactive oxygen species (Lipid ROS) were detected by fluorescent probes Dihydroethidium (DHE) and C11 BODIPY 581/591. Iron Colorimetric Assay Kit, malondialdehyde (MDA) and glutathione (GSH) activity assay kits were used to detect intracellular iron ion, MDA and GSHcontent. Cell ferroptosis-related ultrastructures were visualized using transmission electron microscopy (TEM). Furthermore, PCR and Western blot analyses were used to detect the expressions of ferroptosis-related genes and proteins. After receiving oxygen-glucose deprivation/reperfusion, the viabilities of HT22 and PC12 cells were significantly decreased; ROS, Lipid ROS, iron ions and MDA accumulation occurred in the cells; GSH contents decreased; TEM showed that cells were ruptured and blebbed, mitochondria atrophied and became smaller, mitochondrial ridges were reduced or even disappeared, and apoptotic bodies appeared. And the expressions of Nrf2, SLC7A11 and GPX4 genes were reduced; the expressions of p-Nrf2/Nrf2, xCT and GPX4 proteins were reduced. Notably, these parameters were significantly reversed by HBO, indicating that HBO can protect HT22 cells and PC12 cells from damage caused by oxygen-glucosedeprivation/reperfusion via the inhibition of Nrf2/System Xc-/GPX4 axis-mediated ferroptosis.

[Diterpenoids from Rabdosia flexicaulis].

The genus Rabdosia is famous for the abundance of diverse and novel ent-kaurane diterpenoids. However, only a few ent-kauranoids have been discovered from R. flexicaulis since the investigation on its chemical constituents is not systematic. To find novel bioactive diterpenoids, the ethyl acetate extract of the above ground part of R. flexicaulis in Daofu County, Sichuan Province was obtained by column chromatography. One new compound and five known ones were identified as flexicaulin E(1), forrestin B(2), inf-lexarabdonin D(3), 7α-hydroxydehydroabietic acid(4), 15-hydroxydehydroabietic acid(5), and pomiferin F(6) by spectral techniques. Compounds 1-3 were the ent-kaurane diterpenoids isolated from this species for the first time. Compounds 4-6, aromatic abie-tanoids, were isolated from the genus Rabdosia for the first time.

Rapid Detection of Anti-SARS-CoV-2 Antibody Using a Selenium Nanoparticle-Based Lateral Flow Immunoassay.

Coronavirus disease 2019 is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 is highly transmissible. Early and rapid testing is necessary to effectively prevent and control the outbreak. Detection of SARS-CoV-2 antibodies with lateral flow immunoassay can achieve this goal. In this study, SARS-CoV-2 nucleoprotein (NP) was expressed and purified. We used the selenium nanoparticle as the labeling probe coupled with the NP to prepare an antibody (IgM and IgG) detection kit. The detection limit, cross reaction, sensitivity and specificity of the kit is verified. Separate detection of IgM and IgG, such as in this assay, was performed in order to reduce mutual interference and improve the accuracy of the test results.The final purity of NP was 91.83%. Selenium nanoparticle and NP successfully combined with stable effect. The LOD of the kit was 20 ng/mL for anti-NP IgG and 60 ng/mL for anti-NP IgM, respectively. The kit does not cross reaction with RF. The sensitivity of the kit was 94.74% and the specificity was 96.23%. The assay kit does not require any special device for reading the results and the readout is a simple color change that can be evaluated with the naked eye. This kit is suitable for rapid and real-time detection of the SARS-CoV-2 antibody IgG and IgM.

Does Serum Vitamin D Level Affect COVID-19 Infection and Its Severity?-A Case-Control Study.

BACKGROUND: As effective medication to treat COVID-19 is currently unavailable, preventive remedies may be particularly important. OBJECTIVE: To examine the relationship between serum 25-hydroxy vitamin D (25(OH)D) level and COVID-19 infection, its severity, and its clinical case characteristics. METHODS: This case-control study compared serum 25(OH)D levels and rates of vitamin D deficiency (VDD) between 80 healthy controls and 62 patients diagnosed with COVID-19 and admitted to Guangxi People's Hospital, China, 2/16/2020-3/16/2020. Cases were categorized into asymptomatic, mild/moderate, and severe/critical disease. Logistic regression analysis was conducted to examine the associations between 25(OH)D level, or VDD, and case status/severity of COVID-19 while controlling for demographics and comorbidities. A threshold level of vitamin D for conveying COVID-19 risk was estimated. RESULTS: Severe/critical COVID-19 cases were significantly older and had higher percentages of comorbidity (renal failure) compared to mild cases. The serum 25(OH)D concentration in COVID-19 patient was much lower than that in healthy control. And 25(OH)D level was the lowest in severe/critical cases, compared with mild cases. In further, significantly higher rates of VDD were found in COVID-19 cases (41.9%) compared to healthy controls (11.1%). And VDD was the greatest in severe/critical cases (80%), compared with mild cases (36%). These statistically significant associations remained even after controlling for demographics and comorbidities. A potential threshold of 25(OH)D (41.19 nmol/L) to protect against COVID-19 was identified. CONCLUSION: Elderly and people with comorbidities were susceptible to severe COVID-19 infection. VDD was a risk factor for COVID-19, especially for severe/critical cases. While further confirmation is needed, vitamin D supplementation may have prevention or treatment potential for COVID-19 disease.

Hyperbaric oxygen protects against myocardial ischemia­reperfusion injury through inhibiting mitochondria dysfunction and autophagy.

Our previous study demonstrated that hyperbaric oxygen (HBO) improves heart function predominantly through reducing oxygen stress, modulating energy metabolism and inhibiting cell apoptosis. The present study aimed to investigate the protective effects of HBO on mitochondrial function and autophagy using rats with a ligated left anterior descending artery. The cardioprotective effects of HBO were mainly evaluated using ELISA, fluorescent probes, transmission electron microscopy and reverse transcription­quantitative PCR (RT­qPCR). HBO pretreatment for 14 days (once a day) using a 0.25 MPa chamber improved mitochondrial morphology and decreased the number of autophagic vesicles, as observed using a transmission electron microscope. HBO pretreatment significantly increased the levels of ATP, ADP, energy charge and the opening of the mitochondrial permeability transition pore, but decreased the levels of AMP, cytochrome c and reactive oxygen species. Moreover, HBO pretreatment significantly increased the gene or protein expression levels of eIF4E­binding protein 1, mammalian target of rapamycin (mTOR), mitochondrial DNA, NADH dehydrogenase subunit 1, mitofusin 1 and mitofusin 2, whereas it decreased the gene or protein expression levels of autophagy­related 5 (Atg5), cytochrome c, dynamin­related protein 1 and p53, as determined using RT­qPCR or immunohistochemistry. In conclusion, HBO treatment was observed to protect cardiomyocytes during myocardial ischemia­reperfusion injury (MIRI) by preventing mitochondrial dysfunction and inhibiting autophagy. Thus, these results provide novel evidence to support the use of HBO as a potential agent for the mitigation of MIRI.

Effect of an aqueous extract of Averrhoa carambola L. on endothelial function in rats with ventricular remodelling.

Ventricular remodelling leads to cardiomyocyte hypertrophy, myocardial fibrosis, endothelial vasoactive substance changes and endothelial dysfunction. Our purpose was to research the effect of an aqueous extract of Averrhoa carambola L. (AEA) on endothelial function in rats with ventricular remodelling induced by isoprenaline. Rats were subjected to injection of isoprenaline and administration of various drugs. Vasoactive substances were measured, and the ventricular remodelling index was detected by the weighing method. Immunohistochemical analysis, pathological examination, Western blot and Masson's trichrome staining were performed. After AEA administration, the levels of transforming growth factor-ß (TGF-ß), angiotensin II (AngII), inducible NO synthase (iNOS), endothelin-converting enzyme (ECE), and endothelin 1 (ET-1); the ventricular remodelling index; and the collagen volume fraction were decreased, while the levels of total NO synthase (tNOS) and endothelial NO synthase (eNOS) were increased. The pathological examination results showed that apoptosis, fibrosis, necrosis and inflammatory infiltration of myocardial tissue were attenuated by AEA treatment. AEA might alleviate ventricular remodelling in rats by maintaining the balance of vasoactive substances and the function of the vascular endothelium.

Effect and mechanism of vitamin D on the development of colorectal cancer based on intestinal flora disorder.

BACKGROUND: To investigate the correlation between the level of circulating vitamin D and the development of colorectal cancer (CRC) and to clarify the effect and mechanism of vitamin D on the development of CRC. METHODS: Serum samples from 63 patients with CRC (CRC group) and 61 healthy volunteers (normal group) were collected. Azoxymethane + dextran sodium sulfate-induced CRC mouse model and dietary models with different doses of vitamin D were established to verify whether vitamin D supplementation could reverse the occurrence and development of CRC at the overall animal level. Intestinal barrier integrity and microbial defense response were evaluated by detection of intestinal flora and expression of related genes. RESULTS: In the clinical serum samples, compared with the normal group, the level of 25 (OH) D3 in the CRC group was relatively low (P < 0.01), which was consistent with the clinical situation in mice. Vitamin D deficiency aggravated the deterioration of enteritis and intestinal cancer in CRC mice, whereas the overall condition of CRC mice improved after vitamin D supplementation. Vitamin D has a significant regulatory effect on the homeostasis of the intestinal flora, particularly in the regulation of intestinal probiotics, Akkermansia muciniphila-mediated colon barrier integrity. CONCLUSIONS: Vitamin D deficiency is closely related to the high incidence of CRC, and vitamin D supplementation can inhibit the occurrence and development of CRC. Vitamin D plays a role in the reversal of CRC mainly through the regulation of intestinal flora, especially the regulation of A. muciniphila-mediated colon barrier integrity.

Hyperbaric oxygen alleviated cognitive impairments in mice induced by repeated cerebral ischemia-reperfusion injury via inhibition of autophagy.

AIMS: In this study, we investigate the effect and underlying mechanism of hyperbaric oxygen (HBO) treatment on a model of repeated cerebral ischemia-reperfusion injury (IR). MAIN METHODS: Eighty rats were randomly separated into sham, vehicle, hyperbaric air (HBA; 0.25 MPa, 60 min), and HBO (0.25 MPa, 60 min) groups. Repeated cerebral IR was induced by ligating the right and left bilateral common carotid arteries for 10 min and then allowing reperfusion for 10 min. This pattern was repeated three times. The neuroprotective effects of HBO were assessed by animal behavior, neuron morphology, inflammatory markers, intracellular calcium ion content, and autophagy-related protein and gene expression. KEY FINDINGS: Our result showed that HBO improved learning and memory in the navigation trail and probe trail of the Morris water maze, and these findings were supported by the observation data from 2,3,5-Triphenyltet-razolium chloride staining, Nissl staining, and electron microscopic. Importantly, we found that HBO reduced excessive autophagy in the prefrontal cortex, which was evidenced by activating of the mammalian target of the rapamycin (mTOR) and 4E-BP1, as well as suppression of LC3II and ATG5. Moreover, HBO significantly inhibited the cerebral IR-induced inflammatory reaction. Furthermore, HBO treatment modulated autophagy pathway-related factors, including producing a decrease in the intracellular calcium ion concentration and p53 level; meanwhile, the levels of BDNF and p-Akt were increased. SIGNIFICANCE: Our results indicated that HBO protected against IR-induced neuron injury by attenuating autophagy, inflammation, and calcium overload. These results provide a new mechanism and laboratory evidence for clinical treatment of VD.

The Multiple Applications and Possible Mechanisms of the Hyperbaric Oxygenation Therapy.

Hyperbaric Oxygenation Therapy (HBOT) is used as an adjunctive method for multiple diseases. The method meets the routine treating and is non-invasive, as well as provides 100% pure oxygen (O2), which is at above-normal atmospheric pressure in a specialized chamber. It is well known that in the condition of O2 deficiency, it will induce a series of adverse events. In order to prevent the injury induced by anoxia, the capability of offering pressurized O2 by HBOT seems involuntary and significant. In recent years, HBOT displays particular therapeutic efficacy in some degree, and it is thought to be beneficial to the conditions of angiogenesis, tissue ischemia and hypoxia, nerve system disease, diabetic complications, malignancies, Carbon monoxide (CO) poisoning and chronic radiation-induced injury. Single and combination HBOT are both applied in previous studies, and the manuscript is to review the current applications and possible mechanisms of HBOT. The applicability and validity of HBOT for clinical treatment remain controversial, even though it is regarded as an adjunct to conventional medical treatment with many other clinical benefits. There also exists a negative side effect of accepting pressurized O2, such as oxidative stress injury, DNA damage, cellular metabolic, activating of coagulation, endothelial dysfunction, acute neurotoxicity and pulmonary toxicity. Then it is imperative to comprehensively consider the advantages and disadvantages of HBOT in order to obtain a satisfying therapeutic outcome.

Effect of Yulangsan Polysaccharide on the Reinstatement of Morphine-Induced Conditioned Place Preference in Sprague-Dawley Rats.

We previously reported that Yulangsan polysaccharide (YLSP), which was isolated from the root of Millettia pulchra Kurz, attenuates withdrawal symptoms of morphine dependence by regulating the nitric oxide pathway and modulating monoaminergic neurotransmitters. In this study, we investigated the effects and mechanism of YLSP on the reinstatement of morphine-induced conditioned place preference (CPP) in rats. A CPP procedure was employed to assess the behavior of rats, and indicators of serum and four brain regions (nucleus accumbens, ventral tegmental area, hippocampus and prefrontal cortex) were determined to explore its underlying mechanism. YLSP inhibited priming morphine-induced reinstatement of CPP in a dose-dependent manner. YLSP markedly reduced nitric oxide and nitric oxide synthase levels in the brain. Moreover, YLSP significantly decreased the dopamine and norepinephrine levels in the serum and brain. Furthermore, YLSP significantly decreased cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) concentrations, inhibited the expression of dopamine D1 receptors and cAMP response element binding protein mRNA, and improved the expression of dopamine D2 receptor mRNA in the four brain regions. Our findings indicated that YLSP could inhibit the reinstatement of morphine-induced CPP possibly by modulating the NO-cGMP and D1R-cAMP signaling pathways.

Hyperbaric Oxygen Attenuates Withdrawal Symptoms by Regulating Monoaminergic Neurotransmitters and NO Signaling Pathway at Nucleus Accumbens in Morphine-Dependent Rats.

In this study, we examined whether hyperbaric oxygen (HBO2) plays a detoxification role in withdrawal symptoms in a morphine-dependent rat model. The model was established through injections of morphine at increasing doses for 7 days. Withdrawal symptoms were induced by naloxone injection on the 8th day. The detoxification effect of HBO2 was evaluated using the withdrawal symptom scores, biochemical indices and neurotransmitters. Compared with the model group, HBO2 therapy significantly attenuated the withdrawal symptom scores, body weight loss and the level of norepinephrine level, whereas it increased the dopamine level and tyrosine hydroxylase expression in the nucleus accumbens. Moreover, HBO2 therapy substantially alleviated the NO, NOS, cAMP, and cGMP levels. Our findings indicate that HBO2 can effectively alleviate withdrawal symptoms induced by morphine dependence, and these effects may be attributed to the modulation of monoaminergic neurotransmitters and the suppression of the NO-cGMP signaling pathway.

Hyperbaric Oxygen Prevents Cognitive Impairments in Mice Induced by D-Galactose by Improving Cholinergic and Anti-apoptotic Functions.

Our previous study demonstrated that hyperbaric oxygen (HBO) improved cognitive impairments mainly by regulating oxidative stress, inflammatory responses and aging-related gene expression. However, a method for preventing cognitive dysfunction has yet to be developed. In the present study, we explored the protective effects of HBO on the cholinergic system and apoptosis in D-galactose (D-gal)-treated mice. A model of aging was established via systemic intraperitoneal injection of D-gal daily for 8 weeks. HBO was administered during the last 2 weeks of D-gal injection. Our results showed that HBO in D-gal-treated mice significantly improved behavioral performance on the open field test and passive avoidance task. Studies on the potential mechanisms of this effect showed that HBO significantly reduced oxidative stress and blocked the nuclear factor-κB pathway. Moreover, HBO significantly increased the levels of choline acetyltransferase and acetylcholine and decreased the activity of acetylcholinesterase in the hippocampus. Furthermore, HBO markedly increased expression of the anti-apoptosis protein Bcl-2 and glial fibrillary acidic protein meanwhile decreased expression of the pro-apoptosis proteins Bax and caspase-3. Importantly, there was a significant reduction in expression of Aß-related genes, such as amyloid precursor protein, ß-site amyloid cleaving enzyme-1 and cathepsin B mRNA. These decreases were accompanied by significant increases in expression of neprilysin and insulin-degrading enzyme mRNA. Moreover, compared with the Vitamin E group, HBO combined with Vitamin E exhibited significant difference in part of the above mention parameters. These findings suggest that HBO may act as a neuroprotective agent in preventing cognitive impairments.

Protective Effect of Hyperbaric Oxygen on Cognitive Impairment Induced by D-Galactose in Mice.

Memory decline is characteristic of aging and age-related neurodegenerative disorders. This study was designed to investigate the protective effect of hyperbaric oxygen (HBO) against cognitive impairment induced by D-galactose (D-gal) in mice. D-gal was intraperitoneally injected into mice daily for 8 weeks to establish the aging model. HBO was simultaneously administered once daily. The results indicate that HBO significantly reversed D-gal-induced learning and memory impairments. Studies on the potential mechanisms of this action showed that HBO significantly reduced oxidative stress by increasing superoxide dismutase, glutathione peroxidase, and catalase levels, as well as the total anti-oxidation capability, while decreasing the content of malondialdehyde, nitric oxide, and nitric oxide synthase in the hippocampal CA1 region. HBO also inhibited advanced glycation end-product formation and decreased levels of tumor necrosis factor-α and interleukin-6. Moreover, HBO significantly attenuated D-gal-induced pathological injury in the hippocampus, as well as ß-amyloid protein1-42 expression and retained BDNF expression. Furthermore, HBO decreased p16, p21 and p53 gene and protein expression in the hippocampus of D-gal-treated mice. In conclusion, the protective effect of HBO against D-gal-induced cognitive impairment was mainly due to its ability to reduce oxidative damage, suppress inflammatory responses, and regulate aging-related gene expression.

Cardioprotective Effects of Combined Therapy with Hyperbaric Oxygen and Diltiazem Pretreatment on Myocardial Ischemia-Reperfusion Injury in Rats.

BACKGROUND/AIMS: In this study, we examined whether the combination of hyperbaric oxygen (HBO) and diltiazem therapy provided a cardioprotective effect on myocardial ischemia-reperfusion injury (MIRI) rat model. METHODS: Sixty healthy Sprague-Dawley rats were randomly divided into sham, IR, diltiazem (5 mg/kg), HBO (0.25 MPa, 60 min) and combination therapy (HBO plus diltiazem) groups. MIRI model was established by ligating the left anterior descending for 30 min, followed by 60 min of reperfusion. RESULTS: The results show that HBO and diltiazem preconditioning significantly improves cardiac function and myocardial infarction area, increases nitric oxide, endothelial nitric oxide synthase and ATPase (Na+-K+-ATPase and Ca2+-Mg2+-ATPase) activity and decreases levels of oxygen stress, myocardial enzymes and endothelin-1. Notably, HBO and diltiazem preconditioning significantly increased Bcl-2 protein expression and decreased Bax protein and caspase-3 mRNA expression. CONCLUSIONS: These data indicate that combination therapy protected against heart MIRI by reducing oxygen stress damage, correcting energy metabolism, improving endothelial function and inhibiting cell apoptosis.

Toxicological evaluation of Yulangsan polysaccharide in Wistar rats: A 26-week oral gavage study.

Although numerous studies have proven the medicinal values of Yulangsan polysaccharide (YLSP), the toxicity of this active ingredient is unknown. In the acute toxicity study, a single oral administration of 24 g/kg YLSP caused neither toxicological symptoms nor mortality, and the LD50 was estimated >24 g/kg. In the chronic toxicity study, we administered doses of 0, 0.6, 1.2 and 2.4 g/kg YLSP in rats by oral gavage for 26 weeks followed by a 3-week recovery period. There was no mortality or remarkable clinical signs observed during this 26-week study. Additionally, there were no toxic differences in the following parameters: body weight, food consumption, hematology, clinical biochemistry, organ weight, and macroscopic findings. There were no adverse effects on histopathology observed in males or female rats treated with YLSP. Based on the results, the no-observed-adverse-effect-level of YLSP in rats is greater than 2.4 g/kg when administered orally for 26 consecutive weeks.