Baicalein Preconditioning Cardioprotection Involves Pro-Oxidant Signaling and Activation of Pyruvate Dehydrogenase.

Preconditioning has a powerful protective potential against myocardial ischemia-reperfusion injury (I/R). Our prior work demonstrated that baicalein, a flavonoid derived from the root of Scatellaria baicalensis Georgi (also known as Huangqin), confers this preconditioning protection. This study further explored the mechanisms of baicalein preconditioning (BC-PC) in mouse cardiomyocytes. Cells were treated with baicalein (10 µM) for a brief period of time (10 min) prior to simulated ischemia 90 min/reperfusion for 180 min. Baicalein triggered an induction of a small amount of mitochondrial reactive oxygen species (ROS) prior to the initiation of ischemia, assessed by 6-carboxy-2', 7'-dichlorodihydrofluorescein diacetate (6-carboxy-H2DCFDA). It also significantly increased cell viability measured by propidium iodide (PI) and lactate dehydrogenase and preserved mitochondrial membrane potential assessed by TMRM fluorescence intensity. Myxothiazol, a mitochondrial electron transport chain complex III inhibitor, partially blocked ROS generation induced by BC-PC and reduced cell viability. BC-PC increased phosphorylation of Akt (Thr308 and Ser473) and eNOS Ser1177, and nitric oxide (NO) production measured using 4,5-diaminofluorescein diacetate (DAF-2 DA, 1 µM). Akt inhibitor API-2 abolished Akt phosphorylation and reduced DAF-2 production and cell viability. In addition, BC-PC decreased phosphorylation of pyruvate dehydrogenase (PDH) reflecting upregulated PDH activity, and increased ATP production at 30 min during reperfusion. Taken together, baicalein preconditioning-induced cardioprotection involves pro-oxidant generation, activates survival signaling Akt/eNOS/NO, and improves metabolic recovery after I/R injury. Our work provides new perspectives on the effect of baicalein on cardiac preconditioning against I/R injury.

2019 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations.

The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research.

Baicalein Cardioprotection via Oxidant Scavenging and Akt-Nitric Oxide Signaling: Identification of Early Reperfusion Phase as the Critical Therapeutic Window.

Baicalein is a natural flavonoid with anti-oxidant activities protecting against ischemia/reperfusion (I/R) injury. Previous studies suggest that oxidative burst early after reperfusion accelerates cell death. We therefore investigated the critical therapeutic window of baicalein by examining the timing of baicalein treatment in relation to its oxidant modulating and cytoprotective effects. Using an established chick cardiomyocyte model of I/R, we administered baicalein at various time points after reperfusion and assessed cell viability and the profiles of reactive oxygen species (ROS), nitric oxide (NO), and Akt phosphorylation. Baicalein administered at the onset of reperfusion resulted in a concentration-dependent reduction of cell death (25 µM 48.2±1.9%, 50µM 43.8±1.5%, 100µM 36.6±2.1%, vs. I/R control 57.3±1.4%, all p<0.05). Baicalein (100µM) timely and effectively scavenged ROS burst and enhanced NO production in the early reperfusion phase. Cotreatment with NO synthase (NOS) inhibitor l-NAME (200µM) partially abrogated the cytoprotective effect. Baicalein (100µM) given after reperfusion lost protective effect in a time-dependent manner with cytoprotection completely lost if >60min. Even with only 15-min delay after reperfusion, the ROS scavenging effect was abolished and the NO enhancing effect markedly reduced. The phosphorylation of Akt, an upstream regulator of eNOS, also diminished as the delay lengthened. In conclusion, baicalein treatment after reperfusion confers cardioprotection in a concentration- and time-dependent manner. The critical therapeutic window lies in the early reperfusion phase, during which ROS scavenging and Akt-eNOS mediated NO signaling are most effective.

Citrus peel extracts attenuated obesity and modulated gut microbiota in mice with high-fat diet-induced obesity.

Polymethoxyflavones (PMFs) and hydroxyl PMFs (HOPMFs) are mainly found in citrus peel and have shown anti-obesity potential in in vitro and in vivo studies. Herein, we have investigated the anti-obesity effects of two citrus peel extracts obtained via supercritical fluid extraction: PMF A, with a lower content of PMFs and HOPMFs, and PMF B, with a higher content of PMFs and HOPMFs. PMF A and PMF B were administered orally for 16 weeks to mice with high fat diet (HFD)-induced obesity. The results showed that PMF B decreased the lipid content more statistically significantly (p < 0.05) than PMF A in 3T3-L1 preadipocytes, reduced the adipocyte size, decreased the adipose tissue weight and alleviated the total body weight in the HFD mice. Both PMF A and PMF B reduced the adipocyte size in the perigonadal fat by markedly decreasing the levels of lipid droplets (LD) and perilipin 1 protein and Sterol regulatory element binding protein 1 (SREBP-1) expression. Compared to the case of the HFD group, PMF B altered the gut microbiota by increasing Prevotella and decreasing rc4-4 bacteria. The change in the composition of gut microbiota, the community of symbiotic and pathogenic microorganisms, may determine the metabolic health and be responsible for the anti-obesity mechanism. Our results indicate that the citrus peel extracts decrease lipid accumulation both in vivo and in vitro and should be considered for the management of overweight and obesity conditions.

Baicalein Preventive Treatment Confers Optimal Cardioprotection by PTEN/Akt/NO Activation.

Baicalein is a flavonoid with excellent oxidant scavenging capability. It has been reported to protect against a variety of oxidative injuries including ischemia/reperfusion (I/R). However, the optimal treatment strategy for I/R injury and the protective mechanisms are not fully understood. In this study we employed an established chick cardiomyocyte model of I/R and investigated the effects of three baicalein treatment strategies on reactive oxygen species (ROS) scavenging, nitric oxide (NO) production and cell viability. The molecular signaling pathways were also explored. Compared to the I/R control (cell death 52.2[Formula: see text][Formula: see text][Formula: see text]2.0%), baicalein preventive treatment (25[Formula: see text][Formula: see text]M, pretreated for 72[Formula: see text]h and continued through I/R) conferred the best protection (19.5[Formula: see text][Formula: see text][Formula: see text]3.9%, [Formula: see text]), followed by I/R treatment (treated during I/R) and reperfusion treatment (treated at reperfusion only). Preventive and I/R treatments almost completely abolished ROS generation during both ischemic and reperfusion phases, and increased NO production and Akt phosphorylation. Reperfusion treatment reduced the ROS burst in the early reperfusion phase only, and had no effect on NO production and Akt activation. Further, the phosphorylation of phosphatase and tensin homolog (PTEN), a phosphatase negatively regulating Akt activation, was significantly increased by baicalein preventive treatment and slightly by the I/R treatment. PTEN protein expression was reduced in the same trend accordingly. Baicalein reperfusion treatment had no effects on PTEN phosphorylation and expression. Our results indicate that baicalein preventive treatment confers optimal cardioprotection against I/R injury, and this protection involves effective oxidant scavenging and the activation of PTEN/Akt/NO pathway.

Toward functional screening of cardioactive and cardiotoxic drugs with zebrafish in vivo using pseudodynamic three-dimensional imaging.

Given the high mortality in patients with cardiovascular diseases and the life-threatening consequences of drugs with unforeseen adverse effects on hearts, a critical evaluation of the pharmacological response of cardiovascular function on model animals is important especially in the early stages of drug development. We report a proof-of-principle study to demonstrate the utility of zebrafish as an analytical platform to predict the cardiac response of new drugs or chemicals on human beings. With pseudodynamic 3D imaging, we derive individual parameters that are central to the cardiac function of zebrafish, including the ventricular stroke volume, ejection fraction, cardiac output, heart rate, diastolic filling function, and ventricular mass. We evaluate both inotropic and chronotropic responses of the heart of zebrafish treated with drugs that are commonly prescribed and possess varied known cardiac activities. We reveal deranged cardiac function of a zebrafish model of cardiomyopathy induced with a cardiotoxic drug. The cardiac function of zebrafish exhibits a pharmacological response similar to that of human beings. We compare also cardiac parameters obtained in this work with those derived with conventional 2D approximation and show that the latter tends to overestimate the cardiac parameters and produces results of greater variation. In view of the growing interest of using zebrafish in both fundamental and translational biomedical research, we envisage that our approach should benefit not only contemporary pharmaceutical development but also exploratory research such as gene, stem cell, or regenerative therapies targeting congenital or acquired heart diseases.

Baicalein preconditioning protects cardiomyocytes from ischemia-reperfusion injury via mitochondrial oxidant signaling.

Previous studies suggest baicalein, in addition to its antioxidant effects, protects against hypoxia/reoxygenation injury via its pro-oxidant properties. We hypothesize that a brief period of baicalein treatment prior to ischemia/reperfusion (I/R) may trigger preconditioning protection via a mitochondrial pro-oxidant mechanism. Using an established chick cardiomyocyte model of I/R, cells were preconditioned with baicalein (10 µM) for 10 min followed by 10-min wash prior to I/R. Intracellular oxidants were measured using 2', 7'-dichlorofluorescin diacetate (DCFH/DA). Cell viability was assessed by propidium iodide and apoptosis determined by DNA fragmentation. Baicalein induced a transient but significant increase of DCF fluorescence within the 10-min preconditioning period, and led to significant reduction of cell death (38.9 ± 1.8% vs. 58.7 ± 1.2% in I/R control, n = 6, p < 0.001) and DNA fragmentation after I/R. Cotreatment with N-acetylcysteine (500 µM), mitochondrial complex III electron transport chain inhibitor myxothiazol (1 µM), mitochondrial KATP channel blocker 5-hydroxydecanoate-Na (5-HD, 500 µM) or anion channel inhibitor 4', 4'-diisothiocyanato-stilbene-2, 2'-disulfonic acid (DIDS, 200 µM) resulted in significant abrogation of oxidant increase during induction as well as the protection conferred by baicalein preconditioning. These results suggest that baicalein preconditioning exhibits significant anti-apoptotic protection against cardiomyocyte I/R injury by mitochondrial oxidant signaling, which was in part mediated by mitochondrial KATP channel and anion channel opening.

Grape seed proanthocyanidins protect cardiomyocytes from ischemia and reperfusion injury via Akt-NOS signaling.

Ischemia/reperfusion (I/R) injury in cardiomyocytes is related to excess reactive oxygen species (ROS) generation and can be modulated by nitric oxide (NO). We have previously shown that grape seed proanthocyanidin extract (GSPE), a naturally occurring antioxidant, decreased ROS and may potentially stimulate NO production. In this study, we investigated whether GSPE administration at reperfusion was associated with cardioprotection and enhanced NO production in a cardiomyocyte I/R model. GSPE attenuated I/R-induced cell death [18.0 +/- 1.8% (GSPE, 50 microg/ml) vs. 42.3 +/- 3.0% (I/R control), P < 0.001], restored contractility (6/6 vs. 0/6, respectively), and increased NO release. The NO synthase (NOS) inhibitor Nomega-nitro-L-arginine methyl ester (L-NAME, 200 microM) significantly reduced GSPE-induced NO release and its associated cardioprotection [32.7 +/- 2.7% (GSPE + L-NAME) vs. 18.0 +/- 1.8% (GSPE alone), P < 0.01]. To determine whether GSPE induced NO production was mediated by the Akt-eNOS pathway, we utilized the Akt inhibitor API-2. API-2 (10 microM) abrogated GSPE-induced protection [44.3% +/- 2.2% (GSPE + API-2) vs. 27.0% +/- 4.3% (GSPE alone), P < 0.01], attenuated the enhanced phosphorylation of Akt at Ser473 in GSPE-treated cells and attenuated GSPE-induced NO increases. Simultaneously blocking NOS activation (L-NAME) and Akt (API-2) resulted in decreased NO levels similar to using each inhibitor independently. These data suggest that in the context of GSPE stimulation, Akt may help activate eNOS, leading to protective levels of NO. GSPE offers an alternative approach to therapeutic cardioprotection against I/R injury and may offer unique opportunities to improve cardiovascular health by enhancing NO production and increasing Akt-eNOS signaling.

Curry leaf (Murraya koenigii Spreng.) reduces blood cholesterol and glucose levels in ob/ob mice.

We observed that curry leaf (Murraya koenigii) extract possesses the property to decrease blood cholesterol and blood glucose levels in diabetic ob/ob mice. Mice received daily intraperitoneal injections of 80 mg/kg curry leaf extract for 10 consecutive days. The extract significantly decreased blood cholesterol level from 277.6 +/- 16.6 mg/d (day 0) to 182.0 +/- 15.3 mg/d (day 10, p < 0.01 compared with the change in vehicle group). The extract also significantly decreased blood glucose level from 387.0 +/- 15.6 mg/dl (day 0) to 214.0 +/- 26.6 mg/dl (day 10, p < 0.01). In addition, body weight was reduced after extract treatment. Our data suggest that curry leaf may be proved to be of clinical importance in improving the management of high cholesterol level and type 2 diabetes.

Scutellaria baicalensis decreases ritonavir-induced nausea.

BACKGROUND: Protease inhibitors, particularly ritonavir, causes significant gastrointestinal disturbances such as nausea, even at low doses. This ritonavir-induced nausea could be related to its oxidative stress in the gut. Alleviation of drug-induced nausea is important in effectively increasing patients' compliance and improving their quality of life. Conventional anti-emetic drugs can only partially abate the symptoms in these patients, and their cost has also been a concern. Rats respond to nausea-producing emetic stimuli by increasing consumption of non-nutritive substances like kaolin or clay, a phenomenon known as pica. In this study, we used this rat pica model to evaluate the effects of Scutellaria baicalensis, a commonly used oriental herbal medicine, on ritonavir-induced nausea. RESULTS: Rats treated with 20 mg/kg ritonavir significant caused increases of kaolin consumption at 24 to 48 hr (P < 0.01). Pretreatment with 0.3 and 3 mg/kg Scutellaria baicalensis extract significantly decreased ritonavir-induced kaolin intake in a dose-related manner (P < 0.01). Compared to vehicle treatment, the extract completely prevented ritonavir-induced kaolin consumption at dose 3 mg/kg. The area under the curves (AUC) for kaolin intake from time 0 to 120 hr for vehicle only, ritonavir only, SbE 0.3 mg/kg plus ritonavir, and SbE 3 mg/kg plus ritonavir were 27.3 g x hr, 146.7 g x hr, 123.2 g x hr, and 32.7 g x hr, respectively. The reduction in area under the curves of kaolin intake from time 0 to 120 hr between ritonavir only and SbE 0.3 mg/kg plus ritonavir, ritonavir only and SbE 3 mg/kg plus ritonavir were 16.0% and 77.7%, respectively. CONCLUSION: Scutellaria baicalensis significantly attenuated ritonavir-induced pica, and demonstrated a potential in treating ritonavir-induced nausea.

Effects of ganoderma lucidum extract on chemotherapy-induced nausea and vomiting in a rat model.

Chemotherapy is highly cytotoxic, causing a number of severe adverse effects such as nausea and vomiting. Herbal medicines, which can often be used on a daily basis for prolonged treatment, may be clinically beneficial. Ganoderma lucidum or Lingzhi mushroom has been recognized as a remedy in treating a number of medical conditions, including balancing immunity and decreasing drug-induced side effects. It has been shown that rats react to emetic stimuli, like the chemotherapy agent cisplatin, by increased consumption of kaolin, known as pica; and this rat model has been utilized to evaluate novel anti-emetic compounds. In this study, we evaluated the effects of a G. lucidum extract (SunRecome, the most commonly used Lingzhi mushroom extract in China) in attenuating cisplatin-induced nausea and vomiting in the rat pica model. We observed that intraperitoneal cisplatin injection caused a significant increase in kaolin intake at 24, 48, 72 and 96 hours, reflecting cisplatin's nausea and vomiting action. This cisplatin-induced kaolin intake dose-dependently decreased after 1, 3 and 10 mg/kg G. lucidum extract injection (p < 0.01). In addition, there was a significant reduction of food intake after cisplatin. The cisplatin-induced food intake reduction improved significantly after G. lucidum extract administrations in a dose-related manner (p < 0.01), suggesting a supportive effect of the extract on general body condition. Future controlled clinical trials are needed to evaluate the safety and effectiveness of this herbal medication.

Hawthorn: potential roles in cardiovascular disease.

Hawthorn (Crataegus) may play a role in the prevention and treatment of cardiovascular diseases such as hypertension, hyperlipidemia, and in particular, congestive heart failure. Evidence is accumulating that hawthorn may induce anti-ischemia/reperfusion-injury, anti-arrhythmic, hypolipidemic and hypotensive effects. These beneficial effects may in part be due to the presence of antioxidant flavonoid components. While a number of studies have been performed to evaluate the clinical efficacy of hawthorn, an international, multicenter, prospective clinical study including a large number of New York Heart Association (NYHA) class II/III heart failure patients is ongoing to test hawthorn's long-term therapeutic effects. Further clinical trials as well as pharmacokinetic and mechanistic studies are needed to explore and confirm its effectiveness, safety and pharmacological mechanism.

Polyphenol contents in grape-seed extracts correlate with antipica effects in cisplatin-treated rats.

BACKGROUND: Grape-seed (Vitis spp.) extract (GSE) is a widely used antioxidant dietary supplement. Chemotherapeutic agents such as cisplatin induce oxidative damage in the gastrointestinal tract and cause nausea and vomiting. MATERIALS AND METHODS: A rat model of simulated emesis was used to observe that cisplatin significantly increased kaolin consumption (or pica). Three GSEs from different sources were used in this study. RESULTS: High-performance liquid chromatographic analysis of five major constituents (gallic acid, catechin, epicatechi, procyanidin B2, and epicatechin gallate) revealed that each constituent had different levels in the three GSEs. Extract #1, prepared in the laboratory of the investigators, had the lowest total polyphenol content (27.27 mg/g); Extract #2, obtained from a dietary supplement company in the United States, had a somewhat higher level (35.84 mg/g); and Extract #3, obtained from China, had the highest level (194.21 mg/g). Subsequently these GSEs were intraperitoneally administered in rats to evaluate their ability to decreasing cisplatin induced pica. At 10 mg/kg all three GSEs, with varying degrees of effect, decreased cisplatin-induced pica. The areas under the curves of kaolin intake from time 0 to 72 hours, compared to those in the cisplantin-only group, were reduced 45% for Extract #1 (p < 0.01), 54% for Extract #2 (p < 0.01), and 66% Extract #3 (p < 0.001). CONCLUSIONS: The study data showed variable polyphenol contents and proportions in the three GSEs correlated to variable pharmacologic effects, indicating the importance of standardization of herbal product preparations. However further increasing of the GSE doses reversed the antipica effects of GSEs, probably because of their pro-oxidant effects. Results from this study suggest that an appropriate dose of GSE has therapeutic value in treating cisplatin-induced emesis.

Ascorbate supplement reduces oxidative stress in dyslipidemic patients undergoing apheresis.

OBJECTIVE: The effect of ascorbate treatment on apheresis-induced oxidative stress in uremic and dyslipidemic patients was evaluated. METHODS AND RESULTS: We developed a chemiluminescence-emission spectrum and high-performance liquid chromatography analysis to assess the effect of ascorbate supplement on plasma reactive oxygen species (ROS) scavenging activity and oxidized lipid/protein production in hyperlipidemic and uremic patients undergoing apheresis. Apheresis was efficient in reduction of atherogenic lipoproteins, complement, fibrinogen, soluble intercellular adhesion molecule-1, and oxidative parameters including phosphatidylcholine hydroperoxide (PCOOH), malonaldehyde, methylguanidine, and diotyrosine. Apheresis itself, however, activated leukocytes to increase ROS activity and reduced the plasma ROS scavenging activity. Ascorbate administration selectively diminished apheresis-enhanced H2O2 and inflammatory mediators such as tumor necrosis factor alpha (TNF-alpha) and monocyte chemoattractant protein-1. Chronically dyslipidemic and uremic patients undergoing biweekly apheresis plus ascorbate treatment had lower levels of C-reactive protein and PCOOH than did those without ascorbate treatment during a 6-month follow-up study period. CONCLUSIONS: We demonstrate that apheresis with ascorbate treatment provides a therapeutic potential in reducing atherosclerotic risk via inhibition of H2O2-induced oxidative stress in patients with uremia or dyslipidemia.