Bombesin protects myocardium against ischemia/reperfusion injury via activation of the Keap1-Nrf2-HO-1 signaling pathway.

AIMS: It has been reported that some peptides released by the gastro-intestinal tract play important roles in the prevention of myocardial ischemia/reperfusion injury (MIRI). Bombesin (BN) is a biologically active peptide released by non-adrenergic non-cholinergic nerves on the gastric antrum mucosa controlled by the vagus nerve. However, there is a lack of reports on the impact of BN on MIRI. This study aimed to explore the influence of BN on MIRI and its underlying mechanism. MATERIALS AND METHODS: MIRI was induced by either 30min of global ischemia in Langendorff perfused rat hearts, or by ligation of the descending coronary artery for 30min in anesthetized Spraque-Dawley rats, and both were followed by 120min reperfusion. Infarct size and left ventricular function were assessed, and lactate dehydrogenase (LDH), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) levels were measured spectrophotometrically, while cardiomyocyte apoptosis was detected by TUNEL assay. The content of BN in plasma was measured with enzyme-linked immunosorbent assays (ELISA). The expression of caspase 3, Kelch-like ECH-associated protein 1 (Keap1), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) were quantified. KEY FINDINGS: BN and vagus nerve stimulation improved cardiac contractile function and reduced myocardial infarct size, attenuated oxidative stress damage and myocardial cell apoptosis, increased the expression of Keap1, Nrf2, and HO-1. and these effects were blocked by using a BN receptor antagonist. SIGNIFICANCE: BN provides protection against MIRI, and its underlying mechanism is through activation of the Keap1/Nrf2/HO-1 pathway. This research provides more reliable evidence for the "gut-heart axis dialogue" and explores potential therapeutic approaches for MIRI.

Relationship between ferroptosis and mitophagy in cardiac ischemia reperfusion injury: a mini-review.

Cardiovascular diseases (CVD), with high morbidity and mortality, seriously affect people's life and social development. Clinically, reperfusion therapy is typically used to treat ischemic cardiomyopathy, such as severe coronary heart disease and acute myocardial infarction. However, reperfusion therapy can lead to myocardial ischemia reperfusion injury (MIRI), which can affect the prognosis of patients. Studying the mechanisms of MIRI can help us improve the treatment of MIRI. The pathological process of MIRI involves many mechanisms such as ferroptosis and mitophagy. Ferroptosis can exacerbate MIRI, and regulation of mitophagy can alleviate MIRI. Both ferroptosis and mitophagy are closely related to ROS, but there is no clear understanding of the relationship between ferroptosis and mitophagy. In this review, we analyzed the relationship between ferroptosis and mitophagy according to the role of mTOR, NLPR3 and HIF. In addition, simultaneous regulation of mitophagy and ferroptosis may be superior to single therapy for MIRI. We summarized potential drugs that can regulate mitophagy and/or ferroptosis, hoping to provide reference for the development of drugs and methods for MIRI treatment.

Mechanism and Protective Effect of Smilax glabra Roxb on the Treatment of Heart Failure via Network Pharmacology Analysis and Vitro Verification.

Smilax glabra Roxb (SGR) has been widely applied alone or in combination with other Chinese herbs in heart failure (HF), but its mechanism and protective effect have not been investigated. We aimed to explore the mechanism and protective effect of SGR on the treatment of HF. Network pharmacology analysis predicted that SGR was involved in the regulation of cell proliferation, oxidation-reduction process, apoptotic process, ERK1 and ERK2 cascade, MAPK cascade, etc. Its mechanism was mainly involved in the MAPK signaling pathway, calcium signaling pathway, cardiac muscle contraction, etc. Subsequently, SGR was proved to improve cellular viability, restore cellular morphology, suppress cellular and mitochondrial ROS production, improve H2O2-induced lysosome inhibition, attenuate mitochondrial dysfunction, and protect mitochondrial respiratory and energy metabolism in H9c2 cells. SGR activated the p38MAPK pathway by decreasing the mRNA expression of AKT, PP2A, NF-KB, PP2A, RAC1, and CDC42 and increasing the mRNA expression of Jun, IKK, and Sirt1. SGR also decreased the protein expression of ERK1, ERK2, JNK, Bax, and Caspase3 and increased the protein expression of p38MAPK and Bcl-2. In addition, Istidina at the highest degree was identified in SGR via the UHPLCLTQ-Orbitrap-MSn method, and it was suggested as anti-heart failure agents by targeting SRC with molecular docking analysis. In conclusion, SGR has a protective effect on HF through cellular and mitochondrial protection via multi-compounds and multi-targets, and its mechanism is involved in activating the p38 MAPK pathway. Istidina may be possible anti-HF agents by targeting SRC.

Study on extraction methods of polysaccharides from a processed product of Aconitum carmichaeli Debx.

Traditional Chinese medicine PaoTianXiong (PTX) is a processed product of Aconitum carmichaeli Debx. with polysaccharide as the main ingredient. The properties of PTX polysaccharide (PTXP) may be affected by different extraction methods. To develop and utilize PTXP better, it is of great significance to study the extraction methods of PTXP. Thus, we extracted PTXPs with dilute alkaline water extraction, ultrasound-assisted extraction, cellulase-assisted extraction, and hot water extraction (HWE), respectively. The characterizations of PTXPs extracted by different methods were analyzed based on purity determination, infrared analysis, molecular weight and monosaccharide composition. And antioxidant experiments of PTXPs were conducted. The results showed that PTXPs extracted by the four extraction methods were all glucan. After purification, the PTXPs showed similar antioxidant activity in vitro. The molecular weight of polysaccharides extracted by the cellulase-assisted method was different from that extracted by the other three methods. Our results showed that not only the yield but also the effect of extraction methods on the properties of PTXP should be considered when selecting the best extraction method. Therefore, HWE was considered to be the best extraction method of PTXP. The yield and purity of purified PTXP were 24.5% and 97.1%, respectively. The optimized extraction conditions were: an extraction temperature of 90 °C, extraction time of 2.17 h, solid-liquid ratio of 1 : 29 (g mL-1), and number of extractions of 2.

Comparative antitumor and anti-inflammatory effects of flavonoids, saponins, polysaccharides, essential oil, coumarin and alkaloids from Cirsium japonicum DC.

Cirsium japonicum DC (Asteraceae) is a perennial thistle widely distributed in Asia, it is also consumed as functional food and herb in China. To analyze the health effects of C. japonicum, flavonoids, saponins, polysaccharides, essential oil, coumarin and alkaloids were extracted from C. japonicum, and their cytotoxicity to normal cells, anti-inflammatory effect against LPS-induced RAW 264.7 macrophages, antiproliferative effects against human lung adenocarcinoma cell A549 and anti-atherosclerosis activities in ox-LDL-stimulated RAW 264.7 cell were investigated. Results showed that coumarins exhibited strongest cell toxicity (IC50 = 162.7 µg/ml), and alkaloids showed slightly cytotoxicity at high concentration. Saponin could significantly inhibit cancer cell proliferation, especially for A549 cell and the inhibition rate reached to 47.0% at concentration of 200 µg/ml, which might result from the promotion of ROS generation in cancer cell. Saponin, essential oil and flavonoids could dose-dependently inhibit NO production in LPS-induced RAW 264.7 macrophages, whose inhibition rates were 65.4%, 73.0% and 80.4% at concentration of 50 µg/ml, respectively. Besides, saponin, essential oil and flavonoids also decreased lipid accumulation in ox-LDL-induced RAW 264.7 cell, which might be beneficial for cardiovascular health. These results indicated that different components from C. japonicum exhibited different bioactivities, providing useful information to better use thistle resources.

LC-MS/MS determination and comparative pharmacokinetics of strychnine, brucine and their metabolites in rat plasma after intragastric administration of each monomer and the total alkaloids from Semen Strychni.

A rapid, specific and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the simultaneous determination of strychnine, brucine, strychnine N-oxide and brucine N-oxide in rat plasma. Plasma samples were pretreated via simple protein precipitation with methanol and ephedrine hydrochloride was used as internal standard. Chromatographic separation was carried out on an ZORBAX Eclipse XDB-C18 column (2.1×150mm, 3.5µm) by gradient elution with methanol and 10mM ammonium acetate (adjusted to pH 4.0 with formic acid). The quantification of the analytes was performed by mass spectrometry with TurboIonSpray ionization (ESI) inlet in the positive ion multiple reaction monitoring (MRM) mode. The results showed that the calibration curve was linear in the concentration range of 0.510∼306.3ngmL(-1) for strychnine, brucine and 0.102∼306.0ngmL(-1) for strychnine N-oxide and brucine N-oxide, respectively. The intra- and inter-day precisions were less than 14.9%, and the accuracy ranged from 89.4 to 113% at three QC levels for the 4 analytes. The validated method was successfully applied to the pharmacokinetic study of strychnine, brucine, strychnine N-oxide and brucine N-oxide in rat plasma after oral administration of each monomer and the total alkaloids from Semen Strychni. After single oral administration of the total alkaloids from Semen Strychni at 4 dose levels, Cmax, AUC0-t of strychnine and brucine increased and were proportional to the oral doses. In comparative pharmacokinetics studies, no significant difference was found between each monomer and the total strychnos alkaloids on the pharmacokinetic parameters such as Cmax and AUC. Mean Cmax and AUC of strychnine and brucine were slight increased in the monomer groups in comparison to the total strychnos alkaloids groups, which suggested that some other alkaloids in the Semen Strychni may decrease the absorption of strychnine and brucine in body.