Cardioprotective Effect of Aloe vera Biomacromolecules Conjugated with Selenium Trace Element on Myocardial Ischemia-Reperfusion Injury in Rats

Recent Advances on Selenium Nutrition and Keshan Disease

Keshan disease (KD) is a type of endemic cardiomyopathy with an unknown cause. It is primarily found in areas in China with low selenium levels, from northeast to southwest. The nutritional biogeochemical etiology hypothesis suggests that selenium deficiency is a major factor in KD development. Selenium is important in removing free radicals and protecting cells and tissues from peroxide-induced damage. Thus, low environmental selenium may affect the selenium level within the human body, and selenium level differences are commonly observed between healthy people in KD and nonKD areas. From the 1970s to the 1990s, China successfully reduced KD incidence in endemic KD areas through a selenium supplementation program. After years of implementing prevention and control measures, the selenium level of the population in the KD areas has gradually increased, and the prevalence of KD in China has remained low and stable in recent years. Currently, the pathogenesis of KD remains vague, and the effect of selenium supplementation on the prognosis of KD still needs further study. This paper comprehensively reviews selenium deficiency and its connection to KD. Thus, this study aims to offer novel ideas and directions to effectively prevent and treat KD in light of the current situation.

Dexmedetomidine postconditioning attenuates myocardial ischemia/reperfusion injury by activating the Nrf2/Sirt3/SOD2 signaling pathway in the rats

OBJECTIVES

To observe the protective effects of dexmedetomidine (Dex) postconditioning on myocardial ischemia/reperfusion injury (IRI) and to explore its potential molecular mechanisms.

METHODS

One-hundred forty-seven male Sprague-Dawley rats were randomly divided into five groups receiving the different treatments: Sham, ischemia/reperfusion (I/R), Dex, Brusatol, Dex + Brusatol. By the in vivo rat model of myocardial IRI, cardioprotective effects of Dex postconditioning were evaluated by assessing serum CK-MB and cTnI levels, myocardial HE and Tunel staining and infarct size. Furthermore, the oxidative stress-related markers including intracellular ROS level, myocardial tissue MDA level, SOD and GSH-PX activities were determined.

RESULTS

Dex postconditioning significantly alleviated myocardial IRI, decreased intracellular ROS and myocardial tissue MDA level, increased SOD and GSH-PX activities. Dex postconditioning significantly up-regulated myocardial expression of Bcl-2, down-regulated Bax and cleaved caspase-3 and decreased cardiomyocyte apoptosis rate. furthermores, Dex postconditioning promoted Nrf2 nuclear translocation, increased myocardial expression of Sirt3 and SOD2 and decreased Ac-SOD2. However, brusatol reversed cardioprotective benefits of Dex postconditioning, significantly decreased Dex-induced Nrf2 nuclear translocation and reduced myocardial expression of Sirt3 and SOD2.

CONCLUSIONS

Dex postconditioning can alleviate myocardial IRI by suppressing oxidative stress and apoptosis, and these beneficial effects are at least partly mediated by activating the Nrf2/Sirt3/SOD2 signaling pathway.

Protective effect of Xinmai'an tablets via mediation of the AMPK/SIRT1/PGC-1α signaling pathway on myocardial ischemia-reperfusion injury in rats

BACKGROUND

Xinmai'an tablets are a compound Chinese medicine comprising six traditional Chinese medicines that have been clinically applied to treat cardiovascular diseases such as premature ventricular contractions for many years. However, pharmacological effects and underlying mechanisms of Xinmai'an tablet in protecting against myocardial ischemia-reperfusion injury (MIRI) were barely ever studied.

PURPOSE

To investigate the cardioprotective properties of Xinmai'an tablet against MIRI and the underlying molecular mechanism in rats.

METHODS

We initially established the UHPLC-QTRAP-MS/MS analysis method to ensure the controllable quality of Xinmai'an tablet. We further identified the cardioprotective effects of Xinmai'an tablet against MIRI using TTC staining, hematoxylin and eosin, echocardiography, the transmission electron microscope analysis, biochemical analysis, and ELISA. We then investigated whether the safeguarding effect of Xinmai'an tablet on MIRI model rats was related to AMPK/SIRT1/PGC-1α pathway via western blotting.

RESULTS

Xinmai'an tablet decreased myocardial infarct size; ameliorated cardiac function; alleviated myocardial and mitochondrial damage; and suppressed oxidative stress injury, vascular endothelial damage, and apoptosis response in MIRI model rats. Mechanistically, our results showed that Xinmai'an tablet can dramatically activate the AMPK/SIRT1/PGC-1αpathway and subsequently diminish mitochondrial oxidative stress damage. This was evidenced by increased ATP, Na+-K+-ATPase, and Ca2+-Mg2+-ATPase levels, upregulation of GLUT4, p-AMPK, SIRT1, and PGC-1α protein levels; and reduced GLUT1 protein level.

CONCLUSION

To the knowledge of the author of this article, this study is the first report of Xinmai'an tablet attenuating MIRI, potentially associated with the activation of the AMPK/SIRT1/PGC-1α pathway and subsequent reduction of mitochondrial oxidative stress damage. These findings reveal a novel pharmacological effect and mechanism of action of Xinmai'an tablet and highlight a promising therapeutic drug for ischemic cardiovascular diseases.

The Role of Selenium in Atherosclerosis Development, Progression, Prevention and Treatment

Selenium is an essential trace element that is essential for various metabolic processes, protection from oxidative stress and proper functioning of the cardiovascular system. Se deficiency has long been associated with multiple cardiovascular diseases, including endemic Keshan's disease, common heart failure, coronary heart disease, myocardial infarction and atherosclerosis. Through selenoenzymes and selenoproteins, Se is involved in numerous crucial processes, such as redox homeostasis regulation, oxidative stress, calcium flux and thyroid hormone metabolism; an unbalanced Se supply may disrupt these processes. In this review, we focus on the importance of Se in cardiovascular health and provide updated information on the role of Se in specific processes involved in the development and pathogenesis of atherosclerosis (oxidative stress, inflammation, endothelial dysfunction, vascular calcification and vascular cell apoptosis). We also discuss recent randomised trials investigating Se supplementation as a potential therapeutic and preventive agent for atherosclerosis treatment.

The effect of a standardized capsule of Aloe vera gel on the quality of life in patients with systolic heart failure: A randomized double-blind placebo-controlled clinical trial

This trial was designed to evaluate the effect of a standardized capsule of Aloe vera gel (AVG) on the quality of life (QOL) in patients with systolic heart failure (HF). Forty-two patients were randomly divided into two groups to receive either AVG 150 mg or harmonized placebo capsules twice a day for 8 weeks. The patients were evaluated before and after the intervention using the Minnesota Living with Heart Failure Questionnaire (MLHFQ), New York Heart Association (NYHA) functional class, six-minute walk test (6MWT), Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI) and STOP-BANG questionnaires. Post-intervention, AVG group indicated a significant reduction in the total score of MLHFQ (p < 0.001). The changes in MLHFQ and NYHA class were statistically significant after taking medication (p < 0.001 and p = 0.004, respectively). The change of 6MWT in the AVG group was more advanced; however, it was not statistically significant (p = 0.353). Moreover, in the AVG group, the severity of insomnia and obstructive sleep apnea decreased (p < 0.001, p = 0.01 respectively) and the sleep quality improved as well (p < 0.001). There were significantly fewer adverse events reported in the AVG group (p = 0.047). Therefore, AVG combined with standard medical therapy could provide more clinical benefits for patients with systolic HF.

Selenomethionine Alleviates Intestinal Ischemia-Reperfusion Injury in Mice Through the Bax-Caspase Pathway

Selenomethionine (SeMet) is known to alleviate ischemia-reperfusion (I/R) injury. However, its details of action have not been thoroughly elucidated in mice with intestinal I/R injury. In this study, intestinal I/R injury mice models were established, and ELISAs were performed to determine the levels of redox factors, including glutathione peroxidase (GSH-Px), catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA), in mice intestinal tissues. Furthermore, several apoptosis-related markers, such as cytochrome c (Cyt-c), Bcl-2, and Bax, were detected using qPCR and Western blotting, while caspase-3 was detected using Western blotting alone. The results showed that SeMet alleviated I/R damage by increasing GSH-Px, CAT, and SOD levels and reducing MDA levels. Our data demonstrated that SeMet reduced I/R injury and inhibited the expression of Cyt-c, Bax, and caspase-3. SeMet also increased the expression of Bcl-2 in the intestinal tissues of mice. In addition, the TUNEL assay results showed that SeMet mitigated apoptosis in the villi cells of the intestinal mucosa. The findings also revealed that I/R could lead to increased apoptosis levels and that SeMet alleviated I/R-induced apoptosis by mediating the Bax/cytochrome C/caspase-3 apoptotic signaling pathways in the intestinal I/R injury mice models. Thus, SeMet inhibited apoptosis and resulted in an increase of Bcl-2 levels; downregulated the expression of Bax, Cyt-c, and caspase-3; and alleviated the intestinal ischemia injury in mice. The I/R injury increased the cytosolic Bax, Cyt-c, and caspase-3 levels and significantly decreased Bcl-2 expression levels in the I/R group, compared to the Sham group. However, the levels of all markers were reversed post-SeMet pre-treatment.

Cardiovascular Protective Effects of Plant Polysaccharides: A Review

Cardiovascular disease is a kind of heart, brain, and blood vessel injury disease by the interaction of various pathological factors. The pathogenesis of cardiovascular disease is complex with various risk factors, including abnormally elevated blood pressure, glucose, and lipid metabolism disorders, atherosclerosis, thrombosis, etc. Plant polysaccharides are a special class of natural products derived from plant resources, which have the characteristics of wide sources, diverse biological activities, and low toxicity or side effects. Many studies have shown that plant polysaccharides improve cardiovascular diseases through various mechanisms such as anti-oxidative stress, restoring the metabolism of biological macromolecules, regulating the apoptosis cascade to reduce cell apoptosis, and inhibiting inflammatory signal pathways to alleviate inflammation. This article reviews the pharmacological effects and protective mechanisms of some plant polysaccharides in modulating the cardiovascular system, which is beneficial for developing more effective drugs with low side effects for management of cardiovascular diseases.

The Impact of Selenium Deficiency on Cardiovascular Function

Selenium (Se) is an essential trace element that is necessary for various metabolic processes, including protection against oxidative stress, and proper cardiovascular function. The role of Se in cardiovascular health is generally agreed upon to be essential yet not much has been defined in terms of specific functions. Se deficiency was first associated with Keshan’s Disease, an endemic disease characterized by cardiomyopathy and heart failure. Since then, Se deficiency has been associated with multiple cardiovascular diseases, including myocardial infarction, heart failure, coronary heart disease, and atherosclerosis. Se, through its incorporation into selenoproteins, is vital to maintain optimal cardiovascular health, as selenoproteins are involved in numerous crucial processes, including oxidative stress, redox regulation, thyroid hormone metabolism, and calcium flux, and inadequate Se may disrupt these processes. The present review aims to highlight the importance of Se in cardiovascular health, provide updated information on specific selenoproteins that are prominent for proper cardiovascular function, including how these proteins interact with microRNAs, and discuss the possibility of Se as a potential complemental therapy for prevention or treatment of cardiovascular disease.

Anti-hypertensive and cardioprotective activities of traditional Chinese medicine-derived polysaccharides: A review

Cardiovascular diseases (CVDs), a leading cause of death in modern society, have become a major public health issue globally. Although numerous approaches have been proposed to reduce morbidity and mortality, the pursuit of pharmaceuticals with more preventive and/or therapeutic value remains a focus of attention. Being a vast treasure trove of natural drug molecules, Traditional Chinese Medicine (TCM) has a long history of clinical use in the prophylaxis and remedy of CVDs. Increasing lines of preclinical evidence have demonstrated the effectiveness of TCM-derived polysaccharides on hindering the progression of CVDs, e.g. hypertension, myocardial infarction. However, to the best of our knowledge, there are few reviews on the application of TCM-derived polysaccharides in combating CVDs. Hence, we provide an overview of primary literature on the anti-hypertensive and cardioprotective activities of herbal polysaccharides. Additionally, we also discuss the current limitations and propose a new hypothesis about how polysaccharides exert cardiovascular effects based on the metabolism of polysaccharides.

Potential protective effects of Aloe vera gel on cardiovascular diseases: A mini-review

Cardiovascular diseases (CVDs) comprise the most prevalent causes of morbidity and mortality in both men and women worldwide. CVDs are associated with several risk factors such as hyperlipidemia, diabetes mellitus, hypertension, obesity, tobacco smoking and an unhealthy diet. Currently, in addition to the use of related pharmacological treatments in the management of CVDs, the investigation of other suitable healthcare approaches for these disorders such as the identification of herbal medicines has been considered in the scientific communities. Aloe vera (L.) Burm.f. is a perennial medicinal plant. The innermost leaf layer of this plant contains transparent gel, which is used as food. Pre-clinical studies have shown several biological activities of A. vera gel (AVG), including antidiabetic, lipid-lowering, antioxidant, antiinflammatory, hepatoprotective, and immunomodulatory effects. Other pharmacological activities of AVG such as anti-fibrotic, anti-hypertensive, and anti-atherosclerotic effects have been reported. Moreover, several clinical studies have demonstrated the ameliorating effects of AVG on some markers of CVDs risk factors. Thus, this study was conducted to review clinical trials besides in vitro and in vivo studies on the cardiac beneficial effects of AVG. However, further high-quality studies are needed to firmly establish the clinical efficacy of the plant.

Toxicology and pharmacology of synthetic organoselenium compounds: an update

Here, we addressed the pharmacology and toxicology of synthetic organoselenium compounds and some naturally occurring organoselenium amino acids. The use of selenium as a tool in organic synthesis and as a pharmacological agent goes back to the middle of the nineteenth and the beginning of the twentieth centuries. The rediscovery of ebselen and its investigation in clinical trials have motivated the search for new organoselenium molecules with pharmacological properties. Although ebselen and diselenides have some overlapping pharmacological properties, their molecular targets are not identical. However, they have similar anti-inflammatory and antioxidant activities, possibly, via activation of transcription factors, regulating the expression of antioxidant genes. In short, our knowledge about the pharmacological properties of simple organoselenium compounds is still elusive. However, contrary to our early expectations that they could imitate selenoproteins, organoselenium compounds seem to have non-specific modulatory activation of antioxidant pathways and specific inhibitory effects in some thiol-containing proteins. The thiol-oxidizing properties of organoselenium compounds are considered the molecular basis of their chronic toxicity; however, the acute use of organoselenium compounds as inhibitors of specific thiol-containing enzymes can be of therapeutic significance. In summary, the outcomes of the clinical trials of ebselen as a mimetic of lithium or as an inhibitor of SARS-CoV-2 proteases will be important to the field of organoselenium synthesis. The development of computational techniques that could predict rational modifications in the structure of organoselenium compounds to increase their specificity is required to construct a library of thiol-modifying agents with selectivity toward specific target proteins.

Comparative pharmacokinetics of seven bioactive components in normal, sham-operated, and myocardial ischemia-reperfusion injury rats after oral administration of the Salvia Miltiorrhiza-Moutan Cortex herb pair

Recently the Salvia Miltiorrhiza-Moutan Cortex (SM-MC) herb pair is considered as a promising Chinese medicinal mixture exhibiting a range of pharmacological activities, including treating cardiovascular disease due to its unique composition. In this study, we conducted the comparative pharmacokinetic analysis of seven main bioactive components of SM-MC in a different model rat. A straightforward ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) strategy that could simultaneously evaluate the levels of seven compounds was used to ensure the reliability of these pharmacokinetic analyses in rat plasma. The rat plasma samples were collected from normal, sham-operated, and myocardial ischemia-reperfusion injury (MIRI) groups at predetermined time points after the administration of SM-MC. The main pharmacokinetic parameters were detected and calculated. We successfully assessed the maximum concentration (C_max ), time to C_max (T_max ), the elimination rate constant (λ_z ), total half-life (t_1/2 ), total body clearance (CL), and the area under the concentration-time curve from 0 to last sampling time (AUC_0-t ) and extrapolated to infinity (AUC_0-∞ ). To sum up, an optimized UPLC-MS/MS approach that could be used to rapidly, simultaneously, and sensitively detect seven bioactive compounds derived from SM-MC extract preparations was successfully developed, which may offer a pharmacokinetic basis for preclinical and clinical studies of SM-MC herb pair for treating MIRI.

Foliar application of zinc and selenium alleviates cadmium and lead toxicity of water spinach - Bioavailability/cytotoxicity study with human cell lines

The present study investigated the effects of foliar application of zinc (Zn) and selenium (Se) on bioavailability of Zn and Se and toxicity of cadmium (Cd) and lead (Pb) to different water spinach ecotypes (LA and HA) grown in slightly (XZ) or moderately (LJY) contaminated fields via in vitro digestion combined with Caco-2/HL-7702 cell model. The obtained results revealed that foliar application of Zn and Se promoted yield, increased total, bioaccessible and bioavailable fractions of Zn and Se in plants, indicating that foliar application is a feasible way of biofortification. Although there was no significant effect on liver cell proliferation (MTT), membrane stability (LDH) and hepatocyte enzyme (ALT and AST) activities, the obvious ecotype and soil dependent fluctuations of lipid peroxidation (MDA) and antioxidant enzyme (SOD, POD and CAT) activities in serum highly suggest that the low accumulator and clean field should be used in agricultural production rather than the high accumulator and contaminated farmland. Moreover, foliar application of Zn and Se improved nutritional quality of all water spinach genotypes in both fields, including increased Fe, vitamin C, cellulose and chlorophyll, maintained concentrations of potassium (K), manganese (Mn), copper (Cu), protein, and nitrate. These results demonstrate that this agricultural management practice may prove to be an effective approach for minimizing health risk and alleviating "hidden hunger" in the developing countries.

Research progress on the biological activities of selenium polysaccharides

Selenium polysaccharides, an important organic selenium product, possess better antioxidant, antitumour, immune regulation, hypoglycaemic, and heavy metal removal activities than that of either polysaccharides or inorganic selenium.