Mechanism of salidroside relieving the acute hypoxia-induced myocardial injury through the PI3K/Akt pathway

Butylparaben induced zebrafish (Danio rerio) kidney injury by down-regulating the PI3K-AKT pathway

Butylparaben, a common endocrine disruptor in the environment, is known to be toxic to the reproductive system, heart, and intestines, but its nephrotoxicity has rarely been reported. In order to study the nephrotoxicity and mechanism of butylparaben, we examined the acute and chronic effects on human embryonic kidney cells (HEK293T) and zebrafish. Additionally, we assessed the potential remedial effects of salidroside against butylparaben-induced nephrotoxicity. Our in vitro findings demonstrated oxidative stress and cytotoxicity to HEK293T cells caused by butylparaben. In the zebrafish model, the concentration of butylparaben exposure ranged from 0.5 to 15 μM. An assortment of experimental techniques was employed, including the assessment of kidney tissue morphology using Hematoxylin-Eosin staining, kidney function analysis via fluorescent dextran injection, and gene expression studies related to kidney injury, development, and function. Additionally, butylparaben caused lipid peroxidation in the kidney, thereby damaging glomeruli and renal tubules, which resulted from the downregulation of the PI3K-AKT signaling pathway. Furthermore, salidroside ameliorated butylparaben-induced nephrotoxicity through the PI3K-AKT signaling pathway. This study reveals the seldom-reported kidney toxicity of butylparaben and the protective effect of salidroside against toxicological reactions related to nephrotoxicity. It offers valuable insights into the risks to kidney health posed by environmental toxins.

Knowledge, attitude, and practice of atrial fibrillation in high altitude areas

Background

To investigate the knowledge, attitude, and practice (KAP) of atrial fibrillation (AF) among the general population in high-altitude areas.

Methodology

A web-based cross-sectional study was conducted among the general population in high-altitude areas.

Results

A total of 786 valid questionnaires were enrolled, with a mean age of 34.75 ± 14.16 years. The mean score of knowledge, attitude and practice were 8.22 ± 6.50 (possible range: 0-10), 28.90 ± 5.63 (possible range: 8-40), 34.34 ± 6.44 (possible range: 9-45), respectively. The multivariate analysis showed that knowledge scores (OR = 1.108, 95% CI = 1.075-1.142, p < 0.001), attitude scores (OR = 1.118, 95% CI = 1.081-1.156, p < 0.001), and never smoking (OR = 2.438, 95% CI = 1.426-4.167, p = 0.001) were independently associated with proactive practice. The structural equation modeling (SEM) showed direct effect of knowledge on practice (p = 0.014), and attitude on practice (p = 0.004), while no effect of knowledge on attitude (p = 0.190).

Conclusion

The general population in high-altitude regions had adequate knowledge, positive attitude, and proactive practice towards AF. The SEM was suitable for explaining general population' KAP regarding AF, revealing that knowledge directly and positively affected attitude and practice.

Salidroside attenuates myocardial remodeling in DOCA-salt-induced mice by inhibiting the endothelin 1 and PI3K/AKT/NFκB signaling pathways

Myocardial remodeling, which occurs in the final stage of cardiovascular diseases such as hypertension, can ultimately result in heart failure. However, the pathogenesis of myocardial remodeling remains incompletely understood, and there is currently a lack of safe and effective treatment options. Salidroside, which is extracted from the plant Rhodiola rosea, shows remarkable antioxidant and anti-inflammatory characteristics. The purpose of this investigation was to examine the cardioprotective effect of salidroside on myocardial remodeling, and clarify the associated mechanism. Salidroside effectively attenuated cardiac dysfunction, myocardial hypertrophy, myocardial fibrosis, and cardiac inflammation, as well as renal injury and renal fibrosis in an animal model of deoxycortone acetate (DOCA)-salt-induced myocardial remodeling. The cardioprotective effect of salidroside was mediated by inhibiting the endothelin 1 and PI3K/AKT/NFκB signaling pathways. Salidroside was shown to inhibit the expression of endothelin1 in the hearts of mice treated with DOCA-salt. Additionally, it could prevent cardiomyocyte hypertrophy induced by endothelin-1 stimulation. Furthermore, Salidroside could effectively inhibit the excessive activation of the PI3K/AKT/NFκB pathway, which was caused by DOCA-salt treatment in mouse hearts and endothelin 1 stimulation in cardiomyocytes. Our study suggests that salidroside can be used as a therapeutic agent for the treatment of myocardial remodeling.

Fabrication of blended nanofibrous cardiac patch transplanted with TGF-β3 and human umbilical cord MSCs-derived exosomes for potential cardiac regeneration after acute myocardial infarction

Acute myocardial infarction (AMI) is a common cardiovascular condition that progressively results in heart failure. In the present study, we have designed to load transforming growth factor beta 3 (TGF-β3) and cardio potential exosomes into the blended polycaprolactone/type I collagen (PCL/COL-1) nanofibrous patch (Exo@TGF-β3@NFs) and examined its feasibility for cardiac repair. The bioactivity of the developed NFs towards the migration and proliferation of human umbilical vein endothelial cells was determined using in vitro cell compatibility assays. Additionally, Exo@TGF-β3/NFs showed up-regulation of genes involved in angiogenesis and mesenchymal differentiations in vitro. The in vivo experiments performed 4 weeks after transplantation showed that the Exo@TGF-β3@NFs had a higher LV ejection fraction and fraction shortening functions. Subsequently, it has been determined that Exo@TGF-β3@NFs significantly reduced AMI size and fibrosis and increased scar thickness. The developed NFs approach will become a useful therapeutic approach for the treatment of AMI.

Sweroside functionalized with Mesenchymal Stem cells derived exosomes attenuates sepsis-induced myocardial injury by modulating oxidative stress and apoptosis in rats

Sepsis is a life-threatening problem by organ dysfunction influenced by negative inflammatory responses and stimulated oxidative stress, which most of sepsis patients about 40-60% are accompanied with myocardial injury. Recently, stem cells derived exosomes could effectively apply in the numerous diseases by combined with natural therapeutic agents. In the present investigation, Sweroside functionalized with exosomes to control inflammatory responses by sepsis and significantly proved the function of depreciated myocardial injury-induced by LPS. The sweroside could have effectively delivered to cardiomyocytes cells via exosome carriers. The induced-SMI rats exhibited severe myocardial injury and apoptosis by in vivo experiments and treatment of sweroside-functionalized exosomes (SWO/EX) reassured the phenotypes. Importantly, SWO/EX significantly downregulated the ROS generation in the SMI rat models. The SOD and GSH activity were also suppressed in SMI rat models, and treated models with SWO/EXO could have effective liberating activity in the Rats. Meanwhile, SWO/EXO treated LPS-induced cardiomyocytes displayed that significant reduction of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) levels and also increasing cell survival and prevented apoptosis. Thus, we demonstrate that MS-cells derived exosome with sweroside could have effectively impede sepsis-induced myocardial injury. SWO/EX formulations might be applied as a potent therapeutic agent for SMI therapy.

A comprehensive review of natural products with anti-hypoxic activity

Natural products exhibit substantial impacts in the field of anti-hypoxic traetment. Hypoxia can cause altitude sickness and other negative effect on the body. Headache, coma, exhaustion, vomiting and, in severe cases, death are some of the clinical signs. Currently, hypoxia is no longer just a concern in plateau regions; it is also one of the issues that can not be ignored by urban residents. This review covered polysaccharides, alkaloids, saponins, flavonoids, peptides and traditional Chinese compound prescriptions as natural products to protect against hypoxia. The active ingredients, effectiveness and mechanisms were discussed. The related anti-hypoxic mechanisms involve increasing the hemoglobin (HB) content, glycogen content and adenosine triphosphate (ATP) content, removing excessive reactive oxygen species (ROS), reducing lipid peroxidation, regulating the levels of related enzymes in cells, protecting the structural and functional integrity of the mitochondria and regulating the expression of apoptosis-related genes. These comprehensive summaries are beneficial to anti-hypoxic research and provide useful information for the development of anti-hypoxic products.

Occlusion preconditioned mice are resilient to hypobaric hypoxia-induced myocarditis and arrhythmias due to enhanced immunomodulation, metabolic homeostasis, and antioxidants defense

Background

Sea-level residents experience altitude sickness when they hike or visit altitudes above ~2,500 m due to the hypobaric hypoxia (HH) conditions at such places. HH has been shown to drive cardiac inflammation in both ventricles by inducing maladaptive metabolic reprogramming of macrophages, which evokes aggravated proinflammatory responses, promoting myocarditis, fibrotic remodeling, arrhythmias, heart failure, and sudden deaths. The use of salidroside or altitude preconditioning (AP) before visiting high altitudes has been extensively shown to exert cardioprotective effects. Even so, both therapeutic interventions have geographical limitations and/or are inaccessible/unavailable to the majority of the population as drawbacks. Meanwhile, occlusion preconditioning (OP) has been extensively demonstrated to prevent hypoxia-induced cardiomyocyte damage by triggering endogenous cardioprotective cascades to mitigate myocardial damage. Herein, with the notion that OP can be conveniently applied anywhere, we sought to explore it as an alternative therapeutic intervention for preventing HH-induced myocarditis, remodeling, and arrhythmias.

Methods

OP intervention (6 cycles of 5 min occlusion with 200 mmHg for 5 min and 5 min reperfusion at 0 mmHg - applying to alternate hindlimb daily for 7 consecutive days) was performed, and its impact on cardiac electric activity, immunoregulation, myocardial remodeling, metabolic homeostasis, oxidative stress responses, and behavioral outcomes were assessed before and after exposure to HH in mice. In humans, before and after the application of OP intervention (6 cycles of 5 min occlusion with 130% of systolic pressure and 5 min reperfusion at 0 mmHg - applying to alternate upper limb daily for 6 consecutive days), all subjects were assessed by cardiopulmonary exercise testing (CPET).

Results

Comparing the outcomes of OP to AP intervention, we observed that similar to the latter, OP preserved cardiac electric activity, mitigated maladaptive myocardial remodeling, induced adaptive immunomodulation and metabolic homeostasis in the heart, enhanced antioxidant defenses, and conferred resistance against HH-induce anxiety-related behavior. Additionally, OP enhanced respiratory and oxygen-carrying capacity, metabolic homeostasis, and endurance in humans.

Conclusions

Overall, these findings demonstrate that OP is a potent alternative therapeutic intervention for preventing hypoxia-induced myocarditis, cardiac remodeling, arrhythmias, and cardiometabolic disorders and could potentially ameliorate the progression of other inflammatory, metabolic, and oxidative stress-related diseases.

Anti-hypoxic pharmacological effects of betelnut polyphenols

Areca catechu L. medicinal materials and their preparations are widely used in clinical practice. Betelnut polyphenol is one of the main chemical components with antioxidant, anti-inflammatory, and antibacterial effects. With continuous increase of high altitude activities, tissue oxidative damage caused by high altitude hypoxia seriously affects the ability to work, and the studies on anti-hypoxia drugs are particularly important. Recent studies have shown that betelnut polyphenols have protective effects on oxidative stress injury caused by hypoxia via improving blood gas index of hypoxic organism, increasing superoxide dismutase glutathione catalase activity, and scavenging excessive free radicals. The effects of betelnut polyphenols against hypoxia and oxidative damage protection suggest that betelnut polyphenols can be used as potential anti-hypoxia drugs and posses clinical prospects.

Salidroside Promotes Sensitization to Doxorubicin in Human Cancer Cells by Affecting the PI3K/Akt/HIF Signal Pathway and Inhibiting the Expression of Tumor-Resistance-Related Proteins

Salidroside (Sal), the major active constituent of Rhodiola rosea L., is considered as a potential pro-drug with various activities; however, its role in tumor therapy is not clear. Here, we demonstrated in vitro and in vivo that Sal enhanced the inhibitory activity of doxorubicin (DOX) in drug-resistant cancer cell lines. Our results showed that combination drug treatment (Sal and DOX) significantly decreased cell proliferation, migration, and motility. Besides biological validation, a luciferase-labeled animal tumor xenograft model and bioluminescence imaging (BLI) were applied for assessing the tumor progression. Sal combined with DOX inhibited the growth of HeLa-ADR-luc cells in vivo and downregulated the DOX-induced high expression of MDR1. Also, Sal downregulated the Bcl-2, MMP-2, MMP-9, PI3K, and AKT and upregulated BAX proteins. Sal demonstrated high safety and cardiac protection activity. We discovered that Sal enhances DOX sensitivity through the regulation of PI3K/Akt/HIF-1α and DOX-induced resistance pathways. Our results suggest that Sal could be a novel chemosensitization agent for the treatment of multi-drug-resistance tumors.

Insight into the Protective Effect of Salidroside against H2O2-Induced Injury in H9C2 Cells

Salidroside is the important active ingredient of Rhodiola species, which shows a wide range of pharmacological activities such as antioxidative stress, anti-inflammation, and antiliver fibrosis. In this paper, we aimed to study the protective effect and mechanism of salidroside against H2O2-induced oxidative damage in H9C2 cells by determining cell proliferation rate, intracellular reactive oxygen species (ROS) level, antioxidant enzyme activities, and the expression of apoptosis-related proteins. The results showed that salidroside significantly alleviated cell growth inhibition induced by H2O2 treatment in H9C2 cells, decreased the levels of intracellular ROS and malondialdehyde (MDA), and increased the activity of superoxide dismutase (SOD) and catalase (CAT); meanwhile, salidroside upregulated the expression of Bcl-2 while downregulated the expression of Bax, p53, and caspase-3 in H2O2-treated H9C2 cells. Furthermore, the antiapoptotic effect of salidroside was almost eliminated by the knockdown of Bcl-2. In the further exploration, the Bcl-2 expression was decreased by the p53 overexpression and increased by p53 knockdown in H2O2-treated H9C2 cells. Consequently, salidroside could protect H9C2 cells against H2O2-induced oxidative damage, and the underlying mechanism may be related to scavenging intracellular ROS, increasing the activities of intracellular antioxidant enzymes and inhibiting the expression of apoptosis-related proteins.

Histopathological, histochemical and biochemical postmortem changes in induced fatal hypothermia in rats

Reaching a postmortem diagnosis of hypothermia is challenging in forensic practice. Therefore, this study was conducted to detect the histopathological, histochemical and biochemical changes that occur in adult albino rats following exposure to induced fatal hypothermia. Twenty-four adult albino rats were divided into the negative control, moderate hypothermia, severe hypothermia and hypoxia groups. Rats in the control group were euthanized when those in the moderate hypothermic group died. Blood samples were collected via heart puncture, and the cerebrum, heart, suprarenal gland, kidney, liver and skeletal muscle were removed to investigate the biochemical, histochemical and histopathological changes. Postmortem assessment depicted significant changes in lipid peroxidation, represented by increased malondialdehyde levels in the studied organs of the rats in hypothermic and hypoxia groups. Histopathological examination of the rats’ organs revealed degeneration and necrosis in the hypothermia and hypoxia groups. Sections taken from the severe hypothermic rats revealed a loss of normal cardiac tissue architecture, necrotic changes in the pyramidal cells in the cerebral cortex, and massive necrosis, mainly in the tubules of the renal cortex and medulla. These findings suggest that histological changes might be used as biochemical markers for postmortem diagnosing of fatal hypothermia, particularly in severe hypothermic conditions.

Key points

Death by hypothermia is a serious public health problem worldwide.

Confirming a diagnosis and determining the cause of death in cases of hypothermia are among the most difficult practices in forensic medicine.

Death by hypothermia might be associated with structural abnormalities in various organs.

Studies using different tissue staining techniques will enable an overall illustration of the role of histopathological changes in body organs as indicators of hypothermia.

Salidroside Improves Chronic Stress Induced Depressive Symptoms Through Microglial Activation Suppression

Depression is a severe neurological disorder highly associated with chronic mental stress stimulation, which involves chronic inflammation and microglial activation in the central nervous system (CNS). Salidroside (SLDS) has been reported to exhibit anti-neuroinflammatory and protective properties on neurological diseases. However, the mechanism underlying the effect of SLDS on depressive symptoms has not been well elaborated. In the present study, the effects of SLDS on depressive behaviors and microglia activation in mice CNS were investigated. Behavioral tests, including Forced swimming test (FST), Open field test (OFT) and Morris water maze (MWM) revealed that SLDS treatment attenuated the depressive behaviors in stress mice. SLDS treatment significantly reduced the microglial immunoreactivity for both Iba-1 and CD68, characteristic of deleterious M1 phenotype in hippocampus of stress mice. Additionally, SLDS inhibited microglial activation involving the suppression of ERK1/2, P38 MAPK and p65 NF-κB activation and thus reduced the expression and release of neuroinflammatory cytokines in stress mice as well as in lipopolysaccharide (LPS)-induced primary microglia. Also, SLDS changed microglial morphology, attachment and reduced the phagocytic ability in LPS-induced primary microglia. The results demonstrated that SLDS treatment could improve the depressive symptoms caused by unpredictable chronic stress, indicating a potential therapeutic application of SLDS in depression treatment by interfering microglia-mediated neuroinflammation.