Myrtenol alleviates oxidative stress and inflammation in diabetic pregnant rats via TLR4/MyD88/NF-κB signaling pathway

Myrtenol-loaded niosomes can prevent lung ischemia-reperfusion injury model in rats by balancing the Nrf2/Keap1 and NF-κB signaling pathways

Lung Ischemia-reperfusion injury (LIRI) is a risk during lung transplantation that can cause acute lung injury and organ failure. In LIRI, the NF-E2-related factor 2(Nrf2)/ Kelch-like ECH-associated protein 1 (Keap1) signaling pathway and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway are two major pathways involved in regulating oxidative stress and inflammation, respectively. Myrtenol, a natural compound with anti-inflammatory and antioxidant properties, has potential protective effects against IRI. This study aimed to explore the impact of myrtenol encapsulated within niosomes on the prevention of LIRI and examine the role of the two pathways mentioned in this process. Wistar rats were segregated into four groups. Animals received the myrtenol (MN) (32 mg/kg) or vehicle through daily inhalation for a week before LIRI. Expression of IκB, p-IκB, Nrf2, Keap1, Heme Oxygenase-1(HO-1), NF-κB signaling proteins, reactive oxygen species (ROS) level, caspase-3 expression, arterial blood gases, lung edema, and histopathological indices were assessed. Niosomal myrtenol significantly reduced lung edema, ROS, Keap1, p-IκB, NF-kB, Caspase-3, PaCO2 (the carbon dioxide pressure in arterial blood), and histopathological indices. Additionally, the expression of IκB, Nrf2, HO-1, and PaO2 (the oxygen pressure in arterial blood) increased significantly in the pretreated group compared to the IR group. Overall, inhalation of the niosomal myrtenol protects against lung ischemia-reperfusion injury, presumably through the balance between Nrf2/Keap1 and NF-κB pathways. The findings suggest that the niosomal form of myrtenol may be a potential candidate for developing new drugs to prevent and treat LIR damage.

Baicalein inhibits NLRP3 inflammasome activation and mitigates placental inflammation and oxidative stress in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a common metabolic disorder during pregnancy characterized by glucose intolerance, which poses risks to both maternal and fetal health. Baicalein, a flavonoid derived from the roots of Scutellaria baicalensis Georgi, exhibits various biological functions and has been implicated in the modulation of several diseases. However, the regulatory effects and underlying mechanisms of Baicalein in GDM progression remain unclear. In this study, we found that Baicalein ameliorates metabolic disturbances in GDM mice by improving glucose tolerance, insulin sensitivity, fasting blood glucose levels, and plasma insulin levels. Additionally, Baicalein treatment positively impacted litter size and birth weight. GDM mice exhibited increased inflammation and oxidative stress, which were mitigated following Baicalein administration (40 mg/kg). Furthermore, elevated protein levels of NLRP3, IL-1β, and IL-18 observed in GDM mice were reduced by Baicalein treatment. In conclusion, Baicalein inhibits the NLRP3 inflammasome and alleviates placental inflammation and oxidative stress associated with GDM. These findings provide valuable insights into the potential therapeutic role of Baicalein in managing GDM.

Intermittent mild cold acclimation ameliorates intestinal inflammation and immune dysfunction in acute cold-stressed broilers by regulating the TLR4/MyD88/NF-κB pathway

To investigate the potential protective effect of prior cold stimulation on broiler intestine induced by acute cold stress (ACS). A total of 384 one-day-old broilers were divided into control (CON), ACS, cold stimulation Ⅰ (CS3+ACS), and cold stimulation Ⅱ (CS9+ACS) groups. Broilers in CON and ACS groups were reared normally, and birds in CS3+ACS and CS9+ACS groups were reared at 3℃ and 9℃ below CON group for 5 h, respectively, on alternate days from d 15 to 35. Broilers in ACS, CS3+ACS, and CS9+ACS groups were subjected to 10℃ for 24 h on d 43. Eventually, small intestine tissues were collected for histopathological observation and indexes detection. The results showed that intestinal tissues in all ACS-broilers exhibited inflammatory cell infiltrates, microvilli disruption, reduced villus length in jejunum and increased crypt depth in jejunum and ileum. Whereas these phenomena were relatively light in CS3+ACS group. Compared to CON group, mRNA expression of the TLR4/MyD88/NF-κB pathway-related genes (TLR4, MyD88, NF-κBp65, COX-2, iNOS, PTGEs, TNF-α), Th1/Th17-derived cytokines (IL-1β, IL-2, IL-8, IL-12, IFN-γ, IL-17), and HSPs (HSP40, HSP60, HSP70, HSP90) was upregulated (P < 0.05), and that of Th2-deviated cytokines (IL-4, IL-6, IL-10, IL-13) and IκBα was downregulated (P < 0.05) in small intestine in almost all ACS-broilers. Compared to ACS group, mRNA expression of most of the TLR4/MyD88/NF-κB pathway-related genes, Th1/Th17-derived cytokines, and HSPs was downregulated and that of Th2-derived cytokines was upregulated in CS3+ACS group (P < 0.05). Protein expression levels of TLR4, MyD88, p-p65/p65, p-IκBα/IκBα, IKK, TNF-α, IL-1β, IL-10, and HSPs were similar to their mRNA expression. The concentration of sIgA and activities of CAT, SOD, and GSH-px were decreased and MDA and H2O2 were increased in ACS and CS9+ACS groups compared to CON group (P < 0.05). Therefore, cold stress caused oxidative stress and inflammation, leading to gut immune dysfunction; while mild cold stimulation at 3℃ below normal rearing temperature alleviated cold stress-induced intestinal injure and dysfunction by modulating the TLR4/MyD88/NF-κB pathway in broilers.

ATP5me alleviates high glucose-induced myocardial cell injury

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with adverse myocardial remodeling and impaired cardiac function of fetus. Nevertheless, specific molecular mechanisms underlying type 1 GDM-induced fetal myocardial injury remain unknown. Therefore, this study proposes to identify possible molecular mechanisms using RNA-seq.

METHODS

A rat type 1 GDM model was developed using streptozotocin (STZ) (25 and 50 mg/kg), and weight and glucose tolerance of maternal and offspring were evaluated. Changes in markers of myocardial injury and oxidative stress identified by ELISA and biochemical kits in offspring hearts. Identification of differentially expressed mRNAs (DE-mRNAs) associated with myocardial injury in type 1 GDM offspring using RNA-seq. Proliferation, apoptosis, and oxidative stress were assessed in high glucose-induced H9C2 cells after exogenously modulating ATP Synthase Membrane Subunit E (ATP5me).

RESULTS

Maternal weight, glucose and glucose tolerance, and fetal weight and heart weight were reduced in the type 1 GDM model, especially in 50 mg/kg STZ-induced. Increased of creatine kinase-MB (CK-MB), cardiac troponin T (cTnT), hypersensitive C-reactive protein (hs-CRP), reactive oxygen species (ROS) and malondialdehyde (MDA) and decreased of superoxide dismutase (SOD) were observed in type 1 GDM offspring hearts. type 1 GDM offspring hearts exhibited disorganized cardiomyocytes with enlarged gaps, broken myocardial fibers, erythrocyte accumulation and inflammatory infiltration. RNA-seq identified 462 DE-mRNAs in type 1 GDM offspring hearts, which mainly regulate immunity, redox reactions, and cellular communication. Atp5me was under-expressed in type 1 GDM offspring hearts, and high glucose decreased Atp5me expression in H9C2 cells. Overexpressing Atp5me alleviated high glucose-induced decrease in proliferation, mitochondrial membrane potential, BCL2 and SOD, and increase in apoptosis, MDA, ROS, c-Caspase-3, and BAX in H9C2 cells.

CONCLUSION

This study first demonstrated that ATP5me attenuated type 1 GDM-induced fetal myocardial injury. This provides a possible molecular mechanism for the treatment of type 1 GDM-induced fetal myocardial injury.

Plant Monoterpenes and Essential Oils as Potential Anti-Ageing Agents: Insights from Preclinical Data

Ageing is a natural process characterized by a time-dependent decline of physiological integrity that compromises functionality and inevitably leads to death. This decline is also quite relevant in major human pathologies, being a primary risk factor in neurodegenerative diseases, metabolic disorders, cardiovascular diseases and musculoskeletal disorders. Bearing this in mind, it is not surprising that research aiming at improving human health during this process has burst in the last decades. Importantly, major hallmarks of the ageing process and phenotype have been identified, this knowledge being quite relevant for future studies towards the identification of putative pharmaceutical targets, enabling the development of preventive/therapeutic strategies to improve health and longevity. In this context, aromatic plants have emerged as a source of potential bioactive volatile molecules, mainly monoterpenes, with many studies referring to their anti-ageing potential. Nevertheless, an integrated review on the current knowledge is lacking, with several research approaches studying isolated ageing hallmarks or referring to an overall anti-ageing effect, without depicting possible mechanisms of action. Herein, we aim to provide an updated systematization of the bioactive potential of volatile monoterpenes on recently proposed ageing hallmarks, and highlight the main mechanisms of action already identified, as well as possible chemical entity-activity relations. By gathering and categorizing the available scattered information, we also aim to identify important research gaps that could help pave the way for future research in the field.

Preparation and Evaluation of Preventive Effects of Inhalational and Intraperitoneal Injection of Myrtenol Loaded Nano-Niosomes on Lung Ischemia-Reperfusion Injury in Rats

INTRODUCTION

Ischemia-reperfusion injury (IRI) is directly related to forming reactive oxygen species, endothelial cell injury, increased vascular permeability, and the activation of neutrophils and cytokines. Niosomes are nanocarriers and an essential part of drug delivery systems. We aimed to investigate the effects of myrtenol's inhaled and intraperitoneal niosomal form, compared to its simple form, on lung ischemia reperfusion injury (LIRI).

MATERIAL AND METHOD

Wistar rats were divided into ten groups. Simple and niosomal forms of myrtenol were inhaled or intraperitoneally injected daily for one week prior to LIRI. We evaluated oxidative stress, apoptotic, and inflammatory indices, nitric oxide, inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and histopathological indices.

RESULTS

Pretreatment with simple and niosomal forms of myrtenol significantly inhibited the indices of pulmonary edema, pro-inflammatory cytokines and proteins, oxidant agents, nitric oxide, iNOS, apoptotic proteins, congestion of capillaries, neutrophil infiltration, and bleeding in the alveoli. Furthermore, myrtenol increased anti-inflammatory cytokines, anti-oxidants agents, eNOS, anti-apoptotic proteins and the survival time of animals. The niosomal form of myrtenol showed a more ameliorative effect than its simple form.

CONCLUSION

The results showed the superior protective effect of the inhalation of myrtenol niosomal form against LIRI compared to its simple form and systemic use.

A systematic review on anti-diabetic plant essential oil compounds: Dietary sources, effects, molecular mechanisms, and safety

Type 2 diabetes mellitus (T2DM) is a multifaceted metabolic syndrome defined through the dysfunction of pancreatic β-cells driven by a confluence of genetic and environmental elements. Insulin resistance, mediated by interleukins and other inflammatory elements, is one of the key factors contributing to the progression of T2DM. Many essential oils derived from dietary plants are beneficial against various chronic diseases. We reviewed the anti-diabetic properties of dietary plant-derived essential oil compounds, with a focus on their molecular mechanisms by modulating specific signaling pathways and other critical inflammatory mediators involved in insulin resistance. High-quality literature published in the last 12 years, from 2010 to 2022, was collected from the Scopus, Web of Science, PubMed, and Embase databases using the search terms "dietary plants," "essential oils," "anti-diabetic," "insulin resistance," "antihyperglycemic," "T2DM," "anti-diabetic essential oils," and anti-diabetic mechanism." According to the results, the essential oil compounds, including cinnamaldehyde, carvacrol, zingerone, sclareol, zerumbone, myrtenol, thujone, geraniol, citral, eugenol, thymoquinone, thymol, citronellol, α-terpineol, and linalool have been demonstrated to contain strong anti-diabetic effects via modulating various signal transduction pathways linked to glucose metabolism. Additionally, in diabetes-related animal models, they can also considerably reduce the expression of TNF-α, IL-1β, IL-4, IL-6, iNOS, and COX-2. The main signaling molecules regulated by these compounds include AMPK, GLUT4, Caspase-3, PPARγ, PPARα, NF-κB, p-IκBα, MyD88, MCP-1, SREBP-1c, AGEs, RAGE, VEGF, Nrf2/HO-1, and SIRT-1. They can also significantly inhibit the generation of TBARS and MDA, reduce oxidative stress, increase insulin levels, adiponectin, and glycoprotein enzymes, boost antioxidant enzymes like SOD, CAT, and GPx, as well as reduce glutathione and vital glycolytic enzymes. Besides, they can significantly lower the levels of liver enzymes and lipid profile markers. Moreover, most essential oil compounds are generally safe based on animal studies. In conclusion, dietary plant-derived essential oil compounds have potential anti-diabetic effects by influencing different signaling pathways and molecular targets linked to glucose metabolism, and should be safe and beneficial against diabetes and related complications.

The Study of Hypoglycemic Activity of 7-Terpenylcoumarins

Natural and synthetic coumarins are often considered privileged scaffolds for obtaining pharmacological agents with hypoglycemic activity. Chemical modification of coumarins often leads to antidiabetic agents with greater efficacy. In the present work, twenty monoterpene-substituted 7-hydroxycoumarins were synthesized. A new approach using the Mitsunobu reaction was shown to be effective for the synthesis of target compounds. All of the synthesized compounds were evaluated in an oral glucose tolerance test, and two of them containing geranyl and (-)-myrtenyl substituents showed in vivo hypoglycemic action. A possible mechanism of action of these compounds may include inhibition of DPP IV, which was proved in an in vitro test.

miR-340-5p Alleviates Oxidative Stress Injury by Targeting MyD88 in Sepsis-Induced Cardiomyopathy

Background

Sepsis-induced cardiomyopathy (SIC) is a sort of severe disease in the intensive care unit. This research focuses on exploring the influence of miR-340-5p on SIC and its specific mechanism.

Methods

Mice were administered with lipopolysaccharide (LPS) to construct a SIC animal model. Mice were intramyocardially injected with Adenoassociated Virus- (AAV-) 9 containing the miR-340-5p precursor to make the miR-340-5p overexpression in the myocardium. The expression level of myocardial miR-340-5p was evaluated by qRT-PCR. The cardiac function was measured by echocardiography, the myocardial morphology was observed by hematoxylin-eosin (HE) staining, and the oxidative stress level was detected by 4-hydroxynonenal (4-HNE) immunohistochemical staining and malondialdehyde (MDA) assay in mice. The cells were pretreated with miR-340-5p mimic, mimic-NC, miR-340-5p inhibitor, inhibitor-NC, MyD88 siRNA, or si-NC and then administered with LPS or PBS. The cell viability was measured with the CCK-8 assay. The level of intracellular oxidative stress was evaluated using reactive oxygen species (ROS), MDA, and glutathione (GSH) detection. The MyD88 level was assessed via Western blotting analysis. The interaction of miR-340-5p with the MyD88 mRNA was confirmed via dual-luciferase reporter assay and RNA pull-down assay.

Results

The miR-340-5p overexpression partially alleviated the increase of the MyD88 level, impairment of cardiac function, and oxidative stress injury in the SIC animal model. In the SIC cell model, miR-340-5p mimic pretreatment partially relieved oxidative stress injury, while the miR-340-5p inhibitor had the opposite effect. Besides, the miR-340-5p mimic and inhibitor could reduce and further increase the MyD88 level in the SIC cell model, respectively. Dual-luciferase reporter and RNA pull-down experiments confirmed the interaction between the MyD88 mRNA and miR-340-5p. Finally, it was found that MyD88 siRNA pretreatment also partially alleviates the oxidative stress injury in the SIC cell model.

Conclusion

In sum, our study demonstrated that miR-340-5p can improve myocardial oxidative stress injury by targeting MyD88 in SIC.