Isoginkgetin, a bioactive constituent from Ginkgo Biloba, protects against obesity-induced cardiomyopathy via enhancing Nrf2/ARE signaling

Effect and mechanism of Qing Gan Zi Shen decoction on heart damage induced by obesity and hypertension

ETHNOPHARMACOLOGICAL RELEVANCE

Qing Gan Zi Shen Decoction (QGZS) is a traditional Chinese formula. It has been extensively used for decades in the treatment of hypertension combined with metabolic diseases, but its cardioprotective effects and underlying mechanisms are poorly understood.

AIM OF THE STUDY

To explore the cardioprotective effects and potential mechanisms of QGZS in an animal model of obese hypertension.

MATERIALS AND METHODS

In this study, spontaneously hypertensive rats (SHRs) were utilized as an animal model to examine the effects of a high-fat diet and two concentrations of QGZS. Echocardiography, hematoxylin eosin (H&E) staining, and wheat germ agglutinin (WGA) staining were employed to assess the cardiac structure and function of the SHRs throughout a 16-week therapy period. Furthermore, Western blotting (WB) and immunofluorescence (IF) were employed to identify the levels of Nrf2 expression in the mitochondria, cytoplasm, and nucleus of the myocardium. Additionally, transmission electron microscopy and enzyme-linked immunosorbent assay (ELISA) were utilized to measure mitochondrial morphology and pro-inflammatory cytokine levels, respectively. Furthermore, Western blotting (WB), immunohistochemistry (IHC), and immunofluorescence (IF) techniques were employed to quantify the levels of marker proteins associated with myocardial fibrosis, cardiac inflammation, oxidative stress, and mitochondrial dysfunction.

RESULTS

QGZS inhibited weight gain and depressed systolic and mean arterial pressures in high-fat-fed SHRs. Echocardiographic results demonstrated that QGZS prevented the increase in left ventricular mass, restricted the growth of left ventricular diameter, and improved ejection fraction (EF), fractional shortening (FS), and the ratio of early diastolic peak velocity of transmitral flow (E) to late diastolic peak velocity (A) in high-fat-fed SHRs. This suggested that QGZS prevented ventricular remodeling and protected cardiac systolic and diastolic functions. H&E and WGA staining showed that QGZS improved cardiomyocyte disorders and restricted cardiomyocyte hypertrophy. The underlying mechanisms, QGZS attenuated the oxidative stress state, including reducing the generation of reactive oxygen species (ROS) in the myocardium, revitalizing the antioxidant enzyme system, and protecting mitochondrial function. Moreover, QGZS alleviated the pro-inflammatory state in high-fat-fed SHRs. What's more, QGZS significantly increased the expression level of Nrf2 in nuclei and mitochondria in rat heart tissues, exerting a proximate Nrf2 agonist effect.

CONCLUSIONS

QGZS exerted cardioprotective effects, in part due to its increasing expression of Nrf2 protein in the heart, which promoted Nrf2 nuclear expression.

Activation of sigma-1 receptor ameliorates sepsis-induced myocardial injury by mediating the Nrf2/HO1 signaling pathway to attenuate mitochondrial oxidative stress

BACKGROUND

Sepsis is a condition that triggers the release of large amounts of reactive oxygen species and inflammatory factors in the body, leading to myocardial injury and cardiovascular dysfunction - an important contributor to the high mortality rate associated with sepsis. Although it has been demonstrated that the sigma-1 receptor (S1R) is essential for preventing oxidative stress, its effectiveness in treating sepsis is yet unknown.

AIM

This study aimed to investigate the role and mechanisms of S1R activation in sepsis-induced myocardial injury.

METHODS

A model of sepsis-induced myocardial injury was constructed by performing cecum ligation and puncture(CLP) surgery on rats. Flv or BD1047 were intraperitoneally injected into rats for one consecutive week before performing CLP, and then intraperitoneally injected into the rats again 1 h after the surgery.The effects of Flv and BD1047 were detected by HE staining, immunofluorescence staining, IHC staining, echocardiography measurements,TUNEL, oxidative stress detection, TEM, flow cytometry and western blot. We further validated the mechanism in vitro using neonatal rat cardiomyocites and H9C2 cells.

RESULTS

S1R protein level was reduced in the hearts of septic rats, whereas administration of Flv, an S1R activator, ameliorated myocardial injury, mitochondrial oxidative stress, and pathological manifestations of sepsis. On the other hand, administration of the S1R inhibitor BD1047 exacerbated the mitochondrial oxidative stress, and apoptosis, as well as symptoms and pathological manifestations of sepsis. In addition, we found that up-regulation of S1R activated the Nrf2/HO1 signaling pathway and promoted nuclear translocation of Nrf2, which activated downstream proteins to generate antioxidant factors, such as HO1, in turn alleviating oxidative stress and countering myocardial damage.

CONCLUSION

By scavenging ROS accumulation and reducing mitochondrial oxidative stress via the Nrf2/HO1 signaling pathway, activation of S1R improves cardiac function, mitigates death of cardiomyocytes, and attenuates sepsis-induced myocardial injury.

Tussilagone inhibits osteoclastogenesis by modulating mitochondrial function and ROS production involved Nrf2 activation

Reactive Oxygen Species (ROS) play an essential role in the pathogenesis of osteoporosis mainly characterized by excessive osteoclasts (OCs) activity. OCs are rich in mitochondria for energy support, which is a major source of total ROS. Tussilagone (TSG), a natural Sesquiterpenes from the flower of Tussilago farfara, has plentiful beneficial pharmacological characteristics with anti-inflammatory and anti-oxidative activity, but its effects and mechanism in osteopathology are still unclear. In our study, we investigated the regulation of ROS generated from the mitochondria in OCs. We found that TSG inhibited OCs differentiation and bone resorption without any cytotoxicity. Mechanistically, TSG reduced RANKL-mediated total ROS level by down-regulating intracellular ROS production and mitochondrial function, leading to the suppression of NFATc1 transcription. We also found that nuclear factor erythroid 2-related factor 2 (Nrf2) could enhance ROS scavenging enzymes in response to RANKL-induced oxidative stress. Furthermore, TSG up-regulated the expression of Nrf2 by inhibiting its proteosomal degradation. Interestingly, Nrf2 deficiency reversed the suppressive effect of TSG on mitochondrial activity and ROS signaling in OCs. Consistent with this finding, TSG attenuated post-ovariectomy (OVX)- and lipopolysaccharide (LPS) induced bone loss by ameliorating osteoclastogenesis. Taken together, TSG has an anti-bone resorptive effect by modulating mitochondrial function and ROS production involved Nrf2 activation.

Beneficial effects of ginkgetin on improving nonalcoholic steatohepatitis characterized by bulk and single-cell RNA sequencing analysis

Background and aims: Nonalcoholic steatohepatitis (NASH) has become one of the major causes of cirrhosis and liver failure. However, there are currently no approved medications for managing NASH. Our study was designed to assess the effects of ginkgetin on NASH and the involved mechanisms. Methods: We constructed a mouse model of NASH by high-fat diet for 24 weeks. The effects of ginkgetin on NASH were evaluated by histological study, Western blot, and biochemical analysis. RNA Sequencing (RNA-Seq) analysis was used to investigate the alteration in gene expression and signaling pathways at bulk and single-cell levels. Results: Administration of ginkgetin resulted in a marked improvement in hepatic lipid accumulation, inflammation, and fibrosis in the NASH model. And these results were supported by bulk RNA-Seq analysis, in which the related signaling pathways and gene expression were markedly downregulated. Furthermore, single-cell RNA-Seq (scRNA-Seq) analysis revealed that the effects of ginkgetin on NASH were associated with the reprogramming of macrophages, hepatic stellate cells, and endothelial cells. Especially, ginkgetin induced a marked decrease in macrophages and a shift from pro-inflammatory to anti-inflammatory phenotype in NASH mice. And the NASH-associated macrophages (NAMs), which emerge during NASH, were also significantly downregulated by ginkgetin. Conclusion: Ginkgetin exhibits beneficial effects on improving NASH, supported by bulk and single-cell RNA-Seq. Our study may promote pharmacological therapy for NASH and raise the existent understanding of NASH.

DNA damage resulting from human endocrine disrupting chemical exposure: Genotoxicity, detection and dietary phytochemical intervention

In recent years, exposure to endocrine disrupting chemicals (EDCs) has posed an increasing threat to human health. EDCs are major risk factors in the occurrence and development of many diseases. Continuous DNA damage triggers severe pathogenic consequences, such as cancer. Beyond their effects on the endocrine system, EDCs genotoxicity is also worthy of attention, owing to the high accessibility and bioavailability of EDCs. This review investigates and summarizes nearly a decade of DNA damage studies on EDC exposure, including DNA damage mechanisms, detection methods, population marker analysis, and the application of dietary phytochemicals. The aims of this review are (1) to systematically summarize the genotoxic effects of environmental EDCs (2) to comprehensively summarize cutting-edge measurement methods, thus providing analytical solutions for studies on EDC exposure; and (3) to highlight critical data on the detoxification and repair effects of dietary phytochemicals. Dietary phytochemicals decrease genotoxicity by playing a major role in the detoxification system, and show potential therapeutic effects on human diseases caused by EDC exposure. This review may support research on environmental toxicology and alternative chemo-prevention for human EDC exposure.

Rivaroxaban Combined with Atorvastatin Inhibits Acute Pulmonary Embolism by Promoting the Expression of NRF2/NQO1

BACKGROUND

Atorvastatin and direct oral factor Xa inhibitors (for instance, rivaroxaban) are co-administrated in patients with atrial fibrillation. However, no studies have been conducted on the function of these two agents in acute pulmonary embolism (APE). Therefore, we investigated the effects of rivaroxaban + atorvastatin in rats with APE and explored the underlying mechanisms.

METHODS

Patients with APE were enrolled, and rats with APE were generated for different regimens. The mean pulmonary arterial pressure (mPAP), heart rate, and PaO₂ of APE patients and rats were measured. The plasma levels of oxidative stress- and inflammation-related factors were measured, and the expression of platelet activation markers (CD63 and CD62P) was detected. The proteins targeted by rivaroxaban and atorvastatin, the targets associated with APE, and the genes aberrantly expressed in rats with APE were intersected to obtain candidate factors.

RESULTS

Rivaroxaban + atorvastatin reduced mPAP and increased PaO₂ in patients and rats with APE. Rivaroxaban + atorvastatin repressed oxidative stress, inflammatory levels, and platelet activation during APE. NRF2 and NQO1 were increased in the lung of rats treated with rivaroxaban + atorvastatin. The therapeutic effect of the combination on APE rats was suppressed after NRF2 downregulation. NRF2 promoted the NQO1 transcription. NQO1 eliminated the inhibitory effect of sh-NRF2 on the combined therapy.

CONCLUSION

The alleviating effect of rivaroxaban + atorvastatin administration against APE correlates with NRF2/NQO1 expression.

Isoorientin ameliorates H2O2-induced apoptosis and oxidative stress in chondrocytes by regulating MAPK and PI3K/Akt pathways

Osteoarthritis (OA) is a chronic and complicated degenerative disease for which there is currently no effective treatment. Isoorientin (ISO) is a natural plant extract that has antioxidant activity and could be used to treat OA. However, due to a lack of research, it has not been widely used. In this study, we investigated the protective effects and molecular mechanisms of ISO on H₂O₂-induced chondrocytes, a widely used cell model for OA. Based on RNA-seq and bioinformatics, we discovered that ISO significantly increased the activity of chondrocytes induced by H₂O₂, which was associated with apoptosis and oxidative stress. Furthermore, the combination of ISO and H₂O₂ significantly reduced apoptosis and restored mitochondrial membrane potential (MMP), which may be achieved by inhibiting apoptosis and mitogen-activated protein kinase (MAPK) signaling pathways. Moreover, ISO increased superoxide dismutase (SOD), heme oxygenase 1 (HO-1) and quinone oxidoreductase 1 (NQO-1) and reduced malondialdehyde (MDA) levels. Finally, ISO inhibited H₂O₂-induced intracellular reactive oxygen species (ROS) in chondrocytes by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) and phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) signaling pathways. This study establishes a theoretical framework for ISO's ability to inhibit OA in vitro models.

Isoginkgetin-loaded reactive oxygen species scavenging nanoparticles ameliorate intervertebral disc degeneration via enhancing autophagy in nucleus pulposus cells

Excessive reactive oxygen species (ROS) in nucleus pulposus cells (NPCs) promote extracellular matrix (ECM) degradation and cellular inflammatory responses by activating a variety of cellular pathways, ultimately inducing cell apoptosis and leading to the development of low back pain. Here, we designed and fabricated an isoginkgetin-loaded ROS-responsive delivery system (IGK@SeNP) based on diselenide block copolymers. Successfully encapsulated IGK was released intelligently and rapidly in a microenvironment with high ROS levels in degenerative disc. Controlled-release IGK not only efficiently scavenged ROS from the intervertebral disc together with diselenide block copolymers but also effectively enhanced autophagy in NPCs to inhibit ECM degradation and cell apoptosis, and showed significant therapeutic effects in the rat intervertebral disc degeneration (IDD) model. Overall, the synergistic effects of IGK@SeNP in ROS scavenging and autophagy enhancement endowed it with an attractive therapeutic strategy for IDD treatment.