Geraniol improves endothelial function by inhibiting NOX-2 derived oxidative stress in high fat diet fed mice

Atractylodes macrocephala Rhizoma alleviates blood hyperviscosity induced by high-fat, high-sugar, and high-salt diet by inhibiting gut-liver inflammation and fibrinogen synthesis

ETHNOPHARMACOLOGICAL RELEVANCE

Unhealthy dietary patterns and lifestyle changes have been linked to increased blood viscosity, which is recognized as an important pathogenic factor in cardiovascular and cerebrovascular diseases. The underlying mechanism may involve chronic inflammation resulting from intestinal barrier disruption induced by unhealthy diets. The rhizome of Atractylodes macrocephala Koidz. (Called Baizhu in China), is a well-used "spleen-reinforcing" traditional Chinese medicinal herb used for thousands of years. Previous research has demonstrated its multiple gastrointestinal health benefits and its ability to regulate metabolic disorders. However, the effects of Baizhu on blood hyperviscosity induced by long-term unhealthy diets remain unclear.

AIM OF THE STUDY

This study aimed to investigate the effects of the aqueous extract of Baizhu on blood hyperviscosity induced by unhealthy diet and to explore the possible mechanisms.

MATERIALS AND METHODS

The blood hyperviscosity model in SD rats was established utilizing a high-fat, high-sugar, and high-salt diet (HFSSD). Subsequently, the rats underwent a twelve-week intervention with varying doses of Baizhu and a positive control. To evaluate the efficacy of Baizhu on blood hyperviscosity in model rats, we measured behavioral index, hemorheological parameters, inflammatory cytokines, hematology, adhesion molecules, as well as biochemical indicators in serum and liver. We also assessed the pathological states of the colon and liver. Furthermore, Western blotting, ELISA, IHC, and qRT-PCR were used to determine the effect of Baizhu on the IL-6/STAT3/ESRRG signaling pathway and FIB synthesis.

RESULTS

The intervention of Baizhu showed evident attenuating effects on blood viscosity and microcirculation disorders, and exhibit the capacity to moderately modulate parameters including grip, autonomous activities, vertigo time, TC, TG, LDL-c, inflammatory factors, adhesion factors, hematological indicators, etc. At the same time, it reduces liver lipid droplet deposition, restores intestinal integrity, and lowers LPS level in the serum. Subsequent experimental results showed that Baizhu downregulated the expression of TLR4 and NF-κB in colon tissue, as well as the expression of IL-6, TLR4, p-JAK2, p-STAT3, and ESRRG in liver tissue. Finally, we also found that Baizhu could regulate the levels of FIB in plasma and liver.

CONCLUSION

Baizhu protects HFSSD-induced rats from blood hyperviscosity, likely through repairing the intestinal barrier and inhibiting LPS/TLR4-associated liver inflammatory activation, thus suppressing FIB synthesis through the downregulation of IL-6/STAT3/ESRRG pathway.

Targeting Insulin Resistance, Reactive Oxygen Species, Inflammation, Programmed Cell Death, ER Stress, and Mitochondrial Dysfunction for the Therapeutic Prevention of Free Fatty Acid-Induced Vascular Endothelial Lipotoxicity

Excessive intake of free fatty acids (FFAs), especially saturated fatty acids, can lead to atherosclerosis and increase the incidence of cardiovascular diseases. FFAs also contribute to obesity, hyperlipidemia, and nonalcoholic fatty liver disease. Palmitic acid (PA) is human plasma's most abundant saturated fatty acid. It is often used to study the toxicity caused by free fatty acids in different organs, including vascular lipotoxicity. Fatty acid overload induces endothelial dysfunction through various molecular mechanisms. Endothelial dysfunction alters vascular homeostasis by reducing vasodilation and increasing proinflammatory and prothrombotic states. It is also linked to atherosclerosis, which leads to coronary artery disease, peripheral artery disease, and stroke. In this review, we summarize the latest studies, revealing the molecular mechanism of free fatty acid-induced vascular dysfunction, targeting insulin resistance, reactive oxygen species, inflammation, programmed cell death, ER stress, and mitochondrial dysfunction. Meanwhile, this review provides new strategies and perspectives for preventing and reducing the impact of cardiovascular diseases on human health through the relevant targeting molecular mechanism.

Unlocking the therapeutic potential of Geraniol: an alternative perspective for metabolic disease management

ETHNOPHARMACOLOGICAL RELEVANCE

Natural substance geraniol has anti-inflammatory and antioxidant qualities. It may be used to treat metabolic diseases such as diabetes, obesity, and cardiovascular illnesses. Innovations in nanoformulations enhance geraniol's absorption, stability, and targeted distribution, augmenting its therapeutic effectiveness and mitigating side effects, despite the limits of traditional treatment.

AIM OF THE REVIEW

The therapeutic potential of geraniol in the management of metabolic disorders such as diabetes, obesity, neuroinflammation, and cardiovascular disease is examined in this review. It highlights the anti-inflammatory, antioxidant, and lipid-lowering qualities of geraniol as well as the potential for nanoformulations to increase bioavailability and therapeutic efficacy.

MATERIALS AND METHODS

A collection of pertinent research articles about the potential of geraniol in metabolic illnesses, including obesity, type 2 diabetes, as well as cardiovascular diseases, was compiled from PubMed, Scopus, and Google Scholar. Terms such as "metabolic syndrome," "antioxidant," "anti-inflammatory," "geraniol," and "nanoformulations" were employed. Google Patents were also examined in order to offer insights into current and upcoming research.

RESULTS

The potential of geraniol to treat metabolic disorders, including obesity, diabetes, hyperlipidemia, and cardiovascular illnesses, is thoroughly reviewed in this article. Recent research has demonstrated the lipid-lowering, antioxidant, and anti-inflammatory properties of geraniol as well as its ability to improve endothelial function and reduce oxidative stress in preclinical animals. The paper delves into the various nanoformulations, including liposomes, nanoparticles, and nanoemulsions, which enhance geraniol's therapeutic efficacy and bioavailability, making it a viable option for managing metabolic syndrome.

CONCLUSION

The antioxidant, anti-inflammatory, and lipid-lowering qualities of geraniol make it a promising treatment for metabolic diseases. Its bioavailability along with therapeutic efficacy are increased by nanoformulations, which makes it a compelling option for the treatment of conditions such as neuroinflammation, diabetes, and obesity.

Copper homeostasis and copper-induced cell death： Novel targeting for intervention in the pathogenesis of vascular aging

Copper-induced cell death, also known as cuproptosis, is distinct from other types of cell death such as apoptosis, necrosis, and ferroptosis. It can trigger the accumulation of lethal reactive oxygen species, leading to the onset and progression of aging. The significant increases in copper ion levels in the aging populations confirm a close relationship between copper homeostasis and vascular aging. On the other hand, vascular aging is also closely related to the occurrence of various cardiovascular diseases throughout the aging process. However, the specific causes of vascular aging are not clear, and different living environments and stress patterns can lead to individualized vascular aging. By exploring the correlations between copper-induced cell death and vascular aging, we can gain a novel perspective on the pathogenesis of vascular aging and enhance the prognosis of atherosclerosis. This article aims to provide a comprehensive review of the impacts of copper homeostasis on vascular aging, including their effects on endothelial cells, smooth muscle cells, oxidative stress, ferroptosis, intestinal flora, and other related factors. Furthermore, we intend to discuss potential strategies involving cuproptosis and provide new insights for copper-related vascular aging.

The potential role of plant secondary metabolites on antifungal and immunomodulatory effect

With the widespread use of antibiotic drugs worldwide and the global increase in the number of immunodeficient patients, fungal infections have become a serious threat to global public health security. Moreover, the evolution of fungal resistance to existing antifungal drugs is on the rise. To address these issues, the development of new antifungal drugs or fungal inhibitors needs to be targeted urgently. Plant secondary metabolites are characterized by a wide variety of chemical structures, low price, high availability, high antimicrobial activity, and few side effects. Therefore, plant secondary metabolites may be important resources for the identification and development of novel antifungal drugs. However, there are few studies to summarize those contents. In this review, the antifungal modes of action of plant secondary metabolites toward different types of fungi and fungal infections are covered, as well as highlighting immunomodulatory effects on the human body. This review of the literature should lay the foundation for research into new antifungal drugs and the discovery of new targets. KEY POINTS: • Immunocompromised patients who are infected the drug-resistant fungi are increasing. • Plant secondary metabolites toward various fungal targets are covered. • Plant secondary metabolites with immunomodulatory effect are verified in vivo.

Natural Monoterpenes as Potential Therapeutic Agents against Atherosclerosis

Traditional herbal medicines based on natural products play a pivotal role in preventing and managing atherosclerotic diseases, which are among the leading causes of death globally. Monoterpenes are a large class of naturally occurring compounds commonly found in many aromatic and medicinal plants. Emerging evidence has shown that monoterpenes have many biological properties, including cardioprotective effects. Remarkably, an increasing number of studies have demonstrated the therapeutic potential of natural monoterpenes to protect against the pathogenesis of atherosclerosis. These findings shed light on developing novel effective antiatherogenic drugs from these compounds. Herein, we provide an overview of natural monoterpenes' effects on atherogenesis and the underlying mechanisms. Monoterpenes have pleiotropic and multitargeted pharmacological properties by interacting with various cell types and intracellular molecular pathways involved in atherogenesis. These properties confer remarkable advantages in managing atherosclerosis, which has been recognized as a multifaceted vascular disease. We also discuss limitations in the potential clinical application of monoterpenes as therapeutic agents against atherosclerosis. We propose perspectives to give new insights into future preclinical research and clinical practice regarding natural monoterpenes.

Geraniol and β-citronellol participate in the vasorelaxant effects of Rosa damascena Miller essential oil on the rat thoracic aorta

AIM

This study aimed to investigate the vasoactive effects of Rosa damascena Miller essential oil and its major components, geraniol and β-citronellol, on the rat thoracic aorta.

METHODS

Isolated tissue bath model and Wistar rats were used to perform the experiments. Two-fold increasing concentrations (20-160 μg/mL) of rose oil were administered to determine its vasoactive effects. Submaximal contractions were induced by PE or KCl in both endothelium-intact and -denuded segments. Time-matched control groups were also formed. To evaluate the role of geraniol and β-citronellol, concentrations in the range of 0.4-3.2 μg/mL and 0.8-6.4 μg/mL were applied respectively. The statistical significance level was considered as p < 0.05.

RESULTS

All doses of rose oil applied led to vasorelaxation in thoracic aortas precontracted with PE. In precontracted thoracic aortas with KCl, the significant effect of rose oil persisted, albeit slightly diminished. When the endothelium was removed, the relaxant effect of rose oil was partially reduced, but still significant. Besides, although geraniol relaxed aortic segments at all concentrations (0.4 to 3.2 μg/mL), β-citronellol caused vasorelaxation at doses of 1.6, 3.2, and 6.4 μg/mL.

CONCLUSION

In conclusion, the first findings were obtained that rose oil can cause a vasorelaxant effect in a concentration-dependent manner in rat thoracic aorta. This effect substantially persisted in vascular segments without endothelium or precontracted with KCl. It was further shown for the first time that geraniol and β-citronellol exert vasodilatory effects on the rat thoracic aorta. These results suggest that rose oil exhibits its vasorelaxant effect through geraniol and β-citronellol.

Genome Sequencing of Amomum tsao-ko Provides Novel Insight Into Its Volatile Component Biosynthesis

As an important economic and medicinal crop, Amomum tsao-ko is rich in volatile oils and widely used in food additives, essential oils, and traditional Chinese medicine. However, the lack of the genome remains a limiting factor for understanding its medicinal properties at the molecular level. Here, based on 288.72 Gb of PacBio long reads and 105.45 Gb of Illumina paired-end short reads, we assembled a draft genome for A. tsao-ko (2.70 Gb in size, contig N50 of 2.45 Mb). Approximately 90.07% of the predicted genes were annotated in public databases. Based on comparative genomic analysis, genes involved in secondary metabolite biosynthesis, flavonoid metabolism, and terpenoid biosynthesis showed significant expansion. Notably, the DXS, GGPPS, and CYP450 genes, which participate in rate-limiting steps for terpenoid backbone biosynthesis and modification, may form the genetic basis for essential oil formation in A. tsao-ko. The assembled A. tsao-ko draft genome provides a valuable genetic resource for understanding the unique features of this plant and for further evolutionary and agronomic studies of Zingiberaceae species.

Astragaloside IV prevents endothelial dysfunction by improving oxidative stress in streptozotocin-induced diabetic mouse aortas

Oxidative stress serves a role in endothelial dysfunction exhibited by patients with diabetes mellitus. Astragaloside IV (AS-IV) is a major active ingredient of Radix Astragali, which is considered to exhibit vasoprotective effects through unknown mechanisms. Thus, the current study was performed to investigate the protective effects of AS-IV in streptozotocin (STZ)-induced endothelial dysfunction and to explore whether antioxidant mechanisms were involved. The protective effects of AS-IV on the endothelium-dependent relaxation and contraction of aortic rings were determined by isometric tension recordings. NADPH subunits and endothelial nitric oxide synthase (eNOS) expression was identified via western blotting. Superoxide dismutase and malondialdehyde levels were assayed using ELISA. Furthermore, the generation of reactive oxygen species (ROS) and nitric oxide (NO) was detected via dihydroethidium and 4,5-diaminofluorescein diacetate staining, respectively. The results revealed that STZ-injected mice exhibited increased aortic endothelium-dependent vasoconstriction and decreased vasorelaxation to acetylcholine. However, AS-IV treatment reversed these effects. N^G-nitro-L-arginine was subsequently used to completely inhibit impaired relaxation. Accordingly, impaired NO generation was restored following AS-IV treatment by increasing eNOS phosphorylation levels. Furthermore, ROS formation was also depressed following AS-IV treatment compared with that in STZ-injected mice. AS-IV also decreased the expression of various NADPH subunits, including human neutrophil cytochrome b light chain, neutrophil cytosolic factor 1, NADPH oxidase (NOX)2, NOX4 and Rac-1. The results of the current study may provide novel evidence that diabetes-induced vascular injury arises from either the inhibition of eNOS or the activation of NOX-derived ROS generation. In addition, the results warrant further investigation into the application of AS-IV treatment, leading to the improvement of oxidative stress, in patients with diabetes exhibiting endothelial dysfunction.

Juglanin suppresses oscillatory shear stress-induced endothelial dysfunction: An implication in atherosclerosis

INTRODUCTION

Atherosclerosis is characterized by endothelial cell dysfunction followed by lesion formation, arterial stenosis, potentially arterial occlusion, and severe outcomes. Novel treatments to slow or prevent the progression of the disease are of considerable clinical value. In the present study, we investigated the potential anti-atherosclerotic effects of the natural product juglanin in oscillatory shear stress (OSS) exposed endothelial cells.

METHODS

Human aortic endothelial cells (HAECs) were exposed to OSS generated by a micro fluidal Teflon cone at 1 Hz frequency cycles (±5 dyn/cm²) in the presence or absence of 2.5 and 5 μM juglanin for 24 h. The expression levels of inflammatory factors and vascular adhesion molecules were evaluated using qRT-PCR, Western Blot, and ELISA. DHE assay was used to detect the production of ROS. The monocytic THP-1 cells were labeled with calcein-AM and incubated with HAECs for adhesion assay.

RESULTS

Juglanin reduces OSS-induced oxidative stress by reducing the production of ROS through downregulation of NOX-2 and rescuing OSS-induced reduced expression of eNOS. Juglanin also inhibits the inflammatory response by suppressing OSS-induced expressions of IL-1β, MCP-1, and HMGB1. Using THP-1 monocytes, we show that juglanin reduces the attachment of monocytes to endothelial cells by inhibiting the expression of VCAM-1 and E-selectin. Moreover, Juglanin rescues OSS-reduced expression of atheroprotective transcriptional factor KLF2.

CONCLUSIONS

Our findings indicate that juglanin protects against various atheroprone OSS-induced endothelial dysfunction. Juglanin has potential implication as a candidate for vascular intervention of atherosclerosis.

The effect of some natural antioxidants against cisplatin-induced neurotoxicity in rats: behavioral testing

Background

Cisplatin (CP) is a common antineoplastic agent widely used to treat a broad spectrum of cancers. However, its usage for cancer treatment was restricted due to various side effects such as neurotoxicity, nephrotoxicity, hepatotoxicity and ototoxicity. Neurotoxicity in patients who have undergone a complete course of chemotherapy is clinically evident. CP administration caused problems in rats with memory and learning.

Methods

The effect of combination of CP with either thymoquinone (TQ) or geraniol (Ger) on cell viability of human breast cancer cells (MCF-7) was detected by MTT assay. Forty male Wistar albino rats, healthy and adult, were divided into four groups: normal control, CP-treated group, CP + TQ-treated group and CP + Ger-treated group.

Results

Our results demonstrated that prophylactic treatment with either TQ or Ger plus CP enhanced the anticancer effect of CP in MCF-7 cell line. In vivo study showed that CP-treated rats had higher depressives like behavior in open field and Morris water maze test while prophylactic treatment with either TQ or Ger and CP significantly enhanced the performance of depressive-like behavior. Also, histopathological evaluation of brain tissues proved the neurotoxic effect of CP and the possible protective activity of either TQ or Ger.

Conclusion

The findings of the present work revealed that TQ or Ger along with CP may enhance the antitumor effect of CP. Also, spontaneous administration of CP with either TQ or Ger as natural antioxidants may prevent CP-induced neurotoxicity in rats through diminishing the memory and learning impairment.

Oxidative stress induced by palmitic acid modulates KCa2.3 channels in vascular endothelium

Elevated plasma free fatty acids level has been implicated in the development of insulin resistance, inflammation, and endothelial dysfunction in diabetic and nondiabetic individuals. However, the underlying mechanisms still remain to be defined. Herein, we investigated the effect of palmitic acid (PA), the most abundant saturated fatty acid in the human body, on small-conductance Ca²⁺-activated potassium channels (K_Ca2.3)-mediated relaxation in rodent resistance arteries and the underlying molecular mechanism. The effect of PA on K_Ca2.3 in endothelium was evaluated using real-time PCR, Western blotting, whole-cell patch voltage-clamp, wire and pressure myograph system, and reactive oxygen species (ROS) were measured by using dihydroethidium and 2', 7'-dichlorofluorescein diacetate. K_Ca2.3-mediated vasodilatation responses to acetylcholine and NS309 (agonist of K_Ca2.3 and K_Ca3.1) were impaired by incubation of normal mesenteric arteries with 100 μM PA for 24 h. In cultured human umbilical vein endothelial cells (HUVECs), PA decreased K_Ca2.3 current and expression at mRNA and protein levels. Incubation with the NADPH oxidase (Nox) inhibitor dibenziodolium (DPI) partly inhibited the PA-induced ROS production and restored K_Ca2.3 expression. Inhibition of either p38-MAPK or NF-κB using specific inhibitors (SB203580, SB202190 or Bay11-7082, pyrrolidinedithiocarbamate) attenuated PA-induced downregulation of K_Ca2.3 and inhibition of p38-MAPK also attenuated PA-induced phosphorylation of NF-κB p65. Furthermore, DPI reversed the increment of phospho-p38-MAPK by PA. These results demonstrated that PA downregulated K_Ca2.3 expressions via Nox/ROS/p38-MAPK/NF-κB signaling leading to endothelial vasodilatory dysfunction.

Atorvastatin Attenuates Cold-Induced Hypertension by Preventing Gut Barrier Injury

Chronic exposure to cold causes arterial hypertension [cold-induce hypertension (CIH)]. Emerging data have indicated that gut barrier dysfunction is involved in the pathogenesis of hypertension. In this study, we explored the effect of gut barrier dysfunction on vascular inflammation induced by cold exposure and the therapeutic effect of atorvastatin in a CIH rat model. The CIH was established by cold exposure for 2 weeks. Two groups of Sprague Dawley rats were exposed to moderate cold (4 ± 1°C), whereas the control group was maintained at room temperature (23 ± 1°C) (10 rats/group). The 2 groups received atorvastatin or vehicle at the beginning of cold exposure, respectively, for 2 weeks. Cold exposure increased mean arterial pressure compared with room temperature group, indicating that animals developed arterial hypertension. Cold exposure induced vascular dysfunction due to decreasing phosphorylated endothelial nitric oxide synthase protein expression in aorta, and these were blunted by atorvastatin. Cold exposure increased the levels of gut-derived inflammatory cytokines, tumor necrosis factor-α, and interleukin-6 production in aorta and resulted in vascular inflammation, whereas atorvastatin prevented these effects. Cold exposure also increased gut permeability, inhibited tight junction protein expression in proximal colon, and resulted in gut barrier dysfunction. Interestingly, atorvastatin eliminated increasing gut permeability, decreasing tight junction protein expression, and gut pathology and reversed gut barrier dysfunction. Atorvastatin attenuated CIH and improved gut barrier function; the beneficial effects might be via inhibiting gut-derived inflammatory cytokines and reversing cold-induced vascular inflammation, suggesting that gut barrier dysfunction may be involved in the pathogenesis of CIH.

Untargeted metabolomic analysis of coronary artery disease patients with diastolic dysfunction show disturbed oxidative pathway

INTRODUCTION

Left ventricular diastolic dysfunction (LVDD) is common in patients with coronary artery disease (CAD) with prevalence estimates of 34% and constitutes a predictor of all-cause mortality. Although diastolic dysfunction is induced by myocardial ischemia and has been shown to alter the clinical course, the role of coronary artery disease in the diastolic dysfunction and its progression into heart failure has not been completely elucidated.

OBJECTIVE

The present study was conducted to identify possible metabolites in coronary artery disease patients that are differentially regulated in patients with diastolic dysfunction.

METHODS

The serum of CAD (n = 75) patients and young healthy volunteers (n = 43) were analysed by using gas chromatography mass spectrometry (GC-MS) technique. Pre-processing of data results in 1547 features; among them 1064 features were annotated using NIST library.

RESULTS AND CONCLUSION

Fifteen metabolites were found to be statistically different between cases and control. Variation in metabolites were identified and correlated with several clinically important echocardiography parameters i.e. LVDD grades, ejection fraction (EF) and E/e' values. The results suggested that metabolic products of fatty acid oxidation and glucose oxidation pathways such as oleic acid, stearic acid, palmitic acid, linoleic acid, galactose, pyruvic and lactic acids are predominantly up regulated in patients with coronary artery disease and severity of diastolic dysfunction appears to be linked to increase in fatty acid oxidation and inflammation. The metabolic fingerprints of these patients give us an insight into the pathophysiological mechanism of diastolic dysfunction in coronary artery disease patients although it did not identify validated novel markers.

Thymoquinone and geraniol alleviate cisplatin-induced neurotoxicity in rats through downregulating the p38 MAPK/STAT-1 pathway and oxidative stress

AIMS

Cisplatin (CP) is a widely used broad-spectrum antineoplastic agent used to treat a variety of human malignancies. Neurotoxicity is clinically evident in patients who have undergone a full course of chemotherapy. The aim of this study was to investigate the possible protective effects of thymoquinone (TQ) and geraniol (Ger) against CP-induced neurotoxicity in rats.

MAIN METHODS

Forty male Wistar albino rats were allocated into four groups as follows: normal control, CP-induced neurotoxicity, CP + TQ and CP + Ger.

KEY FINDINGS

Our results demonstrated that simultaneous treatment with either TQ or Ger and CP significantly abrogated oxidative stress and downregulated the apoptotic markers p38 mitogen-activated protein kinase (MAPK), STAT-1, p53, p21 and MMP9; FMO3, however, was insignificantly decreased. In addition to the biochemical results, we assessed the histopathological findings, which confirmed the protective effect of TQ and Ger against the brain damage induced by CP.

SIGNIFICANCE

The results of the present study indicate that simultaneous treatment with either TQ or Ger as natural antioxidants can provide protection against cisplatin-induced neurotoxicity in rats by attenuating oxidative stress and cell apoptosis.

Tocomin Restores Endothelium-Dependent Relaxation in the Diabetic Rat Aorta by Increasing NO Bioavailability and Improving the Expression of eNOS

We aimed to determine whether tocomin, an extract from palm oil that has a high tocotrienol content, was able to prevent diabetes-induced endothelial dysfunction. To induce type 1 diabetes streptozotocin (50 mg/kg) was injected into the tail vein of Wistar rats. Six weeks later the diabetic rats, and normal rats injected with citrate buffer, commenced treatment with tocomin (40 mg/kg/day sc) or its vehicle (peanut oil) for a further 4 weeks. Aortae isolated from diabetic rats had impaired acetylcholine (ACh)-induced endothelium-dependent relaxation compared to normal rat aortae but there was no change in endothelium-independent relaxation in response to sodium nitroprusside. By contrast, responses to ACh in aortae from diabetic rats treated with tocomin were not different to normal rats. In addition to impaired endothelium-dependent relaxation the diabetic aortae had increased expression of the NADPH oxidase Nox2 subunit, increased generation of superoxide and decreased expression of eNOS and all of these effects were prevented by tocomin treatment. Tocomin did not affect plasma glucose levels. The impaired response to ACh in vitro was maintained in the presence of TRAM-34 and apamin, selective inhibitors of calcium-activated potassium (K Ca ) channels, indicating diabetes impaired the contribution of NO to endothelium-dependent relaxation. By contrast, neither diabetes nor tocomin treatment influenced EDH-type relaxation as, in the presence of L-NNA, an inhibitor of eNOS, and ODQ, to inhibit soluble guanylate cyclase, responses to ACh were similar in all treatment groups. Thus tocomin treatment improves NO mediated endothelium dependent relaxation in aortae from diabetic rats associated with a decrease in vascular oxidant stress but without affecting hyperglycaemia.

Ticagrelor protects against AngII-induced endothelial dysfunction by alleviating endoplasmic reticulum stress

Ticagrelor has been reported to decrease cardiovascular mortality compared with clopidogrel. This benefit cannot be fully explained by the more efficient platelet inhibition. Many studies demonstrated that ticagrelor improved endothelial function, leaving the mechanism elusive though. The present study aims to investigate whether ticagrelor protects against endothelial dysfunction induced by angiotensinII (AngII) through alleviating endoplasmic reticulum (ER) stress. Male Sprague Dawley rats were infused with AngII or vehicle and administrated with ticagrelor or vehicle for 14 days. Reactive oxygen species (ROS) was detected. Aortas from normal mice were incubated with endoplasmic reticulum stress inducer tunicamycin with or without ticagrelor. Vasorecactivity was measured on wire myography. Rat aortic endothelial cells (RAECs) were pretreated with ticagrelor followed by AngII or tunicamycin. Endothelial nitric oxide synthase (eNOS) phosphorylation and ER stress markers were determined by western blotting. Impaired endothelial function, induction of ER stress, reduced eNOS phosphorylation and elevated ROS generation was restored by ticagrelor treatment in vivo. In addition, tunicamycin induced endothelial dysfunction was improved by ticagrelor. In vitro, the induction of ER stress and inhibited eNOS phosphorylation in REACs exposed to AngII as well as tunicamycin was reversed by co-culturing with ticagrelor. In conclusion, ticagrelor protects against AngII-induced endothelial dysfunction via alleviating ER stress.

Relaxin alleviates TGFβ1-induced cardiac fibrosis via inhibition of Stat3-dependent autophagy

Cardiac fibrosis is a pathological feature common to a variety of heart diseases such as myocardial infarction, arrhythmias, cardiomyopathies and heart failure. Emerging data has indicted that autophagy is involved in fibrotic synthesis. Relaxin as a pleiotropic hormone can attenuate cardiac fibrosis and hypertrophy, however the exact molecular mechanism remains largely unknown. In this work, we evaluated whether the antifibrotic effect of relaxin relies on regulating autophagy in primary cardiac fibroblasts (CFs). Our results showed that relaxin significantly attenuated TGFβ1-induced autophagy in parallel with the reduction of fibrosis. Moreover, relaxin inhibited the phosphorylation of Stat3/Smad3 signaling. Then we observed that knockdown of Stat3 synchronously suppressed the fibrogenesis and autophagic flux which was stimulated by TGFβ1 in CFs. More importantly, we simultaneously administrated relaxin and Stat3 knockdown into CFs, which did not cause further downregulation of autophagy process and collagen protein compared with only Stat3 knockdown or relaxin treatment. These data suggested that relaxin ameliorates TGFβ-induced fibrosis dependent on Stat3 signaling-mediated autophagy. This study uncovered a previously unrecognized antifibrotic role of relaxin in cardiac fibrosis, which is achieved through the inhibition of Stat3-dependent autophagy, implying a potential therapeutic target in fibrotic diseases.

Tocotrienol-Rich Tocomin Attenuates Oxidative Stress and Improves Endothelium-Dependent Relaxation in Aortae from Rats Fed a High-Fat Western Diet

We have previously reported that tocomin, a mixture high in tocotrienol content and also containing tocopherol, acutely preserves endothelial function in the presence of oxidative stress. In this study, we investigated whether tocomin treatment would preserve endothelial function in aortae isolated from rats fed a high-fat diet known to cause oxidative stress. Wistar hooded rats were fed a western diet (WD, 21% fat) or control rat chow (standard diet, 6% fat) for 12 weeks. Tocomin (40 mg/kg/day sc) or its vehicle (peanut oil) was administered for the last 4 weeks of the feeding regime. Aortae from WD rats showed an impairment of endothelium-dependent relaxation that was associated with an increased expression of the NADPH oxidase Nox2 subunit and an increase in the vascular generation of superoxide measured using L-012 chemiluminescence. The increase in vascular oxidative stress was accompanied by a decrease in basal NO release and impairment of the contribution of NO to ACh-induced relaxation. The impaired relaxation is likely contributed to by a decreased expression of eNOS, calmodulin, and phosphorylated Akt and an increase in caveolin. Tocotrienol rich tocomin, which prevented the diet-induced changes in vascular function, reduced vascular superoxide production and abolished the diet-induced changes in eNOS and other protein expression. Using selective inhibitors of nitric oxide synthase (NOS), soluble guanylate cyclase (sGC) and calcium-activated potassium (K_Ca) channels we demonstrated that tocomin increased NO-mediated relaxation, without affecting the contribution of endothelium-dependent hyperpolarization type relaxation to the endothelium-dependent relaxation. The beneficial actions of tocomin in this diet-induced model of obesity suggest that it may have potential to be used as a therapeutic agent to prevent vascular disease in obesity.