Gallic acid attenuates hypertension, cardiac remodeling, and fibrosis in mice with N G-nitro-L-arginine methyl ester-induced hypertension via regulation of histone deacetylase 1 or histone deacetylase 2

The hydroxamic acid derivative YPX-C-05 alleviates hypertension and vascular dysfunction through the PI3K/Akt/eNOS pathway

BACKGROUND

Hypertension is a prevalent cardiovascular disease characterized by elevated blood pressure and increased vascular resistance. HDAC inhibitors have emerged as potential therapeutic agents due to their ability to modulate gene expression and cellular processes. YPX-C-05, a novel hydroxamic acid-based HDAC inhibitor, shows promise in its vasodilatory effects and potential targets for hypertension treatment. In this study, we aimed to elucidate the mechanisms underlying YPX-C-05's vasodilatory effects and explore its therapeutic potential in hypertension.

METHODS

To determine the ex vivo vasodilatory effects of YPX-C-05, isolated aortic rings precontracted with phenylephrine were used. We assessed YPX-C-05's inhibitory effects on HDACs and its impact on histone H4 deacetylation levels in endothelial cells. Network pharmacology analysis was employed to predict putative targets of YPX-C-05 for hypertension treatment. To investigate the involvement of the PI3K/Akt/eNOS pathway, we employed enzyme-linked immunosorbent assay and to assess the levels of NO, ET-1, BH2, and BH4 in human umbilical vein endothelial cells. And we also analyzed the mRNA expression of eNOS and ET-1. Furthermore, Western blotting was conducted to quantify the phosphorylated and total Akt and eNOS levels in human umbilical vein endothelial cell lysates following treatment with YPX-C-05. In order to elucidate the vasodilatory mechanism of YPX-C-05, we employed pharmacological inhibitors for evaluation purposes. Furthermore, we evaluated the chronic antihypertensive effects of YPX-C-05 on N-omega-nitro-L-arginine-induced hypertensive mice in an in vivo model. Vascular remodeling was assessed through histological analysis.

RESULTS

Our findings demonstrated that YPX-C-05 exerts significant vasodilatory effects in isolated aortic rings precontracted with phenylephrine. Furthermore, YPX-C-05 exhibited inhibitory effects on HDACs and increased histone H4 acetylation in endothelial cells. Network pharmacology analysis predicted YPX-C-05 might activate endothelial eNOS via PI3K/Akt signaling pathway. Inhibition of the PI3K/Akt/eNOS pathway attenuated the vasodilatory effects of YPX-C-05, as evidenced by reduced levels of phosphorylated Akt and eNOS in human umbilical vein endothelial cell lysates. The chronic administration of YPX-C-05 in N-omega-nitro-L-arginine-induced hypertensive mice resulted in significant antihypertensive effects. Histological analysis demonstrated a reduction in vascular remodeling, further supporting the therapeutic potential of YPX-C-05 in hypertension.

CONCLUSION

This study demonstrates for the first time that the novel hydroxamic acid-based HDAC inhibitor YPX-C-05 produces significant antihypertensive and vasodilatory effects through the PI3K/Akt/eNOS pathway. Our findings support the developing prospect of YPX-C-05 as a novel antihypertensive drug.

Cardioprotective and hypotensive mechanistic insights of hydroethanolic extract of Cucumis melo L. kernels in isoprenaline-induced cardiotoxicity based on metabolomics and in silico electrophysiological models

Background: Cardiovascular diseases (CVD) continue to threaten health worldwide, and account for a significant portion of deaths and illnesses. In both developing and industrialized nations, they challenge their health systems. There are several traditional uses of Cucurbitaceae seeds in Pakistan, India, Iran, and China, including treating cardiovascular, neurological, and urogenital diseases. Methods: In the present work, integrated techniques of metabolomics profiling and computational cardiomyocyte stimulation were used to investigate possible mechanisms of C. melo in isoprenaline (ISO)-induced myocardial infarction. In vitro, vasoconstrictions, paired atria, and in vivo invasive blood pressure measurement models were performed to explore the mechanism of action of C. melo hydroethanolic seed extract (Cm-EtOH). Results: Results showed that Cm-EtOH demonstrates NO-based endothelium-derived relaxing factor (EDRF) vasorelaxant response, negative chronotropic and inotropic response in the atrium, and hypotensive effects in normotensive rats. Results also revealed that Cm-EtOH decreases cardiomyocyte hypertrophy and reverts the altered gene expressions, biochemical, and metabolites in ISO-induced myocardial infarction (MI) rats. The extract additionally reversed ISO-induced MI-induced oxidative stress, energy consumption, and amino acid metabolism. Moreover, C. melo seeds increased EDRF function, energy production, and antioxidant capacity to treat myocardial and vascular disorders. In computational cardiomyocyte simulation, gallic acid reduced action potential duration, upstroke velocity (dV/dtmax), and effective refractory period. Conclusion: This study highlights the therapeutic potential of C. melo seeds to treat cardiovascular diseases and provides mechanistic insight into its antihypertensive and cardioprotective activities.

Gallic Acid Inhibits Proliferation and Migration of Smooth Muscle Cells in a Pig In-Stent Restenosis Model

In-stent restenosis (ISR) develops primarily due to neointimal hyperplasia. Gallic acid (GA) has anti-inflammatory, antioxidant, and cardioprotective effects. This study sought to investigate the effects of GA on neointimal hyperplasia and proliferation and migration of vascular smooth muscle cells (VSMCs) in a pig ISR model. In vitro proliferation and migration experiments were confirmed, after VSMCs were treated with platelet-derived growth factor (PDGF-BB) and GA (100 µM) using a 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay and a scratch wound assay for 24 hours and 48 hours. A bare metal stent (BMS) was implanted in the pig coronary artery to induce ISR with overdilation (1.1-1.2:1), and GA (10 mg/kg/day) was administered for 4 weeks. At the 4-week follow-up, optical coherence tomography (OCT) and histopathological analyses were performed. GA decreased the proliferation of VSMCs by PDGF-BB for 24 hours (89.24±24.56% vs. 170.04±19.98%, p<0.001) and 48 hours (124.87±7.35% vs. 187.64±4.83%, p<0.001). GA inhibited the migration of VSMCs induced by PDGF-BB for 24 hours (26.73±2.38% vs. 65.38±9.73%, p<0.001) and 48 hours (32.96±3.04% vs. 77.04±10.07%, p<0.001). Using OCT, % neointimal hyperplasia was shown to have significantly decreased in the GA group compared with control vehicle group (28.25±10.07% vs. 37.60±10.84%, p<0.001). GA effectively reduced neointimal hyperplasia by inhibiting the proliferation and migration of VSMCs in a pig ISR model. GA could be a potential treatment strategy for reducing ISR after stent implantation.

Protective Roles and Therapeutic Effects of Gallic Acid in the Treatment of Cardiovascular Diseases: Current Trends and Future Directions

Cardiovascular diseases (CVDs) are serious life-threatening illnesses and significant problematic issues for public health having a heavy economic burden on all society worldwide. The high incidence of these diseases as well as high mortality rates make them the leading causes of death and disability. Therefore, finding novel and more effective therapeutic methods is urgently required. Gallic acid, an herbal medicine with numerous biological properties, has been utilized in the treatment of various diseases for thousands of years. It has been demonstrated that gallic acid possesses pharmacological potential in regulating several molecular and cellular processes such as apoptosis and autophagy. Moreover, gallic acid has been investigated in the treatment of CVDs both in vivo and in vitro. Herein, we aimed to review the available evidence on the therapeutic application of gallic acid for CVDs including myocardial ischemia-reperfusion injury and infarction, drug-induced cardiotoxicity, hypertension, cardiac fibrosis, and heart failure, with a focus on underlying mechanisms.

A validated bioanalytical method for the simultaneous estimation of telmisartan and gallic acid in rat plasma samples by high-performance thin-layer chromatography-mass spectrometry: Application to an oral pharmacokinetic study

A novel and cost-effective high-performance thin-layer chromatography (HPTLC) method, combined with densitometric quantification, was developed for the biomedical analysis of telmisartan (TEL) and gallic acid (GA). Recent research indicates that when used in combination, these compounds offer improved therapeutic efficacy for the treatment of cardiovascular diseases with reduced side effects. The study focused on the simultaneous quantification and pharmacokinetic analysis of drugs in rat plasma. The separation was conducted using HPTLC silica gel 60 F254 plates with dimensions of 20 × 10 cm and a thickness of 0.2 mm. The mobile phase used for separation consisted of a mixture of ethyl acetate, methanol, chloroform, and acetic acid in the ratio of 4:2:2:0.2 (v/v). GA and TEL were analyzed using ultraviolet detection at specific wavelengths, with GA at 280 nm and TEL at 296 nm. Peak purity was assessed through spectral correlation analysis using Vision CATS software. The method underwent validation following the guidelines of the US Food and Drug Administration (US FDA). Calibration plots demonstrated linearity in the concentration range of 200-1200 ng/spot, with high correlation coefficients (R2 ). The retention factors (Rf ) were 0.67 for TEL and 0.60 for GA. The identity of the separated compounds was further confirmed using MS, with GA having a mass-to-charge ratio (m/z) of 168.9 in negative mode and TEL with m/z 515.2 in positive mode. In the pharmacokinetic study, the maximum peak plasma concentration (Cmax ) for GA was 899.7 ng/mL, and for TEL, it was 1013 ng/mL. The time to reach maximum concentration (Tmax ) was 2 h for GA and 6 h for TEL. This simultaneous qualitative and quantitative determination of the drugs in an oral pharmacokinetic study involving Wistar rats can serve as a valuable tool for future investigations into pharmacokinetic interactions, quality control, and routine analysis of these drugs, both in their pure forms and in novel formulations.

Ling-Gui-Qi-Hua formula alleviates left ventricular myocardial fibrosis in rats with heart failure with preserved ejection fraction by blocking the transforming growth factor-β1 /Smads signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ling-Qui-Qi-Hua (LGQH) decoction, composed of Poria cocos (Schw.) Wolf, Cinnamomum cassia (L.) J. Presl, Paeonia veitchii Lynch, and Atractylodes macrocephala Koidz., is a compound formula derived from Ling-Gui-Zhu-Gan decoction recorded in the Treatise on Febrile and Miscellaneous. It has shown cardioprotective effects on patients or rats with heart failure with preserved ejection fraction (HFpEF). Nevertheless, the active ingredients of LGQH and its anti-fibrotic mechanism remain unknown.

AIM OF THE STUDY

To determine the active ingredients in LGQH decoction and verify that LGQH decoction may inhibit left ventricular (LV) myocardial fibrosis in HFpEF rats by blocking the transforming growth factor-β1 (TGF-β1)/Smads signaling pathway from the perspective of animal experiments.

MATERIALS AND METHODS

First, liquid chromatography-mass spectrometry (LC-MS) technology was used to identify active components in the LGQH decoction. Secondly, a rat model of the metabolic syndrome-associated HFpEF phenotype was established and subsequently received LGQH intervention. The mRNA and protein expression of targets in the TGF-β1/Smads pathway were detected by quantitative real-time polymerase chain reaction and western blot analysis. Finally, molecular docking was conducted to examine the interactions between the active ingredients in the LGQH decoction and key proteins of the TGF-β1/Smads pathways.

RESULTS

According to LC-MS analysis, the LGQH decoction contained 13 active ingredients. In animal experiments, LGQH attenuated LV hypertrophy, enlargement, and diastolic function in HEpEF rats. Mechanically, LGQH not only down-regulated TGF-β1, Smad2, Smad3, Smad4, α-SMA, Coll I, and Coll III mRNA expressions and TGF-β1, Smad2, Smad3, P-Smad2/Smad3, Smad4, α-SMA, and Coll I protein expressions, but also up-regulated Smad7 mRNA and protein expressions, which ultimately led to myocardial fibrosis. Furthermore, molecular docking confirmed that 13 active ingredients in the LGQH decoction have excellent binding activities to the critical targets of the TGF-β1/Smads pathway.

CONCLUSION

LGQH is a modified herbal formulation with multiple active ingredients. It might alleviate LV remodeling and diastolic dysfunction and inhibit LV myocardial fibrosis by blocking TGF-β1/Smads pathways in HFpEF rats.

Impact of polyphenols on heart failure and cardiac hypertrophy: clinical effects and molecular mechanisms

Polyphenols are abundant in regular diets and possess antioxidant, anti-inflammatory, anti-cancer, neuroprotective, and cardioprotective effects. Regarding the inadequacy of the current treatments in preventing cardiac remodeling following cardiovascular diseases, attention has been focused on improving cardiac function with potential alternatives such as polyphenols. The following online databases were searched for relevant orginial published from 2000 to 2023: EMBASE, MEDLINE, and Web of Science databases. The search strategy aimed to assess the effects of polyphenols on heart failure and keywords were "heart failure" and "polyphenols" and "cardiac hypertrophy" and "molecular mechanisms". Our results indicated polyphenols are repeatedly indicated to regulate various heart failure-related vital molecules and signaling pathways, such as inactivating fibrotic and hypertrophic factors, preventing mitochondrial dysfunction and free radical production, the underlying causes of apoptosis, and also improving lipid profile and cellular metabolism. In the current study, we aimed to review the most recent literature and investigations on the underlying mechanism of actions of different polyphenols subclasses in cardiac hypertrophy and heart failure to provide deep insight into novel mechanistic treatments and direct future studies in this context. Moreover, due to polyphenols' low bioavailability from conventional oral and intravenous administration routes, in this study, we have also investigated the currently accessible nano-drug delivery methods to optimize the treatment outcomes by providing sufficient drug delivery, targeted therapy, and less off-target effects, as desired by precision medicine standards.

Edible mushrooms as potential functional foods in amelioration of hypertension

Edible mushrooms are popular functional foods attributed to their rich nutritional bioactive constituent profile influencing cardiovascular function. Edible mushrooms are omnipresent in various prescribed Dietary Approaches to Stop Hypertension, Mediterranean diet, and fortified meal plans as they are rich in amino acids, dietary fiber, proteins, sterols, vitamins, and minerals. However, without an understanding of the influence of mushroom bioactive constituents, mechanism of action on heart and allergenicity, it is difficult to fully comprehend the role of mushrooms as dietary interventions in alleviating hypertension and other cardiovascular malfunctions. To accomplish this endeavor, we chose to review edible mushrooms and their bioactive constituents in ameliorating hypertension. Hypertension and cardiovascular diseases are interrelated and if the former is managed by dietary changes, it is postulated that overall heart health could also be improved. With a concise note on different edible varieties of mushrooms, a particular focus is presented on the antihypertensive potential of mushroom bioactive constituents, mode of action, absorption kinetics and bioavailability. Ergosterol, lovastatin, cordycepin, tocopherols, chitosan, ergothioneine, γ-aminobutyric acid, quercetin, and eritadenine are described as essential bioactives with hypotensive effects. Finally, safety concerns on allergens and limitations of consuming edible mushrooms with special reference to chemical toxins and their postulated metabolites are highlighted. It is opined that the present review will redirect toxicologists to further investigate mushroom bioactives and allergens, thereby influencing dietary interventions for heart health.

Phytochemicals as potential target on thioredoxin-interacting protein (TXNIP) for the treatment of cardiovascular diseases

Cardiovascular diseases (CVDs) are currently the major cause of death and morbidity on a global scale. Thioredoxin-interacting protein (TXNIP) is a marker related to metabolism, oxidation, and inflammation induced in CVDs. The overexpression of TXNIP is closely related to the occurrence and development of CVDs. Hence, TXNIP inhibition is critical for reducing the overactivation of its downstream signaling pathway and, as a result, myocardial cell damage. Due to the chemical variety of dietary phytochemicals, they have garnered increased interest for CVDs prevention and therapy. Phytochemicals are a source of medicinal compounds for a variety of conditions, which aids in the development of effective and safe TXNIP-targeting medications. The objective of this article is to find and virtual screen novel safe, effective, and economically viable TXNIP inhibitors from flavonoids, phenols, and alkaloids derived from foods and plants. The results of the docking study revealed that silibinin, rutin, luteolin, baicalin, procyanidin B2, hesperetin, icariin, and tilianin in flavonoids, polydatin, resveratrol, and salidroside in phenols, and neferine in alkaloids had the highest Vina scores, indicating that these compounds are the active chemicals on TXNIP. In particular, silibinin can be utilized as a lead chemical in the process of structural alteration. These dietary phytochemicals may aid in the discovery of lead compounds for the development of innovative TXNIP agents for the treatment of cardiovascular disease.

Therapeutic and Nutraceutical Effects of Polyphenolics from Natural Sources

The prevalence of cardiovascular disease, oxidative stress-related complications, and chronic age-related illnesses is gradually increasing worldwide. Several causes include the ineffectiveness of medicinal treatment therapies, their toxicity, their inability to provide radical solutions in some diseases, and the necessity of multiple drug therapy in certain chronic diseases. It is therefore necessary for alternative treatment methods to be sought. In this review, polyphenols were identified and classified according to their chemical structure, and the sources of these polyphenol molecules are indicated. The cardioprotective, ROS scavenging, anti-aging, anticancer properties of polyphenolic compounds have been demonstrated by the results of many studies, and these natural antioxidant molecules are potential alternative therapeutic agents.

Comparison of the Antihypertensive Activity of Phenolic Acids

Phenolic acids, found in cereals, legumes, vegetables, and fruits, have various biological functions. We aimed to compare the antihypertensive potential of different phenolic acids by evaluating their ACE inhibitory activity and cytoprotective capacity in EA.hy 926 endothelial cells. In addition, we explored the mechanism underlying the antihypertensive activity of sinapic acid. Of all the phenolic acids studied, sinapic acid, caffeic acid, coumaric acid, and ferulic acid significantly inhibited ACE activity. Moreover, gallic acid, sinapic acid, and ferulic acid significantly enhanced intracellular NO production. Based on the results of GSH depletion, ROS production, and MDA level analyses, sinapic acid was selected to study the mechanism underlying the antihypertensive effect. Sinapic acid decreases endothelial dysfunction by enhancing the expression of antioxidant-related proteins. Sinapic acid increased phosphorylation of eNOS and Akt in a dose-dependent manner. These findings indicate the potential of sinapic acid as a treatment for hypertension.

Yang-xin-xue keli exerts therapeutic effects via regulating mitochondrial homeostasis and function in doxorubicin-induced rat heart failure

Background: Heart failure, especially chronic heart failure, is generally induced by the accumulation of reactive oxygen species (ROS), as well as the subsequent loss of mitochondrial permeability transition pore (mPTP) openings and pathological mitochondrial dysfunction. Herein, we explored the therapeutic effects of the Chinese medicine Yangxin Keli (YXXKL) on chronic heart failure and its underlying working mechanism.

Methods: To mimic oxidative stress-induced chronic heart failure, a rat heart failure model was induced by the administration of DOX. Transthoracic echocardiography was performed to confirm the successful establishment of the heart failure model by observing significantly decreased cardiac function in the rats. Mitochondrial membrane potential, function, and ATP synthesis activity were measured after YXXKL was employed.

Results The administration of YXXKL not only significantly improved cardiac function but also reversed the myocardium loss and fibrosis induced via DOX. Moreover, the administration of YXXKL also increased ATP synthesis and mitochondrial DNA mass in left ventricular tissues, which indicated that mitochondria may be a key target of YXXKL. Thus, we employed rat cardiomyocyte H9c2 and primary rat cardiac myocytes (RCMs) to induce oxidative stress-induced myocardial injury via DOX treatment. YXXKL-medicated serum promoted cell proliferation, which was inhibited by the addition of IC30 DOX, and the serum also inhibited cell apoptosis, which was promoted by the addition of IC50 DOX. YXKL-medicated serum was able to scavenge ROS and maintain the mitochondrial membrane potential as well as promote mitochondrial function, including the promotion of ATP synthesis, mitochondrial DNA mass, and transcriptional activity. Furthermore, we also observed that YXXKL-medicated serum inhibited DOX-induced autophagy/mitophagy by scavenging ROS.

Conclusion: Taken together, we conclude that YXXKLI may exert therapeutic effects on oxidative stress-related heart failure via the regulation of mitochondria.

Focusing on Mechanoregulation Axis in Fibrosis: Sensing, Transduction and Effecting

Fibrosis, a pathologic process featured by the excessive deposition of connective tissue components, can affect virtually every organ and has no satisfactory therapy yet. Fibrotic diseases are often associated with organ dysfunction which leads to high morbidity and mortality. Biomechanical stmuli and the corresponding cellular response havebeen identified in fibrogenesis, as the fibrotic remodeling could be seen as the incapacity to reestablish mechanical homeostasis: along with extracellular matrix accumulating, the physical property became more “stiff” and could in turn induce fibrosis. In this review, we provide a comprehensive overview of mechanoregulation in fibrosis, from initialing cellular mechanosensing to intracellular mechanotransduction and processing, and ends up in mechanoeffecting. Our contents are not limited to the cellular mechanism, but further expand to the disorders involved and current clinical trials, providing an insight into the disease and hopefully inspiring new approaches for the treatment of tissue fibrosis.

Ameliorative role of Ulva extract against heavy metal mixture-induced cardiovascular through oxidative/antioxidant pathways and inflammatory biomarkers

The current study investigates the therapeutic and curative effect of Ulva lactuca polyphenolic extract (ULPE) in general and particularly polyphenolics compounds against heavy metal mixture (HME). The toxicity behind heavy metal is due to oxidative stress resulted from heavy metals pollution or administration through contaminated food (vegetables, water, and fish). Heavy metal toxicity plays a major role in different cardiovascular diseases. The objective of this study is aimed to examine the protective effect of ULPE against heavy metal mixture induced cardiovascular diseases through oxidative/antioxidant and inflammatory pathways. Sixty male rats (Sprague-Dawley) were assigned to six groups. Group I served as the control, group II served as the induced group receiving subcutaneously for 7 days 0.25 mg/100 gm body weight/day heavy metal mixtures (Equal concentration of Ni, Cd, Co and Hg chloride, and Pb acetate), group III received (i.p.) ULPE of dose 30 mg for 15 days, group IV served as the protected group pretreated with ULPE for 15 days as a protection dose, and then treated with the heavy metal-mixture, group V served as protected standard group pretreated with vitamin C (VitC ) (50 mg/Kg) and then treated with the heavy metal-mixture, and group VI served as standard group treated with VitC (50 mg/Kg). The main pathological changes within the heart revealed heart inflammation after heavy-metal mixtures administrations. On contrast to the protected group treated with ULPE (group IV), the protection group (group II) showed a significant increase in the antioxidant as well as anti-inflammatory biomarker. The cardiovascular biomarkers (Troponin T, CRP, and BNP) showed similar attitude elevations in induction group and decreased greatly in protection and VitC group. The antioxidant and the anti-inflammatory activities of ULPE are a consequence of their higher polyphenolic contents as well as marine secondary metabolites which are confirmed using qualitative and quantitative analysis. From the current result, we concluded that ULPE possesses a cardiovascular protective agent as a result of highly contents of different bioactive secondary metabolites which have antioxidant as well as free-radical scavenging and anti-inflammatory activates. Showed the mechanism of ULPE as cardioprotective against heavy metal mixture.

The regulation of protein acetylation influences the redox homeostasis to protect the heart

The cellular damage caused by redox imbalance is involved in the pathogenesis of many cardiovascular diseases. Besides, redox imbalance is related to the alteration of protein acetylation processes, causing not only chromatin remodeling but also disturbances in so many processes where protein acetylation is involved, such as metabolism and signal transduction. The modulation of acetylases and deacetylases enzymes aids in maintaining the redox homeostasis, avoiding the deleterious cellular effects associated with the dysregulation of protein acetylation. Of note, regulation of protein acetylation has shown protective effects to ameliorate cardiovascular diseases. For instance, HDAC inhibition has been related to inducing cardiac protective effects and it is an interesting approach to the management of cardiovascular diseases. On the other hand, the upregulation of SIRT protein activity has also been implicated in the relief of cardiovascular diseases. This review focuses on the major protein acetylation modulators described, involving pharmacological and bioactive compounds targeting deacetylase and acetylase enzymes contributing to heart protection through redox homeostasis.

Selective HDAC8 Inhibition Attenuates Isoproterenol-Induced Cardiac Hypertrophy and Fibrosis via p38 MAPK Pathway

Histone deacetylase (HDAC) expression and enzymatic activity are dysregulated in cardiovascular diseases. Among Class I HDACs, HDAC2 has been reported to play a key role in cardiac hypertrophy; however, the exact function of HDAC8 remains unknown. Here we investigated the role of HDAC8 in cardiac hypertrophy and fibrosis using the isoproterenol-induced cardiac hypertrophy model system.Isoproterenol-infused mice were injected with the HDAC8 selective inhibitor PCI34051 (30 mg kg⁻¹ body weight). Enlarged hearts were assessed by HW/BW ratio, cross-sectional area, and echocardiography. RT-PCR, western blotting, histological analysis, and cell size measurements were performed. To elucidate the role of HDAC8 in cardiac hypertrophy, HDAC8 knockdown and HDAC8 overexpression were also used. Isoproterenol induced HDAC8 mRNA and protein expression in mice and H9c2 cells, while PCI34051 treatment decreased cardiac hypertrophy in isoproterenol-treated mice and H9c2 cells. PCI34051 treatment also reduced the expression of cardiac hypertrophic markers (Nppa, Nppb, and Myh7), transcription factors (Sp1, Gata4, and Gata6), and fibrosis markers (collagen type I, fibronectin, and Ctgf) in isoproterenol-treated mice. HDAC8 overexpression stimulated cardiac hypertrophy in cells, whereas HDAC8 knockdown reversed those effects. HDAC8 selective inhibitor and HDAC8 knockdown reduced the isoproterenol-induced activation of p38 MAPK, whereas HDAC8 overexpression promoted p38 MAPK phosphorylation. Furthermore, p38 MAPK inhibitor SB203580 significantly decreased the levels of p38 MAPK phosphorylation, as well as ANP and BNP protein expression, induced by HDAC8 overexpression.Here we show that inhibition of HDAC8 activity or expression suppresses cardiac hypertrophy and fibrosis. These findings suggest that HDAC8 could be a promising target to treat cardiac hypertrophy and fibrosis by regulating p38 MAPK.

Identification of gallic acid as a active ingredient of Syzygium aromaticum against tacrolimus-induced damage in renal epithelial LLC-PK1 cells and rat kidney

Tacrolimus (FK506), a calcineurin inhibitor, is an effective immunosuppressive agent mainly used to lower the risk of organ rejection after allogeneic organ transplant. However, FK506-associated adverse effects, such as nephrotoxicity, may limit its therapeutic use. In this study, we confirmed that epigallocatechin-3-gallate (EGCG), sanguiin H-6, and gallic acid increased cell survival following FK506-induced cytotoxicity in renal epithelial LLC-PK1. Among these compounds, gallic acid exerted the strongest protective effect, further confirmed in the FK506-induced nephrotoxicity rat model. Additionally, we identified supporting evidence for the nephroprotective function of gallic acid using molecular docking and bioavailability investigations.

MicroRNA-212-5p and its target PAFAH1B2 suppress vascular proliferation and contraction via the downregulation of RhoA

Vascular remodeling and contraction contribute to the development of hypertension. We investigated the role of miR-212-5p and its downstream target in vascular smooth muscle cell (VSMC) proliferation, migration, and contraction. MicroRNA microarray and PCR analyses showed that miR-212-5p expression was increased with angiotensin II treatment in vivo and in vitro. Moreover, miR-212-5p mimic treatment attenuated and miR-212-5p inhibitor treatment increased VSMC proliferation and migration. Additionally, miR-212-5p mimic treatment suppressed VSMC contraction and related gene expression [Ras homolog gene family member A (RhoA) and Rho-associated protein kinase 2], while miR-212-5p inhibitor treatment exerted opposite effects. Bioinformatics analysis revealed that platelet-activating factor acetylhydrolase 1B2 (PAFAH1B2) is a target of miR-212-5p. miR-212-5p mimic treatment significantly reduced and miR-212-5p inhibitor treatment increased PAFAH1B2 expression. Furthermore, PAFAH1B2 expression was decreased in angiotensin II-treated aortic tissues and VSMCs. PAFAH1B2 was ubiquitously expressed in most adult rat tissues. In the vasculature, PAFAH1B2 was only distributed in the cytoplasm. PAFAH1B2 overexpression decreased A10 cell proliferation, while PAFAH1B2 knockdown increased A10 cell proliferation and cyclin D1 mRNA levels. PAFAH1B2 knockdown stimulated VSMC contraction and RhoA expression. These results suggest that miR-212-5p and PAFAH1B2 are novel negative regulators of VSMC proliferation, migration, and contraction in hypertension.

Ethnopharmacological basis for folkloric claims of Anagallis arvensis Linn. (Scarlet Pimpernel) as prokinetic, spasmolytic and hypotensive in province of Punjab, Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE

The conventional naturopaths of Punjab Province (Pakistan) have trivial usage of Anagallis arvensis Linn.(Primulaceae) for cure of diarrhea, constipation, asthma as well as hypertension.

AIM

Present research was focused to discover comprehensive mechanism of spasmogenic, spasmolytic, bronchorelaxant and hypotensive folkloric usage of Anagallis arvensis Linn..

METHODOLOGY

The crude extract of Anagallis arvensis Linn. (Aa.Cr) & its (aqueous & organic) portions tested in-vitro on isolated jejunum, ileum, trachea, aorta, paired atria preparations as well as in-vivo in mice & normotensive anaesthetized rats. The responses have been noted by transducers (isotonic & isometric) coupled to Power Lab.

RESULT

Anagallis arvensis Linn. (Aa.Cr; crude aqueous-alcoholic extract) produced contractile action at low concentrations but relaxant action was observed by increasing concentrations on spontaneous contractions of isolated jejunum of rabbit. But, pre-treatment of tissue with atropine prior extract caused suppression of contractile effect indicating presence of cholinergic muscarinic response of Aa.Cr. It also triggered relaxation of high Potassium -stimulated contractions of jejunum with subsequent non-parallel right move in Ca++ CRCs. Moreover, Aa.Cr relaxed carbachol - & high Potassium - stimulated contractions in trachea of rabbit but observed relaxant effect was powerful against CCh (1 μM)- stimulated contractions with rightside parallel move of CCh-curves succeeded by non-parallel move, like Dicyclomine, having dual activities. The Aa.Cr also showed relaxant result on Phenylephrine and High Potassium -prompted contractions in endothelium intact aorta. The fractionation revealed segregations of contractile & relaxant effects in relevant aqueous & organic portions. The Intravenous administration of Aa.Cr to ketamine-diazepam anaesthetized normo-tensive albino rats resulted in decreased MABP, SBP & DBP. The Aa.Cr applied negative (-) inotropic & chronotropic action on paired atria. The Aa.Cr also exhibited anti-diarrheal action in mice against castor oil prompted diarrhea and also mitigated distance covered by charcoal meal in gastrointestinal tract in a manner comparable with loperamide.

CONCLUSION

These results revealed presence of CCB and selective muscarinic agonist activity in Aa.Cr, hence validating folkloric practice of Anagallis arvensis Linn. in diarrhea, constipation, asthma & hypertension.

Flavonoids as natural phenolic compounds and their role in therapeutics: an overview

Background

Natural plants and plant-derived formulations have been used by mankind from the ancient period of time. For the past few years, many investigations elaborated the therapeutic potential of various secondary chemicals present in the plants. Literature revealed that the various secondary metabolites, viz. phenolics and flavonoids, are responsible for a variety of therapeutic action in humans.

Main body

In the present review, an attempt has been made to compile the exploration of natural phenolic compounds with major emphasis on flavonoids and their therapeutic potential too. Interestingly, long-term intake of many dietary foods (rich in phenolics) proved to be protective against the development and management of diabetes, cancer, osteoporosis, cardiovascular diseases and neurodegenerative diseases, etc.

Conclusion

This review presents an overview of flavonoid compounds to use them as a potential therapeutic alternative in various diseases and disorders. In addition, the present understanding of phenolics and flavonoids will serve as the basis for the next scientific studies.

Methyl Gallate Attenuates Doxorubicin-Induced Cardiotoxicity in Rats by Suppressing Oxidative Stress

Doxorubicin-induced cardiotoxicity is the leading cause of morbidity and mortality among cancer survivors. The present study was aimed to investigate the cardioprotective potential of methyl gallate; an active polyphenolic nutraceutical, against doxorubicin-induced cardiotoxicity in Wistar rats. Twenty-four female Wistar rats (150-200 g) were divided into four groups (n = 6) which consist of normal control (group I), doxorubicin control (group II), test-A (group III), and test-B (group IV). Group III and group IV animals were prophylactically treated with methyl gallate 150 mg/kg/day and 300 mg/kg/day orally, respectively, for seven days. Doxorubicin (25 mg/kg; single dose) was administered through an intraperitoneal route to group II, III, and IV animals on the seventh day to induce acute cardiotoxicity. On the 8^th day, besides ECG analysis, serum CK, CK-MB, LDH, AST, MDA, and GSH were assayed. Following gross examination of isolated hearts, histopathological evaluation was performed by light microscopy. A significant (p < 0.05) cardiac injury, as well as oxidative stress, was observed in doxorubicin control rats in comparison to normal control rats. Methyl gallate at both the doses significantly (p < 0.05) reduced doxorubicin-induced ECG changes, dyslipidaemia, and elevation of CK, CK-MB, LDH, AST, MDA and increased GSH level. Methyl gallate reversed the doxorubicin-induced histopathological changes in the heart. The present study revealed that methyl gallate exerts cardioprotection against doxorubicin-induced cardiotoxicity in female Wistar rats by suppressing oxidative stress. Our study opens the perspective to clinical studies for consideration of methyl gallate as a potential chemoprotectant nutraceutical in the combination chemotherapy with doxorubicin to limit its cardiotoxicity.

Allelopathic Potential and Active Substances from Wedelia Chinensis (Osbeck)

Wedelia chinensis (Asteraceae) is a wetland herb native to India, China, and Japan. It is a valuable medicinal plant recorded to have pharmaceutical properties. However, the phytotoxic potential of Wedelia chinensis has not yet been examined. Thus, we carried out this study to establish the allelopathic effects of Wedelia chinensis and to identify its phytotoxic substances. Extracts of Wedelia chinensis exhibited high inhibitory activity against the root and shoot growth of cress, alfalfa, rapeseed, lettuce, foxtail fescue, Italian ryegrass, timothy, and barnyard grass. The inhibition was varied with species and was dependent on concentrations. The extracts were separated through several purification steps, and the two effective substances were isolated and characterized as vanillic acid and gallic acid using spectral analysis. Vanillic acid and gallic acid significantly arrested the growth of cress and Italian ryegrass seedlings. The concentrations of vanillic acid and gallic acid needed for 50% inhibition (I₅₀ values) of the seedling growth of the cress and Italian ryegrass were 0.04–15.4 and 0.45–6.6 mM, respectively. The findings suggest that vanillic acid and gallic acid may be required for the growth inhibitory activities of Wedelia chinensis.

Cuphea calophylla var. mesostemon (Koehne) S.A. Graham: A Whole-Ethnopharmacological Investigation

Several species of Cuphea are used medicinally and are reported to have cardioprotective, diuretic, and antihypertensive properties. In Brazil, Cuphea species are collectively called "sete-sangrias" due to their similar appearances and are also used interchangeably for the same therapeutic purposes. So the aim of the study was to characterize morphoanatomy of leaves and stems, evaluate the safety, and investigate the diuretic, hypotensive, vasodilatory, and antioxidant properties of ethanol-soluble fraction of Cuphea calophylla var. mesostemon (Koehne) S.A. Graham. Initially, the morphoanatomical characterization of the leaves and stems of C. calophylla var. mesostemon was performed. For the pharmacological evaluation, the ethanol-soluble fraction from Cuphea calophylla (ESCC) was obtained and chemically characterized by high-performance liquid chromatography coupled with a diode array detector and tandem mass spectrometry techniques. Then, acute toxicity, diuretic, hypotensive, antioxidant, and vasodilatory effects were evaluated in Wistar rats. The main chemical compounds identified from ESCC were gallic acid derivatives, ellagitannins, and flavonoids. ESCC showed no acute toxic effect. ESCC showed no acute toxic effect and the estimated median lethal dose (LD₅₀) was above 2000 mg/kg. ESCC treatment (30, 100, and 300 mg/kg) did not present any significant acute diuretic or hypotensive effects. However, an important reduction in the elimination of electrolytes was observed after the acute administration, and a significant increase in renal sodium elimination was observed after 7 days of treatment. In the cardiac tissue, the groups treated with ESCC presented significant increase in superoxide dismutase activity.

Studies to Elucidate the Mechanism of Cardio Protective and Hypotensive Activities of Anogeissus acuminata (Roxb. ex DC.) in Rodents

Anogeissus acuminata (Roxb. ex DC.) is a folkloric medicinal plant in Asia; including Pakistan; used as a traditional remedy for cardiovascular disorders. This study was planned to establish a pharmacological basis for the trivial uses of Anogeissus acuminata in certain medical conditions related to cardiovascular systems and to explore the underlying mechanisms. Mechanistic studies suggested that crude extract of Anogeissus acuminata (Aa.Cr) produced in vitro cardio-relaxant and vasorelaxant effects in isolated paired atria and aorta coupled with in vivo decrease in blood pressure by invasive method; using pressure and force transducers connected to Power Lab Data Acquisition System. Moreover; Aa.Cr showed positive effects in left ventricular hypertrophy in Sprague Dawley rats observed hemodynamically by a decrease in cardiac cell size and fibrosis; along with absence of inflammatory cells; coupled with reduced levels of angiotensin converting enzyme (ACE) and renin concentration along with increased concentrations of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP). In Acute Myocardial Infarction (AMI) model; creatine kinase (CK), creatine kinase-MB (CK-MB) and lactic acid dehydrogenase (LDH levels) were found to be decreased; along with decreased necrosis; edema and recruitment of inflammatory cells histologically. In vivo and ex vivo studies of Anogeissus acuminata provided evidence of vasorelaxant; hypotensive and cardioprotective properties facilitated through blockage of voltage-gated Ca⁺⁺ ion channel; validating its use in cardiovascular diseases.

Gallic Acid Attenuates Angiotensin II-Induced Hypertension and Vascular Dysfunction by Inhibiting the Degradation of Endothelial Nitric Oxide Synthase

Hypertension is a major cause of heart attack and stroke. Our recent study revealed that gallic acid (GA) exerts protective effects on pressure overload-induced cardiac hypertrophy and dysfunction. However, the role of GA in angiotensin II (Ang II)-induced hypertension and vascular remodeling remains unknown. C57BL/6J mice were subjected to saline and Ang II infusion. Systolic blood pressure was measured using a tail-cuff system. Vascular remodeling and oxidative stress were examined by histopathological staining. Vasodilatory function was evaluated in the aortic ring. Our findings revealed that GA administration significantly ameliorated Ang II-induced hypertension, vascular inflammation, and fibrosis. GA also abolished vascular endothelial dysfunction and oxidative stress in Ang II-infused aortas. Mechanistically, GA treatment attenuated Ang II-induced upregulation of the immunoproteasome catalytic subunits β2i and β5i leading to reduction of the trypsin-like and chymotrypsin-like activity of the proteasome, which suppressed degradation of endothelial nitric oxide synthase (eNOS) and reduction of nitric oxide (NO) levels. Furthermore, blocking eNOS activity by using a specific inhibitor (_L-N^G-nitroarginine methyl ester) markedly abolished the GA-mediated beneficial effect. This study identifies GA as a novel immunoproteasome inhibitor that may be a potential therapeutic agent for hypertension and vascular dysfunction.

Ex vivo and in vivo studies of Viola tricolor Linn. as potential cardio protective and hypotensive agent: Inhibition of voltage-gated Ca++ ion channels

Viola tricolor Linn. is used as cardio-protective and anti-hypertensive agent in traditional medicine. Current study objective was to evaluate cardio-protective and hypotensive effects of Viola tricolor L. in vitro and in vivo studies. Viola tricolor L. crude extract (Vt.Cr) and its fractions (Aqueous and organic) were tested at rabbit atria and aorta coupled to Power Lab Data Acquisition System for cardio depressant and vasorelaxant effects in vitro whereas in vivo Blood Pressure was checked by invasive method in normotensive ketamine-diazepam anesthetized rats. Isoproterenol was employed for acute myocardial infarction (AMI) and left ventricular hypertrophy (LVH) development and cardioprotective effects of Vt.Cr were evaluated hemodynamically and histopathologically. Vt.Cr and its fractions decreased heart rate and contractile force in paired atria and relaxed Phenylephrine (1 µM) and K⁺ (80 mM) stimulated contractions in aorta possibly mediated through Voltage dependent L-type calcium channels blockage supported by in vivo hypotensive action. In LVH, Vt.Cr lowered Angiotensin Converting Enzymes and renin, increased cyclic Guanosine Monophosphate and nitric oxide levels, decreased cardiomyocytes size and fibrosis attributed to Gallic acid as detected by High Performance Liquid Chromatography. Partial positive results were seen hemodynamically and histologically in AMI Viola tricolor L. showed vasorelaxant, cardio-relaxant, hypotensive, and cardio protective effect validating traditional practice in cardiovascular disorders.

Antihypertensive phytocomplexes of proven efficacy and well-established use: Mode of action and individual characterization of the active constituents

Hypertension has become the leading risk factor for worldwide cardiovascular diseases. Conventional pharmacological treatment, after both dietary and lifestyle changes, is generally proposed. In this review, we present the antihypertensive properties of phytocomplexes from thirteen plants, long ago widely employed in ethnomedicines and, in recent years, increasingly evaluated for their activity in vitro and in vivo, also in humans, in comparison with synthetic drugs acting on the same systems. Here, we focus on the demonstrated or proposed mechanisms of action of such phytocomplexes and of their constituents proven to exert cardiovascular effects. Almost seventy phytochemicals are described and scientifically sound pertinent literature, published up to now, is summarized. The review emphasizes the therapeutic potential of these natural substances in the treatment of the 'high normal blood pressure' or 'stage 1 hypertension', so-named according to the most recent European and U.S. guidelines, and as a supplementation in more advanced stages of hypertension, however needing further validation by clinical trial intensification.

Pu-Erh Tea Relaxes the Thoracic Aorta of Rats by Reducing Intracellular Calcium

Previous studies suggested that pu-erh tea aqueous extract could lower blood pressure and ameliorate hypertension symptoms. However, the antihypertension mechanisms of pu-erh tea remain unclear. In this work, the direct effects of pu-erh tea on vessels and cells were investigated by detecting isometric tension and intracellular calcium ([Ca²⁺]_i), respectively. Additionally, to identify the main active components, the aqueous extract of pu-erh was separated by organic solvents to obtain various fractions, and the effects of these fractions on arteries were assessed. The results showed that pu-erh aqueous extract vasodilated rat thoracic aortas preconstricted by phenylephrine or KCl. These vasodilation effects were not significantly affected by the removal of the endothelium or by preincubation with potassium channel blockers (tetraethylammonium, glibenclamide, aminopyridine, or barium chloride). Moreover, pu-erh aqueous extract could reduce the vessel contractibility induced by CaCl₂ and phenylephrine under KCl-depolarizing or Ca²⁺-free buffer conditions, respectively. Furthermore, pu-erh aqueous extract attenuated the KCl-induced increase in [Ca²⁺]_i in cultured rat aortic smooth muscle A7r5 cells. In addition, the chloroform precipitate of pu-erh aqueous extract produced the most potent vasodilation. Theabrownins (the characteristic components of pu-erh tea) accounted for 41.91 ± 1.09 % of the chloroform precipitate and vasodilated arteries in an endothelium-independent manner. In addition, the vasodilation effect of caffeine was verified. In conclusion, theabrownins and caffeine should be the two main active components in pu-erh tea. Pu-erh aqueous extract vasodilated arteries in an endothelium-independent manner, which might partly be attributed to the decrease in extracellular Ca²⁺ influx. Moreover, our study provided data on the potential mechanism of the hypotensive actions of pu-erh tea, which might improve our understanding of the effect of pu-erh tea on the prevention and treatment of hypertension.

A Role of Gallic Acid in Oxidative Damage Diseases: A Comprehensive Review

Gallic acid is a trihydroxybenzoic acid of plant metabolites widely spread throughout the plant kingdom. It has characteristics of the strong antioxidant and free radical scavenging activities, and can protect biological cells, tissues, and organs from damages caused by oxidative stress. This review aims to summarize the protective roles of gallic acid and the underlying pharmacological mechanisms in the pathophysiological process of the oxidative damage diseases, such as cancer, cardiovascular, degenerative, and metabolic diseases. The studies reviewed herein showed that the main therapeutic effects of gallic acid were attributed to its antioxidant properties. It modulated various signaling pathways through a wide range of inflammatory cytokines, and enzymic and nonenzymic antioxidants. However, the available data were limited to few studies assessing the treatment effects of gallic acid in human subjects to confirm its therapeutic outcomes. Therefore, the clinical trials were urgently needed to investigate the safety and efficacy of gallic acid treatment on human beings. The scientific data summarized in this review highlighted the therapeutic potentials of gallic acid for oxidative damage diseases. It could be developed as versatile adjuvant or therapeutically lead compound in future.

HDAC inhibitors as antifibrotic drugs in cardiac and pulmonary fibrosis

Fibrosis usually results from dysregulated wound repair and is characterized by excessive scar tissue. It is a complex process with unclear mechanisms. Accumulating evidence indicates that epigenetic alterations, including histone acetylation, play a pivotal role in this process. Histone acetylation is governed by histone acetyltransferases (HATs) and histone deacetylases (HDACs). HDACs are enzymes that remove the acetyl groups from both histone and nonhistone proteins. Aberrant HDAC activities are observed in fibrotic diseases, including cardiac and pulmonary fibrosis. HDAC inhibitors (HDACIs) are molecules that block HDAC functions. HDACIs have been studied extensively in a variety of tumors. Currently, there are four HDACIs approved by the US Food and Drug Administration for cancer treatment yet none for fibrotic diseases. Emerging evidence from in vitro and in vivo preclinical studies has presented beneficial effects of HDACIs in preventing or reversing fibrogenesis. In this review, we summarize the latest findings of the roles of HDACs in the pathogenesis of cardiac and pulmonary fibrosis and highlight the potential applications of HDACIs in these two fibrotic diseases.

Targeting the Gut Microbiota to Investigate the Mechanism of Lactulose in Negating the Effects of a High-Salt Diet on Hypertension

SCOPE

High-salt diets (HSDs) are widely considered to cause health problems such as gut microecological imbalances, constipation, and hypertension. This study explores how lactulose as a safe molecule can stimulate bodily responses to alleviate salt-sensitive hypertension by regulating the gut microbiotas of HSD-fed mice.

METHODS AND RESULTS

After 4 weeks, the blood pressures of mice fed a high-salt plus lactulose diet (HSLD) are significantly lower than those of the HSD-fed mice. The HSD increases the abundances of Alistipes and Ruminococcaceae_UCG_009 and reduced the abundance of Lactobacillus in the gut, while lactulose supplementation increases the abundances of Bifidobacterium, Alloprevotella, and Subdoligranulum. Fecal metabolic profiling shows significant increases in metabolites involved in ATP-binding cassette transporter pathways, and tryptophan metabolism is significantly reduced in the HSLD group compared with the HSD group. Lactulose maintains the intestinal microenvironmental health in the HSD-fed mice by improving glycolipid metabolism, decreasing the small intestinal interleukin-17a (IL-17a) and interleukin-22 (IL-22) mRNA levels and serum IL-17a and IL-22 levels, relieving constipation, increasing fecal sodium, and reducing intestinal permeability.

CONCLUSION

Lactulose negates salt-sensitive hypertension. Regulating the gut microbiota is a potential treatment for salt-sensitive hypertension.

Pharmacological effects of gallic acid in health and diseases: A mechanistic review

OBJECTIVES

Gallic acid is a natural phenolic compound found in several fruits and medicinal plants. It is reported to have several health-promoting effects. This review aims to summarize the pharmacological and biological activities of gallic acid in vitro and animal models to depict the pharmacological status of this compound for future studies.

MATERIALS AND METHODS

All relevant papers in the English language were collected up to June 2018. The keywords of gallic acid, antioxidant, anticancer, antimicrobial, gastrointestinal-, cardiovascular-, metabolic-, neuropsychological-, and miscellaneous- diseases were searched in Google Scholar, PubMed, and Scopus.

RESULTS

Several beneficial effects are reported for gallic acid, including antioxidant, anti-inflammatory, and antineoplastic properties. This compound has been reported to have therapeutic activities in gastrointestinal, neuropsychological, metabolic, and cardiovascular disorders.

CONCLUSION

Current evidence confirms the pharmacological and therapeutic interventions of gallic acid in multiple health complications; however, available data are limited to just cellular and animal studies. Future investigations are essential to further define the safety and therapeutic efficacy of gallic acid in humans.

Reactive Oxygen Species Drive Epigenetic Changes in Radiation-Induced Fibrosis

Radiation-induced fibrosis (RIF) develops months to years after initial radiation exposure. RIF occurs when normal fibroblasts differentiate into myofibroblasts and lay down aberrant amounts of extracellular matrix proteins. One of the main drivers for developing RIF is reactive oxygen species (ROS) generated immediately after radiation exposure. Generation of ROS is known to induce epigenetic changes and cause differentiation of fibroblasts to myofibroblasts. Several antioxidant compounds have been shown to prevent radiation-induced epigenetic changes and the development of RIF. Therefore, reviewing the ROS-linked epigenetic changes in irradiated fibroblast cells is essential to understand the development and prevention of RIF.

Gallic Acid Suppresses Cardiac Hypertrophic Remodeling and Heart Failure

SCOPE

Gallic acid (GA) is a dietary phenolic acid found in tea, red wine, and some plants. It exhibits anti-oxidative and anti-inflammatory activities. Recent studies have revealed that GA has beneficial effects against several cardiovascular diseases; however, whether GA attenuates pressure-overload-induced cardiac hypertrophy and the underlying mechanism remains unclear.

METHODS AND RESULTS

Primary cardiomyocyte hypertrophy is stimulated with angiotensin II (Ang II). Cardiac hypertrophic remodeling is induced in mice by transverse aortic constriction (TAC). Myocardial function is evaluated by echocardiographic and hemodynamic analyses, while cardiac tissues are analyzed by histological staining. It is observed that GA significantly decreases Ang II-induced increases in cardiomyocyte size in vitro. Administration of GA in mice markedly improves TAC-induced cardiac dysfunction and attenuates pathological changes, including cardiac myocyte hypertrophy, fibrosis, inflammation, and oxidative stress. Mechanistically, GA inhibits ULK1 and activates autophagy, which induces the degradation of EGFR, gp130, and calcineurin A, thereby inhibiting the downstream signaling cascades (AKT, ERK1/2, JAK2/STAT3, and NFATc1).

CONCLUSIONS

The results demonstrate for the first time that GA prevents myocardial hypertrophy and dysfunction via an autophagy-dependent mechanism. Thus, GA represents a promising therapeutic candidate for treating cardiac hypertrophy and heart failure.

Upregulation of C/EBPβ and TSC2 by an HDAC inhibitor CG200745 protects heart from DOCA-induced hypertrophy

Histone deacetylases (HDACs) are a vast family divided into four major classes: class I (1, 2, 3, and 8), class II (4, 5, 6, 7, 9 and 10), class III (sirtuin family) and class IV (HDAC11). HDAC inhibition attenuates cardiac hypertrophy through suppression of the mechanistic target of rapamycin complex1 (mTORC1) signaling. HDAC inhibitors upregulate the expression of tuberous sclerosis complex 2 (TSC2), an mTORC1 inhibitor. However, the molecular mechanism underlying HDAC inhibitor-mediated upregulation of TSC2 is unclear. We hypothesized that an HDAC inhibitor, CG200745 (CG), ameliorates cardiac hypertrophy through the inhibition of mTORC1 signaling by upregulating of the CCAAT/enhancer-binding protein-β (C/EBP-β)/TSC2 pathway. To establish a cardiac hypertrophy model, deoxycorticosterone acetate (DOCA, 40 mg/kg/wk) was subcutaneously injected for 4 weeks into Sprague-Dawley rats. All rats were unilaterally nephrectomized and had free access to drinking water containing 1% NaCl with or without CG of different concentrations. The expression level of TSC2 and C/EBP-β was measured by quantitative real-time PCR (qRT-PCR) and western blot analysis. Acetylation of C/EBP-β was analyzed by immunoprecipitation. The recruitment of C/EBP-β and polymerase II (Pol II) on TSC2 promoter region was analyzed by chromatin immunoprecipitation (ChIP). CG treatment increased the expression of TSC2. In addition, CG treated rats showed an increased in the expression and acetylation of C/EBP-β, owing to the increase in the recruitment of C/EBP-β and Pol II at Tsc2 gene promoter. Thus, CG ameliorates cardiac hypertrophy through the inhibition of mTORC1 signaling via upregulation of the C/EBP-β/TSC2 pathway in DOCA-induced hypertensive rats.

Gentisic acid attenuates pressure overload-induced cardiac hypertrophy and fibrosis in mice through inhibition of the ERK1/2 pathway

We previously reported that gentisic acid (2,5‐dihydroxybenzoic acid) is the third most abundant phenolic component of Dendropanax morbifera branch extracts. Here, we investigated its effects on cardiac hypertrophy and fibrosis in a mouse model of pressure overload and compared them to those of the beta blocker bisoprolol and calcium channel blocker diltiazem. Cardiac hypertrophy was induced in mice by transverse aortic constriction (TAC). Beginning 2 weeks after this procedure, the mice were given daily intraperitoneal injections of gentisic acid (100 mg/kg/d), bisoprolol (5 mg/kg/d) or diltiazem (10 mg/kg/d) for 3 weeks. Cardiac hypertrophy was evaluated by the heart weight‐to‐body weight ratio, the cardiomyocyte cross‐sectional area after haematoxylin and eosin staining, and echocardiography. Markers of cardiac hypertrophy and fibrosis were tested by reverse transcription‐quantitative real‐time polymerase chain reaction, western blotting and Masson's trichrome staining. The suppressive effects of gentisic acid treatment on TAC‐induced cardiac hypertrophy and fibrosis were comparable to those of bisoprolol administration. Cardiac hypertrophy was reversed and left ventricular septum and posterior wall thickness were restored by gentisic acid, bisoprolol and diltiazem treatment. Cardiac hypertrophic marker gene expression and atrial and brain natriuretic peptide levels were decreased by gentisic acid and bisoprolol, as were cardiac (interstitial and perivascular) fibrosis and fibrosis‐related gene expression. Cardiac hypertrophy‐associated upregulation of the transcription factors GATA4 and Sp1 and activation of extracellular signal‐regulated kinase 1/2 were also negated by these drugs. These results suggest that gentisic acid could serve as a therapeutic agent for cardiac hypertrophy and fibrosis.

Gallic acid improves cardiac dysfunction and fibrosis in pressure overload-induced heart failure

Gallic acid is a trihydroxybenzoic acid found in tea leaves and some plants. Here, we report the effect of gallic acid on cardiac dysfunction and fibrosis in a mouse model of pressure overload-induced heart failure and in primary rat cardiac fibroblasts, and compare the effects of gallic acid with those of drugs used in clinics. Gallic acid reduces cardiac hypertrophy, dysfunction, and fibrosis induced by transverse aortic constriction (TAC) stimuli in vivo and transforming growth factor β1 (TGF-β1) in vitro. It decreases left ventricular end-diastolic and end-systolic diameter, and recovers the reduced fractional shortening in TAC. In addition, it suppresses the expression of atrial natriuretic peptide, brain natriuretic peptide, skeletal α-actin, and β-myosin heavy chain. Administration of gallic acid decreases perivascular fibrosis, as determined by Trichrome II Blue staining, and reduces the expression of collagen type I and connective tissue growth factor. However, administration of losartan, carvedilol, and furosemide does not reduce cardiac dysfunction and fibrosis in TAC. Moreover, treatment with gallic acid inhibits fibrosis-related genes and deposition of collagen type I in TGF-β1-treated cardiac fibroblasts. These results suggest that gallic acid is a therapeutic agent for cardiac dysfunction and fibrosis in chronic heart failure.

Gallic acid, a phenolic compound isolated from Mimosa bimucronata (DC.) Kuntze leaves, induces diuresis and saluresis in rats

Although present in the leaves of Mimosa bimucronata (DC.) and many other medicinal plants commonly used to augment urinary volume excretion, the effects of gallic acid as a diuretic agent remain to be studied. Wistar rats were orally treated with vehicle, hydrochlorothiazide, or gallic acid. The effects of gallic acid in the presence of hydrochlorothiazide, furosemide, amiloride, L-NAME, atropine, and indomethacin were also investigated. Diuretic index, pH, conductivity, and electrolyte excretion were evaluated at the end of the experiment (after 8 or 24 h). Gallic acid induced diuretic and saluretic (Na⁺ and Cl^-) effects, without interfering with K⁺ excretion, when orally given to female and male rats at a dose of 3 mg/kg. These effects were associated with increased creatinine and conductivity values while pH was unaffected by any of the treatments. Plasma Na⁺, K⁺, and Cl^- levels were not affected by any of the acute treatments. The combination with hydrochlorothiazide or furosemide was unable to intensify the effects of gallic acid when compared with the response obtained with each drug alone. On the other hand, the treatment with amiloride plus gallic acid amplified both diuresis and saluresis, besides to a marked potassium-sparing effect. Its diuretic action was significantly prevented in the presence of indomethacin, a cyclooxygenase inhibitor, but not with the pretreatments with L-NAME or atropine. Although several biological activities have already been described for gallic acid, this is the first study demonstrating its potential as a diuretic agent.

Gallic acid attenuates calcium calmodulin-dependent kinase II-induced apoptosis in spontaneously hypertensive rats

Hypertension causes cardiac hypertrophy and leads to heart failure. Apoptotic cells are common in hypertensive hearts. Ca²⁺/calmodulin‐dependent protein kinase II (CaMKII) is associated with apoptosis. We recently demonstrated that gallic acid reduces nitric oxide synthase inhibition‐induced hypertension. Gallic acid is a trihydroxybenzoic acid and has been shown to have beneficial effects, such as anti‐cancer, anti‐calcification and anti‐oxidant activity. The purpose of this study was to determine whether gallic acid regulates cardiac hypertrophy and apoptosis in essential hypertension. Gallic acid significantly lowered systolic and diastolic blood pressure in spontaneously hypertensive rats (SHRs). Wheat germ agglutinin (WGA) and H&E staining revealed that gallic acid reduced cardiac enlargement in SHRs. Gallic acid treatment decreased cardiac hypertrophy marker genes, including atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), in SHRs. The four isoforms, α, β, δ and γ, of CaMKII were increased in SHRs and were significantly reduced by gallic acid administration. Gallic acid reduced cleaved caspase‐3 protein as well as bax, p53 and p300 mRNA levels in SHRs. CaMKII δ overexpression induced bax and p53 expression, which was attenuated by gallic acid treatment in H9c2 cells. Gallic acid treatment reduced DNA fragmentation and the TUNEL positive cells induced by angiotensin II. Taken together, gallic acid could be a novel therapeutic for the treatment of hypertension through suppression of CaMKII δ‐induced apoptosis.

Gallic acid attenuates pulmonary fibrosis in a mouse model of transverse aortic contraction-induced heart failure

Gallic acid, a trihydroxybenzoic acid found in tea and other plants, attenuates cardiac hypertrophy, fibrosis, and hypertension in animal models. However, the role of gallic acid in heart failure remains unknown. In this study, we show that gallic acid administration prevents heart failure-induced pulmonary fibrosis. Heart failure induced in mice, 8weeks after transverse aortic constriction (TAC) surgery, was confirmed by echocardiography. Treatment for 2weeks with gallic acid but not furosemide prevented cardiac dysfunction in mice. Gallic acid significantly inhibited TAC-induced pathological changes in the lungs, such as increased lung mass, pulmonary fibrosis, and damaged alveolar morphology. It also decreased the expression of fibrosis-related genes, including collagen types I and III, fibronectin, connective tissue growth factor (CTGF), and phosphorylated Smad3. Further, it inhibited the expression of epithelial-mesenchymal transition (EMT)-related genes, such as N-cadherin, vimentin, E-cadherin, SNAI1, and TWIST1. We suggest that gallic acid has therapeutic potential for the treatment of heart failure-induced pulmonary fibrosis.

Antidepressant-like effect of gallic acid in mice: Dual involvement of serotonergic and catecholaminergic systems

AIMS

This study was planned to examine the antidepressant potency of gallic acid (30 and 60mg/kg), a phenolic acid widely distributed in nature, together with its possible underlying monoaminergic mechanisms.

MAIN METHODS

Antidepressant-like activity was assessed using the tail suspension (TST) and the modified forced swimming tests (MFST). Locomotor activity was evaluated in an activity cage.

KEY FINDINGS

Administration of gallic acid at 60mg/kg reduced the immobility duration of mice in both the TST and MFST without any changes in the locomotor activity. The anti-immobility effect observed in the TST was abolished with pre-treatment of p-chlorophenylalanine methyl ester (an inhibitor of serotonin synthesis; 100mg/kg i.p. administered for 4-consecutive days), ketanserin (a 5-HT2A/2C antagonist; 1mg/kg i.p.), ondansetron (a 5-HT3 antagonist; 0.3mg/kg i.p.), α-methyl-para-tyrosine methyl ester (an inhibitor of catecholamine synthesis; 100mg/kg i.p.), phentolamine (non-selective alpha-adrenoceptor antagonist; 5mg/kg i.p.), SCH 23390 (a dopamine D1 antagonist; 0.05mg/kg s.c.), and sulpiride (a dopamine D2/D3 antagonist; 50mg/kg i.p.). However, NAN 190 (a 5-HT1A antagonist; 0.5mg/kg i.p.) and propranolol (a non-selective β-adrenoceptor antagonist; 5mg/kg i.p.) pre-treatments were ineffective at reversing the antidepressant-like effects of gallic acid.

SIGNIFICANCE

The results of the present study indicate that gallic acid seems to have a dual mechanism of action by increasing not only serotonin but also catecholamine levels in synaptic clefts of the central nervous system. Further alpha adrenergic, 5-HT2A/2C and 5-HT3 serotonergic, and D1, D2, and D3 dopaminergic receptors also seem to be involved in this antidepressant-like activity.