Effects of aluminum oxide (Al2O3) nanoparticles on ECG, myocardial inflammatory cytokines, redox state, and connexin 43 and lipid profile in rats: possible cardioprotective effect of gallic acid

The Potential Health Benefits of Gallic Acid: Therapeutic and Food Applications

Gallic acid (GA), a phenolic acid found in fruits and vegetables, has been consumed by humans for centuries. Its extensive health benefits, such as antimicrobial, antioxidant, anticancer, anti-inflammatory, and antiviral properties, have been well-documented. GA's potent antioxidant capabilities enable it to neutralize free radicals, reduce oxidative stress, and protect cells from damage. Additionally, GA exerts anti-inflammatory effects by inhibiting inflammatory cytokines and enzymes, making it a potential therapeutic agent for inflammatory diseases. It also demonstrates anticancer properties by inhibiting cancer cell growth and promoting apoptosis. Furthermore, GA offers cardiovascular benefits, such as lowering blood pressure, decreasing cholesterol, and enhancing endothelial function, which may aid in the prevention and management of cardiovascular diseases. This review covers the chemical structure, sources, identification and quantification methods, and biological and therapeutic properties of GA, along with its applications in food. As research progresses, the future for GA appears promising, with potential uses in functional foods, pharmaceuticals, and nutraceuticals aimed at improving overall health and preventing disease. However, ongoing research and innovation are necessary to fully understand its functional benefits, address current challenges, and establish GA as a mainstay in therapeutic and nutritional interventions.

Aluminum oxide, cobalt aluminum oxide, and aluminum-doped zinc oxide nanoparticles as an effective antimicrobial agent against pathogens

Since the clock of antimicrobial resistance was set, modern medicine has shed light on a new cornerstone in technology to overcome the worldwide dread of the post-antimicrobial era. Research organizations are exploring the use of nanotechnology to modify metallic crystals from macro to nanoscale size, demonstrating significant interest in the field of antimicrobials. Herein, the antimicrobial activities of aluminum oxide (Al2O3), cobalt aluminum oxide (CoAl2O4), and aluminum doped zinc oxide (Zn0.9Al0.1O) nanoparticles were examined against some nosocomial pathogens. The study confirmed the formation and characterization of Al2O3, CoAl2O4, and Zn0.9Al0.1O nanoparticles using various techniques, revealing the generation of pure nanoscale nanoparticles. With inhibition zones ranging from 9 to 14 mm and minimum inhibitory concentrations varying from 4 mg/mL to 16 mg/mL, the produced nanoparticles showed strong antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Meanwhile, the bactericidal concentrations ranged from 8 mg/mL to 40 mg/mL. In culture, Zn0.9Al0.1O NPs demonstrated a unique ability to inhibit the development of nosocomial infections with high bactericidal activity (8 mg/mL). Transmission electron microscope images revealed changes in cell shape, bacterial cell wall morphology, cytoplasmic membrane, and protoplasm due to the introduction of tested nanoparticles. These results pave the way for the use of these easily bacterial wall-piercing nanoparticles in combination with potent antibiotics to overcome the majority of bacterial strains' resistance.

Top Five Stories of the Cellular Landscape and Therapies of Atherosclerosis: Current Knowledge and Future Perspectives

Atherosclerosis (AS) is characterized by impairment and apoptosis of endothelial cells, continuous systemic and focal inflammation and dysfunction of vascular smooth muscle cells, which is documented as the traditional cellular paradigm. However, the mechanisms appear much more complicated than we thought since a bulk of studies on efferocytosis, transdifferentiation and novel cell death forms such as ferroptosis, pyroptosis, and extracellular trap were reported. Discovery of novel pathological cellular landscapes provides a large number of therapeutic targets. On the other side, the unsatisfactory therapeutic effects of current treatment with lipid-lowering drugs as the cornerstone also restricts the efforts to reduce global AS burden. Stem cell- or nanoparticle-based strategies spurred a lot of attention due to the attractive therapeutic effects and minimized adverse effects. Given the complexity of pathological changes of AS, attempts to develop an almighty medicine based on single mechanisms could be theoretically challenging. In this review, the top stories in the cellular landscapes during the initiation and progression of AS and the therapies were summarized in an integrated perspective to facilitate efforts to develop a multi-targets strategy and fill the gap between mechanism research and clinical translation. The future challenges and improvements were also discussed.

A review of the epidemiological and laboratory evidence of the role of aluminum exposure in pathogenesis of cardiovascular diseases

The objective of the present study was to review the epidemiological and laboratory evidence on the role of aluminum (Al) exposure in the pathogenesis of cardiovascular diseases. Epidemiological data demonstrated an increased incidence of cardiovascular diseases (CVD), including hypertension and atherosclerosis in occupationally exposed subjects and hemodialysis patients. In addition, Al body burden was found to be elevated in patients with coronary heart disease, hypertension, and dyslipidemia. Laboratory studies demonstrated that Al exposure induced significant ultrastructural damage in the heart, resulting in electrocardiogram alterations in association with cardiomyocyte necrosis and apoptosis, inflammation, oxidative stress, inflammation, and mitochondrial dysfunction. In agreement with the epidemiological findings, laboratory data demonstrated dyslipidemia upon Al exposure, resulting from impaired hepatic lipid catabolism, as well as promotion of low-density lipoprotein oxidation. Al was also shown to inhibit paraoxonase 1 activity and to induce endothelial dysfunction and adhesion molecule expression, further promoting atherogenesis. The role of Al in hypertension was shown to be mediated by up-regulation of NADPH-oxidase, inhibition of nitric oxide bioavailability, and stimulation of renin-angiotensin-aldosterone system. It has been also demonstrated that Al exposure targets cerebral vasculature, which may be considered a link between Al exposure and cerebrovascular diseases. Findings from other tissues lend support that ferroptosis, pyroptosis, endoplasmic reticulum stress, and modulation of gut microbiome and metabolome are involved in the development of CVD upon Al exposure. A better understanding of the role of the cardiovascular system as a target for Al toxicity will be useful for risk assessment and the development of treatment and prevention strategies.

Sub-acute Inhalation Exposure to Aluminum Oxide Nanoparticles and its Effects on Wistar Rats as Opposed to the Micro-sized Chemical Analog

INTRODUCTION

Aluminum oxide nanoparticles (Al2O3 NPs) are widely used in various productions. Simultaneously, many research works report the toxic effects of this nanomaterial. Given that, there is a growing risk of negative effects produced by Al2O3 NPs on public health.

AIMS

This study aims to investigate the toxic effects of Al2O3 NPs as opposed to the micro-sized chemical analogue under sub-acute inhalation exposure.

MATERIALS AND METHODS

We identified the physical properties of Al2O3 NPs as opposed to the micro- sized chemical analogue, including size, specific surface area, and total pore volume. Inhalation exposure to Al2O3 NPs was simulated on Wistar rats in a chamber for whole-body. The animals were exposed for 4 hours each day for 28 days. NPs and MPs concentrations in the chamber were kept at ~ 1/4000 from LC50. Rats' behavior was examined prior to the exposure period and after it; after the last daily exposure, we examined biochemical and hematological blood indicators, NPs and MPs bioaccumulation, and pathomorphological changes in organ tissues.

RESULTS

The tested Al2O3 sample is a nanomaterial according to its analyzed physical properties. Rats' behavior changed more apparently under exposure to NPs compared to MPs. Aluminum levels, which were 1.62-55.20 times higher than the control, were identified in the lungs, liver, brain, and blood under exposure to NPs. These levels were also 1.55-7.65 times higher than the control under exposure to MPs. Biochemical indicators of rats' blood also changed under exposure to NPs against the control. We identified more active ALT, AST, ALP, and LDH, elevated levels of GABA, MDA, and conjugated bilirubin, and a lower level of Glu. As opposed to exposure to MPs, ALT, AST, and ALP were more active; GABA and MDA levels were higher; Glu level was lower. Under exposure to NPs, the number of platelets grew, whereas no similar effect occurred under exposure to MPs. We established pathomorphological changes in tissues of the lungs, brain, heart, and liver under exposure to Al2O3 NPs; similar changes occurred only in the lungs under exposure to MPs. Exposure to NPs induced changes in tissue structures in a wider range of various organs, and these changes were more apparent than under exposure to MPs.

CONCLUSION

Greater toxicity of Al2O3 NPs as opposed to MPs is evidenced by a wider range of organs where their bioaccumulation occurs, more apparent pathomorphological and pathological functional changes. Established peculiarities of toxic effects produced by the analyzed nanomaterial should be considered when developing hygienic recommendations aimed at preventing and mitigating adverse impacts of Al2O3 NPs on human health under inhalation exposure.

The aqueous extract of Artemisia Absinthium L. stimulates HO-1/MT-1/Cyp450 signaling pathway via oxidative stress regulation induced by aluminium oxide nanoparticles (α and γ) animal model

BACKGROUND

This research aimed to evaluate the protective effects of Artemisia Absinthium L. (Abs) against liver damage induced by aluminium oxide nanoparticles (Al2O3 NPs) in rats, including both structural and functional changes associated with hepatotoxicity.

METHODS

Thirty-six rats were randomly divided into six groups (n = 6). The first group received no treatment. The second group was orally administered Abs at a dose of 200 mg/kg/b.w. The third and fifth groups were injected intraperitoneally with γ-Al2O3 NPs and α-Al2O3 NPs, respectively, at a dose of 30 mg/kg/b.w. The fourth and sixth groups were pre-treated with oral Abs at a dose of 200 mg/kg/b.w. along with intraperitoneal injection of γ-Al2O3 NPs and α-Al2O3 NPs, respectively, at a dose of 30 mg/kg/b.w.

RESULTS

Treatment with γ-Al2O3 NPs resulted in a significant decrease (P < 0.05) in total body weight gain, relative liver weight to body weight, and liver weight in rats. However, co-administration of γ-Al2O3 NPs with Abs significantly increased body weight gain (P < 0.05). Rats treated with Al2O3 NPs (γ and α) exhibited elevated levels of malondialdehyde (MDA), inducible nitric oxide synthase (iNOS), alanine transaminase (ALT), and aspartate aminotransferase (AST). Conversely, treatment significantly reduced glutathione peroxidase (GPx), catalase (CAT), total superoxide dismutase (T-SOD), and total antioxidant capacity (TAC) levels compared to the control group. Furthermore, the expression of heme oxygenase-1 (HO-1) and metallothionein-1 (MT-1) mRNAs, cytochrome P450 (CYP P450) protein, and histopathological changes were significantly up-regulated in rats injected with Al2O3 NPs. Pre-treatment with Abs significantly reduced MDA, AST, HO-1, and CYP P450 levels in the liver, while increasing GPx and T-SOD levels compared to rats treated with Al2O3 NPs.

CONCLUSION

The results indicate that Abs has potential protective effects against oxidative stress, up-regulation of oxidative-related genes and proteins, and histopathological alterations induced by Al2O3 NPs. Notably, γ-Al2O3 NPs exhibited greater hepatotoxicity than α-Al2O3 NPs.

Effects of acute exposure to Al2O3-NPs (α and γ) and white noise and their combination on cochlea structure and function in Wistar rats

Hearing loss induced by noise and combinations of factors is a common occupational disease among workers. This study aimed to investigate the impact of acute exposure to white noise and Al2O3 NPs, alone and in combination, on changes in the hearing and structural functions of the cochlea in rats. Thirty-six rats were randomly assigned to one of six groups: Control, acute exposure to white noise, exposure to γ-Al2O3 NPs, exposure to noise plus γ-Al2O3 NPs, exposure to α-Al2O3 NPs, and exposure to the combination of noise plus α-Al2O3 NPs. TTS and PTS were examined using DPOAE, while oxidative index (MDA, GSH-Px), gene expression (NOX3, TGF-ß, CYP1A1), protein expression (ß-Tubulin, Myosin VII), and histopathological changes were examined in the cochlea. The morphology of Al2O3 NPs was examined by TEM. The results of the DPOAE test showed a significant increase in TTS in all groups and an increase in PTS in the groups exposed to noise, γ-Al2O3 NPs, and a combination of noise plus Al2O3 NPs (P < 0.05). In the group exposed to white noise plus Al2O3 NPs, the MDA levels increased, the level of GSH-Px decreased, and the expression percentage of ß-Tubulin and Myosin VII decreased, while the expression of NOX3, TGF-ß, and CYP1A1 (except for the α-Al2O3 NPs group) significantly increased (P < 0.05). Histopathological changes of the cochlea indicated damage to hair and ganglion cells, which was more severe in the combined exposure group. The combined and independent exposure to white noise and Al2O3 NPs damaged hair and ganglion cells for high-frequency perception, affecting the function and structure of the cochlea and leading to TTS and PTS.

Ameliorative effects of quercetin against hepatic toxicity of oral sub-chronic co-exposure to aluminum oxide nanoparticles and lead-acetate in male rats

The present study was designed to evaluate the probable ameliorative role of quercetin (QCN) against oxidative hepatotoxicity induced by aluminum oxide nanoparticles (Al2O3NPs) with a diameter < 30 nm and lead acetate (Pb) co-exposure in adult male Sprague–Dawley rats. Rats were weighed and allocated to seven groups (n = 10 each) and were treated orally via orogastric gavage for 60 successive days: rats of the 1st group were kept as control given distilled water (1 ml/kg), rats of the 2nd group received 2 ml/kg BW/day corn oil; rats of the 3rd group were administered 20 mg/kg BW QCN/day; rats of the 4th group received 100 mg/kg BW Al2O3NPs; rats of the 5th group received 50 mg/kg BW Pb; rats of the 6th group co-received Al2O3NPs and Pb at the same previous doses; and rats of the 7th group were co-administered Al2O3NPs, Pb, and QCN at the same previous doses. At the end of the experiment, serum levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total, direct, indirect bilirubin, triglycerides, total cholesterol, HDL, VLDL, and LDL were estimated. The hepatic oxidative stress biomarkers as superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPx), were also evaluated. Finally, the histopathological and histomorphometric evaluations and the residues of Al and Pb in hepatic tissues were assessed. Al2O3NPs and/or Pb exposure significantly elevated lipid peroxidation levels and considerably altered the hepatic biochemical parameters; nevertheless, QCN significantly reduced hepatic enzymes compared to toxicant exposed groups. Additionally, QCN significantly improved Al2O3NPs-afforded liver tissue damage, as established in microscopic findings on the liver in the group treated with Al2O3NPs + Pb. Conclusively, QCN could be a candidate natural agent to safeguard the liver versus the co-harmful impacts of Al2O3NPs and Pb toxicity.

Critical Review on Toxicological Mechanisms Triggered by Inhalation of Alumina Nanoparticles on to the Lungs

Alumina nanoparticles (Al₂O₃ NPs) can be released in occupational environments in different contexts such as industry, defense, and aerospace. Workers can be exposed by inhalation to these NPs, for instance, through welding fumes or aerosolized propellant combustion residues. Several clinical and epidemiological studies have reported that inhalation of Al₂O₃ NPs could trigger aluminosis, inflammation in the lung parenchyma, respiratory symptoms such as cough or shortness of breath, and probably long-term pulmonary fibrosis. The present review is a critical update of the current knowledge on underlying toxicological, molecular, and cellular mechanisms induced by exposure to Al₂O₃ NPs in the lungs. A major part of animal studies also points out inflammatory cells and secreted biomarkers in broncho-alveolar lavage fluid (BALF) and blood serum, while in vitro studies on lung cells indicate contradictory results regarding the toxicity of these NPs.

Flavonoid and Phenolic Acid Profiles of Dehulled and Whole Vigna subterranea (L.) Verdc Seeds Commonly Consumed in South Africa

Bambara groundnut (BGN) is an underexploited crop with a rich nutrient content and is used in traditional medicine, but limited information is available on the quantitative characterization of its flavonoids and phenolic acids. We investigated the phenolic profile of whole seeds and cotyledons of five BGN varieties consumed in South Africa using UPLC-qTOF-MS and GC-MS. Twenty-six phenolic compounds were detected/quantified in whole seeds and twenty-four in cotyledon, with six unidentified compounds. Flavonoids include flavan-3-ol (catechin, catechin hexoside-A, catechin hexoside-B), flavonol (quercetin, quercetin-3-O-glucoside, rutin, myricetin, kaempherol), hydroxybenzoic acid (4-Hydroxybenzoic, 2,6 Dimethoxybenzoic, protocatechuic, vanillic, syringic, syringaldehyde, gallic acids), hydroxycinnamic acid (trans-cinnamic, p-coumaric, caffeic, ferulic acids) and lignan (medioresinol). The predominant flavonoids were catechin/derivatives, with the highest content (78.56 mg/g) found in brown BGN. Trans-cinnamic and ferulic acids were dominant phenolic acid. Cotyledons of brown and brown-eyed BGN (317.71 and 378.59 µg/g) had the highest trans-cinnamic acid content, while red seeds had the highest ferulic acid (314.76 µg/g) content. Colored BGN had a significantly (p < 0.05) higher content of these components. Whole BGN contained significantly (p < 0.05) higher amount of flavonoids and phenolic acids, except for the trans-cinnamic acid. The rich flavonoid and phenolic acid content of BGN seeds highlights the fact that it is a good source of dietary phenolics with potential health-promoting properties.

Involvement of Mitophagy in Primary Cultured Rat Neurons Treated with Nanoalumina

The aim of this study was to explore the influence of the neurotoxicity of nanoalumina on primarily cultured neurons. Normal control, particle size control, aluminum, micron-alumina, and nanoalumina at 50-nm and 13-nm particle sizes were included as subjects to evaluate the level of apoptosis, necrosis, and autophagy in primarily cultured neurons and further explore the mitophagy induced by nanoalumina. The results demonstrated that nanoalumina could induce neuronal cell apoptosis, necrosis, and autophagy, among which autophagy was the most notable. When the autophagy inhibitor was added to the nanoalumina-treated group, it significantly downregulated the protein expression levels of Beclin-1 and LC3II/LC3. Observation under a transmission electron microscope and a fluorescence microscope revealed mitophagy characteristics induced by nanoalumina. Additionally, the neurotoxicological effects induced by nanoalumina were more significant than those induced by aluminum and in a particle size-dependent manner.

The therapeutic potential of γ-Al2O3 nanoparticle containing 5-fluorouracil in the treatment of colorectal cancer

5-Fluorouracil (5-FU) is being used in the treatment of several malignancies, but side effects are often reported and include: diarrhea, vomiting, nausea, poor appetite, watery eyes, and photophobia. We have developed and tested the cytotoxic activity of nanocrystalline powder of γ-alumina (γ-Al₂O₃) containing 5-FU in two-dimensional and three-dimensional (3D) CRC cell culture. γ-Al₂O₃ was prepared using a facile sol-gel method. The physicochemical properties of nanoparticles were investigated by Fourier Transform Infrared (FTIR) analysis, Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray Analysis (EDXA). Moreover, the particle size was monitored by Transmission Electron Microscopy (TEM). We used MTT and a scratch assay to assess the antiproliferative and anti-migratory of this agent. The effect of γ-Al₂O₃-5-FU on SOD, MDA, and total-thiols levels were evaluated. We assessed the expression of apoptotic markers in mRNA or proteins by RT-PCR and ELISA respectively. γ-Al₂O₃-5-FU inhibited cell growth in two-dimensional (2D) and three-dimensional (3D) cell culture and increased apoptosis as detected by DAPI stainning via modulation of caspases, BAx, BCl2 and cyclinD1. γ-Al₂O₃-5-FU also reduced the migratory activity of CRC cells relative to untreated controls. γ-Al₂O₃-5-FU increased the level of MDA, while reducing the level of SOD and total-thiols as well as inflamatory markers (e.g., TNF-s and IL-6). Our study demonstrated that γ-Al₂O₃-5-FU inhibited cell growth and migration, indicating its potential value in the treatment of colorectal cancer.

GANE can Improve Lung Fibrosis by Reducing Inflammation via Promoting p38MAPK/TGF-β1/NF-κB Signaling Pathway Downregulation

There is a trend to use nanoparticles as distinct treatments for cancer treatment because they have overcome many of the limitations of traditional drug delivery systems. Gallic acid (GA) is an effective polyphenol in the treatment of tissue injuries. In this study, GA was loaded onto niosomes to produce gallic acid nanoemulsion (GANE) using a green synthesis technique. GANE's efficiency, morphology, UV absorption, release, and Fourier-transform infrared spectroscopy (FTIR) analysis were evaluated. An in vitro study was conducted on the A549 lung carcinoma cell line to determine the GANE cytotoxicity. Also, our study was extended to evaluate the protective effect of GANE against lipopolysaccharide (LPS)-induced pulmonary fibrosis in rats. GANE showed higher encapsulation efficiency and strong absorption at 280 nm. Transmission electron microscopy presented a spherical shape of the prepared nanoparticles, and FTIR demonstrated different spectra for the free gallic acid sample compared to GANE. GANE showed cytotoxicity for the A549 carcinoma lung cell line with a low IC₅₀ value. It was found that oral administration of GANE at 32.8 and 82 mg/kg.b.w. and dexamethasone (0.5 mg/kg) provided significant protection against LPS-induced pulmonary fibrosis. GANE enhanced production of superoxide dismutase, GPx, and GSH. It simultaneously reduced the MDA level. The GANE and dexamethasone, induced the production of IL-4, but suppressed TNF-α and IL-6. On the other hand, the lung p38MAPK, TGF-β1, and NF-κB gene expression was downregulated in rats administrated with GANE when compared with the LPS-treated rats. Histological studies confirmed the effective effect of GANE as it had a lung-protective effect against LPS-induced lung fibrosis. It was noticed that GANE can inhibit oxidative stress, lipid peroxidation, and cytokines and downregulate p38MAPK, TGF-β1, and NF-κB gene expression to suppress the proliferation and migration of lung fibrotic cells.

Gallic acid inhibits celecoxib-induced mitochondrial permeability transition and reduces its toxicity in isolated cardiomyocytes and mitochondria

BACKGROUND

Mitochondria are the main target organelles through which drugs and chemicals exert their toxic effect on cardiomyocytes. The mitochondria-related mechanisms of celecoxib-induced cardiotoxicity have been extensively studied. Accumulated evidence shows natural molecules targeting mitochondria have proven to be effective in preventing cardiotoxicity.

PURPOSE

In the present study, we examined the ameliorative effect of gallic acid (GA) against celecoxib-induced cellular and mitochondrial toxicity in isolated cardiomyocytes and mitochondria.

RESEARCH DESIGN

The isolated cardiomyocytes and mitochondria were divided into various group, namely, control, celecoxib, celecoxib + GA (10, 50, and 100 µM). Several cellular and mitochondrial parameters such as cell viability, lipid peroxidation, succinate dehydrogenase (SDH) activity, reactive oxygen species (ROS) formation, mitochondrial membrane potential (MMP) collapse, and mitochondrial swelling were assessed in isolated cardiomyocytes and mitochondria.

RESULTS

Our results showed that administration of celecoxib (16 µg/ml) induced cytotoxicity and mitochondrial dysfunction at 6 h and 1 h, respectively, which is associated with lipid peroxidation intact cardiomyocytes, mitochondrial ROS formation, MMP collapse, and mitochondrial swelling. The cardiomyocytes and mitochondria treated with celecoxib + GA (10, 50, and 100 µM) significantly and dose-dependently restore the altered levels of cellular and mitochondrial parameters.

CONCLUSIONS

We concluded that GA through antioxidant potential and inhibition of mitochondrial permeability transition (MPT) pore exerted ameliorative role in celecoxib-induced toxicity in isolated cardiomyocytes and mitochondria. The data of the current study suggested that GA supplementation may reduce celecoxib-induced cellular and mitochondrial toxicity during exposure and may provide a potential prophylactic and defensive candidate for coxibs-induced mitochondrial dysfunction, oxidative stress, and cardiotoxicity.

Nanoparticles: Promising Tools for the Treatment and Prevention of Myocardial Infarction

Despite several recent advances, current therapy and prevention strategies for myocardial infarction are far from satisfactory, owing to limitations in their applicability and treatment effects. Nanoparticles (NPs) enable the targeted and stable delivery of therapeutic compounds, enhance tissue engineering processes, and regulate the behaviour of transplants such as stem cells. Thus, NPs may be more effective than other mechanisms, and may minimize potential adverse effects. This review provides evidence for the view that function-oriented systems are more practical than traditional material-based systems; it also summarizes the latest advances in NP-based strategies for the treatment and prevention of myocardial infarction.

M, Siva Sankar Reddy L, Dastagiri Reddy Y, Somasekhar G, Sirisha N, Nagaraju K, Shouib M, Rizwaan A. A new cerebral ischemic injury model in rats, preventive effect of gallic acid and in silico approaches

Current study was designed multiple occlusions and reperfusion of bilateral carotid arteries induced cerebral injury model and evaluated the protective effect of gallic acid on it. In silico study was involved to study gallic acid binding affinity on cerebrotonic proteins compared with standard drugs using Autodoc vina tool. Cerebral ischemia was induced by occlusion of bilateral common carotid arteries for 10 mins followed by 10 reperfusions (1 cycle), cycle was continued to 3 cycles (MO/RCA), then pathological changes were observed by estimation of brain antioxidants as superoxide dismutase, glutathione, catalase, oxidants like malonaldehyde, cerebral infarction area, histopathology, and study gallic acid treatment against cerebral injury. Gallic acid exhibited a strong binding affinity on targeted cerebrotoxic proteins. MO/RCA rat brain antioxidant levels were significantly decreased and increased MDA levels (p < 0.0001), Infarction size compared to sham rats. Gallic acid treatment rat brain MDA levels significantly decreased (p < 0.4476) and increased SOD (p < 0.0001), CAT (p < 0.0001), GSH (p < 0.0001), cerebral infarction area when compared to MO/RCA group. Developed model showed significant cerebral ischemic injury in rats, injury was ameliorated by Gallic acid treatment and in silico approaches also inhibit the cerebrotoxic protein function by targeting on active sites.

Protective Effects Induced by a Hydroalcoholic Allium sativum Extract in Isolated Mouse Heart

The aim of the present study was to investigate the possible protective effects of a garlic hydroalcoholic extract on the burden of oxidative stress and inflammation occurring on mouse heart specimens exposed to E. coli lipopolysaccharide (LPS), which is a well-established inflammatory stimulus. Headspace solid-phase microextraction combined with the gas chromatography-mass spectrometry (HS-SPME/GC-MS) technique was applied to determine the volatile fraction of the garlic powder, and the HS-SPME conditions were optimized for each of the most representative classes of compounds. CIEL*a*b* colorimetric analyses were performed on the powder sample at the time of delivery, after four and after eight months of storage at room temperature in the dark, to evaluate the color changing. Freshly prepared hydroalcoholic extract was also evaluated in its color character. Furthermore, the hydroalcoholic extract was analyzed through GC-MS. The extract was found to be able to significantly inhibit LPS-induced prostaglandin (PG) E₂ and 8-iso-PGF_2α levels, as well as mRNA levels of cyclooxygenase (COX)-2, interleukin (IL)-6, and nuclear factor-kB (NF-kB), in heart specimens. Concluding, our findings showed that the garlic hydroalcoholic extract exhibited cardioprotective effects on multiple inflammatory and oxidative stress pathways.

Nano-Medicine in the Cardiovascular System

Nano-medicines that include nanoparticles, nanocomposites, small molecules, and exosomes represent new viable sources for future therapies for the dysfunction of cardiovascular system, as well as the other important organ systems. Nanomaterials possess special properties ranging from their intrinsic physicochemical properties, surface energy and surface topographies which can illicit advantageous cellular responses within the cardiovascular system, making them exceptionally valuable in future clinical translation applications. The success of nano-medicines as future cardiovascular theranostic agents requires a comprehensive understanding of the intersection between nanomaterial and the biomedical fields. In this review, we highlight some of the major types of nano-medicine systems that are currently being explored in the cardiac field. This review focusses on the major differences between the systems, and how these differences affect the specific therapeutic or diagnostic applications. The important concerns relevant to cardiac nano-medicines, including cellular responses, toxicity of the different nanomaterials, as well as cardio-protective and regenerative capabilities are discussed. In this review an overview of the current development of nano-medicines specific to the cardiac field is provided, discussing the diverse nature and applications of nanomaterials as therapeutic and diagnostic agents.

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.

Activation of forkhead box O3a by mono(2-ethylhexyl)phthalate and its role in protection against mono(2-ethylhexyl)phthalate-induced oxidative stress and apoptosis in human cardiomyocytes

Mono(2-ethylhexyl)phthalate (MEHP), the active metabolite of di(2-ethylhexyl)phthalate (DEHP), is known to exert cardiotoxicity. The aim of the present study was to investigate the role of forkhead box O3a (FOXO3a) in MEHP-induced human AC16 cardiomyocyte injuries. MEHP reduced cell viability and mitochondrial membrane potential (ΔΨm), whereas it increased lactate dehydrogenase (LDH) leakage, production of reactive oxygen species (ROS), and apoptosis in cardiomyocytes. The expression of FOXO3a and its target genes, mitochondrial superoxide dismutase (Mn-SOD) and apoptosis repressor with caspase recruitment domain (ARC), increased after MEHP exposure, but the expression of p-FOXO3a protein was decreased. Overexpression of FOXO3a decreased the production of ROS and the apoptosis rate induced by MEHP, and the expression of Mn-SOD and ARC was further increased after MEHP exposure. In contrast, knockdown of FOXO3a resulted in increased ROS production and apoptosis and suppressed the expression of Mn-SOD and ARC in the presence of MEHP. However, overexpression or knockdown of FOXO3a did not affect MEHP-induced loss of ΔΨm. In conclusion, the loss of ΔΨm and apoptosis are involved in MEHP-induced cardiomyocyte toxicity. Activation of FOXO3a defends against MEHP-induced oxidative stress and apoptosis by upregulating the expression of Mn-SOD and ARC in AC16 cardiomyocytes.

Alumina Ceramic Exacerbates the Inflammatory Disease by Activation of Macrophages and T Cells

(1) Background: Aluminum oxide (Al₂O₃) ceramic is one of the materials used for artificial joints, and it has been known that their fine particles (FPs) are provided by the wear of the ceramic. Al₂O₃ FPs have been shown to induce macrophage activation in vitro; however, the inflammatory effect in vivo has not been studied. (2) Methods: We examined the in vivo effect of Al₂O₃ FPs on the innate and adaptive immune cells in the mice. (3) Results: Al₂O₃ FPs promoted the activation of spleen macrophages; however, conventional dendritic cells (cDCs), plasmacytoid DCs (pDCs), and natural killer (NK) cells were not activated. In addition, increases in the CD4 and CD8 T cells was induced in the spleens of the mice treated with Al₂O₃ FPs, which differentiated into interferon-gamma (IFN-γ)-producing helper T1 (Th1) and cytotoxic T1 (Tc1) cells. Finally, the injection of Al₂O₃ FPs exacerbated dextran sulfate sodium (DSS)-induced inflammation in the colon, mediated by activated and increased number of CD4 and CD8 T cells. (4) Conclusions: These data demonstrate that FPs of Al₂O₃ ceramic may contribute to the exacerbation of inflammatory diseases in the patients.

Does gallic acid improve cardiac function by attenuation of oxidative stress and inflammation in an elastase-induced lung injury?

Objective(s):

Cardiovascular disease has an important role in mortality caused by lung injury. Emphysema is associated with impaired pulmonary gas exchange efficiency and airflow limitation associated with small airway inflammation. The aim was to evaluate the interactions between lung injury, inflammation, and cardiovascular disease. Since gallic acid has antioxidant and anti-inflammatory effects, we hypothesized that gallic acid protects the lung and the related heart dysfunction in elastase-induced lung injury.

Materials and Methods:

Forty-eight Sprague-Dawley male rats were randomly divided into six groups: Control, Porcine pancreatic elastase (PPE) , PPE+GA, and 3 groups for different doses of gallic acid (GA 7.5, GA 15, GA 30 mg/kg). PPE was injected intra-tracheally on days 1 and 10 of the test. In each group, electrocardiography, hemodynamic parameters, oxidative stress, and bronchoalveolar lavage fluid were examined.

Results:

PPE administration showed a decrease in HR and QRS voltage of electrocardiogram parameters, as well as in hemodynamic parameters (P<0.05, P<0.01, and P<0.001) and superoxide dismutase (SOD) (P<0.05). Tumor Necrosis Factor α (TNF-α) (P<0.001), interleukin 6 (IL-6) (P<0.001), interleukin 6 (MDA) (P<0.001), and the total number of white blood cells (P<0.001) showed an increase in PPE groups. Gallic acid preserved the values of hemodynamic properties, oxidative stress, inflammation, and electrocardiogram parameters in comparison to the PPE group.

Conclusion:

Briefly, this study showed the valuable effect of gallic acid in cardiac dysfunction related to elastase-induced lung injury. These findings suggested that gallic acid, as a natural antioxidant, has a potential therapeutic effect on preventing oxidative stress, inflammation, and subsequent cardiovascular disease.

Impact of Gallic Acid on Gut Health: Focus on the Gut Microbiome, Immune Response, and Mechanisms of Action

Gallic acid (GA) is a naturally occurring polyphenol compound present in fruits, vegetables, and herbal medicines. According to previous studies, GA has many biological properties, including antioxidant, anticancer, anti-inflammatory, and antimicrobial properties. GA and its derivatives have multiple industrial uses, such as food supplements or additives. Additionally, recent studies have shown that GA and its derivatives not only enhance gut microbiome (GM) activities, but also modulate immune responses. Thus, GA has great potential to facilitate natural defense against microbial infections and modulate the immune response. However, the exact mechanisms of GA acts on the GM and immune system remain unclear. In this review, first the physicochemical properties, bioavailability, absorption, and metabolism of GA are introduced, and then we summarize recent findings concerning its roles in gastrointestinal health. Furthermore, the present review attempts to explain how GA influences the GM and modulates the immune response to maintain intestinal health.

Progressive impairment of learning and memory in adult zebrafish treated by Al2O3 nanoparticles when in embryos

Al₂O₃ Nanoparticles (Al₂O₃-NPs) have been widely used because of their unique physical and chemical properties, and Al₂O₃-NPs can be released into the environment directly or indirectly. Our previous research found that 13 nm Al₂O₃-NPs can induce neural cell death and autophagy in primarily cultured neural cells in vitro. The aim of this study was to determine where Al₂O₃-NPs at 13 nm particle size can cause neural cells in vivo and assess related behavioural changes and involved potential mechanisms. Zebrafish from embryo to adult were selected as animal models. Learning and memory as functional indicators of neural cells in zebrafish were measured during the development from embryo to adult. Our results indicate that Al₂O₃-NPs treatment in zebrafish embryos stages can cause the accumulation of aluminium content in zebrafish brain tissue, leading to progressive impaired neurodevelopmental behaviours and latent learning and memory performance. Additionally, oxidative stress and disruption of dopaminergic transmission in zebrafish brain tissues are correlated with the dose-dependent and age-dependent accumulation of aluminium content. Moreover, the number of neural cells in the telencephalon tissue treated with Al₂O₃-NPs significantly declined, and the ultramicroscopic morphology indicated profound autophagy alternations. The results suggest that Al₂O₃-NPs has dose-dependent and time-dependent progressive damage on learning and memory performance in adult zebrafish when treated in embryos. This is the first study of the effects of Al₂O₃-NPs on learning and memory during the development of zebrafish from embryo to adult.

Inhibitory effect of gallic acid on voltage-gated Na+ channels in rat cardiomyocytes

Gallic acid (GA) has a protective effect on the cardiovascular system. To study its cardiac electrophysiological effects, voltage-gated Na⁺ channel currents (I_Na ) were recorded in rat cardiomyocytes using whole-cell patch clamp techniques. Moreover, the effects of GA on aconitine-induced arrhythmias were assessed using electrocardiograms in vivo. We found that the current-voltage characteristic curve (I-V curve) of I_Na significantly shifted in the presence of 1, 3, and 10 μmol/L of GA. The peak sodium current density (I_Na -Peak) was reduced from -84.02 ± 5.68 pA/pF to -65.78 ± 3.96 pA/pF with 1 μmol/L, -54.45 ± 5.18 pA/pF with 3 μmol/L, and -44.20 ± 4.35 pA/pF with 10 μmol/L, respectively. GA shifted the steady-state activation curve of I_Na and recovery curve to the right and the steady-state inactivation curve to the left. The observed inhibitory effect was comparable to that of amiodarone. GA pre-treatment significantly prolonged the onset of fatal ventricular fibrillation. Our results indicated that GA inhibited I_Na in rat ventricular myocytes and aconitine-induced arrhythmias in vivo. These results suggest the potential of GA for development as a novel anti-arrhythmic therapeutic.

Comparative Analysis of the Developmental Toxicity in Xenopus laevis and Danio rerio Induced by Al2 O3 Nanoparticle Exposure

Engineered aluminum oxide nanoparticles (Al₂ O₃ NPs) having high-grade thermal stability and water-dispersion properties are extensively used in different industries and personal care products. Toxicological response evaluation of these NPs is indispensable in assessing the health risks and exposure limits because of their industrial disposal into the aquatic environment. We assessed and compared the developmental toxicity of Al₂ O₃ NPs in Xenopus laevis and Danio rerio over a period of 96 h using the frog embryo teratogenic assay Xenopus and a fish embryo toxicity assay. Engineered Al₂ O₃ NP exposure produced dose-dependent embryonic mortality and decreased the embryo length, indicating a negative effect on growth. Moreover, Al₂ O₃ NPs induced various malformations, such as small head size, a bent/deformed axis, edema, and gut malformation, dose-dependently and altered the expression of heart- and liver-specific genes in both X. laevis and D. rerio, as revealed by whole-mount in-situ hybridization and reverse transcriptase polymerase chain reaction. In conclusion, the toxicological data suggest that Al₂ O₃ NPs are developmentally toxic and teratogenic and negatively affect the embryonic development of X. laevis and D. rerio. Our study can serve as a model for the toxicological evaluation of nanomaterial exposure on vertebrate development that is critical to ensure human and environmental safety. Environ Toxicol Chem 2019;38:2672-2681. © 2019 SETAC.

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.

Gallic acid protects particulate matter (PM10) triggers cardiac oxidative stress and inflammation causing heart adverse events in rats

Previous studies have shown that exposure to particulate matter (PM) increased variety of health problems, particularly cardiovascular diseases leading to premature mortality. The cardiac effects of particulate matter containing PM₁₀ include increased infarct size, decreased heart function, and increased arrhythmias in experimental ischemia-reperfusion models in rats. The aim of this study was to evaluate the effects of particles with an aerodynamic diameter smaller than 10 μm (PM₁₀) on isolated-rat heart and also to determine the efficacy of gallic acid (GA) as a preventive agent in oxidative damage. The healthy rats were divided into 8 equal groups which served as, control, GA, PM₁₀ (0.5, 2.5, and 5 mg/kg), and PM₁₀+GA groups. PM₁₀ administered into the lungs via the trachea in two stages with 48-h interval. After all experiments, the electrocardiogram was recorded. Then, the hemodynamic parameters and ventricular arrhythmias in rat isolated-hearts were assessed using Langendorff apparatus and according to the Lambeth conventions. In addition, the inflammation and oxidative stress factors in cardiac tissues were evaluated in all groups. The obtained results showed that the exposure to PM caused to decrease in cardiac hemodynamic and electrocardiogram parameters. Also, in PM₁₀ rat groups, the IL-6, TNF-α, and oxidative stress parameters were increased. Gallic acid preserved the value of cardiac parameters and inflammation in rat hearts. In summary, we added a novel therapeutic effect of gallic acid for cardiac dysfunction induced by particulate matter. These findings could be related to antioxidant and antiinflammation properties and the obtained results suggest that natural antioxidant like gallic acid could be a therapeutic agent in prevention and management of health issues in the polluted areas of the world.

Alumina nanoparticles size and crystalline phase impact on cytotoxic effect on alveolar epithelial cells after simple or HCl combined exposures

Applications using alumina nanoparticles (Al₂O₃ NPs) have incredibly increased in different fields of activity. In defense and aerospace fields, solid composite propellants use leads to complex combustion aerosols emissions containing high concentrations of Al₂O₃ NPs and hydrogen chloride gas (HCl). To better characterize potential hazard resulting from exposure to these aerosols, this study assesses cytotoxic effects of mixtures containing both compounds on human pulmonary alveolar epithelial cells (A549 cell line) after 24 h exposures. After all co-exposures cell viability was >80%. However co-exposures decrease normalized real-time cell index. Significant decreases of intracellular reduced glutathione pool were also observed after co-exposures to γ-10 nm or γ/δ-13 nm Al₂O₃ NPs and HCl. Co-incubations with γ/δ-13 nm or γ-500 nm Al₂O₃ particles and HCl induced significant DNA double-strand breaks increases. Moreover all co-exposures and HCl alone disrupted cell cycle (increased G1 phase cells). Transmission Electron Microscopy (TEM) observations revealed γ/δ-13 nm Al₂O₃NPs adsorption and internalization in cell cytoplasm only, suggesting indirect genotoxic effects. According to our results Al₂O₃ particles/HCl mixtures can induce cytotoxic effects and Al₂O₃ size and crystallinity are two main parameters influencing cytotoxic mechanisms.

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.

Potentials of combining nanomaterials and stem cell therapy in myocardial repair

Cardiac diseases have become the leading cause of death worldwide. Developing efficient strategies to treat such diseases is of great urgency. Stem cell-based regeneration medicine offers a novel approach for heart repair. However, low retention and poor survival rate of engrafted cells limit its applications. Nanomaterials have shown great potentials in addressing above issues due to nanoparticles-bio interactions. Therefore, combining nanomaterials and stem cell therapy is of great interest and significance for heart repair. Herein, we provide a comprehensive understanding of the applications of four types of nanomaterials (nanogels, polymeric nanomaterials, inorganic nanomaterials and exosomes) in stem cell therapy for myocardial repair. In addition, we launch an initial discussion on current problems and more importantly, possible solutions for myocardial repair.

Ameliorative effects of gallic acid on gentamicin-induced nephrotoxicity in rats

The major side effect of gentamicin (GEN) is nephrotoxicity which in turn restricts the clinical use of this drug. In this study, the effect of gallic acid (GA) on gentamicin-induced nephrotoxicity was studied. A total number of 28 male Wistar rats were randomly divided into four experimental groups: control, GEN (100 mg/kg/day), GEN + GA (30 mg/kg/day), GA (30 mg/kg/day). All drug administrations were done intraperitoneally (i.p) for eight consecutive days. Twenty-four hours after the last administration, blood samples were collected to determine serum creatinine (Cr), blood urea nitrogen (BUN). The right kidney was used for histological examination. Malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) levels and catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activity were assayed in left renal tissue. Results showed a significant increase in the levels of MDA, NO, Cr, and BUN and decrease of GSH, CAT, GPx, and SOD by GEN administration. Co-administration with GA showed reduction in the levels of MDA, NO, Cr, and BUN and increase in GSH, CAT, GPx, and SOD. Also, the nephroprotective effect of GA was confirmed by the histological examination of the kidneys. The results of our study showed that GA exerts a significant nephroprotective effect against GEN-induced nephrotoxicity.

Silica nanoparticles promote oxLDL-induced macrophage lipid accumulation and apoptosis via endoplasmic reticulum stress signaling

Oxidized low-density lipoprotein (oxLDL), a marker of hyperlipidemia, plays a pivotal role in the development of atherosclerosis through the induction of macrophage-derived foam cell formation and thereafter apoptosis. Previous studies have indicated that silica nanoparticle (SiNPs) may exert a proatherogenic role, which could induce endothelial dysfunction, and monocytes infiltration. However, little is known about SiNPs' effects on macrophage-derived foam cell formation and apoptosis in the pathogenesis of atherosclerosis. In this study, we investigated the effects of SiNPs and oxLDL coexposure on macrophage-derived lipid metabolism, foam cell and apoptosis by using Raw264.7 cells. As a result, SiNPs enhanced cytotoxicity, apoptosis, and lipid accumulation upon oxLDL stimulation. Furthermore, quantitative determination of the expression levels of genes involved in cholesterol influx or efflux showed significantly up-regulated expressions of CD36 and SRA, whereas down-regulated expressions of ATP-binding cassette A1 (ABCA1), ABCG1, and SRB1 in oxLDL-treated macrophages, especially upon the co-exposure with SiNPs. It indicated that SiNPs promoted lipid accumulation in macrophage cells through not only facilitating cholesterol influx but also inhibiting cholesterol efflux. Endoplasmic reticulum (ER) is specialized for the production, modification, even trafficking of lipids. Interestingly, ER response was triggered upon oxLDL treatment, while SiNPs coexposure augmented the ER stress. Taken together, our results revealed that SiNPs promoted oxLDL-induced macrophage foam cell formation and apoptosis, which may be mediated by ER stress signaling. Thus we propose future researches needed for a better understanding of NPs' toxicity and their interactions with various pathophysiological conditions.

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 and Dodecyl Gallate Prevents Carbon Tetrachloride-Induced Acute and Chronic Hepatotoxicity by Enhancing Hepatic Antioxidant Status and Increasing p53 Expression

Gallic acid (3,4,5-trihydroxybenzoic acid, GA), a natural phenolic acid has been reported as a strong antioxidant. Therefore the present study was designed to evaluate the effects of GA and dodecyl gallate (DGA) against acute and chronic carbon tetrachloride (CCl₄)-induced hepatotoxicity. For acute model, rats were orally treated with GA and DGA for 7 d prior to CCl₄ by intraperitoneally (i.p.) injection. For the chronic model, rats were orally treated with GA or DGA and CCl₄ i.p. twice a week for four weeks. In both acute and chronic models, the CCl₄-treated groups showed significantly increase in serum hepatic enzyme activities and histopathologic alterations, as well as a disruption in antioxidative status. In contrast, the treatment with GA and DGA restored serum hepatic enzymes activities, improved histopathologic alterations, increased glutathione (GSH) and decreased lipid peroxidation levels. The activities of liver antioxidant enzymes were increased by GA and DGA only in acute model. The expression of p53 gene increased about 3.5 times after GA and DGA treatments, which could result in cell death of damaged hepatocytes preventing of a lifelong liver failure. Thus, these results suggest that GA and DGA has the potential to prevent liver damages as the case of fibrosis condition.

Gallic acid increases atrial natriuretic peptide secretion and mechanical dynamics through activation of PKC

AIMS

Gallic acid (GA) protects against myocardial ischemia-reperfusion (I/R) injury, prevents cardiac hypertrophy and fibrosis, and has anti-inflammatory activity in the heart. However, its effects in regulating atrial natriuretic peptide (ANP) secretion are unknown. The aim of this study was to determine the function of GA in regulating ANP secretion and atrial dynamics in rat atria.

KEY FINDINGS

GA (0.01, 0.05, and 0.1μmol/L) significantly increased atrial ANP secretion and induced positive inotropy dose-dependently. GA (0.1μmol/L) also increased plasma level of ANP and hemodynamics in rats. These effects were accompanied by upregulation of atrial protein kinase C subtypes β and ε (PKC_β and PKC_ε), which was completely blocked by LY333531 and EAVSLKPT, antagonists of protein PKC_β and PKC_ε, respectively. GA-induced ANP secretion was also attenuated by Gö6983 but not rottlerin, antagonists of PKC_α and PKC_δ, and the positive inotropy was reversed by Gö6983. U-73122, a phospholipase C (PLC) antagonist, mitigated the effects of GA on ANP secretion and mechanical dynamics and downregulated Phospho-PLC_β at Ser⁵³⁷ (pPLC_β S537), Phospho-PLC_β at Ser¹¹⁰⁵ (pPLC_β S1105), PKC_β and PKC_ε levels, whereas KN62, an inhibitor of Ca²⁺/calmodulin-dependent kinase II, was not modified the GA-induced ANP secretion and suppressed GA-induced mechanical dynamics.

SIGNIFICANCE

GA promotes ANP secretion and effects positive inotropy with regard to mechanical dynamics through the activation of PLC-PKC signaling in rat atria.