Protective role of gallic acid on sodium fluoride induced oxidative stress in rat brain

Gallic acid attenuates lipopolysaccharide - induced memory deficits, neurochemical changes, and peripheral alterations in purinergic signaling

Neuroinflammation is associated with many neurological disorders. Gallic acid (GA) has attracted significant attention due to its biological properties, such as neuroprotective, anti-inflammatory, and antioxidant effects. In this study, we evaluated the effects of GA in memory, TNF-α levels, oxidative stress, and activities of acetylcholinesterase (AChE), Na+, K+-ATPase and Ca2+-ATPase in the brain of mice exposed to lipopolysaccharide (LPS). Additionally, we evaluated alterations in adenine nucleotides and nucleosides in the serum. Male mice were orally pretreated with vehicle or GA (50 or 100 mg/kg) for 14 days. Between days 8 and 14, the animals also received LPS injection (250 µg/kg) or saline. At the end of the experimental protocol, the animals were submitted to object recognition test, euthanized and cerebral cortex, hippocampus, striatum and blood were collected. LPS induced memory deficits, which were prevented by GA treatment. GA protected against LPS-induced oxidative damage in the cerebral cortex, hippocampus and striatum by reducing reactive oxygen species and nitrite levels, while increasing total thiol content and activities of antioxidant enzymes. GA also prevented LPS-induced alterations in AChE, Na+, K+-ATPase, and Ca2+-ATPase activities in brain structures. LPS elevated TNF-α levels in the hippocampus and cerebral cortex, which were attenuated by GA treatment. Furthermore, LPS caused a reduction in ADP and AMP hydrolysis and an increase in adenosine deamination in the serum, which were also prevented by GA. The effects of GA against neuroinflammation may be attributed to its potent antioxidant and anti-inflammatory properties, which modulate various pathways, including those involved in memory mechanisms.

Ameliorative effects of gallic acid on tebuconazole-induced adverse effects in the cerebellum of adult albino rats: histopathological and immunohistochemical evidence

Tebuconazole (TEB) is a common triazole sterol demethylation inhibitor fungicide utilized to manage a variety of diseases in crops like cereals, fruits, and vegetables. The aim of this work was to assess the effects of TEB on the structure of the cerebellum in adult albino rats and possible protective impact of co-administration of Gallic acid (GA). Four groups of forty adult male albino rats were randomly selected, and the rats in group I received corn oil through daily gavage for 4 weeks. Group II received GA dissolved in the normal saline at a dose of 100 mg/kg through daily gavage for 4 weeks, group III administered with TEB dissolved in corn oil at its acceptable daily intake dose (0.02 mg/kg body weight) through daily gavage for 4 weeks, group IV rats received both TEB and GA. For light microscopic, ultrastructural, and immunohistochemical investigations, cerebellar specimens were prepared. TEB exposure led to neuronal damage in the form of degenerated Purkinje cells with vacuolated cytoplasm, areas of lost Purkinje cells, the basket cells appeared vacuolated with degenerated neuropil, the granule cells clumped with congested areas between them, dilated cerebellar islands, weak positive bcl2 immunoreactions in the Purkinje cells, and numerous GFAP-positive astrocytes. GA mitigated TEB-mediated histological changes in the cerebellar cortex. We concluded that TEB caused Purkinje neurons in the rat cerebellar cortex to degenerate and undergo apoptosis. GA had a neuroprotective benefit against TEB toxicity in the rat cerebellar cortex.

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 Review on Experimentally Proven Medicinal Plants and Their Constituents against Fluoride Toxicity

Fluoride toxicity, principally by polluted groundwater, is regarded as a momentous global public health risk, as there is no particular and proven treatment for chronic fluoride toxicity i.e., fluorosis which leads to several serious health complications. Scientific literature reveals several medicinal plants and natural products alleviate experimentally induced fluoride toxicity. The present review attempts to collate those experimental studies on medicinal plants and plant derived natural products with fluoride toxicity ameliorative effects. Literature scrutiny was performed by using online bibliographic databases and the studies for the last 15 years were considered. Minerals and semi-synthetic or synthetic analogs of natural products were excluded. Literature study revealed that 25 medicinal plants and 17 natural products exhibited significant protection from fluoride toxicity in experimental animal models i.e., preclinical studies. Two clinical studies on medicinal plants were also found in literature showing beneficial yet poorly correlated outcome. Relevant research in this field could lead to development of a potentially useful agent in therapeutic management of fluoride toxicity in humans.

Distribution of Fluoride in Plasma, Brain, and Bones and Associated Oxidative Damage After Induced Chronic Fluorosis in Wistar Rats

The study was aimed to determine fluoride levels in plasma, brain, and bones of Wistar rats following chronic administration of fluoride at different dose levels and the consequent oxidative damage inflicted in these tissues. Brain histomorphology and bone radiographs were also evaluated to assess the extent of damage in these organs. Eighteen rats were randomly divided into three groups with six animals in each group. Group I served as control and groups II and III received 50 and 100 ppm fluoride in tap water, respectively for 180 days. A dose-dependent rise in the levels of fluoride in plasma, brain, and bones was observed in rats. Significant (P < 0.05) alterations in levels of total thiols, glutathione peroxidase, glutathione reductase, acetylcholinesterase, catalase, superoxide dismutase, lipids, as well as protein peroxidation in blood and brain were observed as compared to control in a dose-dependent manner. Radiological examination of bone revealed thinning of bone cortex with haphazard ossification, reduced bone density, and widening of marrow cavity indicating occurrence of flawed bone remodeling upon chronic fluoride exposure. Improper mineralization in bones of intoxicated rats indirectly reflected reduced bone tensile strength. Moreover, alterations in plasma Ca:P ratio and high levels of fluoride in bone ash indicated that chronic fluoride exposure leads to alterations in the bone matrix further corroborating the radio-graphical findings. Additionally, severe microscopic alterations were recorded in the cerebrum and cerebellum of treated rats which included neuronal necrosis, gliosis, spongiosis, perivascular cuffing, congestion, and hemorrhage which correlated well with oxidative changes induced by fluoride intoxication in the brain tissue of rats.

Effects of gallic acid and Zn, Cu, and Ni on antioxidant enzyme activities of Hyphantria cunea larvae infected with Bacillus thuringiensis

The effects of copper, nickel, and zinc and the potent antioxidant gallic acid on the antioxidant enzyme activities of Hyphantria cunea larvae infected with Bacillus thuringiensis subsp. kurstaki have been identified in this study. With metal exposure, all the enzyme activities have increased. Antagonistic effects were observed in the combination of gallic acid with all three metals on the activities of superoxide dismutase and catalase. In glutathione peroxidase activity, an antagonistic effect was observed in gallic acid plus nickel group, while there was a synergistic effect for gallic acid plus zinc and gallic acid plus copper. Activities of these enzymes in larvae exposed only to the metals increased in the infected groups; while exposure to gallic acid alone elicited a decrease. As a consequence, it was found that enzyme activities were affected by both metals and gallic acid and infection.

Antioxidant Phytochemicals for the Prevention of Fluoride-Induced Oxidative Stress and Apoptosis: a Review

Fluorosis is a major public health problem globally. The non-availability of specific treatment and the irreversible nature of dental and skeletal lesions poses a challenge in the management of fluorosis. Oxidative stress is known to be one of the most important mechanisms of fluoride toxicity. Fluoride promotes the accumulation of reactive oxygen species by inhibiting the activity of antioxidant enzymes, resulting in the excessive production of reactive oxygen species at the cellular level which further leads to activation of cell death processes such as apoptosis. Phytochemicals that act as antioxidants have the potential to protect cells from oxidative stress. Evidence confirms that clinical symptoms of fluorosis can be mitigated to some extent or prevented by long-term intake of antioxidants and plant products. The primary purpose of this review is to examine recent findings that focus on the amelioration of fluoride-induced oxidative stress and apoptosis by natural and synthetic phytochemicals and their molecular mechanisms of action.

Galla Chinensis, a Traditional Chinese Medicine: Comprehensive review of botany, traditional uses, chemical composition, pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Galla chinensis (GC), a traditional Chinese medicine (TCM), has a wide range of pharmacological properties which have been widely used for more than 1400 years. Based on shape, GC is divided into two groups: jiaobei and dubei. It is a bitter, sour, cold and astringent substance which is usually used for treating diarrhea, constipation, bleeding, cough, vomiting, sweating, hemorrhoids, and anal and uterine prolapse. It is distributed in Japan, North Korea, and all parts of China.

AIM OF STUDY

This study was aimed at carrying out a comprehensive overview of the current status of research on Galla chinensis (GC) for better understanding of it characteristics, while providing a clear direction for future studies. It has aroused the interest of researchers, leading to development of medicinal value, expansion of its application, and provision of wider and more effective drug choices. This study was focused on the traditional uses, botany, chemical composition, pharmacology and toxicology of GC. Finally, the study focused on possible future research directions for GC.

MATERIALS AND METHODS

A comprehensive analysis was done based on academic papers, pharmaceutical monographs, ancient medicinal works, and drug standards of China. This review used Galla and Galla chinensis as keywords for retrieval of information on GC from online databases such as PubMed, Elsevier, CNKI, Web of Science, Google Scholar, SCI hub, and Baidu academic.

RESULTS

It was found that the chemical constituents of GC included tannins, phenolic acid, amino acids and fatty acid, with polyphenol compounds (especially tannins and gallic acid) as the distinct components. In vitro and in vivo studies revealed that GC exerted numerous biological effects such as anti-caries, antibacterial, antiviral, anticancer, and antioxidant effects. The therapeutic effect of GC was attributed mainly to the biological properties of its bioactive components.

CONCLUSIONS

GC is an important TCM which has potential benefit in the treatment of a variety of diseases. However, the relationship amongst the structure and biological activity of GC and its components, mechanism of action, toxicity, pharmacokinetics and target organs need to be further studied. Quality control and quality assurance programs for GC need to be further developed. There is need to study the dynamics associated with the accumulation of chemical compounds in GC as well as the original plants and aphid that form GC.

Gallic acid attenuates blood-spinal cord barrier disruption by inhibiting Jmjd3 expression and activation after spinal cord injury

After spinal cord injury (SCI), blood-spinal cord barrier (BSCB) disruption results in secondary injury including apoptotic cell death of neurons and oligodendrocytes, thereby leads to permanent neurological deficits. Recently, we reported that the histone H3K27me3 demethylase Jmjd3 plays a role in regulating BSCB integrity after SCI. Here, we investigated whether gallic acid (GA), a natural phenolic compound that is known to be anti-inflammatory, regulates Jmjd3 expression and activation, thereby attenuates BSCB disruption following the inflammatory response and improves functional recovery after SCI. Rats were contused at T9 and treated with GA (50 mg/kg) via intraperitoneal injection immediately, 6 h and 12 h after SCI, and further treated for 7 d with the same dose once a day. To elucidate the underlying mechanism, we evaluated Jmjd3 activity and expression, and assessed BSCB permeability by Evans blue assay after SCI. GA significantly inhibited Jmjd3 expression and activation after injury both in vitro and in vivo. GA also attenuated the expression and activation of matrix metalloprotease-9, which is well known to disrupt the BSCB after SCI. Consistent with these findings, GA attenuated BSCB disruption and reduced the infiltration of neutrophils and macrophages compared with the vehicle control. Finally, GA significantly alleviated apoptotic cell death of neurons and oligodendrocytes and improved behavior functions. Based on these data, we propose that GA can exert a neuroprotective effect by inhibiting Jmjd3 activity and expression followed the downregulation of matrix metalloprotease-9, eventually attenuating BSCB disruption after SCI.

Nutritional supplementation of gallic acid ameliorates Alzheimer-type hippocampal neurodegeneration and cognitive impairment induced by aluminum chloride exposure in adult Wistar rats

Prolonged exposure to aluminum through occupational hazards or food/water intake has been linked to the occurrence of Alzheimer's disease (AD). This study aimed at investigating the neuroprotective effects of Gallic Acid (GA) against aluminum-chloride induced AD in adult Wistar rats. Twenty eight (28) adult Wistar rats were divided into four groups (n = 7). Group A received normal saline as placebo; Group B received 200 mg/kg bw of AlCl₃ only; Group C received 100 mg/kg bw of GA only and group D received 100 mg/kg bw of GA and 200 mg/kg bw of AlCl₃. At the end of the 60 days experiment, blood samples were collected to obtain serum for analysis and the brain was harvested. Neurobehavioural tests (Morris Water maze, Y-Maze), neurotransmitter levels, oxidative stress markers, serum electrolytes, antioxidant enzymes and histological assessment were carried out. There was a significant decrease in antioxidant enzymes (CAT, GSH and SOD), serum electrolyte (except K+) and neurotransmitter levels (except norepinephrine) with corresponding increase in stress markers (MDA, H₂O₂ and NO) among group B compared to control but was restored nearly to normal after GA administration. Neurobehavioral tests showed decreased spatial memory impairment and learning deficit in group B compared to control but was ameliorated with GA administration. Histological observation showed neurofibrillary tangles and amyloid plaques in the external granular layer of group B but protected by GA administration. Nutritional supplementation of GA preserve the morphological and physiological integrity of the hippocampus against environmental neurotoxins (AlCl₃) by mopping up free radicals associated with oxidative stress induced AD.

Wild Italian Prunus spinosa L. Fruit Exerts In Vitro Antimicrobial Activity and Protects Against In Vitro and In Vivo Oxidative Stress

Polyphenol-rich foods could have a pivotal function in the prevention of oxidative stress-based pathologies and antibacterial action. The purpose of this study was to investigate the in vitro antimicrobial activity, as well as the in vitro and In Vivo antioxidant capacities of wild Prunus spinosa L. fruit (PSF) from the southeast regions of Italy. The total phenolic content (TPC) was quantified, and the single polyphenols were analyzed by HPLC-DAD, showing high rutin and 4-hydroxybenzoic acid levels, followed by gallic and trans-sinapic acids. PSF extract demonstrated antimicrobial activity against some potentially pathogenic Gram-negative and Gram-positive bacteria. Besides, we investigated the cellular antioxidant activity (CAA) and the hemolysis inhibition of PSF extract on human erythrocytes, evidencing both a good antioxidant power and a marked hemolysis inhibition. Furthermore, an In Vivo experiment with oxidative stress-induced rats treated with a high-fat diet (HFD) and a low dose of streptozotocin (STZ) demonstrated that PSF has a dose-dependent antioxidant capacity both in liver and in brain. In conclusion, the wild Italian Prunus spinosa L. fruit could be considered a potentially useful material for both nutraceutical and food industries because of its antioxidant and antimicrobial effects.

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 rat liver mitochondria ex vivo from bisphenol A induced oxidative stress mediated damages

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Bisphenol A induces oxidative stress mediated liver mitochondrial damage.

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Bisphenol A induced damage is being protected when mitochondria are co-incubated with gallic acid.

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Scanning electron microscopy of mitochondrial tomography supports the biochemical observations.

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Gallic acid may be used as future remedial measure for the protection of bisphenol A induced damages of liver mitochondria.

Humans are often exposed to bisphenol A (BPA), the monomer of polycarbonate plastics and epoxy resins, through BPA contaminated drinking water, beverages and foods, packaged in polycarbonate plastic bottles and cans coated with epoxy resins due to leaching. Several research groups have reported that BPA may cause damage of mitochondria in liver, kidney, heart and brain cells by inducing oxidative stress. The antioxidant efficacy of gallic acid (GA), a polyphenol compound obtained from plants, against different toxicants induced oxidative stress has been well established. The aim of the present study was to examine the protective efficacy of GA against BPA induced oxidative damages of the rat liver mitochondria ex vivo. In our study, we have found a significant decrease in the intactness of mitochondria; a significant increase (P ≤ 0.001) in the levels of lipid peroxidation end product (i.e. malondialdehyde) and protein carbonylation product; and also a significant decrease (P ≤ 0.001) in the reduced glutathione content; when mitochondria were incubated with BPA (160 μM/ml) only. These results indicate that BPA probably causes damage to the cellular macromolecules through oxidative stress. We have observed significant counteractions (P ≤ 0.001) against BPA induced alterations in mitochondrial intactness, lipid peroxidation and protein carbonylation products formation and reduced glutathione content when mitochondria were incubated with BPA and GA (20 μg/ml/ 40 μg/ml/ 80 μg/ml) in combination in a dose-dependent manner. Gallic acid also showed significant restorations (P ≤ 0.001) of the activities of antioxidant enzymes, Krebs cycle enzymes, respiratory chain enzymes and thiolase when mitochondria were incubated with BPA and dosage of GA (20 μg/ml/ 40 μg/ml/ 80 μg/ml) in combination compared to BPA incubated mitochondria. Furthermore, GA significantly (P ≤ 0.001) counteracted the BPA induced decrease in tryptophan and NADH auto-fluroscence levels in mitochondria. This result suggests that GA protects the mitochondria probably by reducing the oxidative stress. Besides, GA protects the mitochondrial surface from BPA induced oxidative damages as viewed under the scanning electron microscope. Considering all the results, it can be concluded that GA shows potent efficacy in protecting the rat liver mitochondria ex vivo from BPA induced oxidative stress mediated damages.

Synergistic oxidative impact of aluminum chloride and sodium fluoride exposure during early stages of brain development in the rat

Aluminum is widely used in industry and in cooking utensils, especially in countries with low economic and social standards. Fluoride is also used in industry, a major component of toothpaste and is added to the drinking water in many countries to fight teeth decay and cavities. Consequently, the coexistence of aluminum and fluoride is highly probable. Growing evidence indicates that environmental pollutants during the early stages of embryonic development may reprogram the offspring's brain capabilities to encounter oxidative stress during the rest of their postnatal life. This study investigated the impact of sodium fluoride (NaF, 0.15 g/L) and aluminum chloride (AlCl₃, 500 mg/L) added, individually or in combination, to the deionized drinking water starting from day 6 of gestation until just after weaning, or until the age of 70 days postnatal life. A significant decline was observed in tissue contents of vitamin C, reduced glutathione, GSH/GSSH ratio, and the total protein, as well as in the activities of Na⁺/K⁺-ATPase and superoxide dismutase (SOD) in almost all cases. On the contrary, lipid peroxidation and NO, as total nitrate, exhibited a significant increase in comparison with the corresponding control. Based on the present results, administration of Al and NaF, alone or in combination abated the quenching effects of the antioxidant system and induced oxidative stress in most brain regions under investigation. In conclusion, aluminum and fluoride are very noxious environmental pollutants that interfere with the proper functions of the brain neurons and their combination together aggravates their hazard.

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.

Gallic acid influence on bovine serum albumin thermal stability

A thermoanalytical approach reveals the dual action of GA on BSA thermal stability.

Improving Anti-Cancer Potentiality and Bioavailability of Gallic Acid by Designing Polymeric Nanocomposite Formulation

Objective:

In this study, we investigated the in vivo antitumor activity and pharmacokinetic characteristics of encapsulated GA-NC (gallic acid nanocomposite) in normal and hepatocellular carcinoma (HCC)-induced rats.

Methods:

Rats were distributed into 4 groups; negative control, HCC, gallic acid (GA), and GA-NC. Serum levels of alpha-fetoprotein (AFP), endoglin (ENG), heat shock protein-70 (HSP-70), pro-caspase 3, lipocalin-2 (LCN-2) and β-cell leukemia/lymphoma 2 (Bcl-2) were assayed by ELISA. The pharmacokinetic parameters for GA or GA-NC were determined by means of non-compartmental approach based on the serum– concentration profiles of free GA and GA-NC after oral administration. Also, histological procedures were used for examination of liver tissue sections.

Results:

Anaplastic changes in liver tissues were observed in untreated HCC group, as well as a significant increase in the serum AFP level. In addition, significant elevation in the serum ENG level as an angiogenic marker and the serum levels of the apoptotic mediators; HSP-70, Bcl-2 and pro-caspase 3 beside significant amplification in the serum inflammatory modulator, LCN-2 were recorded. Treatment with free GA or GA-NC markedly recovered the anaplastic changes in the rat liver tissues. In addition, they restored serum levels of AFP, ENG, HSP-70, Bcl-2, pro-caspase-3, and LCN-2. Pharmacokinetic analysis revealed that GA–NC displayed a characteristic sustained release profile with 4-fold increase in bioavailability in normal and HCC-induced rats.

Conclusions:

The results of this study suggest that encapsulation of GA into PLGA-CS-PEG enhances its oral bioavailability and anti-cancer activity. GA-NC may be a new therapeutic candidate for the mitigation of hepatocarcinogenesis.

EPR spectral investigation of radiation-induced radicals of gallic acid

In the present work, spectroscopic features of the radiation-induced radicals of gallic acid compounds were investigated using electron paramagnetic resonance (EPR) spectroscopy. While un-irradiated samples presented no EPR signal, irradiated samples exhibited an EPR spectrum consisting of an intense resonance line at the center and weak lines on both sides. Detailed microwave saturation investigations were carried out to determine the origin of the experimental EPR lines. It is concluded that the two side lines of the triplet satellite originate from forbidden "spin-flip" transitions. The spectroscopic and structural features of the radiation-induced radicals were determined using EPR spectrum fittings. The experimental EPR spectra of the two gallic acid compounds were consistent with the calculated EPR spectroscopic features of the proposed radicals. It is concluded that the most probable radicals are the cyclohexadienyl-type, [Formula: see text] radicals for both compounds.

Plants-Derived Neuroprotective Agents: Cutting the Cycle of Cell Death through Multiple Mechanisms

Neuroprotection is the preservation of the structure and function of neurons from insults arising from cellular injuries induced by a variety of agents or neurodegenerative diseases (NDs). The various NDs including Alzheimer's, Parkinson's, and Huntington's diseases as well as amyotropic lateral sclerosis affect millions of people around the world with the main risk factor being advancing age. Each of these diseases affects specific neurons and/or regions in the brain and involves characteristic pathological and molecular features. Hence, several in vitro and in vivo study models specific to each disease have been employed to study NDs with the aim of understanding their underlying mechanisms and identifying new therapeutic strategies. Of the most prevalent drug development efforts employed in the past few decades, mechanisms implicated in the accumulation of protein-based deposits, oxidative stress, neuroinflammation, and certain neurotransmitter deficits such as acetylcholine and dopamine have been scrutinized in great detail. In this review, we presented classical examples of plant-derived neuroprotective agents by highlighting their structural class and specific mechanisms of action. Many of these natural products that have shown therapeutic efficacies appear to be working through the above-mentioned key multiple mechanisms of action.

Representative literature on the phytonutrients category: Phenolic acids

Research concerning the benefits derived from dietary polyphenols, a significant class within the family of phytonutrients, has increased considerably in the last decade. Prior to the late 1990s, the nutritional spotlight focused on the antioxidant capabilities of carotenoids, vitamins, and minerals. More recently, however, research has emerged in strong support of the antioxidant capacity of polyphenols and their role in the prevention and/or treatment of certain cancers, diabetes, cardiovascular diseases, and inflammation. Polyphenols are categorized according to the nature of their carbon skeleton, ranging from basic phenolic molecules to highly complex compounds, such as flavonoids, the most common and widely studied of all phenolic compounds. The most prevalent phenolic acids include ellagic acid, gallic acid, tannic acid, and capsaicin.

Post-Stroke Depression Modulation and in Vivo Antioxidant Activity of Gallic Acid and Its Synthetic Derivatives in a Murine Model System

Gallic acid (3,4,5-trihydroxybenzoic acid, GA) is a plant secondary metabolite, which shows antioxidant activity and is commonly found in many plant-based foods and beverages. Recent evidence suggests that oxidative stress contributes to the development of many human chronic diseases, including cardiovascular and neurodegenerative pathologies, metabolic syndrome, type 2 diabetes and cancer. GA and its derivative, methyl-3-O-methyl gallate (M3OMG), possess physiological and pharmacological activities closely related to their antioxidant properties. This paper describes the antidepressive-like effects of intraperitoneal administration of GA and two synthetic analogues, M3OMG and P3OMG (propyl-3-O-methylgallate), in balb/c mice with post-stroke depression, a secondary form of depression that could be due to oxidative stress occurring during cerebral ischemia and the following reperfusion. Moreover, this study determined the in vivo antioxidant activity of these compounds through the evaluation of superoxide dismutase (SOD) and catalase (Cat) activity, thiobarbituric acid-reactive substances (TBARS) and reduced glutathione (GSH) levels in mouse brain. GA and its synthetic analogues were found to be active (at doses of 25 and 50 mg/kg) in the modulation of depressive symptoms and the reduction of oxidative stress, restoring normal behavior and, at least in part, antioxidant endogenous defenses, with M3OMG being the most active of these compounds. SOD, TBARS, and GSH all showed strong correlation with behavioral parameters, suggesting that oxidative stress is tightly linked to the pathological processes involved in stroke and PSD. As a whole, the obtained results show that the administration of GA, M3OMG and P3OMG induce a reduction in depressive symptoms and oxidative stress.

Evaluation of antigout activity of Phyllanthus emblica fruit extracts on potassium oxonate-induced gout rat model

Aim:

The present study has been conducted to evaluate antigout activity of aqueous and alcoholic extracts of Phyllanthus emblica fruits following its 28 days repeated oral administration on potassium oxonate-induced gout rat model.

Materials and Methods:

The study was conducted on 42 male Sprague-Dawely rats dividing them in seven groups having six rats in each group. Groups I, II, and III served as vehicle control group, gout control group, and standard treatment control group, respectively. Rats of all the groups except vehicle control group were administered potassium oxonate at 250 mg/kg (IP), throughout the study period (28 days) for induction of gout. Groups IV and V received aqueous extract of P. emblica at 200 and 400 mg/kg, and Groups VI and VII received alcoholic extract of P. emblica at 200 and 400 mg/kg (daily oral for 28 days). At the end of study, all the rats were subjected to blood collection; blood and serum sample were analyzed for hematological and biochemical parameters, respectively. After collection of blood samples on the 29^th day, all the rats were sacrificed and subjected to post mortem examination to determine the presence or absence of gross and histopathological lesions in kidney tissues.

Results:

At the end of study, rats of gout control group showed increase in platelets counts, serum creatinine, uric acid, blood urea nitrogen (BUN), and xanthine oxidase (XO) enzyme level along with alterations in kidney tissues as compared to vehicle control group. Gouty rats treated with aqueous and alcoholic extracts of P. emblica at 200 and 400 mg/kg body weight and standard treatment allopurinol at 5 mg/kg body weight showed reduction in platelets counts, serum creatinine, uric acid, BUN, and XO enzyme level along with significant improvements in histological structure of kidney as compared to rats of gout control group.

Conclusion:

Oral administration of aqueous and alcoholic extracts of P. emblica fruits for 28 days has shown protection against gout in dose-dependent manner in rats.

Chamomile decoction extract inhibits human neutrophils ROS production and attenuates alcohol-induced haematological parameters changes and erythrocytes oxidative stress in rat

BACKGROUND

The aim of this study was to evaluate the protective effects of subacute pre-treatment with chamomile (Matricaria recutita L.) decoction extract (CDE) against stimulated neutrophils ROS production as well as ethanol (EtOH)-induced haematological changes and erythrocytes oxidative stress in rat.

METHODS

Neutrophils were isolated and ROS generation was measured by luminol-amplified chemiluminescence. Superoxide anion generation was detected by the cytochrome c reduction assay. Adult male wistar rats were used and divided into six groups of ten each: control, EtOH, EtOH + various doses of CDE (25, 50, and 100 mg/kg, b.w.), and EtOH+ ascorbic acid (AA). Animals were pre-treated with CDE extract during 10 days.

RESULTS

We found that CDE inhibited (P ≤ 0.0003) luminol-amplified chemiluminescence of resting neutrophils and N-formyl methionylleucyl-phenylalanine (fMLF) or phorbolmyristate acetate (PMA) stimulated neutrophils, in a dose-dependent manner. CDE had no effect on superoxide anion, but it inhibited (P ≤ 0.0004) H2O2 production in cell free system. In vivo, CDE counteracted (P ≤ 0.0034) the effect of single EtOH administration which induced (P < 0.0001) an increase of white blood cells (WBC) and platelets (PLT) counts. Our results also demonstrated that alcohol administration significantly (P < 0.0001) induced erythrocytes lipoperoxidation increase and depletion of sulfhydryl groups (-SH) content as well as antioxidant enzyme activities as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). More importantly, we found that acute alcohol administration increased (P < 0.0001) erythrocytes and plasma hydrogen peroxide (H2O2), free iron, and calcium levels while the CDE pre-treatment reversed increased (P ≤ 0.0051) all these intracellular disturbances.

CONCLUSIONS

These findings suggest that CDE inhibits neutrophil ROS production and protects against EtOH-induced haematologiacal parameters changes and erythrocytes oxidative stress. The haematoprotection offered by chamomile might involve in part its antioxidant properties as well as its opposite effect on some intracellular mediators such as H2O2, free iron, and calcium.

Gallic acid: a versatile antioxidant with promising therapeutic and industrial applications

Oxidative stress, a result of an overproduction and accumulation of free radicals, is the leading cause of several degenerative diseases such as cancer, atherosclerosis, cardiovascular diseases, ageing and inflammatory diseases.

Protective effect of resveratrol on fluoride induced alteration in protein and nucleic acid metabolism, DNA damage and biogenic amines in rat brain

Fluoride, a well-established environmental carcinogen, has been found to cause various neurodegenerative diseases in human. Sub-acute exposure to fluoride at a dose of 20mg/kgb.w./day for 30 days caused significant alteration in pro-oxidant/anti-oxidant status of brain tissue as reflected by perturbation of reduced glutathione content, increased lipid peroxidation, protein carbonylation, nitric oxide and free hydroxyl radical production and decreased activities of antioxidant enzymes. Decreased proteolytic and transaminase enzymes' activities, protein and nucleic acid contents and associated DNA damage were observed in the brain of fluoride intoxicated rats. The neurotransmitters dopamine (DA), norepinephrine (NE) and serotonin level was also significantly altered after fluoride exposure. Protective effect of resveratrol on fluoride-induced metabolic and oxidative dysfunctions was evaluated. Resveratrol was found to inhibit changes in metabolic activities restoring antioxidant status, biogenic amine level and structural organization of the brain. Our findings indicated that resveratrol imparted antioxidative role in ameliorating fluoride-induced metabolic and oxidative stress in different regions of the brain.

Gallic acid improves cognitive, hippocampal long-term potentiation deficits and brain damage induced by chronic cerebral hypoperfusion in rats

Abstract: Cerebral Hypoperfusion Ischemia (CHI) has important role in neuronal damage and behavioral deficits, including memory and Long-term Potentiation (LTP) impairment. Protective effects of Gallic Acid (GA) on memory, hippocampus LTP and cell viability were examined in permanent bilateral common carotid artery occlusion in rats. Animals were divided into 9 groups: Control (Cont); sham operated (Sho); Cerebral Hypoperfusion Ischemia (CHI); CHI received normal saline (CHI +Veh); CHI treated with different doses gallic acid (50, 100, 200 mg kg(-1) for 5 days before and 5 days after CHI induction, orally); CHI treated with phenytoin (50 mg kg(-1), ip) (CHI+Phe); and sham operated received 100 mg kg(-1), orally (Sho+GA100). CHI was induced by bilateral common carotid artery occlusion (2VO). Behavioral, electrophysiological and histological evaluations were performed. Data were analyzed by one-way and repeated measures ANOVA followed by tukey's post-hoc test. GA improved passive avoidance memory, hippocampal LTP and cell. viability in hippocampus and cortex of ischemic rats significantly (p < 0.01). The results suggest that gallic acid via its antioxidative and free radicals scavenging properties attenuates CHI induced behavioral and electrophysiological deficits and has significant protective effect on brain cell viability. Dose of 100 mg kg(-1) GA has affected the ischemic but not intact rats and its effect was more potent significantly than phenytoin, a routine drug for ischemic subjects.

Antioxidant effect of Phyllanthus emblica extract prevents contrast-induced acute kidney injury

Background

Contrast-induced acute kidney injury (CI-AKI) occurs after the administration of intravenous iodinated contrast agents. Oxidative stress has been proposed as one of the most important mechanisms in the pathogenesis of CI-AKI. The objective of this study was to investigate the antioxidant effect of the extract from Phyllanthus emblica (PE) in preventing CI-AKI.

Methods

Male Sprague Dawley rats were subjected into eight groups, were given water (control) or PE extract (125 or 250 or 500 mg/kg/day) for 5 days before the induction of CI-AKI. Renal function and oxidative stress markers; malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD) and catalase (CAT) activity were determined in plasma and renal tissue. Kidney sections were performed for histopathological examination.

Results

In the contrast media (CM) group, increases in blood urea nitrogen and serum creatinine were demonstrated which correlated with severity of tubular necrosis, peritubular capillary congestion and interstitial edema. Moreover, an increase in MDA and a decrease in TAC SOD and CAT activity in CM group were significantly changed when compared with the control (P < 0.05). In contrast, CI-AKI-induced rats administrated with PE extract 250 and 500 mg/kg/day significantly preserved renal function and attenuated the severity of pathological damage (P < 0.05) as well as significantly lower MDA and higher TAC, SOD and CAT than the CM group (P < 0.05).

Conclusions

This study demonstrated the protective role of PE extract against CI-AKI.

Gallic acid functions as a TRPA1 antagonist with relevant antinociceptive and antiedematogenic effects in mice

The transient receptor potential ankyrin 1 (TRPA1) has been identified as a relevant target for the development of novel analgesics. Gallic acid (GA) is a polyphenolic compound commonly found in green tea and various berries and possesses a wide range of biological activities. The goal of this study was to identify GA as a TRPA1 antagonist and observe its antinociceptive effects in different pain models. First, we evaluated the ability of GA to affect cinnamaldehyde-induced calcium influx. Then, we observed the antinociceptive and antiedematogenic effects of GA (3-100 mg/kg) oral administration after the intraplantar (i.pl.) injection of TRPA1 agonists (allyl isothiocyanate, cinnamaldehyde, or hydrogen peroxide-H2O2) in either an inflammatory pain model (carrageenan i.pl. injection) or a neuropathic pain model (chronic constriction injury) in male Swiss mice (25-35 g). GA reduced the calcium influx mediated by TRPA1 activation. Moreover, the oral administration of GA decreased the spontaneous nociception triggered by allyl isothiocyanate, cinnamaldehyde, and H2O2. Carrageenan-induced allodynia and edema were largely reduced by the pretreatment with GA. Moreover, the administration of GA was also capable of decreasing cold and mechanical allodynia in a neuropathic pain model. Finally, GA was absorbed after oral administration and did not produce any detectable side effects. In conclusion, we found that GA is a TRPA1 antagonist with antinociceptive properties in relevant models of clinical pain without detectable side effects, which makes it a good candidate for the treatment of painful conditions.

Effect of fluorosis on liver cells of VC deficient and wild type mice

For decades, mouse and other rodents have been used for the study of oxidative or related studies such as the effect of fluoride. It is known that rodents normally synthesize their own vitamin C (VC) due to the presence of a key enzyme in ascorbic acid synthesis, l-gulono-lactone-γ-oxidase (Gulo), while humans do not have the capacity of VC synthesis due to the deletion of most parts of the GULO gene. The spontaneous fracture (sfx) mouse recently emerged as a model for study of VC deficiency. We investigated the effect of fluoride on liver cells from wild type Balb/c and sfx mice. We found that activities of SOD, GPx, and CAT were reduced in both wild type and sfx mice; however, the amount of reduction in the sfx cells is more than that in Balb/c cells. In addition, while both cells increased MDA, the increase in the sfx cells is greater than that in Balb/c cells. Gene networks of Sod, Gpx, and Cat in the liver of humans and mice are also different. Our study suggests that reaction to fluoride in vitamin C deficient mice might be different from that of wild type mice.

Ameliorative effects of oleanolic acid on fluoride induced metabolic and oxidative dysfunctions in rat brain: Experimental and biochemical studies

Beneficial effects of oleanolic acid on fluoride-induced oxidative stress and certain metabolic dysfunctions were studied in four regions of rat brain. Male Wistar rats were treated with sodium fluoride at a dose of 20 mg/kg b.w./day (orally) for 30 days. Results indicate marked reduction in acidic, basic and neutral protein contents due to fluoride toxicity in cerebrum, cerebellum, pons and medulla. DNA, RNA contents significantly decreased in those regions after fluoride exposure. Activities of proteolytic enzymes (such as cathepsin, trypsin and pronase) were inhibited by fluoride, whereas transaminase enzyme (GOT and GPT) activities increased significantly in brain tissue. Fluoride appreciably elevated brain malondialdehyde level, free amino acid nitrogen, NO content and free OH radical generation. Additionally, fluoride perturbed GSH content and markedly reduced SOD, GPx, GR and CAT activities in brain tissues. Oral supplementation of oleanolic acid (a plant triterpenoid), at a dose of 5mg/kgb.w./day for last 14 days of fluoride treatment appreciably ameliorated fluoride-induced alteration of brain metabolic functions. Appreciable counteractive effects of oleanolic acid against fluoride-induced changes in protein and nucleic acid contents, proteolytic enzyme activities and other oxidative stress parameters indicate that oleanolic acid has potential antioxidative effects against fluoride-induced oxidative brain damage.

Combined effects of fluoride and cadmium on liver and kidney function in male rats

It has been shown that cadmium and fluoride may both have adverse effects on liver and kidney functions, but most studies focus on a single agent. In this study, we observed the effects of cadmium and fluoride on liver and kidney functions using a rat model. Total of 24 Sprague-Dawley male rats were divided into four groups, one control group and three exposure groups that were given cadmium (50 mg/L) and fluoride (100 mg/L) alone or in combination via drinking water. At the 12th week, urine, blood, and kidney tissues were collected. Aspartate transaminase, alanine transaminase (ALT), urinary β2-microglobulin, and albumin were determined. Contents of malondialdehyde (MDA) and superoxide dismutase (SOD) in liver and kidney homogenates were measured to evaluate oxidative stress. There was a significant increase in serum ALT and urinary β2-microglobulin of rats in exposure groups compared with control. Serum ALT and urinary β2-microglobulin of rats exposed to cadmium and fluoride in combination was significantly higher than those treated with cadmium alone and fluoride alone. SOD declined significantly and MDA increased in combination group compared with control and those treated with cadmium and fluoride alone. Cadmium and fluoride co-exposure increase the liver and kidney damage compared with that exposed to cadmium or fluoride alone.

Antioxidant and anti-fatigue activities of phenolic extract from the seed coat of Euryale ferox Salisb. and identification of three phenolic compounds by LC-ESI-MS/MS

This study investigated the antioxidant potential and anti-fatigue effects of phenolics extracted from the seed coat of Euryale ferox Salisb. The in vitro antioxidant potentials, including scavenging DPPH, hydroxyl radical activities and reducing power were evaluated. Antioxidant status in vivo was analyzed by SOD, CAT, GSH-Px activities and the MDA content in liver and kidneys of D-galactose-induced aging mice. The anti-fatigue effect was evaluated using an exhaustive swimming test, along with the determination of LDH, BUN and HG content. The phenolic extract possessed notable antioxidant effects on DPPH, hydroxyl radical scavenging and reducing power. The mice which received the phenolic extract showed significant increases of SOD, CAT (except for in the kidney), GSH-Px activities, and a decrease of MDA content. The average exhaustive swimming time was obviously prolonged. Meanwhile, increase of LDH content and decrease of BUN content were observed after mice had been swimming for 15 min. The HG storage of mice was improved in the high and middle dose extract groups compared with the normal group. The contents of total phenols and gallic acid of the extract were determined. Three compounds in the extract were identified as 5,7-dihydroxy-2-(3,4,5-trihydroxyphenyl)-chroman-4-one, 5,7,4-trihydroxyflavanone and buddlenol E. These results suggest that the extract of E. ferox is a promising source of natural antioxidants and anti-fatigue material for use in functional foods and medicines.

Effects of acute sodium fluoride exposure on kidney function, water homeostasis, and renal handling of calcium and inorganic phosphate

Fluoride compounds are abundant and widely distributed in the environment at a variety of concentrations. Further, fluoride induces toxic effects in target organs such as the liver and kidney. In this study, we performed an early analysis of renal function using a clearance technique in Wistar rats acutely exposed to fluoride at a plasma concentration of 0.625 μg/ml. Our results revealed that fluoride, at a concentration close to the concentration present in the serum after environmental exposure, induced a significant tubular dysfunction, resulting in diluted urine, impaired protein reabsorption, and increased calcium and phosphate urinary excretion. Our work demonstrates that even acute exposures to low concentrations of NaF may induce renal damage and confirms that, after exposure, the kidney participates directly in the calcium and phosphate deficiencies observed in fluoride-exposed populations.

An investigation of the effect of thiamine pyrophosphate on cisplatin-induced oxidative stress and DNA damage in rat brain tissue compared with thiamine

This study investigated the effects of thiamine pyrophosphate (TPP) at dosages of 10 and 20 mg/kg on oxidative stress induced in rat brain tissue with cisplatin and compared this with thiamine. Cisplatin neurotoxicity represents one of the main restrictions on the drug being given in effective doses. Oxidative stress is considered responsible for cisplatin toxicity. Our results showed that cisplatin increased the levels of oxidant parameters such as lipid peroxidation (thio barbituric acid reactive substance (TBARS)) and myeloperoxidase (MPO) in brain tissue and suppressed the effects of antioxidants such as total glutathione (GSH) and superoxide dismutase (SOD). TPP, especially at a dosage of 20 mg/kg, significantly reduced TBARS and MPO levels that increase with cisplatin administration compared with the thiamine group, while TPP significantly increases GSH and SOD levels. In addition, the level of 8-Gua (guanine), a product of DNA damage, was 1.7 ± 0.12 8-hydroxyl guanine (8-OH Gua)/105 Gua in brain tissue in the control group receiving cisplatin, compared with 0.97 ± 0.03 8-OH Gua/105 Gua in the thiamine pyrophosphate (20 mg/kg) group and 1.55 ± 0.11 8-OH Gua/105 Gua in the thiamine (20 mg/kg) group. These results show that thiamine pyrophosphate significantly prevents oxidative damage induced by cisplatin in brain tissue, while the protective effect of thiamine is insignificant.

Neuroprotective effects of methyl-3-O-methyl gallate against sodium fluoride-induced oxidative stress in the brain of rats

Methyl-3-O-methyl gallate (M3OMG) is a rare natural product that showed promising in vitro antioxidant activities. In this study, the protective role of synthetic M3OMG against sodium fluoride (NaF)-induced oxidative stress in rat brain was evaluated. Animals were treated with either M3OMG (10 and 20 mg/kg i.p.), vitamin C (10 mg/kg i.p.) as the standard antioxidant or the vehicle (5 % dimethyl sulfoxide; 1 ml/kg) for 1 week. Oxidative stress was induced in the brain by adding 600 ppm NaF in the drinking water for 7 days. At the end of the treatment period, the levels of thiobarbituric acid reactive substances (TBARS), reduced glutathione and the activities of antioxidant enzymes (superoxide dismutase and catalase) were evaluated in brain homogenates. M3OMG treatment mitigated the NaF-induced oxidative stress through normalization of the level of TBARS, reduced levels of glutathione and by the restoration of the diminished antioxidant enzyme activities. In conclusion, M3OMG could have a potential for treating neurotoxicity induced by fluoride or related environmental pollutants.