Comparative Pharmacokinetics of Gallic Acid After Oral Administration of Gallic Acid Monohydrate in Normal and Isoproterenol-Induced Myocardial Infarcted Rats

Gallic acid: a dietary metabolite's therapeutic potential in the management of atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease (ASCVD) causes significant morbidity and mortality globally. Most of the chemicals specifically target certain pathways and minimally impact other diseases associated with ASCVD. Moreover, interactions of these drugs can cause toxic reactions. Consequently, the exploration of multi-targeted and safe medications for treating and preventing ASCVD has become an increasingly popular trend. Gallic acid (GA), a natural secondary metabolite found in various fruits, plants, and nuts, has demonstrated potentials in preventing and treating ASCVD, in addition to its known antioxidant and anti-inflammatory effects. It alleviates the entire process of atherosclerosis (AS) by reducing oxidative stress, improving endothelial dysfunction, and inhibiting platelet activation and aggregation. Additionally, GA can treat ASCVD-related diseases, such as coronary heart disease (CHD) and cerebral ischemia. However, the pharmacological actions of GA in the prevention and treatment of ASCVD have not been comprehensively reviewed, which limits its clinical development. This review primarily summarizes the in vitro and in vivo pharmacological actions of GA on the related risk factors of ASCVD, AS, and ASCVD. Additionally, it provides a comprehensive overview of the toxicity, extraction, synthesis, pharmacokinetics, and pharmaceutics of GA,aimed to enhance understanding of its clinical applications and further research and development.

Pharmacokinetic-Pharmacodynamic Correlation Analysis of Rhodiola crenulata in Rats with Myocardial Ischemia

The pharmacokinetics (PK) of Rhodiola crenulata in rats were studied, and pharmacokinetic-pharmacodynamic (PK-PD) correlation analysis was performed to elucidate their time-concentration-effect relationship. The myocardial ischemia model was made with pituitrin. Rats were divided into sham operation, sham operation administration, model, and model administration groups (SG, SDG, MG, and MDG, respectively; n = 6). Blood was collected from the fundus venous plexus at different time points after oral administration. The HPLC-QQQ-MS/MS method was established for the quantification of five components of Rhodiola crenulata. CK, HBDH, SOD, LDH, and AST at different time points were detected via an automatic biochemical analyzer. DAS software was used to analyze PK parameters and PK-PD correlation. The myocardial ischemia model was established successfully. There were significant differences in the PK parameters (AUC0-t, AUC0-∞, Cmax) in MDG when compared with SDG. Two PD indicators, CK and HBDH, conforming to the sigmoid-Emax model, had high correlation with the five components, which indicated a delay in the pharmacological effect relative to the drug concentration in plasma. The difference in the PK parameters between modeled and normal rats was studied, and the time-concentration-effect of composition and effect indicators were investigated. This study can provide reference for the rational clinical application of Rhodiola crenulata and for related studies of other anti-myocardial ischemia drugs.

Polyethyleneimine in designed nanocomposite based magnetic halloysite nanotubes for extraction and determination of gallic acid in green tea

An innovative and simple nanocomposite denoted as MHNTs@PEI was synthesized for gallic acid (GA) analytical sample pretreatment. Polyethyleneimine (PEI) functionalized was binded onto magnetic halloysite nanotubes (MHNTs) to inhence adsorption capacity. MHNTs@PEI was obtained only through two steps modification (amination and PEI modification). Characterizations showed that there are layers of synthetic PEI on the tubular structure of the material and magnetic spheres on its surface, both indicating successful synthesis of the nanocomposite. Furthermore, the adsorption isotherms and kinetic modeling showed that the Langmuir model and pseudo-first-order model fit the adsorption data, respectively. MHNTs@PEI achieved an adsorption capacity of 158 mg·g-1. Overall, the abundant adsorption sites significantly improved the adsorption performance of the MHNTs@PEI. Regeneration tests demonstrated that the MHNTs@PEI exhibits effective adsorption, even after undergoing five consecutive cycles. Optimization of key parameters (ratio, volume of elution, elution time and frequency) in the process of adsorption and desorption was also conducted. The limit of detection (LOD) and that of the quantification (LOQ) were 0.19 and 0.63 μg·mL-1, respectively, and the recoveries were 95.67-99.43 %. Finally, the excellent magnetism (43.5 emu·g-1) and the adsorption feature of MHNTs@PEI enabled its successful utilization in analytical sample pretreatment through the extraction of GA from green tea.

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

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

Multifunctional gallic acid self-assembled hydrogel for alleviation of ethanol-induced acute gastric injury

Ethanol-induced acute gastric injury is a prevalent type of digestive tract ulcer, yet conventional treatments strategies frequently encounter several limitations, such as poor bioavailability, degradation of enzymes and adverse side effects. Gallic acid (GA), a natural compound extracted from dogwood, has demonstrated potential protective effects in mitigating acute gastric injury. However, its poor stability and limited bioavailability have restricted applications in vivo. To address these issues, we report a hydrogel constructed only by gallic acid with high bioavailability for alleviation of gastric injury. Molecular dynamic simulation studies revealed that the self-assembly of GA into hydrogel was predominantly attributed to π-π and hydrogen bonds. After assembling, the GA hydrogel exhibits superior anti-oxidative stress, anti-apoptosis and anti-inflammatory properties compared with free GA. As anticipated, in vitro experiments demonstrated that GA hydrogel possessed the remarkable ability to promote the proliferation of GES-1 cells, and alleviates apoptosis and inflammation caused by ethanol. Subsequent in vivo investigation further confirmed that GA hydrogel significantly alleviated ethanol-triggered acute gastric injury. Mechanistically, GA hydrogel treatment enhanced the antioxidant capacity, reduced oxidative stress while simultaneously suppressing the secretion of pro-inflammatory cytokines and reduced the production of pro-apoptotic proteins during the process of gastric injury. Our finding suggest that this multifunctional GA hydrogel is a promising candidate for gastric injury, particularly in cases of ethanol-induced acute gastric injury.

Neurobiological effects of gallic acid: current perspectives

Gallic acid (GA) is a phenolic molecule found naturally in a wide range of fruits as well as in medicinal plants. It has many health benefits due to its antioxidant properties. This study focused on finding out the neurobiological effects and mechanisms of GA using published data from reputed databases. For this, data were collected from various sources, such as PubMed/Medline, Science Direct, Scopus, Google Scholar, SpringerLink, and Web of Science. The findings suggest that GA can be used to manage several neurological diseases and disorders, such as Alzheimer's disease, Parkinson's disease, strokes, sedation, depression, psychosis, neuropathic pain, anxiety, and memory loss, as well as neuroinflammation. According to database reports and this current literature-based study, GA may be considered one of the potential lead compounds to treat neurological diseases and disorders. More preclinical and clinical studies are required to establish GA as a neuroprotective drug.

Phenolic Secondary Metabolites and Antiradical and Antibacterial Activities of Different Extracts of Usnea barbata (L.) Weber ex F.H.Wigg from Călimani Mountains, Romania

Phenolic compounds represent an essential bioactive metabolites group with numerous pharmaceutical applications. Our study aims to identify and quantify phenolic constituents of various liquid and dry extracts of Usnea barbata (L.) Weber ex F.H. Wigg (U. barbata) from Calimani Mountains, Romania, and investigate their bioactivities. The extracts in acetone, 96% ethanol, and water with the same dried lichen/solvent ratio (w/v) were obtained through two conventional techniques: maceration (mUBA, mUBE, and mUBW) and Soxhlet extraction (dUBA, dUBE, and dUBW). High-performance liquid chromatography with diode-array detection (HPLC-DAD) was performed for usnic acid (UA) and different polyphenols quantification. Then, the total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging activity (AA) were determined through spectrophotometric methods. Using the disc diffusion method (DDM), the antibacterial activity was evaluated against Gram-positive and Gram-negative bacteria known for their pathogenicity: Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella pneumoniae (ATCC 13883). All extracts contain phenolic compounds expressed as TPC values. Five lichen extracts display various UA contents; this significant metabolite was not detected in dUBW. Six polyphenols from the standards mixture were quantified only in ethanol and water extracts; mUBE has all individual polyphenols, while dUBE shows only two. Three polyphenols were detected in mUBW, but none was found in dUBW. All U. barbata extracts had antiradical activity; however, only ethanol and acetone extracts proved inhibitory activity against P. aeruginosa, S. pneumoniae, and S. aureus. In contrast, K. pneumoniae was strongly resistant (IZD = 0). Data analysis evidenced a high positive correlation between the phenolic constituents and bioactivities of each U. barbata extract. Associating these extracts’ properties with both conventional techniques used for their preparation revealed the extraction conditions’ significant influence on lichen extracts metabolites profiling, with a powerful impact on their pharmacological potential.

Low-Dose Gallic Acid Administration Does Not Improve Diet-Induced Metabolic Disorders and Atherosclerosis in Apoe Knockout Mice

Diets rich in polyphenols are known to be beneficial for cardiovascular health. Gallic acid (GA) is a plant-derived triphenolic chemical with multiple cardio-protective properties, such as antiobesity, anti-inflammation, and antioxidation. However, whether GA could protect against atherosclerotic cardiovascular diseases is still not defined. Here, we investigated the effects of low-dose GA administration on diet-induced metabolic disorders and atherosclerosis in the atherosclerosis-prone apolipoprotein E (Apoe) knockout mice fed on a high-fat Western-type diet (WTD) for 8 weeks. Our data showed that GA administration by oral gavage at a daily dosage of 20 mg/kg body weight did not significantly ameliorate WTD-induced hyperlipidemia, hepatosteatosis, adipogenesis, or insulin resistance; furthermore, GA administration did not significantly ameliorate WTD-induced atherosclerosis. In conclusion, our data demonstrate that low-dose GA administration does not elicit significant health effect on diet-induced metabolic disorders or atherosclerosis in the Apoe knockout mice. Whether GA could be beneficial for atherosclerotic cardiovascular diseases therefore needs further exploration.

Gallic acid: a dietary polyphenol that exhibits anti-neoplastic activities by modulating multiple oncogenic targets

Phytochemicals are being used for thousands of years to prevent dreadful malignancy. Side effects of existing allopathic treatment have also initiated intense research in the field of bioactive phytochemicals. Gallic acid, a natural polyphenolic compound, exists freely as well as in polymeric forms. The anti-cancer properties of gallic acid are indomitable by a variety of cellular pathways such as induction of programmed cell death, cell cycle apprehension, reticence of vasculature and tumor migration, and inflammation. Furthermore, gallic acid is found to show synergism with other existing chemotherapeutic drugs. Therefore, the antineoplastic role of gallic acid suggests its promising therapeutic candidature in the near future. The present review describes all these aspects of gallic acid at a single platform. In addition nanotechnology-mediated approaches are also discussed to enhance bioavailability and therapeutic efficacy.

3,4,5-Trihydroxybenzoic Acid Attenuates Ligature-Induced Periodontal Disease in Wistar Rats

BACKGROUND

3,4,5-Trihydroxybenzoic acid, which is also known as gallic acid, is an antiinflammatory agent that could provide beneficial effects in preventing periodontal inflammation. The present study aimed to evaluate the anti-inflammatory effects of gallic acid on experimental periodontitis in Wistar rats. Alveolar bone loss, osteoclastic activity, osteoblastic activity, and collagenase activity were also determined.

METHODS

Thirty-two Wistar rats were used in the present study. Study groups were created as following: Healthy control (C,n=8) group; periodontitis (P,n=8) group; periodontitis and 30 mg/kg gallic acid administered group (G30,n=8); periodontitis and 60 mg/kg gallic acid administered group (G60,n=8). Experimental periodontitis was created by placing 4-0 silk sutures around the mandibular right first molar tooth. Morphological changes in alveolar bone were determined by stereomicroscopic evaluation. Mandibles were undergone histological evaluation. Matrix metalloproteinase (MMP)-8, tissue inhibitor of MMPs (TIMP)-1, bone morphogenetic protein (BMP)-2 expressions, tartrateresistant acid phosphatase (TRAP) positive osteoclast cells, osteoblast, and inflammatory cell counts were determined.

RESULTS

The highest alveolar bone loss was observed in the periodontitis group. Both doses of gallic acid decreased alveolar bone loss as compared to the P group. TRAP-positive osteoclast cell counts were higher in the P group, and gallic acid successfully lowered these counts. Osteoblast cells also increased in gallic acid administered groups. Inflammation in the P group was also higher than those of C, G30, and G60 groups supporting the role of gallic acid in preventing inflammation. 30 and 60 mg/kg doses of gallic acid decreased MMP-8 levels and increased TIMP-1 levels. BMP levels increased in gallic acid administered groups, similar to several osteoblasts.

CONCLUSION

Present results revealed an anti-inflammatory effect of gallic acid, which was indicated by decreased alveolar bone loss and collagenase activity and increased osteoblastic activity.

Gallic Acid Protects from Acute Multiorgan Injury Induced by Lipopolysaccharide and D-galactosamine

BACKGROUND

Secondary metabolites of plants, the polyphenols, play a vital role in protection from many health problems in human beings. Structurally favored phytochemicals may be studied to protect multiorgan injury. At pharmacological doses, gallic acid is nontoxic to mammals and is generally absorbed in the intestine.

AIMS

In this present study, gallic acid was evaluated for its protective efficacy against Lipo Polysaccharide (LPS) and d-Galactosamine (D-GalN) induced multiorgan injury, i.e., liver, kidney and brain.

METHODS

Three different doses of gallic acid (5, 10 and 20 mg/kg p.o.) were administered to the experimental animals for 6 consecutive days, followed by exposure to LPS (50 μg/kg I.P.) and D-GalN (300 mg/kg I.P.) on the 6th day.

RESULTS

Exposure to LPS and D-GalN resulted in increased oxidative stress and proinflammatory cytokines. Altered hematology and serology due to LPS and D-GalN were restored towards control by gallic acid. Declined antioxidants such as reduced glutathione, superoxide dismutase and catalase due to injurious effects of LPS and D-GalN were rejuvenated by gallic acid.

DISCUSSION

Exposure to LPS and D-GalN severely increased lipid peroxidation, CYP2E1 activity and tissue lipids while lowered protein content. Gallic acid restored all these parameters towards control in dose dependent manner and 20 mg/kg dose provided the best protection. Histological study showed improved histoarchitecture of liver, kidney and brain that supported biochemical endpoints.

CONCLUSION

Gallic acid minimized oxidative stress and provided best protection at 20 mg/kg dose against LPS and D-GalN induced multi organ acute injury.

Evaluation of the protective effects of quercetin and gallic acid against oxidative toxicity in rat's kidney and HEK-293 cells

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Gallic acid has better antioxidant protective effect than quercetin in vivo.

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Quercetin has better antioxidant protective effect than gallic acid in vitro.

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The antioxidant effect of quercetin was at the least concentration tested.

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The antioxidant effect of gallic acid was at a higher concentrated tested.

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The in vivo dosage for the antioxidant effects of quercetin in the kidney is low.

Quercetin and gallic acid are phytochemicals with interesting pharmacological properties. We herein investigated the protective effect of quercetin (QUE) in comparison with gallic acid (GAL) against exogenously-induced oxidative damage in rats’ kidney and human embryonic kidney (HEK-293) cell lines. Adult Wistar rats were treated with QUE and GAL (50 mg/kg) separately or in combination with di-n-butylphthalate (DnBP) for 14 days; and HEK-293 cells were treated with different concentrations of GAL (25−294 μM) or QUE (2−17 μM or 28−165.43 μM) singly or in combination with H₂O₂ (200 μM). After treatment, the kidney and cell extracts were processed for biochemical analysis and histopathology. We found that GAL but not QUE prevented DnBP-induced increase in lipid peroxidation (2.603 ± 0.25 vs. 3.65 ± 0.21 μmol/mL). Treatment with QUE but not GAL was associated with increased plasma creatinine (729.09 ± 55.68 vs. 344.25 ± 50.78 μmol/l) and tissue malondialdehyde (3.72 ± 0.62 vs. 1.67 ± 0.47 μmol/mL) concentrations, along with histo-pathological changes such as glomerular and tubular degenerations. However, QUE exhibited wider therapeutic concentration ranges than GAL at which it inhibits lipid peroxidation in HEK-293 cells, and was found to inhibit H₂O₂-induced lipid peroxidation even at the lowest concentration (2 μM) that was tested (0.607 ± 0.074 vs. 0.927 ± 0.106 μmol/l). These suggest that the in vivo dosages required for the antioxidant protective effects of QUE in renal tissues are low.

Phenolic Acids of Plant Origin-A Review on Their Antioxidant Activity In Vitro (O/W Emulsion Systems) Along with Their in Vivo Health Biochemical Properties

Nature has generously offered a wide range of herbs (e.g., thyme, oregano, rosemary, sage, mint, basil) rich in many polyphenols and other phenolic compounds with strong antioxidant and biochemical properties. This paper focuses on several natural occurring phenolic acids (caffeic, carnosic, ferulic, gallic, p-coumaric, rosmarinic, vanillic) and first gives an overview of their most common natural plant sources. A summary of the recently reported antioxidant activities of the phenolic acids in o/w emulsions is also provided as an in vitro lipid-based model system. Exploring the interfacial activity of phenolic acids could help to further elucidate their potential health properties against oxidative stress conditions of biological membranes (such as lipoproteins). Finally, this review reports on the latest literature evidence concerning specific biochemical properties of the examined phenolic acids.

Characterising absorption and health-related properties of phytochemicals extracted from Malaysian palm fruit biomass after oil extraction

After oil extraction, palm fruit biomass contains abundant water-soluble phytochemicals (PCs) with proven bioactivity in regulating oxidative stress and inflammation (OSI).

Hydroalcoholic Extract from Rhizomes of Cynodon dactylon Improve Hemodynamic and Electrocardiogram Parameters in Myocardial Infarction in Rats

Background: Cynodon dactylon is a herbal medicine of interest in Iranian traditional medicine, which is used in cardiovascular diseases such as atherosclerosis and heart failure. The purpose of this study was to evaluate the effects of total extract of C. dactylon rhizomes on myocardial infarction and on post myocardial infarction (MI) heart tissue injuries. Methods: Isoproterenol (100 mg/kg) was injected subcutaneously for two consecutive days for induction of MI in rats and C. dactylon extract was administered orally twice daily started before isoproterenol injection for 4 consecutive days. Results: Histopathological analysis showed a marked increase in myocardial necrosis in rats with MI (p<0.001). Treatment with C. dactylon (200 mg/kg) significantly (P<0.05) decreased myocardial necrosis. Hemodynamic variables were significantly suppressed in MI group and treatment with C. dactylon improved the hemodynamic parameters (P<0.05). Our electrocardiogram analysis demonstrated that C. dactylon with all doses increased R-Amplitude and R-R Interval (p<0.05, p<0.01) which were suppressed in MI group. Furthermore in treated groups with 100 and 200 mg/kg, P-R interval was also significantly increased in compared to MI group. Conclusion: This study demonstrated that C. dactylon can improve hemodynamic and electrocardiogram parameters in isoproterenol-induced myocardial infarction and thereby suggest that it can be used as a cardioprotective agent in myocardial infarction.

Targeting Antioxidants to Interfaces: Control of the Oxidative Stability of Lipid-Based Emulsions

The oxidation of lipid-based emulsions and nanoemulsions strongly affects their overall quality and safety. Moreover, introduction of oxidatively unstable emulsions into biological systems either as an energy source in parenteral nutrition or as delivery systems of bioactives may promote oxidation "in situ" leading to the overproduction of reactive oxygen species, initiating new harmful oxidative reactions and increasing the oxidative damage. Addition of antioxidants, AOs, may help to prevent the oxidative degradation of unsaturated lipids. Nevertheless, prediction of the optimal antioxidant or set of antioxidants and their efficiency is still far from being completely understood because the site of reaction is often uncertain and because the effective concentrations of reactants in the different regions of the emulsion have been frequently overlooked. Furthermore, the absence of quantitative relationships between the hydrophobicity of the antioxidants and their partitioning among the oil, water, and interfacial regions hampers their optimal use. Here we investigated the effects of gallic acid and some of its alkyl derivatives on the oxidative stability of soybean oil-in-water emulsions and determined their effective concentrations in the different regions of the emulsion (aqueous, oil, and interface). The results provide physical evidence for the crucial role played by the interfacial region in the reaction between antioxidants and lipid radicals: a direct relationship between interfacial concentrations and the oxidative stability could be established. The results indicate that AOs accumulate in the interfacial region, where the effective concentration is 20-180 times higher than the stoichiometric concentrations. Control of the hydrophobicity of the AOs and of the surfactant concentration allows control of interfacial concentrations: the lower the concentration of surfactant employed, the higher the effective interfacial concentration.

Inflammation and Oxidative Stress in an Obese State and the Protective Effects of Gallic Acid

Metabolic complications in an obese state can be aggravated by an abnormal inflammatory response and enhanced production of reactive oxygen species. Pro-inflammatory response is known to be associated with the formation of toxic reactive oxygen species and subsequent generation of oxidative stress. Indeed, adipocytes from obese individuals display an altered adipokine profile, with upregulated expression and secretion of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin (IL-6). Interestingly, natural compounds, including phenolic enriched foods are increasingly explored for their ameliorative effects against various metabolic diseases. Of interest is gallic acid, a trihydroxybenzoic acid that has progressively demonstrated robust anti-obesity capabilities in various experimental models. In addition to reducing excessive lipid storage in obese subjects, gallic acid has been shown to specifically target the adipose tissue to suppress lipogenesis, improve insulin signaling, and concomitantly combat raised pro-inflammatory response and oxidative stress. This review will revise mechanisms involved in the pathophysiological effects of inflammation and oxidative stress in an obese state. To better inform on its therapeutic potential and improvement of human health, available evidence reporting on the anti-obesity properties of gallic acid and its derivatives will be discussed, with emphases on its modulatory effect on molecular mechanisms involved in insulin signaling, inflammation and oxidative stress.

The antioxidant gallic acid induces anxiolytic-, but not antidepressant-like effect, in streptozotocin-induced diabetes

The physiopathology of anxiety or depression related to diabetes is still poorly understood. The treatment with antidepressant drugs is a huge challenge due to theirs adherence low rate and many adverse effects. Thus, the seeking for a better treatment for these associated diseases is of utmost importance. Given that the oxidative stress in different tissues occurs in diabetes and anxiety or depression as well, the antioxidant gallic acid becomes an interesting compound to be investigated. Thus, the effects of long-term treatment with gallic acid (0, 10, 20 and 40 mg/kg; gavage) were evaluated in diabetic (DBT) animals submitted to the elevated plus-maze (EPM), the light-dark transition (LDT) tests and modified forced swim test (mFST). Also, indirect parameters of oxidative stress, lipid peroxidation (LPO) and reduced glutathione (GSH) levels were evaluated in the hippocampus (HIP) and prefrontal cortex (PFC). The results showed that DBT animals presented a decrease in the spent time in the open arms, in the end arm exploration and head dips when evaluated in the EPM test; moreover, a decrease in the spent time in the lit compartment of LDT test was observed, suggesting an anxiogenic-like behavior. During the mFST, an increase in the mean counts of immobility and a decrease in the mean counts of swimming and climbing were observed, indicating a depressive-like behavior. These aversive behaviors were more pronounced when compared to normoglycemic (NGL) animals and streptozotocin-treated animals that not become DBT. In addition, DBT rats showed an increase in the oxidative stress parameters in the HIP and PFC that was reversed by the gallic acid treatment (lowest dose - 10 mg/kg), i.e., the treatment decreased the elevated LPO levels and increased the reduced GSH in the HIP and PFC. Also, gallic acid treatment was able to produce an anxiolytic-like effect in the EPM and LDT tests, but not antidepressant-like effect in the FST. Taken together, the results suggest that the antioxidant/neuroprotective effect of gallic acid treatment in HIP and PFC of DBT animals may be essential to the anxiolytic-like effect.