Gallic Acid Inhibits Lipid Accumulation via AMPK Pathway and Suppresses Apoptosis and Macrophage-Mediated Inflammation in Hepatocytes

Photothermal switch by gallic acid-calcium grafts synthesized by coordination chemistry for sequential treatment of bone tumor and regeneration

The residual bone tumor and defects which is caused by surgical therapy of bone tumor is a major and important problem in clinicals. And the sequential treatment for irradiating residual tumor and repairing bone defects has wildly prospects. In this study, we developed a general modification strategy by gallic acid (GA)-assisted coordination chemistry to prepare black calcium-based materials, which combines the sequential photothermal therapy of bone tumor and bone defects. The GA modification endows the materials remarkable photothermal properties. Under the near-infrared (NIR) irradiation with different power densities, the black GA-modified bone matrix (GBM) did not merely display an excellent performance in eliminating bone tumor with high temperature, but showed a facile effect of the mild-heat stimulation to accelerate bone regeneration. GBM can efficiently regulate the microenvironments of bone regeneration in a spatial-temporal manner, including inflammation/immune response, vascularization and osteogenic differentiation. Meanwhile, the integrin/PI3K/Akt signaling pathway of bone marrow mesenchymal stem cells (BMSCs) was revealed to be involved in the effect of osteogenesis induced by the mild-heat stimulation. The outcome of this study not only provides a serial of new multifunctional biomaterials, but also demonstrates a general strategy for designing novel blacked calcium-based biomaterials with great potential for clinical use.

Transcriptome analysis reveals high concentration of resveratrol promotes lipid synthesis and induces apoptosis in Siberian sturgeon (Acipenser baerii)

Resveratrol has been reported to promote immunity and decrease oxidative stress, but which demonstrates biphasic effects relied on the use concentration. In this study, the effects of diet supplement with a relative high concentration of resveratrol (0.32 mg/kg) on metabolism, antioxidation and apoptosis of liver were investigated in Siberian sturgeon. The results showed that resveratrol significantly increased the lipid synthesis and the apoptosis, but did not either activate the antioxidant NRF2/KEAP1 pathway or enhance the antioxidant enzyme activity. Transcriptome analysis revealed significant changes in regulatory pathways related to glycolipid, including PPAR signaling pathway, Insulin signaling pathway, Fatty acid biosynthesis, and Glycolysis/Gluconeogenesis. In addition, resveratrol significantly increased the lipid synthesis genes (accα and fas), fatty acid transport gene (fatp 6) and gluconeogenesis gene (gck), but decreased the survival-promoting genes (gadd45β and igf 1). These findings highlight a significant effect of resveratrol on glycolipid metabolism in Siberian sturgeon. Moreover, this study also demonstrated that 0.32 mg/kg resveratrol has physiological toxicity to the liver of Siberian sturgeon, indicating that this dose is too high for Siberian sturgeon. Thus, our study provides a valuable insight for future research and application of resveratrol in fish.

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.

Gallic Acid Attenuates Sepsis-Induced Liver Injury through C/EBPβ-Dependent MAPK Signaling Pathway

SCOPE

Liver injury is a major complication associated with sepsis. Together with others, the study has shown that gallic acid (GA) exerts anti-inflammatory and antioxidant effects in vivo. However, the role of GA in sepsis-mediated hepatic impairment and the underlying mechanisms remains to be elucidated.

METHODS AND RESULTS

C57BL/6J mice are pretreated with saline or GA and subjected to sham or cecal ligation and puncture (CLP). The pathological alterations are assessed by hematoxylin and eosin staining as well as immunohistochemical staining. RNA sequencing is employed to analyze hepatic transcriptome modifications. The study finds that GA supplementation significantly ameliorates CLP-induced mortality, liver dysfunction, and inflammation. RNA sequencing reveals that 1324 genes are markedly differentially regulated in livers of saline- or GA-treated sham or CLP mice. Gene ontology analysis demonstrates that the differentially expressed genes regulated by GA are predominantly correlated with the immune system process, oxidation-reduction process, and inflammatory response. Furthermore, mitogen-activated protein kinase (MAPK) signaling is localized in the center of the GA-mediated pathway network. Notably, activation of MAPK by C16-PAF significantly blocks GA-mediated protective effects on hepatic injury, inflammation, as well as CCAAT/enhancer-binding protein-β (C/EBPβ) dependent extracellular signal-regulated kinase 1/2 (ERK1/2) and nuclear factor-κB (NF-κB) signaling.

CONCLUSION

Therefore, this study indicates that GA may offer a promising therapeutic opportunity for sepsis-associated liver injury.

Dietary gallic acid as an antioxidant: A review of its food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions

Gallic acid (GA), a dietary phenolic acid with potent antioxidant activity, is widely distributed in edible plants. GA has been applied in the food industry as an antimicrobial agent, food fresh-keeping agent, oil stabilizer, active food wrap material, and food processing stabilizer. GA is a potential dietary supplement due to its health benefits on various functional disorders associated with oxidative stress, including renal, neurological, hepatic, pulmonary, reproductive, and cardiovascular diseases. GA is rapidly absorbed and metabolized after oral administration, resulting in low bioavailability, which is susceptible to various factors, such as intestinal microbiota, transporters, and metabolism of galloyl derivatives. GA exhibits a tendency to distribute primarily to the kidney, liver, heart, and brain. A total of 37 metabolites of GA has been identified, and decarboxylation and dihydroxylation in phase I metabolism and sulfation, glucuronidation, and methylation in phase Ⅱ metabolism are considered the main in vivo biotransformation pathways of GA. Different types of nanocarriers, such as polymeric nanoparticles, dendrimers, and nanodots, have been successfully developed to enhance the health-promoting function of GA by increasing bioavailability. GA may induce drug interactions with conventional drugs, such as hydroxyurea, linagliptin, and diltiazem, due to its inhibitory effects on metabolic enzymes, including cytochrome P450 3A4 and 2D6, and transporters, including P-glycoprotein, breast cancer resistance protein, and organic anion-transporting polypeptide 1B3. In conclusion, in-depth studies of GA on food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions have laid the foundation for its comprehensive application as a food additive and dietary supplement.

The role of fat-soluble vitamins in efferocytosis

Cell death and the efficient removal of dead cells are two basic mechanisms that maintain homeostasis in multicellular organisms. efferocytosis, which includes four steps recruitment, recognition, binding and signaling, and engulfment. Effectively and quickly removes apoptotic cells from the body. Any alteration in efferocytosis can lead to several diseases, including autoimmune and inflammatory conditions, atherosclerosis, and cancer. A wide range of dietary components affects apoptosis and, subsequently, efferocytosis. Some vitamins, including fat-soluble vitamins, affect different stages of efferocytosis. Among other things, by affecting macrophages, they are effective in the apoptotic cleansing of cells. Also, polyphenols indirectly intervene in efferocytosis through their effect on apoptosis. Considering that there are limited articles on the effect of nutrition on efferocytosis, in this article we will examine the effect of some dietary components on efferocytosis.

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.

Eugeniin improves cholesterol metabolism in HepG2 cells and Caco-2 cells

Considering the absence of prior studies on the cholesterol metabolism-improving effects of eugeniin, the present investigation aimed to explore the potential impact of eugeniin on cholesterol metabolism. This study sought to elucidate the molecular mechanisms involved in this process using HepG2 and Caco-2 cells treated with 5 µm eugeniin. The intracellular cholesterol levels in HepG2 and Caco-2 cells were significantly decreased in the 24-h eugeniin-treated group. The protein and messenger ribonucleic acid (mRNA) levels of the low-density lipoprotein receptor (LDLR) were increased, while 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase protein and mRNA levels were decreased in HepG2 cells 6 h of the eugeniin-treated group. Additionally, LDLR protein and mRNA levels were increased in HepG2 cells after 24 h of eugeniin treatment. In Caco-2, the protein and mRNA levels of ATP-binding cassette transporter 1 were increased after 24 h eugeniin treatment. This novel finding indicates that eugeniin improves cholesterol metabolism in human cell cultures.

The role of AMPK in macrophage metabolism, function and polarisation

AMP-activated protein kinase (AMPK) is a ubiquitous sensor of energy and nutritional status in eukaryotic cells. It plays a key role in regulating cellular energy homeostasis and multiple aspects of cell metabolism. During macrophage polarisation, AMPK not only guides the metabolic programming of macrophages, but also counter-regulates the inflammatory function of macrophages and promotes their polarisation toward the anti-inflammatory phenotype. AMPK is located at the intersection of macrophage metabolism and inflammation. The metabolic characteristics of macrophages are closely related to immune-related diseases, infectious diseases, cancer progression and immunotherapy. This review discusses the structure of AMPK and its role in the metabolism, function and polarisation of macrophages. In addition, it summarises the important role of the AMPK pathway and AMPK activators in the development of macrophage-related diseases.

Hibiscus Anthocyanins Extracts Induce Apoptosis by Activating AMP-Activated Protein Kinase in Human Colorectal Cancer Cells

Apoptosis, a programmed cell death process preventing cancer development, can be evaded by cancer cells. AMP-activated protein kinase (AMPK) regulates energy levels and is a key research topic in cancer prevention and treatment. Some bioactive components of Hibiscus sabdariffa L. (HAs), including anthocyanins, have potential anticancer properties. Our study investigated the in vitro cytotoxic potential and mode of action of HAs extracts containing anthocyanins in colorectal cancer cells. The results showed that Hibiscus anthocyanin-rich extracts induced apoptosis in human colorectal cancer cells through the activation of multiple signaling pathways of AMPK. We observed the dose-response and time-dependent induction of apoptosis with HAs. Subsequently, the activation of Fas-mediated proteins triggered apoptotic pathways associated with Fas-mediated apoptosis-related proteins, including caspase-8/tBid. This caused the release of cytochrome C from the mitochondria, resulting in caspase-3 cleavage and apoptosis activation in intestinal cancer cells. These data elucidate the relationship between Has' regulation of apoptosis-related proteins in colorectal cancer cells and apoptotic pathways.

AMPK negatively regulates RANKL-induced osteoclast differentiation by controlling oxidative stress

AMP-activated protein kinase (AMPK) is a crucial energy sensor of cellular metabolism under various metabolic stresses, such as oxidative stress and inflammation. AMPK deficiency increases osteoclast numbers and reduces bone mass; however, the precise mechanisms remain unclear. This study aimed to clarify the mechanistic connection between AMPK and osteoclast differentiation, and the potential role of AMPK in the anti-resorptive effects of several phytochemicals. We found that receptor activator of nuclear factor-kappa B (NF-κB) ligand (RANKL)-induced osteoclast differentiation, osteoclastic gene expression, and activation of mitogen-activated protein kinase (MAPK) and NF-κB were promoted in cells transfected with AMPK siRNA. AMPK knockdown led to defective synthesis of heme oxygenase-1, an antioxidant enzyme, and the upstream mediator, nuclear factor erythroid-2-related factor 2. Furthermore, treatment with N-acetyl-l-cysteine, an antioxidant, abolished osteoclast differentiation and MAPK/NF-κB activation induced by AMPK knockdown. AMPK activators, hesperetin, gallic acid, resveratrol, and curcumin, suppressed osteoclast differentiation via the activation of AMPK. These results suggest that AMPK inhibits RANKL-induced osteoclast differentiation by enhancing antioxidant defense system and regulating oxidative stress. AMPK activation by dietary-derived phytochemicals may be effective for the treatment of bone diseases.

Gallic acid and metformin co-administration reduce oxidative stress, apoptosis and inflammation via Fas/caspase-3 and NF-κB signaling pathways in thioacetamide-induced acute hepatic encephalopathy in rats

BACKGROUND

Hepatic encephalopathy (HE) is a consequence of chronic or acute liver diseases. This study evaluates the combined effect of gallic acid (GA), and metformin (Met) on the liver and brain damage associated with HE.

METHODS

Acute HE was induced by a single dose of thioacetamide (TAA) (300 mg/kg) as an I.P. injection. Treated groups received GA group (100 mg/kg/day, p.o), Met (200 mg/kg/day, p.o), or their combination for 25 consecutive days before TAA injection.

RESULTS

The administration of TAA induced various biochemical and histopathological alterations. In contrast, treatment with GA either alone or combined with Met resulted in improved liver functions by the significant reduction in serum ALT, AST, and ALP activities, and ammonia levels. Inflammatory mediators; TNF-α, IL-6, and NFkβ levels were decreased by these treatments as well as apoptotic cascade via down-regulation of FAS and caspase-3 (CASP-3) expression in hepatic tissues. Furthermore, GA and Met either alone or combined protected the liver and brain tissues from damage by increased glutathione concentration while decreasing malondialdehyde. In addition, it was accompanied by the improvement of the brain neurotransmitter profile via the restoration of norepinephrine, dopamine, and serotonin levels. Based on our data, this is the first study to report a novel combined hepatoprotective and cognitive enhancing effect of GA and Met against TAA-induced acute liver and brain injury.

CONCLUSION

GA and Met combination resulted in a prominent improvement in HE complications, relative to monotherapy. Both agents potentiated the antioxidant, anti-inflammatory, and anti-apoptotic effects of each other.

Effects of polyphenols and their metabolites on age-related diseases

Aging contributes to the progressive loss of cellular biological functions and increases the risk of age-related diseases. Cardiovascular diseases, some neurological disorders and cancers are generally classified as age-related diseases that affect the lifespan of individuals. These diseases result from the accumulation of cellular damage and reduced activity of protective stress response pathways, which can lead to inflammation and oxidative stress, which play a key role in the aging process. There is now increasing interest in the therapeutic effects of edible plants for the prevention of various diseases, including those associated with aging. It has become clear that the beneficial effects of these foods are due, at least in part, to the high concentration of bioactive phenolic compounds with low side effects. Antioxidants are the most abundant, and their high consumption in the Mediterranean diet has been associated with slower ageing in humans. Extensive human dietary intervention studies strongly suggest that polyphenol supplementation protects against the development of degenerative diseases, especially in the elderly. In this review, we present data on the biological effects of plant polyphenols in the context of their relevance to human health, ageing and the prevention of age-related diseases.

Traditional Chinese medicines and natural products targeting immune cells in the treatment of metabolic-related fatty liver disease

MAFLD stands for metabolic-related fatty liver disease, which is a prevalent liver disease affecting one-third of adults worldwide, and is strongly associated with obesity, hyperlipidemia, and type 2 diabetes. It encompasses a broad spectrum of conditions ranging from simple liver fat accumulation to advanced stages like chronic inflammation, tissue damage, fibrosis, cirrhosis, and even hepatocellular carcinoma. With limited approved drugs for MAFLD, identifying promising drug targets and developing effective treatment strategies is essential. The liver plays a critical role in regulating human immunity, and enriching innate and adaptive immune cells in the liver can significantly improve the pathological state of MAFLD. In the modern era of drug discovery, there is increasing evidence that traditional Chinese medicine prescriptions, natural products and herb components can effectively treat MAFLD. Our study aims to review the current evidence supporting the potential benefits of such treatments, specifically targeting immune cells that are responsible for the pathogenesis of MAFLD. By providing new insights into the development of traditional drugs for the treatment of MAFLD, our findings may pave the way for more effective and targeted therapeutic approaches.

Insights into the potential benefits of triphala polyphenols toward the promotion of resilience against stress-induced depression and cognitive impairment

In response to environmental challenges, stress is a common reaction, but dysregulation of the stress response can lead to neuropsychiatric disorders, including depression and cognitive impairment. Particularly, there is ample evidence that overexposure to mental stress can have lasting detrimental consequences for psychological health, cognitive function, and ultimately well-being. In fact, some individuals are resilient to the same stressor. A major benefit of enhancing stress resilience in at-risk groups is that it may help prevent the onset of stress-induced mental health problems. A potential therapeutic strategy for maintaining a healthy life is to address stress-induced health problems with botanicals or dietary supplements such as polyphenols. Triphala, also known as Zhe Busong decoction in Tibetan, is a well-recognized Ayurvedic polyherbal medicine comprising dried fruits from three different plant species. As a promising food-sourced phytotherapy, triphala polyphenols have been used throughout history to treat a variety of medical conditions, including brain health maintenance. Nevertheless, a comprehensive review is still lacking. Here, the primary objective of this review article is to provide an overview of the classification, safety, and pharmacokinetics of triphala polyphenols, as well as recommendations for the development of triphala polyphenols as a novel therapeutic strategy for promoting resilience in susceptible individuals. Additionally, we summarize recent advances demonstrating that triphala polyphenols are beneficial to cognitive and psychological resilience by regulating 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) receptors, gut microbiota, and antioxidant-related signaling pathways. Overall, scientific exploration of triphala polyphenols is warranted to understand their therapeutic efficacy. In addition to providing novel insights into the mechanisms of triphala polyphenols for promoting stress resilience, blood brain barrier (BBB) permeability and systemic bioavailability of triphala polyphenols also need to be improved by the research community. Moreover, well-designed clinical trials are needed to increase the scientific validity of triphala polyphenols' beneficial effects for preventing and treating cognitive impairment and psychological dysfunction.

Restorative effects of gallic acid against sub-chronic hepatic toxicity of co-exposure to zinc oxide nanoparticles and arsenic trioxide in male rats

Background and objectives

This study aimed to assess the effect of zinc oxide nanoparticles (ZNPs) and/or arsenic trioxide (ATO) exposure on the liver of adult male Sprague Dawley rats. Moreover, the probable ameliorative impact of gallic acid (GA) against ZNPs and ATO-induced hepatotoxicity and the possible underlying mechanisms were evaluated.

Methods

Sixty male Sprague Dawley rats were distributed into six groups. The 1^st and 2^nd groups were orally given distilled water (1 ml/kg) and 20 mg GA/kg b. wt, respectively. The 3^rd and 4^th groups were orally given 100 mg ZNPs/kg b. wt and 8 mg ATO/kg b. wt, respectively. The 5^th group was co-administered ZNPs and ATO at the doses mentioned above. The last one was co-administered ZNPs, ATO, and GA at the earlier described doses. All tested compounds were orally given once a day for 60 successive days. Then, 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 content of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) was evaluated. Moreover, Bcl-2 and Bax's reactive proteins were immunohistochemically detected, and Zn and As residual patterns in hepatic tissues were assessed.

Results

ZNPs, ATO, and ZNPs+ATO-exposed rats showed significantly (P < 0.001) elevated serum AST (219%, 233%, and 333%), ALT (300%, 400%, and 475%), ALP (169%, 205%, and 294%), and total bilirubin (42%, 68%, and 109%) compared to the control ones. On the other hand, a significantly (P < 0.001) declined SOD (58%, 49%, and 43%) and GPx (70%, 63%, and 56%) but increased MDA (133%, 150%, and 224%) was recorded in the hepatic tissues of ZNPs, ATO, and ZNPs+ATO exposed rats, respectively, relative to the control rats. Moreover, the hepatic tissues of the ZNPs, ATO, and ZNPs+ATO exposed rats showed a significant (P < 0.001) decrease in Bcl-2 (28%, 33%, and 23%) but elevation in Bax (217%, 267%, and 236%) immunoreactivities compared to the control rats. These findings were consistent with the microscopic alterations in the hepatic architecture and accumulation of Zn and As. Furthermore, a notable hyperlipidemic condition was recorded following ZNPs and/or ATO exposure. On the contrary, GA notably reduced hepatic enzymes compared to ZNPs+ATO-exposed rats. Additionally, GA markedly improved ZNPs+ATO-afforded liver tissue damage and apoptotic events.

Conclusion

Overall, GA oral dosing significantly mitigated the negative effects of ZNPs and ATO on the liver by improving the antioxidant defense system and controlling apoptotic changes.

Bombax ceiba Linn. leaf extract rich in phenolic compounds to mitigate non-alcoholic fatty liver-related complications in experimental model

OBJECTIVES

Obesity, diabetes mellitus, insulin resistance (IR), and hypertriglyceridemia are common features observed in non-alcoholic fatty liver diseases (NAFLD). There is a critical medical necessity to find novel therapeutics that can halt the development of NAFLD.

METHODS

Bombax ceiba Linn. leaf extract was prepared and its phytochemical profile was determined. Standard and high carbohydrate high-fat diets (HCHF) were prepared. Rats were fed HCHF for 18 weeks to induce a non-alcoholic fatty liver (NAFL) model. Forty male rats were divided into control, B. ceiba Linn. leaf extract, NAFL, prophylactic, and treated groups. Serum fasting blood sugar (FBS), insulin, insulin resistance (HOMA-IR), cholesterol, high-density lipoprotein (HDL), triglycerides (TG), low density lipoprotein (LDL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), intelectin-1 (ITLN1), p38 MAP kinase (MAPK), peroxisome proliferator-activated receptor alpha (PPAR-α), and interleukin-6 (IL-6) were evaluated.

RESULTS

Data obtained showed that HCHF-induced NAFL resulting in a significant increase in FBS, serum insulin, HOMA-IR, cholesterol, LDL, TG, ALT, AST, and IL-6 and a significant decrease in serum levels of HDL, ITLN1, p38 MAP kinase, and PPAR-α compared to the control group. The analysis of B. ceiba Linn. leaf extract showed high content of phenol compounds which may cause a significant decrease in the levels of FBS, insulin, HOMA-IR values, lipid profile, and levels of IL-6 while a significant increase in serum levels of LDL, ITLN1, p38 MAP kinase, and PPAR-α compared to the NAFL group.

CONCLUSIONS

B. ceiba Linn. Leaf extract is a highly protective and promising therapeutic agent against inflammation and oxidative stress in the NAFLD model induced by HCHF.

Anti-inflammatory and antioxidative effects of gallic acid on experimental dry eye: in vitro and in vivo studies

BACKGROUND

To investigate the anti-inflammatory and antioxidative effects of gallic acid (GA) on human corneal epithelial cells (HCECs) and RAW264.7 macrophages as well as its therapeutic effects in an experimental dry eye (EDE) mouse model.

METHODS

A cell counting kit-8 (CCK-8) assay was used to test the cytotoxicity of GA. The effect of GA on cell migration was evaluated using a scratch wound healing assay. The anti-inflammatory and antioxidative effects of GA in vitro were tested using a hypertonic model (HCECs) and an inflammatory model (RAW264.7 cells). The in vivo biocompatibility of GA was detected by irritation tests in rabbits, whereas the preventive and therapeutic effect of GA in vivo was evaluated using a mouse model of EDE.

RESULTS

In the range of 0-100 μM, GA showed no cytotoxicity in RAW264.7 cells or HCECs and did not delay the HCECs monolayer wound healing within 24 h. Ocular tolerance to GA in the in vivo irritation test was good after seven days. In terms of antioxidative activity, GA significantly reduced the intracellular reactive oxygen species (ROS) in lipopolysaccharide (LPS) activated RAW264.7 macrophages and HCECs exposed to hyperosmotic stress. Furthermore, after pre-treatment with GA, the expression levels of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NADPH quinone oxidoreductase-1 (NQO-1) were significantly upregulated in RAW264.7 macrophages. GA also exhibits excellent anti-inflammatory properties. This is mainly demonstrated by the ability of GA to effectively downregulate the nuclear transcription factor-κB (NF-κB) pathway in LPS-activated RAW264.7 macrophages and to reduce inflammatory factors, such as nitric oxide (NO), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α). In vivo efficacy testing results in a mouse model of EDE showed that GA can effectively prevent and inhibit the apoptosis of corneal epithelial cells (CECs), reduce inflammatory factors in the cornea and conjunctiva as well as protect goblet cells.

CONCLUSION

In vitro and in vivo results indicate that GA possesses potent anti-inflammatory and antioxidative properties with no apparent cytotoxicity within the range of 0-100 μM. It is a promising eye drop formulation for the effective prevention and treatment of dry eye disease (DED).

Gallic acid and/or cerium oxide nanoparticles synthesized by gamma-irradiation protect cisplatin-induced nephrotoxicity via modulating oxidative stress, inflammation and apoptosis

Cisplatin is one of the most significant anticancer. However, its use is associated with numerous toxicities especially nephrotoxicity. The main aim of this work was to examine the protective effect of Gallic acid (GA) and/or cerium oxide nanoparticles (CONPs) synthesized by gamma-irradiation on cisplatin-induced nephrotoxicity in rats. To do that, 48 adult male albino rats were separated into eight groups and received GA (100 mg/kg orally) and/or CONPs (15 mg/kg i. p.) for 10 days before injection with a single dose of cisplatin (7.5 mg/kg i. p.). The findings showed that cisplatin treatment impaired kidney functioning as shown by elevated serum levels of urea and creatinine. Additionally, the oxidative stress indicators (MDA and NO), levels of NF-kB, pro-inflammatory cytokines (IL1-and TNF-) and pro-apoptotic proteins (BAX and caspase-3) were raised after cisplatin injection, while levels of intrinsic anti-oxidants (CAT, SOD, and GSH) and anti-apoptotic protein (Bcl-2) were reduced. Moreover, renal toxicity was confirmed by alteration in normal histological architecture of the kidneys. On the other hand, pretreatment with CONPs and/or GA ameliorated cisplatin-induced nephrotoxicity as evidenced by improvement of renal function parameters and levels of oxidative stress, inflammatory and apoptotic markers in renal tissue along with the renal histopathological changes. This study clarifies how GA and CONPs protect against cisplatin-induced nephrotoxicity and demonstrates any potential synergism between them. Therefore, they can be considered as promising nephroprotective agents during chemotherapy.

Gallic acid impairs fructose-driven de novo lipogenesis and ameliorates hepatic steatosis via AMPK-dependent suppression of SREBP-1/ACC/FASN cascade

Accumulating evidence suggests that de novo lipogenesis is a typical characteristic facilitating nonalcoholic fatty liver disease (NAFLD) progression. Gallic acid (GA) is a naturally occurring phenolic acid with metabolic disease-related clinical significance and preclinical benefits. This study aimed to evaluate the anti-steatotic potentials of GA in a fructose-induced NAFLD mouse model featuring a hepatic lipogenic phenotype. The results revealed that GA alleviated hepatic steatosis, oxidative stress, and inflammatory response in fructose-fed mice. Mechanistically, GA treatment restored AMP-activated protein kinase α (AMPKα) phosphorylation, resulting in downregulations of pro-lipogenic factors, including sterol regulatory element binding protein-1 (SREBP-1), fatty acid synthetase (FASN), and acetyl-CoA carboxylase (ACC), in hepatocytes of mice and in vitro. Furthermore, computational docking analysis indicated that GA could directly interact with AMPKα/β subunits to stabilize its activation. These results suggest that GA ameliorates fructose-induced hepatosteatosis by restraining hepatic lipogenesis via AMPK-dependent suppression of the SREBP-1/ACC/FASN cascade. Altogether, this study demonstrates that GA supplement may be a promising therapeutic strategy in NAFLD, especially in the subset with enhanced hepatic lipogenesis.

Selected Soybean Varieties Regulate Hepatic LDL-Cholesterol Homeostasis Depending on Their Glycinin:β-Conglycinin Ratio

Clinical studies indicate that the consumption of soybean protein might reduce cholesterol and LDL levels preventing the development of atherosclerotic cardiovascular diseases. However, soybean variety can influence soybean protein profile and therefore affect soybean protein health-promoting properties. This study investigated the composition and effects of nineteen soybean varieties digested under simulated gastrointestinal conditions on hepatic cholesterol metabolism and LDL oxidation in vitro. Soybean varieties exhibited a differential protein hydrolysis during gastrointestinal digestion. Soybean varieties could be classified according to their composition (high/low glycinin:β-conglycinin ratio) and capacity to inhibit HMGCR (IC50 from 59 to 229 µg protein mL−1). According to multivariate analyses, five soybean varieties were selected. These soybean varieties produced different peptide profiles and differently reduced cholesterol concentration (43−55%) by inhibiting HMGCR in fatty-acid-stimulated HepG2 hepatocytes. Selected digested soybean varieties inhibited cholesterol esterification, triglyceride production, VLDL secretion, and LDL recycling by reducing ANGPTL3 and PCSK9 and synchronously increasing LDLR expression. In addition, selected soybean varieties hindered LDL oxidation, reducing the formation of lipid peroxidation early (conjugated dienes) and end products (malondialdehyde and 4-hydroxynonenal). The changes in HMGCR expression, cholesterol esterification, triglyceride accumulation, ANGPTL3 release, and malondialdehyde formation during LDL oxidation were significantly (p < 0.05) correlated with the glycinin:β-conglycinin ratio. Soybean varieties with lower glycinin:β-conglycinin exhibited a better potential in regulating cholesterol and LDL homeostasis in vitro. Consumption of soybean flour with a greater proportion of β-conglycinin may, consequently, improve the potential of the food ingredient to maintain healthy liver cholesterol homeostasis and cardiovascular function.

Luteolin ameliorates palmitate-induced lipotoxicity in hepatocytes by mediating endoplasmic reticulum stress and autophagy

Abnormal accumulation of lipids in liver leads to uncontrolled endoplasmic reticulum (ER) stress and autophagy. Luteolin is known to have antioxidant, anti-inflammatory, and anti-cancer properties, but whether it protects against lipotoxicity in liver remains unclear. In this study, we challenged AML12 liver cells and mouse primary hepatocytes with palmitic acid (PA) with or without luteolin pretreatment. In the presence of PA, reactive oxygen species (ROS) production was increased at 3 h, followed by enhancement of expression of p-PERK, ATF4, p-eIF2α, CHOP, and TXNIP (ER stress markers) and p-p62 and LC3II/LC3I ratio (autophagy markers), in both primary hepatocytes and AML12 cells. When PA treatment was extended up to 24 h, apoptosis was induced as evidenced by an increase in caspase-3 activation. RFP-GFP-LC3B transfection further revealed that the fusion of autophagosomes with lysosomes was damaged by PA. With luteolin treatment, the expression of antioxidant enzymes, i.e., heme oxygenase-1 and glutathione peroxidase, was upregulated, and PA-induced ROS production, ER stress, and cell death were dose-dependently ameliorated. Luteolin could also reverse the damage caused to autophagic flux. These results indicate that luteolin protects hepatocytes against PA assault by enhancing antioxidant defense, which can attenuate ER stress and autophagy as well as promote autophagic flux.

Effect of Structured Phenolic Lipids with EPA/DHA and Gallic Acid against Metabolic-Associated Fatty Liver Disease (MAFLD) in Mice

Obesity is the leading risk factor for developing metabolic (dysfunction)-associated fatty liver disease (MAFLD). The food industry has an essential role in searching for new strategies to improve primary food sources to revert some of the metabolic alterations induced by obesity. There is consistent evidence that long-chain polyunsaturated fatty acids (n-3 LCPUFA) belonging to the n-3 series, i.e., eicosapentaenoic (20:5n-3, EPA) and docosahexaenoic (22:6n-3, DHA) acids, could revert some alterations associated with obesity-induced metabolic diseases. A relevant tool is the synthesis of structured acylglycerols (sAG), which include EPA or DHA at the sn-2 position. On the other hand, it has been reported that a crucial role of antioxidants is the reversion of MAFLD. In this work, we studied the effects of new molecules incorporating gallic acid (GA) into EPA/DHA-rich structured lipids. Mice were fed with a high-fat diet (60%) for three months and were then divided into five groups for supplementation with sAG and sAG structured with gallic acid (structured phenolic acylglycerols, sPAG). sPAG synthesis was optimized using a 2²-screening factorial design based on the response surface methodology (RSM). Our results show that treatment of sPAG was effective in decreasing visceral fat, fasting glycemia, fasting insulin, suggesting that this new molecule has a potential use in the reversal of MAFLD-associated alterations.

Therapeutic Effects of Heterotrigona itama (Stingless Bee) Bee Bread in Improving Hepatic Lipid Metabolism through theActivation of the Keap1/Nrf2 Signaling Pathway in an Obese Rat Model

Bee bread (BB) has traditionally been used as a dietary supplement to treat liver problems. This study evaluated the therapeutic effects of Heterotrigona itama BB from Malaysia on obesity-induced hepatic lipid metabolism disorder via the regulation of the Keap1/Nrf2 pathway. Male Sprague Dawley rats were fed with either a normal diet or high-fat diet (HFD) for 6 weeks to induce obesity. Following 6 weeks, obese rats were treated either with distilled water (OB group), BB (0.5 g/kg body weight/day) (OB + BB group) or orlistat (10 mg/kg body weight/day) (OB + OR group) concurrent with HFD for another 6 weeks. BB treatment suppressed Keap1 and promoted Nrf2 cytoplasmic and nuclear translocations, leading to a reduction in oxidative stress, and promoted antioxidant enzyme activities in the liver. Furthermore, BB down-regulated lipid synthesis and its regulator levels (SIRT1, AMPK), and up-regulated fatty acid β-oxidation in the liver of obese rats, being consistent with alleviated lipid levels, improved hepatic histopathological changes (steatosis, hepatocellular hypertrophy, inflammation and glycogen expression) and prevented progression to non-alcoholic steatohepatitis. These results showed the therapeutic potentials of H. itama BB against oxidative stress and improved lipid metabolism in the liver of obese rats possibly by targeting the Keap1/Nrf2 pathway, hence proposing its role as a natural supplement capable of treating obesity-induced fatty liver disease.

Biological Mechanisms and Related Natural Inhibitors of CD36 in Nonalcoholic Fatty Liver

Non-alcoholic fatty liver disease (NAFLD), a spectrum of liver disorders from non-alcoholic fatty liver (NAFL) to the more severe non-alcoholic steatohepatitis (NASH), is the leading etiology of chronic liver disease and its global prevalence is increasing. Hepatic steatosis, a condition marked by an abnormal buildup of triglycerides in the liver, is the precursor to NAFLD. Differentiated cluster 36 (CD36), a scavenger receptor class B protein, is a membrane receptor that recognizes multiple lipid and non-lipid ligands. It is generally agreed that CD36 contributes significantly to hepatic steatosis by taking part in fatty acid uptake as well as triglyceride storage and secretion. While there has not been any conclusive research on how CD36 inhibitors prevent NAFLD from progressing and no clinically approved CD36 inhibitors are currently available for use in NAFLD, CD36 remains a target worthy of further investigation in NAFLD. In recent years, the potential role of natural products acting through CD36 in treating non-alcoholic fatty liver disease has attracted much attention. This paper offers an overview of the pathogenesis of CD36 in NAFLD and summarizes some of the natural compounds or extracts that are currently being investigated for modulating NAFLD via CD36 or the CD36 pathway, providing an alternative approach to the development of CD36-related drugs in NAFLD.

Portulaca oleracea L. Extract Regulates Hepatic Cholesterol Metabolism via the AMPK/MicroRNA-33/34a Pathway in Rats Fed a High-Cholesterol Diet

This study examined the effect of extruded Portulaca oleracea L. extract (PE) in rats fed a high-cholesterol diet through the AMP-activated protein kinase (AMPK) and microRNA (miR)-33/34a pathway. Sprague–Dawley rats were randomized into three groups and fed either a standard diet (SD), a high-cholesterol diet containing 1% cholesterol and 0.5% cholic acid (HC), or an HC diet containing 0.8% PE for 4 weeks. PE supplementation improved serum, liver, and fecal lipid profiles. PE upregulated the expression of genes involved in cholesterol efflux and bile acids’ synthesis such as liver X receptor alpha (LXRα), ATP-binding cassette subfamily G5/G8 (ABCG5/8), and cholesterol 7 alpha-hydroxylase (CYP7A1), and downregulated farnesoid X receptor (FXR) in the liver. In addition, hepatic gene expression levels of apolipoprotein A-l (apoA-1), paraoxonase 1 (PON1), ATP-binding cassette subfamily A1/G1 (ABCA1/G1), lecithin-cholesterol acyltransferase (LCAT), and scavenger receptor class B type 1 (SR-B1), which are related to serum high-density lipoprotein cholesterol metabolism, were upregulated by PE. Furthermore, hepatic AMPK activity in the PE group was higher than in the HC group, and miR-33/34a expression levels were suppressed. These results suggest that PE improves the cholesterol metabolism by modulating AMPK activation and miR-33/34a expression in the liver.

The protective effect of selenoprotein M on non-alcoholic fatty liver disease: the role of the AMPKα1-MFN2 pathway and Parkin mitophagy

Non-alcoholic fatty liver disease (NAFLD) is related to a dysregulation of mitophagy, a process that is not fully understood. Parkin-related mitophagy can sustain mitochondrial homeostasis and hepatocyte viability. Herein, we report that selenoprotein M (SELENOM) plays a central role in maintaining mitophagy in high-fat diet (HFD)-mediated NAFLD. We show that SELENOM was significantly downregulated in the liver of HFD-fed mice. SELENOM deletion aggravated HFD-mediated hepatic steatosis, inflammation, and fibrosis; accompanied by enhanced fatty acid oxidation and oxidative stress in the liver. Molecular analyses show that lipotoxicity was related to increased mitochondrial apoptosis as evidenced by enhanced mitochondrial ROS production, and attenuation of mitochondrial potential in the liver of HFD-fed SELENOM-/- mice. Additionally, SELENOM deletion reduced mitophagy and aggravated hepatic injury in NAFLD. Mechanistically, SELENOM overexpression activated Parkin-mediated mitophagy to reduce mitochondrial apoptosis and remove HFD-damaged mitochondria. We further found that SELENOM regulates Parkin expression via the AMPKα1-MFN2 pathway; blockade of AMPKα1 prevented SELENOM activation of Parkin-mediated mitophagy. Our work identified SELENOM downregulation as a possible explanation for the defective mitophagy in NAFLD. Thus, targeting SELENOM may be potential new therapeutic modalities for NAFLD treatment.

Aged green tea reduces high-fat diet-induced fat accumulation and inflammation via activating the AMP-activated protein kinase signaling pathway

Background

Obesity is a global public health concern and increases the risk of metabolic syndrome and other diseases. The anti-obesity effects of various plant-derived bioactive compounds, such as tea extracts, are well-established. The mechanisms underlying the anti-obesity activity of Jinxuan green tea (JXGT) from different storage years are still unclear.

Objective

The aim of this study was to evaluate the effects of JXGTs from three different years on the high fat diet (HFD)-fed mouse model.

Design

The mice were divided into six groups, the control group received normal diet and the obese model group received HFD. We analyzed the effects of JXGTs from 2005, 2008, and 2016 on HFD-fed obese mice over a period of 7 weeks.

Results

The JXGTs reduced the body weight of the obese mice, and also alleviated fat accumulation and hepatic steatosis. Mechanistically, JXGTs increased the phosphorylation of AMP-activated protein kinase (p-AMPK)/AMP-activated protein kinase (AMPK) ratio, up-regulated carnitine acyl transferase 1A (CPT-1A), and down-regulated fatty acid synthase (FAS), Glycogen synthase kinase-3beta (GSK-3β), Peroxisome proliferator-activated receptor-gamma co-activator-1alpha (PGC-1α), Interleukin 6 (IL-6), and Tumour necrosis factor alpha (TNFα). Thus, JXGTs can alleviate HFD-induced obesity by inhibiting lipid biosynthesis and inflammation, thereby promoting fatty acid oxidation via the AMPK pathway.

Discussion

The anti-obesity effect of three aged JXGTs were similar. However, JXGT2016 exhibited a more potent activation of AMPK, and JXGT2005 and JXGT2008 exhibited a more potent inhibiting glycogen synthase and inflammation effect. Furthermore, the polyphenol (–)-epicatechin (EC) showed the strongest positive correlation with the anti-obesity effect of JXGT.

Conclusions

These findings demonstrate that JXGT treatment has a potential protection on HFD-induced obesity mice via activating the AMPK/CPT-1A and down-regulating FAS/GSK-3β/PGC-1α and IL-6/TNFα. Our study results also revealed that different storage time would not affect the anti-obesity and anti-inflammation effect of JXGT.

Graphical abstract

Liraglutide inhibits receptor for advanced glycation end products (RAGE)/reduced form of nicotinamide-adenine dinucleotide phosphate (NAPDH) signaling to ameliorate non-alcoholic fatty liver disease (NAFLD) in vivo and vitro

The study was designed to investigate the effects of liraglutide and reveal its action mechanism associated with RAGE/NAPDH in NAFLD. The liver tissue was collected for HE, Masson, and ROS staining. Apoptosis levels were detected through TUNEL staining and ROS levels were evaluated through ROS staining. The expression levels of c-Jun N-terminal kinase (JNK) and transforming growth factor-β (TGF-β) were detected through Western blot. JNK and the expression of Collagenα1, Collagenα2 and connective tissue growth factor (CTGF) were detected through RT-qPCR and Western blot and the expression in mouse liver stellate cells (JS-1) cells were evaluated through immunofluorescence staining. We detected the effects of liraglutide on NAFLD in high-fat diet (HFD)-fed mice. Liraglutide treatment improved bridging fibrosis and liver function, as well as lessening ROS levels and the protein levels of RAGE, NOX1, NOX2 and NOX4. In PA and H2O2-induced AML12 cells, liraglutide treatment was able to decrease cell apoptosis, ROS levels and the levels of inflammatory factors including tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, while it effects were reversed by the induction of RAGE overexpression or NOX2 overexpression. In JS-1 cells treated with medium culturing AML12 cells, liraglutide markedly suppressed cell proliferation and activation, while RAGE overexpression or NOX2 overexpression blunted these effects of liraglutide. Taken together, liraglutide exerts a protective role in improving liver injury caused by HFD, which could be related to decreased apoptosis and oxidative stress of liver cells, as well as decreased proliferation and activation of hepatic stellate cells through RAGE/NOX2.

Gallic acid attenuates cadmium mediated cardiac hypertrophic remodelling through upregulation of Nrf2 and PECAM-1signalling in rats

Gallic acid (GA) is an abundant natural polyphenolic compound found in vegetable and fruits that reduces the cardiac disease risk factor. This study aims to evaluate GA's role on cadmium (Cd) induced cardiac remodelling in experimental rats. Male Wistar rats were exposed to Cd (15 ppm) in drinking water and administered with GA orally (15 mg/kg/d) for 60 days. The results showed that GA regulated the lipid profile and reduced the LDL to 57 % compared with Cd treated rats. GA inhibited cardiac marker enzymes activity of CK-NAC (to 72.7 %) and CK-MB (to 100.3 %). Moreover, GA attenuated lipid peroxidation and enhanced the cardiac glutathione S transferase (GST) activity (89.2 %), glutathione peroxidase (GPx) (87 %), superoxide dismutase (SOD) (88.4 %) and catalase (CAT) activity (86.5 %). Histopathological examination showed that GA impaired the ventricular hypertrophy and fibrotic proliferation induced by Cd in rats. The combination of GA + Cd, decreased the gene expression of ANP (1-fold), BNP (0.5-fold) and β- MHC (0.9-fold). Furthermore, GA significantly reduced the expression of profibrotic (TGF-β) and proinflammatory (MCP-1) gene in Cd intoxicated rats. GA upregulated the expression of Nrf2 (2-fold), HO-1 (3-fold), and PECAM-1 (0.6-fold), which augments the detoxifying enzyme activity and cellular immunity in Cd intoxicated rats. The increased protein expression of Nrf2, PECAM-1 and decreased AKT-1 levels confirmed the mechanical action of GA during the hypertrophic condition. Thus, our results suggest that GA could act as a potential therapeutic agent regulating Nrf2 and PECAM-1 signalling pathways, thereby ameliorating Cd-induced pathological cardiac remodelling.

Gallic acid for cancer therapy: Molecular mechanisms and boosting efficacy by nanoscopical delivery

Cancer is the second leading cause of death worldwide. Majority of recent research efforts in the field aim to address why cancer resistance to therapy develops and how to overcome or prevent it. In line with this, novel anti-cancer compounds are desperately needed for chemoresistant cancer cells. Phytochemicals, in view of their pharmacological activities and capacity to target various molecular pathways, are of great interest in the development of therapeutics against cancer. Plant-derived-natural products have poor bioavailability which restricts their anti-tumor activity. Gallic acid (GA) is a phenolic acid exclusively found in natural sources such as gallnut, sumac, tea leaves, and oak bark. In this review, we report on the most recent research related to anti-tumor activities of GA in various cancers with a focus on its underlying molecular mechanisms and cellular pathwaysthat that lead to apoptosis and migration of cancer cells. GA down-regulates the expression of molecular pathways involved in cancer progression such as PI3K/Akt. The co-administration of GA with chemotherapeutic agents shows improvements in suppressing cancer malignancy. Various nano-vehicles such as organic- and inorganic nano-materials have been developed for targeted delivery of GA at the tumor site. Here, we suggest that nano-vehicles improve GA bioavailability and its ability for tumor suppression.

Nutrigenomics of Dietary Lipids

Dietary lipids have a major role in nutrition, not only for their fuel value, but also as essential and bioactive nutrients. This narrative review aims to describe the current evidence on nutrigenomic effects of dietary lipids. Firstly, the different chemical and biological properties of fatty acids contained both in plant- and animal-based food are illustrated. A description of lipid bioavailability, bioaccessibility, and lipotoxicity is provided, together with an overview of the modulatory role of lipids as pro- or anti-inflammatory agents. Current findings concerning the metabolic impact of lipids on gene expression, epigenome, and gut microbiome in animal and human studies are summarized. Finally, the effect of the individual’s genetic make-up on lipid metabolism is described. The main goal is to provide an overview about the interaction between dietary lipids and the genome, by identifying and discussing recent scientific evidence, recognizing strengths and weaknesses, to address future investigations and fill the gaps in the current knowledge on metabolic impact of dietary fats on health.

Production of ROS by Gallic Acid Activates KDM2A to Reduce rRNA Transcription

Metformin, which is suggested to have anti-cancer effects, activates KDM2A to reduce rRNA transcription and proliferation of cancer cells. Thus, the specific activation of KDM2A may be applicable to the treatment of cancers. In this study, we screened a food-additive compound library to identify compounds that control cell proliferation. We found that gallic acid activated KDM2A to reduce rRNA transcription and cell proliferation in breast cancer MCF-7 cells. Gallic acid accelerated ROS production and activated AMPK. When ROS production or AMPK activity was inhibited, gallic acid did not activate KDM2A. These results suggest that both ROS production and AMPK activation are required for activation of KDM2A by gallic acid. Gallic acid did not reduce the succinate level, which was required for KDM2A activation by metformin. Metformin did not elevate ROS production. These results suggest that the activation of KDM2A by gallic acid includes mechanisms distinct from those by metformin. Therefore, signals from multiple intracellular conditions converge in KDM2A to control rRNA transcription. Gallic acid did not induce KDM2A-dependent anti-proliferation activity in non-tumorigenic MCF10A cells. These results suggest that the mechanism of KDM2A activation by gallic acid may be applicable to the treatment of breast cancers.