gallic acid

Cerebral ischemia activates harmful biochemical pathways that result in blood-brain barrier (BBB) breakdown and neuronal damage. Natural compounds such as chrysin and gallic acid (GA), known for their antioxidant and anti-inflammatory properties, may protect the BBB and reduce neuronal injury.

This study aimed to examine the effects of combining chrysin and GA on hippocampal neuronal damage, cognitive function, BBB integrity, and claudin-5 expression in a mouse model of cerebral ischemia.

Cerebral ischemia was induced through bilateral common carotid artery occlusion (BCCAO) for 30 minutes, followed by 48 hours of reperfusion. Chrysin (30 mg/kg, intraperitoneally), GA (50 mg/kg, intraperitoneally), and their combination were administered at the start of reperfusion and subsequently at 30 minutes and 1 hour. Hippocampal neuronal damage, spatial memory, Evans blue (EB) leakage, and claudin-5 expression were evaluated 48 hours after reperfusion.

Administration of chrysin, GA, and their combination significantly enhanced neuronal survival in the CA1, CA3, and dentate gyrus (DG) regions (P < 0.001). The combination diminished neurological deficit scores (1.5 ± 0.22 vs. control 3.5 ± 0.56, P < 0.05) and escape latency time (12.8 ± 4.5 vs. control 40 ± 4.82 seconds, P < 0.01). Likewise, these interventions significantly reduced EB leakage (3.46 ± 0.62 vs. control 11.28 ± 0.98 μg/g of brain tissue) and upregulated claudin-5 expression (38% ± 1.29 vs. control 10.75% ± 1.65, P < 0.001).

This study demonstrated that the combined treatment of chrysin and GA synergistically promoted hippocampal neuron survival, improved neurological function, and maintained BBB integrity by upregulating claudin-5 expression. We suggest that this therapeutic approach may offer potential benefits for stroke patients, though further experimental and clinical investigation is required to confirm its efficacy.

Gallic acid (GA) is a powerful antioxidant extracted from plants of the Brazilian Cerrado. Oxidative stress plays an important role in the occurrence of radiation-induced osteonecrosis in patients treated for head and neck cancer. There is a need to develop research aimed at developing complementary therapies to prevent or reverse bone damage. The aim of the present study was to investigate the effect of GA in preosteoblasts exposed to therapeutic ionizing radiation. MC3T3-E1 preosteoblast cells were treated with 10 µM GA and exposed to 6 Gy ionizing radiation. We performed in vitro assays of cell proliferation, oxidative stress analysis by detection of reactive oxygen species, and alkaline phosphatase assay. GA at lower concentrations was able to significantly increase proliferation and inhibit radiation-induced generation of reactive oxygen species in osteoblast precursor cells, despite ionizing radiation-induced injury. Furthermore, GA significantly increased alkaline phosphatase at a dose of 6 Gy. The findings suggested that GA could attenuate ionizing radiation-induced injuries in osteoblast precursor cells. Moreover, in vivo studies are needed to better investigate the role of GA in osteonecrosis, especially in cancer patients undergoing radiotherapy or taking antiresorptive drugs.

Plantago is a diverse genus of the Plantaginaceae family. Plantago lanceolata L. (P. lanceolata) and Plantago major L. (P. major) are used commercially worldwide as a traditional treatment for many diseases. A sensitive, simple, and reliable high-performance liquid chromatography (HPLC) method was developed to simultaneously quantify the three active ingredients: apigenin, catalpol, and gallic acid in P. lanceolata and P. major. 

HPLC analysis was carried out using C8 and C18 columns. The mobile phase comprised acetonitrile, orthophosphoric acid, or formic acid (different ratio V/V) with flow rates of 0.4, 0.8, and 1 mL/min. The eluted peaks were detected at 204, 210, 256, and 330 nm. The crude extracts were separated using the liquid-liquid extraction method.

HPLC analysis was performed using the C8 column with the mobile phase consisting of acetonitrile–orthophosphoric acid (1:1%) at a 1 mL/min flow rate. The detection of the eluted peaks was observed at 204 nm. Using this protocol, the detection and quantification limits for apigenin, catalpol, and gallic acid were 0.007 and 0.022 μg/mL, 0.04 and 0.14 μg/mL, 0.02 and 0.073 μg/mL, respectively. The calibration curve’s correlation coefficient indicated good linearity (r>0.9996, 0.9991, and 0.9978), with average recoveries for the three compounds between 100.02, 95.98, and 108.30%, respectively. Meanwhile, the intra-day and inter-day accuracy averages ranged from 100.07 to 99.95%, respectively. The results showed that using dichloromethane extracts of Plantago species leaves produced the highest yield of apigenin (1.08 and 0.58 μg/mg). At the same time, gallic acid was more abundant in methanolic, butanol, and aqueous extracts of P. lanceolata (3.33 μg/mg) and P. major (3.95, 4.34, and 4.72 μg/mg). The aqueous extract of P. lanceolata leaf and P. major root also showed more catalpol content (9.339 and 2.451 μg/mg). 

The developed method indicated reliable results with reproducibility, high accuracy in an analytical run, repeatability, acceptable intermediate precision, reproducibility, and stability of these working solutions. To the best of our knowledge, this study is the first report for the simple, simultaneous quantification of three compounds in Plantago spp. using HPLC.

Gastrointestinal (GI) mucositis is one of the serious side effects of methotrexate (MTX) treatment. It is known that oxidative stress plays an important role in drug-induced side effects.

The present study aimed to assess the effect of gallic acid (GA) against MTX-induced intestinal mucositis in male Wistar rats.

Twenty-eight adult male Wistar rats were randomly divided into 4 groups (n = 7), including (1) control group; (2) GA group (gallic acid: 30 mg/kg/day, orally); (3) MTX group [20 mg/kg, intra peritoneal (IP)]; and (4) (MTX + GA) group (MTX: 20 mg/kg, IP and gallic acid: 30 mg/kg/day, orally). Then amounts of malondialdehyde (MDA), nitric oxide (NO), glutathione peroxidase (GPx), glutathione (GSH), superoxide dismutase (SOD), interleukin 2 (IL-2) and interleukin 6 (IL-6) were analyzed in serum samples and then the histopathological examinations of the duodenum and jejunum of animals groups.

The results showed that treatment with GA significantly reduced the MTX-induced elevation of serumMDA(P < 0.001), NO (P < 0.001), IL-2 (P < 0.001) and IL-6 (P < 0.001) contents and increased MTX-induced reduction in GSH (P < 0.001) content, GPx (P < 0.001) and SOD (P < 0.001) activity. In addition, the histopathological results showed that MTX leads to intestinal tissue damage, and gallic acid can remarkably improve the pathological changes.

Our results indicate that gallic acid can mitigate oxidative stress and pro-inflammatory parameters and also moderately prevent histopathological damage of the small intestine of rats exposed to MTX.

Leishmaniasis is a parasitic disease caused by the Leishmania parasite, transmitted through the bite of an infected sandfly. The disease presents in four primary clinical forms: visceral, cutaneous, diffuse cutaneous, and post-kala-azar dermal leishmaniasis. The clinical manifestations vary depending on the Leishmania species and the host's immune response. Current treatments include antileishmanial drugs such as amphotericin B, antimonials, sitamaquine, pentamidine, paromomycin, and miltefosine. However, these drugs present challenges, including resistance to pentavalent antimonials and nephrotoxicity. The World Health Organization recommends exploring plants as therapeutic agents due to their efficacy and affordability. Conyza Canadensis, a biennial plant, has been utilized for wound healing and has shown efficacy against both gram-positive and gram-negative bacteria. This study aimed to investigate the anti-leishmanial effect of extracts from C. canadensis on the Iraqi strain of Leishmania tropica.

In this experimental study, the extracts were prepared as stock solutions and sub-cultured in RPMI-1640 medium. The cells were incubated in tissue culture flasks and treated with various concentrations of SSG and aqueous/alcoholic extracts. The anti-leishmanial activity of these extracts was evaluated using the sandwich enzyme-linked immunosorbent assay (ELISA) technique. The findings indicated that the extracts possessed anti-leishmanial activity.

The Iraqi C. canadensis plant extract contained alkaloids, gallic acid, apigenin, chlorogenic acid, caffeic acid, quercetin, p-Coumaric acid, and glutathione. These compounds are known to reduce neopterin levels and enhance the immune response against L. tropica.

The extracts of C. canadensis demonstrate anti-leishmanial activity, correlated with neopterin levels, showing promise as an alternative therapy for leishmaniasis. Further research is necessary to establish their effectiveness.

Breast cancer is the most common type of cancer and one of the major causes of death among women. Many reports propose gallic acid as a candidate for cancer treatment due to its biological and medicinal effects as well as its antioxidant properties. This study aimed to assess the effects of metformin and gallic acid on human breast cancer (MCF-7) and normal (MCF-10) cell lines.

Experimental approach:

 MCF7 and MCF-10 cells were treated with various concentrations of metformin, gallic acid, and their combination. Cell proliferation, reactive oxygen species (ROS), as well as cell cycle arrest were measured. Autophagy induction was assessed using western blot analysis.

Metformin and gallic acid did not cause toxicity in normal cells. They had a stronger combined impact on ROS induction. Metformin and Gallic acid resulted in cell cycle arrest in the sub-G1 phase with G1 and S phase arrest, respectively. Increased levels of LC3 and Beclin-1 markers along with decreased P62 markers were observed in cancerous cells, which is consistent with the anticancer properties of metformin and gallic acid.

Conclusion and implications: 

The effects of metformin and gallic acid on cancerous cells indicate the positive impact of their combination in treating human breast cancer.

Ethylenediaminetetraacetic acid (EDTA), a widely used chelating agent, compromises the bond strength of resin-based sealers when used as a final irrigating solution. Hence, the push-out bond strength of AH Plus, a resin-based sealer, was analyzed when gallic acid, “a chelator” was used as a last irrigating solution.

Forty human single-rooted teeth were accessed and randomly assigned into 4 groups (n = 10): EA (17% EDTA), MA (7% maleic acid), GA (10% gallic acid), and SA (saline). After irrigation, the root canals were coated with AH Plus sealer and obturated using gutta-percha. The root canals were sectioned horizontally into coronal, middle, and apical thirds for evaluating the push-out bond strength. A universal testing machine with a compressive loading of 1 mm/min was employed to test the samples.

An increased push-out bond strength was noted with GA in coronal one-third compared to EA and SA but not significant compared to MA (P > 0.05). Similar observations were seen in the middle one-third; however, it was statistically significant compared to all other groups (P < 0.05). Also, the difference between the groups in the apical one-third was not significant. SA showed the lowest push-out bond strength than experimental groups, which was significant in all three sections (P < 0.05).

The final rinse of 10% gallic acid increased the push-out bond strength of AH Plus to the root dentin in all thirds of the root canal. Hence, gallic acid 10% might be an effective alternative solution in place of synthetic chelators.

Cadmium (CD) causes widespread and severe toxic effects on various tissues. Studies have shown that apoptosis, inflammation, and endoplasmic reticulum stress play a role in organ damage caused by CD. Phenolic compounds with strong antioxidant effects are found in various fruits and vegetables. One of these compounds is Gallic acid (GA), which is found both free and hydrolyzable in grapes, pomegranate, tea, hops, and oak bark. Result of various studies show that GA has active antioxidant, anti-inflammatory, and anti-apoptotic properties. In our study, we investigated the mechanism of the protective effect of GA on CD-induced hepatotoxicity in rats.  In this study, 50 adult male Sprague Dawley rats weighing approximately 200–250 g were used and the rats were divided into 5 groups: Control, CD, GA50+CD, GA100+CD, and GA100. The rats were treated with GA (50 and 100 mg/kg body weight), and Cd (6.5 mg/kg) was administrated to the rats for 5 consecutive days. The liver enzymes, TB levels in serum samples, oxidative stress, inflammation, ER stresses, apoptosis marker, histopathology, 8-OHDG, and caspase-3 positivity were analyzed.  CD administration significantly increased liver enzyme levels (AST, ALT, ALP, and LDH), MDA, IL-1-β, IFN-γ, TNF-α, IL-10, IL-6, GRP78, CHOP, ATF6, p -IRE1, sXBP, Bax mRNA expression, Caspase 3, and 8-OHdG expression (P<0.05). These values were found to be significantly lower in the Control, GA100+CD, and GA100 groups compared to the CD group (P<0.05). CD administration significantly decreased the expression levels of TB, IL-4, SOD, GSH, CAT, GPX, and Bcl-2 mRNA (P<0.05). These values were found to be significantly higher in the Control, GA100+CD, and GA100 groups compared to the CD group (P<0.05). The results of the present study indicated that GA prevented Cd-induced hepatic oxidative stress, inflammation, ER stress, apoptosis, and tissue damage in rats.

We previously reported that cadmium (Cd) inhibits osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). In addition, gallic acid (GA) improves BMSC differentiation. Here, we aim to study the ability of GA to prevent osteogenic inhibition induced by Cd.

In this experimental study, BMSCs were extracted and purified from Wistar rats and their viability was determined in the presence of Cd and GA. The results indicated that 1.5 μM Cd and 0.25 μM of GA were appropriate for further investigation. After 20 days in osteogenic medium, matrix production was analysed by alizarin red, calcium content, and alkaline phosphatase (ALP) activity. Osteogenic-related genes and collagen 1A1 (COL1A1) protein expressions were investigated. The preventive effect of GA on oxidative stress and metabolic change induced by Cd was estimated.

GA counteracted the inhibitory effect of Cd on matrix production and significantly (P=0.0001) improved the osteogenic differentiation ability of BMSCs. Also, GA prevented the toxic effect of Cd on osteogenic-related gene expressions and nullified the reducing effect of Cd on COL1Al and ALP activity. A significant reduction (P=0.0001) in malondialdehyde and lactic acid concentration showed that GA counteracted both oxidative stress and metabolic changes caused by Cd.

GA prevented the toxic effect of Cd, an environmental pollutant and a factor in osteoporosis.

Serum and glucocorticoid-induced kinase 1 (SGK1) is an enzyme that may play an important role in ischemic-reperfusion (I/R) injury and myocardial dysfunction. Although many studies have been conducted on individual antioxidants, little attention has been paid to the effects of co-administration of an antioxidant with an SGK1 inhibitor on cardiac function after I/R.

This study aimed to determine the effects of gallic acid (as an antioxidant) combined with an SGK1 inhibitor on I/R-induced cardiac dysfunction and inflammation. Sixty male Wistar rats were randomized into 6 groups, pretreated with gallic acid or vehicle for 10 days. Subsequently, the heart was isolated and exposed to I/R. In groups that received the SGK1 inhibitor, the heart was perfused with the SGK1 inhibitor GSK650394, 5 min before induction of ischemia. After that, cardiac function, inflammatory factors, and myocardial damage were evaluated.

The combination of these two compounds improved cardiac contractility, heart rate, rate pressure product, left ventricular developed pressure, left ventricular systolic pressure, perfusion pressure, and QRS voltage significantly (P < 0.05). In addition, concomitant therapy of these two agents reduced tumor necrosis factor-alpha and interleukin-6, and the activity of creatine kinase-MB, lactate dehydrogenase, and troponin-I (P < 0.05).

The results indicated that administration of gallic acid with the SGK1 inhibitor may have a potentiating effect on the improvement of cardiac dysfunction and I/R-induced inflammation.

This study aims to evaluatewhether biochemical alterations caused by methylglyoxal (MG), improves by the administration of gallic acid (GA), crocin (Cr), and metformin (MT) in the liver.

MGis produced naturally through various physiological processes, but high levels of MG cause inflammation in hepatocytes. Normal liver function is essential for maintaining glucose homeostasis.Gallic acid and crocincan reduce inflammation.

This experiment was done in 5 weeks. 50 male NMRI mice were randomly divided into 5 groups (n=10): 1) Control, 2) MG (600 mg/Kg/d, p.o.), 3) MG+GA (30 mg/kg/day, p.o.), 4) MG+Cr (60 mg/kg/day, p.o.), 5) MG+MT (150 mg/kg/day, p.o.). After oneweek of habituation, MG was administered for four weeks. Gallic acid, crocin, and metforminwere administeredin the lasttwo weeks. Biochemical and histologic evaluations were assessed after plasma collection and tissue samplepreparation.

Gallic acid and crocin-receivedgroups significantly reduced fasting blood glucose, total cholesterol,triglyceride levels, and elevatedinsulin sensitivity. Administration of MG exerted a marked increase inthe levels of hepatic enzymes.Treatment with gallic acid, crocin, and metformin significantly decreased them.The altered levels of inflammatory factors in the diabetic group were significantly improved in the diabetic-treated groups.High levels of steatosis and red blood cells(RBCs)accumulation in the MG groupmarkedly recovered in other treated mice.

Harmful effects of accumulated MG in the liver of diabetic micewere effectively attenuated by usinggallic acid and crocin

Oxidative stress and serum and glucocorticoid-induced Kinase 1 gene (SGK1) perform a central role in the consequences of ischemia in the heart. This research aimed to investigate the effect of coadministration of gallic acid and the GSK650394 (as SGK1 gene inhibitor) on the ischemic complications of a rat model of cardiac ischemia/reperfusion (I/R) injury. 

Sixty male Wistar rats were divided into 6 groups with or without pretreatment with gallic acid for 10 days. After that, the heart was isolated and perfused with Krebs-Henseleit solution. A 30 min of ischemia was performed followed by a 60 min reperfusion.  In 2 groups, GSK650394 was infused 5 min before ischemia induction. Ten minutes after reperfusion commencement, cardiac marker enzyme (CK-MB, LDH, and cTn-I) activities were measured in the cardiac perfusate. At the end of reperfusion, the activity of anti-oxidant enzymes (Catalase, Superoxide dismutase, and Glutathione peroxidase), lipid peroxidation (MDA), total anti-oxidant capacity (TAC), intracellular reactive oxygen species (ROS), infarct size, and SGK1 gene expression were measured in the heart tissue. 

The results indicated that dual therapy with both drugs significantly improved endogenous anti-oxidant enzyme activity and TAC more than each drug alone. However, the heart marker enzymes (CK-MB, LDH, and cTn-I), MDA, ROS, infarct size, and SGK1 gene expression were reduced significantly compared with the ischemic group. 

The results of this study suggest that concomitant administration of both drugs in the case of cardiac I/R injury may have a more beneficial effect than each one alone.

Breast cancer cells produce exosomes that promote tumorigenesis. The anticancer properties of gallic acid have been reported. However, the mechanism underlying its anticancer effect on the exosomal secretory pathway is still unclear. We investigated the effect of gallic acid on exosome biogenesis in breast cancer cell lines.

The cytotoxic effect of gallic acid on MCF-10a, MCF-7, and MDA-MD-231 cells was measured by MTT assay after 48 hours treatment. Expression of miRNAs including miRNA-21, -155, and 182 as well as exosomal genes such as Rab27a, b, Rab11, Alix, and CD63; along with HSP-70 (autophagy gene), was determined using Q-PCR. The subcellular distribution of it was monitored by flow cytometry analysis. Isolated exosomes were characterized by transmission and scanning electron microscopes and flow cytometry. Acetylcholinesterase activity is used to measure the number of exosomes in supernatants. In addition, autophagy markers including LC3 and P62 were measured by ELISA.

Data showed that gallic acid was cytotoxic to cells (P < 0.05). Gallic acid modulated expression of miRNAs and down-regulated transcript levels of exosomal genes and up-regulated the HSP-70 gene in three cell lines (P < 0.05). The surface CD63/total CD63 ratio as well as acetylcholinesterase activity decreased in treated cells (P < 0.05). The protein level of LC3 was increased in three cell lines, while the expression of P62 increased in MCF-7 and MDA-MB-231 cancer cell lines.

Together, gallic acid decreased the activity of the exosomal secretory pathway in breast cancer cell lines, providing evidence for its anti-cancer effects.