Influence of gallic acid on porcine neutrophils phosphodiesterase 4,IL-6,TNF-α and rat arthritis model

Our previous studies showed that the anti-inflammatory effects of Paeonia lactiflora roots extract may be mediated, at least in part, through its gallic acid content, and this effect may be regulated in part by an inhibition on c AMP-phosphodiesterase（PDE）. To explore the anti-inflammatory effect and mechanism, the influence of gallic acid on neutrophils PDE4 activity and expression, TNF-α and IL-6 content and rat arthritis model were further studied. PDE4 activity and gene express were calculated respectively by substrate c AMP change examined with HPLC and real-time RT-PCR. The concentration of IL-6 and TNF-α in supernatant were assayed by ELISA method. Model of rat arthritis was caused by complete Freund＇s adjuvant. Results showed that gallic acid had a dose-dependent restraint on PDE4 activity of neutrophils in vitro, promoted significantly PDE4 A expression（P〈0.01）, and had no influence on the expressions of PDE4 B and 4D. However, PDE4 C expression was not detected. Gallic acid could promote IL-6 release（P〈0.05）, and inhibit TNF-α release of neutrophils（P〈0.05）. The experiment in vivo showed that gallic acid had obvious restraint on local inflammation of animal model（P〈0.05）. Therefore, the anti-inflammatory effect of gallic acid may be mediated in part through an inhibition on PDE4 activity and further an increase of IL-6 and a decrease of TNF-α of neutrophils, and this effect seemed to have no relationship with PDE4 expression.

Inhibitory activities of extracts of Rumex dentatus, Commelina benghalensis, Ajuga bracteosa, Ziziphus mauritiana as well as their compounds of gallic acid and emodin against dengue virus

Objective: To investigate the inhibitory effects against dengue virus serotype 2(DENV-2) by five different fractions(extracted by methanol, ethanol, benzene, chloroform and n-hexane) of Rumex dentatus, Commelina benghalensis, Ajuga bracteosa and Ziziphus mauritiana, as well as their constituents(gallic acid, emodin, and isovanillic acid). Methods: All the samples were tested for cytotoxicity on baby hamster kidney cells by MTT assay and for anti-DENV-2 activity by plaque reduction neutralization assay using two DENV-2 doses(45 and 90 plaqueforming units or PFU). Results: All the samples except isovanillic acid exhibited significant prophylactic effects against DENV-2 infectivity(without cytotoxicity) when administered to cells before infection, but were not effective when given 6 h post-infection. The methanol extract of Rumex dentatus demonstrated the highest antiviral efficacy by inhibiting DENV-2 replication, with IC_(50) of 0.154 μg/mL and 0.234 μg/mL, when added before infection with 45 and 90 PFU of virus, respectively. Gallic acid also exhibited significant antiviral effects by prophylactic treatment prior to virus adsorption on cells, with IC_(50) of 0.191 μg/mL and 0.522 μg/mL at 45 and 90 PFU of DENV-2 infection, respectively. Conclusions: The highly potent activities of the extracts and constituent compounds of these plants against DENV-2 infectivity highlight their potential as targets for further research to identify novel antiviral agents against dengue.

A selective voltammetric detection for dopamine using poly(gallic acid) film modified electrode

The electrochemistry behavior of dopamine was investigated by cyclic voltammetry and differential pulse voltammetry at a poly (gallic acid) film modified glassy carbon electrode.Two electrons and two protons participated in the diffusion-controlled electrocatalytic oxidation of dopamine with a diffusion coefficient of 2.186×10^(-5) cm^2/s.The interference of ascorbic acid with the determination of dopamine could be efficiently eliminated.This work provided a simple approach to selectively and sensitively de...

Characterization of Gallic Acid Interaction with Human Serum Albumin by Spectral and Molecular Modeling Methods

The binding of drugs with human serum albumin（HSA） is a crucial factor influencing the distribution and bioactivity of drugs in the body.To understand the action mechanisms between gallic acid（GA,3,4,5-trihydroxybenzoic acid） and HSA,the binding of GA with HSA was investigated by a combined experimental and computational approach.The fluorescence properties of HSA and the binding parameters of GA collectively indicate that the binding is characterized by static quenching mechanism at one high affinity binding site.According to the estimated molecular distance between the donor（HSA） and the acceptor（GA）,the binding is related to the fluorescence resonance energy transfer.As indicated by the thermodynamic parameters,hydrophobic interaction plays a major role in the GA-HSA complex.Further,the experimental results reveal that GA is bound in the large hydrophobic cavity of subdomain IIA in the site I of HSA,which is well approved by molecular docking.

SYNTHESIS AND CHARACTERIZATION OF HYPERBRANCHED POLY(ESTER-AMIDE)S BASED ON GALLIC ACID AND DL-2-AMINOBUTYRIC ACID

A novel AB3-type monomer was prepared from gallic acid and DL-2-aminobutyric acid, and used for the synthesis of the biocompatible hyperbranched poly(ester-amide)s by self-polycondensation. The polymers were characterized via FTIR and NMR spectroscopy and thermal analysis, and the average degree of branching of the polymers was estimated to be 0.75. The polymers with abundant acetyl end groups were found to be amorphous with lower intrinsic viscosity, better thermal stability and excellent solubility.

Preparation of Gallic Acid-chitosan Copolymer and Its Antibacterial Activity against Staphylococcus Aureus and Escherichia Coli

To synthesize three different grafting ratios of gallic acid(GA)-chitosan(CS)copolymer by a free radical mediated grafting method,which is further applied to the field of antibacterial materials,crosslinking structures of the compound GA-CS copolymer were characterized,fully indicating that gallic acid is resoundingly grafted onto chitosan.The grafting ratios of three copolymers GA-CS are 45.71%(Ⅰ),36.12%(Ⅱ),and 18.96%(Ⅲ)were determined by UV-Vis spectrophotometer.The minimum inhibitory concentrations of three GA-CS copolymers are 30μg/mL against Escherichia coli and are ranged from 250 to 550μg/mL against Staphylococcus aureus.By counting viable bacterial colonies,it can be found that antibacterial property is preferable by increasing the grafting ratio of GA-CS copolymers.Findings of investigation on aforementioned bacteria experiment indicate that the CFU/mL values of GA-CS(Ⅰ,Ⅱ,Ⅲ)are 2.04×10^(6),7.56×10^(6),1.48×10^(7) to Staphylococcus aureus,and 2.96×10^(6),1.01×10^(7),2.14×10^(7) to Escherichia coli after 12 h treatment.In addition,the interaction process between GA-CS copolymer and bacteria can be observed through a transmission electron microscope.The specific manifestation is that the bacterial cell membranes are ruptured after being treated with the copolymer,which causes the cell contents to flow out,and the cell morphology is shrunk and out ofshape.

Properties and Anti-Ultraviolet Activity of Gallic Acid-Chitosan-Gelatin Mixed Gel

Hydrogel has high water content and structural similarity with natural extracellular matrix.So it has been widely studied and applied in the field of biomedicine.In order to further develop multifunctional hydrogels,we prepared mixed gels with antiultraviolet properties.This study found that the addition of polysaccharides and polyphenols was beneficial to the rheological,me-chanical properties,and biological activity of the protein.Chitosan(CS)could significantly improve the viscoelasticity,hardness,gel strength,thermal stability and crystallinity of gelatin.Interestingly,the addition of gallic acid(GA)could not only provide significant cross-linking effect,improve gel properties and microstructure,but also improve the UV resistance of the mixed gel.

Free and liposome form of gallic acid improves calvarial bone wound healing in Wistar rats

Objective:To evaluate the effect of free and liposome form of gallic acid on bone regeneration in critical defects in Wistar rats.Methods:Thirty-two female Wistar rats were divided into four study groups:group 1,negative control;group 2,positive control;group 3,gallic acid powder;group 4,gallic acid liposome.A critical-sized defect was created in all rats.Groups 2 to 4 had xenograft,autograft and membrane placement while negative control rats did not receive any treatment.The defect area was sutured and rats were kept alive for 30 d.At the end of the study,a bone specimen including the defect area was removed from calvaria.All specimens were evaluated under the stereomicroscope,then underwent histological analysis.Inflammatory cell counts,osteoblast,osteoclast counts,receptor activator of nuclear factorκ-B(RANKL),osteoprotegerin(OPG),runt-related transcription factor 2(Runx2),bone morphogenetic protein-2(BMP-2),and alkaline phosphatase were determined.Results:The biggest unhealed defect area was observed in the negative control group and the smallest was observed in the gallic acid liposome group.There were no differences between the positive control group vs.the gallic acid powder group and the gallic acid powder group vs.the gallic acid liposome group.The severity of inflammation was the highest in the negative control group and the lowest in the gallic acid liposome group with significant differences between the groups.All groups had similar osteoblast counts while osteoclast counts were the highest in the positive control group.Gallic acid groups had a lower number of osteoclasts compared with the positive control group.Runx2 and alkaline phosphatase levels were similar in the groups while OPG and BMP-2 levels exhibited a significant increase compared with the negative control group and the positive control group.RANKL was similar in the negative control group,the positive control group,and the gallic acid powder groups but decreased in the gallic acid liposome group.Conclusions:Gallic acid powder and liposome significantly improve bone regeneration in Wistar rats with calvarial defects.The improvement in healing is evident with decreased inflammation and RANKL expressions and increased OPG and BMP-2 expressions.

Simultaneous Determination of Gallic Acid and Cinnamic Acid Content in Rhubarb by HPLC

[Objective]The paper was to determine the contents of gallic acid and cinnamic acid in Chinese herb rhubarb by HPLC.[Method]High performance liquid chromatography(HPLC)was established with the following conditions:Thermo SCIENTIFIC Hypersil GOLD Dim column(4.6 mm×250 mm,5μm),mobile phase methanol-0.1%phosphoric acid solution,gradient elution,detection wavelength 278 nm,flow rate 1.0 mL/min,column temperature 30℃,injection volume 10 pL.[Result]The content of gallic acid and cinnamic acid in rhubarb was determined by HPLC,and they showed good linear relationship in the linear ranges of 0.125-1.250 pg(E2=0.9998)and 0.0382-0.3820μg(E2=0.9994),respectively.[Conclusion]A HPLC method is established to determine gallic acid and cinnamic acid content in rhubarb.The method will provide a scientific basis for quality control of rhubarb and its traditional Chinese medicine.

Gallic acid与DA-6强化黑麦草修复复合重金属(Cd、Pb、Cu、Zn)污染土壤的研究

用盆栽实验研究了Gallic acid与DA-6单独及耦合使用对黑麦草修复复合重金属污染土壤的影响。结果表明,Gallic acid与DA-6单独及耦合使用,能使黑麦草对重金属污染土壤中Cd、Zn的修复产生明显的促进作用,但对Pb、Cu的修复没有明显变化。当添加5 mmol/kg的Gallic acid时,黑麦草对Cd、Zn的富集量分别达到了15.9 mg/kg与1 660.8 mg/kg,富集系数较未添加Gallic acid时提高了93.9%,233.9%;同时添加10μmol/kg DA-6与5 mmol/kg Gallic Acid之后,黑麦草对Cd、Zn的富集量分别达到了18.8 mg/kg,1 680.5 mg/kg,富集系数较未添加DA-6时提高了18.2%与1.2%。

Simultaneous determination of gallic acid and p-coumaric acid in rat plasma by UPLC-MS/MS and its application to a comparative pharmacokinetic study after oral administration of monomer compound and red wine extract

A rapid,sensitive and selective ultra high performance liquid chromatography-tandem mass spectrometry(UPLCMS/MS)method was developed and validated for simultaneous determination of gallic acid(GA)and p-coumaric acid(CA)in rat plasma.Plasma samples were extracted by methanol and separated on an ACQUITY UPLC BEH C18 column(1.7μm,100 mm×2.1 mm)using gradient elution consisting of acetonitrile–0.2%formic acid within a runtime of 4.0 min.The detection was performed in multiple reaction monitoring(MRM)mode with negative ionization.The linear range was 20–20000 ng/mL for both GA and CA,with lower limits of quantification of 20 ng/mL.Intra-day and inter-day precisions were within 5.4%and 10.0%,respectively and the accuracy(relative error,RE,%)was less than 7.2%and–4.9%,respectively.The mean absolute extraction recoveries of both analytes and IS from rat plasma were all more than 82.6%.The validated method was successfully applied to the comparative pharmacokinetic study of GA and CA in rat plasma after oral administration of GA and CA monomers and red wine extract,respectively.It was found that both the area under the curve(AUC)and t1/2 of the two constituents were remarkably increased for red wine extract group than that in monomer group,indicating the priority of intake of red wine to active component monomer.

Gallic acid induced apoptotic events in HCT-15 colon cancer cells

AIM: To investigate the inhibitory action of diet-derived phenolic compound gallic acid(GA) against HCT-15 colon cancer cells.METHODS: The antiproliferative effect of GA against colon cancer cells was determined by performing thiazolyl blue tetrazolium bromide(MTT) assay. The colony forming ability of GA treated colon cancer cells was evaluated using the colony forming assay. The cell cycle changes induced by GA in HCT-15 cells were analyzed by propidium iodide staining. Levels of reactive oxygen species(ROS) and mitochondrial membrane potential of HCT-15 exposed to GA was assessed using 2',7'-dichlorfluorescein-diacetate and rhodamine-123 respectively, with the help of flow cytometry. Morphological changes caused by GA treatment in the colon cancer cells were identified by scanning electron microscope and photomicrograph examination. Apoptosis was confirmed using flow cytometric analysis of GA treated HCT-15 cells after staining with Yo-Pro-1.RESULTS: MTT assay results illustrated that GA has an inhibitory effect on HCT-15 cells with IC50 value of 740 μmol/L. A time-dependent inhibition of colony formation was evident with GA treatment. Cell cycle arrest was evident from the accumulation of GA treated HCT-15 cells at sub-G1 phase(0.98 ± 1.03 vs 58.01 ± 2.05)with increasing exposure time. Flow cytometric analysis of GA treated HCT-15 cells depicted early events associated with apoptosis like lipid layer breakage and fall in mitochondrial membrane potential apart from an increase in the generation of ROS which were in a time dependent manner. SEM and photomicrograph images of the GA-treated cells displayed membrane blebbing and cell shrinking characteristics of apoptosis. Further apoptosis confirmation by Yo-Pro-1 staining also showed the time-dependent increase of apoptotic cells after treatment.CONCLUSION: These results show that GA induced ROS dependent apoptosis and inhibited the growth of colon cancer cells.

Gallic Acid-loaded Cellulose Acetate Electrospun Nanofibers: Thermal Properties, Mechanical Properties, and Drug Release Behavior

The gallic acid-loaded electrospun cellulose acetate fibers were successfully prepared. The fiber containing 2.5% gallic acid was smooth surface but observed drug flake on the surface of the fiber when increasing drug content. The thermal properties, mechanical properties and drug release behavior of the fibers were investigated comparing to the corres-ponding films.

Science Letters:Effects of polyurethane matrices on fungal tannase and gallic acid production under solid state culture

The influence of the physical structure of polyurethane matrix as a support in a solid state culture in tannase production and gallic acid accumulation by Aspergillus niger Aa-20 was evaluated. Three different polyurethane matrices were used as the support: continuous, semi-discontinuous and discontinuous. The highest tannase production at 2479.59 U/L during the first 12 h of culture was obtained using the discontinuous matrix. The gallic acid was accumulated at 7.64 g/L at the discontinuous matrix. The results show that the discontinuous matrix of polyurethane is better for tannase production and gallic acid accumulation in a solid state culture bioprocess than the continuous and semi-discontinuous matrices.

Determination of Gallic Acid in Rotala rotundifolia and Shuijia Zhixue Capsule by HPLC

[Objectives] To establish a method for the determination of gallic acid in Shuijia Zhixue capsule and Rotala rotundifolia .[Methods] High performance liquid chromatography (HPLC) and Phenomenex C 18 column were used, the mobile phase was 0.1% phosphoric acid∶ methanol=85∶ 15, the flow rate was 0.5 mL/min, and the detection wavelength was 270 nm.[Results] In the range of (2-25)μg/mL , the concentration of gallic acid had a good linear relationship with the peak area, r =0.990 8;the average recovery was 96.88%.[Conclusions] The method was simple, sensitive and reproducible. It provided a basis for the analysis of gallic acid in Rotala rotundifolia and Shuijia Zhixue capsule and the establishment of quality detection methods in the future.

Research on Extraction Process of Gallic Acid from <i>Penthorum chinense</i>Pursh by Aqueous Ethanol

Penthorum chinense Pursh is rich in gallic acid, which has antioxidant, anti-inflammatory, anti-fungal and antitumor activities. In order to optimize their extraction conditions, various extraction parameters were chosen to identify their effects on gallic acid extraction. With extraction amount of gallic acid as index, based on single factor analysis, influence of solid/liquid ratio, ethanol concentration, fetch time and extraction temperature on extraction technology were investigated by orthogonal test. The optimization conditions for gallic acid extraction were determined as follows: ethanol concentration 60%, extraction time 2.5 h, temperature 90°C and solid/liquid ratio 1:30. The corresponding gallic acid content was 4.85%. This optimized extraction process was stable and feasible.

Allelopathic effects of gallic acid from Aegiceras corniculatum on Cyclotella caspia

High abundance of algae and eutrophication were observed in mangrove wetlands and these were estimated to be associated with root exudates of some specific mangrove plants to a certain extent. Root exudates form allelopathic effects from mangroves. The main secondary metabolites of Aegiceras corniculatum had been detected to be organic phenolic acids. Gallic acid had been isolated and identified from A. corniculatum. The half-maximal inhibitory concentration of gallic acid on alge Cyclotella caspia was tested as 15.46 mg/L. The effects on algal cell morphology were mainly shown as elongated cells, with no apparent cell inclusions, such as oil droplets, chloroplast. At a dose of 2 mg/L, gallic acid had a stimulative effect on the specific growth rate of algae on day 3. The contents of malondialdehyde, superoxide dismutase, soluble carbohydrates and chlorophyll a in algal cells showed an overall ＂low promotion and high suppression＂. Our results could provide preliminary and valuable reference on the complex influences of mangroves on microecology and microbial communities in the rhlzosphere system.

Gallic Acid: A Potential Anti-Cancer Agent

Cancer is one of the most devastating diseases worldwide and definitive therapeutics for treating cancer are not yet available despite extensive research efforts. The key challenges include limiting factors connected with traditional chemotherapeutics, primarily drug resistance, low response rates, and adverse side-effects. Therefore, there is a high demand for novel anti-cancer drugs that are both potent and safe for cancer prevention and treatment. Gallic acid(GA), a natural botanic phenolic compound, can mediate various therapeutic properties that are involved in anti-inflammation, anti-obesity, and anti-cancer activities. More recently, GA has been shown to exert anti-cancer activities via several biological pathways that include migration, metastasis, apoptosis, cell cycle arrest, angiogenesis, and oncogene expression. This review discusses two aspects, one is the anti-cancer potential of GA against different types of cancer and the underlying molecular mechanisms, the other is the bibliometric analysis of GA in cancer and tumor research. The results indicated that lung cancer, prostate cancer, stomach cancer, and colon adenocarcinoma may become a hot topic in further research. Overall, this review provides evidence that GA represents a promising novel, potent, and safe anti-cancer drug candidate for treating cancer.

Determination of Gallic Acid by Flow Injection Analysis Based on LuminoI-AgNO3-Ag NPs Chemiluminescence System

A novel flow injection procedure has been developed for the determination of gallic acid based on the en- hancement function for luminol-AgNO3-Ag NPs chemiluminescence （CL） system by gallic acid. The enhancement mechanism was proposed for the reinforcing effect of the gallic acid on the CL system. The UV-vis absorption spectrum and CL emission spectrum were applied to confirm the mechanism. The method is simple, rapid and sen- sitive with a detection limit of 5 × 10^-10 g.mL-l and a linear range of 8.0 × 10^-10- 1.0 × 10-7 g.mL-1. The relative standard deviation （RSD） is 1.3% for eleven measurements of 5 × 10^-8 g-mL-1 gallic acid. The method has been successfully applied to the determination of gallic acid in Chinese proprietary medicine--Jianmin Yanhou tablets and synthesized samples.

Flow-injection Chemiluminescence Sensor for the Determination of Gallic Acid by Immobilizing Luminol and Periodate on Anion-exchange Resin

A novel chemiluminescence (CL) sensor for the determination of gallic acid combined with flow injection analysis was developed by electrostatically immobilizing luminol and periodate on anion-exchange resins respectively. Gallic acid was sensed by its enhancing effect on the weak CL reaction between luminol and periodate, which were eluted from the ion exchange column. The possible reaction mechanism of the CL system was suggested and discussed. The response of the sensor to gallic acid concentration was linear over the range of 8.0×10 -9-1.0×10 -6 mol/L with a detection limit of 6.5×10 -9 mol/L (3σ). The relative standard deviation (RSD) for 7 repetitive determinations of gallic acid (1.0×10 -7 mol/L) was 1.8%. The sensor could be used for over 400 times determination with a good reproducibility.