Methyl gallate isolated from Mangifera pajang kernel induces proliferation inhibition and apoptosis in MCF-7 breast cancer cells via oxidative stress

Objective: To determine the lead bioactive compound in kernel extract of Mangifera pajang and its anti-cancer activity against human breast cancer cell lines with positive estrogen receptor (MCF-7). Methods: The methanolic extract of dried powder kernel of Mangifera pajang was exposed to column chromatography for isolation. The structural elucidation of the isolated compound was characterized using infrared, nuclear magnetic resonance, mass spectrometry. Furthermore, cytotoxicity, morphological changes, flow cytometry and cell cycle arrest analyses were performed to examine the mechanism of anti-proliferation and apoptosis induced by methyl gallate against MCF-7. Results: One compound was isolated from the methanolic extract of Mangifera pajang kernel and identified as methyl gallate. The flow cytometric results demonstrated induction of apoptosis in MCF-7 cells by three concentrations of methyl gallate. The cell cycle arrest showed a significant (P<0.05) decrease in cell progression at G 2/M phase of MCF-7 after treatment with 100 μM of methyl gallate. The cell percentage of early and late apoptosis was significant at 10 and 100 μM of methyl gallate. Also, methyl gallate treatment induced up-regulation of reactive oxygen species levels in MCF-7 cells with a reduction in superoxide dismutase levels. Conclusions: These findings indicate that isolated methyl gallate from Mangifera pajang kernel extracts induces growth inhibition and apoptosis in MCF-7 cells via up-regulating oxidative stress pathway.

Simultaneous determination of gallic acid，methyl gallate and ellagic acid in mouth rinse residues and the effect of residue-drying methods on their content / 国际药学研究杂志

Objective: To establish a method for the simultaneous determination of gallic acid(GA),methyl gal- late(MG)and ellagic acid(EA)in the residue of a gingival consolidation liquid(a mouth rinse preparation),and inves- tigate the effect of different residue-drying methods on the GA,MG and EA content in the residues. Methods: High per- formance liquid chromatography(HPLC)switching walvelength method was used to determine the GA,MG and EA con- tents. The column was Agilent Zorbax SB-C18(250 mm×4.6 mm,5 μm). The mobile phase was methanol(A)-0.05% phosphoric acid aqueous solution(B)in a gradient elution. The detection wavelength was 272 nm for GA/MG and 255 nm for EA. The flow rate was 1 ml/min,and the injection volume was 3 μl. Meanwhile,the residues were dried with the methods of sun drying,blast drying,vacuum drying and microwave vacuum drying,respectively and the GA,MG and EA contents in the residues were determined by the established HPLC method. Results: The linear ranges for GA,MG and EA were 1.280-4.608(r=0.9998),0.560-2.016(r=0.9998),0.1145-0.4122 μg(r=0.9997),respectively. The aver- age recoveries for GA,MG and EA were 99.97%,99.93% and 100.20%,with the RSD of 0.34%,2.30% and 0.93%,re- spectively. The contents of GA,MG and EA varied in quite a large range in the residues dried by different methods. Con- clusion: The established method is fast,simple and practicable,which could be used for the determination of GA,MG and EA in the residue of a gingival consolidation liquid. The drying methods could significantly affect the contents of GA, MG and EA in the residues,and the related results provide a reference for future studies.

The effects of EGCG and EGCG-3Me on the bonding stability of dentin-adhensive to intraradicular dentin / 实用口腔医学杂志

Objective:To evaluate the effect of epigallocatechin-3-gallate (EGCG) and epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG-3Me) on the anti-bacterial effect and the stability of intraradicular dentin-adhesive interface.Methods:EGCG and EGCG3Me with the concentration of 400 μg/ml were incorporated into Single Bond 2 (SB2) respectively to obtain 2 modified adhesives E-SB2 and E3-SB2.Confocal laser scanning microscopy(CLSM) and ultraviolet spectrophotometry were used to evaluate the anti-bacterial effect of the modified adhesives.Micro-Raman spectrum was used to test the degree of conversion (DC) of the adhesives.Push-out bond strength test was conducted to examine the immediate bond strength and the bond strength after themocycling.Results:E-SB2 and E3-SB2 both showed inhibiting effect on the proliferation of E.faecalis,while E3-SB2 performed stronger inhibiting effect.DC and the immediate push-out bond strength of SB2 were not decreased with the incorporation of EGCG or EGCG-3Me(P ＞ 0.05).E-SB2 and E3-SB2 showed significantly higher push-out bond strengths than that of SB2 (P ＜ 0.05) after themocycling.Conclusion:EGCG and EGCG-3Me modified adhesives have anti-bacterial effect and can enhance the stability of bonding between intraradicular dentin and adhesive,EGCG-3Me may have stronger anti-bacterial effect.

Quality evaluation of Terminalia billerica based on HPLC fingerprint and multi-components simultaneous determination / 中草药

Objective: To establish the HPLC fingerprint and to determin gallic acid, methyl gallate, corilagin, and ellagic acid in Terminalia billerica, in order to provide the scientific foundation for quality control of T. billerica. Methods: The analysis was performed on Atlantic T3 (250 mm × 4.6 mm, 5 μm) C18 column, mobile phase was acetonitrile-0.2% glacial acetic acid aqueous solution with gradient elution, flow rate was 1.0 mL/min, injection size was 20 μL column, and temperature was maintained at 30 oC. The common mode of T. billerica HPLC fingerprint was established, the hidden information was analyzed in the fingerprint by Chemometrics, and the components in T. billerica by HPLC-MSn and quantitative analysis characteristic peaks were identified. Results: There were 21 common peaks in the diagram and the similarity of the fingerprints was over 0.9 in all 11 batches. The information of the 18 common peaks in T. billerica was summarized by HPLC-MSn technology. The samples were broadly divided into three kinds by principal component analysis and clustering analysis. The five key compounds were verified by partial least squares discriminant analysis method in quantitative analysis, and identified that the No.12 peak was chabulagic acid, and the average recoveries were in the range of 97.24%-98.58%. Conclusion: The HPLC fingerprint method and content determination method are reliable, accurate, rapid, simple, and reproducible, and this study could control the quality of T. billerica.

Screening and evaluation of the active substance of gallnut against oral cavity pathogens / 实用口腔医学杂志

Objective:To study the effects of 3 extracts from Chinese gall on the growth and metabolism of 6 kinds of oral bacteria.Methods:Through a series of extraction and purification,3 active monomer,gallnut extract gallic acid,methyl gallate and gallic acid ethyl ester were selected.Streptococcus mutansUA159(UA159),Actinomyces viscosus (Av),Porphyromonas gingivalis (Pg),Enterococcus faecalis (Ef),Fusobacterium nucleatum(Fn) and Candida albicans (Ca) were treated by the extracts respectively,The growth and metabolism of the becteria were studied by liguid dilution method.Results:The MIC(mg/ml) of Gallic acid anainst the bacteria was 2.5-5,methyl gallate 2.0-4.0 and gallic acid ethyl ester 1.25-2.5.The extracts at 1 mg/ml could inhibit the growth,acid production and extracellular polysaccharides of the 6 oral pathogens.And ethyl gallate showed the strongest effects.Conclusion:Gallic acid and methyl gallate and ethyl gallate at low concentration may inhibit the growth,acid metabolism and glucose metabolism of oral bacteria.

Antimicrobial Activity of Methyl Gallate isolated from the Leaves of Glochidion superbum Against Hospital Isolates of Methicillin Resistant Staphylococcus aureus

An antimicrobial compound has been isolated from the leaves of Glochidion superbum. The compound was determined as methyl 3, 4, 5-trihydroxybenzoate (methyl gallate), based on ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR) and mass spectroscopy (MS) analysis. The isolated compound exhibited potent antimicrobial activity against three clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) by qualitative agar disc diffusion method and quantitative broth dilution method. Agar disc diffusion was done in a dose-dependent manner for each bacterial isolate at disc potencies of 25, 50, 100, and 150 µg/disc. The zones of inhibition were on average equal to 12.27, 14.20, 15.43, and 24.17 mm respectively. The inhibition zones were compared with that of vancomycin disc at 30 µg as a reference standard. The MIC and MBC values were 50 µg/mL and 100 µg/mL respectively. The results of anti MRSA activity were analyzed using one-way ANOVA with Turkey's HSD and Duncan test. In conclusion, methyl gallate which was isolated from G. superbum showed the inhibition activity against methicillin resistant S. aureus.

Immunotherapy with methyl gallate, an inhibitor of Treg cell migration, enhances the anti-cancer effect of cisplatin therapy

Foxp3+ CD25+CD4+ regulatory T (Treg) cells are crucial for the maintenance of immunological self-tolerance and are abundant in tumors. Most of these cells are chemo-attracted to tumor tissues and suppress anti-tumor responses inside the tumor. Currently, several cancer immunotherapies targeting Treg cells are being clinically tested. Cisplatin is one of the most potent chemotherapy drugs widely used for cancer treatment. While cisplatin is a powerful drug for the treatment of multiple cancers, there are obstacles that limit its use, such as renal dysfunction and the development of cisplatin-resistant cancer cells after its use. To minimize these barriers, combinatorial therapies of cisplatin with other drugs have been developed and have proven to be more effective to treat cancer. In the present study, we evaluated the eff ect of the combination therapy using methyl gallate with cisplatin in EL4 murine lymphoma bearing C57BL/6 mice. The combinatorial therapy of methyl gallate and cisplatin showed stronger anti-cancer eff ects than methyl gallate or cisplatin as single treatments. In Treg cell-depleted mice, however, the eff ect of methyl gallate vanished. It was found that methyl gallate treatment inhibited Treg cell migration into the tumor regardless of cisplatin treatment. Additionally, in both the normal and cisplatin-treated tumor-bearing mice, there was no renal toxicity attributed to methyl gallate treatment. These findings suggest that methyl gallate treatment could be useful as an adjuvant method accompanied with cisplatin therapy.

Cytotoxic Effects of Gallic Acid and its Derivatives Against HIV-I-infected Microglia

In the previous study, we found that flavonoids and ginsenosides exhibited high eliminate rates of human immunodeficiency virus type 1 (HIV-1) D3-transfected macrophages. Based on these findings, here we synthesized the derivatives of gallic acid, including methyl gallate, methyl 4-O-methyl gallate, methyl 3,4-O-dimethyl gallate, and methyl 3,4,5-O-trimethyl gallate and measured their cellular toxic effects against HIV-1-infected macrophages. Of these, treatment with methyl 4-O-methyl gallate in the presence of lipopolysaccharide (LPS) and cycloheximide (CHX) most effectively eliminated HIV-1-transfected cytoprotective human microglial CHME5 cells and HIV-1-D3-infected human primary macrophages. Furthermore, these strongly inhibited LPS/CHX-induced phosphorylation of phosphoinositide 3-kinase (PI3K), pyruvate dehydrogenase lipoamide kinase isozyme 1 (PDK1), Akt, and glycogen synthase kinase-3β (GSK-3β) in the Tat-transfected cells and HIV-1-D3-infected human primary macrophages. These findings suggest that methyl 4-O-methyl gallate may be a promising candidate for eliminating HIV-1 infected macrophages by blocking PI3K/Akt signaling pathway.

Simultaneous determination of gallic acid, methyl gallate and ellagic acid in gall of Quercus infectoria Olivier by HPLC / 国际药学研究杂志

Objective To dertermine the content of gallic acid, methyl gallate and ellagic acid in galls of Quercus infectoria Olivier from different batches by HPLC. Methods The chromatogram colume was Agilent Zorbax SB-C18 (4.6 mm x 250 mm, 5 μm), gradiently eluting with methanol as mobile phase A and 0.01% phosphoric acid as B at a flow rate of 1 ml/min. The injection volumn was 5 μl. Detection wavelength was at 258 nm. Results Gallic acid was linear in the range of 0.0318-0.1871 g/L with correlation coefficient of 0.9994. The average recovery was 97.52% with RSD 1.41%. Methyl gallate was linear in the range of 0.0769-0.4612 g/L with correlation coefficient of 0.9994. The average recovery was 99.15% with RSD at 1.46%. Ellagic acid was linear in the range of 0.0158-0.0553 g/L with correlation coefficient of 0.9998. The average recovery was 102.75% with RSD at 0.87%. Conclusion The method is convenient, fast, accurate and practicable, and can be used for controling the quality of the galls of Q. infectoria.

Simultaneous quantitative determination of six active compounds from Paeoniae Rubra Radix and Paeoniae Alba Radix by HPLC / 中草药

Objective: A high performance liquid chromatographic method was established to simultaneously quantify the gallic acid, methyl gallate, albiflorin, paeoniflorin, 1,2,3,4,6-O-pentagalloylglucose, benzoylpaeoniflorin of red peony root, and white peony root. Methods: The content of six components from 32 batches of samples collected from different product areas and markets was determined and compared by means of this established method. The mobile phase comprised of acetonitrile and water containing 0.1% phosphoric acid. Flow rate was 0.8 mL/min and column temperature was 30℃. Chromatography was monitored at 230 and 270 nm. Results: The correlation coefficients between concentration and chromatographic peak area of gallic acid, methyl gallate, albiflorin, paeoniflorin, 1,2,3,4,6-O-pentagalloylglucose, and benzoylpaeoniflorin, respectively were over 0.9999 in the ranges of 0.7830-50.10, 1.094-70.00, 2.367-151.5, 7.823-500.6, 3.125-200.0, and 0.3480-22.25 μg/mL. The average recoveries of the six compounds were 102.1%, 98.88%, 99.25%, 100.4%, 104.2%, and 100.6%, respectively. Conclusion: All the contents of albiflorin, 1,2,3,4,6-O-pentagalloylglucose, gallic acid, and methyl gallate show a remarkable difference between Paeoniae Rubra Radix and Paeoniae Alba Radix. And the latter usually contains more monoterpene glycosides than the former dose except paeoniflorin. On the other hand, Paeoniae Rubra Radix, especially originating from Paeoniae veitchii always contains more polyphenols than Paeoniae Alba Radix dose.

Simultaneous determination of gallic acid, methyl gallate and ellagic acid in gall of Quercus infectoria Olivier by HPLC / 国际药学研究杂志

Objective To dertermine the content of gallic acid, methyl gallate and ellagic acid in galls of Quercus infectoria Olivier from different batches by HPLC. Methods The chromatogram colume was Agilent Zorbax SB-C18(4.6 mm × 250 mm, 5μm), gradiently eluting with methanol as mobile phase A and 0.01%phosphoric acid as B at a flow rate of 1 ml/min. The injection Volume was 5 μl. Detection wavelength was at 258 nm. Results Gallic acid was linear in the range of 0.0318-0.1871 g/L with correlation coefficient of 0.9994. The average recovery was 97.52%with RSD 1.41%. Methyl gallate was linear in the range of 0.0769-0.4612 g/L with correlation coefficient of 0.9994. The average recovery was 99.15% with RSD at 1.46%. Ellagic acid was linear in the range of 0.0158-0.0553 g/L with correlation coefficient of 0.9998. The average recovery was 102.75% with RSD at 0.87%. Conclusion The method is convenient, fast, accurate and practicable, and can be used for controling the quality of the galls of Q. infectoria.

Anti-Depressant Like Effect of Methyl Gallate Isolated from Acer barbinerve in Mice

In the present study, the anti-depressant like effect of methyl gallate (MG) isolated from the stem bark of Acer barbinerve was examined in ICR mice. Body weight (BDW) and blood glucose (BDG) levels significantly decreased in the repeated restraint stress (RRS) group (2 h/day for 14 days) compared to the no stress (NS) group. To examine the effect of MG on RS-induced BDW loss and hypoglycemia, MG (10 mg/kg) and the anti-depressant fluoxetine (10 mg/kg) were administered daily for 14 days. Orally administered MG and fluoxetine significantly attenuated the RS-induced BDW loss and hypoglycemia. Interestingly, MG administered mice showed increased BDG levels in the normal and glucose feeding condition. Chronic RS-subjected mice showed immobilized and depressed behaviors. The effect of MG on the depressed behaviors was evaluated using the tail-suspension test (TST) and the forced swimming test (FST). In both tests, RS-induced immobilized behaviors were significantly reversed in MG and fluoxetine administered groups. Taken together, MG significantly attenuated the RS-induced BDW loss, hypoglycemia, and depressed behaviors. Considering that decreased BDG levels (hypoglycemia) can cause depression, MG may exert its anti-depressant like effect by preventing hypoglycemia. Our results suggest that MG isolated from A. barbinerve can exert anti-depressant like effect, and could be used as a new and natural anti-depressant therapy.

Methyl gallate and chemicals structurally related tomethyl gallate protect human umbilical vein endothelial cells from oxidative stress

Methyl gallate (meGAL) is known as one of major antioxidants. To investigate whether meGAL protects human cells from oxidative stress, meGAL extracted from Korean medicinal plant, Cercis chinensis leaves, was primarily screened using cell viability assay against oxidative stress. Human umbilical vein endothelial cells (HUVECs) were treated with three different concentrations of meGAL for indicated time. After or during meGAL treatment, H2O2 was added and incubated. meGAL showed free radical scavenging effect at low concentration (0.02 mM) and cell protective effect against H2O2-mediated oxidative stress. meGAL recovered viability of HUVECs damaged by H2O2-treatment, reduced the lipid peroxidation (LPO) and decreased the internal reactive oxygen species (ROS) level elevated by H2O2-treatment. Free radical scavenging effect of meGAL was proven to be very high. Differential display reverse transcription-PCR analysis showed that meGAL upregulated the levels of regulator of chromatin condensation 1, type 1 sigma receptor and phosphate carrier protein expressions, respectively. Based on structural similarity compared with meGAL, 14 chemicals were chosen and viability assay was performed. Four chemicals, haematommic acid (56.2% enhancement of viability), gallic acid (35.0%), methylorsellinic acid (23.7%), and syringic acid (20.8%), enhanced more potent cell viability than meGAL, which showed only 18.1% enhancement of cell viability. These results suggest that meGAL and four meGAL-related chemicals protect HUVECs from oxidative stress.

Substâncias isoladas das folhas de Bauhinia microstachya (Raddi) Macbr. (Caesalpiniaceae) / Substances isolated from Bauhinia microstachya (Raddi) Macbr. Caesalpiniaceae) leaves

Neste trabalho é relatado o isolamento de três substâncias das folhas de Bauhinia microstachya (Raddi) Macbr., Caesalpiniaceae, incluindo dois constituintes isolados pela primeira vez nesta espécie, a vitexina e o hidrocarboneto hexatriacontano. As estruturas desses compostos foram estabelecidas através de estudos de RMN- 1H 1D, 2D e EM.

It is reported the isolation of three compounds from leaves of Bauhinia microstachya (Raddi) Macbr., Caesalpiniaceae, including two new constituents in this species, vitexin and the hydrocarbon hexatriacontane. Their structures were established by extensive 1D and 2D 1H NMR and MS spectral studies.