Methyl gallate attenuates virulence and decreases antibiotic resistance in extensively drug-resistant Pseudomonasaeruginosa.

Pseudomonas aeruginosa infections have become a serious threat to public health due to the increasing emergence of extensively antibiotic-resistant strains and high mortality rates. Therefore, the search for new therapeutic alternatives has become crucial. In this study, the antivirulence and antibacterial activity of methyl gallate was evaluated against six clinical isolates of extensively antibiotic-resistant P. aeruginosa. Methyl gallate exhibited minimal inhibitory concentrations of 256-384 µg/mL; moreover, the use of subinhibitory concentrations of the compound inhibited biofilm formation, swimming, swarming, proteolytic activity, and pyocyanin production. Methyl gallate plus antipseudomonal antibiotics showed a synergistic effect by reduced the MICs of ceftazidime, gentamicin and meropenem. Furthermore, the potential therapeutic effect of methyl gallate was demonstrated in an infection model. This study evidenced the antivirulence and antimicrobial activity of methyl gallate as a therapeutic alternative against P. aeruginosa.

Methyl gallate from Camellia nitidissima Chi flowers reduces quorum sensing related virulence and biofilm formation against Aeromonas hydrophila.

Aeromonas hydrophila, a Gram-negative zoonotic bacterium, causes high mortality in fish farming and immunocompromised patients. This study aimed to extract methyl gallate (MG) from the flowers of Camellia nitidissima Chi and evaluate its potential as a quorum sensing inhibitor (QSI) against Aeromonas hydrophila SHAe 115. MG reduced QS-associated virulence factors, including hemolysis, protease, and lipase, while impairing swimming motility and biofilm formation. Additionally, MG down-regulated positive regulatory genes (ahyR, fleQ) and up-regulated negative regulators (litR, fleN). This highlights MG's promise as a potent QSI for A. hydrophila SHAe 115, advancing strategies against infections in aquaculture and human health.

Biosensor-based active ingredient recognition system for screening potential small molecular Severe acute respiratory syndrome coronavirus 2 entry blockers targeting the spike protein from Rugosa rose.

The traditional formulation Hanchuan zupa granules (HCZPs) have been widely used for controlling coronavirus disease 2019 (COVID-19). However, its active components remain unknown. Here, HCZP components targeting the spike receptor-binding domain (S-RBD) of SARS-CoV-2 were investigated using a surface plasmon resonance (SPR) biosensor-based active ingredient recognition system (SPR-AIRS). Recombinant S-RBD proteins were immobilized on the SPR chip by amine coupling for the prescreening of nine HCZP medicinal herbs. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) identified gallic acid (GA) and methyl gallate (MG) from Rosa rugosa as S-RBD ligands, with KD values of 2.69 and 0.95 µM, respectively, as shown by SPR. Molecular dynamics indicated that GA formed hydrogen bonds with G496, N501, and Y505 of S-RBD, and MG with G496 and Y505, inhibiting S-RBD binding to angiotensin-converting enzyme 2 (ACE2). SPR-based competition analysis verified that both compounds blocked S-RBD and ACE2 binding, and SPR demonstrated that GA and MG bound to ACE2 (KD = 5.10 and 4.05 µM, respectively), suggesting that they blocked the receptor and neutralized SARS-CoV-2. Infection with SARS-CoV-2 pseudovirus showed that GA and MG suppressed viral entry into 293T-ACE2 cells. These S-RBD inhibitors have potential for drug design, while the findings provide a reference on HCZP composition and its use for treating COVID-19.

Methyl gallate: Review of pharmacological activity.

Methyl gallate (MG) is a polyphenolic compound widely found in natural plants. MG has been shown to have a variety of biological functions, including anti-tumor, anti-inflammatory, anti-oxidant, neuroprotective, hepatoprotective and anti-microbial activities, and has broad research and development prospects. A total of 88 articles related to MG were searched using the PubMed, Science Direct, and Google Scholar databases, systematically investigating the pharmacological activity and molecular mechanisms of MG. There were no restrictions on the publication years, and the last search was conducted on June 5, 2023. MG can exert pharmacological effects through multiple pathways and targets, such as PI3K/Akt, ERK1/2, Caspase, AMPK/NF-κB, Wnt/ß-catenin, TLR4/NF-κB, MAPK, p53, NLRP3, ROS, EMT. According to the literature, MG has the potential to be a prospective adjuvant for anticancer therapy and deserves further study.

Natural Gallic Acid and Methyl Gallate Induces Apoptosis in Hela Cells through Regulation of Intrinsic and Extrinsic Protein Expression.

Induction of apoptosis is one of the targeted approaches in cancer therapies. As previously reported, natural products can induce apoptosis in in vitro cancer treatments. However, the underlying mechanisms of cancer cell death are poorly understood. The present study aimed to elucidate cell death mechanisms of gallic acid (GA) and methyl gallate (MG) from Quercus infectoria toward human cervical cancer cell lines (HeLa). The antiproliferative activity of GA and MG was characterised by an inhibitory concentration using 50% cell populations (IC50) by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. Cervical cancer cells, HeLa, were treated with GA and MG for 72 h and calculated for IC50 values. The IC50 concentration of both compounds was used to elucidate the apoptotic mechanism using acridine orange/propidium iodide (AO/PI) staining, cell cycle analysis, the Annexin-V FITC dual staining assay, apoptotic proteins expressions (p53, Bax and Bcl-2) and caspase activation analysis. GA and MG inhibited the growth of HeLa cells with an IC50 value of 10.00 ± 0.67 µg/mL and 11.00 ± 0.58 µg/mL, respectively. AO/PI staining revealed incremental apoptotic cells. Cell cycle analysis revealed an accumulation of cells at the sub-G1 phase. The Annexin-V FITC assay showed that cell populations shifted from the viable to apoptotic quadrant. Moreover, p53 and Bax were upregulated, whereas Bcl-2 was markedly downregulated. Activation of caspase 8 and 9 showed an ultimate apoptotic event in HeLa cells treated with GA and MG. In conclusion, GA and MG significantly inhibited HeLa cell growth through apoptosis induction by the activation of the cell death mechanism via extrinsic and extrinsic pathways.

Vachellia farnesiana Pods or a Polyphenolic Extract Derived from Them Exert Immunomodulatory, Metabolic, Renoprotective, and Prebiotic Effects in Mice Fed a High-Fat Diet.

Obesity causes systemic inflammation, hepatic and renal damage, as well as gut microbiota dysbiosis. Alternative vegetable sources rich in polyphenols are known to prevent or delay the progression of metabolic abnormalities during obesity. Vachellia farnesiana (VF) is a potent source of polyphenols with antioxidant and anti-inflammatory activities with potential anti-obesity effects. We performed an in vivo preventive or an interventional experimental study in mice and in vitro experiments with different cell types. In the preventive study, male C57BL/6 mice were fed with a Control diet, a high-fat diet, or a high-fat diet containing either 0.1% methyl gallate, 10% powdered VFP, or 0.5%, 1%, or 2% of a polyphenolic extract (PE) derived from VFP (Vachellia farnesiana pods) for 14 weeks. In the intervention study, two groups of mice were fed for 14 weeks with a high-fat diet and then one switched to a high-fat diet with 10% powdered VFP for ten additional weeks. In the in vitro studies, we evaluated the effect of a VFPE (Vachellia farnesiana polyphenolic extract) on glucose-stimulated insulin secretion in INS-1E cells or of naringenin or methyl gallate on mitochondrial activity in primary hepatocytes and C2C12 myotubes. VFP or a VFPE increased whole-body energy expenditure and mitochondrial activity in skeletal muscle; prevented insulin resistance, hepatic steatosis, and kidney damage; exerted immunomodulatory effects; and reshaped fecal gut microbiota composition in mice fed a high-fat diet. VFPE decreased insulin secretion in INS-1E cells, and its isolated compounds naringenin and methyl gallate increased mitochondrial activity in primary hepatocytes and C2C12 myotubes. In conclusion VFP or a VFPE prevented systemic inflammation, insulin resistance, and hepatic and renal damage in mice fed a high-fat diet associated with increased energy expenditure, improved mitochondrial function, and reduction in insulin secretion.

Methyl Gallate Alleviates Acute Ulcerative Colitis by Modulating Gut Microbiota and Inhibiting TLR4/NF-κB Pathway.

Ulcerative colitis (UC) is a complex immune-mediated inflammatory disease. In recent years, the incidence of UC has increased rapidly, however, its exact etiology and mechanism are still unclear. Based on the definite anti-inflammatory and antibacterial activities of Sanguisorba officinalis L., we studied its monomer, methyl gallate (MG). In this study, we employed flow cytometry and detected nitric oxide production, finding MG regulated macrophage polarization and inhibited the expression of proinflammatory cytokines in vitro. MG also exhibited anti-inflammatory activity accompanying with ameliorating body weight loss, improving colon length and histological damage in dextran sulfate sodium-induced UC mice. Meanwhile, transcription sequencing and 16S rRNA sequencing analyzed the key signaling pathways and changes in the gut microbiota of MG for UC treatment, proving that MG could alleviate inflammation by regulating the TLR4/NF-κB pathway in vivo and in vitro. Additionally, MG altered the diversity and composition of the gut microbiota and changed the abundance of metabolic products. In conclusion, our results are the first to demonstrate that MG has obvious therapeutic effects against acute UC, which is related to macrophage polarization, improved intestinal flora dysbiosis and inhibition of TLR4/NF-κB signaling pathway, and MG may be a promising therapeutic agent for UC treatment.

Protective effect of methyl gallate on murine antigen-induced arthritis by inhibiting inflammatory process and bone erosion.

Methyl gallate (MG) is a plant-derived phenolic compound known to present remarkable anti-inflammatory effect in different experimental models, such as paw oedema, pleurisy, zymosan-induced arthritis and colitis. Herein we investigated the effect of MG in the mice model of antigen-induced arthritis (AIA), a model with complex inflammatory response, driven primally by immune process and that cause bone and cartilage erosion similarly found in rheumatoid arthritis. Arthritis was induced by intra-articular injection of albumin methylated from bovine serum (mBSA) in C57BL/6 male mice previously immunized. The dose-response analysis of MG (0.7-70 mg/kg; p.o) showed that maximum inhibition was reached with the dose of 7 mg/kg on paw oedema and cell infiltration induced by AIA at 7 h. Treatment with MG (7 mg/kg; p.o) or with the positive control, dexamethasone (Dexa, 10 mg/kg, ip) reduced AIA oedema formation, leukocyte infiltration, release of extracellular DNA and cytokine production 7 and 24 h (acute response). Mice treated daily with MG for 7 days showed no significant weight loss or liver and kidney toxicity contrary to dexamethasone that induced some degree of toxicity. Prolonged treatment with MG inhibited the late inflammatory response (28 days) reducing oedema formation, cell infiltration, synovial hyperplasia, pannus formation and cartilage degradation as observed in histopathological analyses. Ultimately, MG reduced bone resorption as evidenced by a decrease in tartrate-resistant acid phosphate (TRAP)-positive cells number in femur histology. Altogether, we demonstrate that MG ameliorates the inflammatory reaction driven primarily by the immune process, suggesting a potential therapeutic application in arthritis treatment.

Effect of methyl gallate on immune response of Biomphalaria alexandrina (Ehrenberg, 1831) snails to infection with Schistosoma mansoni (Sambon, 1907).

Schistosomiasis still affects a lot of people in many developing countries. Reducing the disease dissemination has been the target of various studies. As methyl gallate has antioxidant properties, it is assumed that it can be a good candidate for stimulating the immune response of snails. So, the aim of this work is to investigate the potential of using methyl gallate as an immunostimulant to Biomphalaria alexandrina snails in order to prevent the development of invading miracidia into infective cercariae. The infected snails were exposed to three concentrations of methyl gallate for two periods: 24 and 72 h. The results indicated that the most effective concentration was the lowest one: 125 mg/L of methyl gallate for 72 h, as it reduced both infection rate and mean number of shed cercariae. Also, it increased the total number of snails' hemocytes in hemolymph, which were observed in head-foot region and digestive gland of treated snails surrounding degenerated sporocysts and cercariae. In addition, hydrogen peroxide showed its highest content in tissues of snails exposed to 125 mg/L of methyl gallate for 72 h. In conclusion, methyl gallate can be considered as one of the most promising immunostimulants of B. alexandrina snails against infection with Schistosoma mansoni.

Methyl gallate attenuates inflammation induced by Toll-like receptor ligands by inhibiting MAPK and NF-Κb signaling pathways.

OBJECTIVE AND DESIGN: Methyl gallate (MG) is a prevalent polyphenol in the plant kingdom, which may be related to the effects of several medicinal plants. Although it is widely reported that polyphenols have therapeutic effects, there are few studies demonstrating that MG has anti-inflammatory action. This study aimed to investigate the molecular mechanism behind the anti-inflammatory activity of MG and its effect on hyperalgesia. METHODS: Swiss mice were pretreated orally with different doses of MG and subjected to i.pl. injection of zymosan to induce paw edema. RAW264.7 macrophages and BMDMs stimulated with different TLR agonists such as zymosan, LPS, or Pam3CSK4 were used to investigate the molecular mechanisms of MG RESULTS: MG inhibits zymosan-induced paw edema and hyperalgesia and modulates molecular pathways crucial for inflammation development. Pretreatment with MG inhibited cytokines production and NF-κB activity by RAW 264.7 cells stimulated with zymosan, Pam3CSK4 or LPS, but not with PMA. Moreover, pretreatment with MG decreased IκB degradation, nuclear translocation of NF-κBp65, c-jun and c-fos and ERK1/2, p38 and JNK phosphorylation. CONCLUSION: Thus, the results of this study demonstrate that MG has a promising anti-inflammatory effect and suggests an explanation of its mechanism of action through the inhibition of NF-κB signaling and the MAPK pathway.

Metabolism of Gallic Acid and Its Distributions in Tea (Camellia sinensis) Plants at the Tissue and Subcellular Levels.

In tea (Camellia sinensis) plants, polyphenols are the representative metabolites and play important roles during their growth. Among tea polyphenols, catechins are extensively studied, while very little attention has been paid to other polyphenols such as gallic acid (GA) that occur in tea leaves with relatively high content. In this study, GA was able to be transformed into methyl gallate (MG), suggesting that GA is not only a precursor of catechins, but also can be transformed into other metabolites in tea plants. GA content in tea leaves was higher than MG content-regardless of the cultivar, plucking month or leaf position. These two metabolites occurred with higher amounts in tender leaves. Using nonaqueous fractionation techniques, it was found that GA and MG were abundantly accumulated in peroxisome. In addition, GA and MG were found to have strong antifungal activity against two main tea plant diseases, Colletotrichum camelliae and Pseudopestalotiopsis camelliae-sinensis. The information will advance our understanding on formation and biologic functions of polyphenols in tea plants and also provide a good reference for studying in vivo occurrence of specialized metabolites in economic plants.

Antibacterial activity of compounds isolated from Caesalpinia coriaria (Jacq) Willd against important bacteria in public health.

Antimicrobial resistance has been increasing in recent years and is most frequently found in pathogenic microorganisms resistant or multiresistant to drugs. The secondary metabolites of plants have been evaluated as alternatives for control and treatment of these microorganisms. The aim of this study was to isolate and identify the secondary metabolites with antibacterial activity from Caesalpinia coriaria (Jacq) Willd fruit. Hydroalcoholic extract (CCHA), was subjected to a bipartition with ethyl acetate giving two fractions an aqueous (Aq-F) and an organic (EtOAc-F). The isolation of bioactive fraction (EtOAc-F) allowed obtain two important compounds, methyl gallate (1) and gallic acid (2). These compounds were identified by high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). The CCHA, both fractions and the isolated compounds were evaluated in vitro to determine their Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Listeria monocytogenes and Staphylococcus aureus. Gallic acid (2) showed the lowest MIC on S. typhi, (0.156 mg/mL), L. monocytogenes and S. aureus (1.25 mg/mL), while methyl gallate (1) had the best inhibitory effect against E. coli and P. aeruginosa (1.25 mg/mL). On the other hand, methyl gallate (1) showed the best MBC on P. aeruginosa (2.50 mg/mL), and gallic acid (2) had the lowest MBC on P. aeruginosa and L. monocytogenes. In conclusion, methyl gallate (1) and gallic acid (2) are the compounds responsible for the antibacterial activity of Caesalpinia coriaria fruit.

In vivo fluid accumulation-inhibitory, anticolonization and anti-inflammatory and in vitro biofilm-inhibitory activities of methyl gallate isolated from Terminalia chebula against fluoroquinolones resistant Vibrio cholerae.

Acute Vibrio cholerae infection triggers significant inflammatory response and immense fluid secretion in the intestine. In the present study, methyl gallate (MG) isolated from Terminalia chebula was evaluated to determine the in vivo fluid accumulation-inhibitory, anticolonization and anti-inflammatory and in vitro biofilm-inhibitory activities against multi-drug resistant (MDR) V. cholerae. Bacterial membrane-damaging and biofilm-inhibitory activities were determined by membrane perturbation and transmission electron microscopy (TEM); and microdilution assays, respectively. Fluid accumulation-inhibitory and anticolonization activities of MG (23.80-95.23 mg/kg body weight) were determined in 4-5 days old BALB/c mice with an incubation time of 18 h. The effect of MG (1, 50 and 500 mg/kg body weight) on intestinal inflammatory reaction induced by V. cholerae was studied by performing histology in Swiss albino mice. MIC and MBC of MG against the test strains were 32-64 and 64-256 µg/ml, respectively. MG showed the fluid accumulation-inhibitory activity with inhibition values of 42.86-89.08% at doses between 23.80 and 95.23 mg/kg body weight and significant anticolonization activity (p < 0.0001) against V. choleare in the suckling mouse intestine. MG (500 mg/kg body weight) significantly inhibited the inflammatory reactions induced by V. cholerae compared to the vehicle control. MG exhibited 70% minimum biofilm inhibition concentration of 64 µg/ml and bacterial membrane damaging activity at 1 × MBC. The results obtained in the present study suggest that MG has potential as an effective agent for the treatment of severe secretory and inflammatory diarrheal disease caused by MDR V. cholerae.

Optimization and anti-inflammatory evaluation of methyl gallate derivatives as a myeloid differentiation protein 2 inhibitor.

Myeloid differentiation protein 2 (MD2) is a co-receptor of toll-like receptor 4 (TLR4) responsible for the recognition of lipopolysaccharide (LPS) and mediates a series of TLR4-dependent inflammatory responses in inflammatory lung diseases including acute lung injury (ALI). Targeting MD2 thus may provide a therapeutic strategy against these lung diseases. In this study, we identified a novel compound 4k with the potent anti-inflammatory activity among 39 methyl gallate derivatives (MGDs). MGD 4k exhibited a high binding affinity to MD2, which in turn prevented the formation of the LPS/MD2/TLR4 complex. In addition, MGD 4k significantly reversed the upregulation of LPS-induced inflammatory mediators such as tumor necrosis factor-α, interleukin-6, intracellular adhesion molecule-1, vascular cell adhesion molecule-1, and monocyte chemoattractant protein-1 in vitro and in vivo. Mechanistically, MGD 4k performed anti-inflammatory function by inactivating JNK, ERK and p38 signaling pathways. Taken together, our study identified MGD 4k as a novel potential therapeutic agent for ALI through inhibiting MD2, inflammatory responses, and major inflammation-associated signaling pathways.

Galloyl derivatives from Caesalpinia coriaria exhibit in vitro ovicidal activity against cattle gastrointestinal parasitic nematodes.

Gastrointestinal nematodes (GIN) are responsible for enormous economic losses worldwide. The use of anthelmintic drugs reduces the parasitic burden in ruminants. However, the excessive use of these drugs triggers anthelmintic resistance in these parasites, which leads to a worrisome inefficacy of most of the commercially available antiparasitic drugs. Caesalpinia coriaria is an arboreal legume possessing medical properties, although the antiparasitic potential of this plant against animal parasitic nematodes has not yet been studied. The aim of this study was to assess the in vitro ovicidal activity of a hydro-alcoholic extract (HA-E) from C. coriaria fruits against GIN and to identify the compounds responsible for this activity through an egg hatch inhibition (EHI) assay. GIN eggs obtained from cattle faeces were used in bio-guided assays. The HA-E was subjected to a liquid-liquid extraction using water and ethyl acetate to obtain two fractions, an organic fraction (EtOAc-F, 27% yield) and an aqueous (Aq-F, 73% yield) fraction. The chromatographic fractionation of the EtOAc-F (2 gr) was performed on a glass column packed with silica gel and eluted with dichloromethane/methanol with 10% ascending polarity. The bioactive compounds were analysed using high-performance liquid chromatography (HPLC) with UV detection, nuclear magnetic resonance (NMR) spectroscopy and mass spectroscopy (MS). The HA-E extract and the EtOAc-F showed ovicidal activity at a LC50 of 0.92 and 0.16 mg/mL, respectively. A concentration-dependant effect was observed in both treatments. Chromatographic fractionation of the EtOAc-F, allowed for the isolation and characterisation of three important compounds: methyl gallate (1), gallic acid (2) and an unidentified compound (UC). The bioactive molecules (2 and UC) displayed an ovicidal activity close to 100% at 1 mg/mL concentration. The results of this work show that gallic acid (2) isolated from C. coriaria fruits is responsible for its ovicidal activity. The use of Caesalpinia coriaria could be explored in future studies as an environmentally-friendly alternative for the control of GIN in ruminants.

Antioxidant and Cytoprotective Effects of (-)-Epigallocatechin-3-(3″-O-methyl) Gallate.

Reactive oxygen species (ROS) are generated from diverse cellular processes or external sources such as chemicals, pollutants, or ultraviolet (UV) irradiation. Accumulation of radicals causes cell damage that can result in degenerative diseases. Antioxidants remove radicals by eliminating unpaired electrons from other molecules. In skin health, antioxidants are essential to protect cells from the environment and prevent skin aging. (-)-Epigallocatechin-3-(3″-O-methyl) gallate (3″Me-EGCG) has been found in limited oolong teas or green teas with distinctive methylated form, but its precise activities have not been fully elucidated. In this study, we examined the antioxidant roles of 3″Me-EGCG in keratinocytes (HaCaT cells). 3″Me-EGCG showed scavenging effects in cell and cell-free systems. Under H2O2 exposure, 3″Me-EGCG recovered cell viability and increased the expression of heme oxygenase 1 (HO-1). Under ultraviolet B (UVB) and sodium nitroprusside (SNP) exposure, 3″Me-EGCG protected keratinocytes and regulated the survival protein AKT1. By regulating the AKT1/NF-κB pathway, 3″Me-EGCG augmented cell survival and proliferation in HaCaT cells. These results indicate that 3″Me-EGCG exhibits antioxidant properties, resulting in cytoprotection against various external stimuli. In conclusion, our findings suggest that 3″Me-EGCG can be used as an ingredient of cosmetic products or health supplements.

Root Bark of Paeonia suffruticosa Extract and Its Component Methyl Gallate Possess Peroxynitrite Scavenging Activity and Anti-inflammatory Properties through NF-κB Inhibition in LPS-treated Mice.

A peroxynitrite (ONOO-)-generating system induced by 3-morpholinosydnonimine, was used to evaluate the ONOO- scavenging properties of plants that have been widely used as traditional medicine in Korea for the treatment of several diseases. The most effective medicinal plants were Paeonia suffruticosa Andrew, followed in order by Lonicera japonica Thunb., Curcuma zedoaria (Christm.) Roscoe, and Pueraria thunbergiana Benth. In addition, root bark of P. suffruticosa was partitioned with organic solvents of different polarities, and the ethyl acetate (EtOAc) fraction showed the strongest ONOO- scavenging activity. Methyl gallate, a plant-derived phenolic compound identified from the EtOAc fraction, exerted strong ONOO- scavenging activity. The in vivo therapeutic potential of methyl gallate was investigated using lipopolysaccharide-treated mice. Oral administration of methyl gallate protected against acute renal injury and exhibited potential anti-inflammatory properties through an increase in antioxidant activity and decrease in nuclear factor-kappa B activity.

Isolation and Purification of Bioactive Compounds from the Stem Bark of Jatropha podagrica.

This paper reports the successive isolation and purification of bioactive compounds from the stem bark of Jatropha podagrica, a widely known medicinal plant. The ethyl acetate extract of the stem bark exhibited the strongest antioxidant activity assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP) assays (IC50 = 46.7, 66.0, and 492.6, respectively). By column chromatography (CC) with elution of hexane and ethyl acetate at 8:2, 7:3, and 6:4 ratios, the isolation of this active extract yielded five fractions (C1⁻C5). Chemical structures of the constituents included in C1⁻C5 were elucidated by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) and resolved as methyl gallate (C1, C2, C3, C4), gallic acid (C1, C2), fraxetin (C2, C3, C4, C5), and tomentin (C3). Mixture C2 (IC50 DPPH and ABTS = 2.5 µg/mL) and C3 (IC50 FRAP = 381 µg/mL) showed the highest antioxidant properties. Among the isolated fractions, C4 was the most potential agent in growth inhibition of six bacterial strains including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Bacillus subtilis, and Proteus mirabilis (MIC = 5, 20, 30, 20, 25, and 20 mg/mL, respectively). All identified constituents exerted an inhibitory activity on the growth of Lactuca sativa, of which the mixture C3 performed the maximal inhibition on shoot (IC50 = 49.4 µg/mL) and root (IC50 = 47.1 µg/mL) growth. Findings of this study suggest that gallic acid, methyl gallate, fraxetin, and tomentin isolated from J. podagrica possessed antioxidant, antibacterial, and growth inhibitory potentials.

Designing of enzyme inhibitors based on active site specificity: lessons from methyl gallate and its lipoxygenase inhibitory profile.

Methyl gallate was purified, by lipoxygenase (LOX) inhibitory activity-guided method since its alleged anti-inflammatory property, from Bergenia ligulata (Wall), a plant used in the traditional, Ayurvedic system of medicine extensively. The LOX inhibitory property of methyl gallate was studied by enzyme kinetics, isothermal titration calorimetry and molecular docking followed by molecular simulation studies. The wet-laboratory experiments and in silico studies showed complete agreement, and promise of methyl gallate as a drug-lead molecular scaffold for anti-inflammatory therapy, based on LOX inhibition. The expressed work shows the need of nonactive site binding parameters to be considered while designing of inhibitors based on the specificities toward active sites of enzymes.

Development of functional agricultural products utilizing the new health claim labeling system in Japan.

In April 2015, Consumer Affairs Agency of Japan launched a new food labeling system known as "Foods with Function Claims (FFC)." Under this system, the food industry independently evaluates scientific evidence on foods and describes their functional properties. As of May 23, 2017, 1023 FFC containing 8 fresh foods have been launched. Meanwhile, to clarify the health-promoting effects of agricultural products, National Agriculture and Food Research Organization (NARO) implemented the "Research Project on Development of Agricultural Products" and demonstrated the risk reduction of osteoporosis of ß-cryptoxanthin rich Satsuma mandarins and the anti-allergic effect of the O-methylated catechin rich tea cultivar Benifuuki. These foods were subsequently released as FFC. Moreover, NARO elucidated the health-promoting effects of various functional agricultural products (ß-glucan rich barley, ß-conglycinin rich soybean, quercetin rich onion, etc.) and a healthy boxed lunch. This review focuses on new food labeling system or research examining functional aspects of agricultural products.