Benzyl Caffeate Research Articles

Targeting Matrix Metalloproteinase‐3 for Dental Caries Prevention Using Herbal Isolates: MMP3 Inhibition by Cinnamic Acids

Objectives: Dental caries, a prevalent infectious disease affecting teeth, ranks highest among 328 diseases, according to a 2017 Lancet study. In demineralized human dentin, matrix metalloproteinase‐3 (MMP3) functions as a proteoglycanase, contributing to the degradation of proteoglycan components. This process exposes collagen fibrils, thereby facilitating the demineralization of the dentin matrix. Inhibiting MMP3 shows potential for preventing dental caries.Methods: The binding affinity of 20 cinnamic acid derivatives, namely cynarin, chlorogenic acid, rosmarinic acid, cinnamyl caffeate, phenethyl caffeate, N‐p‐coumaroyltyramine, caffeic acid 3‐glucoside, caffeic acid phenethyl ester, roscovitine, benzyl caffeate, o‐coumaric acid, artepillin C, caffeic acid, methyl caffeate, 2‐methylcinnamic acid, ferulic acid, drupanin, p‐coumaric acid, cinnamic acid, and sinapinic acid, to the MMP3 catalytic cleft, was assessed utilizing AutoDock 4.0. Molecular dynamics simulation was then employed to analyze the stability of backbone atoms in free MMP3, MMP3‐positive control inhibitor, and MMP3 complexed with the top‐ranked cinnamic acid over a 100 ns computer simulation.Results: Four cinnamic acids demonstrated ΔGbinding scores below −10 kcal/mol, with cynarin emerging as the most potent MMP3 inhibitor, featuring a ΔGbinding score and inhibition constant value of −15.57 kcal/mol and 3.83 pM, respectively. The MMP3–cynarin complex exhibited stability after a 50 ns computer simulation, showing a root‐mean‐square deviation of 8 Å.Conclusions: The inhibition of MMP3 by cynarin, chlorogenic acid, rosmarinic acid, and cinnamyl caffeate holds promise as a potential preventive strategy for dental caries.

Antiangiogenic and apoptotic effects of benzyl caffeate on human umbilical vein endothelial cells (HUVECs) and chick embryo chorioallantoic membrane (CAM): In vitro and in vivo models

• Benzyl caffeate inhibits the proliferation and tube formation of endothelial cells. • Benzyl caffeate reduces the number of newly formed vessels in chick embryo chorionic membrane models. • Benzyl caffeate induces apoptosis via activation of proapoptotic signaling. • Benzyl caffeate exerts its antiangiogenic effects through induction of endothelial apoptosis. Caffeic acid and its derivatives are polyphenolic compounds, which are present in high concentration in propolis and medicinal plants. Their antioxidant activity has been reported; however, the antiangiogenic effects of benzyl caffeate remain unclear. In this study, we investigated the angiogenic and apoptotic effects of benzyl caffeate both in vitro on HUVECs and in vivo in chick embryo chorionic membrane (CAM) models. Benzyl caffeate significantly inhibited angiogenesis via HUVECs-based tube formation by inducing apoptosis and antiproliferative effects on endothelial cells. Furthermore, benzyl caffeate significantly reduced the number of newly formed vessels in CAM. Western blot analysis showed that benzyl caffeate induced apoptosis via proapototic signaling via activation of caspase-9, caspase-3 and cleavage of PARP and lamin A/C. In addition, western blot showed that benzyl caffeate treatment inhibited c-Raf/MEK/ERK signaling, and thereby suppressed angiogenesis. In conclusion, the results indicate that benzyl caffeate exerts its antiangiogenic effects via induction of endothelial apoptosis.

Allergenic compounds in honey bee products

Allergy can be defined as a strong specific reaction of the human body to exogenous molecules that may occur in the normal environment. Food allergies are individualistic adverse reactions to foods. Food related reactions are individualistic because they affect only a few people in the population: most people can eat the same foods with no reactions. Adverse food reactions can include IgE and non IgE mediated primary immunological sensitivities, food intolerances, a secondary sensitivities. Bee products such as honeybees, honey, royal jelly and pollen are widely consumed as a health supplement. These products are reported in various reports that may cause allergic reactions when consumed. In this study, the allergic effects and allergen components of bee products consumed as food are described. These allergens include high molecular weight proteins in the bee pollen and honey, MRJ1 and MRJ2 in the royal jelly, and 3-methyl-2-butenyl caffeate, phenylethyl caffeate, benzyl caffeate, geranyl caffeate, benzyl alcohol benzyl cinnammate, methyl cinnammate, ferulic acid, tecto chrysin in the propolis

A plant origin of Chinese propolis: Populus canadensis Moench

Honey bees make propolis from resins depending on resinous plants available in a particular environment. The aim of this work was to identify the plant origin of Chinese propolis. Through a combination of phytochemical analysis and behavior observation of worker bees, we find that worker bees collected resin on the bud surface of Populus canadensis Moench, and bud resin of P. canadensis presented high similarities between resin in worker bees’ corbiculae and propolis. The results reveal that P. canadensis, a hybrid variety of Populus nigra L. × Populus deltoides, is a plant origin of Chinese propolis. Characteristic components of Chinese propolis included benzyl caffeate, phenethyl caffeate, cinnamyl caffeate, cinnamyl p-cinnamate, pinobanksin-3-acetate, chrysin, pinocembrin, galangin, 5-methoxy pinobanksin, and pinobanksin. These compounds represented more than 80% of the total phenolic contents. This finding will help evaluate the quality and authenticity of poplar type propolis.

Potential Protective Effects of Bioactive Constituents from Chinese Propolis against Acute Oxidative Stress Induced by Hydrogen Peroxide in Cardiac H9c2 Cells.

Chinese propolis (CP) is known as a health food but its beneficial effects in protecting cardiomyocytes remain elusive. Here, we investigated the effects of CP and its active compounds on hydrogen peroxide (H2O2) induced rats cardiomyocytes (H9c2) oxidative injury. Cell viability decreases induced by H2O2 were mitigated by different CP extracts using various solvents. From these active fractions, six active compounds were separated and identified. Among tested isolated compound, the cytoprotective activities of three caffeates, caffeic acid phenethyl ester (CAPE), benzyl caffeate (BZC), and cinnamyl caffeate (CNC), exerted stronger effects than chrysin, pinobanksin, and 3,4-dimethoxycinnamic acid (DMCA). These three caffeates also increased H9c2 cellular antioxidant potential, decreased intracellular calcium ion ([Ca2+]i) level, and prevented cell apoptosis. Overall, the cardiovascular protective effects of the CP might be attributed to its caffeates constituents (CAPE, BZC, and CNC) and provide evidence for its usage in complementary and alternative medicine.

Chemical characterization and antioxidant properties of Canadian propolis

Propolis is a multifunctional material collected and used by honey bees in the construction and maintenance of their hives. It has been used in folk medicine for centuries. Concentrations of major constituents and antioxidant characteristics of ethanolic extracts of three samples of propolis (EEPs) collected from different geographical locations in Canada (Saskatchewan, Ontario and British Columbia) were determined. Twenty-one compounds were identified in each EEP, of which 18 were polyphenols. Semi-quantitative measurements showed that benzyl caffeate, pinocembrin, sakuranetin and pinobanksin-3-acetate were most abundant in propolis from Ontario. Total phenolic content of EEPs were quantified by using the Folin–Ciocalteu reagent which ranged between 410.81 and 429.61 mg GAE/g EEP. Free radical scavenging activities of propolis were confirmed by use of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and by using Nrf2 Luciferase reporter cell lines. The three EEPs exhibited strong scavenging of free radicals, and protective activity against oxidative stress caused by exposure to H2O2 in this in vitro system. These results support the use of propolis from these regions of Canada as a source of natural antioxidants.

Impact of Biohybrid Magnetite Nanoparticles and Moroccan Propolis on Adherence of Methicillin Resistant Strains of Staphylococcus aureus.

Biofilm bacteria are more resistant to antibiotics than planktonic cells. Propolis possesses antimicrobial activity. Generally, nanoparticles containing heavy metals possess antimicrobial and antibiofilm properties. In this study, the ability of adherence of Methicillin Resistant Strains of Staphylococcus aureus (MRSA) to catheters treated with magnetite nanoparticles (MNPs), produced by three methods and functionalized with oleic acid and a hydro-alcoholic extract of propolis from Morocco, was evaluated. The chemical composition of propolis was established by gas chromatography mass spectrometry (GC-MS), and the fabricated nanostructures characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Mossbauer spectroscopy and Fourrier transform infrared spectroscopy (FTIR). The capacity for impairing biofilm formation was dependent on the strain, as well as on the mode of production of MNPs. The co-precipitation method of MNPs fabrication using Fe3+ and Na2SO3 solution and functionalized with oleic acid and propolis was the most effective in the impairment of adherence of all MRSA strains to catheters (p < 0.001). The adherence of the strain MRSA16 was also significantly lower (p < 0.001) when the catheters were treated with the hybrid MNPs with oleic acid produced by a hydrothermal method. The anti-MRSA observed can be attributed to the presence of benzyl caffeate, pinocembrin, galangin, and isocupressic acid in propolis extract, along with MNPs. However, for MRSA16, the impairment of its adherence on catheters may only be attributed to the hybrid MNPs with oleic acid, since very small amount, if any at all of propolis compounds were added to the MNPs.

Effect of Ethanol/Water Solvents on Phenolic Profiles and Antioxidant Properties of Beijing Propolis Extracts.

Propolis is a natural substance known to be beneficial for human health and used as a folk medicine in many parts of the world. In this study, phenolic profiles and antioxidant properties of Beijing propolis extracted by different ethanol/water solvents were analyzed. Our results reveal that phenolic compounds and antioxidant properties of propolis extracts were significantly dependent on the concentration of ethanol/water solvents. Totally, 29 phenolic compounds were identified: 12 phenolic acids, 13 flavonoids, and 4 phenolic acid esters. In particular, 75 wt.% ethanol/water solvent may be the best for the highest extraction yield and the strongest antioxidant properties. Caffeic acid, benzyl caffeate, phenethyl caffeate, 5-methoxy pinobanksin, pinobanksin, pinocembrin, pinobanksin-3-O-acetate, chrysin, and galangin were the characteristic compounds of Beijing propolis, and these compounds seem to verify that Beijing propolis may be poplar-type propolis. In addition, the presence of high level of pinobanksin-3-O-acetate in Chinese propolis may be a novel finding, representing one-third of all phenolics.

Inhibitory Effects of Caffeic Acid Ester Analogues on Free Radicals and Human Liver Microsome CYP1A2 Activities

Ethyl caffeate (EC), octyl caffeate(OC), benzyl caffeate(BC) and phenethyl caffeate(PC) were synthesized and evaluated for scavenging of superoxide anion, nitric oxide radical and 1,1-diphenyl-1-picrylhydrazyl radical (DPPH). Antioxidant activity was investigated with reducing power method. Pooled human liver microsome was used for investigating the effects on cytochrome P450 1A2 (CYP1A2) catalytic activities by using phenacetin as a substrate. Dixon and Cornish-Bowden plots were used for enzyme kinetic analysis. The EC, OC, BC and PC potentially inhibited superoxide anion, nitric oxide and DPPH radicals. IC(50) values of superoxide anion scavenging of EC, OC, BC and PC were 16.42, 79.83, 123.69 and 123.69 µg/ml, respectively. EC was more potent than OC and BC in terms of nitric oxide radical scavenger: IC(50) values of EC, OC and BC were 24.16, 37.34 and 52.64 µg/ml, respectively. In addition, the IC(50) values of EC, OC, BC and PC on DPPH radical scavenging were 70.00, 184.56, 285.34 and 866.54 µg/ ml, respectively. The IC(50) values of EC, OC, BC and PC on phenacetin O-deethylation were 124.98, 111.86, 156.68 and 31.05 µg/ml, respectively. Enzyme kinetics showed that the type of inhibition mechanism was mixed-type. The result of this study shows that caffeic acid ester analogues potentially scavenge free radicals and inhibit catalytic activity of CYP1A2. This may lead to important implications in the prevention of CYP1A2-mediated chemical carcinogenesis.

Simultaneous Quantification of Eight Major Bioactive Phenolic Compounds in Chinese Propolis by High-Performance Liquid Chromatography

A simple, sensitive and specific high-performance liquid chromatography-UV (HPLC-UV) method has been developed to simultaneously quantify the eight major bioactive phenolic compounds in Chinese propolis, namely caffeic acid, isoferulic acid, 3,4-dimethoxycinnamic acid, pinobanksin 5-methyl ether, pinocembrin, benzyl caffeate, chrysin and galangin. This HPLC assay was performed on an Agilent Zorbax Extend-C18 (250 x 4.6 mm, 5 microm) column with a gradient of methanol and 0.2% aqueous acetic acid (v/v) in 50 min, at a flow rate of 1.0 mL/min, and detected at 290 nm. All calibration curves showed good linearity (r2 > 0.999) within the test ranges. The intra- and inter-day assay precision (RSD) of eight phenolic compounds were in the range of 0.07-4.92%. The recoveries were between 98.3% and 104.8%. This assay was applied to the evaluation of nineteen samples from different origins in China. The results indicated that the developed assay could be readily utilized for the quality control of propolis.

Selective analysis of phenolic compounds in propolis by HPLC‐MS/MS

Phenolic compounds (flavonoids and phenolic acid derivatives) are major active constituents of the resinous fraction of propolis, and also represent its allergenic principles. We have developed a chromatography electrospray ionisation tandem mass spectrometry (HPLC-ESI-MS/MS) method to characterise the polyphenolic fraction of propolis rapidly and quali-quantitatively. With precursor ion scanning, selective detection of caffeic esters was easily achieved, confirming the identification of prenyl caffeate, benzyl caffeate and phenylethyl caffeate by comparison with synthetic standards. The ionisation and fragmentation behaviour of the major propolis flavonoids was rationalised and applied to selected real samples. Taken together, the results of this study show that the introduction of precursor ion analysis leads to a significant improvement in the characterisation of the phenolic fraction of propolis, paving the way to the establishment of a better quality control for this important natural remedy.

Evaluation of the Main Contact Allergens in Propolis (1995 to 2005)

Propolis, the bee glue, is increasingly used in biocosmetics and for the self-treatment of various diseases. Patients reacting to propolis were requested to participate in further testing with the breakdown constituents of the bee glue. Twenty-seven patients agreed to be tested with 18 constituents, including four caffeates (the typical allergens of propolis) derived from the sticky exudates of poplar buds. Seven patients did not react to the propolis constituents tested. In the remaining 20 patients, the four caffeates produced strong reactions. Phenylethyl caffeate, which produced positive reactions in 20 patients, was the leading contact allergen. Benzyl caffeate elicited strong responses in 18 patients, and 3-methyl-2-butenyl caffeate produced reactions in 17 patients. Geranyl caffeate produced positive reactions in 11 patients. The flavonoid tectochrysin gave positive results in 2 patients; ferulic acid, coumaric acid, and methyl cinnamate produced weak responses. In middle Europe, the caffeates are the responsible allergens in propolis allergy. Patients from other countries, where poplar trees do not grow, become allergic to other propolis constituents but not to the caffeates.

Caffeic acid phenethyl ester (CAPE) analogues: potent nitric oxide inhibitors from the Netherlands propolis.

The MeOH and water extracts of the Netherlands propolis were tested for their inhibitory activity toward nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage-like J774.1 cells. Both of the extract possessed significant NO inhibitory activity with IC(50) values of 23.8 and 51.5 microg/ml, respectively. Then 13 phenolic compounds obtained from the MeOH extract showing stronger NO inhibition were examined on their NO inhibitory activities. Caffeic acid phenethyl ester (CAPE) analogues, i.e., benzyl caffeate, CAPE and cinnamyl caffeate, possessed most potent NO inhibitory activities with IC(50) values of 13.8, 7.64 and 9.53 microM, respectively, which were two- to four-fold stronger than the positive control N(G)-monomethyl-L-arginine (L-NMMA; IC(50), 32.9 microM). Further study on the synthetic analogues of CAPE revealed that both of 3-phenylpropyl caffeate (18; IC(50), 7.34 microM) and 4-phenylbutyl caffeate (19; IC(50), 6.77 microM) possessed stronger NO inhibitory activity than CAPE (10) and that elongation of alkyl side chain of alcoholic parts of caffeic acid esters enhance the NO inhibitory activity. In addition, it was found that CAPE analogues having longer carbon chain (>C(5)) in alcoholic part showed toxic effects toward J774.1 cells. This NO inhibitory effect may directly correlate with antiinflammatory properties of the Netherlands propolis.

Constituents of Chinese propolis and their antiproliferative activities.

Two new flavonoids, 3-O-[(S)-2-methylbutyroyl]pinobanksin (1) and 6-cinnamylchrysin (2), were isolated from the EtOAc-soluble fraction of the MeOH extract of Chinese propolis, along with 12 known compounds (3-14). The structures of the isolated compounds were elucidated on the basis of spectroscopic and chemical analyses. The isolated compounds were tested for their antiproliferative activity toward five different cancer cell lines. Benzyl caffeate (13) and phenethyl caffeate (14) showed potent antiproliferative activity toward tested cell lines with a selective activity toward colon 26-L5 carcinoma cell line (EC(50) values: 13, 1.01; 14, 0.30 microM).

Benzyl Caffeate, an Antioxidative Compound Isolated from Propolis

(1992). Benzyl Caffeate, an Antioxidative Compound Isolated from Propolis. Bioscience, Biotechnology, and Biochemistry: Vol. 56, No. 8, pp. 1321-1322.

New Phenolics from Baccharis Leaf Exudate

Several lipophilic phenolics were found in leaf resins of Baccharis species, reported earlier to produce terpenoids and flavonoid aglycones. They were identified by NMR and GC/MS studies, respectively. The structure of 2′,4′β-trihydroxy-6′-methoxychalcone from B. salicifolia was confirmed by synthesis. Phenylethyl caffeate and benzyl caffeate were found in B. sarothroides.