chrysin and caffeic-acid

The angiotensin-converting enzyme (ACE)-related carboxypeptidase, ACE-II, is a type I integral membrane protein of 805 amino acids that contains 1 HEXXH-E zinc binding consensus sequence. ACE-II has been implicated in the regulation of heart function and also as a functional receptor for the coronavirus that causes the severe acute respiratory syndrome (SARS). In this study, the potential of some flavonoids presents in propolis to bind to ACE-II receptors was calculated with in silico. Binding constants of ten flavonoids, caffeic acid, caffeic acid phenethyl ester, chrysin, galangin, myricetin, rutin, hesperetin, pinocembrin, luteolin and quercetin were measured using the AutoDock 4.2 molecular docking program. And also, these binding constants were compared to reference ligand of MLN-4760. The results are shown that rutin has the best inhibition potentials among the studied molecules with high binding energy - 8.04 kcal/mol, and it is followed by myricetin, quercetin, caffeic acid phenethyl ester and hesperetin. However, the reference molecule has binding energy of - 7.24 kcal/mol. In conclusion, the high potential of flavonoids in ethanolic propolis extracts to bind to ACE-II receptors indicates that this natural bee product has high potential for COVID-19 treatment, but this needs to be supported by experimental studies.

Topics: Angiotensin-Converting Enzyme 2; Animals; Bees; Caffeic Acids; COVID-19 Drug Treatment; Flavanones; Flavonoids; Hesperidin; Humans; Luteolin; Molecular Docking Simulation; Phenylethyl Alcohol; Plant Extracts; Propolis; Quercetin; Rutin

Clinical use of cyclophosphamide (CP) causes apoptosis-induced cell death in the immune system, liver, heart and kidneys. To prevent the cells against side effects of CP and its metabolites, increasing antioxidant defence mechanism of the body with supplemental antioxidants is important. Therefore, there is a requirement for effective agents which could prevent the healthy cells from the harmful effects of drug-induced toxicities. Several antioxidants have been used in protecting or alleviating CP-induced cell death. However, no such study is reported in CP-induced SH-SY5Y cell toxicity. The aim of this study was to evaluate likelihood ameliorative effects of caffeic acid, chrysin, quercetin and ferulic acid against CP-induced toxicity in SH-SY5Y neuron cells. In this study protective effects of quercetin, chrysin, caffeic acid and ferulic acid against CP-induced cell toxicity in SH-SY5Y cells was evaluated by cell proliferation assay, lipid peroxidation (LPO) analysis to decipher antioxidant capacity, tunel assay and qRT-PCR experiments to examine anti-apoptotic activities of the antioxidants. The results showed that CP-induced cell toxicity in SH-SY5Y cells and treatments with the antioxidants suppressed the cell death. Our results suggests that these anti-oxidants protected SH-SY5Y cells via a decrease in LPO levels, downregulating the expression of Cas-3, Cyt c and Bax and upregulating expression of anti-apoptotic gene Bcl-2. The use of antioxidant as nutritional supplements, and in particular of caffeic acid, chrysin, quercetin and ferulic acid, reduce apoptotic effects of CP in SH-SY5Y cells that could add insight into therapeutic approaches to CP-induced cell injuries.

Topics: Antineoplastic Agents, Alkylating; Antioxidants; Apoptosis; Caffeic Acids; Cell Line, Tumor; Cell Proliferation; Cell Survival; Coumaric Acids; Cyclophosphamide; Flavonoids; Humans; Lipid Peroxidation; Neurons; Neuroprotective Agents; Quercetin

Phytochemicals are ubiquitous in naturally occurring dietary elements that exhibits diverse pharmacological properties over various pathological disorders, including cancer. Voltage gated K

Topics: Antineoplastic Agents, Phytogenic; Caffeic Acids; Cell Line, Tumor; Flavanones; Flavonoids; Gallic Acid; Guaiacol; Humans; Ion Transport; Male; Membrane Potentials; Patch-Clamp Techniques; PC-3 Cells; Phytochemicals; Potassium; Potassium Channels, Voltage-Gated

Propolis is an important bee product which has been applied to the treatment of several diseases. The aim of this study was to understand the material basis of Chinese propolis on pain relief; different Chinese propolis fractions (40W, 40E, 70E, and 95E raw propolis extracted followed by 40%, 70%, or 95% ethanol) were prepared, and their antinociceptive effects were evaluated. By analyzing using UPLC-Q-TOF-MS, we showed that 40W was rich in phenolic acids, like caffeic acid, while 40E, 70E, and 95E have relatively high levels in flavonoids, like galangin, pinocembrin, and chrysin. Notably, chrysin amounts in 70E and 95E are much higher than those in 40E fraction. Antinociceptive effects by these propolis fractions were evaluated in mice using acetic acid-induced writhing test, hot plate test, and tail immersion test, respectively. We noticed that only 40E fraction showed a significant reduction on acetic acid-induced writhing test. Importantly, in the hot plate test, all groups showed their effectiveness, except for the 70E group. We also noticed that 40W, 40E, and 95E administration caused an increase in the tail withdrawal latency of the mice. These data suggested that the different antinociceptive effects of different fractions from Chinese propolis extracts are directly link to their flavonoid composition.

Topics: Acetic Acid; Analgesics; Animals; Caffeic Acids; Chemical Fractionation; Chromatography, High Pressure Liquid; Flavonoids; Hydroxybenzoates; Male; Medicine, Chinese Traditional; Mice; Models, Animal; Propolis; Visceral Pain

Aqueous and ethanol extracts of propolis were analysed phytochemically and examined for their antiviral activity in vitro. Different polyphenols, flavonoids and phenylcarboxylic acids were identified as major constituents. The antiviral effect of propolis extracts and selected constituents, e.g. caffeic acid (1), p-coumaric acid (2), benzoic acid (3), galangin (4), pinocembrin (5) and chrysin (6) against herpes simplex virus type 1 (HSV-1) was analysed in cell culture. The 50% inhibitory concentration (IC(50)) of aqueous and ethanol propolis extracts for HSV-1 plaque formation was determined at 0.0004% and 0.000035%, respectively. Both propolis extracts exhibited high levels of antiviral activity against HSV-1 in viral suspension tests, plaque formation was significantly reduced by >98%. In order to determine the mode of antiviral action of propolis, the extracts were added at different times during the viral infection cycle. Both propolis extracts exhibited high anti-HSV-1 activity when the viruses were pretreated with these drugs prior to infection. Among the analysed compounds, only galangin and chrysin displayed some antiviral activity. However, the extracts containing many different components exhibited significantly higher antiherpetic effects as well as higher selectivity indices than single isolated constituents. Propolis extracts might be suitable for topical application against herpes infection.

Topics: Animals; Antiviral Agents; Benzoic Acid; Caffeic Acids; Cell Line; Coumaric Acids; Dose-Response Relationship, Drug; Flavanones; Flavonoids; Herpesvirus 1, Human; Inhibitory Concentration 50; Molecular Structure; Propionates; Propolis

This in vitro study aimed to evaluate the possible radioprotective effects of the natural substances WSDP, caffeic acid, chrysin and naringin on gamma-irradiated human white blood cells. The effectiveness of tested compounds was evaluated using the alkaline comet assay, the analysis of structural chromosome aberration and the cytokinesis-block micronucleus assay. The results obtained by the alkaline comet study indicate favourable toxicity profiles of propolis and its polyphenolic components, and confirmed the radioprotective abilities comparable to the chemical radioprotector AET. WSDP and its polyphenolic components were able to reduce the number of necrotic cells. None of tested compounds induced significant genotoxicity, but all of them offered a quite measurable protection against DNA damage. WSDP was found to be the most effective in diminishing the levels of primary and more complex cytogenetic DNA damage in white blood cells. Considering its complex composition, to undoubtedly explain the underlying mechanisms of cyto/radioprotective effects, further studies are needed.

Topics: Caffeic Acids; Chromosome Aberrations; Comet Assay; DNA Damage; Flavanones; Flavonoids; Humans; Leukocytes; Male; Micronucleus Tests; Middle Aged; Phenols; Polyphenols; Propolis; Radiation-Protective Agents

Effect of two preparation (Croatian and Brazilian) of water-soluble derivative of propolis (WSDP), caffeic acid, quercetin, chrysin, naringenin (components present in WSDP) on the development of Ehrlich ascites tumour (EAT) was evaluated. Test components (50 mg/kg) were given perorally or intraperitoneally 2 h prior the intraperitonel injection of EAT (2 x 10(6)) cells. It was observed that all test compounds effectively inhibited tumour growth and the proliferation of EAT. The volume of ascitic fluid induced by EAT cells and total number of cells present in the peritoneal cavity was markedly reduced in EAT-bearing mice treated with test components. In treated mice the number of polymorphonuclear (PMN) cells in the peritoneal cavity was increased while the number of macrophages was decreased. The macrophage spreading activity revealed that WSDP and all test compounds affected the functional state of macrophages increasing their tumorcidal activity; the effect of WSDP was most pronounced indicating synergistic effect of components present in WSDP. Antitumor activity of WSDP may be the result of different specific mechanism(s) of flavonoids present as compared to individual flavonoid given alone. It is likely that the part of antitumor efficacy of test components against EAT cells was the results of increased activity of macrophages.

Topics: Administration, Oral; Animals; Antineoplastic Agents; Ascitic Fluid; Caffeic Acids; Carcinoma, Ehrlich Tumor; Drug Synergism; Flavanones; Flavonoids; Injections, Intraperitoneal; Macrophages; Mice; Peritoneal Cavity; Phenols; Polyphenols; Propolis; Quercetin

Thin-layer chromatography of ethanolic extract of propolis (EEP) from the continental and Adriatic regions of Croatia showed that 72.2% of propolis samples contain galangin, 88.8% of samples contain kaempferol, naringenin and apigenin and 66.6% of samples contain caffeic acid. Caffeic acid, pinocembrin, galangin, chrysin and naringenin were analyzed by HPLC. In all samples, pinocembrin was the dominant flavonoid. In samples from the Adriatic region, concentration of pinocembrin ranged from 0.03 to 6.14% (x = 2.87%) and in the continental region samples from 0 to 4.74% (x = 2.84%). Chrysin was found in all propolis samples in a concentration ranging from 0.22 to 5.32% (x = 1.86%) in the continental region samples and from 0.03 to 3.64% (x = 1.96%) in samples from the Adriatic region. Chrysin was followed by naringenin, ranging from 0 to 1.14% (x = 0.42%) in samples from the Adriatic region and from 0.22 to 2.41% (x = 0.60%) in the continental region samples. Concentration of caffeic acid ranged from 0 to 10.11% (x = 2.69%) in the Adriatic region samples and from 0.27 to 2.67% (x = 1.37%) in samples from the continental region of Croatia. Results of HPLC analyses suggest that propolis samples collected from various parts of Croatia do not differ markedly in contents of chrysin, pinocembrin, naringenin and galangin but differ in the concentration of caffeic acid. All EEPs significantly inhibited the growth of Bacillus subtilis in comparison with the control (80% ethanol) (p < 0.05), showing inhibition zones of 16 +/- 2 mm for samples from the continental region, and of 18 +/- 3 mm for samples from the Adriatic region. There was no significant difference in antimicrobial activity of EEPs from the continental and Adriatic regions of Croatia, suggesting that bactericidal activity depends on synergism of all phenolic compounds.

Topics: Animals; Anti-Infective Agents; Apigenin; Bacillus subtilis; Bees; Caffeic Acids; Croatia; Flavanones; Flavonoids; Kaempferols; Microbial Sensitivity Tests; Propolis

A number of natural phenolic compounds display antioxidant and cell protective effects in cell culture models, yet in some studies show prooxidant and cytotoxic effects. Pancreatic beta-cells have been reported to exhibit particular sensitivity to oxidative stress, a factor that may contribute to the impaired beta-cell function characteristic of diabetes. The aim of this study was to examine the potential of natural phenolics to protect cultured pancreatic beta-cells (betaTC1 and HIT) from H(2)O(2) oxidative stress. Exposure of cells to H(2)O(2) led to significant proliferation inhibition. Contrary to what one should expect, simultaneous exposure to H(2)O(2) and the phenolics, quercetin (10-100 microM), catechin (50-500 microM), or ascorbic acid (100-1000 microM), led to amplification of proliferation inhibition. At higher concentrations, these compounds inhibited proliferation, even in the absence of added H(2)O(2). This prooxidant effect is attributable to the generation of H(2)O(2) through interaction of the added phenolic compounds with as yet undefined componenets of the culture media. On the other hand, inclusion of metmyoglobin (30 microM) in the culture medium significantly reduced the prooxidant impact of the phenolics. Under these conditions, quercetin and catechin significantly protected the cells against oxidative stress when these components were present during the stress period. Furthermore, significant cell protection was observed upon preincubation of cells with chrysin, quercetin, catechin, or caffeic acid (50 microM, each) prior to application of oxidative stress. It is concluded that provided artifactual prooxidant effects are avoided, preincubation of beta-cells with relatively hydrophobic natural phenolics can confer protection against oxidative stress.

Topics: Animals; Antioxidants; Ascorbic Acid; Caffeic Acids; Catechin; Cell Division; Cell Line; Flavonoids; Hydrogen Peroxide; Islets of Langerhans; Lipid Peroxidation; Metmyoglobin; Mice; Oxidants; Oxidative Stress; Phenols; Quercetin