Chemical composition and antiglycoxidant activities of French organic propolis extracts

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Polyphenolic content and pharmacological potential of french BFA propolis extracts

Propolis, or bee glue, is a natural resinous hive product collected by honeybees from buds and exudates of various trees and plants. Mixed with beewax and salivary enzymes, it is employed to fill cracks and embalm dead invaders in the hive. Propolis has been used in folk medecine since ancien times due to its pharmacological potential associated with antioxidant, antifungal, antibacterial as well as antitumoral properties. A batch of various French propolis extracts, supplied by “Ballot-Flurin Apiculteurs” (BFA), a company located in the South-West of France and specialized in apitherapy products, was fractionated and analysed by HPLC/MS. Its qualitative chemical composition highlights the presence of polyphenols such as hydroxycinnamic acid derivatives and flavonoids. Total polyphenol content and antioxidant activities were evaluated on six BFA propolis extracts, using respectively Folin-Ciocalteu, DPPH and ORAC assays. Preliminary antifungal (Candida albicans) and antibacterial (Staphylococcus aureus) evaluations will also be given

Chemical composition, antioxidant and anti-AGEs activities of a French propolis

Accumulation in tissues and serum of advanced glycation end-products (AGEs) plays an important role in pathologies such as Alzheimer\u27s disease or, in the event of complications of diabetes, atherosclerosis or renal failure. Therefore there is a potential therapeutic interest in natural antioxidants with true anti-AGEs capabilities for the prevention of this kind of pathologies. The aim of this study was to evaluate the antioxidant and anti-AGEs potential of a French propolis batch (natural resinous substance collected by honeybees from differents plants and trees), then to identify the main compounds responsible for this anti-AGEs effect. For this purpose, the phytochemical composition of a 70% ethanolic extract of propolis (EEP70) was determined, using HPLC/DAD/MS and/or 1H and 13C NMR (1D and 2D) analysis. This study showed the presence of phenolic acids and their esters as well as flavonoids. Then, the evaluation of the antioxidant, using DPPH and ORAC assays, and the anti-AGEs potential, using an automated test recently developed in our laboratory, showed that EEP70 exhibited both high antioxidant (1650 ± 149 µmol TE/g) and anti-AGEs (IC50=0.03 mg/ml) activities. A bio-guided fractionation allowed us to identify the most active anti-AGEs compounds: pinobanksin-3-acetate (IC50=0.06 mM) which is the major compound of EEP70. Thus, EEP70 represents a good candidate as food additive to prevent glycoxidation. Boisard S, Le Ray A-M, Gatto J, Aumond M-C, Blanchard P, Derbré S, Flurin C, Richomme P: Chemical Composition, Antioxidant and Anti-AGEs Activities of a French Poplar Type Propolis. J Agric Food Chem 2014, 62:1344–1351

Chemical Composition and Antioxidant Activity of French BFA Propolis extracts

Introduction: Propolis is a resinous natural substance collected by honeybees from buds and exudates of various trees and plants, mixed with beewax and salivary enzymes. Bees generally use it as a sealer, to smooth out the internal walls of the hive as well as a protective barrier against intruders. Several pharmacological activities have been attributed to propolis extracts, mainly antibacterial, antiviral, antifungal, antitumoral but also antioxidant properties we will focus on here. Research methods: A mixture of 24 batches of French propolis, supplied by “Ballot-Flurin Apiculteurs” (BFA), a company located in the South-West of France, was extracted with five different solvents: water, 70% ethanol, methanol, methylene chloride and a mixture of solvents (methylene chloride/methanol/water). Their chemical composition was determined by High Performance Liquid Chromatography coupled with Diode Array Detector (HPLC/DAD) and with Mass Spectrometry (HPLC/MS) profilings followed, when necessary, by Nuclear Magnetic Resonance (NMR) 1D and 2D studies. Total polyphenol content and antioxidant activities were evaluated for these five BFA propolis extracts using respectively Folin-Ciocalteu, 2,2-diPhenyl-1-PicrylHydrazyl (DPPH) and Oxygen Radical Absorbance Capacity (ORAC) assays. Results and discussion: All extracts of BFA French propolis exhibited phenolic acids and esters as well as flavonoids, except for the aqueous one which predominantly contained phenolic acids. They also showed high antioxidant activities, about 2-5 times higher than an ethanolic rosemary extract which was recently approved as a food additive in Europe (E392). Therefore, among these extracts, the aqueous one offers the advantage of a strong antioxidant activity combined with a “green extraction”, when toxic residual solvents are a real issue in pharmaceutical, cosmetic and food additive products

Different phytochemical compositions of propolis samples collected in Ivory Coast, Africa

Propolis, or bee glue, is a natural resinous hive product collected by honeybees from buds and exudates of various trees and plants. Mixed with beewax and salivary enzymes, it is used to fill in cracks and holes in the hive as well as a chemical weapon against intruders. It is well known that the chemical composition of propolis depends on the flora at the site of collection. Therefore propolis are generally classified as "poplar-type" in temperate zones and "green Brazilian", "Clusia", "Macaranga" as well as Mediterranean-type in tropical zones [1]. The aim of this work was i) to study the phytochemical composition of EtOH extracts from six batches collected in different regions of Ivory Coast, using GC/MS and HPLC/UV/MSn profilings followed, when necessary, by 1D and 2D NMR analysis, and ii) to evaluate their antioxidant and anti-AGEs activities using respectively DPPH and BSA assays. One of the six propolis samples, originating from Katiola, exhibited an unusual chemical composition (flavonoids and phenolic acids derivatives) associated to a poplar-type propolis [2]. The EtOH extract showed a high antioxidant activity of 1066±15 µmol TE/g (control: rosemary EtOH extract at 591±21 µmol TE/g) and an excellent anti-AGEs activity with an IC50 of 20 µg/mL (control: Styphnolobium japonicum EtOH extract at 90 µg/mL). The other propolis extracts exhibited, as expected for tropical type samples, triterpenoids as major constituents accompanied with minor polyphenols such as prenylated flavanones, chlorogenic acid, or biflorin. Therefore the composition of the propolis collected in Katiola appears as quite unusual and we are now working on the analysis of its botanical origin

Poplar-type propolis components as trapping agents to prevent the formation of Advanced Glycation End-products (AGEs)

Propolis is a complex mixture used by bees to seal off hives, or use as a chemical weapon against intruders. Propolis is mainly composed of plant resins and beeswax so that its chemical composition, and consequently biological activity, varies with collection sites. Therefore propolis is generally classified as "poplar-type" in temperate zones vs "green Brazilian", "Clusia", "Macaranga" or Mediterranean-type in tropical zones [1].  The antiglycation potential of an organic poplar-type propolis sample had been already evaluated by our team. This study revealed that a DCM extract exhibited a strong anti-AGEs activity (IC50 28 µg/mL vs 90 µg/mL for the reference i.e. an EtOH extract of Styphnolobium japonicum) [2]. A bioassay-guided fractionation highlighted the major anti-AGEs components of this extract as pinobanksine derivatives and prenyl cafeate. The present workaims to show that the associated inhibition mechanism is directly related to their trapping ability of reactive dicarbonyl species such as methylglyoxal, an intermediate component in AGEs formation (Figure 1). Fig. 1.  The Maillard reaction - Schematic formation of AGEs. Rapid identification of chemical markers is an important issue in propolis studies. A fast dereplication analysis of the propolis DCM extract, using a Laser Desorption Ionization (LDI) MS technique [3], allowed us to instantly identify 25 polyphenol derivatives previously identified by classical methods [2,4]. The results clearly show that LDI-MS represents a fast and powerful method to characterize propolis extracts and identify their origin. References: [1] Salatino A, Fernandes-Silva CC, Righi AA, Salatino MLF. Propolis research and the chemistry of plant products. Nat Prod Rep 2011; 28: 925–936 [2] Boisard S, Le Ray A-M, Gatto J, Aumond M-C, Blanchard P, Derbré S, Flurin C, Richomme P. Chemical Composition, Antioxidant and Anti-AGEs Activities of a French Poplar Type Propolis. J Agric Food Chem 2014; 62: 1344–1351 [3] Le Pogam P, Schinkovitz A, Legouin B, Le Lamer A-C, Boustie J, Richomme P. Matrix-​Free UV-​Laser Desorption Ionization Mass Spectrometry as a Versatile Approach for Accelerating Dereplication Studies on Lichens. Anal Chem 2015; 87: 10421-8 [4] Boisard S, Le Ray A-M, Landreau A, Kempf M, Cassisa V, Flurin C, Richomme P. Antifungal and Antibacterial Metabolites from a French Poplar Type Propolis. Evid Based Complement Alternat Med 2015; e319240

Anti-AGEs and antiparasitic activity of an original prenylated isoflavonoid and flavanones isolated from Derris ferruginea

A new isoflavonoid, 5-hydroxy-3-(4-hydroxyphenyl)-8-isopropenyl-8,9-dihydro-4H-furo-[2,3-h]-chromen-4-one named derrisisoflavone G (1), four known prenylated flavanones (2–5), four known isoflavonoids (6–9) and two phenolic derivatives (10, 11) have been isolated from crude extracts of Derris ferruginea stems and leaves. Compounds 1–11 were identified using spectroscopic methods whereas an unambiguous structural assignment of 1 was accomplished through hemi-synthesis. Compounds 2–5 exhibited strong in vitro antiparasitic activity against Plasmodium falciparum and Leishmania major but with poor selectivity, whereas 1–5 significantly inhibited the formation of advanced glycation endproducts (AGEs)

Secondary metabolites from lichen as potent inhibitors of advanced glycation end products and vasodilative agents

Secondary metabolites from lichens are known for exhibiting various biological effects such as anti-inflammatory, antioxidant and antibacterial activities. Despite this wide range of reported biological effects, their impact on the formation of advanced glycation end products (AGEs) remains vastly unexplored. The latter are known contributors to lifestyle and age-related diseases such as Alzheimer and Parkinson. Moreover, the development of atherosclerosis and arterial stiffness is causally linked to the formation of AGEs. With this in mind, the present work evaluated the inhibitory effects of secondary lichen metabolites on the formation of pentosidine-like AGEs by using an in vitro, Maillard reaction based, fluorescence assay. Overall, thirty-seven natural and five synthetically modified compounds were tested, eighteen of which exhibiting IC50 values in the range of 0.05 to 0.70 mM, which corresponds to 2 to 32 fold of the inhibitory activity of aminoguanidine. In addition, all compounds were evaluated on their radical scavenging capacities in an DPPH assay targeting one major inhibiting mechanism of AGEs formation. Furthermore, as both AGEs\u27 formation and hypertension are major risk factors for atherosclerosis, compounds that were available in sufficient amounts were also tested for their vasodilative effects. Although some of the active compounds were previously reported cytotoxic, present results highlight the interesting potential of secondary lichen metabolites as anti-AGE and vasodilative agents