Hamamelis virginiana L. extract presents antimicrobial and antibiofilm effects, absence of cytotoxicity, anti-inflammatory action, and potential to fight infections through the nitric oxide production by macrophages.

The potential of H. virginiana L. was evaluated against Candida spp. (C. albicans, C. dubliniensis, C. glabrata, C. guilliermondii, C. krusei, and C. tropicalis) and bacteria (Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus mutans). Effect on murine macrophages (RAW 264.7) was also evaluated with respect to cytotoxicity and production of cytokines (IL-1ß and TNF-α) and nitric oxide (NO). The most effective concentrations of the extract were determined by microdilution broth. These concentrations were analyzed on biofilms, after 5 min or 24 h exposure. Cytotoxicity was performed by MTT assay and quantification of cytokines and NO by ELISA and Griess reagent, respectively. The extract acted against the planktonic forms and provided significant reductions of all the microbial biofilms; besides, showed no cytotoxic effect, except at 100 mg/mL, after 24 h exposure. There was cytokine production; however, a modulatory effect was observed in groups exposed to lipopolysaccharide (LPS) from E. coli. NO production was similar or higher than the control group. Thus, H. virginiana L. extract showed antimicrobial and antibiofilm effects; absence of cytotoxicity for RAW 264.7; anti-inflammatory action; and potential to fight infections through the NO production.

Metabolomic fingerprint of Hamamelis virginiana L. gallotannins by suspect screening analysis with UHPLC-qToF and their semiquantitative evaluation.

The evolution of the regulatory framework for medical devices in the EU (Reg 2017/745) has opened the study of complex systems emerging properties. This makes necessary to identify new analytical approaches able of characterizing complex natural substrates as completely as possible. Therefore, omics approaches and advanced analytical methods for the determination of metabolite classes appear to be at the forefront to meet this need. In this perspective, a new approach based on the suspect screening was developed to detect gallotannins. Gallotannins are a class of phenols with a polymeric nature; thus, there are no pure analytical standards available for all possible structures and their quali-quantitative determination in complex natural substrates can be a challenge. A new UHPLC-qToF method was developed and used to create an "in-house tannin database" with a dual purpose: (1) as a classic list of suspects and (2) to identify core fragments common to gallotannins to have another list of putative suspects based on the common fragment. The method was validated. The application of the method to a "system of molecules" extracted from the leaves of Hamamelis virginiana L. (Witch-hazel) allowed to the characterization of a total of 29 phenols by a suspect screening approach. Therefore, 15 gallotannins were putatively annotated while another 3 were confidently identified. All the gallotannins were semiquantified according to external regression curves of gallic acid and hamamelitannin based on core fragments at m/z 125.0244 and m/z 169.0142, the building blocks of the polymers. This new method provides a practical fit-to-purpose approach for the quali-quantitative screening evaluation of gallotannins, useful for creating multivariate control charts applicable in process development of complex natural systems or in quality control. The approach is innovative, and after specific checks, it can in principle be suitable for metabolomic fingerprint analysis of gallotannins among witch-hazel extract (WHE) samples.

Unveiling the Ability of Witch Hazel (Hamamelis virginiana L.) Bark Extract to Impair Keratinocyte Inflammatory Cascade Typical of Atopic Eczema.

Hamamelis virginiana L. bark extract is a traditional remedy for skin affections, including atopic dermatitis/eczema (AD). Hamamelis preparations contain tannins, including hamamelitannin (HT), although their pharmacological role in AD is still unknown. This study aimed to study the rational for its topical use by considering the impact of crucial biomarkers on AD pathogenesis. A standardized extract (HVE) (0.5−125 µg/mL) was compared to hamamelitannin (HT), its main compound (0.5−5 µg/mL), in a model of human keratinocytes (HaCaTs), challenged with an AD-like cytokine milieu (TNF-α, IFN-γ, and IL-4). HVE inhibited the release of mediators involved in skin autoimmunity (IL-6 and IL-17C) and allergy (TSLP, IL-6, CCL26, and MMP-9) with a concentration-dependent fashion (IC50s < 25 µg/mL). The biological mechanism was ascribed, at least in part, to the impairment of the NF-κB-driven transcription. Moreover, HVE counteracted the proliferative effects of IL-4 and recovered K10, a marker of skin differentiation. Notably, HT showed activity on well-known targets of IL-4 pathway (CCL26, K10, cell proliferation). To the best of our knowledge, this work represents the first demonstration of the potential role of Hamamelis virginiana in the control of AD symptoms, such as itch and skin barrier impairment, supporting the relevance of the whole phytocomplex.

Avaliação in vitro da atividade antimicrobiana dos extratos de Calendula officinalis, Capsicum annuum L e Hamamelis virginiana L. sobre cepas clínicas multirresistentes de Klebsiella pneumoniae e Pseudomonas aeruginosa / In vitro Evaluation of antimicrobial activity of extracts from Calendula officinalis, Capsicum annuum L and Hamamelis virginiana L. on multiresistant clinical straines of Klebsiella pneumoniae and Pseudomonas aeruginosa

O conhecimento dos efeitos dos extratos naturais de plantas vem cada vez mais se mostrando um campo promissor. Extratos de Calendula officinalis, Capsicum annuum e Hamamelis virginiana apresentam propriedades analgésicas, anti-inflamatórias, antioxidantes e potencial antimicrobiano que deve ser aprofundado. Assim, o objetivo foi avaliar ação antimicrobiana dos extratos glicólicos em culturas planctônicas e biofilmes de cepas padrão e clínicas de Klebsiella pneumoniae e Pseudomonas aeruginosa. Foi realizado o teste de microdiluição em caldo segundo Clinical and Laboratory Standards Institute, para determinação da Concentração Inibitória Mínima (CIM) e Concentração Microbicida Mínima (CMM) dos extratos. Foram realizados biofilmes monotípicos, nos tempos de contato de 5 min e 24 h, utilizando o teste de MTT. A CIM e CMM variaram de 1,56 a 50 mg/mL para todas as cepas avaliadas. C. annuum (50 mg/mL) apresentou redução de 0,25% entre 8,60% para cepa ATCC de P. aeruginosa (5 min) e em 24 h redução de 99,89% entre 99,99%, destacando-se os extratos de C. annuum (100 mg/mL) e os de C. officinalis. C. annuum (200 mg/mL) apresentou redução de 18% de K. pneumoniae (ATCC 4352). Em 24 h houve redução de 8,86%-75,74%, para o extrato de C. annuum (100 mg/mL). Os extratos apresentaram resultados mais satisfatórios quando expostos aos tratamentos de 24 horas. As cepas clínicas K1, K2 e K3 responderam ao tratamento de C. annuum (50 e 100 mg/mL) (p>0,05%). Para cepa clínica K4, os extratos de C. annuum (50 e 100 mg/mL) e C. officinalis (12,5 mg/mL) promoveram redução de viabilidade semelhante a clorexidina 2% (p>0,05%). O extrato de C. annuum (50 e 100 mg/mL), promoveu a redução de viabilidade de P1 e P2, enquanto o extrato de C. officinalis (25 e 50 mg/mL), reduziu P1 (p>0,05%). Para as cepas P3 e P4 o extrato de 50 e 100 mg/mL de C. annuum, apresentaram resultados semelhantes a clorexidina. Conclui-se que todos os extratos apresentaram ação antimicrobiana em cultura planctônica, no entanto, o extrato de C. annuum foi o que apresentou importante ação antibiofilme (24 h) sobre cepas clínicas multirresistentes de K. pneumoniae e P. aeruginosa, podendo ser considerado um potencial agente antimicrobiano.

Empirical knowledge of natural plant extracts is increasingly proving to be a promising field. Extracts of Calendula officinalis, Capsicum annuum and Hamamelis virginiana have analgesic, anti-inflammatory, antioxidant and antimicrobial potential that should be further developed. This research objective was to evaluate the antimicrobial action of glycolic extracts in planktonic cultures and biofilms of standard and clinical strains of Klebsiella pneumoniae and Pseudomonas aeruginosa. The broth microdilution test was performed according to the Clinical and Laboratory Standards Institute, to determine the Minimum Inhibitory Concentration (MIC) and Minimum Microbicide Concentration (MMC) of the extracts. Tests were performed on monotypic biofilms, at contact times of 5 min and 24 h, using the MTT test. The MIC and CMM of the extracts ranged from 1.56 to 50 mg/mL for all strains evaluated. C. annuum (50 mg/mL) showed a reduction of 0.25% between 8.60% for the ATCC strain of P. aeruginosa (5 min) and in 24 h a reduction of 99.89% between 99.99%, highlighting extracts from C. annuum (100 mg/mL) and from C. officinalis. C. annuum (200 mg/mL) showed an 18% reduction in K. pneumoniae (ATCC 4352). In 24 h there was a reduction of 8.86% between 75.74% for the extract of C. annuum (100 mg/mL). The extracts showed more satisfactory results when exposed to 24-hour treatments. Clinical strains K1, K2 and K3 responded to the treatment of C. annuum (50 and 100 mg/mL) (p>0.05%). For clinical strain K4, extracts of C. annuum (50 and 100 mg/mL) and C. officinalis (12.5 mg/mL) promoted a reduction in viability similar to chlorhexidine 2% (p>0.05%). The extract of C. annuum (50 and 100 mg/mL), reduced the viability of P1 and P2, while the extract of C. officinalis (25 and 50 mg/mL), reduced P1 (p>0.05% ). For strains P3 and P4, the extract of 50 and 100 mg/mL of C. annuum showed similar results to chlorhexidine. It is concluded that all extracts showed antimicrobial action in planktonic cultures, however, the extract of C. annuum was the one that showed an important antibiofilm action (24 h) on multiresistant clinical strains of K. pneumoniae and P. aeruginosa and can be considered a potential antimicrobial agent

Extratos de romã e hamamélis: existe ação antimicrobiana sobre cepas clínicas de Acinetobacter baumannii e Klebsiella pneumoniae multirresistentes? / Pomegranate and witch hazel extracts: is there antimicrobial action on clinical strains of multiresistant Acinetobacter baumannii and Klebsiella pneumoniae?

Acinetobacter baumannii e Klebsiella pneumoniae são patógenos prioritários globais resistentes a antibióticos, portanto, é relevante encontrar métodos alternativos para controlá-los, e os fitoterápicos têm sido investigados para essa finalidade. Em vista disso, o objetivo desse estudo foi avaliar a atividade antimicrobiana e antibiofilme do extrato glicólico de Hamamelis virginiana (hamamélis) e do extrato hidroalcóolico de Punica granatum (romã) isolados e em combinação sobre cepas ATCC e clínicas de A. baumannii e K. pneumoniae. Primeiramente, foi determinada a Concentração Inibitória Mínima (CIM) e a Concentração Microbicida Mínima (CMM) pelo teste de microdiluição em caldo, segundo Clinical and Laboratory Standards Institute (CLSI), após, o potencial antimicrobiano da combinação entre esses extratos foi analisado sobre esses micro-organismos por meio da técnica "checkerboard". Posteriormente, a redução da atividade metabólica dos biofilmes foi avaliada pelo teste de MTT (contato de 5 min e 24h), para tanto a CMM e as duas concentrações acima dela foram utilizadas. A concentração correspondente a 2X a CMM dos extratos combinados foi utilizada no teste de MTT para o tratamento dos biofilmes no tempo de 5 min e 24h. Os extratos isolados e combinados apresentaram ação microbicida contra A. baumannii e K. pneumoniae na forma planctônica. O extrato de romã apresentou CMM de 1,71 a 3,43 mg/mL para A. baumannii e de 3,43 a 13,75 mg/mL para K. pneumoniae, enquanto que Hamamélis exibiu CMM de 12,5 a 25 mg/mL para A. baumannii e de 25 a 50 mg/mL para K. pneumoniae. O uso combinado dos extratos resultou em treze concentrações aditivas para A. baumannii e quinze para K. pneumoniae. A redução de viabilidade em biofilmes de A. baumannii chegou a 64,94% para o extrato de romã, e 83,45% para o extrato de Hamamélis. K. pneumoniae apresentou redução máxima de 75,66% com extrato de Romã e de 76,56% com o extrato de Hamamelis. A redução do biofilme variou conforme a concentração e cepa quando tratado com a combinação dos extratos. Com isso, pode-se concluir que os extratos apresentam importante ação antibacteriana e antibiofilme sobre os patógenos avaliados, podendo ser considerados potenciais agentes terapêuticos para o combate destes patógenos.

Pomegranate and witch hazel extracts: is there antimicrobial action on clinical strains of multiresistant Acinetobacter baumannii and Klebsiella pneumoniae? [dissertation]. São José dos Campos (SP): São Paulo State University (Unesp), Institute of Science and Technology; 2021. ABSTRACT Acinetobacter baumannii and Klebsiella pneumoniae are global priority antibiotic resistant pathogens, therefore, it is relevant to find alternative methods to control them, and herbal medicines have been investigated for this purpose. In view of this, the aim of this study was to evaluate the antimicrobial and antibiofilm activity of the glycolic extract of Hamamelis virginiana (witch hazel) and the hydroalcoholic extract of Punica granatum (pomegranate) isolated and in combination on ATCC and clinical strains of A. baumannii and K. pneumoniae. First, the Minimum Inhibitory Concentration (MIC) and the Minimum Microbicide Concentration (MMC) were determined by the broth microdilution test, according to the Clinical and Laboratory Standards Institute (CLSI), after which the antimicrobial potential of the combination of these extracts was analyzed on these microorganisms through the "checkerboard" technique. Subsequently, the reduction of the metabolic activity of biofilms was evaluated by the MTT test (5 min and 24h contact), for both the CMM and the two concentrations above it were used. The concentration corresponding to 2X the CMM of the combined extracts was used in the MTT test for the treatment of biofilms in a time of 5 min and 24h. The isolated and combined extracts showed microbicidal action against A. baumannii and K. pneumoniae in the planktonic form. The pomegranate extract showed MMC from 1.71 to 3.43 mg/mL for A. baumannii and from 3.43 to 13.75 mg/mL for K. pneumoniae, while Witch Hazel exhibited MMC from 12.5 to 25 mg µg/ml for A. baumannii and from 25 to 50 mg/ml for K. pneumoniae. The combined use of the extracts resulted in thirteen additive concentrations for A. baumannii and fifteen for K. pneumoniae. The viability reduction in A. baumannii biofilms reached 64.94% for the pomegranate extract, and 83.45% for the Witch Hazel extract. K. pneumoniae showed a maximum reduction of 75.66% with Pomegranate extract and 76.56% with Hamamelis extract. Biofilm reduction varied according to concentration and strain when treated with the combination of extracts. Thus, it can be concluded that the extracts have an important antibacterial and antibiofilm action on the evaluated pathogens, and can be considered potential therapeutic agents to combat these pathogens.

Identification of Seasonal Variations of Antibodies against PR-10-Specific Epitopes Can Be Improved Using Peptide-Phage Display.

BACKGROUND: In pollinosis patients, allergen-specific antibody titers show seasonal variations. Little is known about these variations at the epitope level. OBJECTIVES: We aimed at investigating seasonal variations on the level of allergen epitope recognition in patients with Bet v 1-related food allergy using a peptide phage display approach. METHODS: Serum samples collected over 1 year from 4 patients of the placebo arm of the birch-associated soya allergy immunotherapy trial were included. To identify epitopes from Bet v 1-related food allergens, patient sera were used in peptide phage display experiments. In silico analysis of enriched allergen-related motifs was performed. RESULTS: We identified epitope motifs related to Bet v 1 and its homologs in soya and hazelnut (Gly m 4 and Cor a 1, respectively) that were enriched in accordance with birch and hazel pollen exposure. Within several weeks after the birch pollen season peak, the pattern of identified epitope motifs differed considerably among patients. Data for amino acid preferences in homologous Bet v 1 and Cor a 1 epitope motifs identified for one of the investigated patients suggest changes in concentration or specificity of serum antibodies for the Cor a 1 epitope motif. CONCLUSIONS: Peptide phage display data suggest an impact of birch and hazel pollen exposure on the recognition pattern of Bet v 1-like allergen epitopes. Epitope-oriented analyses could provide deeper, personalized details regarding the allergen epitope recognition influenced by pollen exposure beyond the capability of current methods.

Efficacy and tolerability of injectable collagen-containing products in comparison to trimecaine in patients with acute lumbar spine pain (Study FUTURE-MD-Back Pain).

Low back pain (LBP) represents an important subgroup of vertebrogenic pain with estimated prevalence around 80 %. Locally acting injectable collagen for topical application has recently extended the limited range of treatment options. The aim of the study was to evaluate the efficacy and safety of injectable collagen in patients with LBP. Patients suffering from LBP (< three months) were enrolled. They were administered either collagen 4 ml or trimecaine 1 % 4 ml in the form of subcutaneous paravertebral injections into eight pre-specified points (0.5 ml per each point) in the following schedule: two administrations in the first and second week, one in the third week. The pain intensity, Thomayer distance, Oswestry disability index, Lasseque test, quality of life, consumption of rescue medication and safety were evaluated. Exertional and rest pain, evaluated by a visual analogue scale, gradually decreased in both groups. Both treatments showed a statistically significant improvement in mobility and quality of life. The consumption of paracetamol as a rescue medication was significantly lower in patients treated with collagen than in the group treated with trimecaine (p=0.048). The analgesic efficacy of locally acting injectable collagen, as well as an analgesic sparing effect when compared to local anesthetics were demonstrated.

Electrospun Membranes Based on Schizophyllan-PVOH and Hamamelis Virginiana Extract: Antimicrobial Activity Against Microorganisms of Medical Importance.

Electrospinning is a micrometric or nanometric scale fiber manufacturing technique with structural factors such as greater contact surface and pore size that allows the incorporation of biological agents in its structure, increasing their potential for medical applications. Due to the conditions required for the electrospinning process, such as high voltage, in the present work, the evaluation of the antimicrobial activity of schizophyllan-based membranes elaborated by electrospinning at 20 kV incorporated with Hamamelis virginiana was carried out against Staphylococcus aureus, Candida albicans and Pseudomonas aeruginosa. The schizophyllan production was 1.97 gL-1 from strain Schizophyllum commune ScIBL1. The conditions for the process were standardized for voltage, feed flow, and the distance from the injector to the collector. Membranes with smooth-edged fibers, diameter of 819 nm without the presence of beads were obtained. However, it was found that the membranes lost antimicrobial activity against all the microorganisms evaluated, whereas, bioassays showed that null toxicity was presented.

The potential of commercially available phytotherapeutic compounds as new photosensitizers for dental antimicrobial PDT: A photochemical and photobiological in vitro study.

The present study evaluated the effectiveness of extracts of commercially available Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum as photosensitizers in Antimicrobial Photodynamic Therapy (aPDT). Each photosensitizer (PS) was analyzed in a spectrophotometer between 350 and 750 nm to determine the ideal light source. Once the absorption bands were determined, three light sources were selected. To determine the concentration of use, the compounds were tested at different concentrations on bovine dentin samples to evaluate the risk of staining. Once the concentration was determined, the PSs were evaluated for dark toxicity and phototoxicity on fibroblast and bacteria culture. Each compound was then irradiated with each light source and evaluated for the production of reactive oxygen species (ROS). The bacterial reduction was tested on E. faecalis culture in planktonic form and on biofilm using an energy of 10 J and an Energy Density of 26 J/cm2. The tested compounds exhibited light absorption in three bands of the visible spectrum: violet (405 nm), blue (460 nm) and red (660 nm). At a 1:6 concentration, none of the compounds caused tooth staining as they did not exhibit significant toxicity in the cells or bacterial suspension. Additionally, significant ROS production was observed when the compounds were irradiated at each wavelength. When aPDT was performed on the plactonic and biofilm bacteria, significant microbial reduction was observed in both cases, reaching a reduction of up to 5Logs. In conclusion, extracts of Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum exhibited potential for use as photosensitizing agents in aPDT.

Understanding Solar Skin Elastosis-Cause and Treatment.

Photoageing, also called actinic ageing, is the main cause of prematurely aged skin. Our expertise in elastic fibers has led us to discover a process triggered in response to ultraviolet (UV) light and which upsets the balance of elastin fibers: there is too much elastin and insufficient lysyl oxidase (LOXL1) enzyme to form functional elastic fibers. This imbalance then leads to an accumulation of nonfunctional elastin, which forms aggregates. In addition to this imbalance, UV rays also induce elafin synthesis by fibroblasts. Known to be a marker of elastotic aggregates, elafin crystallizes the elastin fibers and stimulates the formation of aggregates that cannot be naturally eliminated by the skin. We developed a Hamamelis virginiana leaf extract that was able to restore both the balance between elastin and LOXL1 and to decrease the elafin synthesis to fight and correct the damage. This specific Hamamelis virginiana extract increased LOXL1 expression by twofold and decreased elafin synthesis. As a consequence, elastic fibers became functional and aggregates of unfunctional fibers decreased. The specific Hamamelis extract activity was confirmed in vivo with decreasing wrinkles and improving skin firmness.

Botanicals With Dermatologic Properties Derived From First Nations Healing: Part 2-Plants and Algae.

INTRODUCTION: Plants and algae have played a central role in the treatment of skin conditions in both traditional First Nations healing and in modern dermatology. The objective of this study was to examine the evidence supporting the dermatological use of seaweed, witch hazel, bearberry, and mayapple. METHODS: Four plants and algae used in traditional First Nations treatments of skin disease were selected based on expert recommendations. Several databases were searched to identify relevant citations without language restrictions. RESULTS: Seaweed has potential clinical use in the treatment of acne and wrinkles and may be incorporated into biofunctional textiles. Witch hazel is an effective and well-tolerated treatment of inflammation and diaper dermatitis. Bearberry leaves contain arbutin, a skin-lightening agent that is an alternative for the treatment of hyperpigmentation. Mayapple contains podophyllotoxin, a treatment for condyloma accuminata, molluscum contagiosum, and recalcitrant palmoplantar warts. DISCUSSION: Common plants and algae are replete with bioactive agents that may have beneficial effects on the skin. Further research will open the door to new and innovative products in the future. Limitations of this study include that the scope of our study is limited to 4 plants and algae, a small sample of the breadth of plants used by First Nations for dermatological treatments.

Contact dermatitis as an adverse reaction to some topically used European herbal medicinal products - part 2: Echinacea purpurea-Lavandula angustifolia.

This review focuses on contact dermatitis as an adverse effect of a selection of topically used herbal medicinal products for which the European Medicines Agency has completed an evaluation up to the end of November 2013 and for which a Community herbal monograph has been produced. Part 2: Echinacea purpurea Moench-Lavandula angustifolia Mill.

Tannins from Hamamelis virginiana bark extract: characterization and improvement of the antiviral efficacy against influenza A virus and human papillomavirus.

Antiviral activity has been demonstrated for different tannin-rich plant extracts. Since tannins of different classes and molecular weights are often found together in plant extracts and may differ in their antiviral activity, we have compared the effect against influenza A virus (IAV) of Hamamelis virginiana L. bark extract, fractions enriched in tannins of different molecular weights and individual tannins of defined structures, including pseudotannins. We demonstrate antiviral activity of the bark extract against different IAV strains, including the recently emerged H7N9, and show for the first time that a tannin-rich extract inhibits human papillomavirus (HPV) type 16 infection. As the best performing antiviral candidate, we identified a highly potent fraction against both IAV and HPV, enriched in high molecular weight condensed tannins by ultrafiltration, a simple, reproducible and easily upscalable method. This ultrafiltration concentrate and the bark extract inhibited early and, to a minor extent, later steps in the IAV life cycle and tannin-dependently inhibited HPV attachment. We observed interesting mechanistic differences between tannin structures: High molecular weight tannin containing extracts and tannic acid (1702 g/mol) inhibited both IAV receptor binding and neuraminidase activity. In contrast, low molecular weight compounds (<500 g/mol) such as gallic acid, epigallocatechin gallate or hamamelitannin inhibited neuraminidase but not hemagglutination. Average molecular weight of the compounds seemed to positively correlate with receptor binding (but not neuraminidase) inhibition. In general, neuraminidase inhibition seemed to contribute little to the antiviral activity. Importantly, antiviral use of the ultrafiltration fraction enriched in high molecular weight condensed tannins and, to a lesser extent, the unfractionated bark extract was preferable over individual isolated compounds. These results are of interest for developing and improving plant-based antivirals.

Conversion of phenolic constituents in aqueous Hamamelis virginiana leaf extracts during fermentation.

INTRODUCTION: Hamamelis virginiana, known for its high level of tannins and other phenolics is widely used for treatment of dermatological disorders. Although reports on hydroalcoholic and aqueous extracts from Hamamelis leaf and bark exist, knowledge on fermented leaf preparations and the underlying conversion processes are still scant. OBJECTIVE: Aqueous Hamamelis leaf extracts were monitored during fermentation and maturation in order to obtain an insight into the bioconversion of tannins and other phenolics. METHODOLOGY: Aliquots taken during the production period were investigated by HPLC-DAD-MS/MS as well as GC-MS after derivatisation into the corresponding trimethylsilyl compounds. RESULTS: In Hamamelis leaf extracts, the main constituents exhibited changes during the observational period of 6 months. By successive depside bond cleavage, the gallotannins were completely transformed into gallic acid after 1 month. Although not completely, kaempferol and quercetin glycosides were also converted during 6 months to yield their corresponding aglycones. Following C-ring fission, phloroglucinol was formed from the A-ring of both flavonols. The B-ring afforded 3-hydroxybenzoic acid from quercetin and 3,4-dihydroxybenzoic acid as well as 2-(4-hydroxyphenyl)-ethanol from kaempferol. Interestingly, hydroxycinnamic acids remained almost stable in the same time range. CONCLUSION: The present study broadens the knowledge on conversion processes in aqueous fermented extracts containing tannins, flavonol glycosides and hydroxycinnamic acids. In particular, the analogy between the microbial metabolism of phenolics from fermented Hamamelis extracts, fermented sourdough by heterofermentative lactic acid bacteria or conversion of phenolics by the human microbial flora is indicated.

Cross-linked collagen sponges loaded with plant polyphenols with inhibitory activity towards chronic wound enzymes.

Collagen sponges loaded with polyphenols from Hamamelis virginiana were investigated as active materials for chronic wound dressings, evaluating in vitro the inhibition of two major enzymes that impair the wound healing process - myeloperoxidase (MPO) and collagenase. Prior to polyphenols loading, collagen was cross-linked with genipin to improve its biostability. The effect of genipin cross-linking and polyphenol concentration in the development of mechanically and enzymatically stable sponges was studied. The tensile strength of the cross-linked collagen increased with the increase of the cross-linking degree, coupled to decrease in the elongation and the swelling capacity of the sponges. The stability of the sponges to collagenase digestion reached maximum when 1 mM genipin was used. However, the biostability decreased more than 10-fold after loading the sponges with polyphenols (0.5 mg/mL), nevertheless, this effect was partially overcome using higher concentration of polyphenols (1 and 2 mg/mL) to inhibit collagenase. Moreover, the polyphenols released from the sponges were sufficient for complete inhibition of MPO activity. No considerable cytotoxicity of the genipin cross-linked collagen loaded with polyphenols was observed evaluating the NIH 3T3 fibroblasts viability.

Investigation on the phenolic constituents in Hamamelis virginiana leaves by HPLC-DAD and LC-MS/MS.

Aqueous and acetone/water extracts from Hamamelis virginiana leaves were investigated to obtain a thorough insight into their phenolic composition. To secure compound integrity, a gentle extraction method including the exclusion of light was used. Liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses yielded a fingerprint including 27 phenolic constituents. Quantification of the key compounds on an equivalent basis by high-performance liquid chromatography diode-array detection (HPLC-DAD) showed that gallotannins consisting of six to 11 galloyl units constitute the main fraction, whereas procyanidins and catechin represented only a minor part. Closer inspection revealed that both extracts possess virtually the same galloyl hexose distribution, and the octagalloyl hexose represents the major tannin constituent. Additionally, eight flavonol glycosides and their corresponding aglycones quercetin and kaempferol, as well as three chlorogenic acid isomers and other hydroxycinnamic acids, were identified. Moreover, stability studies on the aqueous extract (5 °C, dark; room temperature, dark; room temperature, light) revealed that the phenolic profile underwent changes when exposed to light. Especially the gallotannins proved to be considerably unstable which may result in phytochemically altered Hamamelis leaf extracts upon transport and storage.

Hamamelis, el mejor aliado de la circulación sanguínea / Hamamelis, an ally of the bloodstream

Mucha gente sufre de dolores en las extremidades porque tiene una deficiente circulación sanguínea. Contrario a lo que pudiera pensarse, esta situación no es exclusiva de la vejez ya que puede presentarse, incluso, a partir de la segunda década de la vida.

Hamamelis, el mejor aliado de la circulación sanguínea / Hamamelis, an ally of the bloodstream

Mucha gente sufre de dolores en las extremidades porque tiene una deficiente circulación sanguínea. Contrario a lo que pudiera pensarse, esta situación no es exclusiva de la vejez ya que puede presentarse, incluso, a partir de la segunda década de la vida

Structure-activity relationships of polyphenols to prevent lipid oxidation in pelagic fish muscle.

The influence of polymerization (number of monomers) and galloylation (content of esterified gallates) of oligomeric catechins (proanthocyanidins) on their effectiveness to prevent lipid oxidation in pelagic fish muscle was evaluated. Non-galloylated oligomers of catechin with diverse mean polymerization (1.9-3.4 monomeric units) were extracted from pine (Pinus pinaster) bark. Homologous fractions with galloylation ranging from 0.25 to <1 gallate group per molecule were obtained from grape (Vitis vinifera) and witch hazel (Hamamelis virginiana). The results showed the convenience of proanthocyanidins with medium size (2-3 monomeric units) and low galloylation degree (0.15-0.25 gallate group/molecule) to inhibit lipid oxidation in pelagic fish muscle. These optimal structural characteristics of proanthocyanidins were similar to those lately reported in fish oil-in-water emulsions using phosphatidylcholine as emulsifier. This finding suggests that the antioxidant behavior of polyphenols in muscle-based foods can be mimicked in emulsions prepared with phospholipids as emulsifier agents. The present data give relevant information to achieve an optimum use of polyphenols in pelagic fish muscle.