Phytochemical Analysis and Evaluation of Genotoxic, Antigenotoxic Effects in Bacterial Models, and Hypoglycemic Activity of Epilobium angustifolium L. with Bioguided Isolation of Active Compounds.

This study examined the effects of methanol extract and its sub-extracts from Epilobium angustifolium on α-glucosidase and α-amylase activity. Secondary metabolites and amino acids were quantified using LC-MS/MS. Dichloromethane sub-extract displayed the highest activity and was chosen for further investigation. Despite the widespread use of E. angustifolium, genotoxicity studies were conducted to assess its safety. Dichloromethane significantly inhibited α-glucosidase (IC50 =17.340 µg/mL), making it approximately 293 times more effective than acarbose. Six known compounds, including gallic acid (1), a mixture of quercetin-3-O-α-galactoside (2a) and quercetin-3-O-α-glucoside (2b), quercetin-3-O-α-glucuronic acid (3), quercetin-3-O-α-rhamnoside (4), and kaempferol-3-O-α-rhamnoside (5) were identified. Quercetin-3-O-α-rhamnoside exhibited the highest inhibition of α-glucosidase (IC50 =1735±85 µM), making it 3.70 times more effective than acarbose. Dichloromethane also showed significant antigenotoxic activity against mutagenesis induced by NaN3, 9-AA, 4-NPD, and MNNG. Gallic acid was found in the highest abundance (13253.6931 ng/mL) in the methanolic extract. Furthermore, L-Aspartic acid was the most concentrated amino acid (363.5620 nmol/mL) in the methanolic extract.

Biological Activity of an Epilobium angustifolium L. (Fireweed) Infusion after In Vitro Digestion.

The biological activity of an in vitro digested infusion of Epilobium angustifolium (fireweed) was examined in a model system of intestinal epithelial and colon cancer tissues. The content of selected phenolic compounds in the digested aqueous extract of fireweed was determined using HPLC-ESI-QTOF-MS/MS. Biological activity was examined using the human colon adenocarcinoma cell lines HT-29 and CaCo-2 and the human colon epithelial cell line CCD 841 CoTr. Cytotoxicity was assessed by an MTT assay, a Neutral Red uptake assay, May-Grünwald-Giemsa staining, and a label-free Electric Cell-Substrate Impedance Sensing cytotoxicity assay. The effect of the infusion on the growth of selected intestinal bacteria was also examined. The extract inhibited the growth of intestinal cancer cells HT-29. This effect can be attributed to the activity of quercetin and kaempferol, which were the most abundant phenolic compounds found in the extract after in vitro digestion. The cytotoxicity of the fireweed infusion was dose-dependent. The highest decrease in proliferation (by almost 80%) compared to the control was observed in HT-29 line treated with the extract at a concentration of 250 µg/mL. The fireweed infusion did not affect the growth of beneficial intestinal bacteria, but it did significantly inhibit E. coli. The cytotoxic effect of the fireweed extract indicates that it does not lose its biological activity after in vitro digestion. It can be concluded that the fireweed infusion has the potential to be used as a supporting agent in colon cancer therapy.

Bacterial Cellulose Membrane Containing Epilobium angustifolium L. Extract as a Promising Material for the Topical Delivery of Antioxidants to the Skin.

Bacterial cellulose membranes (BCs) are becoming useful as a drug delivery system to the skin. However, there are very few reports on their application of plant substances to the skin. Komagataeibacter xylinus was used for the production of bacterial cellulose (BC). The BC containing 5% and 10% ethanolic extract of Epilobium angustifolium (FEE) (BC-5%FEE and BC-10%FEE, respectively) were prepared. Their mechanical, structural, and antioxidant properties, as well as phenolic acid content, were evaluated. The bioavailability of BC-FESs using mouse L929 fibroblasts as model cells was tested. Moreover, In Vitro penetration through the pigskin of the selected phenolic acids contained in FEE and their accumulation in the skin after topical application of BC-FEEs was examined. The BC-FEEs were characterized by antioxidant activity. The BC-5% FEE showed relatively low toxicity to healthy mouse fibroblasts. Gallic acid (GA), chlorogenic acid (ChA), 3,4-dihydroxybenzoic acid (3,4-DHB), 4-hydroxybenzoic acid (4-HB), 3-hydroxybenzoic acid (3-HB), and caffeic acid (CA) found in FEE were also identified in the membranes. After topical application of the membranes to the pigskin penetration of some phenolic acid and other antioxidants through the skin as well as their accumulation in the skin was observed. The bacterial cellulose membrane loaded by plant extract may be an interesting solution for topical antioxidant delivery to the skin.

Isolation, Chemical Characterization and Antioxidant Activity of Pectic Polysaccharides of Fireweed (Epilobium angustifolium L.).

The aim of this study was to isolate pectins with antioxidant activity from the leaves of Epilobium angustifolium L. Two pectins, EA-4.0 and EA-0.8, with galacturonic acid contents of 88 and 91% were isolated from the leaves of E. angustifolium L. by the treatment of plant raw materials with aqueous hydrochloric acid at pH 4.0 and 0.8, respectively. EA-4.0 and EA-0.8 were found to scavenge the DPPH radical in a concentration-dependent manner at 17-133 µg/mL, whereas commercial apple pectin scavenged at 0.5-2 mg/mL. The antioxidant activity of EA-4.0 was the highest and exceeded the activity of EA-0.8 and a commercial apple pectin by 2 and 39 times (IC50-0.050, 0.109 and 1.961 mg/mL), respectively. Pectins EA-4.0 and EA-0.8 were found to possess superoxide radical scavenging activity, with IC50s equal to 0.27 and 0.97 mg/mL, respectively. Correlation analysis of the composition and activity of 32 polysaccharide fractions obtained by enzyme hydrolysis and anionic exchange chromatography revealed that the antioxidant capacity of fireweed pectins is mainly due to phenolics and is partially associated with xylogalacturonan chains. The data obtained demonstrate that pectic polysaccharides appeared to be bioactive components of fireweed leaves with high antioxidant activity, which depend on pH at their extraction.

Epilobium angustifolium L. Extracts as Valuable Ingredients in Cosmetic and Dermatological Products.

Epilobium angustifolium L. is a popular and well-known medicinal plant. In this study, an attempt to evaluate the possibility of using this plant in preparations for the care and treatment of skin diseases was made. The antioxidant, antiaging and anti-inflammatory properties of ethanolic extracts from Epilobium angustifolium (FEE) were assessed. Qualitative and quantitative evaluation of extracts chemically composition was performed by gas chromatography with mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). The total polyphenol content (TPC) of biologically active compounds, such as the total content of polyphenols (TPC), flavonoids (TFC), and assimilation pigments, as well as selected phenolic acids, was assessed. FEE was evaluated for their anti-inflammatory and antiaging properties, achieving 68% inhibition of lipoxygenase activity, 60% of collagenase and 49% of elastase. FEE also showed high antioxidant activity, reaching to 87% of free radical scavenging using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 59% using 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Additionally, in vitro penetration studies were performed using two vehicles, i.e., a hydrogel and an emulsion containing FEE. These studies showed that the active ingredients contained in FEE penetrate through human skin and accumulate in it. The obtained results indicate that E. angustifolium may be an interesting plant material to be applied as a component of cosmetic and dermatological preparations with antiaging and anti-inflammatory properties.

Epilobium angustifolium L. Essential Oil-Biological Activity and Enhancement of the Skin Penetration of Drugs-In Vitro Study.

Epilobium angustifolium L. is a popular medicinal plant found in many regions of the world. This plant contains small amounts of essential oil whose composition and properties have not been extensively investigated. There are few reports in the literature on the antioxidant and antifungal properties of this essential oil and the possibility of applying it as a potential promoter of the skin penetration of drugs. The essential oil was obtained by distillation using a Clavenger type apparatus. The chemical composition was analyzed by the GC-MS method. The major active compounds of E. angustifolium L. essential oil (EOEa) were terpenes, including α-caryophyllene oxide, eucalyptol, ß-linalool, camphor, (S)-carvone, and ß-caryophyllene. The analyzed essential oil was also characterized by antioxidant activity amounting to 78% RSA (Radical Scavenging Activity). Antifungal activity against the strains Aspergillus niger, A. ochraceus, A. parasiticum, and Penicillium cyclopium was also determined. The largest inhibition zone was observed for strains from the Aspergillus group. The EOEa enhanced the percutaneous penetration of ibuprofen and lidocaine. After a 24 h test, the content of terpene in the skin and the acceptor fluid was examined. It has been shown that the main compounds contained in the essential oil do not penetrate through the skin, but accumulate in it. Additionally, FTIR-ATR analysis showed a disturbance of the stratum corneum (SC) lipids caused by the essential oil application. Due to its rich composition and high biological activity, EOEa may be a potential candidate to be applied, for example, in the pharmaceutical or cosmetic industries. Moreover, due to the reaction of the essential oil components with SC lipids, the EOEa could be an effective permeation enhancer of topically applied hydrophilic and lipophilic drugs.

Epilobium spp: Pharmacology and Phytochemistry.

The Epilobium species and their extracts are very popular in folk medicine, for a wide range of applications. The purpose of this review is the analysis of the pharmacological properties of Epilobium spp, considering whether their effects (e.g., anti-inflammatory, antioxidant, antitumor, antimicrobial, analgesic, and antiandrogenic) could rationally justify the use of Epilobium as a treatment of numerous diseases. Even if numerous preclinical studies have been reported, randomized controlled clinical trials (for the evaluation of safety and efficacy), and eventually cost-effectiveness studies (to estimate the long-term cumulative costs), are still needed to confirm the usefulness of these medicinal plants in human diseases.

Evaluation of the Effect of Epilobium angustifolium Aqueous Extract on LNCaP Cell Proliferation in In Vitro and In Vivo Models.

Epilobium sp. are commonly used in traditional medicine in the treatment of early stages of benign prostatic hyperplasia and inflammation. It is suggested that a dominating constituent, oenothein B, is responsible for the extracts therapeutic effects. Several bioactivities were established for extracts and oenothein B in various in vitro models, but due to the questionable bioavailability of this dimeric macrocyclic ellagitannin, their significance in the in vivo effects remains unresolved. We have thus focused our attention on a complex comparative investigation of the in vitro and in vivo activities of phytochemically characterized Epilobium angustifolium aqueous extract and oenothein B on prostate cancer cells proliferation.Incubation of different cell lines with E. angustifolium aqueous extract resulted in a significant reduction of proliferation of PZ-HPV-7 and LNCaP cells, which was partly associated with antiandrogenic activity. These effects were fully congruent with oenothein B, examined in parallel. Oral supplementation of rats implanted with LNCaP cells with E. angustifolium aqueous extract 50-200 mg/kg b. w. resulted in a reduction of the occurrence of prostatic adenoma up to 13 %. Oenothein B was not detected in the urine and feces of the E. angustifolium aqueous extract-treated group, however, conjugates of nasutins gut microbiota metabolites of ellagitannins were detected in the urine, while in human volunteers supplemented with Epilobium tea, only urolithin conjugates were present.Despite observing significant and consistent effects in vitro and in vivo, we were unable to point out unequivocally the factors contributing to the observed E. angustifolium aqueous extract activity, facing the problems of an unknown metabolic fate of oenothein B and interspecies differences in E. angustifolium aqueous extract gut microbiota metabolism.

New targets in the battle against dandruff.

Dandruff is a scalp disorder characterized by flaking skin and itch of an excessive oily scalp skin. It affects 55% of the global youth and adult population. Seborrheic dermatitis is a similar scalp skin disorder with aggravated itchy rashes and flaking. Different factors are identified in the dandruff development: increased sebum production, uncontrolled fungal growth of Malassezia strains and individual reaction to pro-inflammatory environment, and the susceptibility to trigger an immunological response. Using in vitro and ex vivo models, we show that an Epilobium angustifolium extract dose dependently reduces lipid synthesis in sebocytes to a maximum of -43% (1% extract), and protects the epidermis from Malassezia-induced morphological changes. Epilobium angustifolium extract also acts through innovative mechanisms involving regulations of defensins (human beta-defensins [hBD2] and hBD3) and toll-like receptor 2 involved in the immunological response of the skin. The anti-dandruff and sebum-regulating efficacy of E. angustifolium extract (1.5%) was confirmed in a clinical study that mobilized 24 volunteers with dandruff and greasy scalp for 30 days. At the end of the study, nonadherent and adherent dandruffs were significantly (p < 0.0001) reduced in average by -54% and -48%, respectively. Using Sebumeter® measurements, scalp sebum production was inhibited by -67% (p < 0.0001) in average over baseline. In conclusion, E. angustifolium extract offers a new innovative approach to dandruff reduction through immunomodulation of the skin response to Malassezia invasion.

Therapeutic Potential of Polyphenols from Epilobium Angustifolium (Fireweed).

Epilobium angustifolium is a medicinal plant used around the world in traditional medicine for the treatment of many disorders and ailments. Experimental studies have demonstrated that Epilobium extracts possess a broad range of pharmacological and therapeutic effects, including antioxidant, anti-proliferative, anti-inflammatory, antibacterial, and anti-aging properties. Flavonoids and ellagitannins, such as oenothein B, are among the compounds considered to be the primary biologically active components in Epilobium extracts. In this review, we focus on the biological properties and the potential clinical usefulness of oenothein B, flavonoids, and other polyphenols derived from E. angustifolium. Understanding the biochemical properties and therapeutic effects of polyphenols present in E. angustifolium extracts will benefit further development of therapeutic treatments from this plant. Copyright © 2016 John Wiley & Sons, Ltd.

[Investigation of metal element content of some European and Far Eastern herbs]. / Európai és távol-keleti gyógynövények és kivonatok fémelemtartalom-vizsgálata.

INTRODUCTION: Metal elements and their excess intake have significant influence on general health. AIM: There is only little information how Far Eastern herbs resemble European's regarding their purity and essential metal element content. The aim of the authors was to determine metal elements in different Chinese and European herbs and extracts. METHOD: The studied European herbs included Calendula officinalis petals, Achillea millefolium, Epilobium parviflorum herba, Urtica dioica leaves, Crataegus monogyna flowers while Far Eastern herbs were Cordyceps sinensis, Ganoderma lucidum, Ginkgo biloba leaves, Panax ginseng and Curcuma longa roots. The analysis was performed using inductively coupled plasma optical emission spectroscopy. RESULTS: There was no considerable difference in essential metal elements and the Ca:Mg concentration ratio between European and Far Eastern drugs and extracts. CONCLUSIONS: The extracts are preferential metal element sources and their magnesium content are also advantageous, because of a shift of the Ca:Mg concentration ratio towards magnesium.

Determination of phenolic acids in plant extracts using CZE with on-line transient isotachophoretic preconcentration.

A novel transient ITP-CZE for preconcentration and determination of seven phenolic acids (caffeic acid, cinnamic acid, p-coumaric acid, ferulic acid, protocatechuic acid, syringic acid, and vanilic acid) was developed and validated. Effects of several factors such as control of EOF, pH and buffer concentration, addition of organic solvents and CDs, and conditions for sample injection were investigated. Sample self-stacking was applied by means of induction of transient ITP, which was realized by adding sodium chloride into the sample. The CZE was realized in 200 mM borate buffer ((w)(s)pH 9.2) containing 37.5% methanol, 0.001% hexadimethrine bromide, and 15 mM 2-hydroxypropyl-ß-CD. Under the optimal conditions for analysis, analytes were separated within 20 min. Linearity was tested for each compound in the concentration range of 0.1-10 µg/mL (R = 0.9906-0.9968) and the detection limits (S/N = 3) ranged from 11 ng/mL (protocatechuic acid) to 31 µg/mL (syringic acid). The validated method was applied to the ethanolic extract of Epilobium parviflorum, Onagraceae. The method of SPE was used for the precleaning of the sample.

Extracts from Epilobium sp. herbs, their components and gut microbiota metabolites of Epilobium ellagitannins, urolithins, inhibit hormone-dependent prostate cancer cells-(LNCaP) proliferation and PSA secretion.

Extracts from Epilobium sp. herbs have been traditionally used in the treatment of prostate-associated ailments. Our studies demonstrated that the extracts from Epilobium angustifolium, Epilobium parviflorum and Epilobium hirsutum herbs are potent prostate cancer cells (LNCaP) proliferation inhibitors with IC50 values around 35 µg/ml. The tested extracts reduced prostate specific antigen (PSA) secretion (from 325.6 ± 25.3 ng/ml to ~90 ng/ml) and inhibited arginase activity (from 65.2 ± 1.1 mUnits of urea/mg of protein to ~40 mUnits of urea/mg protein). Selected constituents of extracts (oenothein B, quercetin-3-O-glucuronide, myricetin-3-O-rhamnoside) were proven to be active in relation to LNCaP cells. However, oenothein B was the strongest inhibitor of cells proliferation (IC50 = 7.8 ± 0.8 µM), PSA secretion (IC50 = 21.9 ± 3.2 µM) and arginase activity (IC50 = 19.2 ± 2.0 µM). Additionally, ellagitannins from E. hirustum extract were proven to be transformed by human gut microbiota into urolithins. Urolithin C showed the strongest activity in the inhibition of cell proliferation (IC50 = 35.2 ± 3.7 µM), PSA secretion (reduced PSA secretion to the level of 100.7 ± 31.0 ng/ml) and arginase activity (reduced to the level of 27.9 ± 3.3 mUnits of urea/mg of protein). Results of the work offer an explanation of the activity of Epilobium extracts and support the use of Epilobium preparations in the treatment of prostate diseases.

Epilobium angustifolium extract demonstrates multiple effects on dermal fibroblasts in vitro and skin photo-protection in vivo.

Stress-induced fibroblast senescence is thought to contribute to skin aging. Ultraviolet light (UV) radiation is the most potent environmental risk factor in these processes. An Epilobium angustifolium (EA) extract was evaluated for its capacity to reverse the senescent response of normal human dermal fibroblasts (NHDF) in vitro and to exhibit skin photo-protection in vivo. The HPLC-UV-MS analysis of the EA preparation identified three major polyphenol groups: tannins (oenothein B), phenolic acids (gallic and chlorogenic acids) and flavonoids. EA extract increased the cell viability of senescent NHDF induced by serum deprivation. It diminished connective tissue growth factor and fibronectin gene expressions in senescent NHDF. Down-regulation of the UV-induced release of both matrix metalloproteinase-1 and -3 and the tissue inhibitor of matrix metalloproteinases-1 and -2, and also down-regulation of the gene expression of hyaluronidase 2 were observed in repeatedly UV-irradiated NHDF after EA extract treatment. Interestingly, EA extract diminished the down-regulation of sirtuin 1 dampened by UV-irradiation. The application of EA extract using a sub-irritating dose protected skin against UV-induced erythema formation in vivo. In summary, EA extract diminished stress-induced effects on NHDF, particularly on connective tissue growth factor, fibronectin and matrix metalloproteinases. These results collectively suggest that EA extract may possess anti-aging properties and that the EA polyphenols might account for these benefits.

Epilobium hirsutum alters xenobiotic metabolizing CYP1A1, CYP2E1, NQO1 and GPx activities, mRNA and protein levels in rats.

CONTEXT: Natural products have attracted increasing interests due to their use in flavoring, nutrition, cosmetics, pharmacy and medicine. Epilobium hirsutum L. (Onagraceae) is known for its analgesic, antimicrobial, and antiproliferative activity. CYP1A1 and CYP2E1, xenobiotic metabolizing enzymes, serve as a metabolic activation route yielding reactive metabolites that are eliminated by the action of NQO1 and glutathione peroxidase (GPx) enzymes. OBJECTIVE: This study investigated in vivo effects of Epilobium hirsutum (EH) on CYP2E1, CYP1A1, NQO1 and GPx activities, protein and mRNA expressions in liver. MATERIALS AND METHODS: Male Wistar Albino rats were injected with EH at a dose of 37.5 mg/kg i.p. daily for 9 d. CYP2E1, CYP1A1, NQO1 and GPx activities, protein and mRNA levels were determined by enzyme assays, Western blotting and qPCR, respectively. RESULTS: CYP1A1 associated ethoxyresorufin-O-deethylase activity of control and EH-treated animals were found as 6.54 ± 1.21 and 4.48 ± 1.67 nmol/min/mg, respectively. CYP2E1 associated aniline 4-hydroxylase of control and EH group were 0.537 ± 0.011 and 0.109 ± 0.01 nmol/min/mg, respectively. However, EH treatment increased the GPx and NQO1 activities from 0.069 ± 0.015 to 0.107 ± 0.026 nmol/min/mg and from 163.34 ± 92 to 588.3 ± 14 nmol/min/mg, respectively. Furthermore, protein and mRNA expression analysis revealed that CYP1A1 and CYP2E1 levels were decreased while those of NQO1 and GPx increased after EH treatment. DISCUSSION AND CONCLUSION: Our current data suggest that the metabolism of xenobiotics, including drugs, may be altered due to changes in the expression and activity of these proteins by EH.

Determination of macrocyclic ellagitannin oenothein B in plant materials by HPLC-DAD-MS: method development and validation.

INTRODUCTION: Oenothein B (OeB) is a dimeric macrocyclic ellagitannin occurring mainly in the genus Oenothera. In the literature no validated HPLC method for quantification of this compound has been reported. OBJECTIVE: To develop and validate an efficient HPLC method for quantification of OeB in plant materials. METHODOLOGY: Extraction conditions of OeB from plant material were optimised. Then the first validated HPLC method for quantification was developed. RESULTS: We have shown that ultrasonic-assisted extraction at 40 °C in 15 min using water are the most optimal conditions for OeB extraction. We have quantified OeB in several plant materials belonging to Oenotheraceae family. The lowest amount of OeB was present in Circaea lutetiana herb (27.64 ± 0.26 mg/g) and the highest was quantified in Epilobium hirsutum aerial parts (72.91 ± 1.38 mg/g). CONCLUSION: The first HPLC method for quantification of OeB in plant materials was developed and validated. We also for the first time optimised the extraction conditions for OeB.

Evaluation of anticholinesterase effect of some Epilobium species and quantification of hyperoside by HPLC.

This article presents the evaluation of anticholinesterase effects of aerial parts of Epilobium angustifolium, E. stevenii and E. hirsutum and isolated flavonoids from E. angustifolium, and quantification of the flavonoids by HPLC. Besides, the highest acetylcholinesterase inhibition was seen in the EtOAc sub-extracts of E. angustifolium and E. stevenii (36.51 ± 1.88 and 39.89 ± 3.09%, respectively), whereas EtOAc sub-extract of E. angustifolium had the best butyrylcholinesterase inhibition (62.09 ± 1.98%). Hyperoside showed strong inhibition activity on both enzymes. The active EtOAc sub-extract of E. angustifolium was quantitatively analyzed for their content of hyperoside (quercetin-3-O-ß-D-galactoside) by HPLC. The content of hyperoside in EtOAc sub-extract of E. angustifolium was detected as 3.312%. The anatomical structures of the stem, leaf, sepal, petal, anther, and filament of E. angustifolium were investigated. The anatomical properties given in this study provide a description of E. angustifolium.[Formula: see text].

Effect of willow herb (Epilobium angustifolium L.) extract addition to canned meat with reduced amount of nitrite on the antioxidant and other activities of peptides.

The present study aimed to evaluate the effect of the addition of various amounts (50, 100, 150 and 1000 mg kg-1) of E. angustifolium L. extracts on the biological activity of peptides in canned meat with reduced amount of sodium nitrite and their stability during 180 days of storage (4 °C). The initial peptide data were collected by LC/MS. Antioxidant activities of peptide extracts were detected on the basis of ABTS˙*, FRAP, and iron(II) chelating activity in in vitro tests. A computational study (based on the BIOPEP-UWM database and INNOVAGEN, PeptideRanker and PROTPARAM tools) was also performed to assist in the interpretation of results. The addition of E. angustifolium L. extracts has a positive effect on the peptide profile and various biological activities, the results of which depend on the amount of the extract added to the meat product. However, it should be remembered that the differences between in silico and in vitro experimental environments necessitate further research to confirm the antioxidant behavior of canned meat products supplemented with E. angustifolium L. extract under physiological conditions. Other interactions between the peptide and the food matrix should also be considered as these can lead to chemical and structural modifications that can affect the bioavailability of the bioactive peptides.

Immunomodulatory activity of oenothein B isolated from Epilobium angustifolium.

Epilobium angustifolium has been traditionally used to treat of a number of diseases; however, not much is known regarding its effect on innate immune cells. In this study, we report that extracts of E. angustifolium activated functional responses in neutrophils and monocyte/macrophages. Activity-guided fractionation, followed by mass spectroscopy and NMR analysis, resulted in the identification of oenothein B as the primary component responsible for phagocyte activation. Oenothein B, a dimeric hydrolysable tannin, dose-dependently induced a number of phagocyte functions in vitro, including intracellular Ca(2+) flux, production of reactive oxygen species, chemotaxis, NF-kappaB activation, and proinflammatory cytokine production. Furthermore, oenothein B was active in vivo, inducing keratinocyte chemoattractant production and neutrophil recruitment to the peritoneum after intraperitoneal administration. Biological activity required the full oenothein B structure, as substructures of oenothein B (pyrocatechol, gallic acid, pyrogallol, 3,4-dihydroxybenzoic acid) were all inactive. The ability of oenothein B to modulate phagocyte functions in vitro and in vivo suggests that this compound is responsible for at least part of the therapeutic properties of E. angustifolium extracts.

Differences among Epilobium and Hypericum species revealed by four IR spectroscopy modes: transmission, KBr tablet, diffuse reflectance and ATR.

INTRODUCTION: Quality control of dried plant material in assessments of suitability of herbal medicinal products is of extreme importance. Commonly used procedures for identification of species are time consuming and expensive. The development of multivariate statistical methods has enabled application of vibrational spectroscopy for establishing plant species membership. OBJECTIVE: To determine which infrared spectroscopy mode gives most informative spectra for plant species identification. METHODOLOGY: Different modes of infrared spectroscopy were applied for investigation of differences among Epilobium and Hypericum species: diffuse reflectance (DR), attenuated total reflectance (ATR), direct transmission of whole leaves and KBr tablet transmission with comminuted leaves. The same chemometrical methods were applied to all spectra. The informative wave numbers were chosen by one-way analysis of variance. Afterwards the colinearity was reduced with principal component analysis. In the final step the species identification was determined with discriminant analysis. RESULTS: Transmission and diffuse reflectance mode did not give satisfactory results. Best results for discrimination among Epilobium species were obtained with ATR mode (98%), while best results for Hypericum species were obtained with KBr transmission mode (97%). This might be explained by the morphological properties of the two genera. Epilobium species differ in distribution and morphology of trichomes on the surface of the leaves. Hypericum species differ in structures and secondary metabolites in the interior of the leaves. CONCLUSION: For best results in using infrared spectroscopy for plant species identification in quality control, the morphological properties of plant material should be taken into consideration.