Evaluation of willow herb's (Epilobium angustofolium L.) antioxidant and radical scavenging capacities

The Impact of Solid-Phase Fermentation on Flavonoids, Phenolic Acids, Tannins and Antioxidant Activity in Chamerion angustifolium (L.) Holub (Fireweed) Leaves

At present, the consumption of medical plants and functional foods is growing across the whole world. Fireweed (Chamerion angustifolium (L.) Holub), an important medicinal plant that has various pharmacological effects (antioxidant, anti-inflammatory, anticancer and others), can improve the state of health and well-being and reduce the risk of various diseases. The aim of this work was to investigate polyphenols (flavonoids, phenolic acids and tannins) and antioxidant activity in fireweed leaves fermented for 24, 48 and 72 h in solid-phase fermentation under aerobic and anaerobic conditions. High-performance liquid chromatography (HPLC) for polyphenols and the spectrophotometric method based on quenching of stable colored radical (ABTS•+) for antioxidant activity determinations were used. The results showed that the highest amounts of total polyphenols, total flavonoids and tannin oenothein B in the dried matter were found after 72 h and the highest total phenolic acids after 48 h of anaerobic solid-phase fermentation. The highest antioxidant activity was found after 72 h of solid-phase fermentation under aerobic conditions.

Epilobium angustifolium L. as a Potential Herbal Component of Topical Products for Skin Care and Treatment-A Review

Epilobium angustifolium L. (EA) has been used as a topical agent since ancient times. There has been an increasing interest in applying EA as a raw material used topically in recent years. However, in the literature, there are not many reports on the comprehensive application of this plant to skin care and treatment. EA contains many valuable secondary metabolites, which determine antioxidant, anti-inflammatory, anti-aging, and antiproliferative activity effects. One of the most important active compounds found in EA is oenothein B (OeB), which increases the level of ROS and protects cells from oxidative damage. OeB also influences wound healing and reduces inflammation by strongly inhibiting hyaluronidase enzymes and inhibiting COX-1 and COX-2 cyclooxygenases. Other compounds that play a key role in the context of application to the skin are flavonoids, which inhibit collagenase and hyaluronidase enzymes, showing anti-aging and anti-inflammatory properties. While terpenes in EA play an important role in fighting bacterial skin infections, causing, among other things cell membrane, permeability increase as well as the modification of the lipid profiles and the alteration of the adhesion of the pathogen to the animal cells. The available scientific information on the biological potential of natural compounds can be the basis for the wider use of EA in skin care and treatment. The aim of the article is to review the existing literature on the dermocosmetic use of E. angustifolium.

The potential and outgoing trends in traditional, phytochemical, economical, and ethnopharmacological importance of family Onagraceae: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

The Onagraceae is a widely distributed family of flowering plants comprises about 17 genera and more than 650 species of herbs, shrubs, and trees. Onagraceae also common as willowherb family or evening primrose family is divided into two subfamilies; Ludwigioideae (mainly genus; Ludwigia) and Onagroideae. Family Onagraceae is characterized by its numerous traditional uses as treatment of hormonal imbalances, urinary system ailments, prostate health maintenance, and antimicrobial effects.

AIM OF THE STUDY

This review aims to introduce a holistic overview on the phytochemical composition, economical importance and ethnopharmacological value of different species of family Onagraceae.

MATERIALS AND METHODS

Literature review was performed using different data bases such as PubMed, Web of Science, Google Scholar and Reaxys searching for articles focused on phytochemical composition, bioactivity and ethnopharmacological history of Onagraceae species.

RESULTS

Different species of Onagraceae were reported to have a great variety of phytochemicals including flavonoids, tannins, phenolic acids, triterpenoids, saponins, and volatile/fixed oils. Onagraceae exhibited several health benefits and pharmacological activities including anti-inflammatory, antiarthritic and analgesic, antioxidant, cytotoxic, antidiabetic, and antimicrobial.

CONCLUSIONS

Family Onagraceae is an extremely important family with diverse phytochemical composition which enriches their pharmacological importance and hence it's commercial and economical value.

Corn starch and methylcellulose edible films incorporated with fireweed (Chamaenerion angustifolium L.) extract: Comparison of physicochemical and antioxidant properties

The properties of edible films derived from corn starch (CS) and methylcellulose (MC) supplemented with fireweed extract (FE; 0.0125-0.05% w/w) were analyzed. Due to their more crystalline structure, the MC films were significantly stronger (~26 MPa) than the CS films (~4 MPa). In turn, CS produced films with lower water vapor permeability (WVP, 50.12-51.74 vs. 56.52-59.10 g mm m^-2 d^-1 kPa^-1). The hydrothermally-disrupted starch granules contributed to high roughness and opacity of the CS films. The FE-supplemented films exhibited an intensive yellow color and improved the UV-absorbing effect. FE delayed starch retrogradation, as indicated by the reduced crystallinity and slightly improved transparency of the CS films. Incorporation of FE significantly enhanced the released radical scavenging activity (RSA) of the films, while did not affect the WVP and mechanical properties. Due to better FE-trapping capacity, the CS-based films exhibited lower antioxidant activity (RSA_60min = 2.21-19.75%) as compared to the MC counterparts (RSA_60min = 4.87-38.31%).

Heat Stress in Broiler Chickens and the Effect of Dietary Polyphenols, with Special Reference to Willow (Salix spp.) Bark Supplements-A Review

Over the last decade, there has been a growing interest in the use of a wide range of phytoadditives to counteract the harmful effects of heat stress in poultry. Willow (Salix spp.) is a tree with a long history. Among various forms, willow bark is an important natural source of salicin, β-O-glucoside of saligenin, but also of polyphenols (flavonoids and condensed tannins) with antioxidant, antimicrobial, and anti-inflammatory activity. In light of this, the current review presents some literature data aiming to: (1) describe the relationship between heat stress and oxidative stress in broilers, (2) present or summarize literature data on the chemical composition of Salix species, (3) summarize the mechanisms of action of willow bark in heat-stressed broilers, and (4) present different biological effects of the extract of Salix species in different experimental models.

Cosmetic and Dermatological Properties of Selected Ayurvedic Plant Extracts

Due to the constantly growing interest in ingredients of natural origin, this study attempts to evaluate the possibility of using extracts from three Ayurvedic plants in preparations for the care and treatment of skin diseases. Therefore, studies of antioxidant properties were carried out using DPPH and ABTS radicals, obtaining 76% and 88% of these radical scavenging, respectively. A significant decrease in the intracellular level of free radicals and an increase in the activity of the antioxidant enzyme-superoxide dismutase by almost 60% were also observed. In addition, the extracts were assessed for anti-inflammatory and anti-aging properties, obtaining over 70% inhibition of lipoxygenase activity and almost 40% of collagenase. Additionally, the cytoprotective properties of the obtained extracts on skin cells, keratinocytes and fibroblasts, were demonstrated. To assess the content of biologically active compounds, HPLC-electrospray ionization (ESI)-MS/MS multiple reaction monitoring (MRM) analyses were performed. The obtained results show that all three analyzed plants are a valuable source of biologically active substances with desired properties in the context of skin cell protection. Particularly noteworthy is the extract of Epilobium angustifolium L., for which the most promising results were obtained.

In Vitro Human Skin Penetration, Antioxidant and Antimicrobial Activity of Ethanol-Water Extract of Fireweed (Epilobium angustifolium L.)

Epilobium angustifolium L. is applied as an antiseptic agent in the treatment of skin diseases. However, there is a lack of information on human skin penetration of active ingredients with antioxidative potential. It seems crucial because bacterial infections of skin and subcutaneous tissue are common and partly depend on oxidative stress. Therefore, we evaluated in vitro human skin penetration of fireweed ethanol-water extracts (FEEs) by determining antioxidant activity of these extracts before and after penetration study using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and Folin-Ciocalteu methods. Microbiological tests of extracts were done. The qualitative and quantitative evaluation was performed using gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC-UV) methods. The in vitro human skin penetration using the Franz diffusion chamber was assessed. The high antioxidant activity of FEEs was found. Gallic acid (GA), chlorogenic acid (ChA), 3,4-dihydroxybenzoic acid (3,4-DHB), 4-hydroxybenzoic acid (4-HB), and caffeic acid (CA) were identified in the extracts. The antibacterial activities were found against Serratia lutea, S. marcescens, Bacillus subtilis, B. pseudomycoides, and B. thuringiensis and next Enterococcus faecalis, E. faecium, Streptococcus pneumoniae, Pseudomonas aeruginosa, and P. fluorescens strains. In vitro penetration studies showed the penetration of some phenolic acids and their accumulation in the skin. Our results confirm the importance of skin penetration studies to guarantee the efficacy of formulations containing E. angustifolium extracts.

Pharmacological properties of fireweed (Epilobium angustifolium L.) and bioavailability of ellagitannins. A review

Fireweed (Epilobium angustifolium L.) is a well-known medicinal plant traditionally used in the treatment of urogenital diseases, stomach and liver disorders, skin problems, etc. E. angustifolium extracts show anti-androgenic, antiproliferative, cytotoxic, antioxidant, anti-inflammatory, immunomodulatory, and antimicrobial activities. The unique combination of biological properties demonstrated by the results of some studies indicates that fireweed has a positive effect in benign prostatic hyperplasia (BPH) and potentially in the prostate cancer chemoprevention. However, the efficacy of E. angustifolium phytotherapy is still poorly tested in clinical trials, while numerous beneficial effects of extracts have been documented in the in vitro and in vivo tests. Fireweed is rich in polyphenolic compounds, particularly ellagitannins. Currently, polyphenols are considered to be modulators of beneficial gut microbiota. The literature data support the use of ellagitannins in the prostate cancer chemoprevention, but caution is advised due to the highly variable production of urolithins by the individual microbiota. A better understanding of the microbiota’s role and the mechanisms of its action are crucial for an optimal therapeutic effect. This paper aims to summarize and discuss experimental data concerning pharmacological properties of E. angustifolium and bioavailability of ellagitannins – important bioactive compounds of this plant.

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.

Inter-population and inter-organ distribution of the main polyphenolic compounds of Epilobium angustifolium

Rosebay willowherb (Epilobium angustifolium) contains large amounts of polyphenolic compounds, including tellimagrandin I-based oligomeric ellagitannins (ETs). The aim of this study was to assess the interpopulational and inter-organ variability of the polyphenol fingerprint of E. angustifolium. Seven ETs, 11 flavonol glycosides and neochlorogenic acid were quantified by UHPLC-DAD-ESI-QqQ-MS in the leaves, flowers and stem parts of plants from 10 populations. Total polyphenol content of leaves and flowers ranged from 150 to 200 mg/g dry wt, of which 90% was constituted by dimeric to heptameric ETs. Flowers contained, on average, 10% more oenothein B (dimeric ET) and 2 times less oenothein A (trimeric ET) than leaves. Tetrameric and pentameric ETs exhibited rather similar levels in leaves and flowers whereas hexameric and heptameric were 3-4 times more abundant in flowers than in leaves. Quercetin-3-O-rhamnoside, myricetin-3-O-rhamnoside and kaempferol-3-O-rhamnoside were specific to flower tissue and were absent from leaves. The inflorescence stem showed the highest content in total polyphenols with an average of 250 mg/g dry wt and contained remarkably large amounts of oenothein B and A. Polyphenol content steadily decreased along the inflorescence stem and reached its lowest level in the vegetative part of the stem. The interpopulational variability of most polyphenols was within a two- to threefold range across the 10 sampled populations. Myricetin-3-O-glucoside and myricetin-3-O-glucuronide, however, showed a more population-specific distribution with concentrations varying from 0 to 2.3 mg/g dry wt. Finally, this study showed that the levels of oenothein B and A in the plant are not interdependent but that their relative abundance is constant within a population.

Phytochemistry, pharmacology and traditional uses of different Epilobium species (Onagraceae): a review

ETHNOPHARMACOLOGICAL RELEVANCE

The Epilobium genus (willowherb) comprises of ca. 200 species of herbaceous plants distributed around the world. Infusions prepared form willowherbs have been traditionally used externally in skin and mucosa infections and in the treatment of benign prostate hyperplasia. Nowadays extracts from different Epilobium species are widely used by patients, however the lack of clinical studies does not allow to fully establish their efficacy. The present review summarizes published data on phytochemistry, ethnopharmacological use and pharmacological studies concerning willowherb species investigated throughout past few decades.

MATERIALS AND METHODS

Literature survey was performed using Scopus, PubMed, Web of Science and Reaxys databases looking for papers and patents focused on chemical composition and bioactivity of Epilobium species. Systematic research in ethnopharmacological literature in digitalized sources of academic libraries was also carried out.

RESULT

The chemical composition of different Epilobium species and their bioactivities are described. The detailed information on constituents isolated and detected by chromatographic methods is given. The studies show that polyphenols are main compounds occurring in Epilobium herb among which flavonoids, phenolic acids and tannins (oenothein B and oenothein A) are dominating constituents. The extracts and some isolated compounds from Epilobium sp. were shown to possess antimicrobial, anti-proliferative, anti-inflammatory, analgesic and antioxidative activities. Because many studies suggest that oenothein B as dominating constituent may be responsible for Epilobium sp. pharmacological effects, its documented bioactivities were also described.

CONCLUSIONS

The pharmacological studies performed on Epilobium justify the traditional use of this species in external and in gastrointestinal inflammations. As far as the treatment of benign prostate hyperplasia (BPH) is considered, in the literature, there are some reports indicating that Epilobium extracts have a beneficial effect for this disorder, but the number of in vitro studies is not sufficient and the in vivo studies are not conclusive or too preliminary to draw a final conclusion about the efficacy of Epilobium preparations. More in vitro, in vivo and clinical studies to confirm this mode of action are strongly needed. Epilobium's extracts have also documented antioxidative and potential anti-inflammatory properties. Oenothein B can be considered as responsible for some of Epilobium pharmacological properties. Because of the lack of clinical data further studies are needed to provide an evidence base for traditional uses of plant materials belonging to the Epilobium genus.

Willow bark extract increases antioxidant enzymes and reduces oxidative stress through activation of Nrf2 in vascular endothelial cells and Caenorhabditis elegans

Willow bark extract (WBE) is listed in the European Pharmacopoeia and has been traditionally used for treating fever, pain, and inflammation. Recent studies have demonstrated its clinical usefulness. This study investigated the antioxidative effects of WBE in human umbilical vein endothelial cells (HUVECs) and Caenorhabditis elegans. WBE prevented oxidative-stress-induced cytotoxicity of HUVECs and death of C. elegans. WBE dose-dependently increased mRNA and protein expression levels of the nuclear factor erythroid 2-related factor 2 (Nrf2) target genes heme oxygenase-1, γ-glutamylcysteine ligase modifier and catalytic subunits, and p62 and intracellular glutathione (GSH) in HUVECs. In the nematode C. elegans, WBE increased the expression of the gcs-1::green fluorescent protein reporter, a well-characterized target of the Nrf2 ortholog SKN-1, in a manner that was SKN-1-dependent. WBE increased intranuclear expression and DNA binding of Nrf2 and the activity of an antioxidant response element (ARE) reporter plasmid in HUVECs. WBE-induced expression of Nrf2-regulated genes and increased GSH levels in HUVECs were reduced by Nrf2 and p38 small interfering (si) RNAs and by the p38-specific inhibitor SB203580. Nrf2 siRNA reduced the cytoprotective effect of WBE against oxidative stress in HUVECs. Salicin, a major anti-inflammatory ingredient of WBE, failed to activate ARE-luciferase activity, whereas a salicin-free WBE fraction showed intensive activity. WBE induced antioxidant enzymes and prevented oxidative stress through activation of Nrf2 independent of salicin, providing a new potential explanation for the clinical usefulness of WBE.

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.