Characterization of the effect of Epilobium extracts on human cell proliferation

Antibacterial and Antimycotic Activity of Epilobium angustifolium L. Extracts: A Review

The aim of this work was to provide an overview of available information on the antibacterial and antifungal properties of Epilobium angustifolium extracts. A literature search of Scopus, PubMed/Medline, and Google Scholar for peer-reviewed articles published between January 2000 and June 2023 was undertaken. A total of 23 studies were eligible for inclusion in this review. Significant variation of antimicrobial activity depending on the tested species and strains, type of extract solvent, or plant organs utilized for the extract preparation was found. E. angustifolium extracts were active against both Gram-positive and Gram-negative bacteria and showed antimycotic effects against the fungi of Microsporum canis and Trichophyton tonsurans and the dermatophytes Arthroderma spp. Greater susceptibility of Gram-positive than Gram-negative bacteria to fireweed extracts was found. A strong antibacterial effect was recorded for Staphylococcus aureus, Bacillus cereus, Micrococcus luteus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii including multi-drug resistant strains. E. angustifolium extract might find practical application as an antimicrobial in wound healing, components of cosmetic products for human and animals, or as food preservatives.

Chemical Characterization and Biological Evaluation of Epilobium parviflorum Extracts in an In Vitro Model of Human Malignant Melanoma

Malignant melanoma is an aggressive type of skin cancer characterised by high metastatic capacity and mortality rate. On the other hand, Epilobium parviflorum is known for its medicinal properties, including its anticancer potency. In this context, we aimed to (i) isolate various extracts of E. parviflorum, (ii) characterize their phytochemical content, and (iii) determine their cytotoxic potential in an in vitro model of human malignant melanoma. To these ends, we utilized various spectrophotometric and chromatographic (UPLC-MS/MS) approaches to document the higher content of the methanolic extract in polyphenols, soluble sugars, proteins, condensed tannins, and chlorophylls -a and -b as opposed to those of dichloromethane and petroleum. In addition, the cytotoxicity profiling of all extracts was assessed through a colorimetric-based Alamar Blue assay in human malignant melanoma (A375 and COLO-679) as well as non-tumorigenic immortalized keratinocyte (HaCaT) cells. Overall, the methanolic extract was shown to exert significant cytotoxicity, in a time- and concentration-dependent manner, as opposed to the other extracts. The observed cytotoxicity was confined only to human malignant melanoma cells, whereas non-tumorigenic keratinocyte cells remained relatively unaffected. Finally, the expression levels of various apoptotic genes were assessed by qRT-PCR, indicating the activation of both intrinsic and extrinsic apoptotic cascades.

Epilobium Species: From Optimization of the Extraction Process to Evaluation of Biological Properties

Epilobium species are used in Romanian folk medicine as tinctures, tea, or tablets for ameliorating the symptoms of benign prostate hyperplasia (BPH), but scientific-based evidence is scarce for this species or other endemic plants of the same genus. Therefore, the aims of this research were to evaluate the phytochemical profile of five endemic Epilobium species (E. hirsutum L., E. parviflorum Schreb., E. palustre L. E. dodonaei Vill., and E. angustifolium L.) and to assess their in vitro biological activity. For enhanced recovery of polyphenols, a D-optimal experimental plan was developed using Modde software and the optimal working conditions were ultra-turrax-assisted extraction, for 8 min, with 30% ethanol in water. The optimized extracts were obtained from various plant parts and were further characterized by LC-MS analysis, with the major compound being oenothein B. All extracts demonstrated good antioxidant activity, evaluated by DPPH and TEAC assays. The most prominent antimicrobial potency of optimized extracts was displayed against Bacillus cereus, while against Gram-(+) bacteria, a moderate efficacy was observed. Furthermore, anti-cancer, anti-inflammatory, and antioxidant potential were assessed on normal fibroblasts and prostate carcinoma cell lines. From the evaluated optimized extracts, E. angustifolium aerial parts had the highest selectivity toward killing cancerous cells, followed by E. hirsutum aerial parts extract. For the antioxidant effect, E. hirsutum leaves and E. hirstum aerial parts extracts displayed the highest potency, decreasing ROS at the level observed for the positive control. The highest anti-inflammatory potential, based on the IL-6 and IL-8 levels, was displayed by E. dodonaei aerial parts and E. angustifolium leaves extracts. In conclusion, all five endemic species of Epilobium harvested from Romanian flora possess a diverse phytochemical composition, which supports complex biological activities.

Comparative Analysis of the Efficiency of Medicinal Plants for the Treatment and Prevention of COVID-19

The COVID-19 pandemic has once again prompted people to resort to the remedies of folk and alternative medicine. Medicinal plants, because of their chemical composition, pharmacological properties, and the action of biologically active substances, can stop and relieve the symptoms of the disease. The purpose of the work is a comparative flora analysis of medicinal plants to identify the most prospective plant and further production of a remedy for the avoidance, treatment, and rehabilitation of COVID-19. The search for prospective medicinal plants was performed by analyzing the literature in online databases: Web of Science, Scopus, Google Scholar, and PubMed, including official WHO media sites. According to recent studies related to COVID-19, a significant number of medicinal plants with anti-inflammatory, antiviral, and immunostimulatory effects have been identified. A comparative study of nine medicinal plants was conducted to determine the most suitable medicinal plant to treat coronavirus infection. According to the results of the comparative analysis, Chamaenerion angustifolium Seg. showed itself as the most prospective medicinal plant with the greatest pharmacological effect compared with other types of medicinal plants. Its therapeutic properties allow physiological relief of 18 symptoms of coronavirus infection. It is advisable to conduct further clinical trials for the treatment and rehabilitation of COVID-19 using preparations from this plant.

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.

Polyphenols, Antioxidant Activity and Volatile Compounds in Fermented Leaves of Medicinal Plant Rosebay Willowherb (Chamerion angustifolium (L.) Holub)

At present, the consumption of medical plants and functional foods is growing in the whole world. Rosebay willowherb (Chamerionangustifolium (L.) Holub) is 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 volatile compounds, polyphenols, and antioxidant activity in rosebay willowherb leaves fermented for 24 and 48 h in solid state fermentation under aerobic and anaerobic conditions. High-performance liquid chromatography (HPLC) for polyphenols and the spectrophotometric method for antioxidant activity determinations were used. To recognize and identify the leaves’ fragrances, electronic nose (Alpha M.O.S) measurement technology was used. The results showed that the highest amounts of total polyphenols in dried matter were after 48 h aerobic solid state fermentation (SSF). Antioxidant activity was higher under 48 h SSF compared to the control. The most abundant flavoring compound groups were esters, terpenes, and aldehydes. In unfermented leaves, (z)-3-hexen-1-ol, acetate, hexyl acetate, and trans-hex-2-enyl acetate prevailed, characterized by fragrances of greenery, flowers, and fruits. The undesired esters group compounds, ethyl butyrate and butyl acetate, with pungent odor, were detected after 48 h anaerobic SSF.

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.

Effect of Different Durations of Solid-Phase Fermentation for Fireweed (Chamerion angustifolium (L.) Holub) Leaves on the Content of Polyphenols and Antioxidant Activity In Vitro

Fireweed has recently been recognized as a plant with high antioxidant potential and phenolic content. Its leaves can be fermented to prepare an infusion with ideal antioxidant activity. The aim of this study was to investigate and to determine the influence of solid-phase fermentation of different durations on the variation of polyphenols in the leaves of fireweed. Laboratory experiments were conducted in 2017-2018. The leaves of fireweed, naturally growing, were fermented for different periods of time: not fermented (control) and fermented for 24 and 48 h. The evaluation of polyphenols and antioxidant activity in leaves was performed using high- performance liquid chromatography (HPLC). Additionally, principal component analysis was used to characterize differences in bioactive compounds between fireweed samples fermented at different durations. Solid-phase fermented leaves were characterized by higher contents of oenothein B, quercetin and benzoic acid but had lower contents of quercetin-3-O-rutinoside, luteolin and chlorogenic and gallic acids. Antioxidant activity in short- (24 h) and long-term (48 h) fermentation (compared to control) gave the highest level of regression in 2017, but in 2018 the effect was observed only with short-term fermentation and control. In conclusion, solid-phase fermentation can be used to modulate biologically active compounds in fireweed leaves.

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.

Development and Validation of a HPLC-UV Method for the Evaluation of Ellagic Acid in Liquid Extracts of Eugenia uniflora L. (Myrtaceae) Leaves and Its Ultrasound-Assisted Extraction Optimization

A simple HPLC-UV method has been developed and validated for the quantification of ellagic acid (EA) in ethanol extracts of Eugenia uniflora L. (Myrtaceae) leaves. The ultrasound-assisted extraction (UAE) optimization was performed using a Box Behnken design (3³) combined with response surface methodology to study the effects of the ethanol concentration (%, w/w), extraction time (minutes), and temperature (°C) on the EA concentration. The optimized results showed that the highest extraction yield of EA by UAE was 26.0 μg mL⁻¹ when using 44% (w/w) ethanol as the solvent, 22 minutes as the extraction time, and 59°C as the extraction temperature. The concentration of EA in relation to the predicted value was 93.7%  ±  0.4. UAE showed a strong potential for EA extraction.

Analysis of antiproliferative effect of Chamerion angustifolium water extract and its fractions on several breast cancer cell lines

PURPOSE

To evaluate the antiproliferative effect of the aerial part of Chamerion angustifolium (L.) Holub. (Onagraceae) extract and its fractions in vitro. This is the first study on the anti-proliferative effect of C. angustifolium on 3 distinct breast cancer cell lines.

MATERIAL/METHODS

Breast cancer cell lines MCF7, MDA-MB-468 and MDA-MB-231 were exposed to different concentrations of the water extract of C. angustifolium, where DPPH radical scavenging activity was 0.018-0.443mg/ml, expressed in rutin equivalents. Cell growth was analyzed after 24, 48 and 72h of incubation. Solid-phase extraction was applied for the fractionation of C. angustifolium water extract and MDA-MB-468 cell line growth was tested using different fractions.

RESULTS

The concentrations corresponding to radical scavenging activity of 0.117 and 0.266mg/ml caused MCF7 cells growth inhibition, while in the samples exposed to the highest concentration (0.355 and 0.443mg/ml) no proliferation was register, suggesting cell death. MDA-MB-468 cell analysis showed similar responses. MDA-MB-231 demonstrated cell growth inhibition following the exposure to all analyzed high extract doses (0.117-0.443mg/ml). MDA-MB-468 cells were selected to evaluate the effect of fractions. In the samples exposed to the fraction containing the highest amount (91%) of oenothein B, at the concentration of 0.117mg/ml a pronounced cell growth inhibition while at higher concentrations (0.266 and 0.443mg/ml) no cell proliferation was observed.

CONCLUSIONS

The consumption of C. angustifolium herb can be advantageous, alongside with conventional breast cancer treatment.

Application of multi-shoots cultures in micropropagation of willow herb (Chamaenerion angustifolium (L.) Scop.)

Introduction: Willow herb (Chamaenerion angustifolium (L.) Scop. syn. Epilobium angustifolium L. from Onagraceae family is a valuable medicinal plant that has been used in the treatment of urogenital disorders including BPH (Benign Prostatic Hypertrophy). The raw material is a rich source of polyphenols as well as steroids, triterpenoids and fatty acids. Due to frequent interspecific hybridization, plants collected in wild display a very diverse and variable content of active compounds. This poses a challenge in obtaining high quality and homogenous raw material. Application of the in vitro cultures and micropropagation techniques may offer a solution for alternative methods of cultivation.

Objective: This work presents preliminary results of the first implementation of in vitro cultures of willow herb to obtain material for medicinal purposes.

Methods: Sterile seedlings were donors of explants, which were used for induction of multi-shoots culture according to a modified protocol described by Turker and co-workers. Statistical analysis was used for assessment of significance of differences among variables.

Results: Six different genotypes (lines) originating from root explants were chosen for clonal propagation. Efficiency of the elaborated method was 16–20 shoots per explant. Finally, over 3000 acclimatized plants were obtained and used for field crops.

Conclusions: The use of Ch. angustifolium in vitro cultures can contribute to the introduction of this valuable herb for field crops and increase the availability of the raw material for food and pharmaceutical industries.

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.

Epilobi Hirsuti Herba Extracts Influence the In Vitro Activity of Common Antibiotics on Standard Bacteria

Epilobium genus has been confirmed as an effective source of natural antimicrobials. However, the influence of Epilobi hirsuti herba derived products on usual antibiotics activity has not been studied. In this study, several standardized Epilobi hirsuti herba extracts (EHE) were evaluated in order to asses their potential effects on usual antibiotics tested on standard Gram-positive and Gram-negative bacterial strains in vitro. The results emphasized that the bacterial strains ranged from sensitive (MIC values between 50–200 μg GAE mL-1) (S. epidermidis ATCC 12228) to very resistant (E. coli strains), E. faecalis ATCC 29212 being practically immune to EHE. In terms of synergistic interaction, Tetracycline and Ampicillin combinations lead to the most important stimulatory effects, the diameters of the inhibition zone being even 60% bigger compared to the antibiotic alone. Synergistic effects between myricetin(galloyl) derivates and Tetracycline were also revealed on P. aeruginosa and E. coli strains. Together, it clearly demonstrated not only EHE’s own antimicrobial properties, but also their capacity to influence the antimicrobial potency of some common antibiotics. These results could be useful for the area of herbal medicines and as potential candidates in managing microbial resistance, but also for physicians and pharmacists using combined antibacterial therapy.

Cytotoxicity of medicinal plants of the West-Canadian Gwich׳in Native Americans towards sensitive and multidrug-resistant cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional medicine of the Native Americans has a long tradition of medicinal plants, which also influenced modern oncology. For instance, podophyllotoxin the active ingredient of Podophyllum peltatum L. (Berberidaceae) used by Native Americans to treat warts led to the development of etoposide and teniposide. In the present investigation, we studied 10 medicinal plants used by the Gwich׳in First Nation of West-Canada, which have been used against diverse diseases including cancer.

MATERIAL AND METHODS

Sensitive and multidrug-resistant (MDR) tumor cell lines expressing various ATP-binding cassette (ABC) transporters (P-glycoprotein/ABCB1/MDR1, MRP1/ABCC1, or BCRP/ABCG2) have been used. Cytotoxicity was determined by the resazurin assay.

RESULTS

Arctium minus Bernh. (Asteraceae). Lysichiton americanus Hultén & St. John (Araceae), and Maianthemum dilatatum (Alph.Wood) A.Nelson & J.F.Macbr.(Asparagaceae) were cytotoxic with IC50 values ranging from 2.40 to 86.35 µg/mL. The MDR cell lines did not exert cross-resistance to these extracts.

CONCLUSION

As these medicinal plants of the West-Canadian Gwich׳in First Nation were not involved in classical drug resistance mechanisms and might therefore be valuable to bypass anticancer drug resistance in refractory tumors.

Content of phenolic compounds in wild populations of Epilobium angustifolium growing at different altitudes

CONTEXT

Flavonoids are regarded as essential ingredients for the anti-inflammatory activity of Epilobium angustifolium L. (Onagraceae). The metabolic profiles of medicinal plants vary aside from genetic determination due to the influence by external factors.

OBJECTIVES

This study evaluates the influence of altitudinal variation on the content of flavonoids in E. angustifolium in two consecutive growing periods.

MATERIALS AND METHODS

Aerial and herbaceous plant materials were collected at three different altitudes (800, 1000, and 1500 m) during two collection periods. Plant samples (11-13 samples per altitude and year) were extracted with methanol using accelerated solvent extraction (ASE). Identification and quantification of the constituents were achieved by chromatographic means of HPLC-PDA and LC-PDA-MS analyses.

RESULTS

Rising concentrations of flavonol 3-O-glycosides could be detected with increasing altitude. The content of the major compound, quercetin 3-O-glucuronide, ranged from 4.4 ± 2.05 (800 m) to 4.9 ± 1.03 (1000 m) and up to 6.6 ± 1.14 mg/g (1500 m). The total amount of flavonol 3-O-glycosides in 73 analyzed samples ranged from 10.7 ± 1.37 up to 17.3 ± 1.99 mg/g.

DISCUSSION

Quercetin-3-O-glucuronide can be considered as a potential marker for the increased production of flavonols in herbal parts of E. angustifolium at higher altitudinal levels.

CONCLUSION

The study confirms that environmental factors at higher altitude result in elevated levels of flavonols in aerial plant tissues of E. angustifolium. Specific factors for influencing the flavonoid content have to be clarified in further studies.

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.

Flavonoids of willow herb (Chamerion angustifolium (L.) Holub) and their radical scavenging activity during vegetation

PURPOSE

Willow herb has been traditionally used in folk medicine and currently it is a potential raw material for production of phytopharmaceuticals. The aim of this work was to determine the highest amount of flavonoids and the highest radical scavenging activity of willow herb, which was collected in different vegetation phases (intensive growing, bud, massive blooming, ripening of fruits (seeds) and the end of vegetation) and in different parts of the plant (blooms, leaves and stems).

MATERIAL/METHODS

Raw material was collected at Kaunas Botanical garden of Vytautas Magnus University. Willow herb was extracted using methanol/water mixture (75/25 v/v, %). Methanolic extracts were purified using solid-phase extraction. For determination of the radical scavenging activity of compounds the HPLC system with the on-line post-column DPPH (1,1-diphenyl-2-picrylhydrazyl) radical reaction detection was used.

RESULTS

Five flavonoids were identified and their quantitative distribution and radical scavenging activity were evaluated. The highest total amount of flavonoids and radical scavenging activity were determined in willow herb collected during the massive blooming phase (11.12 ± 0.34 mg/g and 8.71 ± 0.29 mg/g, respectively).

CONCLUSIONS

The highest amount of flavonoids and radical scavenging activity was determined for raw material collected during the massive blooming phase. Evaluation of different parts of the plant during the massive blooming phase revealed that the highest amount of flavonoids and radical scavenging activity are characteristic for blooms of the plant.

Antimicrobial, antiparasitic, anti-inflammatory, and cytotoxic activities of Lopezia racemosa

The present study investigates the potential benefits of the Mexican medicinal plant Lopezia racemosa (Onagraceae). Extracts and fractions from aerial parts of this plant were assessed to determine their antibacterial, antifungal, antiparasitic, anti-inflammatory and cytotoxic activities in vitro. Aerial parts of the plant were extracted with various solvents and fractionated accordingly. Extracts and fractions were tested against a panel of nine bacterial and four fungal species. The antiparasitic activity was tested against Leishmania donovani, whereas the anti-inflammatory activity of the compounds was determined by measuring the secretion of interleukin-6 from human-derived macrophages. The same macrophage cell line was used to investigate the cytotoxicity of the compounds. Various extracts and fractions showed antibacterial, antifungal, antiparasitic, and anti-inflammatory activities. The hexanic fraction HF 11-14b was the most interesting fraction with antimicrobial, and anti-inflammatory activities. The benefit of L. racemosa as a traditional medicinal plant was confirmed as shown by its antibacterial, antifungal and anti-inflammatory activities. To the best of our knowledge, this is the first study reporting the biological activities of L. racemosa, including antiparasitic and anti-inflammatory activities.

Oenothein B suppresses lipopolysaccharide (LPS)-induced inflammation in the mouse brain

Oenothein B has been recently evaluated for its ability to affect inflammatory responses in peripheral tissues. In this study, we examined its effect on the damage to the central nervous system due to systemic inflammation. For this purpose, ICR mice were injected with an intraperitoneal (i.p.) dose of lipopolysaccharide (LPS; 1 mg/kg mouse). When oenothein B was administered per os (p.o.), it suppressed (1) LPS-induced abnormal behavior in open field; (2) LPS-induced microglial activation in the hippocampus and striatum; and (3) LPS-induced cyclooxygenase (COX)-2 production in the hippocampus and striatum of these mice. These results suggest that oenothein B had the ability to reduce neuroinflammation in the brain during systemic inflammation.

Extracts from Epilobium sp. herbs induce apoptosis in human hormone-dependent prostate cancer cells by activating the mitochondrial pathway

OBJECTIVES

The aim of this work was to determine the effect of standardized aqueous extracts from Epilobium angustifolium L., E. parviflorum Schreb. and E. hirsutum L. herbs on the apoptosis of hormone-dependent prostate cancer cells (LNCaP).

METHODS

The extracts were characterized using high-performance liquid chromatography-diode array detector coupled with mass spectrometry (HPLC-DAD-MS/MS). Apoptosis in the cells was analysed using Annexin V-fluorescein isothiocyanate, and mitochondrial potential, Δψm , using JC-1 by flow cytometry. Caspase-3 activity was determined by enzyme-linked immunosorbent assay.

KEY FINDINGS

Using the HPLC-DAD-MS/MS method, 38 constituents were characterized. Extracts contained significant amounts of oenothein B as well as flavonoids and phenolic acids. Exposure of LNCaP cells to the extracts (20, 50 and 70 μg/ml) resulted in a significant increase in the level apoptotic cells, from 2.86 ± 0.5% (for untreated cells) up to 86.6 ± 1.0%. All extracts significantly decreased the mitochondrial potential, Δψm , resulting in an increase in the activity of caspase-3 from 0.3 ± 0.07 ng/mg of protein (for untreated cells) up to 1.26 ± 0.32 ng/mg of protein.

CONCLUSIONS

This study demonstrated that Epilobium extracts are active against LNCaP prostate cancer cells and that their apoptotic activity is related to activation of the mitochondrial pathway. The high oenothein B content may influence the biological activity of these plant materials.

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.

A phase II randomised double-blind placebo-controlled clinical trial investigating the efficacy and safety of ProstateEZE Max: a herbal medicine preparation for the management of symptoms of benign prostatic hypertrophy

OBJECTIVE

The aim of the clinical trial was to evaluate the efficacy and safety of ProstateEZE Max, an orally dosed herbal preparation containing Cucurbita pepo, Epilobium parviflorum, lycopene, Pygeum africanum and Serenoa repens in the management of symptoms of medically diagnosed benign prostate hypertrophy (BPH).

DESIGN

This was a short-term phase II randomized double-blind placebo controlled clinical trial.

SETTING

The trial was conducted on 57 otherwise healthy males aged 40-80 years that presented with medically diagnosed BPH.

INTERVENTION

The trial participants were assigned to receive 3 months of treatment (1 capsule per day) with either the herbal preparation (n = 32) or a matched placebo capsule (n = 25).

OUTCOME MEASURES

The primary outcome measure was the international prostate specific score (IPSS) measured at baseline, 1, 2 and 3 months. The secondary outcomes were the specific questions of the IPSS and day-time and night-time urinary frequency.

RESULTS

There was a significant reduction in IPSS total median score in the active group of 36% as compared to 8% for the placebo group, during the 3-months intervention (p < 0.05). The day-time urinary frequency in the active group also showed a significant reduction over the 3-months intervention (7.0-5.9 times per day, a reduction of 15.6% compared to no significant reduction change for the placebo group (6.2-6.3 times per day) (p < 0.03). The night-time urinary frequency was also significantly reduced in the active group (2.9-1.8, 39.3% compared to placebo (2.8-2.6 times, 7%) (p < 0.004).

CONCLUSION

The herbal preparation (ProstateEZE Max) was shown to be well tolerated and have a significant positive effect on physical symptoms of BPH when taken over 3 months, a clinically significant outcome in otherwise healthy men.

Inhibition of NF-κB-dependent cytokine and inducible nitric oxide synthesis by the macrocyclic ellagitannin oenothein B in TLR-stimulated RAW 264.7 macrophages

Immunomodulatory effects of oenothein B (1), a macrocyclic ellagitannin from various Onagraceae species, have been described previously. However, the mechanisms underlying the anti-inflammatory activity of 1 have not been fully clarified. The effects of 1 were investigated on inducible nitric oxide synthase, TLR-dependent and TLR-independent signal transduction cascades, and cytokine expression using murine macrophages (RAW 264.7). Compound 1 (10-60 μg/mL) reduced NO production, iNOS mRNA, and iNOS protein levels in a dose-dependent manner, without inhibition of iNOS enzymatic activity. It reduced the binding of the NF-κB p50 subunit to the biotinylated-consensus sequence and decreased nuclear p65 translocation. Gallic acid as a subunit of the macrocyclic ellagitannin 1 showed a far lower inhibitory activity. Nitric oxide production was reduced by 1 after stimulation using TLR2 (Pam2CSK4) and TLR4 (Kdo2) agonists, but this compound did not inhibit inducible nitric oxide synthesis after stimulation using interferon-gamma. IL-1beta, IL-6, and TNF-alpha mRNA synthesis was clearly reduced by the addition of 1. Oenothein B (1) inhibits iNOS after stimulation with LPS, TLR2, and TLR4 agonists via inhibition of TLR/NF-κB-dependent inducible nitric oxide and cytokine synthesis independent from IFN-gamma/JAK/STAT pathways. The full molecular structure of this macrocyclic ellagitannin seems to be required for its immunomodulatory actions.

Gram-Negative and Gram-Positive Antibacterial Properties of the Whole Plant Extract of Willow Herb (Epilobium angustifolium)

The emergence of new pathogens and the increase in the number of multidrug-resistant strains in well-established pathogens during the past decade represent a growing public health concern globally. With the current lack of research and development of new antibiotics by large pharmaceutical companies due to poor financial returns, new alternatives need to be explored including natural herbal or plant-based extracts with reported antibacterial properties. Willow herb ( Epilobium angustifolium) preparations have been used in traditional aboriginal and folk medicine preparations externally as an antiphlogistic to treat prostate and gastrointestinal disorders and as an antiseptic to treat infected wounds. The authors hypothesized that a whole plant extract of willow herb would exhibit antimicrobial properties on a variety of both Gram-positive and gram-negative bacteria in culture. The authors found that, in comparison to growth controls, willow herb extract significantly inhibited the growth of Micrococcus luteus ( p < .01), Staphylococcus aureus ( p < .05), Escherichia coli ( p < .001), and Pseudomonas aeruginosa ( p < .001). They also found that willow herb extract inhibited the growth of bacteria in culture more effectively than vancomycin ( p < .05) or tetracycline ( p < .004). These results provide preliminary support for the traditional folkloric claim that the plant willow herb possesses antibacterial properties against a variety of gram-positive and gram-negative bacteria. Given that whole plant extract was utilized for this study, further investigations are warranted to determine which specific part of the plant (i.e., leaves, stem, roots, and flowers) possess the antibacterial properties.

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.

Antinociceptive activity of methanolic extract of Epilobium hirsutum

Antinociceptive activity of methanolic extract of aerial parts of Epilobium hirsutum (EH) was determined in the Hot plate and writhing tests in mice. Nearly all extracts showed a dose dependent and marked analgesic activity in mice in the thermal and chemical models of analgesia when compared to the control. Methanol extract at dose of 500 mg kg(-1) showed higher activity (97.7% writhing inhibition) than diclofenac 50 mg kg(-1) i.p., (77.8%, p<0.05) and morphine 5 mg kg(-1) i.p. (91.2%, p<0.05). Methanol extract, in all tested doses (200-500 mg kg(-1)) significantly increased the pain threshold in hot plate test (p<0.05). EH extract at 200 mg kg(-1) showed a similar effect to morphine at 5 mg kg(-1). These finding indicate the potential therapeutic use of methanolic extract of aerial parts of EH as a potent antinociceptive agent. LD50 was obtained 1.5+/-0.1 g kg(-1). EH extract did not induce locomotor impairment in mice at any tested doses.

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

The present study investigated the antioxidative properties of root, leaf and stalk of Epilobium angustofolium L. The activities of antioxidant enzymes (superoxide dismutase, catalase, peroxidase), quantities of malonyldialdehyde, superoxide and hydroxyl radicals and reduced glutathione and also the content of total flavonoids, chlorophylls a and b, carotenoids, vitamin C and soluble proteins were determined. The results indicate that extracts from all plant organs exhibited antioxidant activity. The highest antioxidant activity was observed in the leaves. Radical scavenging capacity (RSC), determined by DPPH assay, was highest in the leaves as well as total reducing power determined by FRAP assay. Lipofuscin 'plant age pigments' were also determined.

Inhibition of intestinal motility and secretion by extracts of Epilobium spp. in mice

Ethanol extracts of the fresh aerial parts of various Epilobium species were tested to elucidate the mechanism of their gastrointestinal activity in animals. The methods of charcoal meal, castor oil-induced diarrhoea, and enteropooling assay were used to evaluate their effect on mouse gut at various dose levels. The extracts were found to have a significant activity in all models. Moreover, the extracts resulted to possess very little toxicity. Thus, it can be concluded that Epilobium possesses anti-diarrhoeal, anti-motility, and anti-secretory activities and can prove beneficial in the treatment of gastrointestinal disorders.

Chemical composition and in vitro antioxidant evaluation of commercial water-soluble willow herb (Epilobium angustifolium L.) extracts

Five commercially available water-soluble extracts prepared from the aerial parts of Epilobium angustifolium L. (Onagraceae) were screened for antioxidant-related properties in a battery of six in vitro assays. Total phenol content and qualitative-quantitative analyses were also carried out. The extracts demonstrated varying degrees of efficacy in each screen. Two extracts, denoted as nonfermented and Tver, were the most effective toward reducing iron(III), scavenging 1,1-diphenyl-2-picrylhydrazyl free radicals, inhibiting hydroxyl radical-catalyzed bovine brain-derived phospholipid degradation, and non-site- and site-specific hydroxyl radical-catalyzed 2-deoxy-D-ribose degradation. The activity profile of the extracts changed, however, when their iron(II) chelating ability was assessed. The nonfermented and Tver extracts were not as effective iron(II) chelators as the extract denoted as Lotos. All the extracts contained Folin-Ciocalteu-reactive substances, which was confirmed by the presence of predominantly polar phenolic analytes (i.e., hydroxylated benzoic acid derivatives and flavonoids).

Induction of neutral endopeptidase activity in PC-3 cells by an aqueous extract of Epilobium angustifolium L. and oenothein B

An aqueous extract of Epilobium angustifolium and its main compound oenothein B (OeB), a dimeric macrocyclic ellagitannin, are specifically able to induce the neutral endopeptidase (NEP) in prostate cancer cells. The angiotensin-converting enzyme (ACE) is not influenced. Additionally, a weak but statistically significant inhibition of cell proliferation is observed. Simultaneous treatment of the cells with arabinosylcytosine and the extract as well as the OeB, leads to an additional enhancement of NEP activity. Taking into account the role of this peptidase in prostate cancer progression, our results might offer a pharmacological explanation for the use of Epilobium in folk medicine.