Antimicrobial DNA-binding Photosensitizers from the Common Rush, Juncus effusus¶

A Screen of Traditional Chinese Medicinal Plant Extracts Reveals 17 Species with Antimicrobial Properties

Background/Objectives: Antimicrobial resistance (AMR) is a growing threat that undermines the effectiveness of global healthcare. The Centers for Disease Control and Prevention and the World Health Organization have identified numerous microbial organisms, particularly members of the ESKAPEE pathogens, as critical threats to global health and economic security. Many clinical isolates of these pathogens have become completely resistant to current antibiotics, making treatment nearly impossible. Herbal remedies, such as those found in Traditional Chinese Medicine (TCM), have been practiced for thousands of years and successfully used to treat a wide range of ailments, including infectious diseases. Surprisingly, despite this extensive knowledge of folk medicine, no plant-derived antibacterial drugs are currently approved for clinical use. As such, the objective of this study is to evaluate the antimicrobial properties of extracts derived from TCM plants. Methods: This study explores a comprehensive library comprising 664 extracts from 132 distinct TCM plant species for antimicrobial properties against gram-negative (Escherichia coli) and gram-positive (Micrococcus luteus) bacteria using liquid and solid in vitro assays. Results: Intriguingly, our results reveal 17 plant species with potent antimicrobial properties effective primarily against gram-positive organisms, including Streptococcus aureus and epidermidis. A literature search revealed that nearly 100 purified compounds from the identified TCM plants were previously isolated and confirmed for their antimicrobial properties, collectively inhibiting 45 different bacterial species. Conclusions: Our results indicate that phytobiotics from the identified plants could serve as potential candidates for novel antimicrobials.

Antimicrobial potentials of natural products against multidrug resistance pathogens: a comprehensive review

Antibiotic resistance is one of the critical issues, describing a significant social health complication globally. Hence, the discovery of novel antibiotics has acquired an increased attention particularly against drug-resistant pathogens. Natural products have served as potent therapeutics against pathogenic bacteria since the glorious age of antibiotics of the mid 20th century. This review outlines the various mechanistic candidates for dealing with multi-drug resistant pathogens and explores the terrestrial phytochemicals isolated from plants, lichens, insects, animals, fungi, bacteria, mushrooms, and minerals with reported antimicrobial activity, either alone or in combination with conventional antibiotics. Moreover, newly established tools are presented, including prebiotics, probiotics, synbiotics, bacteriophages, nanoparticles, and bacteriocins, supporting the progress of effective antibiotics to address the emergence of antibiotic-resistant infectious bacteria. Therefore, the current article may uncover promising drug candidates that can be used in drug discovery in the future.

Estrogenic and anti-neutrophilic inflammatory phenanthrenes from Juncus effusus L

Juncus effusus L. (J. effusus) is a Traditional Chinese Medicine (TCM) that has long been used for dealing with gynaecological disorders, such as relieving insomnia, preventing tinnitus, reducing edema with diuretic effect. In our course of evidence-based medical research focused on this herb, one new phenanthrene, Junfusol B (2), together with seventeen known compounds were isolated and identified. All the structures of these compounds were elucidated by spectroscopic methods. The absolute stereochemistry of compounds 1 and 2 was further determined by comparing their calculated and experimental Electronic Circular Dichroism (ECD) spectra and optical rotation (OR) values. The isolates were evaluated for their estrogenic and anti-inflammatory activities which were considered as relevant etiological factors of insomnia, tinnitus and edema in the ancient TCM theory. The results revealed that most of the obtained phenanthrenes in this work were found exerting agonistic effects on estrogen receptor. This is the first report to declare the exact estrogen-regulating potential among this type of compounds from J. effusus. Moreover, phenanthrenes 3 - 7 exhibited significant inhibitions on superoxide anion generation and elastase release in fMLP/CB-induced human neutrophilic inflammation model. J. effusus may be developed as a complementary agent utilized in menopausal multiple syndromes.

Characterization and phylogenetic analysis of the complete chloroplast genome of Juncus effusus L

Juncus effusus L., a perennial herbaceous species of family Juncaceae, is distributed mainly in warm areas worldwide. We studied the complete chloroplast (cp) genome of J. effusus through next-generation sequencing technology. The whole cp genome contained 170,612 base pairs, with the GC ratio as 35.99%. The 70 genes annotated from the cp genome include 32 protein coding genes, eight rRNA genes and 30 tRNA genes. The genome’s large single-copy region (LSC) was 80,640 bp, with the small single-copy region (SSC) 64,718 bp, and inverted repeat (IR) 12,627 bp. Furthermore, a phylogenetic tree was generated to evaluate evolutionary relationship between J. effusus and relevant species. This study will be beneficial for the further understanding and application of J. effusus.

Dehydroeffusol inhibits hypoxia-induced epithelial-mesenchymal transition in non-small cell lung cancer cells through the inactivation of Wnt/β-catenin pathway

Dehydroeffusol (DHE) is a phenanthrene compound that possesses anti-tumor activity. However, the effect of DHE on non-small cell lung cancer (NSCLC) has not been investigated previously. Therefore, the objective of our study was to explore the role of DHE in NSCLC and the underlying mechanism. Our results showed that DHE significantly inhibited the cell viability of A549 cells in a dose- and time-dependent manner under normoxic condition. Moreover, A549 cells were more sensitive to DHE under hypoxic condition compared with the A549 cells cultured in normoxic condition. Hypoxia-induced increased migration and invasion abilities were mitigated by DHE in A549 cells. Treatment of DHE caused increased E-cadherin expression and decreased N-cadherin expression in hypoxia-induced A549 cells. DHE also suppressed hypoxia-induced increase in both protein and mRNA levels of hypoxia inducible factor-1α (HIF-1α) expression in A549 cells. Furthermore, DHE inhibited hypoxia-induced activation of Wnt/β-catenin pathway in A549 cells. The inhibitory effect of DHE on hypoxia-induced EMT was reversed by LiCl, which is an activator of Wnt/β-catenin signaling pathway. In conclusion, these findings demonstrated that DHE prevented hypoxia-induced EMT in NSCLC cells by inhibiting the activation of Wnt/β-catenin pathway, suggesting that DHE might serve as a therapeutic target for the NSCLC metastasis.

The Phytochemistry of Cherokee Aromatic Medicinal Plants

Background: Native Americans have had a rich ethnobotanical heritage for treating diseases, ailments, and injuries. Cherokee traditional medicine has provided numerous aromatic and medicinal plants that not only were used by the Cherokee people, but were also adopted for use by European settlers in North America. Methods: The aim of this review was to examine the Cherokee ethnobotanical literature and the published phytochemical investigations on Cherokee medicinal plants and to correlate phytochemical constituents with traditional uses and biological activities. Results: Several Cherokee medicinal plants are still in use today as herbal medicines, including, for example, yarrow (Achillea millefolium), black cohosh (Cimicifuga racemosa), American ginseng (Panax quinquefolius), and blue skullcap (Scutellaria lateriflora). This review presents a summary of the traditional uses, phytochemical constituents, and biological activities of Cherokee aromatic and medicinal plants. Conclusions: The list is not complete, however, as there is still much work needed in phytochemical investigation and pharmacological evaluation of many traditional herbal medicines.

Phenanthrenes from Juncus Compressus Jacq. with Promising Antiproliferative and Anti-HSV-2 Activities

Juncaceae species are rich sources of phenanthrenes. The present study has focused on the isolation and structure determination of biologically active components from Juncus compressus. Eleven compounds (nine phenanthrenes and two flavonoids) have been isolated from the plant by the combination of different chromatographic methods. Two compounds (compressins A (Compound 1) and B (Compound 2)) are novel natural products, while seven phenanthrenes (effusol (Compound 3), effususol (Compound 4), juncusol (Compound 5), 2-hydroxy-1-methyl-4-oxymethylene-5-vinyl-9,10-dihydrophenanthrene (Compound 6), 7-hydroxy-1-methyl-2-methoxy-5-vinyl-9,10-dihydrophenanthrene (Compound 7), effususin A (Compound 8), and dehydroeffusol (Compound 9)), and two flavonoids (apigenin (Compound 10) and luteolin (Compound 11) were isolated for the first time from the plant. Compressin B (Compound 2) is a dimeric phenanthrene, in which two juncusol monomers (Compound 5) are connecting through their C-3 atoms. The structure elucidation of the isolated compounds was carried out using 1D, 2D NMR spectroscopic methods and HR-MS measurements. In vitro investigation of the antiproliferative effect of the phenanthrenes on two cervical (HeLa and SiHa) and an ovarian human tumor cell line (A2780) revealed that compounds have remarkable antiproliferative activity, mainly on the HeLa cell line. Moreover, juncusol (Compound 5) proved to possess significant antiviral activity against the herpes simplex 2 virus (HSV-2).

Shotgun Proteomics and Quantitative Pathway Analysis of the Mechanisms of Action of Dehydroeffusol, a Bioactive Phytochemical with Anticancer Activity from Juncus effusus

Dehydroeffusol (DHE) is a phenanthrene isolated from the Chinese medicinal plant Juncus effusus. Biological evaluation of DHE reveals in vitro and in vivo anticancer effects. We performed a shotgun proteomic analysis using liquid chromatography-tandem mass spectrometry to investigate the changes in the protein profiles in cancer cells upon DHE treatment. DHE affected cancer-associated signaling pathways, including NF-κB, β-catenin, and endoplasmic reticulum stress. Through quantitative pathway and key node analysis of the proteomics data, activating transcription factor 2 (ATF-2) and c-Jun kinase (JNK) were found to be the key components in DHE's modulated biological pathways. Based on the pathway analysis as well as chemical similarity to estradiol, DHE is proposed to be a phytoestrogen. The proteomic, bioinformatic, and chemoinformatic analyses were further verified with individual cell-based experiments. Our study demonstrates a workflow for identifying the mechanisms of action of DHE through shotgun proteomic analysis.

Distribution and transfer of potentially toxic metal(loid)s in Juncus effusus from the indigenous zinc smelting area, northwest region of Guizhou Province, China

We collected samples (i.e., the aerial parts and roots of Juncus effusus and their growth media) in the indigenous zinc smelting area in the northwest region of Guizhou Province, China, and we measured and analyzed potentially toxic metal(loid)s (arsenic, As; cadmium, Cd; chromium, Cr; copper, Cu; mercury, Hg; lead, Pb and zinc, Zn) in these samples. The results include the following: First, there is a high concentration of one or more potentially toxic metal(loid)s in the slag and surrounding soil in the research area. This situation might be caused by metal(loid) damage or contamination due to the circumstances. Additionally, Juncus effusus in the indigenous zinc smelting area are contaminated by some potentially toxic metal(loid)s; since they are used for Chinese medical materials, it is especially significant that their As, Cd and Pb concentrations are greater than their limited standard values. Finally, both the bioconcentration factors and transfer factors for most potentially toxic metal(loid)s in Juncus effusus are less than 1 in the study area. Therefore, we suggest that Juncus effusus could be used for phytostabilization or as a pioneer plant for phytoremediation of potentially toxic metal(loid)s because it has a tolerance and exclusion mechanism for these metal(loid)s in the research district.

Phenanthrenes from Juncus inflexus with Antimicrobial Activity against Methicillin-Resistant Staphylococcus aureus

The present study has focused on an investigation of the antibacterial effects of Juncus inflexus and the isolation and identification of its active compounds. Eleven phenanthrenes were isolated from a methanolic extract of the roots. Four compounds (jinflexins A-D, 1-4) are new natural products, while seven phenanthrenes [juncuenins A (5), B (6), and D (8), juncusol (7), dehydrojuncuenins A (9) and B (11), and dehydrojuncusol (10)] were isolated for the first time from the plant. Jinflexin D (4) is a dimer with an unprecedented heptacyclic ring system. The absolute configurations of the new compounds were determined by TDDFT-ECD calculations, and their enantiomeric purity was checked by chiral HPLC analysis. Extracts of different polarity (n-hexane, dichloromethane, and ethyl acetate) were evaluated for their antimicrobial effects against methicillin-resistant Staphylococcus aureus, extended-spectrum β-lactamase (ESBL)-producing Citrobacter freundii, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, multiresistant Acinetobacter baumannii, and Pseudomonas aeruginosa. The MIC values of the isolated compounds were determined by a microdilution method. Jinflexin B (2), juncusol (7), juncuenin D (8), and dehydrojuncuenin B (11) showed significant activity (MIC value range 12.5-100 μg/mL) against MRSA strains.

Antibacterial screening of Juncaceae species native to the Carpathian Basin against resistant strains and LC-MS investigation of phenanthrenes responsible for the effect

The main objective of this project was to investigate the antibacterial activity of 19 species (Juncus acutus, J. alpinoarticulatus, J. articulatus, J. compressus, J. conglomeratus, J. effusus, J. filiformis, J. gerardii, J. inflexus, J. maritimus, J. monanthos, J. squarrosus, J. tenuis, J. trifidus, Luzula campestris, L. forsteri, L. luzuloides, L. sudetica and L. sylvatica) belonging to the family Juncaceae against methicillin-resistant S. aureus (MRSA), extended-spectrum β-lactamase (ESBL)-producing C. freundii, E. coli, E. cloacae, K. pneumoniae, and multiresistant A. baumannii and P. aeruginosa. Antibacterial susceptibilities were screened for inhibitory zones and MIC values determined by microdilution method. Among the tested extracts (n=96) 16 extracts prepared from Juncus species and 3 extracts from Luzula species showed mild to strong inhibitory activities against MRSA strains (inhibition zones=6.7mm-14.6mm; MIC values 9.75-156μg/mL). It can be concluded that Juncus and Luzula species demonstrated promising anti-MRSA effect, and J. maritimus, J. tenuis and J. gerardii considered worthy of activity-guided phytochemical investigations. The main bioactive constituents of Juncaceae species are phenanthrenes. Four phenanthrenes [juncuenin D (1), juncusol (2), dehydrojuncuenin B (3), and jinflexin B (4)] isolated previously from J. inflexus with anti-MRSA activity were investigated by LC-MS in extracts proved to be active in antimicrobial test.

Efficacy of a Juncus effusus extract on grapevine and apple plants against Plasmopara viticola and Venturia inaequalis, and identification of the major active constituent

BACKGROUND

There is growing demand to replace chemical pesticides with alternatives owing to concerns related to impacts on human health and the environment. Plant-derived plant protection products could provide sustainable and environmentally friendly alternatives to chemical products. The aim of this study was to identify plant and fungal extracts with so far unknown activity against important plant pathogens by in vitro screening of a library of more than 3000 extracts.

RESULTS

Several plant extracts with promising in vitro fungicidal activity (MIC100 ≤ 50 µg mL(-1) ) towards one or several of the investigated pathogens (Venturia ineaqualis, Phytophthora infestans, Plasmopara viticola) were identified by the screening. One of the hits, an ethyl acetate extract of Juncus effusus L. medulla, was further investigated, and dehydroeffusol (DHEF) was identified as its main active constituent. On susceptible grapevine and apple seedlings, efficacies of up to 100% were reached with the extract (EC50 123 or 156 µg mL(-1) ) and with DHEF (EC50 18 or 21 µg mL(-1) ) against P. viticola and V. inaequalis respectively.

CONCLUSIONS

Our results demonstrate that plants can provide promising alternatives for integrated and organic farming. J. effusus shows high efficacy at low concentrations and, as an abundant perennial species, is an interesting candidate for the development of a novel plant protection product. © 2015 Society of Chemical Industry.

Anti-inflammatory effects of Juncus effusus extract (JEE) on LPS-stimulated RAW 264.7 cells and edema models

CONTEXT

Juncus effusus L. var. decipiens BUCHEN. f. leschenaultii GAY has been used in traditional medicine for the treatment of anxiety and insomnia.

OBJECTIVE

The objective of this study was to evaluate the effects of ethanol extract from the pith of Juncus effusus (JEE) on anti-inflammatory activities in RAW 264.7 cells.

MATERIALS AND METHODS

The production of inflammatory mediators and the underlying mechanisms using 3.1, 6.3, and 12.5 μg/mL concentrations of JEE were investigated. In addition, the topical anti-inflammatory effects of JEE (0.5, 1, and 2 mg/mL) on 12-O-tetradecanoylphorobol-13 acetate (TPA)-induced ear edema and oral administration of JEE (50, 100, and 200 mg/kg) on carrageenan-induced paw-edema were studied in mice.

RESULTS

JEE reduced the release of nitric oxide (NO, IC50 value = 1.98 μg/mL), prostaglandin E2 (IC50 value = 5.5 μg/mL), and pro-inflammatory cytokines, IL-1β (IC50 value = 4.74 μg/mL) and IL-6 (IC50 value = 20.48 μg/mL). JEE also suppressed the protein expression of inducible NO synthase and cyclooxygenase-2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Mechanism studies showed attenuation of LPS-induced activation of NF-κB by JEE via abrogation of IκBα degradation and a subsequent decrease in nuclear p65 level. Phosphorylation of all three MAP kinases (ERK, JNK, and p38) in LPS-stimulated RAW 264.7 cells was also suppressed in a dose-dependent manner. In acute inflammation models of mice, topical application (1 and 2 mg) and oral administration (50, 100, and 200 mg/kg) of JEE ameliorated TPA-induced ear edema and carrageenan-induced paw edema, respectively, in dose-dependent manners.

DISCUSSION AND CONCLUSION

These results indicate that JEE exhibited anti-inflammatory activities by suppressing the production of inflammatory mediators in LPS-stimulated RAW 264.7 cells and by attenuating edema in mice.

Antimicrobial and Biofilm Effects of Herbs Used in Traditional Chinese Medicine

Of the twenty-two components of tea decoctions commonly used to treat infections, only Scutellaria, Taraxacum, Tussilago and Glycyrrhiza exhibited antimicrobial activity. The activity, when present, was organism specific, i.e., anti- Staphylococcus aureus, including anti-MRSA activity under aerobic and/or anaerobic conditions. However, with the exception of Scutellaria, sub-inhibitory concentrations of the herbs exhibited a pattern of inducing enhanced production of biofilm.

Phenanthrenes from Juncus effusus with anxiolytic and sedative activities

Eight phenanthrenes, 7-carboxy-2-hydroxy-1-methyl-5-vinyl-phenanthrene (1); 2,7-dihydroxy-1-methyl-5-aldehyde-9,10-dihydrophenanthrene (2); dehydroeffusol (3); dehydrojuncusol (4); 7-carboxy-2-hydroxy-1-methyl-5-vinyl-9,10-dihydrophenanthrene (5); 8-carboxy-2-hydroxy-1-methyl-5-vinyl-9,10-dihydrophenanthrene (6); effusol (7) and juncusol (8), were isolated from the aerial part of Juncus effusus. Compounds 1 and 2 were identified as new constituents. Compounds 7 and 8 showed anxiolytic and sedative activities.

Phenanthrenoids from Juncus acutus L., new natural lipopolysaccharide-inducible nitric oxide synthase inhibitors

The novel natural product juncutol (1), 1,4,7-trimethyl-8,9-dihydro-4H-cyclopenta[def]phenanthrene-2,6-diol, along with the three related metabolites juncusol (2), dehydrojuncusol (3), and 6-hydroxymethyl-1-methyl-5-vinyl-9,10-dihydrophenanthrene-2-ol (4), were isolated from the rhizomes of Juncus acutus L. (Juncaceae) growing in Egypt. The structural identity of 1 was determined on the basis of spectroscopic analyses, including 2D NMR spectroscopy. The inhibitory effect of these natural products on the expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide-stimulated RAW264.7 macrophage cells was determined for the first time. The unprecedented symmetrical compound juncutol (1) was found to be the most potent inhibitor against the induction of the proinflammatory iNOS protein.