Comparative analysis of the main medicinal substances and applications of Echium vulgare L. and Echium plantagineum L.: A review

Soil pH, developmental stages and geographical origin differently influence the root metabolomic diversity and root-related microbial diversity of Echium vulgare from native habitats

Improved understanding of the complex interaction between plant metabolism, environmental conditions and the plant-associated microbiome requires an interdisciplinary approach: Our hypothesis in our multiomics study posited that several environmental and biotic factors have modulating effects on the microbiome and metabolome of the roots of wild Echium vulgare plants. Furthermore, we postulated reciprocal interactions between the root metabolome and microbiome. We investigated the metabolic content, the genetic variability, and the prokaryotic microbiome in the root systems of wild E. vulgare plants at rosette and flowering stages across six distinct locations. We incorporated the assessment of soil microbiomes and the measurement of selected soil chemical composition factors. Two distinct genetic clusters were determined based on microsatellite analysis without a consistent alignment with the geographical proximity between the locations. The microbial diversity of both the roots of E. vulgare and the surrounding bulk soil exhibited significant divergence across locations, varying soil pH characteristics, and within the identified plant genetic clusters. Notably, acidophilic bacteria were characteristic inhabitants of both soil and roots under acidic soil conditions, emphasizing the close interconnectedness between these compartments. The metabolome of E. vulgare significantly differed between root samples from different developmental stages, geographical locations, and soil pH levels. The developmental stage was the dominant driver of metabolome changes, with significantly higher concentrations of sugars, pyrrolizidine alkaloids, and some of their precursors in rosette stage plant roots. Our study featured the complex dynamics between soil pH, plant development, geographical locations, plant genetics, plant metabolome and microbiome, shedding light on existing knowledge gaps.

Phytochemical profile of petals from black Dahlia pinnata by flow injection analysis-electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry

INTRODUCTION

Dahlia pinnata Cav. is a flower native to Mexico that has many applications; in particular, its petals have been used for ornamental, food, and medicinal purposes, for example to treat skin rashes and skin cracks. It has been reported that the medicinal properties of plants are generally related to the phytochemical constituents they possess. However, there are few studies on black D. pinnata.

OBJECTIVES

The present study was aimed at qualitatively and quantitatively determining the phytochemical profile of petals from black D. pinnata.

METHODOLOGY

Phytochemicals from Dahlia petals were extracted by consecutive maceration (hexane, dichloromethane, and methanol); then, the extracts were analyzed through colorimetric assays and UV-Vis spectroscopy for qualitative identification and quantification of phytochemical compounds, respectively. The methanolic extract was analyzed by flow injection analysis-electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (FIA-ESI-FTICR-MS) in negative and positive mode.

RESULTS

Quantitative phytochemical profiling of the methanolic extract by UV-Vis spectroscopy indicated high contents of phenolic compounds (34.35 ± 3.59 mg EQ/g plant) and sugars (23.91 ± 1.99 mg EQ/g plant), while the qualitative profiling by FIA-ESI-FTICR-MS allowed the tentative identification of several flavonoids and phenolic acids. Kaempferol-3-rutinoside, pelargonidin-3-(6″-malonylglucoside)-5-glucoside, rutin, kaempferol-3-(2″,3″-diacetyl-4″-p-coumaroylrhamnoside), and myricetin-3-(2‴-galloylrhamnoside) were the main compounds detected.

CONCLUSION

The results expand our knowledge of the phytochemical constituents of petals from black D. pinnata.

Moringa oleifera Lam.: a comprehensive review on active components, health benefits and application

Moringa oleifera Lam. is an edible therapeutic plant that is native to India and widely cultivated in tropical countries. In this paper, the current application of M. oleifera was discussed by summarizing its medicinal parts, active components and potential mechanism. The emerging products of various formats such as drug preparation and product application reported in the last years were also clarified. Based on literature reports, the unique components and biological activities of M. oleifera need to be further studied. In the future, a variety of new technologies should be applied to the development of M. oleifera products, to enrich the varieties of dosage forms, improve the bitter taste masking technology, and make it better for use in the fields of food and medicine.

Echiumin E, an Aryl Dihydronaphthalene Lignan from the Australian Invasive Plant Paterson's Curse (Echium plantagineum)

A new aryl dihydronaphthalene lignan, echiumin E (1), and four known compounds, echiumin A, globoidnan A, (-)-rabdosiin, and rosmarinic acid (2-5), were isolated from the Australian invasive plant Echium plantagineum (Paterson's curse) for the first time. Echiumin E (1) was characterized by 1D/2D NMR spectroscopy and MS spectrometry, with its absolute configuration assigned through comparison of experimental and TDDFT-calculated ECD data. Echiumin E (1) along with compounds 3-5 were screened in vitro against three cancer cell lines (SH-SY5Y, HeLa, and PC-3) and a prostate stromal (normal) cell line (WPMY-1) using a resazurin reduction assay. Echiumin E (1) was found to be active toward HeLa cells (IC₅₀ 0.21 μM).

Echium vulgare and Echium plantagineum: A Comparative Study to Evaluate Their Inclusion in Mediterranean Urban Green Roofs

Green roofs (GRs) are proposed to offset against numerous environmental and socio-economic concerns associated with climate change and urban sprawl. In Mediterranean urban areas, to protect and conserve biodiversity through GRs, the use of native plant species from arid environments and with shallow roots is generally recommended. In north Europe, Echium vulgare L. is widely used on GRs for its tolerance to abiotic stresses and its attractiveness for bees; unfortunately, since this species requires cold winters to induce flowering and warm wet summers for vegetative growths, its adaptability to Mediterranean GRs has been questioned. The current study is based on the hypothesis that Echium plantagineum L. can adapt better to the Mediterranean environment than E. vulgare and offer blooms to pollinators, thus providing the important urban ecosystem service (UES) of protecting entomofauna biodiversity. To compare the adaptability of E. plantagineum vs. E. vulgare, both Echium species were grown and studied on the extensive GR installed at ENEA Casaccia Research Center, in the north of Rome, Lazio, Italy. The comparative analysis of the GR performance of the two species was based on several plant-related traits, including seed morphology, rosette stage, inflorescence, flower and root-related traits, and their biological life cycle, most of them showing significant differences (for example, rosette area was 1.42-fold major in E. plantagineum than in E. vulgare). The information provided in this manuscript will be useful to update the herbarium records for conservation biology. A dramatic water stress was purposely applied in the GR before the end of the hot summer season, and while E. plantagineum faced with success the imposed dehydration (88.4% vegetation cover), E. vulgare did not (7.5% vegetation cover), presumably because of its biennial life cycle which did not allow it to complete seed maturation (only 46.9% percentage mature seeds in E. vulgare respect to 89.5% in E. plantagineum). In summary, as the main result, this work shows that in Mediterranean areas, the inclusion of E. plantagineum in seed mixes for flower meadow GRs could represent a valuable alternative to E. vulgare in temperate areas, providing a safeguard for pollinators and allowing water and energy saving.

The complete plastome of Echium plantagineum L. (Boraginaceae), the first chloroplast genome belonging to the Echium genus

Besides being a common weed, the presence of Echium plantagineum L. in food and feed commodities can represent a safety hazard due to their content in pyrrolizidine alkaloids. In this study, the complete chloroplast of E. plantagineum isolate BPTPS251 is described, being the first available plastome from an isolate belonging to the Echium genus. The chloroplast genome is 149,776 bp in length with 37.5% GC content, displaying a quadripartite structure that contains a pair of inverted repeats regions (25,754 bp each), separated by a large single-copy (80,978 bp) and a small single-copy (17,290 bp) regions. A total of 131 genes were predicted, including 37 tRNA genes, 8 rRNA genes, and 86 protein-coding genes. The phylogenetic analysis confirmed the placement of E. plantagineum under the Boraginaceae family, belonging to the Boraginales order. This study will contribute to conservation, phylogenetic, and evolutionary studies, as well as DNA barcoding applications for food and feed safety purposes.

Isolation of Echimidine and Its C-7 Isomers from Echium plantagineum L. and Their Hepatotoxic Effect on Rat Hepatocytes

Echimidine is the main pyrrolizidine alkaloid of Echium plantagineum L., a plant domesticated in many countries. Because of echimidine’s toxicity, this alkaloid has become a target of the European Food Safety Authority regulations, especially in regard to honey contamination. In this study, we determined by NMR spectroscopy that the main HPLC peak purified from zinc reduced plant extract with an MS [M + H]+ signal at m/z 398 corresponding to echimidine (1), and in fact also represents an isomeric echihumiline (2). A third isomer present in the smallest amount and barely resolved by HPLC from co-eluting (1) and (2) was identified as hydroxymyoscorpine (3). Before the zinc reduction, alkaloids (1) and (2) were present mostly (90%) in the form of an N-oxide, which formed a single peak in HPLC. This is the first report of finding echihumiline and hydroxymyoscorpine in E. plantagineum. Retroanalysis of our samples of E. plantagineum collected in New Zealand, Argentina and the USA confirmed similar co-occurrence of the three isomeric alkaloids. In rat hepatocyte primary culture cells, the alkaloids at 3 to 300 µg/mL caused concentration-dependent inhibition of hepatocyte viability with mean IC50 values ranging from 9.26 to 14.14 µg/mL. Our discovery revealed that under standard HPLC acidic conditions, echimidine co-elutes with its isomers, echihumiline and to a lesser degree with hydroxymyoscorpine, obscuring real alkaloidal composition, which may have implications for human toxicity.