Himantoglossum robertianum (Loisel.) P. Delforge is a Mediterranean orchid whose propagation in vitro has been achieved, making it eligible as a source of bioactive substances. Flowers were analyzed by light and SEM microscopy and used to obtain a polyphenol-rich, hydroalcoholic flower extract (HFE). HFE was characterized for total phenols, flavonoids and proanthocyanidins, and for polyphenol profile by RP-LC-DAD. Antioxidant assays, in vitro collagenase and elastase inhibition, and MTT and cell motility assays on HaCaT keratinocytes were done. Microscopy showed epidermal cells containing anthocyanins in the flower labellum. Flavonoids (flavones and flavan-3-ols) represented the most abundant compounds (42.91%), followed by scopoletin (33.79%), and phenolic acids (23.3%). Antioxidant assays showed strong activities, rating ORAC > FRAP > TEAC > β-carotene bleaching > DPPH > iron-chelation. Biological assays showed elastase and collagenase inhibition (up to 42% and 78%, respectively), improvement of HaCaT cell viability after treatment with 500 μM H2O2 (from 30% to 84% of control), and stimulation of cell migration rate up to 210% of control. In summary, HFE counteracted different free radicals, while protective properties were shown by cell-free and cell-based bioassays, suggesting the possible use of H. robertianum flowers for skin-preserving, repair, and anti-aging applications.

Background: Fruit peels are generally underutilized byproducts of the food industry, although they are valuable sources of bioactive compounds. The aim of this study is to evaluate a new application for three Citrus peel EOs as bio-herbicides. Methods: After a micro-morphological evaluation of Citrus peels by SEM analysis, the phytochemical composition of the EOs of Citrus × bergamia Risso & Poit., Citrus × myrtifolia Raf., and Citrus limon (L.) Osbeck was characterized by GC/FID and GC/MS analyses. The in vitro phytotoxicity against germination and initial radical elongation of several crop and weed species was evaluated. Furthermore, the eco-compatibility of these EOs has been assessed by the brine shrimp (Artemia salina) lethality assay. Results: SEM analysis highlighted the morphometric differences of the schizolysigenous pockets among the peels of the three Citrus species. Oxygenated monoterpenes are the main constituents in C. × bergamia (51.09%), whereas monoterpene hydrocarbons represent the most abundant compounds in C. × myrtifolia (82.15%) and C. limon (80.33%) EOs. They showed marked and selective phytotoxic activity in vitro, often at very low concentration (0.1 μg/mL) against all plant species investigated, without showing any toxicity on Artemia salina, opening the perspective of their use as safe bio-herbicides.

Hybridization can often lead to the formation of novel taxa which can have traits that resemble either or both parental species. Determining the similarity of hybrid traits to parental taxa is particularly important in plant conservation, as hybrids that form between rare and common taxa may more closely resemble a rare parental species, thereby putting the rare parental taxon at further risk of extinction via increased backcrossing and introgression. We investigated the floral (morphological and chemical) traits and orchid mycorrhizal (OrM) fungal associations of the endangered orchid Orchis patens, its more common sister species O. provincialis, and their natural hybrid O. × fallax in natural sympatric populations. We found that both morphological and chemical floral traits of O. × fallax are shared by the parents but are more similar to O. patens than O. provincialis. OrM fungi were shared among all three taxa, indicating that the availability of OrM fungi should not represent a barrier to establishment of individuals of any of these taxa. These results suggest that O. × fallax may be able to expand its distribution within a similar niche to O. patens. This highlights the importance of quantifying differences between hybrids and parental taxon in species conservation planning.

A detailed chemical composition of Dendrobium essential oil has been only reported for a few main species. This article is the first to evaluate the essential oil composition, obtained by steam distillation, of five Indian Dendrobium species: Dendrobium chrysotoxum Lindl., Dendrobium harveyanum Rchb.f., and Dendrobium wardianum R.Warner (section Dendrobium), Dendrobium amabile (Lour.) O’Brien, and Dendrobium chrysanthum Wall. ex Lindl. (section Densiflora). We investigate fresh flower essential oil obtained by steam distillation, by GC/FID and GC/MS. Several compounds are identified, with a peculiar distribution in the species: Saturated hydrocarbons (range 2.19–80.20%), organic acids (range 0.45–46.80%), esters (range 1.03–49.33%), and alcohols (range 0.12–22.81%). Organic acids are detected in higher concentrations in D. chrysantum, D. wardianum, and D. harveyanum (46.80%, 26.89%, and 7.84%, respectively). This class is represented by palmitic acid (13.52%, 5.76, and 7.52%) linoleic acid (D. wardianum 17.54%), and (Z)-11-hexadecenoic acid (D. chrysantum 29.22%). Esters are detected especially in species from section Dendrobium, with ethyl linolenate, methyl linoleate, ethyl oleate, and ethyl palmitate as the most abundant compounds. Alcohols are present in higher concentrations in D. chrysantum (2.4-di-tert-butylphenol, 22.81%), D. chrysotoxum (1-octanol, and 2-phenylethanol, 2.80% and 2.36%), and D. wardianum (2-phenylethanol, 4.65%). Coumarin (95.59%) is the dominant compound in D. amabile (section Densiflora) and detected in lower concentrations (range 0.19–0.54%) in other samples. These volatile compounds may represent a particular feature of these plant species, playing a critical role in interacting with pollinators.

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Table S1. Morphometric and ponderal parameters on 20 individuals after 5 months from sowing (T0). Data were analyzed by ANOVA followed by Fisher's probable least-squares difference test with cut-off significance at p≤0.05 (four Petri dishes and 1600 seeds per species).

Mertensia maritima is a commercially interesting herb with edible leaves and flowers, characterized by oyster flavor and taste. Plant propagation and traditional cultivation are challenging for this species. Therefore, the main purpose of the present study was to establish successful protocols aimed at ensuring oyster plant shoot propagation, rooting and in vivo acclimatization. Both micropropagation and rooting were tested, comparing the traditional in vitro solid substrate in jar vs. the liquid culture in a temporary immersion system (TIS) bioreactor (Plantform™). A Murashige and Skoog (MS) medium added with 4-µM thidiazuron (TDZ) and 1-µM α-naphthaleneacetic acid (NAA) was employed for micropropagation, while a half-strength MS medium supplemented with 4-µM indole−3-butyric acid (IBA) was used for rooting. Different acclimatization conditions in the greenhouse or in growth chamber were tested. Morphometric and microscopical analyses were performed on the oyster plant leaves at the propagation, rooting and acclimatization stages both in a jar and in a TIS. Micropropagation in a TIS allowed to obtain large shoots, while a great number of shoots was observed in the jar. M. maritima shoots rooted in TIS produced more developed roots, leaves with more developed waxy glands and well-formed stomata; moreover, the plants coming from the TIS showed the best acclimatization performances.

Peucedanum ostruthium (L.) W. D. J. Koch (Apiaceae) is a worldwide perennial herb native to the mountains of central Southern Europe. The rhizome has a long tradition in popular medicine, while ethnobotanical surveys have revealed local uses of leaves for superficial injuries. To experimentally validate these uses, plant material was collected in the Gran Paradiso National Park, Aosta Valley, Italy, and the rhizome and leaves were micromorphologically and phytochemically characterized. Polyphenol-enriched hydroalcoholic rhizome and leaf extracts, used in cell-free assays, showed strong and concentration-dependent antioxidant and anti-inflammatory activities. In vitro tests revealed cyclooxygenase and lipoxygenase inhibition by the leaf extract, while the rhizome extract induced only lipoxygenase inhibition. MTT assays on HaCaT keratinocytes and L929 fibroblasts showed low cytotoxicity of extracts. In vitro scratch wound test on HaCaT resulted in a strong induction of wound closure with the leaf extract, while the effect of the rhizome extract was lower. The same test on L929 cells showed similar wound closure induction with both extracts. The results confirmed the traditional medicinal uses of the rhizome as an anti-inflammatory and wound healing remedy for superficial injuries but also highlighted that the leaves can be exploited for these purposes with equal or superior effectiveness.