Distribution and levels of phytoecdysteroids in plants of the genus Silene during development

Investigation of the inhibitory activity of extracts, fractions and secondary metabolites of <i>Silene</i> spp. (<i>Caryophyllaceae</i>) and <i>Serratula cupuliformis</i> (<i>Asteraceae</i>) on the replication of SARS-CoV-2 coronavirus

Aim. In vitro analysis of the inhibitory activity of extracts, fractions and secondary metabolites of plants of the genus Silene [Caryophylaceae] and Serratula cupuliformis [Asteraceae) on the replication of SARS-CoV-2.

Material and Methods. Silene spp. and Serratula cupuliformis of the Siberian Botanical Garden of National Research Tomsk State University were used. Ethanol extracts and butanol fractions of Silene spp. were prepared. The flavonoid shaftoside and the ecdysteroid 20-hydroxyecdysone from Lychnis chalcedonica were isolated. Analysis of BAS was carried out by the HPLC method. In vitro analysis of the inhibitory activity of extracts on SARS-CoV-2 replication was performed in Vero cell culture by direct inactivation [neutralization) of virions. Comparison samples were dry ethanol extracts of chaga [Inonotus obliquus, Basidiomycota), spices of cloves [Syzygium aromaticum, Myrtaceae) and root of licorice [Glycyrrhiza glabra L., Fabaceae).

Results. The inhibitory activity of ethanol extracts and butanol fractions of Silene spp., as well as individual compounds [shaftozide and 20-E) was revealed in the range of 50% effective concentrations [EC50) when dissolved in water from 339.85±83.92 pg/ml to 1.59±0.39 pg/ml and when dissolved in DMSO from 119.34±26.34 pg/ml to 2.22±0.57 pg/ml, respectively. The butanol fraction of Serratula cupuliformis was active with EC50=21.74±4.80 and 27.42±6.05 pg/mL. These results for some samples of Silene spp. and Serratula cupuliformis are comparable to the EC50 values of the comparators.

Conclusion. The results obtained suggest the presence of biologically active substances in the herbal preparations studied that act destructively on virions of SARS-CoV-2 and affect one of the main stages of its "life" cycle - on the attachment to receptors of sensitive cells.

Phytoecdysteroids: Distribution, Structural Diversity, Biosynthesis, Activity, and Crosstalk with Phytohormones

Phytoecdysteroids (PEs) are naturally occurring polyhydroxylated compounds with a structure similar to that of insect molting hormone and the plant hormone brassinosteroids. PEs have a four-ringed skeleton composed of 27, 28, 29, or 30 carbon atoms (derived from plant sterols). The carbon skeleton of ecdysteroid is known as cyclopentanoperhydrophenanthrene and has a β-sidechain on C-17. Plants produce PEs via the mevalonate pathway with the help of the precursor acetyl-CoA. PEs are found in algae, fungi, ferns, gymnosperms, and angiosperms; more than 500 different PEs are found in over 100 terrestrial plants. 20-hydroxyecdysone is the most common PE. PEs exhibit versatile biological roles in plants, invertebrates, and mammals. These compounds contribute to mitigating biotic and abiotic stresses. In plants, PEs play a potent role in enhancing tolerance against insects and nematodes via their allelochemical activity, which increases plant biological and metabolic responses. PEs promote enzymatic and non-enzymatic antioxidant defense systems, which decrease reactive oxygen species in the form of superoxide radicals and hydroxyl radicals and reduce malondialdehyde content. PEs also induce protein biosynthesis and modulate carbohydrate and lipid synthesis. In humans, PEs display biological, pharmacological, and medicinal properties, such as anti-diabetic, antioxidant, anti-microbial, hepatoprotective, hypoglycemic, anti-cancer, anti-inflammatory, antidepressant, and tissue differentiation activity.

Rapid Characterization of Components in Bolbostemma paniculatum by UPLC/LTQ-Orbitrap MSn Analysis and Multivariate Statistical Analysis for Herb Discrimination

Bolbostemma paniculatum is a traditional Chinese medicine (TCM) showed various therapeutic effects. Owing to its complex chemical composition, few investigations have acquired a comprehensive cognition for the chemical profiles of this herb and explicated the differences between samples collected from different places. In this study, a strategy based on UPLC tandem LTQ-Orbitrap MSⁿ was established for characterizing chemical components of B. paniculatum. Through a systematic identification strategy, a total of 60 components in B. paniculatum were rapidly separated in 30 min and identified. Then based on peak intensities of all the characterized components, principle component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to classify 18 batches of B. paniculatum into four groups, which were highly consistent with the four climate types of their original places. And five compounds were finally screened out as chemical markers to discriminate the internal quality of B. paniculatum. As the first study to systematically characterize the chemical components of B. paniculatum by UPLC-MSⁿ, the above results could offer essential data for its pharmacological research. And the current strategy could provide useful reference for future investigations on discovery of important chemical constituents in TCM, as well as establishment of quality control and evaluation method.

Plant ecdysteroids: plant sterols with intriguing distributions, biological effects and relations to plant hormones

The present review summarises current knowledge of phytoecdysteroids' biosynthesis, distribution within plants, biological importance and relations to plant hormones. Plant ecdysteroids (phytoecdysteroids) are natural polyhydroxylated compounds that have a four-ringed skeleton, usually composed of either 27 carbon atoms or 28-29 carbon atoms (biosynthetically derived from cholesterol or other plant sterols, respectively). Their physiological roles in plants have not yet been confirmed and their occurrence is not universal. Nevertheless, they are present at high concentrations in various plant species, including commonly consumed vegetables, and have a broad spectrum of pharmacological and medicinal properties in mammals, including hepatoprotective and hypoglycaemic effects, and anabolic effects on skeletal muscle, without androgenic side-effects. Furthermore, phytoecdysteroids can enhance stress resistance by promoting vitality and enhancing physical performance; thus, they are considered adaptogens. This review summarises current knowledge of phytoecdysteroids' biosynthesis, distribution within plants, biological importance and relations to plant hormones.

Phytoecdysteroids of the East Asian Caryophyllaceae

BACKGROUND

Occurrence of integristerone A (1), 20-hydroxyecdysone (2), ecdysone (3), 2-deoxy-20-hydroxyecdysone (4) has been analyzed in 64 species of the East Asian Caryophyllaceae.

MATERIALS AND METHODS

Ecdysteroid content was determinate by high-performance liquid chromatography (HPLC). HPLC with a high-resolution mass spectrometry was performed on Shimadzu LCMS-IT-TOF (Japan) system equipped with a LC-20A Prominence liquid chromatograph, a photodiode array detector SPD-M20A and ion-trap/time-of-flight mass spectrometer.

RESULTS

New sources of phytoecdysteroids: Melandrium sachalinense and Melandrium firmum have been revealed. It is the 1(st) time that two has been identified in M. sachalinense and M. firmum; 1 in the species: Lychnis fulgens, Silene repens, Silene foliosa, Silene stenophylla, Silene jenisseensis and M. sachalinense; 3 in Lychnis cognata; 4 in L. fulgens, S. stenophylla and S. jenisseensis (the tribe Lychnideae, the subfamily Caryophylloideae). Ecdysteroid-negative taxa are Spergularia rubra of the tribe Sperguleae; species of the genera Minuartia, Honckenya, Eremogone, Arenaria, Moehringia, Pseudostellaria, Fimbripetalum, Stellaria and Cerastium of the tribe Alsineae; Scleranthus annuus of the tribe Sclerantheae, as well as the East Asian representatives of the genera Gypsophila, Psammophiliela, Dianthus and Saponaria of the tribe Diantheae; Oberna and Agrostemma of the tribe Lychnideae.

CONCLUSION

This investigation shows the most promising sources of ecdysteriods are species of genera Silene and Lychnis.

Antiulcer activity of extracts of ecdysteroid-containing plants of genera Lychnis and Silene of the Caryophyllaceae family

We studied antiulcer activity of the extracts of ecdysteroid-containing plants of the Caryophyllaceae family: Lychnis chalcedonica L., Silene viridiflora L.Sp.Pl., and Silene frivaldszkyana Hampe. Experiments on the model of neurogenic and aspirin-induced ulcerogenesis showed unidirectional and pronounced gastroprotective effects of S. viridiflora and L. chalcedonica extracts comparable to the efficacy of famotidine. In these models, a course of intragastric treatment with the extracts reduced ulcerative lesions of all types.

Diversity of Secondary Metabolites in the Genus Silene L. (Caryophyllaceae)—Structures, Distribution, and Biological Properties

The genus Silene (family Caryophyllaceae) comprises more than 700 species, which are widely distributed in temperate zones of the Northern Hemisphere, but are also present in Africa and have been introduced in other continents. Silene produces a high diversity of secondary metabolites and many of them show interesting biological and pharmacological activities. More than 450 compounds have been isolated; important classes include phytoecdysteroids (which mimic insect molting hormones), triterpene saponins (with detergent properties), volatiles, other terpenoids and phenolics. This review focusses on the phytochemical diversity, distribution of Silene secondary metabolites and their biological activities.

Into the world of steroids: a biochemical "keep in touch" in plants and animals

Evolution of steroids such as sex hormones and ecdysteroids occurred independently in animal and plant kingdoms. Plants use phytoecdysteroids (PEs) to control defence interactions with some predators; furthermore, PEs can exert beneficial influence on many aspects of mammalian metabolism. Endocrine disrupting compounds such as the estrogen agonist bisphenol A (BPA) are widespread in the environment, posing a potential hormonal risk to animals and plants. Adverse BPA effects on reproductive development and function are coupled with other toxic effects. BPA bioremediation techniques could be developed by exploiting some tolerant plant species.

The phytoecdysteroid profiles of 7 species of Silene (Caryophyllaceae)

The phytoecdysteroid profiles of extracts of aerial parts of flowering plants of 7 ecdysteroid-containing species in the genus Silene (Caryophyllaceae; S. fridvaldszkyana Hampe, S. gigantea L., S. graminifolia Otth, S. mellifera Boiss. & Reuter, S. repens Patr., S. schmuckeri Wettst., and S. sendtneri Boiss.) have been examined and identified by HPLC and, in the case of two new compounds, by mass spectrometry and NMR. S. frivaldszkyana was found to contain predominantly 20-hydroxyecdysone (20E), with smaller amounts of 2-deoxyecdysone (2dE), 2-deoxy-20-hydroxyecdysone (2d20E), polypodine B (polB), integristerone A (IntA), 26-hydroxypolypodine B (26polB), and 20,26-dihydroxyecdysone (20,26E). Additionally, a new minor ecdysteroid, 26-hydroxyintegristerone A, has been identified from this species. S. gigantea contains 3 major ecdysteroids (2dE, 2d20E, and 20E) and much smaller amounts of intA and 2-deoxy-20-hydroxyecdysone 25-beta-D-glucoside, which is a new ecdysteroid. Ecdysteroids in the other 5 species have been identified by co-chromatography with reference compounds on RP- and NP-HPLC systems. There is considerable variability with regard to ecdysteroid profiles within the genus Silene. The chemotaxonomic value of ecdysteroid profiles within the genus Silene is discussed.

New Minor Ecdysteroids from Silene viridiflora

Two new minor ecdysteroids, the 2,22- and 3,22-diacetates of 20,26-dihydroxyecdysone have been isolated from the aerial part of Silene viridiflora L. (Caryophyllaceae).

Distribution of phytoecdysteroids in the Caryophyllaceae

Certain genera within the Caryophyllaceae (especially Silene and Lychnis) have received a significant amount of attention with regard to the isolation and identification of ecdysteroids. However, the taxonomy of this family is difficult. Hence, the occurrence of phytoecdysteroids in members of the Caryophyllaceae is presented, and combined with new data on ecdysteroid agonist (phytoecdysteroid) and antagonist activities, in order to survey the distribution of phytoecdysteroid-containing species within this large family, and to assess the utility of phytoecdysteroids as chemotaxonomic markers. The new data presented (representing ca. 110 species) have been obtained by the application of sensitive biological/biochemical methods for the detection of ecdysteroid agonists and antagonists, using Drosophila melanogaster B(II) bioassay and ecdysteroid-specific immunoassays. In the antagonist version of the B(II) bioassay, only weak ecdysteroid antagonist activities were detected in a few of the extracts. From both new and previously available data, it was found that phytoecdysteroids were present predominantly in the Genera Lychnis, Petrocoptis, Sagina and Silene. Comparison of ecdysteroid occurrence with a molecular phylogeny for the tribe Sileneae [Taxon 44 (1995) 525] revealed close association of ecdysteroid occurrence with certain groups of this tribe. In 14 species of Silene examined, there is a reasonable, but not absolute, relationship between the presence of ecdysteroids in the seeds and in other plant parts. Where ecdysteroids are present in the plant, highest concentrations are generally present in the roots.

5-Alpha- and 5-beta-2-deoxyintegristerone A, a 5-alpha and 5-beta isomer pair of ecdysteroids isolated from the Silene genus

5-Alpha-2-deoxyintegristerone A and 5-beta-2-deoxyintegristerone A were isolated from the aerial parts of Silene italica ssp. nemoralis (Waldst. and Kit.) Nyman using a specific combination of absorption column chromatography, preparative thin-layer chromatography and preparative HPLC. Both normal-phase and reversed-phase modes of HPLC were employed for isolation. Structural elucidation of 5-alpha-2-deoxyintegristerone A was completed by X-ray diffraction. Both 5-alpha-2-deoxyintegristerone A and 5-beta-2-deoxyintegristerone A were firstly isolated from this plant. We propose that 5-alpha-2-deoxyintegristerone A is not an artifact but an integral part of the ecdysteroid spectrum of Silene italica ssp. nemoralis (Waldst. and Kit.) Nyman.

Identification and quantitative analysis of the phytoecdysteroids in Silene species (Caryophyllaceae) by high-performance liquid chromatography. Novel ecdysteroids from S. pseudotites

Many species in the genus Silene (Caryophyllaceae) have previously been shown to contain ecdysteroids and this genus is recognised as a good source of novel ecdysteroid analogues. We have used ecdysteroid-specific radioimmunoassays and the microplate-based Drosophila melanogaster B(II) cell bioassay for ecdysteroid agonist and antagonist activities to identify further phytoecdysteroid-containing species in this genus. The main ecdysteroid components from 10 Silene species (S. antirrhina, S. chlorifolia, S. cretica, S. disticha, S. echinata, S. italica, S. portensis, S. pseudotites, S. radicosa, S. regia) were isolated and identified, mainly by normal-phase and reversed-phase high-performance liquid chromatography. The amount of each ecdysteroid was determined by comparing chromatogram peak areas with those for reference 20-hydroxyecdysone (20E) on reversed-phase HPLC. 20E is the most abundant ecdysteroid in each of the Silene extracts. Polypodine B, 2-deoxy-20-hydroxyecdysone and ecdysone are also common ecdysteroids in these Silene species, but the proportions of these ecdysteroids vary between the Silene species. HPLC proved to be a quick and effective way to screen Silene species, determine ecdysteroid profiles and, hence, identify extracts containing novel analogues. An extract of the aerial parts of S. pseudotites was found to contain several new ecdysteroids. These have been isolated and identified spectroscopically (by NMR and mass spectrometry) as 2-deoxyecdysone 22beta-D-glucoside, 2-deoxy-20,26-dihydroxyecdysone and 2-deoxypolypodine B 3beta-D-glucoside. Additionally, (5alpha-H)-2-deoxyintegristerone A (5alpha-2H 91%, 5alpha-1H 9%) was isolated as an artefact. This study contributes to the understanding of ecdysteroid distribution in Silene species and provides further information on the chemotaxonomic significance of ecdysteroids in Silene species.

Phytoecdysteroids in seeds of Lloydia serotina (Liliaceae)

Seeds of a number of species in the Liliaceae (sensu Brummitt, 1992) were examined for the presence of ecdysteroid agonist and antagonist activities. No species were antagonistic to 20-hydroxyecdysone action on the ecdysteroid-responsive Drosophila melanogaster B(II) cell line and only one extract, that of Lloydia serotina, was agonistic. This activity is attributable to the presence of phytoecdysteroids as detected by ecdysteroid-specific radioimmunoassay and the agonist version of the B(II) bioassay. HPLC in conjunction with radioimmunoassay and bioassay have been used to determine the ecdysteroid profile. The major ecdysteroids present are identified as 20-hydroxyecdysone and polypodine B (5beta,20-dihydroxyecdysone).

Phytoecdysteroids: biological aspects

Phytoecdysteroids are a family of about 200 plant steroids related in structure to the invertebrate steroid hormone 20-hydroxyecdysone. Typically, they are C27, C28 or C29 compounds possessing a 14alpha-hydroxy-7-en-6-one chromophore and A/B-cis ring fusion (5beta-H). In the present review, the distribution, biosynthesis, biological significance and potential applications of phytoecdysteroids are summarised.