A protocol for in vitro production of genetically uniform populations of the medicinal plant Eryngium planum, rich in selected phenolic acids, has been established. Shoot-tips were collected from axenic seedlings and grown on a Murashige and Skoog basal medium supplemented with 6-Benzyladenine (BA) and Indole-3-acetic acid (IAA). The highest shoot proliferation efficiency (17 shoots per explant) was obtained when 1.0 mg L -1 BA and 0.1 mg L -1 were added. Proliferating shoots were rooted and transferred to soil (89 % frequency of survival). Flow cytometric analysis of intact (field-grown) and microrpropagated plants revealed that all plants were uniform in genome size and had similar DNA contents. Thin-layer chromatography (TLC) analysis indicated that multiple shoots and roots from in vitro-derived plants produced high amounts of phenolic acids, primarily of rosmarinic acid (RA). Levels of phenolic acids in in vitroderived plants were similar to those of intact plants. Furthermore, high-performance liquid chromatography revealed that root cultures in liquid medium accumulated substantial levels of RA. Thus, rapid establishment of in vitro-grown organ cultures of E. planum can also serve as reliable sources for bioactive compounds.

Eryngium planum L. cell and organ cultures were maintained on Murashige and Skoog media (MS), supplemented with exogenous hormones of different types and various concentrations for high biomass growth. The callus and cell suspension cultures were treated with increased sucrose concentration and/or elicited by methyl jasmonate for the enhancement of selected phenolic acids accumulation. Three phenolic acids, rosmarinic acid (RA), chlorogenic acid (CGA) and caffeic acid (CA), were detected by HPLC-DAD in those cultures. The sum of their content in the dry material was found to be higher in the shoot culture (3.95 mg g -1 ), root culture (7.05 mg g -1 ), callus (6.20 mg g -1 ) and cell suspension (2.04 mg g -1 ) than in the leaves (1.87 mg g -1 ) and roots (0.76 mg g -1 ) of intact plants. The major compound of in vitro cultures was always rosmarinic acid. The content of RA could be increased approximately threefold (16.24 mg g -1 ) in the callus culture and approximately twofold (3.91 mg g -1 ) in the cell suspension culture by elicitation with 100 lM methyl jasmonate (MeJA). The higher concentration of sucrose (S) in the medium (5, 6 %) led to over a twofold increase of CGA content in the callus culture (2.54 mg g -1 ).The three mentioned phenolic acids have been found in E. planum undifferentiated and differentiated in vitro cultures for the first time.

Ecdysteroids are secondary metabolites, widely distributed in the animal and plant kingdoms. They have a wide range of pharmacological effects in vertebrates, including mammals, most of which are beneficial for humans. Therefore, they have become compounds of interest for the pharmaceutical industry due to their adaptogenic, anabolic, hypoglycaemic, hypocholesterolaemic and antimicrobial activities, which are still being researched. Nowadays, ecdysteroids are present as active ingredients in bodybuilding supplements. Because of their complex structures, their chemical synthesis seems unprofitable and impractical. Due to high content of ecdysteroids in many plants, they are primarily obtained by extraction of the plant material. Plant in vitro cultures provide an alternative source of these compounds, helping to avoid problems associated with field production—such as variable yield or dependence on environmental factors, as well as limited availability of natural resources. Plant cell and tissue cultures may be suggested as alternatives for the production of plant biomass rich in pharmaceutically active ecdysteroids. Moreover, the use of common biotechnological strategies, such as elicitation or precursor feeding, may further increase the yield and improve production of these compounds. In this paper, we describe general information about ecdysteroids: their structure, biosynthesis, distribution, role in plants, and we review recent studies on micropropagation of ecdysteroid-producing plants and cell cultures, and potential ability of ecdysteroids enhancement in in vitro cultures.

Eryngium maritimum L. is a valuable medicinal species, but since it is protected plant, collection from natural populations is forbidden. Therefore, establishing an efficient system for micropropagation of this species is desirable. To determine the optimal nutritional factors needed for shoot multiplication, root development and secondary metabolites accumulation, different media and plant growth regulators were tested. The highest plant regeneration efficiency (over 96 %), with 4.4 shoots per explant was induced on Murashige and Skoog (MS) medium supplemented with 1.0 mg L -1 benzyladenine (BA) and 0.1 mg L -1 indole-3-acetic acid (IAA). The in vitroregenerated shoots were rooted (83.3-100 %) and transferred to an experimental plot with 62 % efficiency. Flow cytometric analysis revealed no variation in nuclear DNA content in field-and in vitro-delivered plant material. Ultra high performance liquid chromatography (UHPLC) indicated that multiple shoots and roots from in vitroregenerated plantlets and adventitious root cultures maintained the production of rosmarinic (RA) and chlorogenic (CGA) acids and triterpenoid saponins found in the rosette leaves and roots of E. maritimum intact plants. UHPLC revealed a 12-fold increase of RA and CGA and 3.2-fold higher accumulation of triterpenoid saponins in roots of in vitro-derived plantlets in comparison to roots from fieldgrown plants. Adventitious root cultures allowed continuous growth of excised root in liquid media with or without exogenous auxins. The roots grown in liquid medium supplemented with 0.1 mg L -1 IAA showed higher (227-fold) phenolic acids accumulation than those without auxin. Obtained results confirmed that micropropagation is a useful strategy in the protection of endangered species and a renewable source of a high quality plant material for secondary metabolites production.

In vitro cultures give the opportunity to perform the phytochemical studies on the protected species without harvesting the plant material from the natural environment. Shoots of Eryngium alpinum L. were multiplied on Murashige and Skoog (MS) medium in various systems, namely on the solid media and in two liquid cultures-stationary and agitated, as well as via regeneration from callus. The biomass increments were closely correlated with the number of shoots arising from one explant, which was connected with the supplementation of the culture media with the studied plant growth regulators. The methanolic extracts from shoots grown in the tested systems were subjected to phenolic acids and flavonoids qualitative and quantitative analysis. Biomass from in vitro shoot cultures accumulated from 19.59 to 32.95 times more phenolic acids [the total content ranged from 272.52 to 458.38 mg/100 g dry weight (DW)] and from 3.02 to 4.43 times more flavonoids (the total content ranged from 100.03 to 146.98 mg/100 g DW), depending on the culture system, than the extracts from basal leaves from the intact plant (13.91 and 33.16 mg/100 g DW, respectively). The phenolics present in shoot cultures include seven phenolic acids-3,4-dihydroxyphenylacetic, caftaric, caffeic, neochlorogenic, chlorogenic, isochlorogenic, and rosmarinic acids, and three flavonoids-isoquercetin, quercitrin and robinin. The best system for shoot proliferation resulting in the highest biomass growth and phenolic acids and flavonoids accumulation was solid culture on MS medium with BAP, IAA, and GA 3 (each 1.0 mg/l). The aim of this work was to check the effect of various culture systems (stationary and agitated, on solidified and in liquid media) on the production of phenolic compounds in E. alpinum shoots cultured in vitro. Key messageThis is the first report on phenolic acids and flavonoids estimation in Eryngium alpinum in vitro biomass from different culture systems.Keywords Alpine eryngo · Shoot multiplication · Phenolic acids · Flavonoids · HPLC-DAD analysis 1995). Some of the individuals are threatened by humansthe plant is collected for ornamental and commercial use and