Plant Growth Regulators and Activated Charcoal Selectively Affect Phenylethanoid and Flavone Glycoside Accumulation in Sideritis scardica Griseb. Tissue Culture.

Sideritis scardica Griseb. is a Balkan endemic species traditionally used for the treatment of pulmonary emphysema and angina pectoris. Recent research has also shown its phytotherapeutic potential as an anticancer and neuroprotective agent. These findings, as well as the endangered status of the species in its wild habitats, have motivated the present research on application of plant cell tissue and organ culture for the purposes of both valuable germplasm conservation and secondary metabolites production. Shoot cultures of the plant were initiated from sterile germinated seeds and the effects of activated charcoal (AC), as well benzyl adenine and 1-naphthaleneacetic acid treatments, were experimented. The phenolic profile analysis was performed by HPLC/DAD/MSn. Comparison with samples collected from wild plants in their natural habitat was performed. It was established that in vitro multiplication induced by plant growth regulators (PGRs) was accompanied by a higher impairment of leaf morphology and trichome formation, as well as by the occurrence of plantlet hyperhydricity and callus formation, as compared with the AC treatments. Shoot culture-derived plant material was shown to produce two phenylethanoids and five flavone glycosides, not detected in the wild collected plant material. In addition, the two types of in vitro culture treatments led to the stimulation of either flavone glycosides or phenylethanoids in the in vitro cultivated plants. Thus, AC stimulated, to a higher extent, flavone glycosides' accumulation, leading to an elevated flavone/phenylethanoid ratio, as compared with PGR treatments.

Genus Sideritis, section Empedoclia in southeastern Europe and Turkey - studies in ethnopharmacology and recent progress of biological activities.

BACKGROUND: Over the last two decades there has been a substantial increase of the number of studies on the species of genus Sideritis. Species of section Empedoclia, occurring in the Eastern Mediterranean region and in part of Western Asia possess some remarkable characteristics and are known as valuable medicinal plants used by local people in the traditional medicine and for herbal tea. The objective of the review is to make a survey on the recent studies on the ethnopharmacology and biological activity of the species in Southeastern Europe and in Turkey, which is the center of distribution and their main occurrence. MAIN BODY: The review focuses on the ethnopharmacology and biological activities of the species of interest. The survey revealed that a total of 47 species belonging to section Empedoclia have been studied either in ethnopharmacological aspect, or in relation to their biological activities, or both. Most species have been used traditionally by the local people as herbal tea or for treatment of various health problems, most frequently flu, cold and respiratory diseases. Sideritis species demonstrate numerous biological activities and are promising for use in the therapy of many diseases and health disorders. Antioxidant activity was found in 40 species, antimicrobial and antibacterial activity - in 27 species, anti-inflammatory - in 14 species, antifungal - in 8 species, cytotoxic - in 7 species. There were also some other, more specific biological activities, found in a few species, but considered promising for further studies and application. SHORT CONCLUSION: The species of genus Sideritis, section Empedoclia have been used by local people as herbal tea and in traditional medicine since long time ago. People are taking advantage of the high species diversity and are aware of their useful properties. Much more information is available on the biological activities of the target species than on their traditional uses. Most species demonstrate various biological activities and are of substantial interest for further studies on their pharmacological properties and their potential for pharmacy and medicine. Graphical abstract Schematic illustration of traditional uses and biological activities of some Sideritis species. Arrows with different colors represent biological activities of different species. The species and their corresponding color can be seen at the right part of the figure. The colors correspond also to the squares placed in the different parts of human body.

Phenolic Profile of Artemisia alba Turra.

The aim of this study was to evaluate flower and leaf methanol extracts of Artemisia alba Turra for their total phenolic and flavonoid contents, antioxidant capacity and to investigate their phenolic composition. The flower extract was richer in total phenolics and flavonoids and possessed higher antioxidant activity through DPPH and ABTS assays. The UHPLC-PDA-MS analysis of the flower and leaf methanol extracts revealed similar phenolic profile and allowed identification of 31 phenolic compounds (flavonoids, coumarins, and phenolic acids) by comparison with the respective reference compounds or tentatively characterized by their chromatographic behavior, UV patterns, and MS fragmentations. The presence of hispidulin, jaceosidin, desmethoxycentaureidin, and dicaffeoyl esters of quinic acid in A. alba is reported herein for the first time. The distribution of flavonoids in A. alba from different origins was discussed from chemotaxonomic point of view.

Essential oil composition of Inula britannica L. from Bulgaria.

The separately distilled flowers (F) and leaves' (L) essential oils of Inula britannica L. were investigated using capillary gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 83 constituents, representing 96.91% (F) and 96.73% (L) of the total oils, were registered. The oils were rich in terpenoids (57.85% and 77.28%), of which sesquiterpenoids dominated. The main constituents of the essential oils were viridiflorol (7.17%-8.20%) and himachalol (3.45%-8.71%) followed by 6,10,14-trimethyl-2-pentadecanone (5.43%-2.95%), 13-tetradecanolide (3.93%-4.87%) and 3-methyl-4-propyl-2,5-furandione (4.06%-0.29%).

Phytochemical Profile of Inula britannica from Bulgaria.

The flower heads of Inula britannica L. of Bulgarian origin afforded sesquiterpene lactones (gaillardin, britannin, I1, 13-dihydroinuchinenolide B, ivalin, pulchellin C), triterpenoids (3-0-palmitates of 160-hydroxylupeol, 16ß-hydroxy-ß-amyrin, and faradiol) and flavonoids (quercetin, luteolin, luteolin-7-0- glucoside). All compounds are known and they were identified by spectral methods. The observed differences in the chemical content of the chloroform and methanol extracts were also reflected in their free radical scavenging activity, evaluated by DPPH and ABTS assays. Intraspecific variability of L britannica is discussed.

Highly oxygenated sesquiterpenes in Artemisia alba Turra.

Ten new sesquiterpene alcohols of which seven germacranes, a eudesmane, a guaiane and an oplopane were isolated from the aerial parts of Artemisia alba Turra. Their structures and relative stereochemistry were elucidated by spectral methods ((1)H and (13)C NMR, COSY, HSQC, HMBC, NOESY, and MS). In addition, the known 7-hydroxycadin-4-en-3-one, centaureidin and axillarin were found for the first time in the studied species.

Cytokinin and auxin effect on the terpenoid profile of the essential oil and morphological characteristics of shoot cultures of Artemisia alba.

The influence of plant growth regulators (PGR) on the essential oil composition and in vitro development of A. alba shoot cultures was studied. Two types of oils were determined, based on their terpenoid content. Close relations between the morphogenetic effects of PGR and the essential oil profile of the species were observed Predominance of root over shoot development was connected with a drop in the amounts of sesquiterpenoids and the direction of biosynthesis towards oxygenated monoterpenoids in the PGR-free control medium, as well in those with 1.0 mg L(-1) indole-3-butyric acid (IBA) supplementation. On the contrary, lack of root formation and stimulated callusogenesis caused by the addition of 0.2 mg L(-1) 6-benzyladenine (BA), irrespectively of the presence of IBA (either 0.5 mg L(-1) or 1.0 mg L(-1)), resulted in the strong prevalence of sesquiterpenoids in the oils. These results are indicative that the morphological development ofA. alba shoot cultures affects the terpenoid biosynthetic pathway bringing out the hypothesis for a possible root to shoot signaling.