RESUMEN

Stachys scardica Griseb. is a Balkan endemic species listed in The Red Data Book of Bulgaria with the conservation status "endangered". Successful micropropagation was achieved on MS medium supplemented with 1.5 mg/L benzyladenine (BA), followed by a subsequent ex vitro adaptation in an experimental field resulting in 92% regenerated plants. Using nuclear magnetic resonance (NMR), phenylethanoid glycosides (verbascoside, leucosceptoside A), phenolic acids (chlorogenic acid), iridoids (allobetonicoside and 8-OAc-harpagide), and alkaloids (trigonelline) were identified, characteristic of plants belonging to the genus Stachys. High antioxidant and radical scavenging activities were observed in both in situ and ex vitro acclimated S. scardica plants, correlating with the reported high concentrations of total phenols and flavonoids in these variants. Ex vitro adapted plants also exhibited a well-defined anti-inflammatory potential, demonstrating high inhibitory activity against the complement system. Employing a disk diffusion method, a 100% inhibition effect was achieved compared to positive antibiotic controls against Staphylococcus epidermidis and Propionibacterium acnes, with moderate activity against Bacillus cereus. The induced in vitro and ex vitro model systems can enable the conservation of S. scardica in nature and offer future opportunities for the targeted biosynthesis of valuable secondary metabolites, with potential applications in the pharmaceutical and cosmetic industries.

RESUMEN

The present work aims to assess the biological potential of polyphenolic compounds in different parts (flowers, leaves, stems, and roots) of Stachys palustris L. Towards secondary metabolites profile, 89 polyphenolic compounds (PCs) were identified by UPLC-PDA-ESI-TQD-MS/MS, with a total average content of 6089 mg/100 g of dry matter (d.m.). In terms of biological activity, antioxidant activity (radical activity, reducing power), digestive enzyme inhibitory (α-glucosidase, α-amylase, pancreatic lipase) effect, and antiproliferative activity (inhibition of cell viability and induction of apoptosis in different human cancer cell lines) were explored. Leaves, flowers, stems, and roots of S. palustris L. have not been studied in this regard until now. Vescalagin and cocciferin d2, isoverbascoside (verbascoside), luteolin 6-C-glucoside, luteolin 6-C-galactoside, apigenin 6-C-glucoside, (-)-epicatechin, ellagic acid, and malvidin 3-O-diglucoside were detected as main ingredients in the studied parts. Methanolic extract of S. palustris L. leaves and flowers revealed the highest amount of PCs with the strongest antiradical (18.5 and 15.6 mmol Trolox equivalent (TE)/g d.m., respectively) and reducing power effects (7.3 and 5.6 mmol TE/g d.m.). Leaf extracts exhibited better α-amylase and pancreatic lipase inhibition effects, while flower extracts exhibited better α-glucosidase inhibition effect. Regarding antiproliferative activity, extracts of the leaves and flowers significantly reduced cell viability and induced a high level of apoptosis in human lung, pancreatic, bladder, and colon cancer cell lines, as well as in human acute myeloid leukemia; whereas the extracts from stems and roots revealed the weaker effects. The results of this work showed anti-proliferative and potentially anti-diabetic, anti-obesity properties of S. palustris L., especially for flowers and leaves, which may have wide potential applications in the functional food, special food, pharmaceutical, cosmetics industries, and/or in medicine.

RESUMEN

Stachys thracica Davidov is a Balkan endemic species distributed in Bulgaria, Greece, and Turkey. In Bulgaria, it is classified as "rare" and is under the protection of the Bulgarian biodiversity law. The aim of our study was to develop an efficient protocol for ex situ conservation of S. thracica and to perform comparative NMR-based metabolite profiling and bioactivity assays of extracts from in situ grown, in vitro cultivated, and ex vitro acclimated plants. Micropropagation of S. thracica was achieved by in vitro cultivation of mono-nodal segments on basal MS medium. Ex vitro adaptation was accomplished in the experimental field with 83% survival while conserved genetic identity between in vitro and ex vitro plants as shown by the overall sequence-related amplified polymorphism marker patterns was established. Verbascoside, chlorogenic acid, and trigonelline appeared the main secondary metabolites in in situ, in vitro cultivated, and ex vitro acclimated S. thracica. High total phenolic and flavonoid content as well as antioxidant and radical scavenging activity were observed in in situ and ex vitro plants. Further, the anti-inflammatory activity of S. thracica was tested by hemolytic assay and a high inhibition of the complement system was observed. Initiated in vitro and ex vitro cultures offer an effective tool for the management and better exploitation of the Stachys secondary metabolism and the selection of lines with high content of bioactive molecules and nutraceuticals.

RESUMEN

The composition of essential oils from Stachys byzantina was studied by simple method based on gas chromatography-mass spectrophotometry (GC-MS) following microwave assisted headspace single-drop microextraction (MA-HS-SDME) method. Several parameters affecting MA-HS-SDME such as sample mass, solvent volume, extraction time, microwave power and the nature of extracting solvent were optimised. The MA-HS-SDME method was compared with traditional hydrodistillation (HD) method. Within the study elaborated, thirty-eight components were extracted and identified. Compared with HD, MA-HS-SDME is an easy, rapid and efficient method for the analysis of essential oils in S. byzantina.

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RESUMEN

Total phenolic and flavonoid contents and antioxidant activity of four Iranian herbs (Lamiaceae) were investigated. The antioxidant activity of methanol extracts of thyme (Thymus daenensis Celak.), Bakhtiari savory (Satureja bachtiarica Bung.), dragonhead (Dracocephalum multicaule Montbr & Auch), and woundwort (Stachys lavandulifolia Vahl.) was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing/antioxidant power (FRAP), and trolox equivalent antioxidant capacity (TEAC). A comparison of all plant extracts in the DPPH assay indicated that dragonhead and thyme were the most effective free radical scavenging agents. Thyme demonstrated a relatively strong antioxidant activity in both the FRAP and TEAC assays. The total phenolic content of all the extracts ranged from 99 to 208 mg TAE/g extract with thyme exhibiting the highest phenolic content. The flavonoid content of the extracts, which ranged from 10.1 to 22.2 rutin equivalents/g of extract, was highest in dragonhead. A positive correlation was noted between the total phenolic content and antioxidant activity in both the FRAP and TEAC assays, while no significant correlation was observed between the DPPH, TEAC, and FRAP assay and total flavonoid, suggesting that the level of antioxidant activity in these plants varies greatly, but the total phenolic in the plant extracts provided a substantial antioxidant activity. Experimental results indicate that thyme and dragonhead extracts could be an important dietary source of phenolic compounds with high antioxidant capacity.

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