Mitigation of salinity stress in yarrow (Achillea millefolium L.) plants through spermidine application.

This study investigated the mitigating effects of spermidine on salinity-stressed yarrow plants (Achillea millefolium L.), an economically important medicinal crop. Plants were treated with four salinity levels (0, 30, 60, 90 mM NaCl) and three spermidine concentrations (0, 1.5, 3 µM). Salinity induced electrolyte leakage in a dose-dependent manner, increasing from 22% at 30 mM to 56% at 90 mM NaCl without spermidine. However, 1.5 µM spermidine significantly reduced leakage across salinities by 1.35-11.2% relative to untreated stressed plants. Photosynthetic pigments (chlorophyll a, b, carotenoids) also exhibited salinity- and spermidine-modulated responses. While salinity decreased chlorophyll a, both spermidine concentrations increased chlorophyll b and carotenoids under most saline conditions. Salinity and spermidine synergistically elevated osmoprotectants proline and total carbohydrates, with 3 µM spermidine augmenting proline and carbohydrates up to 14.4% and 13.1% at 90 mM NaCl, respectively. Antioxidant enzymes CAT, POD and APX displayed complex regulation influenced by treatment factors. Moreover, salinity stress and spermidine also influenced the expression of linalool and pinene synthetase genes, with the highest expression levels observed under 90 mM salt stress and the application of 3 µM spermidine. The findings provide valuable insights into the responses of yarrow plants to salinity stress and highlight the potential of spermidine in mitigating the adverse effects of salinity stress.

Composition characterization and biological activity study of Achillea vermicularis extract and extract-loaded nanoparticles.

Antiproliferative activity of Achillea vermicularis extracts was calculated on glial (C6) and keratinocyte (HaCaT) cell lines using XTT assay. It was observed that all extracts of A. vermicularis at the determined concentration were not cytotoxic in HaCaT cell lines. The nanoparticles (NPs) of the extract with the best cytotoxic activity was prepared, and necessary characterization studies were performed. Results showed that NP containing the extract has a lower IC50 value and more cytotoxic activity in C6 cells compared to the only extract. Furthermore, the antiepileptic potentials of these substances were explored in this study. The effect of A. vermicularis extracts on the enzyme activities of carbonic anhydrase I and II isoenzymes (hCA I and hCA II) was measured using spectrophotometry to achieve this goal. A. vermicularis extracts demonstrated high inhibitory activities compared to standard inhibitor (acetazolamide, AAZ), with IC50 values in the range of 5.04-10.8 µg/ml for hCA I, and 5.40-9.22 µg/ml for hCA II. High-performance liquid chromatography diode array detector (HPLC-DAD) was used in this investigation to assess the main chemicals found in the extract and NPs. The results showed that the ethanol extract (157.636 µg/mg extract) and NPs (4.631 µg/mg extract) had a significant amount of the 8-hydroxy salvigenin component.

Achillea millefolium Essential Oil Mitigates Peptic Ulcer in Rats through Nrf2/HO-1 Pathway.

Extreme ethanol ingestion is associated with developing gastric ulcers. Achillea millefolium (yarrow) is one of the most commonly used herbs with numerous proven pharmacological actions. The goal of the hereby investigation is to explore the gastroprotective action of yarrow essential oil against ethanol-induced gastric ulcers and to reveal the unexplored mechanisms. Rats were distributed into five groups (n = 6); the control group administered 10% Tween 20, orally, for two weeks; the ethanol group administered absolute ethanol (5 mL/kg) to prompt gastric ulcer on the last day of the experiment. Yarrow essential oil 100 or 200 mg/kg + ethanol groups pretreated with yarrow oil (100 or 200 mg/kg, respectively), orally, for two weeks prior to gastric ulcer induction by absolute ethanol. Lanso + ethanol group administered 20 mg/kg lansoprazole, orally, for two weeks prior to gastric ulcer induction by ethanol. Results of the current study showed that ethanol caused several macroscopic and microscopic alterations, amplified lipid peroxidation, pro-inflammatory cytokines, and apoptotic markers, as well as diminished PGE2, NO, and antioxidant enzyme activities. On the other hand, animals pretreated with yarrow essential oil exhibited fewer macroscopic and microscopic modifications, reduced ulcer surface, and increased Alcian blue binding capacity, pH, and pepsin activity. In addition, yarrow essential oil groups exhibited reduced pro-inflammatory cytokines, apoptotic markers, and MDA, restored the PGE2 and NO levels, and recovered the antioxidant enzyme activities. Ethanol escalated Nrf2 and HO-1 expressions, whereas pretreatment of yarrow essential oil caused further intensification in Nrf2 and HO-1. To conclude, the current study suggested yarrow essential oil as a gastroprotective agent against ethanol-induced gastric lesions. This gastroprotective effect could be related to the antioxidant, anti-inflammatory, and anti-apoptotic actions of the essential oil through the instigation of the Nrf2/HO-1 pathway.

Three New Acrylic Acid Derivatives from Achillea mellifolium as Potential Inhibitors of Urease from Jack Bean and α-Glucosidase from Saccharomyces cerevisiae.

(1) Background: Achillea mellifolium belongs to a highly reputed family of medicinal plants, with plant extract being used as medicine in indigenous system. However, limited data is available regarding the exploitation of the medicinal potential of isolated pure compounds from this family; (2) Methods: A whole plant extract was partitioned into fractions and on the basis of biological activity, an ethyl acetate fraction was selected for isolation of pure compounds. Isolated compounds were characterized using different spectroscopic techniques. The compounds isolated from this study were tested for their medicinal potential using in-vitro enzyme assay, coupled with in-silico studies; (3) Results: Three new acrylic acid derivatives (1-3) have been isolated from the ethyl acetate fraction of Achillea mellifolium. The characterization of these compounds (1-3) was carried out using UV/Vis, FT-IR, 1D and 2D-NMR spectroscopy (1H-NMR, 13C-NMR, HMBC, NOESY) and mass spectrometry. These acrylic acid derivatives were further evaluated for their enzyme inhibition potential against urease from jack bean and α glucosidase from Saccharomyces cerevisiae, using both in-silico and in-vitro approaches. In-vitro studies showed that compound 3 has the highest inhibition against urease enzyme (IC50 =10.46 ± 0.03 µΜ), followed by compound 1 and compound 2 with percent inhibition and IC50 value of 16.87 ± 0.02 c and 13.71 ± 0.07 µΜ, respectively, compared to the standard (thiourea-IC50 = 21.5 ± 0.01 µΜ). The investigated IC50 value of compound 3 against the urease enzyme is two times lower compared to thiourea, suggesting that this compound is twice as active compared to the standard drug. On the other hand, all three compounds (1-3) revealed mild inhibition potential against α-glucosidase. In-silico molecular docking studies, in combination with MD simulations and free energy, calculations were also performed to rationalize their time evolved mode of interaction inside the active pocket. Binding energies were computed using a MMPBSA approach, and the role of individual residues to overall binding of the inhibitors inside the active pockets were also computed; (4) Conclusions: Together, these studies confirm the inhibitory potential of isolated acrylic acid derivatives against both urease and α-glucosidase enzymes; however, their inhibition potential is better for urease enzyme even when compared to the standard.

Germacranolide- and guaianolide-type sesquiterpenoids from Achillea alpina L. reduce insulin resistance in palmitic acid-treated HepG2 cells via inhibition of the NLRP3 inflammasome pathway.

Chemical investigation on the aerial part of Achillea alpina L. led to the isolation of twenty sesquiterpenoids. The structures of the undescribed achigermalides A-H were determined by extensive spectroscopic analysis, including NMR, HRESIMS, UV and IR, and their absolute configurations were established by computational electronic circular dichroism (ECD) method. The X-ray crystal structure for 8α-angeloxy-1ß,2ß:4ß,5ß-diepoxy-10ß-hydroxy-6ßH,7αH,11ßH-12,6α-guaianolide was reported for the first time. Glucose consumption was analyzed to investigate the effect of all compounds on palmitic acid (PA)-mediated insulin resistance (IR) in HepG2 cells, and achigermalides D-F, desacetylherbohde A, and 4E,10E-3-(2-methylbutyroyloxy)-germacra-4,10(1)-diene-12,6α-olide appreciably enhanced the glucose consumption at low concentrations of 1.56-6.25 µM. Moreover, achigermalide D decreased the expression of IL-1ß and the generation of reactive oxygen species (ROS), and also down-regulated the protein levels of TXNIP, NLRP3, caspase-1 and NF-κB in the Western blot analysis, suggesting achigermalide D mediated IR via the suppression of NLRP3 inflammasome pathway.

Brain transcriptomic responses of Yarrow's spiny lizard, Sceloporus jarrovii, to conspecific visual or chemical signals.

Species with multimodal communication integrate information from social cues in different modalities into behavioral responses that are mediated by changes in gene expression in the brain. Differences in patterns of gene expression between signal modalities may shed light on the neuromolecular mechanisms underlying multisensory processing. Here, we use RNA-Seq to analyze brain transcriptome responses to either chemical or visual social signals in a territorial lizard with multimodal communication. Using an intruder challenge paradigm, we exposed 18 wild-caught, adult, male Sceloporus jarrovii to either male conspecific scents (femoral gland secretions placed on a small pebble), the species-specific push-up display (a programmed robotic model), or a control (an unscented pebble). We conducted differential expression analysis with both a de novo S. jarrovii transcriptome assembly and the reference genome of a closely related species, Sceloporus undulatus. Despite some inter-individual variation, we found significant differences in gene expression in the brain across signal modalities and the control in both analyses. The most notable differences occurred between chemical and visual stimulus treatments, closely followed by visual stimulus versus the control. Altered expression profiles could explain documented aggression differences in the immediate behavioral response to conspecific signals from different sensory modalities. Shared differentially expressed genes between visually- or chemically-stimulated males are involved in neural activity and neurodevelopment and several other differentially expressed genes in stimulus-challenged males are involved in conserved signal-transduction pathways associated with the social stress response, aggression and the response to territory intruders across vertebrates.

Comparison of the Phenolic Compound Profile and Antioxidant Potential of Achillea atrata L. and Achillea millefolium L.

In the present study, Achillea atrata L. and A. millefolium L. were compared for the first time with regard to their phenolic compound profile and antioxidant activity by applying the 2,2-diphenyl-picryl hydrazyl radical assay. For this purpose, aerial plant parts were consecutively extracted with solvents of increasing polarity (dichloromethane, n-butanol, ethyl acetate), revealing that the A. atrata ethyl acetate fraction showed the highest antioxidant activity with an IC50 value of 12.2 ± 0.29 µg/mL compared to 17.0 ± 0.26 µg/mL for A. millefolium. Both species revealed the presence of luteolin, apigenin, centaureidin, and nevadensin exclusively in this most polar fraction, which are known as effective 2,2-diphenyl-picryl hydrazyl radical scavengers. The antioxidant capacity of the aforementioned fractions strikingly correlated with their total phenolic contents, which was highest in the ethyl acetate fraction of A. atrata. Characterization of the metabolite profiles of both Achillea species showed only marginal differences in the presence of key compounds, whereas the concentrations of individual compounds appeared to be species-specific. Our results suggest that A. atrata, based on its compound pattern and bioactivity characteristics, has similar qualities for phytotherapy as A. millefolium.

Heat priming improved heat tolerance of photosynthesis, enhanced terpenoid and benzenoid emission and phenolics accumulation in Achillea millefolium.

The mechanism of heat priming, triggering alteration of secondary metabolite pathway fluxes and pools to enhance heat tolerance is not well understood. Achillea millefolium is an important medicinal herbal plant, rich in terpenoids and phenolics. In this study, the potential of heat priming treatment (35°C for 1 hr) to enhance tolerance of Achillea plants upon subsequent heat shock (45°C for 5 min) stress was investigated through recovery (0.5-72 hr). The priming treatment itself had minor impacts on photosynthesis, led to moderate increases in the emission of lipoxygenase (LOX) pathway volatiles and isoprene, and to major elicitation of monoterpene and benzaldehyde emissions in late stages of recovery. Upon subsequent heat shock, in primed plants, the rise in LOX and reduction in photosynthetic rate (A) was much less, stomatal conductance (gs ) was initially enhanced, terpene emissions were greater and recovery of A occurred faster, indicating enhanced heat tolerance. Additionally, primed plants accumulated higher contents of total phenolics and condensed tannins at the end of the recovery. These results collectively indicate that heat priming improved photosynthesis upon subsequent heat shock by enhancing gs and synthesis of volatile and non-volatile secondary compounds with antioxidative characteristics, thereby maintaining the integrity of leaf membranes under stress.

Identification of Transient Receptor Potential Vanilloid 3 Antagonists from Achillea alpina L. and Separation by Liquid-Liquid-Refining Extraction and High-Speed Counter-Current Chromatography.

Bioassay-guided fractionation of the ethanol extract of whole herbs of Achillea alpina led to the isolation of isochlorogenic acids A and B as transient receptor potential vanilloid 3 (TRPV3) channel antagonists by using a calcium fluorescent assay. The structures were identified by spectroscopic analysis and the inhibitory activities of isochlorogenic acids A and B were confirmed by whole-cell patch clamp recordings of human embryonic kidney 293 (HEK293) cells expressing human TRPV3. Molecular docking results revealed that these two compounds reside in the same active pocket of human TRPV3 channel protein with lower binding energy than the agonist 2-aminoethoxydiphenyl borate (2-APB). High-speed counter-current chromatography (HSCCC) coupled with a liquid-liquid extraction approach was successfully established for the separation of isochlorogenic acids A and B from the whole herbs of A. alpina. Ethyl acetate and n-hexane-ethyl acetate-water (3:3:4 and 1:5:4, v/v/v) were selected as liquid-liquid extraction solvent systems to remove high- and low-polarity impurities in the mixture. Sixty g of ethanol extract was refined by solvent partition to yield 1.7 g of the enriched fraction, of which 480 mg in turn obtained 52.5 mg of isochlorogenic acid B (purity 98.3%) and 37.6 mg isochlorogenic acid A (purity 96.2%) after HSCCC with n-hexane-ethyl acetate-water containing 1% acetic acid (1:4:8, v/v/v).

Green synthesis of silver nanoparticles and their applications as an alternative antibacterial and antioxidant agents.

Antimicrobial resistance is a complex global health challenge today. Discovery and development of new natural alternates with novel targets is utmost priority. In this experiment, alternative antibiotic agents in the form of silver nanoparticles (SNPs) and Achillea millefolium L. extracts were evaluated for antibacterial and antioxidant activity. The SNPs were synthesized using aqueous, ethanol and methanol extracts of A. millefolium and were monitored by a color change and UV-vis spectroscopy. The size and shape of the nanoparticles were determined through scanning electron microscopy and phase was assessed through X-ray diffraction. The SNPs were shown to have an average diameter of 20.77, 18.53 and 14.27 nm with spherical, rectangular and cubical shapes, synthesized from aqueous, ethanol and methanol extract respectively. The response of biomolecules present in plant extract during the formation of SNPs was analyzed by Fourier transform infrared spectrometry, showing polyphenols, proteins, carboxylic acid and alcohol are involved in the formation of SNPs. The plant extracts and SNPs were then studied for their antibacterial potential against common human pathogens such as gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and gram-negative bacteria (Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa), displaying a very good activity against both types of bacteria. The Methanol-SNPs exhibit greater inhibition of DPPH radicals with IC50 7.03 ± 0.31 µg/mL. This green method of synthesis of SNPs would support the production of SNPs with considerably boosted antibacterial and antioxidant properties and significantly enhanced therapeutic performance.

Nanoemulsions and acidified milk gels as a strategy for improving stability and antioxidant activity of yarrow phenolic compounds after gastrointestinal digestion.

The aim of this study was to improve the stability and antioxidant activity of yarrow phenolic compounds upon an in vitro simulated gastrointestinal digestion. Therefore, two types of caseins-based delivery systems, sodium caseinate stabilized nanoemulsions (NEs) and glucono delta-lactone acidified milk gels (MGs), were formulated containing an ultrasound-assisted yarrow extract (YE) at two concentrations (1 and 2.5 mg/mL). Formulations with 1 mg/mL of YE were chosen based on their higher encapsulation efficiency to perform the in vitro digestion experiments. After digestion, YE-loaded NEs only partially protected phenolic compounds from degradation; meanwhile the phenolic composition of YE including in MGs after digestion was quite similar to undigested YE. Moreover, the antioxidant activity of MGs after digestion was higher than NEs digested samples, which confirms the higher protection of YE phenolic compound by the milk gels systems. This research demonstrated the potential use of acidified MGs as carriers to improve the stability and antioxidant activity of yarrow phenolic compounds. Therefore, these matrices could be employed to develop new dairy products enriched with phenolic compounds.

Geochemical (soil) and phylogenetic (plant taxa) factors affecting accumulation of macro- and trace elements in three natural plant species.

A field study was carried out to estimate the variations in the concentrations of macro- and trace elements in the rhizosphere soil and in roots and leaves of three widely distributed plant species-couch grass, plantain, and yarrow collected simultaneously from two sites characterized by different soil parameters. Main attention was paid to environmental (soil characteristics) and phylogenetic (plant species) factors that can influence on the concentrations of different elements in the plants and in soils. Both the factors cannot be considered as independent, although their contribution to the plant elemental composition may be different. There were statistically significant differences between concentrations of C, N, and H and 13 macro- and trace elements in the soils collected from the two sites. The concentrations of many chemical elements in the rhizosphere soil of the three plant species collected from the same site were often different. The differences in the characteristics of the soils at the sites resulted in differences between the concentrations of several elements in the plants growing at the sites. However, this was only one of the reasons of significant difference between the concentrations of macro- and trace elements in the same plant species collected from the sites. Couch grass, plantain, and yarrow had different reactions on the soil characteristics. The elemental composition of each plant species was unique although they grew at the same place and were collected simultaneously. Among the plants, yarrow was more tolerant to varying environmental conditions than plantain and couch grass.

Effect of shading and nitrogen fertilization on nitrogen metabolism, essential oil content and antimicrobial activity of Achillea millefolium

The Achillea millefolium L. is a perennial herb with important antibacterial, antifungal, anti-inflammatory, antitumoral, and antioxidant properties. This research aimed to investigate the effect of shading (75%; black net) and nitrogen fertilization (0, 75 and 150 kg urea ha-1) on the nitrogen metabolism, essential oil yield and antimicrobial activity of A.millefolium at vegetative- and reproductive-stage. The evaluated parameters varied depending on the organ and the phenological stage of the plant considered. Overall, our findings indicated that shading decreased nitrogen assimilation. Decreased activities of nitrate reductase and glutamine synthetase were observed on shaded plants during reproductive and vegetative stages, respectively. Nitrate and total amino acid levels increased in shaded plants at the vegetative stage. Regarding nitrogen supply, the improved nitrogen metabolism and essential oil yield values were accompanied by intermediate concentrations of urea (75 kg ha-1). Plants fertilized with 75 kg urea ha-1 produced the highest amino acids concentration (vegetative stage), ammonium concentration (vegetative stage) and essential oil yield (reproductive stage). Shading or nitrogen supply did not influence the microbial activity of A. millefolium essential oil.However, the essential oil of leaves and flowers were highly effective against fungi and bacteria, especially gram-positive bacteria. In conclusion, the current study showed that full light and 75 kg urea ha-1 enhanced the nitrogen metabolism of A. millefolium in both vegetative and reproductive stages.

Evaluation of Phytochemical Compositions and Biological Properties of Achillea gypsicola at Different Phenological Stages.

Phytochemicals, which are commonly found at different levels in many medicinal plants, are natural strong antioxidants used in traditional medicine. In this research, determination of differences of phytochemical compositions and biological properties were aimed as periodically (pre-, full and post flowering) and daily (6 am, 1 pm and 8 pm) in Achillea gypsicola Hub.-Mor. The volatile oils belonging to A. gypsicola were obtained by hydrodistillation and analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC/MS). The antimicrobial activities of the volatile oils were determined with disc diffusion method. The microdilution method was used to determine minimum inhibitory concentration (MIC). Total phenolic and flavonoid contents were determined by spectrophotometric methods and antioxidant capacities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical, reducing power (RP) and metal chelating activity (MCA) assay. In addition, the phenolic acid and flavonoid compositions were evaluated by reversed phase-high-performance liquid chromatography (RP-HPLC). This study presented a comprehensive report for the first time on evaluation of the phytochemical composition and the biological properties of A. gypsicola at different phenological stages. Thirty-two compounds, containing the major component as camphor, 1,8-cineole and borneol, were detected. Designated harvest time for the highest yield of volatile oils was found to be at full flowering stage-1 pm. It has been observed that the volatile oil composition changes periodically and even daily. Also, in this research, menthol and menthone were found as the composition of volatile oil in Achillea species for the first time. Full flowering stage was found as the richest period in terms of phenolic acid and flavonoid compositions of A. gypsicola for the first time. The species examined in this research showed a high antioxidant and antimicrobial activity in comparison to other studies with Achillea species. The volatile oils exhibited high performances with range of inhibition zones (8.3-42.3 mm) and minimum inhibitory concentration values (2.25-144 µg/ml). Besides, a high correlation between antioxidant activity and phenolic content of A. gypsicola was found. These results suggest that A. gypsicola can be used as a safe source in the cosmetic, food and pharmaceutical industries.

Chemical Composition and Antimicrobial Activity of Achillea tenuifolia Lam. Essential Oil at Different Phenological Stages from Khoy.

Achillea species and in particular Achillea tenuifolia Lam. is generally used as a food flavor and traditional remedies, especially in the initial developmental stage for medical conditions in the Mediterranean part of Iran. In this report, we extracted the essential oil from the aerial parts of A. tenuifolia (collected from Khoy), at various developmental stages (i. e., vegetative, flowering and fruiting), characterized them and studied their antibacterial activities. Of 46, 51 and 38 components found in the vegetative, flowering, and fruiting stages, respectively, 35 were present in all three stages, including oxygenated terpenes such as carvacrol (30.85-34.11), germacrene C (16.21-17.87), spathulenol (7.26-8.96), ß-sesquiphellandrene (4.11-4.25), τ-muurolol (2.27-3.25) and α-cadinol (2.01-3.29). We witnessed that the composition of the essential oils varies with phenological stages and geographic regions. The essential oil demonstrated substantial antibacterial properties against both Gram-positive and Gram-negative bacteria, indicated by disk method, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. Except Pseudomonas aeruginosa, the essential oils of various phenological stages showed higher antibacterial activity against tested bacteria, with Bacillus anthracis as the most sensitive strain. Moreover, although antibacterial characteristics of the essential oil from the vegetative and flowering stages were similar (p=0.91), they were significantly different from those of fruiting stage (p<0.005 in both MIC and MBC tests). This emphasizes the importance of the developmental stage of the plant in the biological properties of its essential oil and justifies the widespread application of this plant in the vegetative stage.

The spatio-temporal expression of some genes involved in the biosynthetic pathways of terpenes/phenylpropanoids in yarrow (Achillea millefolium).

Yarrow (Achillea millefolium) is a medicinal plant from the Asteracea which biosynthesize different secondary metabolites especially terpenes and phenylpropanoids. To improve our understanding of the regulatory mechanisms behind the biosynthesis of these compounds we analyzed the expression of some genes associated with the biosynthesis of terpenes and phenylpropanoids in different tissues and in response to trans-cinnamic acid (tCA) as an inhibitor of PAL activity. Isolation and expression analysis of DXR, GPPS, PAL and CHS genes together with linalool synthase (LIS) as monoterpene synthase was conducted in different developmental stages of leaves, flowers and in response to trans-cinnamic acid (tCA). Differential expression of these genes observed in different tissues. tCA up-regulated the biosynthetic genes of monterpenes and down-regulated the biosynthetic genes of phenylpropanoids. Gene expression analysis in intact leaves and leaves without glandular trichomes showed that DXR, LIS, PAL and CHS are highly expressed in glandular trichomes while GPPS expressed ubiquitously. Analysis of essential oils composition showed that sesquiterpenes and monoterpenes are main compounds; in which from 57 identified compounds the highest were germacreneD (% 11.5), guaiol (%10.38), spatulenol (%8.73) and caryophyllene oxide (%7.48).

The effect of drought stress on polyphenolic compounds and expression of flavonoid biosynthesis related genes in Achillea pachycephala Rech.f.

This study investigated the effect of drought stress on the amount of phenolic and flavonoid compounds as well as H2O2 and malondialdehyde (MDA) in Achillea pachycephala. The expression patterns of the key genes and their molecular mechanisms in the phenylpropanoid pathway (PAL, CHS, CHI, F3H, F3'H, F3'5'H, FLS) were also assessed during drought stress using quantitative real-time polymerase chain reaction (qRT-PCR). The samples were harvested at 0, 7, 14, 21 and 28 days after exposure to drought stress. High-performance liquid chromatography (HPLC) analysis was performed to determine the changes of phenolic and flavonoid compounds - chlorogenic acid, caffeic acid, rutin, luteolin-7-O-glycoside, 1,3-dicaffeoylquinic acid, apigenin-7-O-glycoside, luteolin, apigenin and kaempferol - during stress conditions. Concentrations of most of the compounds increased with increasing drought stress duration. Most of the phenolic acids continued to accumulate with increasing duration of stress, while flavonoids dramatically decreased at day 28 of stress. Chlorogenic acid was the most abundant phenolic acid (4.97 mg/100 g dry weight [DW]) at the beginning of the experiment, while it decreased at day 7 and increased again at day 21. However, different trends were observed for some flavonoids, such as luteolin and apigenin. At the beginning of stress treatment, high accumulation of free radicals (H2O2) and lipid peroxidation (MDA) led to elevated expression of most of the flavonoid genes. MDA increased from 22.66 to 43.28 µmol g-1 DW at day 28. CHS gene expression was elevated at day 7, while chi gene expression remained unchanged. At the end of the stress period, most of the flavonoid concentrations and expression of the relevant genes also increased. The results can facilitate selection of appropriate drought conditions to obtain the highest levels of flavonoids such as luteolin and apigenin and phenolic compounds such as chlorogenic acid for improved health benefits.

Yarrow supercritical extract exerts antitumoral properties by targeting lipid metabolism in pancreatic cancer.

Metabolic reprogramming is considered a hallmark of cancer. Currently, the altered lipid metabolism in cancer is a topic of interest due to the prominent role of lipids regulating the progression of various types of tumors. Lipids and lipid-derived molecules have been shown to activate growth regulatory pathways and to promote malignancy in pancreatic cancer. In a previous work, we have described the antitumoral properties of Yarrow (Achillea Millefolium) CO2 supercritical extract (Yarrow SFE) in pancreatic cancer. Herein, we aim to investigate the underlaying molecular mechanisms by which Yarrow SFE induces cytotoxicity in pancreatic cancer cells. Yarrow SFE downregulates SREBF1 and downstream molecular targets of this transcription factor, such as fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD). Importantly, we demonstrate the in vivo effect of Yarrow SFE diminishing the tumor growth in a xenograft mouse model of pancreatic cancer. Our data suggest that Yarrow SFE can be proposed as a complementary adjuvant or nutritional supplement in pancreatic cancer therapy.

Chemical Composition and Antibacterial Activity of the Bulgarian Endemic Species Achillea thracica from its Natural Habitat, and in vitro Propagated and ex vitro Established Plants.

The present study reports the chemical composition of headspace volatiles (HS) and acetone extracts of the endemic Bulgarian species Achillea thracica Velen. from its natural habitat (N), in vitro propagated (IN) and ex vitro established (EX) plants. Additionally, acetone extracts were tested by a disk diffusion method for antibacterial activity. Irregular monoterpenes were the most abundant HS volatile constituents, while 0,0-dimethyl quercetin was the most abundant flavonoid in the acetone extracts. The secondary metabolites of A. thracica grown in its natural habitat (N), propagated in vitro (IN) and ex vitro established (EX) showed that the qualitative composition is mutually similar, but there are differences in the quantitative composition. Considering antibacterial activity, IN and EX samples showed moderate activity against Pseudomonas aeruginosa and Escherichia coli.

Differential allelopathic expression of different plant parts of Achillea biebersteinii.

Achillea biebersteinii (Asteraceae) is a perennial medicinal plant and has a wide distributional range in the Mediterranean region. The present study investigated the inhibitory effects of different plant parts of A. biebersteinii on germination characteristics and seedling growth of wild barley (Hordeum spontaneum). Water extracts were prepared by incubating separately five grams of dried powder of roots, stems, leaves and flowers of A. biebersteinii in 100 ml of distilled water for 24 h and distilled water was used as the control. The water extracts from different plant parts of A. biebersteinii differed in their effects on the germination and seedling growth of wild barley. Water extracts prepared from leaves and flowers were more suppressive to germination of wild barley than root and stem extracts. The maximum inhibition in radical and plumule growth of germinating caryopses and in root and shoot growth of greenhouse-grown wild barley was recorded for leaf extract followed by flower extract. The lowest Chl a, Chl b and total chlorophyll and protein contents were resulted after exposure to leaf extracts. According to these results, the inhibitory effects of different A. biebersteinii plant parts can be arranged in the order: leaf > flower > stem > root.