Phytochemistry and Evidence-Based Traditional Uses of the Genus Achillea L.: An Update (2011–2021)

Silver nanoparticles synthesized using aerial part of Achillea fragrantissima and evaluation of their bioactivities

Achillea fragrantissima (A. fragrantissima), a desert plant, is used internally in Arabian traditional medicine to treat inflammatory, spasmodic gastrointestinal disorders, and hepatobiliary diseases. The study focuses on the environmentally friendly production of silver nanoparticles (AgNPs) from the water-based aerial parts of the A. fragrantissima plant and their ability to kill bacteria and cells. Ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) were used to describe the AgNPs. They were then tested for their ability to fight cancer and bacteria. A change in colour from yellow to brown and a surface plasmon resonance peak at 440 nm, seen with UV-Vis spectroscopy, showed that AgNPs had formed. In a Gas Chromatography-Mass Spectrometry (GC-MS) test of the aerial parts of A. fragrantissima, twenty bioactive components were found. These included isolongifolol and 3E,10Z-Oxacyclotrideca-3,10-diene-2,7-dione, methylbuta-1,3-dienyl)-7-oxabicyclo [4.1.0] heptan-3-ol. The extract exhibited high phenolic and flavonoid content (77.52 ± 1.46 mg GAE/g dry weight and 59 ± 2.17 mg QE/g dry weight, respectively). According to the IC50 values of 17.2 ± 1.18 and 14 ± 2.43 µg/mL, the AgNPs had a lot of power to kill cancer cells from the MCF-7 and HepG2 lines. Some genes that cause cell death (caspase-3, 8, 9, and Bax) were turned on more in the treated cells compared to the control cells that had not been treated. These genes were Bcl-xL and Bcl-2. Additionally, substantial activity against both Gram-positive bacteria and Gram-negative bacteria was found by antibacterial screening. Overall, this study underscores A. fragrantissima's diverse biological activity and its potential in drug discovery and nanomedicine, promoting the development of natural antibacterial and anticancer therapies.

Terpenoids and steroids from aerial parts of Achillea alpina L. as PTP1B inhibitors: Kinetic analysis and molecular docking studies

Achillea alpina L. (Alpine yarrow) is a noteworthy herb in the genus Achillea with many uses in vegetables and traditionally used to treat stomach disorders. In our continuous research on the chemical constituents and biological activities of medicinal plants, ten previously undescribed terpenoids including eight eudesmane-type sesquiterpenes (1-8), one nor-eudesmane-type sesquiterpene (9), one cyclo-geraniol derivative (10), and twenty-one known compounds were isolated and structurally elucidated from the aerial parts of A. alpina. Structures and absolute configurations of the undescribed terpenoids were identified using comprehensive spectroscopic analysis (NMR, HRESI-MS, and CD data) and computational methods (ECD and NMR calculation). Enzyme inhibitory assays showed that the isolated sesquiterpene (19), triterpene (22), and sterol (26) were protein tyrosine phosphatase 1B (PTP1B) inhibitors with IC50 values ranging from 14.87 to 23.09 μM in comparison with positive control - ursolic acid, showing IC50 value of 5.93 ± 0.16 μM. Further enzyme kinetics and molecular docking studies were performed to provide valuable insights into their mechanism of action.

Study on the metabolism of natural sesquiterpene lactones in human liver microsomes using LC-Q-TOF-MS/MS

Sesquiterpene lactones are naturally occurring, highly active -specialised metabolites, which are biosynthesized by important medicinal plants, fulfilling many functions. The in vitro metabolism of parthenolide (1), grosheimin (2), carbetolide C (3), 8α-O-(3,4-dihydroxy--methylenebutanoyloxy)-dehydromelitensin (4) and arteludovicinolide A (5) was examined using human liver microsomes. Phase I, phase II (glucuronidation), as well as combined phase I + II metabolism were studied. Metabolites were identified via liquid chromatography-high resolution quadrupole time-of-flight mass spectrometry. Monohydroxylated, hydrated, carboxylated, methylated derivatives, together with corresponding monoglucuronides were detected, suggesting that the metabolism of sesquiterpene lactones is changeable due to structural features and scaffold diversity, though the lactone ring is the main site of metabolism.

Herb and Flowers of Achillea millefolium subsp. millefolium L.: Structure and Histochemistry of Secretory Tissues and Phytochemistry of Essential Oils

Achillea millefolium L. herb and flowers have high biological activity; hence, they are used in medicine and cosmetics. The aim of this study was to perform morpho-anatomical analyses of the raw material, including secretory tissues, histochemical assays of the location of lipophilic compounds, and quantitative and qualitative analysis of essential oil (EO). Light and scanning electron microscopy techniques were used to analyse plant structures. The qualitative analyses of EO were carried out using gas chromatography-mass spectrometry (GC/MS). The results of this study showed the presence of exogenous secretory structures in the raw material, i.e., conical cells (papillae) on the adaxial surface of petal teeth and biseriate glandular trichomes on the surface flowers, bracts, stems, and leaves. Canal-shaped endogenous secretory tissue was observed in the stems and leaves. The histochemical assays revealed the presence of total, acidic, and neutral lipids as well as EO in the glandular trichome cells. Additionally, papillae located at the petal teeth contained neutral lipids. Sesquiterpenes were detected in the glandular trichomes and petal epidermis cells. The secretory canals in the stems were found to contain total and neutral lipids. The phytochemical assays demonstrated that the A. millefolium subsp. millefolium flowers contained over 2.5-fold higher amounts of EO (6.1 mL/kg) than the herb (2.4 mL/kg). The EO extracted from the flowers and herb had a similar dominant compounds: β-pinene, bornyl acetate, (E)-nerolidol, 1,8-cineole, borneol, sabinene, camphor, and α-pinene. Both EO samples had greater amounts of monoterpenes than sesquiterpenes. Higher amounts of oxygenated monoterpenes and oxygenated sesquiterpenoids were detected in the EO from the herb than from the flowers.

Potential Treatment of Dermatophyte Trichophyton rubrum in Rat Model Using Topical Green Biosynthesized Silver Nanoparticles with Achillea santolina Extract

Trichophyton rubrum is the most common dermatophyte, and can cause cutaneous infections in humans and animals (dermatophytosis). In this study, we investigated the anti-dermatophytic potential of green synthesized silver nanoparticles using Achillea santolina extract (AS-AgNPs) in an in vitro and in vivo rat model of dermal T. rubrum dermatophytosis (TRD). The green synthesis of AS-AgNPs was performed using A. santolina extract and characterized by UV-VIS spectroscopy, zeta potential, imaging (transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Energy dispersive X-ray analysis (EDX). The antifungal activity of AS-AgNPs was determined by the broth microdilution method, conidial germination, and hyphal growth inhibition. TEM and SEM were used to study the mode of the antifungal action of AS-AgNPs. AS-AgNPs inhibited the growth of T. rubrum with an MIC of 128 μg/mL, and suppressed the conidial germination and hyphal growth by 55.3% 84.6%, respectively. AS-AgNPs caused modified mycelial structures, increased cell membrane permeability, and cell wall damage. AS-AgNPs significantly increase the permeability of the fungal membrane, as revealed by reducing ergosterol biosynthesis. An increase in the intracellular ROS and the induction of apoptosis were also observed during AS-AgNP treatment. In addition, AS-AgNPs reduced the cell wall integrity, as shown by the reduction in the β-(1,3)-d-glucan synthase and chitin synthase activities. AS-AgNPs showed very low toxicity on primary human dermal fibroblasts (HDF) at the MIC. The topical treatment of the infected skin in the TRD rat model with AS-AgNPs showed a significant reduction in the fugal burden after 7 days and a complete clearance of fungal conidia, with a high recovery of epidermal and dermal structures after 14 days, compared to control rats. Interestingly, AS-AgNPs significantly attenuated the infiltrated inflammatory cells, in association with reducing the tissue proinflammatory cytokines including TNF-α, IL-1, IL-6, MOP and IL-17. In conclusion, our data prove AS-AgNPs to be a novel green topical therapy for dermatophytosis caused by T. rubrum.

Bioavailability Assessment of Yarrow Phenolic Compounds Using an In Vitro Digestion/Caco-2 Cell Model: Anti-Inflammatory Activity of Basolateral Fraction

In this study, a combined in vitro digestion/Caco-2 model was performed with the aim to determine the phenolic compounds bioavailability of two yarrow extracts. HPLC-PAD characterisation indicated that the main components in both extracts were 3,5-dicaffeoylquinic acid (DCQA) and luteolin-7-O-glucoside. Analyses after the simulated digestion process revealed that phenolic composition was not affected during the oral phase, whereas gastric and intestinal phases represented critical steps for some individual phenolics, especially intestinal step. The transition from gastric medium to intestinal environment caused an important degradation of 3,5-DCQA (63-67% loss), whereas 3,4-DCQA and 4,5-DCQA increased significantly, suggesting an isomeric transformation within these caffeic acid derivatives. However, an approx. 90% of luteolin-7-O-glucoside was recovered after intestinal step. At the end of Caco-2 absorption experiments, casticin, diosmetin and centaureidin represented the most abundant compounds in the basolateral fraction. Moreover, this fraction presented anti-inflammatory activity since was able to inhibit the secretion of IL-1β and IL-6 pro-inflammatory cytokines. Thus, the presence in the basolateral fraction of flavonoid-aglycones from yarrow, could be related with the observed anti-inflammatory activity from yarrow extract.

Digestive and gastroprotective effects of Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae): From traditional uses to preclinical studies

ETHNOPHARMACOLOGICAL RELEVANCE

Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae) is an alpine endemic plant whose aerial parts are harvested by the locals mainly for the digestive properties. Despite its widespread use, few studies have been conducted to date to verify its bioactivity.

AIM OF THE STUDY

The purpose of the work was to meet the tradition confirming with experimental data the popular belief that the consumption of this species offers beneficial effects to the gastrointestinal system.

MATERIALS AND METHODS

Using Soxhlet apparatus, the dried aerial parts of A. erba-rotta subsp. moschata were successively extracted with petroleum ether (PET), dichloromethane (DCM) and methanol (MeOH). The essential oil (EO) was obtained by hydrodistillation using a Clevenger apparatus while infusion (AE) was prepared following the traditional local recipe. Their chemical characterization was performed by various techniques including SPME-GC/MS, GC/MS and HPLC/MS-MS. An in vitro biological screening was carried out. The influence of AE on lipid digestion was monitored by titration of free fatty acids (FFA) during pancreatic lipase activity with the pH-stat method. For all extracts and EO, the anti-Helicobacter pylori activity was assessed by the broth microdilution method, the influence on cell viability was evaluated against NCI-N87, OE21 and Caco-2 cell lines and a preliminary toxicity evaluation was done using Brine Shrimp lethality (BSL) assay. The anti-inflammatory potential was evidenced by interleukin IL-1- induced IL8 expression on Caco-2 cells.

RESULTS

AE increased by 15% the FFA releasing compared to the pancreatic lipase alone. PET, DCM and MeOH extracts as well as AE and EO were considered active against the growth of both antimicrobial susceptible and resistant strains of H. pylori with MIC values starting from 16 μg/mL. PET and DCM (IC₅₀ = 89 μg/mL and 96 μg/mL, respectively, against Caco-2 cell line) extracts showed the high effect on cell viability while the EO reduced in 50% of cell viability at 1.48 μL/mL (NCI-N87 cells), 1.42 μL/mL (OE21 cells), and 3.44 μL/mL (Caco-2 cells) corroborating the BSL results. In different degrees, all extracts and EO inhibited the IL-1β-stimulated IL-8 production in Caco-2 cells.

CONCLUSIONS

The obtained data are encouraging and provide a scientific basis for the traditional use of A. erba-rotta subsp. moschata as a digestive agent although they need to be further corroborated by studies involving the investigation of both the in vivo activities and the role of the compounds detected in the extracts.

Antioxidant, Anti-Inflammatory, and Antibacterial Properties of an Achillea millefolium L. Extract and Its Fractions Obtained by Supercritical Anti-Solvent Fractionation against Helicobacter pylori

The main objective of this work is to evaluate the potential utility of an Achillea millefolium extract (yarrow extract, YE) in the control of H. pylori infection. The supercritical anti-solvent fractionation (SAF) process of YE allowed the obtaining of two different fractions: yarrow’s precipitated fraction (YPF), enriched in most polar phenolic compounds (luteolin-7-O-glucoside, luteolin, and 3,5-dicaffeoylquinic acid), and yarrow’s separator fraction (YSF), enriched in monoterpenes and sesquiterpenes, mainly containing camphor, artemisia ketone, and borneol. YE was effective in reducing reactive oxygen species (ROS) production in human gastric AGS cells by 16% to 29%, depending on the H. pylori strain. YPF had the highest inhibitory activity (38–40%) for ROS production. YE modulated the inflammatory response in AGS gastric cells, decreasing IL-8 production by 53% to 64%. This IL-8 inhibition also showed a strain-dependent character. YPF and YSF exhibited similar behavior, reducing IL-8 production, suggesting that both phenolic compounds and essential oils could contribute to IL-8 inhibition. YSF showed the highest antibacterial activity against H. pylori (6.3–7.1 log CFU reduction, depending on the strain) and lower MIC (0.08 mg/mL). Results obtained have shown that YE and SAF fractions (YPF and YSF) were effective as antioxidant, anti-inflammatory, and antibacterial agents regardless of the H. pylori strain characteristics.

Comparative Studies on Essential Oil and Phenolic Content with In Vitro Antioxidant, Anticholinesterase, Antimicrobial Activities of Achillea biebersteinii Afan. and A. millefolium subsp. millefolium Afan. L. Growing in Eastern Turkey

The potential applications of Achillea species in various industries have encouraged the examination of their phytochemical components along with their biological potential. In the present study, phenolic contents and essential oil compositions together with the in vitro biological activities of the aerial parts from Achillea biebersteinii Afan. and Achillea millefolium subsp. millefolium Afan. collected from Turkey were evaluated. Different solvent extracts (n-hexane, chloroform, methanol, water) were prepared and their antimicrobial, anticholinesterase, and antioxidant activities were studied. The LC-MS/MS results revealed the presence of 16 different phenolic compounds, including chlorogenic acid, rutin, quercetin, and luteolin glycosides, in methanolic extracts. According to GC-FID and GC/MS results, the primary components of the oils were identified as 1,8-cineole (32.5%), piperitone (14.4%), and camphor (13.7%) in A. biebersteinii and 1,8-cineole (12.3%) and β-eudesmol (8.9%) in A. millefolium subsp. millefolium. The infusion and methanolic extracts of both species were found to be rich in their total phenolic content as well as their antioxidant and anticholinesterase activity. In contrast, the n-hexane and chloroform extracts of both species showed strong antimicrobial activity with MIC values ranging from 15 to 2000 μg/mL. Our findings suggest that the investigated Achillea species could be evaluated as potent natural agents, and further studies into the promising extracts are needed.