Influence of seasonal variation on Thymus longicaulis C. Presl chemical composition and its antioxidant and anti-inflammatory properties

Plant-derived and dietary phenolic cinnamic acid derivatives: Anti-inflammatory properties

Cinnamic acids are aromatic acids primarily found in plants and plant-derived food. Phenolic cinnamic acids, with one or more hydroxyl groups in the aromatic ring, often contribute to the biological activities attributed to these compounds. The presence of hydroxyl groups and a carboxyl group makes cinnamic acids very hydrophilic, preventing them from crossing biological membranes and exerting their biological activities. To alleviate this condition, a panel of synthetic modifications have been made leading to a diverse set of phenolic cinnamic structures. In this review, an overview of the natural phenolic cinnamic acid derivatives and their plant sources (more than 200) is described. The synthetic approaches to obtain the referred derivatives (more than 200) namely esters and amides are reviewed. Further, their anti-inflammatory activity (more than 70 compounds) is scrutinized. Finally, future directions will be indicated to translate the research on phenolic cinnamic derivatives into potentially effective anti-inflammatory drugs.

Linking Variability in Phytochemical Composition with Safety Profile of Thymus carnosus Boiss. Extracts: Effect of Major Compounds and Evaluation of Markers of Oxidative Stress and Cell Death

Natural products are generally considered safe for human consumption, but this classification is often based on ethnobotanical surveys or their use in traditional medicine over a long period of time. However, edaphoclimatic factors are known to produce different chemotypes, which may affect the safety profile and bioactivities, and are not commonly considered for plants exploited as crops worldwide. Thymus carnosus Boiss., a thyme species with various health-promoting effects, has potential pharmaceutical applications, but edaphoclimatic factors were found to significantly impact its phytochemical composition. Thus, we aimed to assess the safety profile of T. carnosus extracts obtained from plants harvested in two locations over three consecutive years and to establish an association with specific components, an essential study in the search for new sources of nutraceuticals. Thus, the antiproliferative effect of an aqueous decoction (AD), hydroethanolic (HE) extracts, and major extracts' components of T. carnosus was evaluated on intestinal (Caco-2) and hepatic (HepG2) cell models, revealing effects dependent on extract type, cell line, and tested compounds. Flavonoids induced different cytotoxic patterns, which could be attributed to molecular structural differences. Flow cytometry analysis showed apoptosis and necrosis induction, mediated by the modulation of intracellular reactive oxygen species and mitochondrial membrane potential, effects that were dependent on the cell line and phytochemical composition and on the synergism between extracts components, rather than on the activity of an isolated compound. While ursolic acid was the component with the strongest impact on the difference between extraction methods, flavonoids assumed a pivotal role in the response of different cell lines to the extracts. We report for the first time, for Thymus spp. extracts, that variations in the phytochemical composition clearly influence the cellular response, thus highlighting the need for extract standardization for medicinal applications.

LC-MS/MS and GC-MS profiling, antioxidant, enzyme inhibition, and antiproliferative activities of Thymus leucostomus H ausskn. & V elen. extracts

The chemical composition as well as antioxidant, antiproliferative, and enzyme inhibition activities of extracts from aerial parts of Thymus leucostomus H ausskn. & V elen. obtained with hexane, methanol, and water were evaluated. Results showed that the methanol extract had significantly (p < 0.05) the highest total phenolic content (TPC; 107.80 mg GAE/g) and total flavonoids content (TFC; 25.21 mg RE/g) followed by the aqueous extract (102.72 mg GAE/g and 20.88 mg RE/g, respectively). LC-MS/MS-guided profiling of the three extracts revealed that rosmarinic acid (34.8%), hesperetin (42.9%), and linoleic acid (18%) were the dominant compounds in the methanol, aqueous and hexane extracts, respectively. GC-MS analysis of the hexane extract showed that ɣ-sitosterol (29.9%) was the major constituent. The methanol extract displayed significantly (p < 0.05) the highest Cu++ , Fe+++ , and Mo(VI) ions scavenging and reducing properties while the aqueous extract exerted significantly (p < 0.05) the highest metal chelating power (42.51 mg EDTAE/g). Both the hexane and methanol extracts effectively inhibited the acetylcholinesterase enzyme (2.63 and 2.65 mg GALAE/g, respectively) while the former extract exerted significantly (p < 0.05) the highest butyrylcholinesterase (2.32 mg GALAE/g), tyrosinase (19.73 mg KAE/g), and amylase (1.16 mmol ACAE/g) inhibition capacity. The aqueous extract exhibited the best glucosidase inhibition property (0.49 mmol ACAE/g). The methanol and hexane extracts exerted a higher cytotoxic effect on HT-29 (IC50 : 8.12 µg/mL) and HeLa (IC50  = 8.08 µg/mL) cells, respectively. In conclusion, these results provide valuable insight into the potential use of T. leucostomus bioactive extracts in different pharmaceutical applications.

Antioxidant Potential of Spray- and Freeze-Dried Extract from Oregano Processing Wastes, Using an Optimized Ultrasound-Assisted Method

Origanum vulgare is recognized worldwide for its numerous applications, in the food industry and beyond. However, the extraction of its essential oils generates a significant amount of waste. The aim of this research was to achieve the valorization of solid waste from oregano hydro-distillation, by (i) optimizing the ultrasound extraction of antioxidants, (ii) evaluating the effect of spray and freeze drying on the extract's physicochemical properties, and (iii) characterizing the obtained powder by its antioxidant capacity. A central composite design of experiments was used to optimize the sample/solvent ratio, ethanol/water ratio, and extraction time. The extract was analyzed for its antioxidant potential by determining the percentage of DPPH inhibition, FRAP, and total phenolic content (TPC). The GAB model best fit the data for the moisture sorption isotherm of the resulting powder. The antioxidant activity of the powders was tested in a ground-beef food system. The TPC was maximized at times longer than 58 min, a sample/solvent ratio between 0.058 and 0.078, and a ratio of ethanol/water around 1. Neither drying method significantly affected the antioxidant properties of the extract, even though the resulting powders from each showed a different morphology (determined using SEM). Encapsulation with maltodextrin protected the spray-dried extract during a 6-month storage period. Powders from both drying methods equally retarded lipid oxidation, and were comparable to the synthetic antioxidant BHT. It is concluded that oregano processing waste is a potent source of antioxidants, and that its dried extract, via an ultrasound-assisted process, can potentially be used as a natural alternative to synthetic antioxidants.

Overcoming the Challenges of Phytochemicals in Triple Negative Breast Cancer Therapy: The Path Forward

Triple negative breast cancer (TNBC) is a very aggressive subtype of breast cancer that lacks estrogen, progesterone, and HER2 receptor expression. TNBC is thought to be produced by Wnt, Notch, TGF-beta, and VEGF pathway activation, which leads to cell invasion and metastasis. To address this, the use of phytochemicals as a therapeutic option for TNBC has been researched. Plants contain natural compounds known as phytochemicals. Curcumin, resveratrol, and EGCG are phytochemicals that have been found to inhibit the pathways that cause TNBC, but their limited bioavailability and lack of clinical evidence for their use as single therapies pose challenges to the use of these phytochemical therapies. More research is required to better understand the role of phytochemicals in TNBC therapy, or to advance the development of more effective delivery mechanisms for these phytochemicals to the site where they are required. This review will discuss the promise shown by phytochemicals as a treatment option for TNBC.

Flowering phenophases influence the antibacterial and anti-biofilm effects of Thymus vulgaris L. essential oil

BACKGROUND

Essential oils are becoming increasingly popular in medicinal applications because of their antimicrobial effect. Thymus vulgaris L. (Lamiaceae) is a well-known and widely cultivated medicinal plant, which is used as a remedy for cold, cough and gastrointestinal symptoms. Essential oil content of thyme is responsible for its antimicrobial activity, however, it has been reported that the chemical composition of essential oils influences its biological activity. In order to explore flowering phenophases influence on the chemical composition of thyme essential oil and its antibacterial and anti-biofilm activity, plant materials were collected at the beginning of flowering, in full bloom and at the end of flowering periods in 2019.

METHODS

Essential oils from fresh and dried plant materials were distilled and analyzed with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID). The antibacterial activity was performed by broth microdilution and thin layer chromatography-direct bioautography (TLC-DB) assays and the anti-biofilm effect by crystal violet assay, respectively. Scanning electron microscopy was applied to illustrate the cellular changes of bacterial cells after essential oil treatment.

RESULTS

Thymol (52.33-62.46%) was the main component in the thyme essential oils. Thyme oil distilled from fresh plant material and collected at the beginning of flowering period exerted the highest antibacterial and anti-biofilm activity against Haemophilus influenzae, H. parainfluenzae and Pseudomonas aeruginosa.

CONCLUSION

The different flowering periods of Thymus vulgaris influence the antibacterial and anti-biofilm activity of its essential oils, therefore, the collection time has to be taken into consideration and not only the full bloom, but the beginning of flowering period may provide biological active thyme essential oil.

Phytochemical Composition and Antioxidant, Anti-Acetylcholinesterase, and Anti-α-Glucosidase Activity of Thymus carnosus Extracts: A Three-Year Study on the Impact of Annual Variation and Geographic Location

Thymus carnosus Boiss. is a near-threatened species, and, as for many species, its potential for medicinal purposes may be lost if measures towards plant protection are not taken. A way of preserving these species is to increase knowledge about their medicinal properties and economic potential. Thus, with the objective of studying the potentiality of introducing T. carnosus as a crop, the stability of the phytochemical profile of T. carnosus was studied during a period of three years by comparing the phytochemical profile of extracts obtained from plants harvested in two different edaphoclimatic locations, as well as by comparing the respective bioactivities, namely, antioxidant, antidiabetic, antiaging, and neuroprotective activities. It was reported, for the first time, the effect of annual variation and geographic location in the phytochemical composition of aqueous decoction and hydroethanolic extracts of T. carnosus. In addition, the presence of two salvianolic acid B/E isomers in T. carnosus extracts is here described for the first time. Despite the variations in phytochemical composition, according to harvesting location or year, T. carnosus extracts maintain high antioxidant activity, assessed by their capacity to scavenge ABTS^•+, ^•OH , NO^•, O₂^•- radicals, as well as to prevent β-carotene bleaching. All extracts presented significant potential to inhibit acetylcholinesterase (AChE), tyrosinase, and α-glucosidase, denoting neuroprotective, anti-aging, and anti-diabetic potential. In conclusion, the vegetative stage and location of harvest are key factors to obtain the maximum potential of this species, namely, a phytochemical profile with health benefit bioactivities.

Trend of Antioxidant Activity and Total Phenolic Content in Wild Edible Plants as Part of the Environmental Quality Assessment of Some Areas in the Central Italy

Polyphenols are secondary metabolites of interest due to their potential application in various fields. This study is supposed to analyse the content of total polyphenols, total tannins, condensed tannins and antioxidant activity of ten wild plant species of nutritive interest to better understand their potential applications. Furthermore, the effect of heavy metals on the production of the investigated secondary metabolites was analysed. The different phenolic compounds were determined in methanol extracts obtained from edible plants collected during three sampling periods (June, September and November–December) in four areas of the Central Italy. Analyses were carried out by applying standard methodologies. In particular, total polyphenols were determined by the Folin–Ciocalteu method, total tannins by the polyvinylpolypyrrolidone (PVPP) reagent and condensed tannins by the 4-(dimethylamino)cinnamaldehyde (DMCA). Antioxidant activity was determined by assessing the scavenging capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The results showed a satisfactory content of phenolic compounds and antioxidant activity for all species analysed. Furthermore, the existence of a negative correlation between the presence of heavy metals and phenolic compounds was found. Results proved the potential use of these plants for balanced feeding of ruminants.

Modulation of Cell Death Pathways for Cellular Protection and Anti-Tumoral Activity: The Role of Thymus spp. Extracts and Their Bioactive Molecules

Natural products used for their health-promoting properties have accompanied the evolution of humanity. Nowadays, as an effort to scientifically validate the health-promoting effects described by traditional medicine, an ever-growing number of bioactivities are being described for natural products and the phytochemicals that constitute them. Among them, medicinal plants and more specifically the Thymus genus spp., arise as products already present in the diet and with high acceptance, that are a source of phytochemicals with high pharmacological value. Phenolic acids, flavonoid glycoside derivatives, and terpenoids from Thymus spp. have been described for their ability to modulate cell death and survival pathways, much-valued bioactivities in the pharmaceutical industry, that continually sought-after new formulations to prevent undesired cell death or to control cell proliferation. Among these, wound treatment, protection from endogenous/exogenous toxic molecules, or the induction of selective cell death, such as the search for new anti-tumoral agents, arise as main objectives. This review summarizes and discusses studies on Thymus spp., as well as on compounds present in their extracts, with regard to their health-promoting effects involving the modulation of cell death or survival signaling pathways. In addition, studies regarding the main bioactive molecules and their cellular molecular targets were also reviewed. Concerning cell survival and proliferation, Thymus spp. present themselves as an option for new formulations designed for wound healing and protection against chemicals-induced toxicity. However, Thymus spp. extracts and some of their compounds regulate cell death, presenting anti-tumoral activity. Therefore Thymus spp. is a rich source of compounds with nutraceutical and pharmaceutical value.

Rosmarinic Acid and Related Dietary Supplements: Potential Applications in the Prevention and Treatment of Cancer

Cancer constitutes a severe threat to human health and quality of life and is one of the most significant causes of morbidity and mortality worldwide. Natural dietary products have drawn substantial attention in cancer treatment and prevention due to their availability and absence of toxicity. Rosmarinic acid (RA) is known for its excellent antioxidant properties and is safe and effective in preventing and inhibiting tumors. This review summarizes recent publications on culture techniques, extraction processes, and anti-tumor applications of RA-enriched dietary supplements. We discuss techniques to improve RA bioavailability and provide a mechanistic discussion of RA regarding tumor prevention, treatment, and adjuvant therapy. RA exhibits anticancer activity by regulating oxidative stress, chronic inflammation, cell cycle, apoptosis, and metastasis. These data suggest that daily use of RA-enriched dietary supplements can contribute to tumor prevention and treatment. RA has the potential for application in anti-tumor drug development.

Phenolic compounds, antioxidant and antibacterial activities of extracts from aerial parts of Thymus zygis subsp. gracilis, Mentha suaveolens and Sideritis incana from Morocco

Thymus zygis subsp. gracilis , Mentha suaveolens and Sideritis incana (Lamiaceae family) are well recognized for their medicinal, pharmaceutical and aromatic properties. The present study aimed to investigate for the first time the polyphenolic composition, the antioxidant and antibacterial properties of the extracts obtained from the aerial parts of these species collected from the Ifrane region of Morocco. The polyphenolic compounds were determined using high-performance liquid chromatography coupled to photodiode array and electrospray ionization mass spectrometry (HPLC-PDA-ESI/MS). The antioxidant activity was investigated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, reducing power and ferrous ion chelating assays. The antibacterial activity was evaluated against three Gram-negative bacteria ( Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium ) and three Gram-positive bacteria ( Staphylococcus aureus, Enterococcus faecalis and Listeria monocytogenes ). A total of thirty-three, sixteen and thirteen polyphenolic compounds were positively identified and characterized in T. zygis subsp. gracilis , M. suaveolens and S. incana extracts, respectively. Among the extracts, M. suaveolens exhibited the highest antioxidant activity, followed by S. incana and T. zygis subsp. gracilis in both DPPH and reducing power assays; all extracts showed the lowest activity in the chelating assay. In addition, all extracts demonstrated a bactericidal effect against Gram-positive bacteria and bacteriostatic effect against Gram-negative bacteria. Therefore, the aerial parts of Moroccan T. zygis subsp. gracilis , M. suaveolens and S. incana might be considered as a valuable source of natural antioxidant and antibacterial agents with potential application in food and pharmaceutical industries.

SIMULTANEOUS IDENTIFICATION, QUANTIFICATION, AND ANALYSIS OF MAIN COMPONENTS OF “HAIRY” ROOT EXTRACTS OF Artemisia annua AND Artemisia tilesii PLANTS

Aim. The profiles of polyphenolic phytochemicals in extracts of “hairy” roots of Artemisia tilesii Ledeb. and Artemisia annua L. were studied. Analytical separation and quantification of main components in extracts were evaluated. Methods. “hairy” roots were grown in vitro on Murashige and Skoog medium. High-performance chromatography coupled with different types of detection (photo diode array detection (DAD) and electrospray ionization with ultra-high resolution Qq-Time-of-Flight mass spectrometry) was used to identify and quantify the main biologically active components in ethanol extracts of “hairy” roots. Results. The amount of flavonoids was 94.71–144.33 mg RE/g DW and 33.52–78.00 mg RE/g DW in “hairy” roots of A. annua and A. tilesii, respectively. In most samples of “hairy” roots, the amount of flavonoids was higher than the content in the control plant roots. The presence of Apigenin (0.168 ± 0.003 mg/L and 0.178 ± 0.006 mg/L), Quercetin (0.282 ± 0.005 mg/L and 0.174 ± 0.005 mg/L) in the extracts of A. annua and A. tilesii was shown by reverse-phase HPLC-DAD method. Chlorogenic acid, Kaempferol, and other flavonoids were detected. Conclusions. The developed HPLC-DAD method demonstrated the high percentage of recovery, low limit of detection and quantification (9,11 ng/ml ≤ LOQ ≤16,51 ng/ml), accuracy and correctness. Thus, the method is suitable for the simultaneous quantification of phenolic acids and flavonoids in various plant extracts with short time and high efficiency.

Salvia officinalis and Lippia triphylla: Chemical characterization and evaluation of antidepressant-like activity

Salvia officinalis (Lamiaceae) and Lippia triphylla (Verbenaceae) are two plants known for their therapeutic effects in conventional medicine for the treatment of a wide extent of diseases, including the ones on the central nervous system. In the present study, the impact of aqueous extract from the leaves of these two herbs for the treatment of depression was examined. The phytochemical profile highlighted the presence of eighteen and ten polyphenolic compounds in Salvia officinalis and Lippia triphylla, respectively. The antidepressant effects of such extracts were assessed using two tests: the forced swimming test (FST) and tail suspension test (TST) in swiss albino mice. Five mice were partitioned into each group: control (distilled water), standard (Imipramine hydrochloride, 25 mg/kg) and three test ones treated with increased doses of aqueous extracts (250-500-1000 mg/kg), orally administered for two weeks. The acute treatment of the mice with aqueous extracts of Salvia officinalis and Lippia triphylla reduced significantly the time of immobility in the forced swimming test (p < 0.001) as compared to control group, and also decreased significantly the time of immobility of mice in the tail suspension test (p < 0.001). The findings attained in this work show how both plants possess potential anti-depressant-like effects; however, the translation from the results presented in this work to a potential use as therapeutic agents would require the acquisition of a stronger scientific evidence.

Seasonal Variations of Rosmarinic Acid and Its Glucoside and Expression of Genes Related to Their Biosynthesis in Two Medicinal and Aromatic Species of Salvia subg. Perovskia

Simple Summary

Here, we studied two closely related medicinal and aromatic plants from Asia, called Russian sage or from their previously used Latin name–Perovskia. These plants contain various specialized metabolites called phenylpropanoids that contribute to their medicinal uses. In our experiments, several different specialized phytochemicals were traced down in the roots and leaves with the major metabolite called rosmarinic acid, known for health beneficial properties. In order to check if the composition of these plants is regulated by specific genes encoding proteins that assemble these phytochemicals, we analyzed their expression during the growth season (spring, summer and fall). Despite being the closest kin, the two species of Russian sage displayed different seasonal changes in the composition of bioactive metabolites and the activity of genes responsible for their production. The genes’ activity was correlated with rosmarinic acid content in the roots but not in the green parts of the plants. Two genes pointed out were linked to the regulation of rosmarinic acid biosynthesis, called RAS (for Rosmarinic Acid-Synthase) and a newly reported version of an oxidizing enzyme called Cyp98A14. These discoveries broaden our understanding of relationships between the genes’ activity and production of bioactive constituents in herbs such as the two studied species of Russian sages.

Abstract

Salvia abrotanoides Kar. and Salvia yangii B.T. Drew are medicinal and aromatic plants belonging to the subgenus Perovskia and used as herbal medicines in Asia. Derivatives of caffeic acid, mainly rosmarinic acid (RA), are the major phenolic compounds identified in these plants. Understanding the factors and molecular mechanisms regulating the accumulation of pharmacologically and ecologically relevant phenolic metabolites is essential for future biotechnological and medical applications. Up to date, no studies of phenylpropanoid biosynthetic pathway at the transcriptional level has been performed in the Perovskia subgenus. Using a combined qRT-PCR transcriptional activity analysis with LC-MS based metabolic profiling of roots and leaves at the beginning, in the middle and at the end of vegetation season, we have identified the following gene candidates with properties correlating to phenolic acid biosynthesis in S. abrotanoides and S. yangii: PAL, C4H, 4CL, TAT, HPPR, RAS1, RAS2 and Cyp98A14. A comparison of phenolic acid profiles with gene transcript levels revealed the transcriptional regulation of RA biosynthesis in the roots but not the leaves of the studied species. Additionally, RAS1 and Cyp98A14 were identified as rate-limiting steps regulating phenylpropanoid biosynthesis on a transcription level. In the future, this will facilitate the gene-based metabolic enhancement of phenolic compounds production in these promising medicinal herbs.

Molecular Action of Polyphenols in Leukaemia and Their Therapeutic Potential

Leukaemia is a malignant disease of the blood. Current treatments for leukaemia are associated with serious side-effects. Plant-derived polyphenols have been identified as potent anti-cancer agents and have been shown to work synergistically with standard chemotherapy agents in leukaemia cell lines. Polyphenols have multiple mechanisms of action and have been reported to decrease cell proliferation, arrest cell cycle and induce apoptosis via the activation of caspase (3, 8 and 9); the loss of mitochondrial membrane potential and the release of cytochrome c. Polyphenols have been shown to suppress activation of transcription factors, including NF-kB and STAT3. Furthermore, polyphenols have pro-oxidant properties, with increasing evidence that polyphenols inhibit the antioxidant activity of glutathione, causing oxidative DNA damage. Polyphenols also induce autophagy-driven cancer cell death and regulate multidrug resistance proteins, and thus may be able to reverse resistance to chemotherapy agents. This review examines the molecular mechanism of action of polyphenols and discusses their potential therapeutic targets. Here, we discuss the pharmacological properties of polyphenols, including their anti-inflammatory, antioxidant, anti-proliferative, and anti-tumour activities, and suggest that polyphenols are potent natural agents that can be useful therapeutically; and discuss why data on bioavailability, toxicity and metabolism are essential to evaluate their clinical use.

Rosmarinic acid protects against ulcerative colitis by regulating macrophage polarization depending on heme oxygenase-1 in mice

Ulcerative colitis (UC) is an unknown-cause inflammatory disease of colorectum. At present, there are no specific therapeutic drugs. We found that rosmarinic acid (RA) can significantly improve UC and further explored the relevant cellular and molecular mechanisms. Firstly, using F4/80 as marker for mouse macrophages, we found there were large numbers of macrophages infiltrating into colonic tissue of dextran sulfate sodium (DSS)-induced mice UC model. Meanwhile, RA markedly improved weight loss, diarrhea, hematochezia and colonic inflammation in mice with DSS treatment. Further, RA changed macrophage polarization in mouse colon, showing that classical activation (M1) phenotype decreased, alternative activation (M2) phenotype increased, and M1/M2 ratio reversed by Real-time PCR. In vitro, we cultured the peripheral blood macrophages (PBM) and found that RA inhibited PBM M1 polarization and favored M2 polarization directly. Heme oxygenase-1 (HO-1) mediated the anti-inflammatory effect of RA. RA induced HO-1 expression in PBM, and the HO-1 inhibitor, zinc protoporphyrin, blunted the inhibitory effect of RA on lipopolysaccharide (LPS)-induced nuclear factor-kappa B (NF-κB) translocation and M1 polarization. In addition, blocking NF-κB signal has no effect on the role of RA. In conclusion, RA protects against UC by regulating macrophage polarization depending on HO-1. These data suggest that reversing macrophage polarization can be used as a strategy for UC treatment and RA is an effective drug to cure UC by regulating macrophage polarization.

Health-Promoting Effects of Thymus Phenolic-Rich Extracts: Antioxidant, Anti-Inflammatory and Antitumoral Properties

Thymus genus comprises numerous species that are particularly abundant in the West Mediterranean region. A growing body of evidence suggests that many of these species are a rich source of bioactive compounds, including phenolic compounds such as rosmarinic acid, salvianolic acids and luteolin glycosides, able to render them potential applications in a range of industrial fields. This review collects the most relevant studies focused on the antioxidant, anti-inflammatory and anti-cancer of phenolic-rich extracts from Thymus plants, highlighting correlations made by the authors with respect to the main phenolic players in such activities.

‘Hairy’ root extracts as source for ‘green’ synthesis of silver nanoparticles and medical applications

The research was focused on the synthesis of silver nanoparticles (AgNPs) using extracts from the “hairy” root cultures of Artemisia tilesii Ledeb. and Artemisia annua L. The effect of operational parameters such as type of solvent, temperature of extraction, flavonoids concentration, and reducing power of the wormwood “hairy” root extracts on the particle size and yield of the resultant nanoparticles is reported for the first time. From the studied solvents, a water–ethanol mixture with a concentration of 70 vol% was found to be the best for the extraction of flavonoids from all “hairy” root cultures. The total flavonoid contents in A. annua and A. tilesii “hairy” root extracts were up to 80.0 ± 0.9 and 108 ± 4.4 mg RuE per g DW, respectively. Identification of flavonoids was confirmed by UPLC-ESI-UHR-Qq-TOF-MS analysis. Luteolin-7-β-d-glucopyranosid, isorhamnetin 3-O-glucoside, baicalein-7-O-glucuronide, apigenin-7-O-glucoside, quercetin, sitosterol, caffeoylquinic, galic, chlorogenic and caffeic acids were founded in the extracts. These extracts demonstrated the high reducing activities. Spherical, oval and triangular nanoparticles with effective sizes of 5–100 nm were observed. The TEM data revealed great differences in the shapes of NPs, obtained from the extracts from different root clones. The clustered and irregular NPs were found in the case of using ethanol extracts, mostly aggregated and having the size of 10–50 nm. The sizes of AgNPs decreased to 10–30 nm in the case of using aqueous extracts obtained at 80 °C. Biosynthesized AgNPs showed surface plasmon resonance in the range of 400–450 nm. The antimicrobial activity of the as-produced AgNPs was studied by disc diffusion method on Gram-positive (Staphylococcus aureus ATCC 25923 (F-49)), Gram-negative (Pseudomonas aeruginosa ATCC 27853 (F-51), Escherichia coli ATCC 25922 (F-50)) and Candida albicans ATCC 88-653 strains. It was found that the nanoparticles in some cases possessed the greater ability to inhibit microorganism growth compared to 1 mM AgNO₃ solution. The colloidal solutions of the obtained AgNPs were stable in the dark for 12 months at room temperature. Thus, the A. annua and A. tilesii “hairy” root extracts can be used for obtaining of bioactive AgNPs.

The research was focused on the synthesis of silver nanoparticles (AgNPs) using extracts from the “hairy” root cultures of Artemisia tilesii Ledeb. and Artemisia annua L.

Traditional Uses, Chemical Constituents and Biological Activities of Plants from the Genus Thymus

The genus Thymus (Lamiaceae) comprises about 214 species throughout the world, mainly found in North Africa, Europe, and temperate Asia zone. They are traditionally used as food additives and folk medicines. This review comprehensively summarizes information about traditional uses, chemical constituents, and biological activities of this genus and provides recommendations for future investigations. All information was gathered from scientific databases including Google Scholar, Sci-Finder, Web of Science, ScienceDirect, and CNKI. Volatile oils are the most concerned constituents of this genus. Flavonoids, phenylpropanoids, tannins, organic acids, terpenoids, and phytosterols were also summarized. This genus plants possessed a variety of activities including antimicrobial, antioxidant, anti-inflammatory, cytotoxic, analgesic, and antidiabetic. In brief, this review will be helpful to provide valuable data for explorations and create more interests towards Thymus genus in the future.

Phytochemical Properties of Satureja kitaibelii, Potential Natural Antioxidants: a New Insight

Satureja kitaibelii Wierzb. ex Heuff. has a great importance in Serbian ethnopharmacology/herbal traditional medicine, as well as a flavoring food additive. Ethanol extract of aerial parts of Satureja kitaibelii analyzed by liquid chromatography-mass spectrometry revealed the presence of 18 compounds among which the most abundant were phenolic acids, flavonoids, jasmonic acid derivatives and rosmanol. The extracts were rich in total phenolics and flavonoid contents, while rosmarinic acid was the dominant compound (18.30-29.52 mg/g). As assessments of antioxidant properties of natural extracts are important because of their growing use in medicine and food industry, antioxidant activity of ethanol extracts of Satureja kitaibelii was analyzed by several assays. The half maximal scavenging capacity (SC₅₀) of 2,2'-diphenyl-1-picrylhydrazyl ranging from 71.20 to 125.65 μg/mL, the total antioxidant capacity from 272.37 to 714.12 mg ascorbic acid/g, and ferric ion reducing antioxidant power ranging from 0.74 to 1.94 μmol Fe/mg, clearly imply a significant antioxidant potential of Satureja kitaibelii. The extracts inhibit growth of Micrococcus luteus and Pseudomonas aeruginosa with inhibition zones 20-30 and 16-26 mm, respectively. Antioxidant and antibacterial activity of compounds identified in extracts suggest a great potential for Satureja kitaibelii application as valuable food ingredient.

Bioactivities of Flavonoids from Lopezia racemosa

Lopezia racemosa Cav. (Onagraceae) has been used in Mexican traditional medicine to alleviate stomachache, biliary colic, urine retention, stomach cancer, and skin, dental, buccal, and urinary infections. The objective of this study was to determine the bioactivities of specific parts of the plant to scientifically confirm its traditional use. Aerial parts and flowers were macerated and subsequently extracted with hexane, chloroform, and methanol. This study was focused on the analysis of polar components, and thus the methanolic fractions were selected for further investigations. These fractions were evaluated for their antimicrobial activity using a panel of bacterial Gram-positive and -negative strains, as well as fungal strains, including filamentous fungi and yeasts. In addition, the cytotoxic activity of the extract was assessed by MTT using the human-derived monocytic THP-1 and the normal human fibroblast cell lines. Various fractions showed antimicrobial activity against various pathogens, although the most relevant were against Pseudomonas aeruginosa and Trichophyton mentagrophytes. No inhibition of yeasts was recorded. Only four fractions showed cytotoxic effects when the human-derived THP-1 and fibroblast cells were assessed. The four flavonoids isolated from the extract were luteolin, luteolin-6-C-hexoside, luteolin-8-C-hexoside, and hyperoside. The biological activities presented in this study validate some traditional uses of the plant.

A Comparative Study of Essential Oil Constituents and Phenolic Compounds of Arabian Lilac (Vitex Trifolia var. Purpurea): An Evidence of Season Effects

To evaluate the fluctuation of secondary metabolites in Arabian lilac during a year, aerial parts of the plant were harvested in the middle of each month. The essential oils content from fresh and dried plant materials was analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometer (GC-MS), individually. Phytochemical contents, along with antiradical scavenging potential of the related methanol extracts were separately assessed. The spring and autumn samples (fresh and dried) yielded more essential oil than the other samples. Forty-one compounds were identified totally in the oils and the major constituents characterized were β-caryophyllene, sabinene, and caryophyllene oxide. The extracts obtained from winter and summer plants possessed the highest total phenolics. The maximum amount of total flavonoid content was measured in winter (December and January), whereas the minimum one was observed in spring (March). The summer and winter samples showed the highest and lowest content of flavones and flavanols, respectively, whereas the anthocyanin content was higher in winter than in summer. Moreover, antiradical activity of the extracts in summer and winter samples was higher than in other seasons. Overall, this study can provide useful information regarding the best harvest period of Arabian lilac to yield the desired compounds for application in phytopharmaceutical and food industries.

In Vitro Study of Multi-Therapeutic Properties of Thymus bovei Benth. Essential Oil and Its Main Component for Promoting Their Use in Clinical Practice

Thymus bovei Benth. (TB) is an important plant in the traditional medicine of the Mediterranean region. This study investigates the health-promoting properties of TB essential oil (TB-EO) for its possible use in clinical practice with regards to its cytotoxic, anti-herpes simplex virus type 2 (HSV-2), and antihypertensive (through inhibition of human angiotensin-converting enzyme; ACE) properties. The phytochemical profile of EO (99.9%) was analyzed by Gas Chromatography with Flame-Ionization Detection (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS). In this study, all biological methods were performed at the level of in vitro studies. The results showed that TB-EO exerted remarked cytotoxic properties against human cervical carcinoma cells, colon cancer cells, and lung adenocarcinoma cells with the half-maximal inhibitory concentration (IC₅₀) values of 7.22, 9.30, and 8.62 µg/mL, respectively, in comparison with that of standard anticancer drug cisplatin with IC₅₀ values of 4.24, 5.21, and 5.43 µg/mL, respectively. Fascinatingly, TB-EO showed very weak cytotoxicity on the healthy human fetal lung fibroblast cells with an IC₅₀ value of 118.34 µg/mL compared with that of cisplatin (IC₅₀ = 10.08 µg/mL). TB-EO, its main component geraniol, TB-EO combined with acyclovir (ACV) along with standard ACV, have displayed pronounced inhibitory properties against the replication of HSV-2 with the half-maximal effective concentration (EC₅₀) values of 2.13, 1.92, 0.81 and 1.94 µg/mL, respectively, with corresponding selectivity indices (SI) 98.59, 109.38, 259.26 and 108.25, respectively. TB-EO and geraniol at a concentration of 15 µg/mL showed prominent inhibitory activities against ACE with % of inhibition 95.4% and 92.2%, respectively, compared with that of standard inhibitor captopril (99.8%; 15 µg/mL). Molecular docking studies were performed to unveil the mechanism of action of geraniol as well as structural parameters necessary for anti-HSV-2 activity (through the inhibition of HSV-2 protease) and ACE inhibition. This is the first report on the chemical composition of Egyptian TB-EO along with the above-mentioned biological activities. Our results may be considered as novel findings in the course of a search for new and active anticancer, anti-HSV-2 and antihypertensive agents, and expand the medicinal value of this plant and its phytochemicals in clinical practice.

Naturally complex: Perspectives and challenges associated with Botanical Dietary Supplement Safety assessment

Due to the extensive use of botanical dietary supplements by consumers in the United States, there is a need for appropriate research and data to support safety assessments. Complexity and variability, both natural and introduced, of botanical dietary supplements make research on these products difficult. Botanical dietary supplements are regulated by the Food and Drug Administration (FDA) under the Federal Food, Drug, and Cosmetic Act (FD&C Act), as amended by the 1994 Dietary Supplement Health and Education Act (DSHEA). They are regulated as a category of food, which differs from the regulation of pharmaceutical products. Both manufacturers and the FDA are faced with the challenge of determining the best approaches for evaluating and monitoring the safety of botanical products. High quality botanicals research requires accurate identification and characterization of the material being studied. Inconsistent results in efficacy studies of botanical dietary supplements have led to efforts to improve the rigor and reproducibility of research in the field. Addressing the challenges associated with botanical dietary supplement safety is a global effort requiring coordination between numerous stakeholders, including researchers, suppliers, manufacturers, and regulators, all of whom play a role in ensuring that high quality products are available on the market.

Seasonal variation in Hibiscus sabdariffa (Roselle) calyx phytochemical profile, soluble solids and α-glucosidase inhibition

Seasonal variations in crops can alter the profile and amount of constituent compounds and consequentially any biological activity. Differences in phytochemical profile, total phenolic content and inhibitory activity on α-glucosidase (maltase) of Hibiscus sabdariffa calyces grown in South Western Nigeria were determined over wet and dry seasons. The phenolic profile, organic acids and sugars were analysed using HPLC, while inhibition of rat intestinal maltase was measured enzymically. There was a significant increase (1.4-fold; p ≤ 0.05) in total anthocyanin content in the dry compared to wet planting seasons, and maltase inhibition from the dry season was slightly more potent (1.15-fold, p ≤ 0.05). Fructose (1.8-fold), glucose (1.8-fold) and malic acid (3.7-fold) were significantly higher (p ≤ 0.05) but citric acid was lower (62-fold, p ≤ 0.008) in the dry season. Environmental conditions provoke metabolic responses in Hibiscus sabdariffa affecting constituent phytochemicals and nutritional value.

Essential oils (EOs), pressurized liquid extracts (PLE) and carbon dioxide supercritical fluid extracts (SFE-CO2) from Algerian Thymus munbyanus as valuable sources of antioxidants to be used on an industrial level

The aim of this study was to demonstrate the potential of extracts from Algerian Thymus munbyanus as a valuable source of antioxidants for use on an industrial level. To this end, a study was conducted on the composition and antioxidant activities of essential oils (EOs), pressurized liquid extracts (PLE) and supercritical fluid extracts (SFE-CO₂) obtained from Thymus munbyanus subsp. coloratus (TMC) and subsp. munbyanus (TMM). EOs and SFE-CO₂ extracts were analysed by GC-FID and GC×GC-TOFMS revealing significant differences. A successive extraction of the solid SFE-CO₂ residue by PLE extraction with solvents of increasing polarity such as acetone, ethanol and water, was carried out. The extracts were evaluated for total phenolic content by Folin-Ciocalteu assay, while the antioxidant power was assessed by DPPH, FRAP, and ORAC assays. SFE-CO₂ extracts were also analysed for their tocopherol content. The antioxidant activity of PLE extracts was found to be higher than that of SFE-CO₂ extracts, and this increased with solvent polarity (water > ethanol > acetone). Overall, these results support the use of T. munbyanus as a valuable source of substances to be used on an industrial level as preservative agents.

Cretan tea (Origanum dictamnus L.) as a functional beverage: an investigation on antiglycative and carbonyl trapping activities

Chemical characterization of dittany infusion and its inhibitory effects on AGEs formation at different stages of the glycation reaction were investigated.

Characterization of metabolite profiles from the leaves of green perilla ( Perilla frutescens ) by ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry and screening for their antioxidant properties

The objective of this research was to access the determination of metabolite profiles and antioxidant properties in the leaves of green perilla (Perilla frutescens), where these are considered functional and nutraceutical substances in Korea. A total of 25 compositions were confirmed as six phenolic acids, two triterpenoids, eight flavonoids, seven fatty acids, and two glucosides using an ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) technique from the methanol extract of this species. The individual and total compositions exhibited significant differences, especially rosmarinic acid (10), and linolenic acids (22 and 23) were detected as the predominant metabolites. Interestingly, rosmarinic acid (10) was observed to have considerable differences with various concentrations in three samples (Doryong, 6.38 μg/g; Sinseong, 317.60 μg/g; Bongmyeong, 903.53 μg/g) by UPLC analysis at 330 nm. The scavenging properties against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals also showed potent effects with remarkable differences at a concentration of 100 μg/mL, and their abilities were as follows: Sinseong (DPPH, 86%; ABTS, 90%) > Bongmyeong (71% and 84%, respectively) > Doryong (63% and 73%, respectively). Our results suggest that the antioxidant activities of green perilla leaves are correlated with metabolite contents, especially the five major compositions 10 and 22–25. Moreover, this study may be useful in evaluating the relationship between metabolite composition and antioxidant activity.

Synthesis of Bioactive Chlorogenic Acid-Silica Hybrid Materials via the Sol-Gel Route and Evaluation of Their Biocompatibility

Natural phenol compounds are gaining a great deal of attention because of their potential use as prophylactic and therapeutic agents in many diseases, as well as in applied science for their preventing role in oxidation deterioration. With the aim to synthetize new phenol-based materials, the sol-gel method was used to embed different content of the phenolic antioxidant chlorogenic acid (CGA) within silica matrices to obtain organic-inorganic hybrid materials. Fourier transform infrared (FTIR) measurements were used to characterize the prepared materials. The new materials were screened for their bioactivity and antioxidant potential. To this latter purpose, direct DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) methods were applied: radical scavenging capability appeared strongly dependent on the phenol amount in investigated hybrids, and became pronounced, mainly toward the ABTS radical cation, when materials with CGA content equal to 15 wt% and 20 wt% were analyzed. The in vitro biocompatibility of the synthetized materials was estimated by using the MTT assay towards fibroblast NIH 3T3 cells, human keratinocyte HaCaT cells, and the neuroblastoma SH-SY5Y cell line. As cell viability and morphology of tested cell lines seemed to be unaffected by new materials, the attenuated total reflectance (ATR)-FTIR method was applied to deeply measure the effects of the hybrids in the three different cell lines.

Screening and identification of Caulis Sinomenii bioactive ingredients with dual-target NF-κB inhibition and β2- AR agonizing activities

Caulis Sinomenii (CS) is a valuable traditional medicine in China. Its extract can act as an anti-inflammatory agent and a vascular smooth muscle relaxant. However, the underlying mechanisms remain unknown. In this study, we developed a simple dual-target method based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry combined with a dual-target bioactive screening assay for anti-inflammatory and antispasmodic activities to characterize the chemical structure of various bioactive compounds of CS rapidly. Seven potential NF-κB inhibitors were identified, including laudanosoline-1-O-xylopyranose, 6-O-methyl-laudanosoline-1-O-glucopyranoside, menisperine, sinomenine, laurifoline, magnoflorine and norsinoacutin. Furthermore, IL-6 and IL-8 assays confirmed the anti-inflammatory effects of these potential NF-κB inhibitors, in which laudanosoline-1-O-d-xylopyranose and menisperine were revealed as novel NF-κB inhibitors. Among the seven identified alkaloids, three potential β₂ -adrenergic receptor agonists, including sinomenine, magnoflorine and laurifoline, were characterized using a luciferase reporter system to measure for the activity of β₂ -adrenergic receptor agonists. Finally, sinomenine, magnoflorine and laurifoline were identified not only as potential NF-κB inhibitors but also as potential β₂ -adrenegic receptor agonists, which is the first time this has been reported. Molecular dynamic simulation and docking results suggest that the three dual-bioactive constituents could not only inhibit Pseudomonas aeruginosa PAK strain-induced inflammatory responses via a negative regulation of the Braf protein that participates in MAPK signaling pathway but also activate the β₂ -adrenegic receptor. These results suggest that CS extract has dual signaling activities with potential clinical application as a novel drug for asthma.

Antioxidant Properties of Phenolic Compounds in Renewable Parts of Crataegus pinnatifida inferred from Seasonal Variations

In this study, the effect of seasonal variations on Crataegus pinnatifida, changes in antioxidant activity and active components in C. pinnatifida leaves, roots, twigs, and fruits from May to October were investigated. Through correlation analysis of climatic factors and 7 phenolic compounds yield, the phenolic compounds content was positively correlated with temperatures and daytime. The correlation coefficient of temperatures and daytime were 0.912 and 0.829, respectively. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging and reducing power tests were employed to evaluate the antioxidant activity of the C. pinnatifida. C. pinnatifida leaves exhibited significant advantages in terms of higher phenolic contents and excellent antioxidant activities. Principal component analysis (PCA) revealed that 2 main PC characterize the C. pinnatifida phenolic composition (82.1% of all variance). C. pinnatifida leaves in September possessed remarkable antioxidant activity. The results elucidate that C. pinnatifida leaves, as renewable parts, are suitable for application as antioxidant ingredients.

Influence of harvest season on chemical composition and bioactivity of wild rue plant hydroalcoholic extracts

The rue (Ruta graveolens) copiousness in rural areas of the Campania Region based a thorough chemical and biological investigation aimed at exploring the seasonal variability of phenol constituents in rue leaves and its influence on their antioxidant, cytotoxic and anti-inflammatory capabilities. To this purpose, hydroalcoholic extracts were prepared from plant samples seasonally collected. LC-ESI-MS/MS techniques were employed to analyze qualitatively and quantitatively the seasonal rue phenol content, whereas different chemical antioxidant assays (by DPPH, ABTS, Fe(3+) RP, ORAC, and FCR methods) and XTT redox metabolic activity assay were performed to screen the seasonal phenol complex-related antioxidant and cytotoxic power. The ability of the rue leaf extracts to counteract cyclooxygenase-2 (COX-2) expression was also evaluated. Data obtained highlighted that the adopted extraction procedure markedly pauperized the furanocoumarin content in all the prepared rue extracts. Flavonol glycosides, along with the flavone acacetin and two sinapic acid derivatives were the main constituents of the spring harvest-derived extract, which exerted the highest antioxidant capability in cell-free systems and was capable to inhibit COX-2 synthesis by 44% comparably to dexamethasone, used as positive control. Data provide new insights for developing a proper management of rue plants for new safe industrial purposes in herbal medicine field.

The relevance of pharmacognosy in pharmacological research on herbal medicinal products

As all medicines, herbal medicinal products are expected to be safe, effective, and of appropriate quality. However, regulations on herbal medicinal products vary from country to country, and herbal preparations do occur not only in the form of medicinal products but also as less strictly regulated product groups like dietary supplements. Therefore, it is not always easy for the consumers to discriminate high-quality products from low-quality products. On the other hand, herbal medicines have many special features that distinguish them from conventional medicinal products. Plants are complex multicomponent mixtures; in addition, their phytochemical composition is not constant because of inherent variability and a plethora of external influences. Therefore, the production process of an herbal medicinal product needs to be strictly monitored. First of all, the starting materials need to be correctly authenticated and free of adulterants and contaminants. During plant growth, many factors like harvest season and time, developmental stage, temperature, and humidity have a strong impact on plant metabolite production. Also, postharvest processing steps like drying and storage can significantly alter the phytochemical composition of herbal material. As the production of many phytopharmaceuticals includes an extraction step, the extraction solvent and conditions need to be optimized in order to enrich the bioactive constituents in the extract. The quality of finished preparations needs to be determined either on the basis of marker constituents or on the basis of analytical fingerprints. Thus, all production stages should be accompanied by appropriate quality assessment measures. Depending on the particular task, different methods need to be applied, ranging from macroscopic, microscopic, and DNA-based authentication methods to spectroscopic methods like vibrational spectroscopy and chromatographic and hyphenated methods like HPLC, GC-MS and LC-MS. Also, when performing pharmacological and toxicological studies, many features inherent in herbal medicinal products need to be considered in order to guarantee valid results: concerning in vitro studies, difficulties are often related to lacking knowledge of ADME characteristics of the bioactive constituents, nuisance compounds producing false positive and false negative results, and solubility problems. In in vivo animal studies, the route of administration is a very important issue. Clinical trials on herbal medicinal products in humans very often suffer from a poor reporting quality. This often hampers or precludes the pooling of clinical data for systematic reviews. In order to overcome this problem, appropriate documentation standards for clinical trials on herbal medicinal products have been defined in an extension of the CONSORT checklist. This article is part of a Special Issue entitled "Botanicals for Epilepsy".

Inhibitory effects of wild dietary plants on lipid peroxidation and on the proliferation of human cancer cells

Thirteen hydroalcoholic extracts of edible plants from Southern Italy were evaluated for their in vitro antioxidant and antiproliferative activity on three human cancer cell lines: breast cancer MCF-7, hepatic cancer HepG2 and colorectal cancer LoVo. After 48 h of incubation the most antiproliferative plant extract was rosemary (Rosmarinus officinalis L.) on LoVo cell line with IC50 of 16.60 µg/ml. Oregano (Origanum vulgare L. subsp. viridulum) showed a selective antiproliferative activity on hepatic cancer with IC50 of 32.59 µg/ml. All the extracts, with the exception of Diplotaxis tenuifolia (L.) DC., exerted antioxidant properties, the most active plants being dewberry (Rubus caesius L.) and "laprista" (Rumex conglomerates Murray) with IC50 of 4.91 and 5.53 µg/ml, respectively. Rumex conglomeratus contained the highest amount of flavonoids (15.5 mg/g) followed by Portulaca oleracea L. (11.8 mg/g). Rosmarinus officinalis contained the highest number of terpenes. Among them ketoursene (14.7%) and aristolone (11.3%) were found to be the major constituents. P. oleracea and Raphanus raphanistrum L. subsp. landra contained the highest number of sterols.

Antioxidant and Anticholinesterase Potential of Six Thymus Species

The present study aimed to evaluate antioxidant and acetylcholinesterase (AChE) inhibitory activities of the ethanolic extracts of six selected Thymus species growing in Croatia (T. longicaulis, T. praecox subsp. polytrichus, T. pulegioides, T. serpyllum subsp. serpyllum, T. striatus, and T. vulgaris). Antioxidant effectiveness was assessed using six different assays, in comparison with rosmarinic acid, luteolin, and reference antioxidants. All tested Thymus extracts possessed DPPH (IC₅₀ = 3–6 μg/mL) and nitric oxide (IC₅₀ = 70–177 μg/mL) free radical scavenging activities, strong reducing properties (IC₅₀ = 11–15 μg/mL), ferrous ion chelating activity (IC₅₀ = 126–389 μg/mL), ability to inhibit lipid peroxidation (IC₅₀ = 34–80 μg/mL), and high total antioxidant capacities (238–294 mg AAE/g). AChE inhibitory activity was examined using Ellman's colorimetric method and all tested extracts showed anti-AChE activity in a dose dependent manner. The values of 10–28%, 23–39%, and 64–86% were obtained for tested concentrations of 0.25, 0.5, and 1 mg/mL, respectively. Additionally, the contents of total hydroxycinnamic derivatives, flavonoids, and tannins in dried plant samples were determined spectrophotometrically. Our results highlighted Thymus species as a rich source of natural antioxidants and AChE inhibitors that could be useful in preventing and treating Alzheimer's disease and other neurodegenerative disorders.