Identification and quantification of phenolic and volatile constituents in five different Anatolian thyme species using LC–MS/MS and GC-MS, with biological activities

Liquid chromatography-tandem mass spectrometry profile and antioxidant, antimicrobial, antiproliferative, and enzyme activities of Thymus pectinatus and Thymus convolutus: in vitro and in silico approach

BACKGROUND

The objective of this study is to investigate the antiproliferative, antioxidant, antimicrobial, and enzyme activity capacities and phytochemical compositions of Thymus pectinatus (TP), Thymus convolutus (TC), which are endemic to Türkiye. Quantitative analysis of phenolic compounds in the extracts was conducted using liquid chromatography-tandem mass spectrometry, targeting 53 phenolic compounds.

RESULTS

Rosmarinic acid, quinic acid, and cynaroside were identified as the major compounds, exhibiting quantitative variation in both extracts. The extracts had a high total phenolic content, with 113.57 ± 0.58 mg gallic acid equivalents (GAE)/g extract for TP and 130.52 ± 1.05 mg GAE/g extract for TC. Furthermore, although both extracts exhibited high total flavonoid content; the TP extract (75.12 ± 1.65 mg quercitin equivalents (QE)/g extract) displayed a higher flavonoid content than the TC extract (30.24 ± 0.74 mg QE/g extract) did. The extracts had a promising antiproliferative effect on C6, HeLa, and HT29 cancer cell lines with a less cytotoxic effect (10.5-14.2%) against normal cells. Both extracts exhibited very potent inhibitory activity against the xanthine oxidase enzyme, with half-maximal inhibitory concentration values of respectively 2.07 ± 0.03 μg mL-1 and 2.76 ± 0.06 μg mL-1 and moderate activity against tyrosinase and α-glucosidase. Docking simulations proved that rosmarinic acid and cynaroside, the major components of the extracts, were the most potent inhibitors of xanthine oxidase. According to antimicrobial activity results, the TC extract exhibited moderate activity against Staphylococcus aureus, and the TP extract had strong activity against both Enterococcus faecium and S. aureus.

CONCLUSION

These findings emphasize the beneficial effects of the two endemic Thymus species on human health and suggest their potential use as plant-derived bioactive agents. © 2024 Society of Chemical Industry.

Properties of active packaging of PLA-PCL film integrated with chitosan as an antibacterial agent and syzygium cumini seed extract as an antioxidant agent

Active packaging is becoming increasingly significant in the food industry. The present study aims to explore the use of Syzygium Cumini Seed Extract (SCSE) as an antioxidant and chitosan as an antibacterial agent to produce active packaging based on polylactic acid (PLA), poly ε-caprolactone (PCL), and polyethylene glycol (PEG) blend. Using advanced characterization techniques, active packaging (PLA/PCL/PEG) incorporating with 0.5 g chitosan-0.5 mL SCSE was evaluated for its mechanical, physical, structural, and antibacterial-antioxidant properties. The addition of chitosan-SCSE caused an 18.57 % increase in tensile strength and decreased the Water Vapor Transmission Rate (WVTR) by up to 52 %, whereas smooth surface microscopy indicated good compatibility between polymers and active agents. Active packaging incorporating chitosan-SCSE reduced 96.66 % of Gram-positive bacteria Staphylococcus aureus and 73.98 % of Gram-negative bacteria, Escherichia coli. During 15 days of storage, the active packaging was able to slow the increase in Total Volatile Basic Nitrogen (TVBN) in beef and prevent the decrease in vitamin C contents in pineapple.

Towards a better understanding of commonly used medicinal plants from Turkiye: Detailed phytochemical screening and biological activity studies of two Teucrium L. species with in vitro and in silico approach

ETHNOPHARMACOLOGICAL RELEVANCE

Since ancient times, Teucrium L. species have been among the most commonly used traditional medicinal plants mainly in the Mediterranean region. From tackling gastrointestinal problems to maintaining the healthy functioning of endocrine glands, and from treating malaria to severe dermatological disorders, Teucrium species are known to have extensive therapeutic applications. Teucrium polium L. and Teucrium parviflorum Schreb. are the two members of the genus that have been used in Turkish folk medicine for various medicinal purposes.

AIM OF THE STUDY

To determine the phytochemical compositions of the essential oils and ethanol extracts of Teucrium polium and Teucrium parviflorum collected from different locations in Turkiye along with the investigation of in vitro antioxidant, anticancer, antimicrobial activities, and both in vitro and in silico enzyme inhibitory activities of the extracts.

MATERIALS AND METHODS

Ethanol extracts of Teucrium polium aerial parts and roots, and aerial parts of Teucrium parviflorum were prepared. Volatile profiling of the essential oils by GC-MS, phytochemical profiling of the ethanol extracts by LC-HRMS, antioxidant activity by DPPH radical scavenging, ABTS cation radical scavenging, CUPRAC, and metal chelating activity assays, anticholinesterase, antityrosinase, antiurease, activities by different enzyme inhibitory activity assays, anticancer activity by SRB cell viability assay, and antimicrobial activity against a standard panel of bacteria and fungi by the microbroth dilution technique. Molecular docking studies were performed by Autodock Vina (Ver. 1.1.2).

RESULTS

The studied extracts were found to be quite rich in various biologically important volatile and phenolic compounds. (-)-Epigallocatechin gallate, which is a molecule renowned for having great therapeutic potential, was the major compound of all extracts. Teucrium polium aerial parts extract was revealed as a great source for naringenin with 16327 ± 685.23 μg/g extract. All extracts exerted significant antioxidant activity by different methods. All extracts demonstrated antibutrylcholinesterase, antityrosinase, and antiurease activities by in vitro and in silico assays. Teucrium polium roots extract stood out with remarkable tyrosinase and urease inhibitory and cytotoxic activities.

CONCLUSION

The obtained results from this multi-disciplinary study proves that the traditional use of these two Teucrium species is justified, and the mechanisms behind are enlightened.

The variability of phenolic constituents and antioxidant properties among wild populations of Ziziphora clinopodioides Lam

In this study, phenolic derivatives and antioxidant activities of fourteen Ziziphora clinopodioides populations, as well as LC-MS/MS analysis of three specific flavonoids were evaluated. Generally, high contents of phenolic derivatives were found in shoot extracts compared to roots. LC-MS/MS, a powerful analytical technique, was employed for the identification and quantify the individual flavonoids in Z. clinopodioides populations' extracts, in a quantity order of quercetin > rutin > apigenin. Scavenging activity by DPPH and FRAP was performed, and accordingly, in the shoot, the highest values for the DDPH were 4.61 ± 0.4 and 7.59 ± 0.26 µg ml- 1 in populations 1 and 13, respectively, and for the FRAP were 328.61 ± 5.54 and 292.84 ± 2.85 mg g DW- 1, in populations 6 and 1 respectively. Multivariate analysis results of the principal component analysis indicated the amount of polyphenols to be useful indicators in differentiating the geographical localities which explain 92.7% of the total variance. According to the results of hierarchical cluster analysis, the studied populations could be separated into two groups in that the contents of phenolic derivatives and antioxidant activities of different plant parts. Both shoot and root samples were well discriminated with the orthogonal partial least squares discriminant analysis (R2X: 0.861; Q2: 0.47) model. The validity of the model was confirmed by using receiver operating characteristic curve analysis and permutation tests. Such data make an important addition to our current knowledge of Ziziphora chemistry and are decisive in the identification of germplasms with a homogeneous phytochemical profile, high chemical content and bioactivity. The present results could also be helpful for the potential application of Z. clinopodioides in different kinds of industries as natural antioxidants.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01283-y.

Thymus hirtus Willd. ssp. algeriensis Boiss. and Reut: A Comprehensive Review on Phytochemistry, Bioactivities, and Health-Enhancing Effects

Members of the Lamiaceae family are considered chief sources of bioactive therapeutic agents. They are important ornamental, medicinal, and aromatic plants, many of which are used in traditional and modern medicine and in the food, cosmetic, and pharmaceutical industries. In North Africa, on the Mediterranean side, there is the following particularly interesting Lamiaceous species: Thymus hirtus Willd. sp. Algeriensis Boiss. Et Reut. The populations of this endemic plant are distributed from the subhumid to the lower arid zone and are mainly employed as ethnomedicinal remedies in the following Maghreb countries: Algeria, Libya, Morocco, and Tunisia. In fact, they have been applied as antimicrobial agents, antispasmodics, astringents, expectorants, and preservatives for several food products. The species is commonly consumed as a tea or infusion and is used against hypercholesterolemia, diabetes, respiratory ailments, heart disease, and food poisoning. These medicinal uses are related to constituents with many biological characteristics, including antimicrobial, antioxidant, anticancer, anti-ulcer, anti-diabetic, insecticidal, and anti-inflammatory activities. This review aims to present an overview of the botanical characteristics and geographical distribution of Thymus algeriensis Boiss. Et Reut and its traditional uses. This manuscript also examines the phytochemical profile and its correlation with biological activities revealed by in vitro and in vivo studies.

Essential Oils from Some Lamiaceae Plants: Antioxidant and Anticancer Potentials besides Thermal Properties

The purpose of this study was to determine the chemical compositions, antioxidant and anticancer activities and thermal behavior of essential oils (EOs) obtained by a microwave assisted Clevenger apparatus from Mentha longifolia subsp. typhoides var. typhoides (ML), Thymus kotschyanus var. glabrescens (TK), Calamintha nepeta subsp. nepeta (CN) and Satureja cuneifolia (SC) in Osmaniye, Turkey. Nepetalactone (34.23 %), thymol (37.40 %), piperitone oxide (27.25 %), and carvacrol (28.34 %) were major compounds in the EOs of ML, TK, CN, and SC. Total phenolic content and antioxidant activity (by FRAP assay) were in the range of 0.27-3.01 mg gallic acid equivalents and 0.62-171.14 μmol trolox equivalent per g EO, respectively. IC50 values of DPPH were mostly greater than ABTS. IC50 levels of the EOs of ML, TK, CN for the cytotoxic activities were 195.7, 265.7, 442.9 μg/ml, and 218.4, 204.2, 133.9 μg/ml for 24 and 48 h, respectively. IC50 of SC-EO could not be calculated in the applied concentration range. The highest fusion enthalpies were in between 58.72 and 81.65 kJ/kg. Both the TK and SC plant EOs had comparable and significant bioactivities. CN-EO reduced cell motility and triggered apoptosis more effectively than the others.

Unveiling Antimicrobial and Antioxidant Compositional Differences between Dukkah and Za'atar via SPME-GCMS and HPLC-DAD

Interest in plant-based diets has been on the rise in recent years owing to the potential health benefits of their individual components and the notion that plant-based diets might reduce the incidence of several diseases. Egyptian dukkah and Syrian za’atar are two of the most historic and famous Middle Eastern herbal blends used for their anti-inflammatory, hypolipidemic, and antidiabetic effects. Headspace SPME-GCMS and HPLC-DAD were adopted for characterizing the aroma profile and phenolic compounds of both herbal blends, respectively. Further, vapor-phase minimum inhibitory concentration was employed for assessing each blend’s antibacterial potential, while their antioxidant potential was estimated via in vitro antioxidant assays. SPME headspace analysis indicated the abundance of ethers and monoterpene hydrocarbons, while HPLC revealed the presence of several phenolics including rosmarinic acid, ferulic acid, and rutin. Biological investigations affirmed that vapor-phase of the tested blends exhibited antibacterial activities against Gram-positive and Gram-negative pathogens, while the antioxidant potential of the blends was investigated and expressed as Trolox (125.15 ± 5.92 to 337.26 ± 13.84 μM T eq/mg) and EDTA (18.08 ± 1.62 to 51.69 41 ± 5.33 μM EDTA eq/mg) equivalent. The presented study offers the first insight into the chemical profile and biological activities of both dukkah and za’atar.

The Therapeutic Potential of Ethnomedicinally Important Anatolian Thyme Species: A Phytochemical and Biological Assessment

Thyme has been used for various therapeutic purposes in many different cultures, which makes it one of the most riveting medicinal plants throughout history. From its beneficial effects on the respiratory tract or the gastrointestinal system, to its unique skin-related activities, the investigation of the medicinal properties of thyme has always been an alluring topic for researchers aiming to develop conventional medications from this traditional herb. With an incentive to contribute to the extensive thyme research, three Thymus L. species namely Thymus cariensis Hub-Mor. & Jalas (endemic), Thymus praceox subsp. grossheimii (Ronniger) Jalas, and Thymus pubescens Boiss. et Kotschy ex Celak from Turkey were deeply investigated within this study. The analysis of the phytochemical constituents of the extracts was conducted by LC-MS/MS. 12 biologically important secondary metabolites (p-coumaric acid, caffeic acid, salicylic acid, quinic acid, fumaric acid, vanillin, malic acid, rutin, apigenin, naringenin, and nicotiflorin) were detected in all extracts. Their total phenolic and flavonoid contents were calculated (11.15 ± 0.17-61.12 ± 2.59 μg PEs/mg extract, 2.53 ± 0.04-40.28 ± 0.92 μg QEs/mg extract, respectively), and the antioxidant potential of the extracts was evaluated by DPPH and ABTS radical scavenging and CUPRAC activity methods, accordingly, the extracts were shown to possess significant antioxidant activity. Among them, Thymus cariensis Hub-Mor. & Jalas was the most active with IC50 values of 34.97 ± 1.00 μg/ml and 9.98 ± 0.04 μg/ml regarding the DPPH and ABTS radical scavenging assays, respectively, and an A0.5 value of 5.80 ± 0.02 μg/ml according to CUPRAC activity method. Their anticholinesterase, antityrosinase, and antiurease activities were also tested, Thymus cariensis Hub-Mor. & Jalas (35.61 ± 1.20%) and Thymus pubescens Boiss. et Kotschy ex Celak aerial part extract (33.49 ± 1.39%) exhibited moderate antibutyrylcholinesterase activity at 200 μg/ml concentration. The results of the cell viability assay indicated that the extracts demonstrated moderate-to-low cytotoxicity on A498 human renal cell lines. Furthermore, all studied extracts exerted noteworthy antimicrobial activity, especially against Candida tropicalis (MIC values: 19.53-78.12 μg/ml). The presented data substantiates the use of thyme extracts as therapeutic agents in both ethnomedicine and conventional therapies.

Bioactive Compound, Antioxidant, and Radical Scavenging Activity of Some Plant Aqueous Extracts for Enhancing Shelf Life of Cold-Stored Rabbit Meat

The potential radical scavenging, antioxidant activities (DPPH and ABTS) and bioactive constituents of several plant aqueous extracts (Curcuma longa, CL; Myristica fragrans, MF; Zingiber officinale, ZO; Cymbopogon citratus, CC and Thymus vulgaris, TV as well as their mixture) were investigated. The effect of these extracts on quality aspects (sensory characteristic, color traits, and Thiobarbituric acid) of rabbit meat during a 16-day cold (4 ± 2 °C) storage were investigated. Total phenolics and flavonoid contents of all extracts ranged from 13.27 ± 0.57 to 25.23 ± 0.49 mg GAE/g and 6.57 ± 0.22 to 13.24 ± 0.19 mg quercetin/g, respectively. The aqueous extract of MF had the highest (p ≤ 0.05) ABTS scavenging activity (4.55 μ mol Te/g dry extract), whereas the highest (p < 0.05) DPPH scavenging activity was detected in ZO extract (9.32 μ mol Te/g dry extract). Identification of extracts’ bioactive compounds by GC-MS revealed that Eugenol (34.51%), Cinnamaldehyde (44.71%), Carvacrol (40.49%), Eicosane aldehyde (31.73%), and thymol (50.04%) are the first abundant bioactive compounds of CL, MF, ZO, CC, and TV aqueous extracts, respectively. Generally, the thiobarbituric acid reactive substances (TBARS) of all cold stored rabbit meat increased (p < 0.05) by increasing the storage time. The lowest TBARS values were detected for the samples treated with 0.2% of plant extracts mixture, which increased the shelf life of cold-stored rabbits by 50%. Significant (p < 0.05) increases in both L* and b* were observed with extended storage time. Meanwhile, the redness of the cold stored rabbit meat had an opposite trend. Treating the cold stored rabbit meat with 0.2% of the extract’s mixture doubled the storage time with acceptable odor and taste. The results indicated that the studied plant extracts may be effective against rancidity and may be used as a natural antioxidant to prolong the shelf life of cold-stored rabbit meat.