Chemical composition and biological activity of the essential oil from Thymus lanceolatus

Exploring the Biochemical and Nutra-Pharmaceutical Prospects of Some Thymus Species - A Review

The Thymus genus includes various medicinal and aromatic species, cultivated worldwide for their unique medicinal and economic value. Besides, their conventional use as a culinary flavoring agent, Thymus species are well-known for their diverse biological effects, such as antioxidant, anti-fungal, anti-bacterial, anti-viral, anti-tumor, anti-inflammatory, anti-cancer, and anti-hypertensive properties. Hence, they are used in the treatment of fever, colds, and digestive and cardiovascular diseases. The pharmaceutical significance of Thymus plants is due to their high levels of bioactive components such as natural terpenoid phenol derivatives (p-cymene, carvacrol, thymol, geraniol), flavonoids, alkaloids, and phenolic acids. This review examines the phytochemicals, biological properties, functional food, and nutraceutical attributes of some important Thymus species, with a specific focus on their potential uses in the nutra-pharmaceutical industries. Furthermore, the review provides an insight into the mechanisms of biological activities of key phytochemicals of Thymus species exploring their potential for the development of novel natural drugs.

Chemical Composition of the Essential Oil of Thymus longicaulis C. Presl. subsp. longicaulis

In this study, the chemical composition of the essential oils obtained from the aerial parts of Thymus longicaulis subsp. longicaulis naturally grown in Turkey were analyzed by GC and GC-MS and chemical differences in terms of chemotaxonomy were discussed. The main compounds in the essential oils of T. longicaulis subsp. longicaulis essential oils were 1,8-cineole (30.1%), linalool (18.0%), β-pinene (17.3%) and (E)-β-ocimene (%12.6%) Hierarchical cluster analysis was performed by examining essential oil studies of 34 samples belonging to the genus Thymus, including the Sinop sample. The results of the study were discussed with other taxa belonging to the genus.

The Chemical Composition and Biological Activities of Essential Oil from Korean Native Thyme Bak-Ri-Hyang (Thymus quinquecostatus Celak.)

Thymus quinquecostatus Celak. (Korean name: bak-ri-hyang) is an important medicinal and aromatic herb in Korea, which is named for the spread of its fragrance over a distance of approximately 40 km. In traditional Korean systems of medicine, T. quinquecostatus has been used to treat cancer, constipation, hepatic disease, arteriosclerosis, poor circulation in women, constipation, and menstrual irregularities. At present, T. quinquecostatus is used only for ornamental and ground cover purposes. A literature search was conducted to retrieve information regarding the essential oil composition and biological properties of T. quinquecostatus from PubMed, Science Direct, Wiley, Springer, Taylor and Francis, Wiley, and other literature databases. T. quinquecostatus can be divided into different chemotypes, such as γ-terpinene, thymol, phenol, carvacrol, and geraniol, according to the presence of major components in its essential oil. Further, the essential oil from T. quinquecostatus has been reported to possess various therapeutic properties such as antioxidant, antimicrobial, anticancer, anti-inflammatory, analgesic, sleep prolonging, soothing, skin protection and whitening, anti-aging, anti-obesity, and anti-acne properties. In conclusion, this review will be helpful for utilizing the T. quinquecostatus plant in different industries including food, pharmaceuticals, pesticides, perfumery, and cosmetics.

Newly Synthesized Thymol Derivative and Its Effect on Colorectal Cancer Cells

Thymol affects various types of tumor cell lines, including colorectal cancer cells. However, the hydrophobic properties of thymol prevent its wider use. Therefore, new derivatives (acetic acid thymol ester, thymol β-D-glucoside) have been synthesized with respect to hydrophilic properties. The cytotoxic effect of the new derivatives on the colorectal cancer cell lines HT-29 and HCT-116 was assessed via MTT assay. The genotoxic effect was determined by comet assay and micronucleus analysis. ROS production was evaluated using ROS-Glo™ H₂O₂ Assay. We confirmed that one of the thymol derivatives (acetic acid thymol ester) has the potential to have a cyto/genotoxic effect on colorectal cancer cells, even at much lower (IC₅₀~0.08 μg/mL) concentrations than standard thymol (IC₅₀~60 μg/mL) after 24 h of treatment. On the other side, the genotoxic effect of the second studied derivative-thymol β-D-glucoside was observed at a concentration of about 1000 μg/mL. The antiproliferative effect of studied derivatives of thymol on the colorectal cancer cell lines was found to be both dose- and time-dependent at 100 h. Moreover, thymol derivative-treated cells did not show any significantly increased rate of micronuclei formation. New derivatives of thymol significantly increased ROS production too. The results confirmed that the effect of the derivative on tumor cells depends on its chemical structure, but further detailed research is needed. However, thymol and its derivatives have great potential in the prevention and treatment of colorectal cancer, which remains one of the most common cancers in the world.

Discrimination of the Essential Oils Obtained from Four Apiaceae Species Using Multivariate Analysis Based on the Chemical Compositions and Their Biological Activity

The chemical composition of the essential oils obtained from the aerial parts of four Apiaceae species, namely Elaeosticta allioides (EA), E. polycarpa (EP), Ferula clematidifolia (FC), and Hyalolaena intermedia (HI), were determined using gas chromatography. Altogether, 100 volatile metabolites representing 78.97, 81.03, 85.78, and 84.49% of the total components present in EA, EP, FC, and HI oils, respectively, were reported. allo-Ocimene (14.55%) was the major component in FC, followed by D-limonene (9.42%). However, in EA, germacrene D (16.09%) was present in a high amount, while heptanal (36.89%) was the predominant compound in HI. The gas chromatographic data were subjected to principal component analysis (PCA) to explore the correlations between these species. Fortunately, the PCA score plot could differentiate between the species and correlate Ferula to Elaeosticta species. Additionally, the antioxidant activity was evaluated in vitro using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and the ferric reducing power (FRAP) assays. In addition, the antimicrobial activity using the agar diffusion method was assessed, and the minimum inhibitory concentrations (MICs) were determined. Furthermore, the cell viability MTT assay was performed to evaluate the cytotoxicity of the essential oils against hepatic (HepG-2) and cervical (HeLa) cancer cell lines. In the DPPH assay, FC exhibited the maximum activity against all the antioxidant assays with IC50 values of 19.8 and 23.0 μg/mL for the DPPH and ABTS assays, respectively. Ferula showed superior antimicrobial and cytotoxic activities as well. Finally, a partial least square regression model was constructed to predict the antioxidant capacity by utilizing the metabolite profiling data. The model showed excellent predictive ability by applying the ABTS assay.

Anti-protozoal activity of Thymol and a Thymol ester against Cryptosporidium parvum in cell culture

Cryptosporidium parvum is a protozoan parasite that infects intestinal epithelial cells causing malabsorption and severe diarrhea. The monoterpene thymol has been reported to have antifungal and antibacterial properties but less is known about the antiparasitic effect of this compound. Terpenes are sometimes unsuitable for therapeutic and food applications because of their instability. Esterification of terpenes eliminates this disadvantage. The present study evaluates the effects of thymol (Th) and a thymol ester, thymol octanoate (TO), against C. parvum infectivity in vitro. The cytotoxicity IC50 value for TO after 24 h of treatment was 309.6 μg/mL, significantly higher than that of Th (122.5 μg/mL) in a human adenocarcinoma cell line (HCT-8). In the same way, following 48 h of treatment, the cytotoxicity IC50 value for TO was significantly higher (139 μg/mL) than that of Th (75.5 μg/mL). These results indicate that esterification significantly reduces Th cytotoxicity. Dose-dependent effects were observed for TO and Th when both parasite invasion and parasite growth assays were evaluated. When evaluated for their activity against C. parvum growth cultured in vitro in HCT-8 cells, the anti-cryptosporidial IC50 values were 35.5 and 7.5 μg/mL, for TO and Th, respectively. Together, these findings indicate that esterified thymol has anti-cryptosporidial effect comparable with its parental compound thymol, but with improved safety margins in mammalian cells and better physicochemical properties that could make it more suitable for diverse applications as an antiparasitic agent.

Chemical composition, antifungal and antiproliferative activities of essential oils from Thymus numidicus L

In this study, Thymus numidicus Poir. plant material was collected from two different locations in north-western Tunisia and the aerial parts essential oils (EOs) were extracted via hydro-distillation. Gas chromatography coupled to mass spectrometry (GC-MS) and flame ionisation detection (GC-FID) were used for the qualitative analysis and quantification of the volatile constituents. Thymol (50.1-52.8%) was identified as the main compound of both EOs. To evaluate the potential application of the EOs as antifungal agents, the in vitro inhibitory effects were tested against six fungal strains; a strong antifungal activity of one sample was observed (MIC = 40-400 µg/mL). The in vitro antiproliferative activity was investigated on two human cancer cell lines, i.e. the colonic (HCT116) and breast adenocarcinoma (MCF7) using the colourimetric MTT assay. Again, the same sample demonstrated to possess good antiproliferative activity against both cancer cell lines, with IC₅₀ values of 26.9 and 11.7 µg/mL, respectively.

Volatile Antimicrobial Agents and In Vitro Methods for Evaluating Their Activity in the Vapour Phase: A Review

This review summarizes data on the in vitro antimicrobial effectiveness of volatile agents of plant origin and in vitro methods for evaluating their activity in the vapour phase. As a result of literature analysis, the antimicrobial efficacy of vapours from 122 different plant species and 19 pure compounds examined in 61 studies using different in vitro tests against a broad spectrum of microorganisms was identified and summarized. In addition, 11 different techniques found in the literature are described in detail. An original classification of methods based on the solid and liquid matrix volatilization principle is proposed because carrier medium/matrix selection is crucial for the volatilization of any agents tested. This review should be useful for medicinal, pharmaceutical, food, and agricultural experts working in areas related to the management of infectious diseases (especially respiratory and skin infections), food preservation (active packaging), and protection of agriculture products (controlled atmosphere). It may also stimulate the interest of pharmaceutical, cosmetic, food, and agriculture industries in the research and development of new antimicrobial agents of natural origin. Since several original apparatuses previously developed for antimicrobial susceptibility testing in the vapour phase are described in this review, labware manufacturers may also be interested in this topic. The review also provides specific guidelines and recommendations for researchers studying the antimicrobial activity of volatile agents. The article will therefore appeal to communities of industrial stakeholders, pharmacists, physicians, food experts, agriculturists, and researchers in related areas such as pharmacology, medicinal chemistry, microbiology, natural product chemistry, food preservation and plant protection.

Thymus lanceolatus ethanolic extract protects human cells from t-BHP induced oxidative damage

This study aimed to investigate the ethanolic extract of T. lanceolatus, a species native to north-western Algeria, traditionally used as herbal tea, seasoning and a preservative for meat and poultry. HPLC analysis showed the presence of fourteen bioactive compounds, among which rosmarinic acid is by far the most abundant one (15440.9 mg kg-1). Its biological activity on proliferation, viability and ROS protection was investigated towards K562, CaCo-2 and SH-SY5Y human cancer cell lines. Cell proliferation was inhibited in K562 and SH-SY5Y cells in the first 48 h at 500 μg mL-1 but slowly resumed after 72 h. A weak cytotoxic effect can be observed at 24, 48 and 72 hours: 12.8%, 14.9% and 24.2% reduction in K562 viability, and 11%, 15% and 12.7% in SH-SY5Y. No cytotoxicity was observed in CaCo-2 cells under the same experimental conditions. Even at the lowest concentrations (50 μg mL-1), the extract was efficiently able to protect human cells against t-BHP-induced oxidative damage. For instance, the highest concentration of the extract (100 μg mL-1) decreases ROS generation by about 30% in SH-SY5Y and 70% in CaCo-2 and K562 cells. The study confirms the very low cytotoxicity of the T. lanceolatus ethanolic extract and highlights its nutraceutical properties as an antioxidative and preservative agent and its possible use as an ingredient in functional foods.

Essential Oil Derived From Eupatorium adenophorum Spreng. Mediates Anticancer Effect by Inhibiting STAT3 and AKT Activation to Induce Apoptosis in Hepatocellular Carcinoma

Eupatorium adenophorum Spreng. (EA) is a well-known noxious invasive species. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the essential oil derived from EA (EAEO) is mainly composed of sesquiterpenes. However, the pharmacological value of EAEO in hepatocellular carcinoma (HCC) remains largely unexplored. Herein, we investigated the anti-HCC activities of EAEO, and explored the potential mechanisms of EAEO-induced apoptosis. An MTT assay showed that EAEO inhibited HCC cell proliferation with little toxicity on normal liver cells. Wound healing and FACS assays revealed that EAEO suppressed HCC cell migration and arrested cell cycle, respectively. Moreover, EAEO promoted in vitro HCC cell apoptosis, and EAEO treatment inhibited HepG2 xenografts growth and enhanced apoptotic nucleus of xenografts in HepG2-bearing nude mice. Mechanistically, EAEO significantly decreased the ratio of Bcl-2/Bax and resulted in the activation of caspase-9 and -3. EAEO also reduced the expression of Grp78, which in turn relieved the inhibition of caspase-12 and -7. Meanwhile, EAEO suppressed the phosphorylation of STAT3 and AKT, indicative of its anti-HCC potential. In summary, we determined that EAEO treatment promoted HCC apoptosis via activation of the apoptotic signaling pathway in mitochondria and endoplasmic reticulum, as well as repressed the activity of STAT3 and AKT in HCC cells.

Multi-Response Extraction Optimization Based on Anti-Oxidative Activity and Quality Evaluation by Main Indicator Ingredients Coupled with Chemometric Analysis on Thymus quinquecostatus Celak

Thymus quinquecostatus Celak is a species of thyme in China and it used as condiment and herbal medicine for a long time. To set up the quality evaluation of T. quinquecostatus, the response surface methodology (RSM) based on its 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was introduced to optimize the extraction condition, and the main indicator components were found through an UPLC-LTQ-Orbitrap MSn method. The ethanol concentration, solid-liquid ratio, and extraction time on optimum conditions were 42.32%, 1:17.51, and 1.8 h, respectively. 35 components having 12 phenolic acids and 23 flavonoids were unambiguously or tentatively identified both positive and negative modes to employ for the comprehensive analysis in the optimum anti-oxidative part. A simple, reliable, and sensitive HPLC method was performed for the multi-component quantitative analysis of T. quinquecostatus using six characteristic and principal phenolic acids and flavonoids as reference compounds. Furthermore, the chemometrics methods (principal components analysis (PCA) and hierarchical clustering analysis (HCA)) appraised the growing areas and harvest time of this herb closely relative to the quality-controlled. This study provided full-scale qualitative and quantitative information for the quality evaluation of T. quinquecostatus, which would be a valuable reference for further study and development of this herb and related laid the foundation of further study on its pharmacological efficacy.

Biological characteristics of Edgeworthia tomentosa (Thunb.) Nakai flowers and antimicrobial properties of their essential oils

Edgeworthia tomentosa (Thunb.) Nakai belongs to Thymelaeaceae family, its alabastrum is used as the traditional Chinese medicine 'Buddleja Officinalis Maxim'. The present study was to elucidate the ultrastructure characteristics of the flower, the phytochemical composition of the aroma essential oils (EOs) and the relevant antimicrobial properties. There were exclusive characters of calyx, ovule, anther and pollen grain of the flowers under scanning electron microscopy. A total of 40 phytochemical components representing 98% of the EOs were successfully identified: monoterpenes and sesquiterpenes were the dominant terpenoids according to Kovats retention index and MS database. EOs exhibited a broad spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria, the best bacteriostatic effect was against Diplococcus pneumonia with MIC and MBC values ranging between 7.8 and 62.5 and 26.0-71.0 μg/mL, respectively. These results demonstrate that the surface microscopic morphological characteristics of Edgeworthia chrysantha Lindl. flowers, are full-scale chemical composition and antimicrobial properties of the EOs.

Pharmacological Properties and Molecular Mechanisms of Thymol: Prospects for Its Therapeutic Potential and Pharmaceutical Development

Thymol, chemically known as 2-isopropyl-5-methylphenol is a colorless crystalline monoterpene phenol. It is one of the most important dietary constituents in thyme species. For centuries, it has been used in traditional medicine and has been shown to possess various pharmacological properties including antioxidant, free radical scavenging, anti-inflammatory, analgesic, antispasmodic, antibacterial, antifungal, antiseptic and antitumor activities. The present article presents a detailed review of the scientific literature which reveals the pharmacological properties of thymol and its multiple therapeutic actions against various cardiovascular, neurological, rheumatological, gastrointestinal, metabolic and malignant diseases at both biochemical and molecular levels. The noteworthy effects of thymol are largely attributed to its anti-inflammatory (via inhibiting recruitment of cytokines and chemokines), antioxidant (via scavenging of free radicals, enhancing the endogenous enzymatic and non-enzymatic antioxidants and chelation of metal ions), antihyperlipidemic (via increasing the levels of high density lipoprotein cholesterol and decreasing the levels of low density lipoprotein cholesterol and low density lipoprotein cholesterol in the circulation and membrane stabilization) (via maintaining ionic homeostasis) effects. This review presents an overview of the current in vitro and in vivo data supporting thymol's therapeutic activity and the challenges concerning its use for prevention and its therapeutic value as a dietary supplement or as a pharmacological agent or as an adjuvant along with current therapeutic agents for the treatment of various diseases. It is one of the potential candidates of natural origin that has shown promising therapeutic potential, pharmacological properties and molecular mechanisms as well as pharmacokinetic properties for the pharmaceutical development of thymol.

Use of traditional plants in management of halitosis in a Moroccan population

Introduction:

The use of medicinal plants was a very spread therapeutic way. At present, several studies are moving toward this ancestral option, seen the emergence of several bacterial resistance and for the large number of side effects of some synthetic drugs.

Objective:

The objective of this study was to collect and evaluate information on medicinal plants commonly used in five Moroccan cities: Rabat, Salé, Témara, Khémisset, and Tiflet for the management of halitosis.

Methods:

This is a cross-sectional survey; conducted among 171 herbalists. The tool of the study was a questionnaire filled by herbalists. SPSS in its version 13 was used for statistical calculations. Quantitative variables were expressed as a mean and standard deviation. Categorical variables were expressed as numbers and percentage.

Results:

Analysis of the results of this study identified 23 plants that are used the most. The herbal knowledge herbalists prescribed on the toxicity of plants and their side effects were appreciated.

Conclusions:

Preliminary results presented in this work allow knowing the plants used by this population. This data could be the basis for experimental and clinical studies to promote the use of natural agents in the treatment of bad breath.

Evaluation of antibacterial potential and toxicity of plant volatile compounds using new broth microdilution volatilization method and modified MTT assay

With aim to develop effective proof-of-concept approach which can be used in a development of new preparations for the inhalation therapy, we designed a new screening method for simple and rapid simultaneous determination of antibacterial potential of plant volatiles in the liquid and the vapour phase at different concentrations. In addition, EVA (ethylene vinyl acetate) capmat™ as vapour barrier cover was used as reliable modification of thiazolyl blue tetrazolium bromide (MTT) assay for cytotoxicity testing of volatiles on microtiter plates. Antibacterial activity of carvacrol, cinnamaldehyde, eugenol, 8-hydroxyquinoline, thymol and thymoquinone was determined against Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pneumoniae using new broth microdilution volatilization method. The cytotoxicity of these compounds was evaluated using MTT test in lung fibroblast cells MRC-5. The most effective antibacterial agents were 8-hydroxyquinoline and thymoquinone with the lowest minimum inhibitory concentrations (MICs) ranging from 2 to 128μg/mL, but they also possessed the highest toxicity in lung cell lines with half maximal inhibitory concentration (IC₅₀) values 0.86-2.95μg/mL. The lowest cytotoxicity effect was identified for eugenol with IC₅₀ 295.71μg/mL, however this compound produced only weak antibacterial potency with MICs 512-1024μg/mL. The results demonstrate validity of our novel broth microdilution volatilization method, which allows cost and labour effective high-throughput antimicrobial screening of volatile agents without need of special apparatus. In our opinion, this assay can also potentially be used for development of various medicinal, agricultural, and food applications that are based on volatile antimicrobials.

Chemical Composition and In Vitro Antioxidant, Cytotoxic, Antimicrobial, and Larvicidal Activities of the Essential Oil of Mentha piperita L. (Lamiaceae)

The essential oil was obtained by hydrodistillation and the identification and quantification of components were achieved with the use of GC-MS analysis. The antioxidant activity was evaluated by the method of sequestration of DPPH. Essential oils were used for study the cytotoxic front larvae of Artemia salina. In the evaluation of the antimicrobial activity of essential oils, we employed the disk-diffusion method. The potential larvicide in mosquito larvae of the third stage of development of Aedes aegypti to different concentrations of essential oils was evaluated. The major compounds found in the essential oils of M. piperita were linalool (51.8%) and epoxyocimene (19.3%). The percentage of antioxidant activity was 79.9 ± 1.6%. The essential oil showed LC₅₀ = 414.6 μg/mL front of A. saline and is considered highly toxic. It shows sensitivity and halos significant inhibition against E. coli. The essential possessed partial larvicidal efficiency against A. aegypti.