Plants belonging to the genus Thymus as antibacterial agents: from farm to pharmacy

Molecular targets of curcumin in breast cancer (Review)

Curcumin (diferuloylmethane), an orange‑yellow component of turmeric or curry powder, is a polyphenol natural product isolated from the rhizome of Curcuma longa. For centuries, curcumin has been used in medicinal preparations and as a food colorant. In recent years, extensive in vitro and in vivo studies have suggested that curcumin possesses activity against cancer, viral infection, arthritis, amyloid aggregation, oxidation and inflammation. Curcumin exerts anticancer effects primarily by activating apoptotic pathways in cancer cells and inhibiting pro‑cancer processes, including inflammation, angiogenesis and metastasis. Curcumin targets numerous signaling pathways associated with cancer therapy, including pathways mediated by p53, Ras, phosphatidylinositol‑3‑kinase, protein kinase B, Wnt‑β catenin and mammalian target of rapamycin. Clinical studies have demonstrated that curcumin alone or combined with other drugs exhibits promising anticancer activity in patients with breast cancer without adverse effects. In the present review, the chemistry and bioavailability of curcumin and its molecular targets in breast cancer are discussed. Future research directions are discussed to further understand this promising natural product.

Preservative effect of Chinese cabbage (Brassica rapa subsp. pekinensis) extract on their molecular docking, antioxidant and antimicrobial properties

This study aimed at investigating the antimicrobial activity of different solvent extracts of Chinese cabbage Brassica rapa subsp. pekinensis (BRARP) and their antioxidant and cytotoxicity properties. Of the different solvents extracts, the chloroform extracts (CE) were significantly inhibited the bacterial pathogens at minimum inhibitory concentration (MIC) of 16.5 mg.mL^-1. Biochemical analysis revealed that total phenol (62.6 ± 0.05 mg GAE.g^-1) and flavonoids (27.6 ± 0.04 mg QE.g^-1) were higher in the extracts of BRARP, which resulted in enhanced antioxidant activity in CE. A total of eight dominant compounds were detected in the potent antimicrobial extract from BRARP based on GC-MS analysis. The molecular interactions study revealed that, among the screened compounds the 1,2-benzenedicarboxylic acid and 2,3-dicyanopropionamide interacted with the active site of pathogenicity and survival related protein with lipopolysaccharide (LpxC) with higer binding energy. This work concluded that the 1, 2-Benzenedicarboxylic acid and 2, 3-Dicyanopropionamide from BRARP was reported to be good non-cytotoxic and antioxidant antimicrobials against bacterial pathogens.

The anticonvulsant and anti-plasmid conjugation potential of Thymus vulgaris chemistry: An in vivo murine and in vitro study

The high-performance counter-current chromatography was used for the efficient purification of single constituents from Thymus vulgaris essential oil. Mixtures of n-heptane, ethyl acetate, methanol, and water (5:2:5:2 and 4:1:4:1 v/v), allowed purification of eugenol, 1-octen-3- ol, borneol, thymol, terpinen-4-ol, and camphor, while n-hexane, acetonitrile, and tert-butyl methyl ether (1:1:0.1 v/v) yielded carvacrol, borneol, linalyl acetate, caryophyllene oxide, p-cymene, and eucalyptol. The anticonvulsant activities were evaluated in the maximal electroshock-induced seizure test in mice model (systemic i. p. administration). The oil exerted protection against MES-induced seizures when administered 15 and 30 min before the tests (50 and 62.5%, respectively). Among the isolates, borneol, thymol, and eugenol exerted the strongest protection against seizures. Moreover, linalool had the ability to reduce the transfer of the pKM101 plasmid by 84%, what has the potential to reduce virulence and resistance spread in E. coli. No acute toxic effects towards the CNS were noticed either for the essential oil or for single compounds, in the chimney and grip-strength tests. The preclinical screening of Thymus vulgaris EO, as well as isolated terpenoids, provides evidence that the EO has partial protective activity against seizures and HPCCC technique is suitable for its large scale isolation.

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.

Extraction-free colorimetric determination of thymol and carvacrol isomers in essential oils by pH-dependent formation of gold nanoparticles

An extraction-free method is described for the colorimetric determination of thymol (TY) and carvacrol (CA) isomers in essential oils by making use of the pH-dependent formation of gold nanoparticles (AuNPs). In solutions of pH 12, TY and CA form gold nanoparticles, while at pH ≤ 11 only CA does so. By taking advantage of this finding, two different approaches based on colorimetric assay (absorption at 550 nm) were developed: one at pH 12 for the determination of total CA and TY, and other at pH 9 and pH 12 for differential quantification of TY and CA. The former agrees with the well-established Folin-Ciocalteu method, and the latter provides a simple way for calculation of TY/CA ratio. The linear ranges are from 100 to 1000 μM at pH 9, and from 50 to 200 μM at pH 12. The limits of detection are 0.09 μM at pH 9, and 0.02 μM at pH 12. These features make this method simple, fast and reliable. Conceivably, it can be used to assess the quality of essential oils and may become a valuable alternative to more sophisticated, laborious and high time-consuming methods. Graphical abstract Schematic of the assay: At pH 12 (blue color), thymol and carvacrol form gold nanoparticles (Au), while at pH 9 (red color) only carvacrol does so. This finding resulted in a colorimetric method for the differential quantification of both compounds in essential oils.

The natural plant compound carvacrol as an antimicrobial and anti-biofilm agent: mechanisms, synergies and bio-inspired anti-infective materials

Carvacrol (5-isopropyl-2-methyl phenol) is a natural compound that occurs in the leaves of a number of plants and herbs including wild bergamot, thyme and pepperwort, but which is most abundant in oregano. The aim of this review is to analyse the scientific data from the last five years (2012-2017) on the antimicrobial and anti-biofilm activities of carvacrol, targeting different bacteria and fungi responsible for human infectious diseases. The antimicrobial and anti-biofilm mechanisms of carvacrol and its synergies with antibiotics are illustrated. The potential of carvacrol-loaded anti-infective nanomaterials is underlined. Carvacrol shows excellent antimicrobial and anti-biofilm activities, and is a very interesting bioactive compound against fungi and a wide range of Gram-positive and Gram-negative bacteria, and being active against both planktonic and sessile human pathogens. Moreover, carvacrol lends itself to being combined with nanomaterials, thus providing an opportunity for preventing biofilm-associated infections by new bio-inspired, anti-infective materials.

Extraction of bioactive compounds and essential oils from mediterranean herbs by conventional and green innovative techniques: A review

Market interest in aromatic plants from the Mediterranean is continuously growing mainly due to their medicinal and bioactive compounds (BACs) with other valuable constituents from essential oils (EOs). From ancient times, these plants have been important condiments for traditional Mediterranean cuisine and remedies in folk medicine. Nowadays, they are considered as important factors for food quality and safety, due to prevention of various deteriorative factors like oxidations and microbial spoilage. EOs have different therapeutic benefits (e.g. antioxidant, anti-inflammatory, antimicrobial, and antifungal), while BACs mostly affect nutritive, chemical, microbiological, and sensory quality of foods. Currently, many plant extracts are used for functional (healthy) foods, which additionally fuels consumer and industrial interest in sustainable and non-toxic routes for their production. EO yields from dried plants are below 5%. Their extraction is strongly dependent on the hydrophobic or lipophilic character of target molecules, hence the common use of organic solvents. Similarly, BACs encompass a wide range of substances with varying structures as reflected by their different physical/chemical qualities. Thus, there is a need to identify optimal non-toxic extraction method(s) for isolation/separation of EO/BCs from plants. Various innovative non-thermal extractions (e.g. ultrasound-, high-pressure-, pulsed electric fields assisted extraction, etc.) have been proposed to overcome the above mentioned limitations. These techniques are "green" in concept, as they are shorter, avoid toxic chemicals, and are able to improve extract yields and quality with reduced consumption of energy and solvents. This research provides an overview of such extractions of both BAC and EOs from Mediterranean herbs, sustained by innovative and non-conventional energy sources.

Antibacterial activity of Thymus vulgaris essential oil alone and in combination with cefotaxime against blaESBL producing multidrug resistant Enterobacteriaceae isolates

The aim was to evaluate the susceptibility of bla_ESBL producing Enterobacteriaceae to Slovakian Thymus vulgaris essential oil (TVEO) alone and in combination with cefotaxime (CTX). TVEO composition was determined by gas chromatograph-mass spectrometer (GC/MS). Susceptibility to 21 antibiotics was determined by disc diffusion assay. Genes characterization for resistance to β-lactams was accomplished by polymerase chain reaction (PCR). The antibacterial activity was investigated by standard methods. The synergistic interaction was determined by checkerboard test. Thymol (34.5%), p-cymene (22.27%) and linalool (5.35%) were the major components present in the TVEO. The identified strains were multi-drug resistant (MDR). TVEO showed high activity against all MDR strains, including bla_ESBL producing isolates, with inhibition zones and MIC values in the range of 24-40 mm/10μL and 2.87-11.5 μg/mL, respectively. TVEO in combination with CTX showed a synergistic action against bla_SHV-12 producing Escherichia coli (FICI 0.28) and an additive effect vs ESBL producing Enterobacter cloacae (FICI 0.987).

Use of Pinus sylvestris L. (Pinaceae), Origanum vulgare L. (Lamiaceae), and Thymus vulgaris L. (Lamiaceae) essential oils and their main components to enhance itraconazole activity against azole susceptible/not-susceptible Cryptococcus neoformans strains

Background

Cryptococcal infections, besides being a problem for immunocompromised patients, are occasionally being a problem for immunocompetent patients. In addition, the lower susceptibility of this yeast to azoles is a growing problem in health care. To date, there are very few molecules with any activity towards Cryptococcus neoformans, leading to heightened interest in finding new alternatives or adjuvants to conventional drugs for the treatment of mycosis caused by this yeast. Since the essential oils (EOs) are considered as a potential rich source of bioactive antimicrobial compounds, we evaluated the antifungal activity of Origanum vulgare (oregano), Pinus sylvestris (pine), and Thymus vulgaris (thyme red) EOs, and their components (α-pinene, carvacrol, thymol) compared with fluconazole, itraconazole, and voriconazole, against C.neoformans clinical strains. Then, we investigated the effect of EOs and components in combination with itraconazole.

Methods

EO composition was analysed by Gas chromatography-mass spectrometry (GC-MS). A broth microdilution method was used to evaluate the susceptibility of C.neoformans to azoles, EOs and components. Checkerboard tests, isobolograms and time-kill assays were carried out for combination studies.

Results

Six C.neoformans isolates were susceptible to azoles, while one C.neoformans exhibited a reduced susceptibility to all tested azole drugs. All EOs exerted a good inhibitory activity against all C.neoformans strains. Pine EO was the most effective. Among components, thymol exerted the most remarkable activity. By checkerboard testing and isobolographic analysis, combinations of itraconazole with oregano, pine, or thyme EOs, and carvacrol were found to be synergistic (FICI≤0.5) against azole susceptible C.neoformans. Regarding the azole not susceptible C.neoformans strain, the synergistic effect with itraconazole was observed with thyme EO (chemotype: thymol 26.52%; carvacrol 7.85%), and carvacrol. Time-kill assays confirmed the synergistic effects of itraconazole and oregano or thyme EO against azole susceptible C.neoformans. Binary mixtures of itraconazole/thyme EO or carvacrol yielded additive effects on the azole not susceptible C.neoformans.

Conclusions

Our findings highlight the potential effectiveness of thyme, oregano EOs, and carvacrol as natural and cost-effective adjuvants when used in combination with itraconazole. Identification of EOs exerting these effects could be one of the feasible ways to overcome drug resistance, reducing drug concentration and side effects.

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.

Qualitative and Quantitative Phytochemical Analysis of Different Extracts from Thymus algeriensis Aerial Parts

This study was performed to evaluate the metabolite recovery from different extraction methods applied to Thymus algeriensis aerial parts. A high-performance liquid chromatographic method using photodiode array detector with gradient elution has been developed and validated for the simultaneous estimation of different phenolic compounds in the extracts and in their corresponding purified fractions. The experimental results show that microwave-assisted aqueous extraction for 15 min at 100 °C gave the most phenolics-enriched extract, reducing extraction time without degradation effects on bioactives. Sixteen compounds were identified in this extract, 11 phenolic compounds and five flavonoids, all known for their biological activities. Color analysis and determination of chlorophylls and carotenoids implemented the knowledge of the chemical profile of this plant.

Effect of pH and Mexican Oregano (Lippia berlandieri Schauer) Essential Oil Added to Carboxymethyl Cellulose and Starch Edible Films on Listeria monocytogenes and Staphylococcus aureus

The aim of this work was to evaluate the effect of pH and Mexican oregano essential oil (MOEO) added to carboxymethyl cellulose (CMC) and starch (S) edible films on Listeria monocytogenes and Staphylococcus aureus. CMC and S edible films were formulated with different concentrations (0%, 0.25%, 0.50%, 0.75%, and 1%) of MOEO at different pH (5, 6, or 7). Antimicrobial assay was performed. Inhibition curves were fitted to the Fermi model. Significant differences (p<0.05) were found in tc (time to reduce 50% of microbial population) and a (slope of the curve around tc), being lower at acidic pH. For L. monocytogenes, CMC films exhibited a higher antimicrobial effectiveness (0.50% of MOEO) compared to S films which need a higher concentration of MOEO (0.75%). S. aureus was inhibited with CMC films at 0.50% MOEO and pH 5 and 6. Microbial modeling has allowed estimating key intrinsic factors as pH and MOEO concentration with the synergistic effect against two important food-borne pathogens.

Myricetin Inhibits Angiogenesis by Inducing Apoptosis and Suppressing PI3K/Akt/mTOR Signaling in Endothelial Cells

Background

Myricetin has been shown to possess potential antiangiogenic effects in endothelial cells. However, the underlying mechanisms are not fully understood. Therefore, we evaluated its antiangiogenic effects in human umbilical vascular endothelial cells (HUVECs).

Methods

HUVECs were cultured in endothelial cell growth medium-2 to induce proliferation and angiogenesis and treated with different doses of myricetin (0.25, 0.5, and 1 μM) for 24 hours. Cell proliferation was analyzed by the MTT and lactate dehydrogenase release assays; angiogenesis was determined by the tube formation assay. In addition, cell signaling pathways related to angiogenesis were investigated by Western blotting.

Results

Myricetin induced apoptosis and procaspase-3 cleavage though the induction of reactive oxygen species (ROS). It significantly inhibited cell migration, tube formation, and PI3K/Akt/mTOR signaling in HUVECs.

Conclusions

Myricetin exerts antiangiogenic effects by inducing ROS-mediated apoptosis and inhibiting PI3K/Akt/mTOR signaling in HUVECs.

Phytochemical investigations and antiproliferative secondary metabolites from Thymus alternans growing in Slovakia

CONTEXT

Thymus alternans Klokov (Lamiaceae) is a neglected species of the genus Thymus (Sect. Serpyllum) endemic to Carpathian area, where it is used as a flavouring agent and for medicinal purposes.

OBJECTIVE

The aim of the work was to identify antiproliferative constituents from the flowering aerial parts of this plant.

MATERIALS AND METHODS

Thymus alternans extracts were analyzed by HPLC-MSⁿ and subjected to extensive chromatographic separations. The isolated compounds (phenolics and triterpenes) were structurally elucidated by MS and 1D and 2D NMR experiments. Essential oil (EO) composition was determined by GC-FID and GC-MS. Six purified triterpenes and EO were assayed for in vitro antiproliferative activity against a panel of human cancer cells, namely, breast (MDA-MB 231), colon (HCT-15 and HCT116), lung (U1810), pancreatic (BxPC3), melanoma (A375) and cervical carcinoma (A431) cells.

RESULTS

The structures of the isolated compounds were achieved on the basis of H-NMR and MS experiments. Luteolin-4'-O-β-d-glucopyranoside (P1), chrysoeriol-7-O-β-d-glucopyranoside (P2), chrysoeriol-5-O-β-d-glucopyranoside (P3), apigenin-7-O-β-d-glucopyranoside (P4), rosmarinic acid (P5), rosmarinic acid-3'-O-β-d-glucopyranoside (P6), caffeic acid-3-O-β-d-glucopyranoside (P7), 3α-hydroxy-urs-12,15-diene (T1), α-amyrin (T2), β-amyrin (T3), isoursenol (T4), epitaraxerol (T5), and oleanolic acid (T6). GC-MS analysis revealed that the EO of T. alternans was devoid of phenols and belonged to the nerolidol-chemotype, that is typical of the Sect. Serpyllum. The six purified triterpenes (T1-T6) were active with IC₅₀ ranging from 0.5 to 5 μM being comparable or better than those of reference compounds betulinic acid and cisplatin. The EO exhibited significant effects on A375, MDA-MB 231 and HCT116 cell lines with IC₅₀ in the range of 5-8 μg/mL.

CONCLUSION

The reported results suggest that T. alternans can be considered as a good source of phytoconstituents with possible importance in the pharmaceutical field.

Chemoinformatic Investigation of Antibiotic Antagonism: The Interference of Thymus glabrescens Essential Oil Components with the Action of Streptomycin

Given the importance of Thymus glabrescens as a useful antibacterial remedy, we have evaluated the antibacterial and streptomycin-modifying activity of Thymus glabrescens essential oil, geraniol, geranyl acetate and thymol. It was shown that all substance-streptomycin combinations produced predominantly antagonistic interactions. Furthermore, combinations between geraniol and thymol showed dominant additive effect. Chemoinformatics results, combined with experimental data, suggest that antagonistic interactions with streptomycin were not a consequence of the antimicrobial action at the same target, but an outcome of the membrane impairment, followed by the membrane potential/proton motive force dissipation, which decreased the streptomycin uptake. Furthermore, the membrane toxicity of geraniol and thymol was confirmed by their additive antibacterial interactions and parameters of their penetration and accumulation throughout a cell membrane. This study should greatly help in an intelligent and a controlled pharmacomodulation of antibiotics.

Development of antimicrobial nanoemulsion-based delivery systems against selected pathogenic bacteria using a thymol-rich Thymus daenensis essential oil

AIMS

Thymol-rich medicinal plants have been used in traditional medicine to relieve infectious diseases. However, the application of essential oils as medicine is limited by its low water solubility and high vapour pressure. The objective of this study was to produce stable nanoemulsions of Thymus daenensis oil in water by preventing Ostwald ripening and phase separation.

METHODS AND RESULTS

The antibacterial activity of bulk and emulsified essential oil against selected pathogenic bacteria including Gram-negative (Haemophilus influenzae, Pseudomonas aeruginosa) and Gram-positive (Streptococcus pneumoniae) were investigated in the liquid and vapour phase. The optimum formulation (L2) contained 2% Tween 80 (surfactant) and 0·1% lecithin (cosurfactant) had a mean droplet diameter of 131 nm. In the liquid phase, the optimized nanoemulsion exhibited good antibacterial activity against S. pneumonia with MIC value of 0·0039 mg mL^-1 . In the vapour phase, the MIC values against S. pneumonia were similar (<7·35 μL L^-1 ) for both bulk and emulsified essential oil. However, there was no antibacterial activity in the vapour phase against H. influenzae and P. aeruginosa. Analysis of thymol concentration in the head space indicated that the nanoemulsion retarded the release of thymol into the vapour phase.

CONCLUSIONS

These findings highlight the potential applications of nanoemulsions containing essential oils as antibacterial products.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of the current study highlight the advantages of nanoemulsification for improvement of the physicochemical properties and the antibacterial activity of T. daenensis EOs in the liquid and vapour phase for therapeutic purposes.

Effect of Plant Essential Oils against Rophalosiphum padi on Wheat and Barley

The aim of the present study was to evaluate the effect of six EOs against Rhopalosiphum padi L. (Homoptera: Aphididae). This aphid is one of the most important cereal pests worldwide. EOs used in this study were from cumin ( Cuminum cyminum L.; Apiaceae), hyssop ( Hyssopus officinalis L.; Lamiaceae), costmary ( Tanacetum balsamita L. syn. Chrysanthemum balsamita L. Baill; Asteraceae), lovage ( Levisticum officinale W.D.J. Koch; Apiaceae), lavander ( Lavandula angustifolia Mill; Lamiaceae) and thyme ( Thymus vulgaris L.; Lamiaceae). Cultivar ORCF-10, a soft white winter wheat ( Triticum aestivum L.) cultivar and barley ( Hordeum vulgare L.) cv. ‘Alba’ were selected for the bioassays. Each EO was diluted with acetone (w/v) at different concentrations ranging from 0.1 % to 1.0 %. Number of R. padi landing on treated or untreated leaves was counted 24 h after the initial aphid transfer. In general, the repellency effect increased as the concentration of EOs increased regardless of treatments with the exception of lovage. Regardless of the substrate and treatment, lower numbers of aphids were observed on treated leaves at higher concentrations compared to the untreated control stressing the repellency effect. This study demonstrated that the EOs of cumin, hyssop, costmary, lavender, and thyme may have potential for aphids control.

Systematic review and technological overview of the antimicrobial activity of Tagetes minuta and future perspectives

ETHNOPHARMACOLOGICAL RELEVANCE

The antimicrobial potential of Tagetes minuta was correlated with its traditional use as antibacterial, insecticidal, biocide, disinfectant, anthelminthic, antifungal, and antiseptic agent as well as its use in urinary tract infections.

AIM OF THE STUDY

This study aimed to systematically review articles and patents regarding the antimicrobial activity of T. minuta and give rise to perspectives on this plant as a potential antimicrobial agent.

MATERIALS AND METHODS

A literature search of studies published between 1997 and 2015 was conducted over five databases: MedLine (PubMed), Web of Science, Scopus, Google Scholar, Portal de Periódicos Capes and SciFinder, grey literature was explored using the System for Information on Dissertations database, and theses were searched using the ProQuest Dissertations and Theses Full text database and the Periódicos Capes Theses database. Additionally, the following databases for patents were analysed: United States Patent and Trademark Office (USPTO), Google Patents, National Institute of Industrial Property (INPI) and Espacenet patent search (EPO). The data were tabulated and analysed using Microsoft Office Excel 2010.

RESULTS

After title screening, 51 studies remained and this number decreased to 26 after careful examinations of the abstracts. The full texts of these 26 studies were assessed to check if they were eligible. Among them, 3 were excluded for not having full text access, and 11 were excluded because they did not fit the inclusion criteria, which left 10 articles for this systematic review. The same process was conducted for the patent search, resulting in 4 patents being included in this study.

CONCLUSION

Recent advances highlighted by this review may shed light on future directions of studies concerning T. minuta as a novel antimicrobial agent, which should be repeatedly proven in future animal and clinical studies. Although more evidence on its specificity and clinical efficacy are necessary to support its clinical use, T. minuta is expected to be a highly effective, safe and affordable treatment for infectious diseases.

Update on Monoterpenes as Antimicrobial Agents: A Particular Focus on p-Cymene

p-Cymene [1-methyl-4-(1-methylethyl)-benzene] is a monoterpene found in over 100 plant species used for medicine and food purposes. It shows a range of biological activity including antioxidant, anti-inflammatory, antinociceptive, anxiolytic, anticancer and antimicrobial effects. This last property has been widely investigated due to the urgent need for new substances with antimicrobial properties, to be used to treat communicable diseases whose diffusion in developed countries has been facilitated by globalization and the evolution of antimicrobial resistance. This review summarizes available scientific data, as reported by the most recent studies describing the antimicrobial activity of p-cymene either alone, or as the main component of plant extracts, as well as addressing the mechanisms of action of cymenes as antimicrobial agents. While p-cymene is one of the major constituents of extracts and essential oils used in traditional medicines as antimicrobial agents, but considering the limited data on its in vivo efficacy and safety, further studies are required to reach a definitive recommendation on the use and beneficial effects of p-cymene in human healthcare and in biomedical applications as a promising candidate to functionalize biomaterials and nanomaterials.

Grasslands: A Source of Secondary Metabolites for Livestock Health

The need for environmentally friendly practices in animal husbandry, in conjunction with the reduction of the use of synthetic chemicals, leads us to reconsider our agricultural production systems. In that context, grassland secondary metabolites (GSMs) could offer an alternative way to support to livestock health. In fact, grasslands, especially those with high dicotyledonous plant species, present a large, pharmacologically active reservoir of secondary metabolites (e.g., phenolic compounds, alkaloids, saponins, terpenoids, carotenoids, and quinones). These molecules have activities that could improve or deteriorate health and production. This Review presents the main families of GSMs and uses examples to describe their known impact on animal health in husbandry. Techniques involved for their study are also described. A particular focus is put on anti-oxidant activities of GSMs. In fact, numerous husbandry pathologies, such as inflammation, are linked to oxidative stress and can be managed by a diet rich in anti-oxidants. The different approaches and techniques used to evaluate grassland quality for livestock health highlight the lack of efficient and reliable technics to study the activities of this complex phytococktail. Better knowledge and management of this animal health resource constitute a new multidisciplinary research field and a challenge to maintain and valorize grasslands.

Inhibition of Salmonella by thyme essential oil and its effect on microbiological and sensory properties of minced pork meat packaged under vacuum and modified atmosphere

The antibacterial activity of thyme essential oil (TEO) was evaluated against four serovars of Salmonella (S. Enteritidis, S. Typhimurium, S. Montevideo and S. Infantis), experimentally inoculated (10⁶CFU/g) in minced pork, which was treated with different concentrations of the TEO (0.3%, 0.6% and 0.9%) packaged under vacuum or MAP (30%O₂/50%CO₂/20% N₂) and stored at 3±1°C for 15days. GC-MS analysis of the TEO was performed in order to determine composition, and the predominant constituent was thymol (50.48%), followed by p-cymene and linalool. The minimum inhibitory concentration was determined for each Salmonella serovar studied. Among the tested active compounds, thymol and carvacrol exhibited the greatest inhibitory effect followed by TEO, with minimum inhibitory concentrations of 320 to 640μg/ml. S. Enteritidis was the most sensitive serovar. During the storage period, Salmonella counts in pork were reduced by 1.69-4.05logCFU/g. The influence of TEO on Enterobacteriaceae, lactic acid bacteria and total viable count was determined in control mince with no added Salmonella. The most pronounced antibacterial effect was achieved by the combination MAP and 0.9% TEO. Although the antibacterial activities of all studied concentrations of TEO in pork were evident and significant (P<0.05), sensory analysis showed that 0.3% TEO was the most acceptable to trained panellists.

Antibacterial and Antifungal Activities of Spices

Infectious diseases caused by pathogens and food poisoning caused by spoilage microorganisms are threatening human health all over the world. The efficacies of some antimicrobial agents, which are currently used to extend shelf-life and increase the safety of food products in food industry and to inhibit disease-causing microorganisms in medicine, have been weakened by microbial resistance. Therefore, new antimicrobial agents that could overcome this resistance need to be discovered. Many spices-such as clove, oregano, thyme, cinnamon, and cumin-possessed significant antibacterial and antifungal activities against food spoilage bacteria like Bacillus subtilis and Pseudomonas fluorescens, pathogens like Staphylococcus aureus and Vibrio parahaemolyticus, harmful fungi like Aspergillus flavus, even antibiotic resistant microorganisms such as methicillin resistant Staphylococcus aureus. Therefore, spices have a great potential to be developed as new and safe antimicrobial agents. This review summarizes scientific studies on the antibacterial and antifungal activities of several spices and their derivatives.

Combined treatment of Thymus vulgaris L., Rosmarinus officinalis L. and Myrtus communis L. essential oils against Salmonella typhimurium: Optimization of antibacterial activity by mixture design methodology

To increase the sensibility of Salmonella typhimurium strain, a mixture of Thymus vulgaris L. (T. vulgaris L.), Rosmarinus officinalis L. (R. officinalis L.) and Myrtus communis L. (M. communis L.) essential oils (EOs) was used in combined treatment by experimental design methodology (mixture design). The chemical composition of EOs was firstly identified by GC and GC/MS and their antibacterial activity was evaluated. The results of this first step have shown that thymol and borneol were the major compounds in T. vulgaris and M. communis L. EOs, respectively, while 1,8-cineole and α-pinene were found as major compounds in R. officinalis L. The same results have shown a strong antibacterial activity of T. vulgaris L. EO followed by an important power of M. communis L. EO against a moderate activity of R. officinalis L. EO. Besides, 1/20 (v/v) was the concentration giving a strain response classified as sensitive. From this concentration, the mixture design was performed and analyzed. The optimization of mixtures antibacterial activities has highlighted the synergistic effect between T. vulgaris L. and M. communis L. essential oils. A formulation comprising 55% of T. vulgaris L. and 45% of M. communis L. essential oils, respectively, can be considered for the increase of Salmonella typhimurium sensibility.

Oleuropein and Cancer Chemoprevention: The Link is Hot

Cancer comprises a collection of related diseases characterized by the existence of altered cellular pathways resulting in an abnormal tendency for uncontrolled growth. A broad spectrum, coordinated, and personalized approach focused on targeting diverse oncogenic pathways with low toxicity and economic natural compounds can provide a real benefit as a chemopreventive and/or treatment of this complex disease. Oleuropein, a bioactive phenolic compound mainly present in olive oil and other natural sources, has been reported to modulate several oncogenic signalling pathways. This review presents and critically discusses the available literature about the anticancer and onco-suppressive activity of oleuropein and the underlying molecular mechanisms implicated in the anticarcinogenic and therapeutic effects. The existence of limitations and the promising perspectives of research on this phenolic compound are also critically analyzed and discussed.

The Effect of Carvacrol on Inflammatory Pain and Motor Coordination in Rats

Carvacrol is a monoterpenic phenol and an active ingredient of the plant essential oils of the family Lamiaceae. We have investigated the analgesic effect of carvacrol, the possible dependence of the effect in relation to animal sex, and the impact of carvacrol on motor coordination in rats. Hyperalgesia was induced by formalin (1.5%), which was administered SC in the upper lip of rat. Hyperalgesia and effects of carvacrol and indomethacin were measured by using the orofacial formalin test. The influence on motor coordination in animals treated with carvacrol was investigated by using the rota-rod test. Carvacrol administered PO in pre-treatment (45 min. prior to formalin) at a single dose of 50, 75 and 100 mg /kg BW, in the male, 50 and 100 mg /kg BW, in female rats caused a dose-dependent antinociceptive effect. This effect of carvacrol was significantly higher (P<0.01, P<0.001) in male rats. Compared with indomethacin administered during pre-treatment (2 mg/kg, PO), carvacrol (100 mg/kg) exhibits significantly higher (P <0.05 and P <0.001) antinociceptive effect on formalininduced hyperalgesia in male rats. In the rota-rod test carvacrol did not disturb the motor coordination in male rats, nor the dose of carvacrol with clear antinociceptive properties exhibited depressive effect on the CNS of treated rats. Keeping in mind that the monoterpene carvacrol is of plant origin, with potentially less side effects and without residues, it is realistic to expect the possibility of its therapeutic use in the treatment of inflammatory pain in animals.

Phytochemicals for human disease: An update on plant-derived compounds antibacterial activity

In recent years, many studies have shown that phytochemicals exert their antibacterial activity through different mechanisms of action, such as damage to the bacterial membrane and suppression of virulence factors, including inhibition of the activity of enzymes and toxins, and bacterial biofilm formation. In this review, we summarise data from the available literature regarding the antibacterial effects of the main phytochemicals belonging to different chemical classes, alkaloids, sulfur-containing phytochemicals, terpenoids, and polyphenols. Some phytochemicals, besides having direct antimicrobial activity, showed an in vitro synergistic effect when tested in combination with conventional antibiotics, modifying antibiotic resistance. Review of the literature showed that phytochemicals represent a possible source of effective, cheap and safe antimicrobial agents, though much work must still be carried out, especially in in vivo conditions to ensure the selection of effective antimicrobial substances with low side and adverse effects.

Tanshinones and mental diseases: from chemistry to medicine

The prevalence of mental diseases, especially neurodegenerative disorders, is ever-increasing, while treatment options for such disorders are limited and insufficient. In this scarcity of available medication, it is a feasible strategy to search for potential drugs among natural compounds, such as those found in plants. One such plant source is the root of Chinese sage, Salvia miltiorrhiza Bunge (Labiatae), which contains several compounds reported to possess neuroprotective activities. The most important of these compounds are tanshinones, which have been reported to possess ameliorative activity against a myriad of mental diseases such as Alzheimer’s disease, cerebral ischemia/reperfusion injury, and glioma, along with promoting neuronal differentiation and manifesting antinociceptive and anticonvulsant outcomes. This review offers a critical evaluation of the utility of tanshinones to treat mental illnesses, and sheds light on the underlying mechanisms through which these naturally occurring compounds confer neuroprotection.

Is the plant-associated microbiota of Thymus spp. adapted to plant essential oil?

We examined whether the microbiota of two related aromatic thyme species, Thymus vulgaris and Thymus citriodorus, differs in relation to the composition of the respective essential oil (EO). A total of 576 bacterial isolates were obtained from three districts (leaves, roots and rhizospheric soil). They were taxonomically characterized and inspected for tolerance to the EO from the two thyme species. A district-related taxonomic pattern was found. In particular, high taxonomic diversity among the isolates from leaves was detected. Moreover, data obtained revealed a differential pattern of resistance of the isolates to EOs extracted from T. vulgaris and T. citriodorus, which was interpreted in terms of differing chemical composition of the EO of their respective host plants. In conclusion, we suggest that bacterial colonization of leaves in Thymus spp. is influenced by the EO present in leaf glandular tissue as one of the selective forces shaping endophytic community composition.

Pharmacological Effects of Capparis spinosa L

Medicinal plants have been known as one of the most important therapeutic agents since ancient times. During the last two decades, much attention has been paid to the health-promoting effects of edible medicinal plants, because of multiple beneficial effects and negligible adverse effects. Capparis spinosa L. is one of the most common medicinal plants, used widely in different parts of the world to treat numerous human diseases. This paper aims to critically review the available scientific literature regarding the health-promoting effects of C. spinosa, its traditional uses, cultivation protocols and phytochemical constituents. Recently, a wide range of evidence has shown that this plant possesses different biological effects, including antioxidant, anticancer and antibacterial effects. Phytochemical analysis shows that C. spinosa has high quantities of bioactive constituents, including polyphenolic compounds, which are responsible for its health-promoting effects, although many of these substances are present in low concentrations and significant changes in their content occur during processing. In addition, there is negligible scientific evidence regarding any adverse effects. Different health promotion activities, as well as tremendous diversity of active constituents, make C. spinosa a good candidate for discovering new drugs. However these findings are still in its infancy and future experimental and clinical studies are needed. Copyright © 2016 John Wiley & Sons, Ltd.

Evaluations of thyme extract effects in human normal bronchial and tracheal epithelial cell lines and in human lung cancer cell line

Thyme (Thymus vulgaris) is used traditionally to prepare herbal remedies possessing expectorant, mucolytic, antitussive and antispasmodic properties. The aim of the present study was to investigate the effects of a standardized hydroalcoholic extract of thyme on primary human airway (bronchial/tracheal) epithelial cell lines in a model of lung inflammation induced by LPS. In addition, the effects of thyme extract on human lung cancer cell line (H460) were analysed. Thyme extract showed significant anti-inflammatory properties by reducing the NF-κB p65 and NF-κB p52 transcription factors protein levels followed by the decrease of pro-inflammatory cytokines (IL-1 beta and IL-8), and Muc5ac secretion in human normal bronchial and tracheal epithelial cells. Moreover, the extract showed cytotoxic effects on H460 cancer cells, modulated the release of IL-1 beta, IL-8 and down-regulated NF-κB p65 and NF-κB p52 proteins. Taken together, these results substantiated the traditional uses of thyme in the treatment of respiratory diseases. Thyme extract might be an effective treatment of chronic diseases based on inflammatory processes when hypersecretion of mucus overwhelms the ciliary clearance and obstructs airways, causing morbidity and mortality. Moreover thyme extract, evaluated in H460 lung cancer cell line, demonstrated to induce cell cytotoxicity in addition to reduce inflammatory cell signals.

The Effect of Root, Shoot and Seed Extracts of The Iranian Thymus L. (Family: Lamiaceae) Species on HIV-1 Replication and CD4 Expression

Objective

The genus Thymus L. is a cushion plant that was previously used for the treatment of bronchitis and rheumatism. The present investigation was carried out to study the effects of root, shoot, leaf and seed extracts of five Thymus species and subspecies on peripheral blood mononuclear cells (PBMCs) toxicity and HIV-1 replication.

Materials and Methods

In this experimental study, the activity of the Thymus extracts on HIV-1 replication and lymphocytes population were examined respectively using HIV-1 p24 Antigen kit and flow-cytometer. The Thymus species effect was investigated, including Thymus kotschyanus, Thymus vulgaris, Thymus carmanicus, Thymus daenensis subspecies lancifolius and Thymus daenensis subspecies daenensis.

Results

The effect of root methanol extracts of all species on PBMCs proliferation was significantly higher than the other extracts. The intensity of CD4, CD3 and CD45 were decreased in the presence of all root extracts. Although the average median fluorescence intensity (MFI) values of CD19 were increased in the cells treated with these extracts. All methanol extracts showed anti-HIV-1 activity at high concentrations (200 and 500 µg/ml). Anti-HIV-1 activity of Thymus daenensis subspecies daenensis was significantly more than the other species.

Conclusion

These results demonstrated that root extracts of Thymus species might be a good candidate to investigate anti-HIV infection in vivo.

Extraction and Separation of Active Ingredients in Schisandra chinensis (Turcz.) Baill and the Study of their Antifungal Effects

Schisandra chinensis extracts (SEs) have traditionally been used as an oriental medicine for the treatment of various human diseases, however, their further application in the biocontrol of plant disease remains poorly understood. This study was conducted to develop eco-friendly botanical pesticides from extracts of S. chinensis and assess whether they could play a key role in plant disease defense. Concentrated active fractions (SE-I, SE-II, and SE-III) were obtained from S. chinensis via specific extraction and separation. Then, lignan-like substances, such as Schisanhenol B, were detected via High-Performance Liquid Chromatography-ElectroSpray Ionization-Mass Spectrometry (HPLC-ESI-MS) analyses of the active fractions. Moreover, the results from biological tests on colony growth inhibition and spore germination indicated that SE-I, SE-II, and SE-III could inhibit hyphal growth and spore generation of three important plant pathogenic fungi (Monilinia fructicola, Fusarium oxysporum, and Botryosphaeria dothidea). The study of the mechanisms of resistant fungi revealed that the oxidation resistance system, including reactive oxygen species (ROS), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD), was activated. The expression of genes related to defense, such as pathogenesis-related protein (PR4), α-farnesene synthase (AFS), polyphenol oxidase (PPO), and phenylalanine ammonia lyase (PAL) were shown to be up-regulated after treatment with SEs, which suggested an increase in apple immunity and that fruits were induced to effectively defend against the infection of pathogenic fungi (B. dothidea). This study revealed that SEs and their lignans represent promising resources for the development of safe, effective, and multi-targeted agents against pathogenic fungi.

Effect of Winemaking on the Composition of Red Wine as a Source of Polyphenols for Anti-Infective Biomaterials

Biomaterials releasing bactericides have currently become tools for thwarting medical device-associated infections. The ideal anti-infective biomaterial must counteract infection while safeguarding eukaryotic cell integrity. Red wine is a widely consumed beverage to which many biological properties are ascribed, including protective effects against oral infections and related bone (osteoarthritis, osteomyelitis, periprosthetic joint infections) and cardiovascular diseases. In this study, fifteen red wine samples derived from grapes native to the Oltrepò Pavese region (Italy), obtained from the winemaking processes of “Bonarda dell’Oltrepò Pavese” red wine, were analyzed alongside three samples obtained from marc pressing. Total polyphenol and monomeric anthocyanin contents were determined and metabolite profiling was conducted by means of a chromatographic analysis. Antibacterial activity of wine samples was evaluated against Streptococcus mutans, responsible for dental caries, Streptococcus salivarius, and Streptococcus pyogenes, two oral bacterial pathogens. Results highlighted the winemaking stages in which samples exhibit the highest content of polyphenols and the greatest antibacterial activity. Considering the global need for new weapons against bacterial infections and alternatives to conventional antibiotics, as well as the favorable bioactivities of polyphenols, results point to red wine as a source of antibacterial substances for developing new anti-infective biomaterials and coatings for biomedical devices.