Thymus Zygis Research Articles

Natural antioxidants in extruded fish feed: Protection at different storage temperatures

This study examines five different specifically designed extruded fish feeds: BD (basal diet), without added antioxidants; BHT, with 200mg/kg of butylhydroxytoluene; RO, with 600mg/kg of rosemary extract (Rosmarinus officinalis); TC, with 500mg/kg of thyme essential oil (Thymbra capitata, carvacrol chemotype); and TZ, with 500mg/kg of thyme essential oil (Thymus zygis, subspecies gracilis, thymol chemotype). The feeds were produced by means of a cooking-extrusion process and were stored under standard conditions at two different average temperatures, either refrigerated (4±1°C) or at ambient temperature (20–28°C). Samples were taken during processing (raw mix, recently extruded (moist) and dry feed) and at 4, 8, 12 and 24 weeks of storage. Both TBARS and induced TBARS were determined at each sampling point, as well as phenolic compounds content after feed processing. During the preparation process, the RO feed was the least oxidized and retained the least amount of phenols. The oxidative status of all feeds was maintained in cold storage, although the BD diet became less resistant to induced oxidation. At ambient temperature, the RO and BHT feeds showed the greatest protection against induced oxidation starting at week 8, and at the end of the storage period, the RO feed was the least oxidized. Overall, rosemary extract had a similar effect to that of butylhydroxytoluene on the processing and storage of extruded feed, and better than that of thyme essential oils.

Chemical composition and antibacterial activity of Thymus zygis subsp. gracilis (Boiss.) R. Morales essential oils from Morocco

Thymus zygis subsp. gracilis samples were collected from different Moroccan Middle Atlas sites at three phenological stages. Chemical composition of essential oils obtained from these samples was studied and their antimicrobial activity was evaluated. GC-MS analysis of essential oils shows quantitative and qualitative changes in the chemical profile. Twenty-three components were detected. These compounds fall under at least four chemical families whose relative importance varies with the sites and the phenological stages. Monoterpens were the most abundant and their percentage in essential oils varied from 61.38 to 94.91. Carvacrol (16.07 to 74.33%), thymol (1.47 to 32.46%), p-cymene (6.97 to 40.26%) and γ-terpinene (2.68 to 22%) were the main constituents. Bactericidal property of Thymus zygis essential oils was also evaluated in vitro against six strains of phytopathogenic bacteria. All bacterial strains tested were susceptible to essential oils. Maximum activity was observed against the Gram-negative bacterium Erwinia amylovora and Gram-positive actinomycete Streptomyces scabiei. The most bactericidal effect was observed against Streptomyces scabei. Its minimum bactericidal concentration (MBC) was 50 μg.mL-1 . At post-flowering stage, carvacrol chemical profile was the most efficient.

Supercritical fluid extraction as an alternative process to obtain antiviral agents from thyme species

The antiviral properties of supercritical CO2 extracts obtained from thyme species (Thymus vulgaris, Thymus hyemalis and Thymus zygis) were evaluated against the herpes simplex virus type 1 (HSV-1) at different stages during virus infection. Results indicated that when cells were pre-treated with the thyme extracts, an important reduction of virus infectivity was achieved; being T. zygis extract more effective than the other thyme species extracts. Comparing data obtained during the adsorption stage with those found in the pre-treatment step, at the same concentration, the reduction of the virus infectivity was increased by 30%, indicating that extracts were more effective when applied during adsorption period. Moreover, supercritical extracts of thyme species were able to significantly inhibit the in vitro virus replication, showing IC50 values among 1.74–2.25μg/mL. A GC–MS characterization of supercritical extracts was carried out in order to identify the type of compounds responsible for the antiviral activity. Thus, the higher antiviral activity found in T. zygis supercritical extract, could be related to the higher percentage of thymol, carvacrol and borneol (79.77%) presented in this extract.Supercritical fluid extraction represents an alternative method to obtain antiviral extracts from Thymus species. These supercritical extracts mainly inhibit HSV-1 intracellular replication, although they were also able to disrupt the virus attachment step.

Effect of feeding goats with distilled and non-distilled thyme leaves (Thymus zygis subp. gracilis) on milk and cheese properties

The aim of this study was to evaluate the effect of feeding goats with distilled and non-distilled thyme leaves (Thymus zygis subsp. gracilis) on the physicochemical composition and technological properties of pasteurised goat milk, and on the physicochemical composition, phenolic content, oxidative stability, microbiology, sensory and texture profile of Murcia al Vino goat cheese. One group of goats was fed the basal diet (control), the second and third groups were fed with different levels of distilled (10 and 20%) or non-distilled (3·75 and 7·5%) thyme leaves. Goat milk physicochemical composition was significantly affected by the substitution of 7·5% of basal goat diet with non-distilled thyme leaves (increase in fat, protein, dry matter and PUFA content), while goat milk clotting time was increased significantly by the introduction of 20% distilled thyme leaves, which reduces its technological suitability. Microbiology, sensory and texture profiles were not affected by the introduction of distilled thyme leaves. The introduction of distilled and non-distilled thyme leaves as an alternative feed to diet can lead to an inhibition of lipids oxidation. The introduction of distilled and non-distilled thyme leaves into goat's diet can be successfully adopted as a strategy to reduce feeding costs and to take advantage of the waste from the production of essential oils, minimising waste removing costs and the environmental impact.

Chemical composition and in vitro antibacterial properties of essential oils of four Thymus species from organic growth

In organic food industry no chemical additives can be used to prevent microbial spoilage. As a consequence, the essential oils (EOs) obtained from aromatic herbs and spices are gaining interest for their potential as preservatives. The EOs of Thymus zygis, Thymus mastichina, Thymus capitatus and Thymus vulgaris obtained from organic growth, were chemically analyzed and identified by GC and GC–MS, while the agar disk diffusion and microdilution assays were used to determine their antibacterial activity. In T. mastichina EO the major compound was 1,8-cineole (51.94%) whilst in T. zygis EO the main constituent was thymol (48.59%). T. capitatus EO was characterized by high content in carvacrol (69.83%). Finally, T. vulgaris EO had a high content of linaool (44.00%).The agar disk diffusion assay, T. zygis and T. capitatus EOs showed inhibitory effects against the ten tested bacteria, while T. matichina and T. vulgaris had inhibitory effects against eight and seven tested bacteria, respectively. T. zygis and T. capitatus EOs had higher inhibition halos against all tested bacteria, at higher concentration (40μL), than T. matichina and T. vulgaris EOs. The microdilution assay, T. mastichina EO had a MIC values ranging between 3.75 and 7.5μL/mL. Whilst in the case of T. zygis, T. capitatus and T. vulgaris EOs the MIC values ranged between 1.87 and 7.5μL/mL.

Short communication. Influence of phenological stage on the antioxidant activity of Thymus zygis s. l. essential oil

When a species has proven antioxidant capacity and possible commercial application it is important to know whether or not this activity varies with the phenological stage of the raw material commodity. The present work aims to assess this topic for the case of Thymus zygis s.l. We analyzed the yield and the chemical composition (gas chromatographymass spectrometry) of its essential oil in five wild populations from the Southwest of Iberian Peninsula at flowering and fruiting stage. We measured their TEAC (Trolox equivalent antioxidant activity) values. The main components were p-cymene (flowering: 33.6-16.2%; fruiting: 43.2-30.3%), γ-terpinene (flowering: 13.5-5.78%; fruiting: 4.67-1.96%) and thymol (flowering: 46.45-22.2%; fruiting: 54.24-13.9%); the latest, especially high (flowering: 46.45%; fruiting: 54.24%) in one of the populations, identified as Thymus zygis ssp. gracilis (Boiss.) R. Morales, which showed the highest antioxidant activity as well. In the set of samples TEAC oscillated between 16.12-30.52 mmol Trolox L-1 (flowering) and 10.96-40.24 mmol Trolox L-1 (fruiting). No significant differences between antioxidant activity of both stages were found, but yields were significantly higher at flowering time. These levels of antioxidant activity are close to those achieved as highly antioxidant food products, as coffee or wine. This species can be a good raw material for agribusiness use, specially the population of Thymus zygis ssp. gracilis.

Bioassay-guided fractionation of a thymol-deprived hydrophilic thyme extract and its antispasmodic effect

Ethnopharmacological relevanceExtracts from Thymus vulgaris L. and Thymus zygis L. are traditionally used for bronchitis, catarrhs of the respiratory tract and supportive treatment of pertussis. A potential spasmolytic effect is thought to be due to the presence of the monoterpenoid phenols thymol and carvacrol in the extract. Based on previous data the present investigation aimed to clarify if thymol-deprived thyme extracts (as been in use within German drug market) have antispasmodic activity. Additionally compounds responsible for this effect had to be identified. Materials and methodsThyme fluid extract was subsequently fractionated by FCPC, LPLC, and HPLC and compounds isolated were identified by spectroscopic methods. Bioassay testing was done by quantification of antispasmodic activity in the preconstricted rat smooth muscle trachea model against papaverin as positive control. ResultsThymol-deprived spissum extract (SE) had good antispasmodic activity (−37%, related to the maximum contraction). Bioassay-guided fractionation indicated that rosmarinic acid and apigenin do not contribute to this effect. Luteolin contributed significantly to the antispasmodic activity (−9%). ConclusionsThyme extracts have antispasmodic activity, which is at least due to synergistic effects of phenolic volatile oil compounds and the flavone luteolin. Specifications of thyme-containing preparations should refer to this flavone in addition to focusing on the volatile phenols.

Hypolipidemic and antioxidant effect of polyphenol-rich extracts from Moroccan thyme varieties

summary Background & aims: In the present study, the polyphenol-rich extracts of four endemic medicinal plants (Thymus satureioides, Thymus zygis L., Thymus atlanticus and Thymus vulgaris) widely used in the Errachidia area (south east of Morocco) were analyzed for their hypocholesterolemic, hypotriglyceridemic, and antioxidant activities. Methods: Hyperlipidemia was induced in rats by intraperitoneal injection of Triton WR-1339 at a dose of 200 mg/kg body weight. The animals were divided into seven groups: the normolipidemic control group (NCG), the hyperlipidemic control group (HCG), the T. atlanticus-treated group (TA), the T. zygis-treated group (TZ), the T. satureioides-treated group (TS), the T. vulgaris-treated group (TV) and the Fenofibratetreated group (FF). The hyperlipidemic groups were treated with herbal extracts at a dose of 0.2 g/100 g body weight and with fenofibrate at a dose of 6.5 mg/100 g body weight. The antioxidant activity of the polyphenol-rich extracts was assessed by using the Ferric Reducing Antioxidant Power assay (FRAP), the Radical Scavenging Activity method (RSA) and the inhibition of 2,2 0-azobis (2-amidinopropane) hydrochloride (AAPH) that induces oxidative erythrocyte hemolysis. Results: After 24 h of treatment with polyphenol-rich extract from T. atlanticus, plasma total cholesterol, triglycerides and LDL-cholesterol decreased by 82.8% (P < 0.001), 96.4% (P < 0.001) and 82.2% (P < 0.001), respectively. The results demonstrate that the four aqueous thyme extracts possess antioxidant activity as evidenced by ferric reducing/antioxidant activity (equivalent to 50.79 � 2.02 mmol Trolox/g of extract) and radical scavenging activity (IC50: 0.44 � 0.02 mg/mL of extract). Conclusion: Our findings suggest that polyphenol-rich thyme extracts might be considered for therapeutic use to treat atherosclerosis.

Bioclimatic influence on essential oil composition in South Iberian Peninsular populations of Thymus zygis

The variation in yield and essential oil composition of some plants of Thymus zygis was studied through their life cycle. The relationship between the concentration of the essential oils’ main compounds and the most frequently used bioclimatic indices was stated. Individual samples from seven populations growing wild in the South Iberian Peninsula were studied to assess the phenological variation of their oils. The samples showed a maximum yield at the flowering stage. The most representative compounds were selected, statistically analyzed and clustered in two groups, called thymol and γ-terpinene according to their behavior through the cycle of the plants studied.

Kinetic study of the supercritical CO2 extraction of different plants from Lamiaceae family

The supercritical CO2 extraction of four different plants from Lamiaceae family, namely oregano (Origanum vulgare), thyme (Thymus zygis), sage (Salvia officinalis) and rosemary (Rosmarinus officinalis) was carried out in an experimental pilot-plant comprising an extraction cell of 2L capacity. 600g of leaves of each plant material, with the same pre-treatment, were extracted at the same pressure and temperature (30MPa and 313K) and using 2.4kg/h of CO2. Further, the same fractionation procedure in a two on-line decompressing separators at, respectively, 10MPa and 0.1MPa was employed. In this way, a thoughtful comparison of the extraction kinetic was established and discussed, in terms of the extraction yields attained in the separators, the variation of the essential oil composition with time and the content of key bioactive substances identified in the different fractions.

Analyzing the community composition of arbuscular mycorrhizal fungi colonizing the roots of representative shrubland species in a Mediterranean ecosystem

Community composition of arbuscular mycorrhizal (AM) fungi was analyzed in the roots of five representative shrub species (Genista cinerea, Lavandula latifolia, Rosmarinus officinalis, Thymus mastichina and Thymus zygis) growing in a typical semi-arid Mediterranean ecosystem. Roots from a well-preserved area of the ecosystem were extracted from soil and analyzed by nested PCR, single strand conformation polymorphism and sequencing of the NS31-AM1 and NS8-ARCH1311 regions of the small subunit of the ribosomal DNA (SSU rDNA). Ten AM fungal phylotypes were identified; eight belonged to the Glomeraceae and two to the Diversisporaceae. Only two of the phylotypes clustered with sequences of morphologically defined species and a high dominance by one AM group (Glomus intraradices) was detected. Our diversity analyses revealed that the AM fungal communities of G. cinerea, L. latifolia and T. mastichina did not significantly differ while the AM fungal communities of R. officinalis and T. zygis were distant from this cluster and from each other. The highest diversity was found in the roots of T. zygis. Our data indicate that co-occurring plant species may house distinct communities of AM fungi.

Effects of Thyme Extract Oils (fromThymus vulgaris,Thymus zygis,andThymus hyemalis) on Cytokine Production and Gene Expression of oxLDL-Stimulated THP-1-Macrophages

Properties of thyme extracts from three different species (Thymus vulgaris, Thymus zygis, and Thymus hyemalis) were examined. Two oil fractions from each species were obtained by CO2 supercritical fluid extraction. Main compounds presented in the supercritical extracts of the three thyme varieties were 1,8 cineole, thymol, camphor, borneol, and carvacrol. As a cellular model of inflammation/atherogenesis, we use human macrophages derived from THP-1 monocytes and activated by oxidized LDLs. These cells were incubated with the thyme fraction oils, and the productions and gene expressions of the inflammatory mediators TNF-α, IL-1B, IL-6, and IL-10 were determined. Thyme extracts significantly reduced production and gene expression of the proinflammatory mediators TNF-α, IL-1B, and IL-6 and highly increased these parameters on the anti-inflammatory IL-10 cytokine. Changes on production and gene expressions were dose dependent and according to the thyme content of each species. Taken together, these results may suggest that thyme extracts could have anti-inflammatory effects.

The effect of diets supplemented with thyme essential oils and rosemary extract on the deterioration of farmed gilthead seabream (Sparus aurata) during storage on ice

The effect on quality were assessed for gilthead seabream fed five different diets: control (basal diet); BHT (basal diet with 200mgkg−1 of butylated hydroxytoluene); rosemary (basal diet with 600mgkg−1 of rosemary extract –Rosmarinus officinalis); carvacrol (basal diet with 500mgkg−1 of essential oil of Thymbra capitata, carvacrol chemotype); and thymol (basal diet with 500mgg−1 of essential oil of Thymus zygis, subspecies gracilis, thymol chemotype). After 18weeks of experimentation, the animals were stored on ice at 4°C for 0, 7, 14, and 21days. Physical–chemical, microbiological and sensory analyses were carried out at each sampling point to determine the degree of deterioration in the gilthead seabream. Lower indices of oxidation were observed in animals who were administered feeds supplemented with BHT, carvacrol and (to a lesser degree) rosemary. Lower bacteria counts were observed for the BHT and thymol groups, in addition to a slower deterioration in terms of sensory perception. Accordingly, the addition of natural antioxidants to the diet may have an added effect on fish quality, delaying post mortem deterioration.

Temporal dynamics of arbuscular mycorrhizal fungi colonizing roots of representative shrub species in a semi-arid Mediterranean ecosystem

Arbuscular mycorrhizal (AM) symbiosis plays an important role in improving plant fitness and soil quality, particularly in fragile and stressed environments, as those in certain areas of Mediterranean ecosystems. AM fungal communities are usually affected by dynamic factors such as the plant community structure and composition, which in turn are imposed by seasonality. For this reason, a one-year-round time-course trial was performed by sampling the root system of two representative shrubland species (Rosmarinus officinalis and Thymus zygis) within a typical Mediterranean ecosystem from the Southeast of Spain. The 18S rDNA gene, of the AM fungal community in roots, was subjected to PCR-SSCP, sequencing, and phylogenetic analysis. Forty-three different AM fungal sequence types were found which clustered in 16 phylotypes: 14 belonged to the Glomeraceae and two to the Diversisporaceae. Surprisingly, only two of these phylotypes were related with sequences of morphologically defined species: Glomus intraradices and Glomus constrictum. Significant differences were detected for the relative abundance of some phylotypes while no effects were found for the calculated diversity indices. These results may help to design efficient mycorrhizal-based revegetation programs for this type of ecosystems.

Efeito de diferentes misturas de substratos orgânicos na biomassa e no óleo essencial de Thymus zygis

In this trial we evaluated the effect of different mixtures of organic growing media substratum and vermicompost and their physical properties on biomass, chemical composition and yield of essential oils of Thymus zygis. Five treatments were established based on two types of organic materials (O, commercial growing media, and V, vermicompost). The following proportions were studied (v/v): V100 (100%V); VO75-25 (75%V+25%O); VO50-50 (50%V+50%O); VO 25-75 (25%V+75%O) and O100 (100%O). The inclusion of vermicompost did not improve biomass production. The treatment O100 produced more biomass and the lowest was obtained in VO25-75. On V100 treatment all plants were dead and also have showed the highest pH and particle density and conversely presented the lowest value of total pore space. Oxygenated monoterpenes predominated in the oils extracted from plants in O100 and VO25-75, contrary to what was found for non-oxygenated monoterpenes having these prevailed in VO75-25 and VO50-50. The concentration of thymol was high in the mixtures tested, particularly in VO25-75.

Composition chimique, activité antimicrobiennne et antioxydante de l’huile essentielle de Thymus zygis du Maroc

This work studies the chemical composition, antioxidant and antimicrobial activity of the essential oils of Thymus zygis of Morocco against four bacteria, three fungi and four wood-decay fungi. The chromatographic analysis (GC/FID and GC/MS) showed that the essential oils of Thymus zygis is characterized by the presence of thymol (33.02%), o-cymene (32.02%) and β-E-ocimene (11.90%) along with other compounds at relatively low levels: linalool (3.99%), carvacrol (2.69%), β-pinene (2.08%), borneol (1.56%), E-caryophyllene (1.51%), 1,4-cineole (1.49%) and tricyclene (1.34%). The antioxidant activity determined by the DPPH test showd that the essential oils has a high antioxidant potential with IC 50 = 75.97±0.86 μg/ml, compared to others species of thyme in the literature. At the concentrations studied, the essence showed a strong antibacterial and antifungal activity. This bioactivity is due mainly to the richness of this species in thymol known for its effectiveness against microbial agents.

Effect of supplementing ewes’ diet with thyme ( Thymus zygis ssp. gracilis) leaves on the lipid oxidation of cooked lamb meat

The aim of this study was to ascertain whether the inclusion of thyme leaves in the diet of pregnant sheep affects the sensorial characteristics and oxidative stability of cooked lamb meat. Thirty-six Segureña sheeps were randomly assigned into three homogeneous groups. One group was fed a basal diet as control, while the diet of the other two groups was modified by substituting 3.75% and 7.5% of the control diet with thyme leaves. TBARS, volatile compounds, and the sensory characteristics of cooked lamb meat were analysed on days 0, 2 and 4. The incorporation of thyme into the animal diet favoured the antioxidant capacity of these cooked lamb meat samples. The cooked meat of lambs from ewes fed thyme leaves showed lower TBARS, hexanal values, rancid odour and rancid flavour scores. No statistically significant differences were detected between the results obtained for the two leaf levels.

Chemical, antifungal and cytotoxic evaluation of the essential oil of Thymus zygis subsp. sylvestris

Several Thymus species are used since olden times in traditional medicine, due to recognized therapeutic properties, namely the antimicrobial activity of their essential oils. In the present study we evaluated the composition and the antifungal activity (MIC and MLC) of four type oils obtained from Thymus zygis subsp. sylvestris, an Iberian endemic Lamiaceae, against yeasts, dermatophyte and Aspergillus strains. Moreover, we also assessed their cytotoxicity in skin dendritic cells at concentrations showing significant antifungal activity. The oils were investigated by GC and GC–MS, and four chemotypes were characterized: carvacrol (25.0%), thymol (23.8%), geranyl acetate/geraniol (20.8% and 19.8%) and linalool (30.0%). Assessment of cell viability was made by the MTT assay, and the results demonstrated that the oil with high amounts of carvacrol, which have stronger antifungal activity against dermatophyte strains, showed no cytotoxic effect, at concentrations ranging from 0.08 to 0.16 μL/mL, for as long as 24 h. In conclusion, it is possible to find appropriate doses of carvacrol type oil of T. zygis subsp sylvestris showing both antifungal activity and very low detrimental effect on mammalian cells. T. zygis with high content of carvacrol, could become a source of biologically active compounds for pharmaceutical industry.

Anti-Giardia activity of phenolic-rich essential oils: effects of Thymbra capitata, Origanum virens, Thymus zygis subsp. sylvestris, and Lippia graveolens on trophozoites growth, viability, adherence, and ultrastructure

The present work evaluates the anti-Giardia activity of phenolic-rich essential oils obtained from Thymbra capitata, Origanum virens, Thymus zygis subsp. sylvestris chemotype thymol, and Lippia graveolens aromatic plants. The effects were evaluated on parasite growth, cell viability adherence, and morphology. The tested essential oils inhibited the growth of Giardia lamblia. T. capitata essential oil is the most active followed by O. virens, T. zygis subsp. sylvestris, and L. graveolens oils. The tested essential oils at IC50 (71-257) microg/ml inhibited parasite adherence (p < 0.001) since the first hour of incubation and were able to kill almost 50% of the parasites population in a time-dependent manner. The main ultrastructural alterations promoted by essential oils were deformations in typical trophozoite appearance, often roundly shape, irregular dorsal and ventral surface, presence of membrane blebs, electrodense precipitates in cytoplasm and nuclei, and internalization of flagella and ventral disc. Our data suggest that essential oils induced cell death probably by processes associated to the loss of osmoregulation caused by plasmatic membrane alterations. Experiments revealed that the essential oils did not present cytotoxic effects in mammalian cells. In conclusion, T. capitata, O. virens, T. zygis subsp. sylvestris chemotype thymol, and L. graveolens essential oils have antigiardial activity in vitro and seem to have potential for the treatment of the parasitic disease caused by the protozoan G. lamblia.

Pérdida de suelo, fósforo y materia orgánica por erosión hídrica en parcelas revegetadas con matorral autóctono bajo clima semiárido

Two treatments with shrubs (Atriplex halimus (Ah) and Thymus Zygis (Tz)) were tested on hillsides from central Spain. It was studied the erosion and diffuse contamination by analyzing organic matter content (OM) and phosphorus (P2O5) in soil and sediments. Compared with the control treatment, Ah presented a significant decrease of runoff and erosion, 47% and 24% lower respectively, but Tz showed 12% more runoff and 152% more erosion than control. Enrichment ratios of OM and P2O5 are evident in eroded sedi­ment and also a strong relation between erosion and OM and P2O5 content was found, showing regression equations with high correlation coefficients, R=0.87 and 0.91 respectively.