Effect Of Thyme Essential Oils Research Articles

Effect of thyme essential oil on rumen parameters, nutrient digestibility, and nitrogen balance in wethers fed high concentrate diets

ABSTRACT This trial aimed to evaluate the effects of thyme essential oils (EO) on rumen parameters, nutrient digestibility and nitrogen balance in wethers fed with high-concentrate diet. Twenty rumen-cannulated wethers were blocked according to body weight (BW= 64.0±2.1kg), and received one of the following treatments: 25mg of monensin/kg of dry matter (DM; MON) or doses of thyme EO (1.25, 2.50 or 3.75g/kg of DM). The diet was composed of 90% concentrate. Thyme EO was composed mainly by thymol (46.6% of DM) and p-cymene (38.9% of DM). The nutrient intake and apparent digestibility were similar among treatments. The inclusion of 3.75g of thyme EO tended (P= 0.07) to increase butyrate compared to MON and 1.25OE and wethers fed with 1.25g of thyme EO tended (P= 0.07) to decrease ruminal pH on the 14th day compared to MON. The treatments did not affect acetate:propionate ratio, total short chain fatty acids (SCFA) and nitrogen retention. Results from this study suggest that adding thyme EO to high-concentrate diets may be used as an alternative to monensin as feed additive in feedlot lambs.

Antifungal and Virulence-Modulating Effects of Thyme Essential Oil against Fusarium spp., Causing Wheat Diseases

Wheat (Triticum aestivum L.) is one of the important cereals and a major source of human food worldwide. Fusarium pseudograminearum and F. culmorum are the causal agents of important diseases on wheat, including head scab, crown and root rot. Control of Fusarium diseases on wheat is very difficult and important because of not only no complete resistance in any wheat cultivar and long-term survival of the soil-borne pathogen, but also production of carcinogenic mycotoxins in wheat tissues, which are harmful for consumers. Nowadays, to avoid the ecological and environmental damage caused by chemical pesticides and fungicides, there is a great interest to use essential oils as plant-protective agents. Therefore, the aim of this study was to find an alternative to synthetic fungicides currently used in the control of these destructive wheat diseases. We investigated the antifungal activities of the essential oils obtained from 4 different plant species and the Thyme (Thymus vulgaris) essential oil (TEO) revealed the highest level of antifungal effect against two mentioned phytopathogens. Contact and volatile phase effects of different concentrations of TEO were found to inhibit the growth of both fungi. Spore germination and production were also strongly inhibited by the TEO. Light microscope scanning of vegetative growth of the fungi revealed destructive changes in the hyphae. The TEO, also showed a high seed protection capability against fungal infection with no negative effect on seed germination. In the in-vivo assay, which was performed under greenhouse conditions using susceptible wheat plans treated with the TEO, significant plant protection was observed against the pathogens. Investigating effect of the main components of the TEO revealed that cymene had the highest effect in decreasing both disease incidence (DI) and disease severity index (DSI) on wheat plants inoculated by Fusarium species. Therefore, the TEO and its ingredients could be used as environmentally friendly biofungicides in the protection of wheat plants against these Fusarium species. To our knowledge, this is the first report on the in vivo and in vitro inhibitory effects of the TEO and cymene, as its main ingredient, against destructive Fusarium spp. pathogenic on wheat.

Effects of thyme essential oil and A, C, and E vitamin combinations to diets on performance, egg quality, MDA, and 8-OHdG of laying hens under heat stress

ABSTRACT This experiment was conducted to evaluate the effects of supplementary thyme (Thymus vulgaris) essential oil (TEO) and A, C, and E vitamins on performance, egg quality and some biochemical parameters of laying hens under heat stress (HS). A total of 120 White Leghorn laying hens were randomly distributed into 5 experimental groups with 6 replicates and each replicate had 4 laying hens. The HS group was housed at 34°C between 08:00 am and 05:00 pm and the rest of the day at 22°C. The experimental groups were; 1: HS group; 2: HS + TEO (300 mg/kg TEO in diet), 3: HS + TEO + Vit-C (300 mg/kg TEO + 250 mg/kg vitamin C in diet), 4: HS + TEO + Vit-E (300 mg/kg TEO + 250 mg/kg vitamin E in diet), and 5: HS + TEO + Vit-A (300 mg/kg TEO + 15,000 IU/kg vit-A in diet). In the study, body weight, egg weight, feed intake and egg quality of the hens were not affected with treatment groups. Serum glucose level was decreased in the TEO group, plasma MDA was decreased in the TEO and TEO + Vit-C groups and 8-OHdG was decreased in the TEO + Vit-E. It was concluded that it would be more beneficial to use TEO against HS in laying hens with Vit-E and Vit-C instead of using it alone.

Cellular, physiological and molecular approaches to investigate the antifungal and anti-aflatoxigenic effects of thyme essential oil on Aspergillus flavus

Several approaches, including the detection of apoptotic-like cell death, aflatoxin B1 (AFB1) production and gene expression analysis, were carried out to provide insights into the antifungal and anti-aflatoxigenic effects of thyme essential oil (EO) on Aspergillus flavus. At 0.5 µL mL−1, thyme EO completely inhibited A. flavus growth. Furthermore, this antifungal activity triggered significant apoptosis, via nuclear condensation (87.5% of nuclei analyzed) and plasma membrane damage (in 100% of treated hyphae). Further analysis of AFB1 production and gene expression related to secondary metabolism (laeA) and the mechanism of virulence (lipA and meT) of A. flavus in the presence of thyme EO indicated important physiological changes related to its anti-aflatoxigenic property. These results highlight the potent antifungal abilities of thyme EO in controlling A. flavus and AFB1 production, especially the abilities that operate by exerting changes at the molecular level and inducing significant apoptotic-like cell death.

WPI and Cellulose Nanofibres Bio-nanocomposites: Effect of Thyme Essential Oil on the Morphological, Mechanical, Barrier and Optical Properties

The uncertainty of consumers about the toxicological effects of synthetic antioxidants incorporated into the packaging has led to a demand for natural substituents that exhibit antioxidant activity without adding risk to the consumers. In this context, the effects of adding different concentrations of thyme essential oil (TEO) (20, 30, and 40% w/w) to whey protein isolate (WPI) and cellulose nanofibre (CNF) bio-nanocomposites developed by casting were studied. Scanning electron microscopy showed a reduction in the dispersion of CNF's in all films with the addition of TEO. The addition of TEO also decreased the water vapor permeability, increased the glass transition temperature, and crystallinity index. For the mechanical properties, the addition of TEO produced less rigid and elastic films with decreased in tensile strength, elongation at break, puncture strength, puncture deformation, and elastic modulus. In addition, the mechanical properties showed the formation of non-interactive systems and the FTIR spectra showed maintenance of the phenolic compounds of the TEO after the synthesis of the films. The optical properties showed that films were less yellow (b*) with a tendency to green (a*), less saturated (c*), and less transparent when compared with the control (0% TEO). The addition of TEO to bio-nanocomposites of WPI and CNFs, in the concentration range tested, enabled the formation of materials with properties that encourage the studies for various applications.

Histopathological and Biochemical Effects of Thyme Essential Oil on H2O2 Stress in Heart Tissues

Thymus algeriensis (T. algeriensis) is traditionally used in Tunisia to treat many human diseases. The aim of the present study was to investigate whether terpenes extracted from the aerial parts of T. algeriensis are potent cardioprotective agents for hydrogen peroxide (H2O2)-induced cardiotoxicity in rats. Thirty (30) rats were divided into six groups as per the experimental design: control (n = 6); 0.1 mmol/L H2O2 (LD H2O2) (n = 6); 1 mmol/L H2O2 (HD H2O2) (n = 6); oily fraction of T. algeriensis (OFTS) (180 mg/kg b.wt) (n = 6); OFTS + 0.1 mmol/L H2O2 (n = 6); and OFTS + 1 mmol/L H2O2 (n = 6). The H2O2 demonstrated concentration-dependent cardiotoxic effects in vitro. While, exposure of rats to OFTS significantly depleted H2O2-induced protein oxidation and lipid peroxidation, it raised antioxidant defence enzymes, and protected against H2O2-induced histopathological alterations. The antioxidant potential of the thyme essence was assessed by both enzymatic and non-enzymatic antioxidants. In conclusion, OFTS may be a potential compound for the therapy of oxidative stress-induced heart disease.

Regional effect on essential oil composition and antimicrobial activity of Thymus capitatus L.

ABSTRACTA biochemical characterization and a geographic variability of Thymus capitatus L. essential oils were undertaken. Chromatographic analysis using gas chromatography-flame ionization detector and gas chromatography-mass spectrometry of essential oils extracted from thyme aerial parts from four Tunisian regions (Kef, Bizerte, Boukornine and Grombalia) showed the predominance of carvacrol (75.79 ± 2.07%) in Boukornine region, thyme essential oils being carvacrol chemotype. Obtained results of antimicrobial activities showed that thyme essential oil has important antibacterial activity which was strongly related to the organoleptic quality of the oil which appeared strongly region-dependent. The inhibitory effect of thyme essential oils on the bacteria and fungi development showed that Bacillus cereus and Fusarium solani were the most sensitive bacteria and fungi, respectively. From these results, we have concluded that thyme essential oil could be used to cure mycotic infections and may have role as pharmaceutical and preservative agents.

Effect of thyme essential oil against Bacillus cereus planktonic growth and biofilm formation.

The objective of this study was to determine the effect of thyme essential oil (TEO) on the planktonic growth and biofilm formation of Bacillus cereus (B. cereus). GC-MS analysis of TEO allowed the detection of 13 compounds, and the major constituents were p-cymene (29.7%), thymol (23.73%), γ-terpinene (16.21%), and 1,8-cineole (9.74%). TEO exhibited a minimum inhibitory concentration (MIC) value against planktonic B. cereus of 0.25mg/mL. The potent effect of TEO to inhibit the growth of planktonic B. cereus was due to cell membrane damage, as evidenced by reduced cell viability, protein changes, decreased intracellular ATP concentration, increased extracellular ATP concentration and cell membrane depolarization, and cellular morphological changes. In addition, TEO exerted a significant inhibitory effect on B. cereus biofilm formation, as confirmed by environmental scanning electron microscopic images. These findings suggested that TEO has the potential to be developed as a natural food additive to control foodborne contamination associated with B. cereus and its biofilm.

The effect of thyme essential oil on germination and early growth of wheat

Essential oils (EOs) are becoming an important alternative as seed decontaminating agents opposite to synthetic seed preservatives due to their antimicrobial activities. They also inhibit seed germination which may be problematic for seeds of cultural plants. In the present study, different treatments of wheat (Triticum aestivum) grain with thyme (Thymus serpyllum) EO were tested. Wheat grains were treated with thyme EO for 6, 12 and 24 hours to determine the optimal time of EO treatment in order to reduce fungal infection of the grain surface and at the same time preserve high germination rate of seeds and good physiological status of seedlings during early stages of their growth. Germination rate, fresh mass and length of shoots and roots, and physiological status of the seedlings were compared according to the duration of the treatment. The 6 h-EO treatment was the most optimal procedure that did not affect seed germination, was not harmful for the seedlings and prevented fungal infections. The thyme EO could potentially be used as a protective agent for wheat grain intended for sowing and food production.

Altered Antimicrobial and Anti-biofilm Forming Effect of Thyme Essential Oil due to Changes in Composition

The antimicrobial and anti-biofilm forming effect of thyme (Thymus vulgaris) essential oil (TEO) with different compositions was evaluated. Normally the main component in this TEO is thymol, but in 2014 we found that the proportions of γ-terpinene and p-cymene (the precursors in thymol biosynthesis) increased and that of thymol decreased. This altered composition led to changes in the antimicrobial and anti-biofilm forming capacity of the essential oil depending also on the type of microorganisms. In the case of bacteria, minimal inhibitory (MIC) and minimal bactericidal (MBC) concentrations either decreased or increased. In the case of yeasts, minimal fungicidal concentrations (MFC) increased 4- and 8-fold for TEO containing p-cymene as the main component. On the contrary, MIC values decreased for all the tested moulds. Anti-biofilm forming activity of TEO containing p-cymene as its main component decreased in almost all cases and P. fluorescens biofilm forming capacity was even enhanced.

Bacteriological evaluation of minced meat with special reference to effect of thyme essential oil on it

Bacteriological evaluation of minced meat with special reference to effect of thyme essential oil on it

Synergistic antifungal effects of thyme essential oil and Lactobacillus plantarum cell-free supernatant against Penicillium spp. and in situ effects

This study evaluates the synergistic antifungal effects between thyme essential oils and Lactobacillus plantarum cell-free supernatant (LCFS) against Penicillium spp. and in situ antifungal activity in rice grains. Thyme essential oil and LCFS showed remarkable antifungal activities against Penicillium spp. with the minimum inhibitory concentration (MIC) of 40 and 80 µL/mL, respectively. The analysis of fractional inhibitory concentration (FIC) index showed the antifungal synergism between thyme essential oil and LCFS against Penicillium spp. with FIC index of 0.5. This synergism also resulted in fourfold reduction in their MICs when applied in combination. The antifungal modes of action were characterized by observing the changes in cell membrane permeability and degradation of fungal cell wall. The combination of thyme essential oil and LCFS (2 × MIC of each) showed remarkable in situ antifungal effect and completely inhibit the growth of Penicillium in rice seeds. The results suggested the possible applications of the observed synergism on actual crops. Practical applications Essential oils are used as preservative in food industry and high concentration of essential oil is associated with negative organoleptic characteristics. This study presented a novel approach for synergistic antifungal effects by using the combination of thyme essential oil and Lactobacillus plantarum cell-free supernatant (LCFS) against Penicillium spp. and systematic evaluation of the antifungal effect by using fractional inhibitory concentration (FIC) index method. This approach will be a role model for future research on synergism and overcome the major drawbacks of using live bacteria and the negative effects arising from antimicrobial activities of essential oils.

Effect of thyme essential oil and Lactococcus lactis CBM21 on the microbiota composition and quality of minimally processed lamb’s lettuce

The main aim of this work was to evaluate, at pilot scale in an industrial environment, the effects of the biocontrol agent Lactococcus lactis CBM21 and thyme essential oil compared to chlorine, used in the washing step of fresh-cut lamb’s lettuce, on the microbiota and its changes in relation to the time of storage. The modification of the microbial population was studied through pyrosequencing in addition to the traditional plate counts. In addition, the volatile molecule and sensory profiles were evaluated during the storage. The results showed no significant differences in terms of total aerobic mesophilic cell loads in relation to the washing solution adopted. However, the pyrosequencing data permitted to identify the genera and species able to dominate the spoilage associations over storage in relation to the treatment applied. Also, the analyses of the volatile molecule profiles of the samples during storage allowed the identification of specific molecules as markers of the spoilage for each different treatment. The sensory analyses after 3 and 5 days of storage showed the preference of the panelists for samples washed with the combination thyme EO and the biocontrol agent. These samples were preferred for attributes such as flavor, acceptability and overall quality. These results highlighted the effect of the innovative washing solutions on the quality of lettuce through the shift of microbiota towards genera and species with lower potential in decreasing the sensory properties of the product.

The Effect of Thyme Essential Oil (Thymus Vulgaris) Added to Quail Diets on Performance, Some Blood Parameters, and the Antioxidative Metabolism of the Serum and Liver Tissues

ABSTRACT This study was conducted to determine the effect of diets containing different levels of thyme essential oil (TEO) on performance, some serum parameters and the antioxidative metabolism of the serum and liver tissues in quails. A total number of 200 sixteen-days-old Japanese quails ( Coturnix coturnix japonica ) were used in the study. The animals were divided into 4 groups; the control group was fed only basal diet but groups TEO1, TEO2 and TEO3 had thyme essential oil of 150, 300 and 450 mg/kg, respectively, added to their diets. Body weight and daily weight gain increased with higher levels of thyme essential oil in the feed, yet a statistically significant increase was detected in only group TEO3 (p<0.05). Furthermore, in all of the groups that were fed on TEO, feed intake was significantly higher than that of the control group (p<0.05). In the groups that received thyme essential oil, serum creatinine and low-density lipoprotein (LDL) levels were low, whereas serum magnesium levels were high (p<0.05). Thyme essential oil significantly increased in liver catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and serum CAT and GSH-Px activities, and significantly reduced both liver and serum lipid peroxidation (malondialdehyde=MDA) levels (p<0.01). In result, while thyme essential oil partially affected the performance and serum parameters, it had a marked effect on the antioxidant metabolism.

Multiple response optimization of the effect of thyme essential oil against Listeria monocytogenes in ground meat at different times and temperatures

Response surface methodology was used to optimize conditions (e.g., Thyme oil concentration [0.0–0.57%] and storage temperature [0.0-14.14ºC]) for inhibiting the growth of L. monocytogenes (log cfu/g) in ground meat. Additionally, the effect of the variables; namely, temperature and concentration on µmax (maximum specific growth rate, ln cfu/g/h) values was also evaluated using a proposed combined model. The best fitting second order polynomial models were developed for each response using multiple linear regression analysis with backward elimination regression (BER) procedure. In this paper, multi-response surfaces using desirability function approaches were successfully applied to determine optimum operating conditions. Under these optimum treatment and storage parameters, L. monocytogenes populations at hours 6, 24, 48, 72 and 96 were 6.12, 5.96, 5.88, 5.81 and 5.41 log cfu/g and 0.001 ln cfu/g/h, respectively and μmax value 0.001 ln cfu/g/h. At the end, the proposed combined model is described numerically and experimentally.

Antioxidant Effect of Thyme Essential Oil on Oxidative Stability of Chicken Nuggets

Antioxidant Effect of Thyme Essential Oil on Oxidative Stability of Chicken Nuggets

Study of the dose of thyme essential oil in feed to prolong the shelf life of gilthead seabream (Sparus aurata)

The effect of thyme essential oil (Thymus zygis, subspecies gracilis) on the quality and shelf life of gilthead seabream was studied, when added to the diet: a control diet and four experimental diets (T500, T1000, T1500, T2000) with 500, 1000, 1500 and 2000 mg kg−1 of thyme essential oil, respectively. After 12 weeks of experimentation, the fish were stored on ice at 4 °C for 0, 7, 14 and 21 days. Physical–chemical, microbiological and sensory analyses were carried out at each sampling point to determine the degree of deterioration. A dose-dependent effect was observed on the colour, TBARS and total volatile basic nitrogen during the storage. Microbiological counts were lower for Enterobacteriaceae and coliforms at high doses of the essential oil. The sensory analysis showed an effect on the quality index that was not dependent on the dose, which extended the shelf life of gilthead seabream from 17 to 18 days for all doses.

Effect of thyme/cumin essential oils and butylated hydroxyl anisole/butylated hydroxyl toluene on physicochemical properties and oxidative/microbial stability of chicken patties

In this study, effects of thyme/cumin essential oils (EO) and butylated hydroxyl anisole (BHA)/butylated hydroxyl toluene (BHT) on physicochemical properties and storage stability of chicken patties were compared in different storage periods (0, 3, 7, 14, 21, and 28 d). It was found that there were significant (P < 0.05) differences between physicochemical properties of patty samples treated with EO and the synthetic antioxidants. The EO showed similar performance to those of BHA and BHT in limiting TBARS values of chicken patty samples. Similarity in performance was also the case for microbial stability (total aerobic mesophilic, psychrotrophic, lactic acid, and coliform bacteria as well as molds and yeasts); namely, their effects were significant (P < 0.05). Effect of thyme EO was significant (P < 0.05) and remarkable, not allowing any coliform bacteria to grow in the samples. Given that EO were obtained from natural sources, the data suggested that the EO might be more useful than their synthetic counterparts, BHA and BHT, as additives for chicken patties to maintain oxidative/microbial stability and increase shelf life.

Effect of thyme essential oil and selenium on intestine integrity and antioxidant status of broilers

1. This study evaluated the duodenal wall integrity, antioxidant status as well as some immunological parameters of broiler chickens supplemented with 0.5 g Thymus vulgaris essential oil (EO)/kg diet and 0.4 mg Se/kg DM (dry matter) derived from sodium selenite.2. A total of 192 one-d-old randomly divided chickens of both sexes (Ross 308 hybrid broilers) were divided into 4 treatment groups of 48 birds each.3. The first group was fed on a nutritionally balanced basal diet (BD). The other three groups received BD supplemented with 0.5 g/kg thyme oil, or 0.4 mg Se/kg DM, or both feed additives together.4. The results for the evaluated feed additives were (1) thyme oil – decreased malondialdehyde (MDA) concentration in duodenal mucosa and kidney, increased immunoglobulin A (IgA) concentration in duodenal mucosa, stimulated phagocytic activity in blood, improved intestinal barrier integrity (2) selenium – increased glutathione peroxidase (GPx) activity in blood and liver as well as thioredoxin reductase (TrxR) activity in duodenal mucosa, liver and in the kidney, (3) EO with selenium – increased thioredoxin reductase (TrxR) activity in duodenal mucosa.5. These results demonstrated that thyme oil alone showed more effective potential to improve intestinal barrier integrity and antioxidant status as well as evoking an immune response in chickens, than if diets were supplemented with both thyme oil and selenium.

Effects of Thyme Essential Oil on Performance, Some Blood Parameters and Ileal Microflora of Japanese Quail

The ban on the use of antibiotics as growth promoters has stimulated the search for alternative feed supplements in poultry production. The active principles of thyme essential oil act as a digestibility enhancer, balancing the gut microbial ecosystem and stimulating the secretion of endogenous digestive enzymes and thus improving growth performance in poultry (Lovkova et al., 2001; Williams and Losa, 2001). A study was performed to investigate the effects of thyme essential oil (TEO) on performance, carcass characteristics, some blood parameters and ileal microflora of Japanese quail. This study lasted 35 days of age. One hundred and fifty day-old male Japanese quail chicks in a completely randomized design with two treatments (with or without 1 g/kg TEO) and five replicates of 15 birds each were used. All parameters were measured at the end of the experiment. The supplementation of TEO significantly (P<0.05) increased live body weight and relative weights of carcass and breast, lowered serum triglyceride, total cholesterol and glucose and improved ileal microflora. It was concluded that the addition of 1 g/kg TEO might offer some beneficial effects on Japanese quail to increase live body weight and improve some blood parameters and gut miroflora.