Hematological and Hematopoietic Effects of Bactericidal Doses of Trans-Cinnamaldehyde and Thyme Oil on Cyprinus carpio Juveniles

The effects of two potential antibacterial agents of plant origin: trans-cinnamaldehyde (TC) and thyme oil (TO) on the peripheral blood parameters and cellular composition of hematopoietic tissue of Cyprinus carpio were studied. Both phytochemicals were used in the doses based on the bactericidal concentrations against Aeromonas spp. developed earlier in in vitro study. The fish were fed for 2 weeks on a commercial feed supplemented with 10 μl/kg of TC or 20 μl/kg of TO. Groups TC1 and TO1 were fed diets containing phytochemicals daily, while groups TC2 and TO2 every 2 days. Control group and groups TC2 and TO2 on the remaining days were fed plain feed. Peripheral blood and head kidney hematopoietic tissue were sampled from all the fish at the end of the experiment. In all the groups, hematological values were within the reference ranges for the healthy common carp juveniles. However, blood hemoglobin (Hb) concentration and mean corpuscular hemoglobin concentration (MCHC) were significantly lower in all the groups exposed to TC and TO, while MCH in TC1, TO1, and TO2 compared to the control. TC and TO did not affect leukocyte count [white blood cell (WBC)], differential leukocyte count, the oxidative activity of phagocytes [nitroblue tetrazolium (NBT)], or thrombocyte count (Thro). No significant alterations were observed in the hematopoietic tissue. The results showed that TC and TO exhibited no considerable hematotoxic effects and trials of their use in the treatment of fish infected with Aeromonas spp. may be undertaken.

Inhibitory effect of thyme oil as an antioxidant for waste cooking oil biodiesel crystallization

The effects of thyme oil extract as an antioxidant on crystallization properties of waste cooking oil biodiesel were investigated. The inhibitory effect was determined for ASTM D7545 standard method for biodiesel added with 1000, 2000, and 3000 ppm of additives by using oxifast device and compared with the chemical antioxidant butylated hydroxytoluene (BHT). Inhibition time data were determined by converting the oxidation stability analysis results. The crystallization temperatures (Tcr) of the samples were determined by using a Differential Scanning Calorimetry (DSC) technique. Tcr values of samples with antioxidants were decreased compared to the non-antioxidant biodiesel sample (B100). The order of antioxidant power was B100<B100T1<B100T2 = B100BHT1<B100BHT2<B100T3<B100BHT3. The solid fat content (SFC %) values were determined with different antioxidant concentrations versus different times. The minimum SFC % was determined in B100T3 and B100BHT3 in 3000 ppm antioxidant concentrations in 720 min. DSC results show that the crystallization onset temperatures for B100, B100T3, and B100BHT3 were −51.83 °C, −53.59 °C, and −54.15 °C, respectively. The kinetics of crystallization was determined and k and n values were calculated. The addition of thyme oil extract as a natural antioxidant has a positive effect on biodiesel oxidative stability for all concentrations.

Synthesis, Controlled Release, and Stability on Storage of Chitosan-Thyme Essential Oil Nanocapsules for Food Applications

The nanoencapsulation of thyme essential oil has been greatly important in food science, given its remarkable antioxidant and antimicrobial capacity. However, its analysis in storage has not been established in terms of physical stability, antioxidant capacity, and release studies. In this paper, chitosan-thyme oil nanocapsules were prepared by the ionic gelation method. These were characterized for differential calorimetry, release kinetic, and infrared spectroscopy. The chitosan-thyme oil nanocapsules were stored at 4 and 25 °C for 5 weeks, the changes in particle size, zeta potential, stability (diffuse reflectance), and antioxidant capacity were analyzed and associated with nanocapsules’ functionality. The results show that the storage time and temperature significantly modify the particle size (keeping the nano-size throughout the storage), the release of the bioactive was Fickian with t0.193 according to Korsmery & Peppas and best described by Higuchi model associated with changes in the zeta potential from 8 mV to −11 mV at 4 °C. The differential scanning calorimetry and infrared spectroscopy results confirm the good integration of the components. The antioxidant capacity revealed a direct relationship with residual oil concentration with a decrease in the ABTS test of 15% at 4 °C and 37% at 25 °C. The residual bioactive content was 77% at 4 °C and 62% at 25 °C, confirming nanoencapsulation effectiveness. The present investigation provides helpful information so that these systems can be applied in food conservation.

Influence of dietary protein levels and some cold pressed oil supplementations on productive and reproductive performance and egg quality of laying Japanese quail

The present study was carried out to examine the effect of dietary protein levels (18, 20, and 22%) and addition of cold-pressed oils (no addition, 1 g thyme, 1 g oregano, and 0.5 g thyme + 0.5 g oregano /kg diet) on the productive and reproductive performance and egg quality of Japanese quail at the laying period. 324 mature ten-week-old Japanese quails (216 females and 108 males) were used. Quails were randomly distributed to 12 treatment groups, 27 in each group, with 3 replicates of 9 quails (6 females and 3 males) per group. Feed conversion ratio (FCR) significantly improved in the layers fed with the diets containing 20 or 22% CP in all experimental periods, except in 3- to 4-month-old birds. The diets supplemented with thyme only or interaction with oregano improved FCR significantly compared to the control or oregano -administered group in all experimental periods, except in 2- to 3-month-old birds. Dietary supplementation with thyme oil caused the egg number and egg mass to increase significantly in all experimental periods compared to the other dietary groups. Fertility percentages were significantly higher in the groups which had oregano than in the control group. Dietary supplementation with thyme oil significantly increased the egg number (P<0.05) and egg mass (P<0.01) in all experimental periods compared to other dietary groups. Fertility and hatchability percentages were not significantly affected due to varying dietary protein levels throughout the experiment. In conclusion, the quails fed with a diet containing 20 to 22% CP or supplemented with oregano or thyme oil exhibited an improved productive and reproductive performance without any detrimental impacts on the other parameters studied.

Inhibitory effect of Garlic oil, Clove oil and Thyme oil on Micrococcus Luteus and Staphylococcus epidermidis.

This study is aimed to investigate the antimicrobial activity of Garlic, Thyme and Clove essential oils against Micrococcus luteus and Staphylococcus epidermidis. Using natural oils to fight the bacteria will limit the usage of antibiotics, reducing the probability of antibiotic resistance which is a global increasing problem. Also, it will eliminate antibiotic side-effects such as vomiting, diarrhoea and abdominal pain, Which occurs around 1 in 10 people (NHS, 2019). Antibiotics also have an effect the biofilm layer, causing a decrease in immunity. Micrococcus luteus has shown no growth in the trail run when the extracts where undiluted, nor in the main investigation when dilutions took place. This reveals the susceptibility of the bacteria to the following essential oils. Staphylococcus epidermidis has shown to be more resistant than micrococcus luteus. The oils however have produced a diameter of inhibition zone (DIZ), which means the oils are effective. Clove essential oil has produced the smallest inhibition zones in all concentrations carried out, suggesting that it’s the least effective extract. Thyme oil and clove oil have produced similar results; however, Thyme has shown a stronger antimicrobial effect at the 30 and 40% concentrations, whereas garlic has shown a stronger effect using the 20% concentration which has the highest coefficient of variation at 32.00% suggesting that it’s the least precise result. These results indicate that these essential oils have strong antimicrobial properties suggesting a potential clinical relevance in tackling bacteria.