EO Concentration Research Articles

Maintenance of postharvest quality of ‘Palmer’ mango coated with biodegradable coatings based on cassava starch and emulsion of lemongrass essential oil

This study aimed to evaluate the effect of applying oxidized cassava starch-based edible coatings with addition of lemongrass essential oil emulsion on ‘Palmer’ mangoes stored under refrigeration. A completely randomized design was used, arranged in a 5 × 3 factorial scheme, with five types of coatings and three evaluation times. The evaluated postharvest quality parameters consisted of weight loss, pulp and peel firmness, biochemical transformations related to pigments, and pulp and peel coloration of mango. The application of edible coatings with a 0.9 % EO concentration resulted in delayed fruit ripening, evidenced mainly by a 7.25 % reduction in weight loss, a 29.23 % increase in soluble solids content, and a 24.15 % decrease in total chlorophyll, when compared to uncoated fruits, which showed 19.8 %, 48.66 %, and 82.00 %, respectively, over the storage period. This effect was also evident in the angle Hue (°h) measurement, with uncoated fruits showing a decrease of 32.2 %. The antimicrobial effect and absence of anthracnose symptoms were observed in the fruits in which the coating with 0.9 % EO was applied. Therefore, biodegradable coating with the addition of 0.9 % emulsion EO, can be used as postharvest treatments for maintenance quality of ‘Palmer’ mangoes during refrigerated storage.

Insecticidal Activity of Allium sativum Essential Oil-Based Nanoemulsion against Spodoptera littoralis.

Spodoptera littoralis, commonly known as the Egyptian or African cotton leafworm, is a significant agricultural threat. It is widely distributed in Africa, Mediterranean Europe, and Middle Eastern countries. This polyphagous pest infests numerous crop plants across 44 families, including cotton, soybeans, alfalfa, sweet potato, pepper, eggplant, tomato, maize, lettuce, strawberry, wheat, and hibiscus. The damage caused by S. littoralis on different plant organs, such as young leaves, shoots, stalks, bolls, buds, and fruits, often determines substantial product losses. Current control strategies predominantly rely on synthetic insecticides, which, despite their efficacy, have notable drawbacks, including insecticide resistance, environmental contamination, consumer concerns, and adverse effects on non-target organisms and beneficial insects. In response to these challenges, in this study, we developed and evaluated a garlic EO-based nanoemulsion with a high EO concentration (15%) and low surfactant content to mitigate the possible negative impact on plants and to enhance efficacy against S. littoralis larvae. Laboratory bioassays demonstrated promising larvicidal activity and reduced larval feeding, although some phytotoxicity symptoms were observed. This study underscores the potential of botanical insecticides as sustainable alternatives to synthetic chemicals, emphasizing the importance of balancing efficacy with environmental and ecological considerations in pest management strategies.

Biological activity of essential oils of Calocedrus decurrens and Cupressus arizonica on Lymantria dispar larvae and Phytophthora root pathogens

Composition of Calocedrus decurrens and Cupressus arizonica essential oils (CDEO and CAEO, respectively), their antifeedant activity on spongy moth (Lymantria dispar) larvae, as well as their antimicrobial activity on three Phytophthora species were investigated. In leaves of these two conifers from the Cupressaceae family, monoterpenes strongly dominated (90.5 and 85.0%, respectively), but their terpene profiles were different. The dominant compound of CDEO was δ-3-carene (49.5%), followed by myrcene (9.4%), terpinolene (8.6%) and α-pinene (7.0%). In CAEO, the most dominant compounds were limonene (23.3%) and α-pinene (20.5%), followed by umbellulone (12.0%) and terpinen-4-ol (9.5%). CDEO showed a strong antifeedant activity, while leaf discs treated with CAEO had phagostimulatory effect on spongy moth larvae. CAEO had no significant effect on relative consumption and larval growth rate, while CDEO reduced consumption and stimulated growth at the lowest EO concentration (0.05%). Both EOs significantly affected the growth of colonies of the Phytophthora species tested. At concentrations of 0.5% and 1%, a 100% inhibition was observed in almost all experimental groups, with the exception of P. plurivora on 0.5% CDEO. At a concentration of 0.1% inhibition rate varied from 15% in P. ×cambivora treated with CDEO to 90% in P. quercina treated with CAEO. These findings indicate that these two EOs could be used to control tree pests.

Anti-oral streptococci and anti-biofilm properties of Etlingera pavieana essential oil and its bioactive compounds proposed for an alternative herbal mouthwash

Oral streptococci are the major group of bacteria in the oral cavity. Some of their species cause oral diseases that may lead to tooth loss and quality-of-life reduction, such as dental caries. One of prevention techniques to promote oral health is rinsing mouthwash after toothbrushing. This study aimed to determine the potential uses of local food, also remedy, plant in Thailand called Reaw-Horm or Etlingera pavieana for alternative herbal mouthwash. The essential oil from E. pavieana rhizome (Eo) is used for anti-streptococci including Streptococcus mutans and Streptococcus sobrinus and anti-biofilm activities. The main components of Eo are methyl chavicol (MC) and trans-anethole (TA). The disk diffusion method showed the inhibition zone of Eo in a dose-dependent manner. The minimum inhibitory concentration (MIC) of Eo and TA was >1.6 % v/v, and 0.4 % v/v of MC. Regarding anti-biofilm activities, MC showed nearly equal anti-biofilm formation of S. mutans and S. sobrinus, whereas Eo and TA acted toward S. sobrinus more than S. mutans biofilm. Sub-MIC killing effects on cells under biofilm were observed in Eo and MC. Therefore, MC was recommended as an active compound for anti-streptococci activities. Biocompatibility of Eo and MC were shown to be safe for epidermal cell lines. Herbal mouthwashes containing Eo were developed and had antioxidant and antimicrobial actions with established for 3 months. This study provides in vitro support on the use of herbal mouthwash with antioxidant and antimicrobial activities for dental caries prevention and well-being of individuals.

Optimization of Ziziphora clinopodioides L. essential oil nanoencapsulation in chitosan nanocomplex by response surface methodology

Nano-encapsulation of essential oils, a specific area of interest, can help overcome challenges associated with their commercial use. This study aimed to evaluate the effect of different concentrations of chitosan, Ziziphora clinopodioides L. essential oil (ZcEO), and Sodium-Tri Polyphosphate (TPP), both individually and in interaction, on several properties of EO-loaded chitosan nanoparticles. These properties include particle size (PS), zeta potential (ZP), and encapsulation efficiency (EE) using a two-stage emulsion-ionic gelation approach. The optimization of the parameters was done by response surface methodology using Box-Behnken design. The chemical composition of ZcEO was analyzed as well. The primary compounds in ZcEO were found to be pulegone (29.24 %), 1,3-dimethyl-2-(2-methylpropylidene) imidazolidine (9.05 %), piperitenone (6.65 %), thymol (5.38 %), and carvacrol (5.27 %). The PS ranged from 117.33 to 4934.1 nm, the ZP varied from −1.1 to −30.83 mV, and the EE spanned from 31.74 to 87.04 %. The results showed that an increase in the initial EO content led to a decrease in PS and ZP, but an increase in EE. Moreover, increasing the TPP concentration resulted in an enhancement in PS, ZP, and EE, whereas increasing the Chs concentration led to a slight increase in PS, ZP, and EE. Furthermore, the results of this study proved the interaction effect of different parameters on the responses investigated. Under optimized conditions, the optimal concentrations of chitosan, ZcEO and TPP were attained at 6.768, 6.078, and 7.595 mg/mL respectively. This resulted in a PS of 117.331 nm, a ZP of −20.949 mV, and an EE of 75.385 %. In conclusion, the results suggest that adjusting the concentrations of Chs, EO, and TPP is an effective approach to controlling the properties of NPs and optimizing their performance.

In-vitro Antimicrobial Study of Non/irradiated Ylang-ylang Essential Oil Against Multi Drug Resistant Pathogens with Reference to Microscopic Morphological Alterations

Essential oils have proven to possess great potential in the field of biomedicine due to their ability to effectively eradicate a diverse range of pathogenic microbes. In this study, the antimicrobial activity of ylang-ylang essential oil (YY-EO) was screened against twelve multidrug-resistant pathogens. The YY-EO was effective up to 536 μg/ml, with the highest inhibition zone in case of S. aureus MMCC21 and Escherichia coli MMCC24. The least effect on both Bacillus cereus MMCC11 and Klebsiella pneumonia MMCC16. The major components of the essential oil were identified using GC–MS analysis. Different gamma irradiation doses against the YY-EO were evaluated as a tool of natural decontamination. Moreover, the antimicrobial assay after irradiation proved no significant changes regarding the antimicrobial activity before and after irradiation of EO at the applied dose. The minimum inhibitory concentration (MIC) for the EO against the tested pathogens was detected. The possible morphological changes in some of the bacterial and yeast cells at the recognized MIC and 2MIC were detected using the scanning electron microscope (SEM). Results revealed a notable change in terms of both the microbial cell population and the morphology of the tested bacterial and yeast cells. The cytotoxicity of ylang-ylang EO was evaluated against normal skin tissue culture and showed a potential cytotoxic effect at concentrated doses. These results refer to the importance of YY-EO as a natural antimicrobial agent and the possible application of YY-EO as a surface decontaminant, but they also draw attention to the importance of the EO concentration used in different applications to avoid possible toxic effects.

Principles of Parametric Release: Emphasis on Data Collection and Interpretation.

Parametric release, which relies on use of process data for product release, provides many benefits. However, adoption by the sterilization industry has been slow, with release typically involving biological indicator (BI) growth responses/ dosimetry readings. The current article highlights how the data provided by the process (described through examples for ethylene oxide [EO], vaporized hydrogen peroxide [VHP], and radiation) may be better used to inform parametric release implementation. The examples involving EO and VHP demonstrated the ability of the sterilization equipment to deliver validated parameters repeatedly after the load presented was validated. For instances in which load variability has not been addressed in performance qualification, BI testing or even measurement of EO concentration cannot reliably or fully inform the impact of such variance on the validated process. "Direct" monitoring of EO concentration is a current requirement in ISO 11135:2014. Nonetheless, the findings presented here show that EO and VHP concentrations can be determined by the calculated method, rendering the use of a concentration measurement probe somewhat superfluous. In alignment with European Union good manufacturing practice Annex 17, a key requirement of parametric release is to have sufficient data to demonstrate the repeatability of the validated process. Similar to gas technologies, radiation processing strives to implement parametric release but is limited by the currently available means of measuring all critical parameters, such as photon delivery.

The Impact of Origanum vulgare Supplementation on Human Asthenozoospermic Sperm Parameter Quality.

Male infertility is a complex multifactorial disease and a real health problem; 50% of infertile men have identifiable causes detectable by fundamental sperm analysis. Numerous research studies have shown the possibility of treating abnormal semen samples with some drugs before artificial insemination, yet evidence of the drug's effectiveness remains minimal. In our previous work, we tested the effectiveness of some essential oils, such as eucalyptus (Eucalyptus globulus Labill.), oregano (Origanum vulgare L.), and sage (Salvia officinalis L.) on sperm parameters. The essential oil of oregano showed the best ameliorative effect. In present, we examined the effect of the essential oil of O. vulgare on the physiological parameters and the specific activity of certain antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), lipid peroxidation rate (MDA), and GAPDH and antioxidant and metabolic biomarkers, characterizing the quality of human sperm. The results showed that in vitro supplementation of oregano significantly improves the mobility and antioxidant activities, without harmful effects on the integrity of the sperm's DNA, and that the selected concentration of oregano EO is nontoxic and may be considered a therapeutic alternative to heal sperm motility problems in asthenozoospermic patients.

Evaluation of in-vitro antifungal activity against Fusarium incarnatum of binary and ternary combinations of lemongrass, garlic and mustard oil-encapsulated lipid nanoemulsions

Summary Encapsulated lipid nanoemulsions (EO-LNs) from garlic oil, lemongrass oil and mustard oil were prepared by a combined method of homogenization and sonication with the aim to generate highly effective formulations against Fusarium incarnatum (laboratory bioassays). Their combined binary and ternary formulations (preparations by mixing an equal volume ratio of each EO-LNs) were also tested. The synergistic/additive/antagonistic antifungal effect of the EOs (under nanoform) in their combined formulations was determined using the SynergyFinder software with the Bliss independence model. Results revealed the synergistic effect of the combined binary and ternary formulations of garlic oil-encapsulated LNs (NaG), lemongrass oil-encapsulated LNs (NaL) and mustard oil-encapsulated LNs (NaM). Furthermore, the ternary combination, at the same concentration of each constituent EO, had higher antifungal activity than the binary combinations. Nonetheless, at 600 times dilution the NaLG (binary combination) inhibited 96% the mycelial growth of F. incarnatum, which was significantly higher than the efficacy of NaMLG (ternary combination) in the same dilution. This could be possibly attributed to the 1.5-time higher concentration of each constituent EO in the binary combination compared to that in the ternary formulation. In addition, NaLG, even at the high EO concentration of 0.4 g/L, did not show any phytotoxicity symptoms on lettuce plants.

Impact of essential oil vapors inhalation on blood pressure in patients with hypertension

To perform the comparative study of antihypertensive effects of inhalation with EO vapors of various composition. The investigation included 849 women aged 55-89 years with hypertension. Two examination series were done: 10- and 20-minute duration procedures. Trial subjects were divided into control (psychorelaxation procedure) and experimental (psychorelaxation procedure combined with the EO inhalation of common basil, Italian immortelle, clove tree, common hyssop, cardamom, coriander, Caucasian nepeta, nepeta cataria, spicate lavender, bay laurel, the sort «Oxamitov» of brook-mint, the sorts «Prilutskaya», «Udaichanka», «Ukrainian» of pepper mint, the Siberian fir, Tauric wormwood, the sort «Crimean red» of rose, rosmarinus officinalis, Scotch pine, fennel, mountain savory, garden savory and clary sage; EO concentration in air - 1 mg/m3) groups. Systolic and diastolic blood pressure, heart rate were measured, as well as the coefficient of blood circulation efficiency and Robinson index were calculated before and after the examination in trial subjects. It has been established that the EO of clary sage, bay laurel, Caucasian nepeta and the sort «Oxamitov» of brook-mint have antihypertensive action at both 10-minute and 20-minute exposure. The antihypertensive action of EO of common basil, clove tree, coriander, nepeta cataria, the sort «Crimean red» of rose, rosmarinus officinalis, garden savory was found after 10-minute exposure. There was no antihypertensive action in EO application of Italian immortelle, common hyssop, spicate lavender, the sorts «Prilutskaya», «Ukrainian», «Udaichanka» of pepper mint, Siberian fir, tauric wormwood, Scotch pine and fennel. The EO vapors' inhalation of clary sage, bay laurel, Caucasian nepeta, the sort «Oxamitov» of brook-mint, common basil, clove tree, coriander, nepeta cataria, the sort «Crimean red» of rose, rosmarinus officinalis and garden savory can be a promising method to reduce blood pressure in patients with hypertension.

Potential antifungal activity of essential oil from Cymbopogon citratus (DC) Stapf and its performances as biostabilization of tiger nut milk (Cyperus exculentus)

Tiger nut milk is not heated during processing and is usually contaminated with spoilage microorganisms due to its high starch content. The present study aims to preserve tiger nut milk using essential oil from Cymbopogon citratus as an antimicrobial agent. The antifungal activity was evaluated by agar diffusion and micro-dilution methods. Storage tests were performed at 4°C by incorporating tiger nut milk with different concentrations of EO (i.e. 0.05; 0.10; 0.15; 0.20; 0.25; 0.30; 0.35; 0.40; 0.45 and 0.50 (% v/v)), after which the physicochemical and hygienic characteristics were assessed. The EO showed significant (p ˂ 0.05) inhibitory activity against A. niger (19.89 mm), C. albicans (26.30 mm), C. kefir (26.45 mm), C. tropicalis (27.31 mm), R. nigricans (27.45 mm) and S. cerevisiae KVL013 (25.52 mm) with MICs 15.62 (A. niger), 0.98 (C. albicans), 1.63 (C. kefir), 1.95 (C. tropicalis), 7.81 (R. nigricans) and 0.98 (S. cerevisiae KVL013). The results of the shelf-life monitoring showed that the milk samples were free of total and thermotolerant coliforms, Bacillus spores and sulphite-reducing anaerobes spores. At a concentration of 0.40 to 0.50% of EO and after 21 days, flora microbial load decreased in unpasteurized milk from 103 to 102 (CFU/mL) and yeasts/moulds decreased from 102 to 101 (CFU/mL), whereas in pasteurized milk, flora decreased from 103 to 10 (CFU/mL), and yeasts/moulds decreased from 102 to less than 101 (CFU/mL). This shows that the tiger nut milk remained stable and its hygienic quality complied with the standards set for spoilage flora and spores for 21 days at 4°C under refrigeration. The results obtained indicated that EO of C. citratus has strong antimicrobial activity on spoilage flora and the stabilisation concentration can be modulated for sensory acceptability.

Atmósfera modificada con microperforado incorporada con vapores de aceite esencial de orégano para preservar frutos de zarzamora en poscosecha

Blackberry fruits have a shelf life of 3 d at ambient temperature, due to fungal development. Essential oils (Eo) can increase shelf life because of their antifungal potential. The objective was to evaluate the use of modified atmosphere packaging incorporated with vapors of an Eo to prolong shelf life of blackberry fruits. The methodology included the use of oregano Eo to inhibit fungi development. Eo was analyzed with gas chromatography-mass spectrometry. The minimum inhibitory concentration of Eo to inhibit fungi in blackberry fruits was determined in vitro and in vivo. The storage of blackberry fruits under modified atmosphere with vapors of oregano Eo was evaluated at ambient temperature. The compounds linalool, o-cymene, and thymol were identified as the main constituents of Eo. Based on fruits with fungal development, isolates were made in culture media and the presence of Aspergillus carbonarius, Alternaria alternata, and Penicillum digitatum was identified. A minimum inhibitory concentration of Eo in the head space of fruits was found with value of 0.8 μL·mL-1. The handling of blackberry fruits in modified atmosphere with micro-perforation and exposition to volatilized Eo (MAP-Eo) reduced the rate of weight loss, the loss of consistency, and that of alteration of color attributes, which allowed maintaining a better appearance during 6-7 d at 23 °C. MAP-Eo kept the content of phenolic compounds and anthocyanins, as well as the antioxidant capacity, without significant changes. In conclusion, MAP-Eo is a useful alternative to extend shelf life of blackberry fruits.

The responses of marine anammox bacteria-based microbiome to multi-antibiotic stress in mariculture wastewater treatment

Saline mariculture wastewater containing multi-antibiotics poses a challenge to anaerobic ammonia oxidation (anammox) process. Herein, the halophilic marine anammox bacteria (MAB)-based microbiome was used for treating mariculture wastewater (35‰ salinity) under multi-antibiotics (enrofloxacin + oxytetracycline + sulfamethoxazole, EOS) stress. And the main focus of this study lies in the response of MAB-based microbiome against multi-antibiotics stress. It is found that MAB-based microbiome shows stable community structure and contributes high nitrogen removal efficiency (>90%) even under high stress of EOS (up to 4 mg·L−1). The relative abundance of main functional genus Candidatus Scalindua, responsible for anammox, had little change while controlling the influent EOS concentration within 4 mg·L−1, whereas, significantly decreased to 2.23% at EOS concentration of as high as 24 mg·L−1. As an alternative, antibiotic resistance bacteria (ARB) species Rheinheimera dominated the microbial community of MAB-based biological reactor under extremely high EOS stress (e.g. 24 mg·L−1 in influent). The response mechanism of MAB-based microbiome consists of extracellular and intracellular defenses with dependence of EOS concentration. For example, while EOS within 4 mg·L−1 in this study, most of the antibiotics were retained by extracellular polymeric substances (EPS) via adsorption; If increasing the EOS concentration to 8 and even 24 mg·L−1, part of antibiotics could intrude into the cells and cause the intracellular accumulation of antibiotic resistance genes (ARGs) (total abundance up to 2.44 × 10−1 copies/16S rRNA) for EOS response. These new understandings will facilitate the practical implementation of MAB-based bioprocess for saline nitrogen- and antibiotics-laden wastewater treatment.

In Vitro and In Silico Screening of Anti-Vibrio spp., Antibiofilm, Antioxidant and Anti-Quorum Sensing Activities of Cuminum cyminum L. Volatile Oil.

Cuminum cyminum L. essential oil (cumin EO) was studied for its chemical composition, antioxidant and vibriocidal activities. Inhibition of biofilm formation and secretion of some virulence properties controlled by the quorum sensing system in Chromobacterium violaceum and Pseudomonas aeruginosa strains were also reported. The obtained results showed that cuminaldehyde (44.2%) was the dominant compound followed by β-pinene (15.1%), γ-terpinene (14.4%), and p-cymene (14.2%). Using the disc diffusion assay, cumin EO (10 mg/disc) was particularly active against all fifteen Vibrio species, and the highest diameter of growth inhibition zone was recorded against Vibrio fluvialis (41.33 ± 1.15 mm), Vibrio parahaemolyticus (39.67 ± 0.58 mm), and Vibrio natrigens (36.67 ± 0.58 mm). At low concentration (MICs value from 0.023–0.046 mg/mL), cumin EO inhibited the growth of all Vibrio strains, and concentrations as low as 1.5 mg/mL were necessary to kill them (MBCs values from 1.5–12 mg/mL). Using four antioxidant assays, cumin EO exhibited a good result as compared to standard molecules (DPPH = 8 ± 0.54 mg/mL; reducing power = 3.5 ± 0.38 mg/mL; β-carotene = 3.8 ± 0.34 mg/mL; chelating power = 8.4 ± 0.14 mg/mL). More interestingly, at 2x MIC value, cumin EO inhibited the formation of biofilm by Vibrio alginolyticus (9.96 ± 1%), V. parahaemolyticus (15.45 ± 0.7%), Vibrio cholerae (14.9 ± 0.4%), and Vibrio vulnificus (18.14 ± 0.3%). In addition, cumin EO and cuminaldehyde inhibited the production of violacein on Lauria Bertani medium (19 mm and 35 mm, respectively). Meanwhile, 50% of violacein inhibition concentration (VIC50%) was about 2.746 mg/mL for cumin EO and 1.676 mg/mL for cuminaldehyde. Moreover, elastase and protease production and flagellar motility in P. aeruginosa were inhibited at low concentrations of cumin EO and cuminaldehyde. The adopted in-silico approach revealed good ADMET properties as well as a high binding score of the main compounds with target proteins (1JIJ, 2UV0, 1HD2, and 3QP1). Overall, the obtained results highlighted the effectiveness of cumin EO to prevent spoilage with Vibrio species and to interfere with the quorum sensing system in Gram-negative bacteria by inhibiting the flagellar motility, formation of biofilm, and the secretion of some virulence enzymes.

Cinnamomum verum uçucu yağının Pseudomonas aeruginosa ve Acinetobacter baumannii üzerindeki antibakteriyel ve antibiyofilm etkisi ile anti-quarum sensing aktivitesi

Objective: The emergence of multi-drug-resistant pathogens on antimicrobials in current use has made it necessary to search for alternative treatment strategies. Plant essential oils are considered as alternative antimicrobials in the treatment of diseases because they are non-toxic, cost-effective and accessible. This study aimed to evaluate the antibacterial and antibiofilm effect and anti-quarum sensing (QS) properties of Cinnamomun verum leaf essential oil on Pseudomonas aeruginosa and Acinetobacter baumannii. Materials and Methods: In the study, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of EO on P. aeruginosa and A. baumannii were determined. The microdilution method was used to determine the minimum inhibitory concentrations (MICs). The chemical content of C. verum EO was determined using Gas Chromatography-Mass Spectrometry (GC-MS). Results: C. verum EO showed MIC and MBC at 0.5 and 1.0 mg/mL versus strains tested. It was determined that C. verum EO showed high anti-QS activity at a concentration of 2 mg/mL. According to GC-MS results, cinnamaldehyde was found to be the most abundant compound in C. verum EO. Conclusion: C. verum EO has potential to be used against infections caused by bacterial biofilms. Studies on the anti-QS activity of C. verum EOs are limited, and the anti-QS activity on pathogenic microorganisms should be investigated in this area.

Citrus paradisi and Citrus reticulata essential oils interfere with Pseudomonas aeruginosa quorum sensing in vivo on Caenorhabditis elegans

Background: Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen, considered a leading cause of acute and chronic infections in immunocompromised patients. P. aeruginosa uses quorum sensing to control virulence and biofilm formation. To combat this human-resistant pathogen increasing attention has been paid to anti-QS compounds from natural products as potential therapeutic agents. Purpose: To assess the efficacy of C. paradisi (Grapefruit) and C. reticulata (Mandarin) commercial EOs (obtained by cold-pressing and cold-pressing followed by steam distillation, named EOP and EOPD, respectively) and their majority component, limonene, in inhibiting the effect of QS-controlled virulence factors of P. aeruginosa PAO1 and PA14 in a C. elegans infection model. Results: C. paradisi and C. reticulata EOs at 0.125% (v/v) significantly inhibited the in vitro biofilm formation of PAO1 and PA14 strains between 40 and 50%. This EOs concentration, safe for C. elegans according to the survival and brood size assays, rescued the nematodes from P. aeruginosa infections, reducing their death rate by 20–30% in the paralysis assay, and increasing worm lifespan with median survivals of 6 (Grapefruit) and 5 (Mandarin) in the slow killing assay (3 for non-treated worms). Limonene protected nematodes from death in these assays although less effectively than both EOs species. Grapefruit EOs rescued the nematodes in 45–50% from phenazine-death, while mandarin EOs and limonene rescued them in 30%. In the food choice assay, worms preferred the PA14 grown with 0.125% of mandarin and grapefruit EOs or limonene after 3-4 hours (CI=0.11 to 0.18). Conclusion: Our results suggest that C. paradisi and C. reticulata EOPDs, with lower commercial value but similar in vivo effects than EOPs, are sources of anti-QS agents for controlling P. aeruginosa infections, therefore should be considered as potential candidates for the development of novel therapeutics against persistent microorganisms.

Factors influencing embryo quantity and quality in donor cows from Latvian Blue, Latvian Brown, and Danish Red breeds at risk in Latvia

The aim of this study was to find out what general factors influenced embryo quantity and quality in the framework of multiple ovulation and embryo transfer done in Latvia 2018–2020. The gene-pool cows from the cattle breeds Latvian Blue, Latvian Brown, and Danish Red (n = 30) were selected. Such factors as the donor`s blood biochemical and hematological parameters value, ovarian steroid hormones level, milk somatic cell count (SCC), parity, and environmental temperature were analyzed using a negative-binomial regression method. The variables significant at a liberal alpha level of 0.20 in univariable regression models were included in two multivariable models. The first model showed that the number of embryos (nE) was associated (P < 0.01) with a higher progesterone (P4) level and blood absolute count of eosinophils (Eo) on the first day of multiple ovulation (MO) treatment, with a lower SCC and average daily air temperature in the month preceding embryo collection, and lower parity. It can be predicted according to the nE model, if P4 level or Eo absolute count is increasing by the interquartile range (IQR), and provided that the other associated parameters remain constant, the nE will be higher by 2.9 and 4.4 embryos, respectively. If SCC or temperature is increasing by the IQR, the nE will be lower by 4.7 and 15.2 embryos, respectively. Additionally, the nE model predicted 13.3 more embryos in primiparous than in multiparous donors. The second model showed that the number of transferable embryos (nTE) was associated (P < 0.05) with a higher Eo and serum sodium (Na+) concentration on the first day of MO treatment, and with a lower SCC and average daily air temperature in the month preceding embryo collection. It can be predicted according to the nTE model, if Na+ level or Eo absolute count is increasing by the IQR, the nTE will be higher by 3.7 and 2.4 embryos, respectively. If SCC or temperature is increasing by the IQR, the nTE will be lower by 3.3 and 6.4 embryos, respectively.

Evaluating the in vitro Cytotoxicity of Thymus vulgaris Essential Oil on MCF-7 and HeLa Cancer Cell Lines

Thyme essential oil (TEO) was extracted from dried leaves of Thymus vulgaris. The air-dried aerial parts of the plant produced 1.0% yield of TEO. The detection of this essential oil’s compounds was performed by GC-MASS. The cytotoxic activity of TEO was evaluated against two human cancer cell lines, namely HeLa (human epithelial cervical cancer) and MCF-7 (human breast carcinoma). Cells grown in 96 multi-well plates were treated with six concentrations of EO (6.25, 12.5, 25, 50, 100, 200 ppm) and incubated at 37 °C for 72 hrs. Cancer cell lines elicited various degrees of sensitivity to the cytotoxic effect of essential oil. The TEO exhibited significant differences (p≤ 0.01) between the effects of all concentrations against these two human cell lines. The results showed the highest toxicity of TEO on HeLa cell line (78.67%) and MCF-7 cell line (83.60%) at 200 ppm concentration. Also the values of half-maximal inhibitory concentration (IC50) of TEO against HeLa and MCF-7 cell lines were 34.63 and 27.66 ppm, respectively. Cells treated with the IC50 of TEO showed a significant difference (p ≤ 0.01) in p53 fold expression between HeLa cell line (4.33±0.41 folds) and MCF-7 cell line (5.10±0.32 folds). In general, a dose-dependent decrease the survival of the two cell lines was observed. In addition, MCF-7 cell line revealed higher sensitivity against TEO than HeLa cell line.

Natural preservative efficacy of cured betel leaf essential oil for sapota juice: Effect on physicochemical, microbial, and sensory properties

The potential of cured betel leaf essential oil (CLEO) as a natural food preservative was studied in sapota juice and ensuring its acceptable concentration. Physico-chemical properties of CLEO enriched sapota juice showed that the pH, total soluble solid (TSS), titratable acidity (TA), ascorbic acid (AA) significantly increased while TA, AA significantly reduced under the refrigerated condition of 4℃ for 30 days of storage period. Microbial properties of sapota juices showed that CLEO oil-enriched juice exhibited a strong antimicrobial activity compared to control sapota juice samples. The study revealed that EO enriched juice with a higher percentage of chemical compounds like eugenol, estragole, and linalool are responsible for controlling microbial growth. The chemical groups were identified by Fourier-transform infrared spectroscopy. The CLEO's best organoleptically acceptable concentration was found to be 0.3 µl/ml in terms of physicochemical properties, microbial and sensory properties without alteration of quality parameters during the storage period. Practical applications The current research study explores the effect of cured betel leaf essential on sapota fruit juice that is stored at 4℃ for 30 days of storage period and to study the changes in physico-chemical properties as well as antimicrobial activity. The EO is considered as a natural food preservative having antimicrobial activity instead of using synthetic ones. The concentration of betel leaf EO, which was organoleptically acceptable, can enhance the shelf-life period of treated sapota fruit juice. The CLEO-treated juice can be applicable at an industrial level, having several major chemical compounds, such as eugenol, estragole, linalool, etc.

Vepris macrophylla Essential Oil Produces Notable Antiproliferative Activity and Morphological Alterations in Human Breast Adenocarcinoma Cells

Medicinal plants contain numerous bioactive molecules that synergistically provide therapeutic benefits. We have devoted our attention to various EOs without toxicity to normal cells, studying their activities against human cancer cells. In particular, we have studied the cytotoxicity of Vepris macrophylla (Baker) I. Verd. EO. V. macrophylla is an evergreen tree of Madagascar where is much appreciated as a source of traditional remedies. Its major volatile components are citral, i.e., a mixture of neral and geranial, citronellol and myrcene. The antiproliferative activities of V. macrophylla EO were studied against human breast adenocarcinoma cell line SKBR3. Cellular metabolism was analyzed by MTT assay at different concentrations of EO and at different times of incubation (24, 48 and 72 h). Moreover, morphological and ultrastructural analyses were performed to study its antiproliferative effects against human adenocarcinoma cells, demonstrating the ability of V. macrophylla EO, stored inside numerous intracellular vesicles, to damage both plasma membranes and disorganize the cytoskeleton protein as actin filaments.