Commercial Essential Oils Research Articles

Antimicrobial Activity of Commercial Essential Oils Available in the Market of Kathmandu

Given the increasing global apprehension surrounding antibiotic resistance, there has been growing interest in exploring natural compounds, specifically essential oils, as potential substitutes for combating microbial pathogens. This research work aimed to evaluate the antimicrobial activity exhibited by commercial essential oils and by diluting them with the carrier oils at equal concentration. The screening of antimicrobial activity was conducted using the agar well diffusion method with eight essential oils. Using the broth dilution method, the antibacterial activity of eight commonly used essential oils: lavender, tea tree, eucalyptus, peppermint, thyme, citrus, rosemary, and cinnamon were assessed. Both Gram-positive and Gram-negative species were selected for antimicrobial activity. The minimum inhibitory concentration (MIC) was determined by the broth dilution method. Following MIC determination, a sub-culture was performed on nutrient agar plates to ascertain the minimum bactericidal concentration (MBC). All the antibiotics used in the study demonstrated sensitivity when subjected to the antibiotic susceptibility test. Thyme, cinnamon and peppermint strongly inhibited the growth of S. epidermidis 46 mm, 30mm, and 34 mm respectively. Findings revealed distinct variations in the MIC values among the different essential oils and bacteria tested. Thyme and tea tree oils exhibited the broadest antibacterial spectrum, inhibiting both Gram-positive and Gram-negative bacteria at relatively low concentrations. Thyme (15.625 μl/ml) and tea tree (31.25 μl/ml) oil demonstrated promising activity against Gram-positive pathogen, while tea tree oil (15.625 μl/ml) displayed better efficacy against Gram-negative bacteria. A significant outcome was observed when the essential oils were diluted with carrier oils, indicating promising results in terms of antibacterial activity. These findings highlight the potential of essential oils, particularly thyme and tea tree oils, as effective natural antimicrobial agents.

Lavender essential oil market integrity: A comprehensive study of commercial Lavandula angustifolia essential oils adulteration and assessment of industrial standards

Adulteration of essential oils (EOs) is a common and unethical practice that affects both consumers and honest suppliers and harms market integrity. Despite the awareness of this problem, scarce scientific studies are described in the scientific literature. Therefore, 55 samples of lavender EOs were purchased and extensively analyzed to the trace levels, including chromatographic profile, quantitative analysis, and chiral profile. Of the 51 samples labeled as Lavandula angustifolia, 51 % were genuine, 6 % were cheaper lavandin EO, 14 % were fortified with synthetic additives and over 29 % of the samples were adulterated with both lavandin EO and synthetics. Usually, adulterated EOs were cheaper than genuine products, still some expensive products were also falsified. The most common synthetic adulterants were synthetic linalool and linalyl acetate, 3,5,5-trimethylhexyl acetate, α-terpinyl acetate, and dipropylene glycol. Only four of the studied samples were diluted with a medium not fully visible in the recorded GC profile. Industry standards were assessed to eliminate adulterated EOs and ISO 3515 was found to be impractical and too strict, but Ph. Eur. demonstrated its efficiency in eliminating adulterated samples without rejecting many genuine ones.PCA enabled the differentiation of lavender EOs containing synthetics from those of purely natural origin, and in the latter group, to distinguish L. angustifolia from lavandin. Some samples had an unusual composition suggesting that they were artificial blends of synthetics and some terpene fractions of non-lavender origin.This is the first such extensive study of adulteration of lavender EOs, regarding both the number of commercial samples as well as implications on their biological activity. The adulteration via dilution influenced the antimicrobial activity of the essential oils. In conclusion, adulteration is a significant problem in the market, and a large share of products on the market is somehow counterfeited, not only the cheapest products.

Tea tree essential oil and its impact on blue mold, volatile compounds, and postharvest quality of ‘Fuji’ apples: A study of laboratory-extracted and commercial essential oils

This study evaluated the effects of tea tree essential oil (TTO) on blue mold severity, volatile compound profiles, and postharvest quality of ‘Fuji’ apples during cold storage. Two experiments were conducted using laboratory-extracted TTO from Brazil and commercial TTO from Australia, applied by vaporization at various concentrations. Both types of TTO affected major volatile compounds, including terpinen-4-ol, γ-terpinene, and α-terpinene. The laboratory-extracted TTO had higher of 1,8-cineole, while commercial TTO had more p-cymene. TTO reduced blue mold severity up to 115 μL L−1 (laboratory) and 99 μL L−1 (commercial). Ethylene production decreased with laboratory-extracted TTO up to 64 μL L−1, while commercial TTO decreased ethylene production. Laboratory TTO increased the respiratory up to 41 μL L−1 before declining, whereas commercial TTO continuously decreased the respiratory. Higher concentrations of laboratory TTO decreased flesh firmness and lightness.TTO types altered the apples' volatile profiles, reducing ‘Fuji’ apple aromas.

Active Polysaccharide-Based Films Incorporated with Essential Oils for Extending the Shelf Life of Sliced Soft Bread.

Active, fully biobased film-forming dispersions (FFDs) with highly promising results for sliced soft bread preservation were successfully elaborated from carboxymethyl cellulose (CMC) and chitosan (CH) using a simple method based on pH adjustments. They consisted of the association of polysaccharides and oleic acid (OL) added with cinnamon (CEO) or ginger (GEO) essential oils. The chemical compositions of the commercial essential oils were first determined via GC/MS, with less than 3% of compounds unidentified. The films obtained from FFDs were characterized by SEM, FTIR and DSC, indicating specific microstructures and some interactions between essential oils and the polymer matrix. CEO-based films exhibited higher antioxidant properties and a lower minimal inhibitory concentration in terms of antifungal properties. From experiments on sliced soft bread, the ginger-based films could increase the shelf life up to 20 days longer than that of the control. Even more promising, cinnamon-based films led to complete fungal inhibition in bread slices that was maintained beyond 60 days. Enumeration of the yeasts and molds for the FFD-coated breads revealed complete inhibition even after 15 days of storage with the FFDs containing the highest concentration of CEO.

Commercial thyme essential oil as natural beverage preservative and molecular docking study on its mode of action against Saccharomyces cerevisiae

Commercial thyme essential oil as natural beverage preservative and molecular docking study on its mode of action against Saccharomyces cerevisiae

Acaricidal potential of essential oils on Rhipicephalus linnaei: Alternatives and prospects

The acaricidal potential of various essential oils (EOs) has been evaluated based on their benefits in tick control. This study aimed to investigate the tick-killing activity of Pogostemon cablin “patchouli,” Cymbopogon martinii “palmarosa,” and Cymbopogon flexuosus “lemongrass” EOs on Rhipicephalus linnaei. Engorged females were collected from domiciled and non-domiciled dogs from Jataí city, Goiás state, to obtain larvae and nymphs in a controlled environment. Two commercial EOs brands were used in this study in different EOs concentrations (2.5, 5, 10, and 20 mg/mL), and was tested by immersion of larvae and nymphs. In the in vitro evaluation of EOs toxicity against R. linnaei larvae, 100 % mortality was achieved with 10 mg/mL of P. cablin oil, whereas mortality rates greater than 98 % were observed with 20 mg/mL of C. martinii and C. flexuosus. In nymphs, high sensitivity was observed, with 100 % mortality achieved using 5 mg/mL of P. cablin and 20 mg/mL of C. martinii and C. flexuosus. The EO of P. cablin “patchouli” demonstrated in vitro toxicity at a lower concentration than the other oils in the two development stages of R. linnaei, and was considered the most efficient and with verified acaricidal activity. Oils of C. martinii “palmarosa” and C. flexuosus “lemongrass” achieved mortality greater than 95 % in larvae and nymphs only at the highest concentration. Therefore, the acaricidal effects of the tested EOs are promising, especially of patchouli oil, which promoted high mortality at a low concentration (LC90 of 2.21 mg/mL).

Fennel (Foeniculum vulgare Mill.) essential oil: The chemical profile, biological activity, and utilization of the commercial products

Laboratory-isolated essential oils are commonly used in experiments regarding their utilization as natural antioxidant and antimicrobial agents. This study analyzed commercially available essential oils (Serbian-FSR and Russian-FRU) of fennel (Foeniculum vulgare Mill.) and added to the pork patties to investigate their possible role as natural antioxidant and antimicrobial agents. Chemical analysis of the samples showed significant differences in profiles caused by geographical origin and other environmental factors. The main compound in both samples was trans-Anethole, but it had a much higher content in Serbian oils. On the contrary, Russian oil had a high portion of anisaldehyde and linalool. These diversities are the main reason for thermal behavior and biological activity differences. The thermal analysis has shown that FSR had a crystalline form in the solid state, while FRU had an amorphous form. During heating, in FSR, a single-step weight loss was detected, while in FRU, a two-step weight loss was observed, indicating that, in addition to evaporation, components in FRU interacted with each other, forming lesser volatile molecules. After adding pork patties, Russian oil showed higher potency and better protective behavior than Serbian oil. Moreover, mixtures of these oils were added to the patties samples, and results showed higher potency when compared to individual oil samples. This indicated that minor compounds from both oils interacted and synergistically acted to prolong the shelf life of the meat samples. Commercial essential oils could be successfully utilized to prolong shelf life and provide additional intake of natural compounds significant for the human diet.

Screening of botanical spatial mosquito repellents from 64 essential oils and their interactions with odorant‐binding protein‐3

AbstractPersonal protection from mosquito bites is essential for preventing mosquito‐borne diseases. Mosquito repellents are effective methods for preventing mosquito bites. Due to their ease of use and indirect skin contact, mosquito‐repellent stickers loaded with essential oils (EOs) have recently become favoured as novel spatial repellents. To discover active EOs with high spatial repellency, 64 commercial EOs were screened using a modified arm‐in‐cage assay. Four EOs, including nutmeg, melissa, eucalyptus and cinnamon, displayed longer complete protection times (CPTs) of about 60 min. Ten main constituents from the four active EOs were identified by gas chromatography–mass spectrometry (GC–MS), and their spatial repellent activities were further evaluated. 1,8‐Cineole, cinnamaldehyde and citral showed potent repellent activity, with average CPTs of 67.5, 63.8 and 60 min respectively. The interactions of 1,8‐cineole and citral with odorant‐binding protein‐3 (OBP‐3) were studied via molecular docking. Both compounds are docked well in the high hydrophobic pocket and interacted with AealOBP3 through Van der Waals interactions with Phe105, Phe112, Leu114, Met48 and Val50. These natural products provide promising lead fragments for the further development of botanical spatial repellents.

Comparative studies of essential oils from Matricaria recutita L.

The aim of the work is to determine the component composition of the essential oil of medicinal chamomile, grown on the educational and research site of medicinal plants of Zaporizhzhia State Medical and Pharmaceutical University (ZSMPHU), and commercial essential oil that was purchased via the Internet. Materials and methods. The object of the study was chamomile essential oil obtained by hydrodistillation and commercial oil. Qualitative and quantitative determination of the components of essential oils was established using the chromato-mass spectrometric method on a high-performance gas chromatograph “Agilent 7890B GC System” (Agilent, SantaClara, CA, USA) with a mass spectrometric detector “Agilent 5977 BGC/MSD” (Agilent, SantaClara, CA, USA). Results. Dominant compounds of essential oil of chamomile, grown on the educational and research site of medicinal plants ZSMPHU were 2H-pyran-3-ol, tetrahydro-2,2,6-trimethyl-6-(4-methyl-3-cyclohexen-1-yl) ) – 7.54 %, chamazulene – 5.32 %, alpha-bisabolol – 4.30 %, 1H-cycloprop[e]azulen-7-ol, decahydro-3,1,7-trimethyl-4-methylene – 3.25 %, myrtenyl acetate – 3.03 %, azulene, 1,2,3,3a,4,5,6,7-octahydro-1,4-dimethyl-7-(1-methylethenyl) – 2.16 %, bisabolol oxide B – 1.86 %. Commercial chamomile essential oil was dominated by 3-methoxy-3-methylbutanol (56.15 %), diethyl phthalate (17.46 %), linalyl acetate (6.99 %), linalool (4.41 %). Conclusions. Industrial cultivation of chamomile in southern Ukraine shows a high biologically active substances content and can be in demand in the pharmaceutical industry’s consumer market for raw materials.

Evaluation of Ten Alternative Treatments for the Management of Harlequin Bug (Murgantia histrionica) on Brassica Crops.

Harlequin bug (Murgantia histrionica) poses a significant threat to cruciferous vegetable crops, leading to economic losses and challenges in sustainable agriculture. This 2-year field study evaluated the efficacy of exclusion netting and selected biopesticides in controlling harlequin bug populations in a field-grown broccoli crop. Treatments included an untreated control, industry standards Azera and Entrust, and ProtekNet mesh netting. Additionally, three commercial essential oil treatments including Essentria IC-3, Nature-Cide, and Zero Tolerance were tested along with two bokashi fermented composting products BrewKashi and Oriental Herbal Nutrient (OHN). During both the first and second year of the study, none of the commercially produced essential oil products or bokashi products were effective in controlling harlequin bug or preventing leaf scars. Conversely, ProtekNet consistently provided the highest level of protection against harlequin bugs of all stages as well as leaf damage scars; it also provided the largest broccoli head width and highest yield. Entrust showed similar results compared to ProtekNet, both with the control of harlequin bug life stages and with leaf scars. These findings indicate that both ProtekNet and Entrust are effective organic alternatives for managing harlequin bug on broccoli, while the selected essential oil and bokashi products do not appear to be effective.

Chemical, antioxidant, and antifungal analysis of oregano and thyme essential oils from Ecuador: Effect of thyme against Lasiodiplodia theobromae and its application in banana rot

The objective of this study was to evaluate the antioxidant capacity by spectrophotometric methods, the in vitro and in vivo antifungal effect against Lasiodiplodia theobromae and the constitution of the essential oils (EO) of oregano and thyme in comparison with their commercial counterparts. The results showed by the EOs of extracted thyme (T-EO), commercial thyme (CT-EO), extracted oregano (O-EO) and commercial oregano (CO-EO), demonstrated antioxidant profiles with a radical neutralizing potential (DPPH•) of IC50: 1.11 ± 0.019; 1.08 ± 0.05; 40.56 ± 0.227 and 0.69 ± 0.004 mg/mL, respectively. They also revealed a ferric ion reducing capacity (FRAP) of 93.05 ± 0.52; 97.72 ± 0.42; 21.85 ± 0.57 and 117.24 ± 0.64 mg Eq Trolox/g. A reduction in β-carotene degradation of 65.71 ± 0.04; 51.97 ± 0.66; 43.58 ± 1.56 and 57.46 ± 1.56 %. A total phenol content (Folin-Ciocalteu) of 132.97 ± 0.77; 141.89 ± 2.56; 152.04 ± 0.10 and 25.66 ± 0.40 mg EGA/g. Chemical characterization performed by gas chromatography mass spectrometry (GC-MS) showed that the respective major components of the samples were thymol (T-EO: 45.78 %), thymol (CT-EO: 43.57 %), alloaromadendrene (O-EO: 25.17 %) and carvacrol (CO-EO: 62.06 %). Regarding antifungal activity, it was evident that at the in vitro level, both commercial EOs had a MIC of 250 ppm while the extracted thyme EO had a MIC of 500 ppm; In vivo studies demonstrated that the application of thyme EO had a behavior similar to the synthetic fungicide, slowing down rot in bananas under storage conditions. Finally, partial least squares discriminant analysis (PLS-DA) and heat maps suggest p-cymene, carvacrol, linalool, eucalyptol, 4-terpineol, (z)-β-terpineol, alkanhol, caryophyllene, β-myrcene, d-limonene, α-terpinene, α-terpineol, d-α-pinene, camphene, caryophyllene oxide, δ-cadinene, terpinolene and thymol as relevant biomarkers associated with the assessed bioactive properties demonstrating the potential of extracted essential oils for the development of a botanical biofungicide.

Harnessing Nature's Arsenal: Investigating the Antibacterial Efficacy of Commercial Essential Oils against Staphylococcus Strains Isolated from Poultry Meat.

Pathogens prevalent in the food supply chain provide a significant worldwide risk to both human health and the economy. Poultry meat, a staple in global diets, serves as a reservoir for bacterial contamination. Staphylococcus, a gram-positive bacterium belonging to family Staphylococcaceae has been identified as a potential causative agent of food borne illnesses. The presence of antibiotic-resistant Staphylococcus strains in poultry products raises concerns about the transmission of resistance genes through the food chain, necessitating thorough investigations into alternative antimicrobial agents for effective bacterial control. Essential oils (EOs) hold profound importance in terms of their known and potential application. This study focuses on the evaluation of commercial essential oils and their effectiveness against Staphylococcus strains isolated from poultry meat. Briefly, 150 raw chicken meat samples were collected, and Staphylococcus spp. was identified based on morphological and cultural characteristics. Antibiogram analysis and essential oils activity was determined by disc diffusion and agar well diffusion assay respectively. Results showed that 27 (18%) samples tested positive for Staphylococcus spp, out of which S. aureus was identified in 25 isolates (16.66%). The antibiogram profile reveals that three antibiotics namely, gentamicin, vancomycin and ciprofloxacin were the most effective antibiotics showing sensitivity against 74.07%, 70.37% and 62.96% of the isolates respectively. Moreover, amongst the tested essential oils cinnamon oil and clove oil exhibited the highest antimicrobial activities ZOI ranges from 19-41mm and 19-33 mm respectively. While focusing on the evaluation of antimicrobial activity of essential oils, the study endeavors to aid in development of sustainable strategies for mitigating bacterial contamination in the food industry.

The Effect of Commercial Essential Oil Mixture Applied to Neonatal Simmental Calves on Growth, Development and Health Parameters

In this study, the effectiveness of commercial essential oil mixture application in preventing calf losses due to diarrhea and on the growth, development and health parameters of calves was investigated. For this purpose, 24 newborn Simmental calves were used. Following birth, 20 ml of essential oil mixture was given orally via syringe to the calves in the treatment group after drinking milk in the morning for 5 days. The average birth weight of calves was 39.0 ± 0.72 kg. Birth weight of male and female calves were 42.3 ± 1.01 and 38.6 ± 0.96 kg respectively, the difference between groups were found significant. First month weight was 45.7 ± 1.67, 42.4 ± 1.65 kg in the control and treatment groups, respectively. There was no difference between the control and treatment groups in terms of body measurements taken at birth, but a significant difference was observed in chest circumference in favor of the control group in terms of measurements obtained at the 1st month. There was no difference between the treatment and control groups in terms of hematological parameters detected in the blood taken on the 10th day and in the 1-month period. No differences were observed between groups in terms of immunoglobulin levels (IgM and IgG). There was no effect of the commercial essential oil mixture on the fecal score of the calves included in the trial. It was revealed that the essential oil mixture does not make any difference in the growth, development and health of Simmental calves in a one-month period. In future studies on the subject, it is recommended that higher doses of the essential oil mixture be investigated.

Insecticidal Activity of Essential Oils and Their Synergistic Effect on Improving the Efficacy of β-Cypermethrin against Blattella germanica.

We screened the contact activity of 32 commercial essential oils (EOs) and their synergistic effect with β-cypermethrin against Blattella germanica. Results showed that the most effective EOs against B. germanica were from Illicium verum, Syzygium aromaticum, and Cinnamomum camphora, with LD50 values of less than 500 μg/insect. The most potent synergistic effects of β-cypermethrin on B. germanica were from Dysphania ambrosioides and Mentha canadensis. Both oils have a co-toxic factor of 133.33. The results of the major compound testing of the EOs showed that trans-anisaldehyde and thymol have the best insecticidal activity against B. germanica, with LD50 values of 141.30 and 138.61 μg/insect, respectively. The compounds with the best synergistic effect on β-cypermethrin were γ-terpinene and linalool at a concentration of 0.5%. The co-toxic factors for γ-terpinene and linalool were 150 and 133.33, respectively, which were similar to the synergistic effect observed with 2% piperonyl butoxide.

Study of antimicrobial properties of liquid plaster containing of oregano essential oil (Origanum vulgare L.)

Treatment of wounds resulting from combat injuries is complicated by the addition of a secondary infection caused by multi-resistant bacteria. The liquid patch appears to be a promising formulation for wound therapy. The antimicrobial effect of essential oils is manifested due to the content of numerous components that interfere with the proliferation and formation of bacterial resistance. The aim of the work was to substantiate the choice of Origanum vulgare L. essential oil as the main active ingredient of a liquid patch with antimicrobial action, confirm the composition of the essential oil and study the antimicrobial properties of the model drug. The object of the study were model samples of a liquid patch with an experimentally developed film-forming system. Various concentrations of commercial essential oil of O. vulgare L., the composition of which was confirmed by GB/MS analysis, were used as the active pharmaceutical ingredient. Antimicrobial activity was studied by direct contact method using microbial culture tests. The use of liquid patch in the treatment of skin lesions of various etiologies, including combat wounds, is justified. The variability of the composition of the essential oil of O. vulgare L. depending on the subspecies, chemotype and growth conditions of the plant is discussed. The component composition of a commercial sample of O. vulgare L. essential oil, confirmed by GC/MS analysis, is considered. 11 components declared by the manufacturer were found to be completely identical, in particular, carvacrol, thymol, and monoterpene hydrocarbons. The other 11 compounds discovered were monoterpenoids and sesquiterpenoids. Research has confirmed the feasibility of using O. vulgare L. essential oil, thymol-carvacrol chemotype, as an antimicrobial component. The dependence of the antimicrobial activity of model samples of liquid plaster on the concentration of Oregano essential oil was established. The essential oil of O. vulgare L. has a variable composition and requires mandatory control of the content of thymol and carvacrol, which inhibit the growth of the studied microorganisms. The antimicrobial effect of a liquid patch containing essential oil of O. vulgare L. at a concentration of 0.15 mg/ml is manifested against test cultures of microorganisms – Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Enterococcus faecalis.

Exploring the Potential of 5 Commercial Essential Oils to Inhibit the Proliferation of A549 Lung Cancer Cells

Globally, lung cancer stands as the primary cause of cancer-related fatalities, securing a spot among the top 10 in newly reported cases. The late detection of lung cancer is often attributed to its indication through commonplace symptoms like coughing. Seeking alternatives, this research investigated the medicinal potential of certain essential oils (EOs) with a rich history in traditional medicine. The study aimed to assess the effectiveness of 5 EOs — Clary Sage, Frankincense, Marjoram, Myrrh, and Thyme as a halal alternative therapy for lung cancer A549 cell line. Notably, based on these investigations’ findings, Myrrh and Thyme emerged as promising candidates, displaying significant capability to inhibit lung cancer cell expansion. Myrrh had the lowest IC50 value, 19 μg/mL, followed by Thyme, 45 μg/mL. In optimisation research, Myrrh resulted in 85% inhibition after 72 hours of exposure to 800 μg/mL concentration. Myrrh demonstrated reduced cell generation and growth rates for cytokinetic study and increased cell death rate. In conclusion, this research was designed to explore the cytotoxic effects of EOs on lung cancer cells using the A549 cell line, leading to the identification of a potential alternative source of halal-compliant pharmaceuticals.

Efficacy and safety of geranium-oregano-thymol formulations to control of dog tick Rhipicephalus sanguineus sensu lato under laboratory and field conditions

The present study evaluated, in laboratory and field, the efficacy and safety of formulations of Pelargonium graveolens (geranium – G), Origanum majorana (oregano - O) commercial essential oils (EO) and thymol (T) to control of Rhipicephalus sanguineus sensu lato. In the laboratory, three formulas (A: 2% tween 80%, B: powder and C: nanoemulsion) by a mixture of these components (GOT) were prepared and evaluated, and the best one was used to assess its safety and field application against R. sanguineus s. l. on naturally infested dogs. Besides the major compounds of the EO used were identified. The results of the lab study showed that formula A (2.5 g of each G + O + T + 2% tween 80 to complete 100 mL) was significantly more effective than the other two formulas tested and exhibited highly effective adulticidal, larvicidal, and ovicidal activity against R. sanguineus s.l. Significant LC50 and LC90 values of GOT were evaluated (13.4 and 21.5 mg/mL, respectively) for the adulticidal activity, (2.81 and 4.46 mg/mL, respectively) for ovicidal activity and (2.44 and 4.45 mg/mL, respectively) for larvicidal activity. The safety of formula A has been proven by the absence of its cytotoxicity on a cell line of human epidermoid carcinoma. Citronella and carvacrol were the major compounds identified in the commercial essential oils of P. graveolens and O. majorana, respectively. Formula A was used in a field control trial for almost 8 months, during the tick infestation season (April to November, 2022). Fourteen naturally infested dogs were divided into two groups, each with seven dogs. One group received formula A spraying five times during an experiment that continued for 8 months, while the other group received treatment with commercially available malathion acaricide. The animals were sprayed on five occasions throughout the experiment (April, June, July, August, and September). The results showed a substantial percentage of effectiveness after the first application of formula A with a 99.3% reduction in tick count at day 28 post-application (PA). In the case of severe infestation 60 days after the first application of formula A (more than 180 ticks per dog), the second application was done, achieving an efficacy of 54.9% at day 3 PA, so an emergency spray was done at day 5 PA to combat the rest of the tick infestation, achieving efficacy of 99% after 3 days. Consequently, a regular spray (third, fourth, and fifth application) was done every 35 days. This regular spray revealed 100% effectiveness at 14 days PA. Biochemical parameters of treated dogs were evaluated to confirm the safety of formula A. Creatinine, ALT, and albumin of the dogs treated with formula A were within the normal range of dogs, while urea and AST were higher than the normal range. In conclusion, formula A can safely treat R. sanguineus s.l. infestations in dogs with regular application every 5 weeks.

Exploring bioactive molecules with fumigation toxicity against the red imported fire ant Solenopsis invicta Buren from commercial essential oils by GC–MS combined with chemometrics

Metabolomics approaches are becoming a powerful analytical technique for exploring bioactive molecules in essential oils. The prevalence of imported red fire ants affected the environment, biodiversity of wildlife, infrastructure, and hypersensitivity reactions of people. Due to public health and environmental issues, essential oils as environmentally friendly alternatives to synthetic chemical insecticides in fire ant management have attracted great attention. However, there is a lack of an objective strategy suitable for identifying bioactive molecules that can guarantee the quality of essential oil biopesticides. Therefore, a metabolomics approach with four main steps, including bioassays, GCMS analysis of chemical constitution, construction of multivariate OPLS and univariate Pearson correlation statistical models, and feature selection, was proposed in this study to verify its potential to find bioactive molecules in essential oils that are effective against red imported fire ants. The fumigation mortalities of 20 commercial essential oils ranged from 0 to 100%. A total of 296 mass features were deconvoluted, and 121 of them were identified. Then, 52 potential bioactive molecules were selected by both VIP > 1.0 and P < 0.05. Finally, 6 of these potential bioactive molecules, (+)− 2-bornanone,.beta.-pinene, eucalyptol, isoborneol, linalool, and L-.alpha.-terpineol, have shown good fumigation toxicity against minor and/or major red imported fire ant workers. This study has, in certain aspects, supported the feasibility of this metabolomics approach. It could be helpful for natural molecules to be alternatives to synthetic chemical insecticides, leading to more environmentally friendly and sustainable management policies for red imported fire ants.

Anti-inflammatory and antioxidant activities of Citrus aurantifolia (Christm.) Swingle essential oil in dystrophic muscle cells: implication of the PGC-1α pathway

The commercial essential oil obtained from the steam distillation of cold-pressed oil from Citrus aurantifolia (Christm.) Swingle fruits (OCA), after chemical characterization by gas chromatography-mass spectrometry (GC-MS), was investigated for antioxidant and anti-inflammatory activities and related signaling pathways in dystrophic muscle cells. The chemical composition of OCA showed 24 compounds with a predominance of monoterpenes, such as limonene (42.6%), cymene (11.8%), α-terpineol (11.8%), terpinolene (5.3%) and γ-terpinene (4.6%). DPHH and ORAC assays showed a significant antioxidant activity of OCA. Because the OCA is rich in limonene, it exhibited marked anti-inflammatory (as indicated by the reduction of TNF- α and NF-κB levels) and antioxidant effects (as indicated by the reduction of 4-HNE-protein adducts, SOD-2, GSR and H2O2 levels) on dystrophic muscle cells. These effects appear to be mediated through the activation of PGC-1α pathway. Therefore, OCA can be considered a promising bioactive for therapeutic applications in dystrophinopathies.

ANTIBACTERIAL PROPERTIES OF COMMERCIAL PEPPERMINT ESSENTIAL OIL AGAINST SOME GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA

The authors of this article conducted research and studied the antibacterial properties of commercial peppermint essential oil (PEO) against several gram-positive and gram-negative bacteria provided by Polish manufacturers of essential oils (Naturalne Aromaty sp. z o.o., Klaj, Poland). Therefore, to conduct research with the aim of to study the antibacterial properties of commercial peppermint essential oil (PEO), an antimicrobial susceptibility test (Kirby-Bauer diffusion test) was used to measure diameters of bacterial growth inhibition zones). In the current study, Gram-negative strains such as Escherichia coli (Migula) Castellani and Chalmers (ATCC® 25922™ ), Escherichia coli (Migula) Castellani and Chalmers (ATCC® 35218™ ), Pseudomonas aeruginosa (Schroeter) Migula (ATCC® 27853™ ) and Gram-positive strains such as Staphylococcus aureus subsp. aureus Rosenbach (ATCC® 29213™ ), methicillin-resistant (MRSA), mecA positive Staphylococcus aureus (NCTC® 12493), Enterococcus faecalis (Andrewes and Horder) Schleifer and Kilpper-Balz (ATCC® 51299™ ) (resistant to vancomycin; sensitive to teicoplanin) and Enterococcus faecalis (Andrewes and Horder) Schleifer and Kilpper-Balz (ATCC® 29212™ ) were used. Results of the current study revealed that resistant to the PEO were Gram-negative bacterial strains, such as E. coli (Migula) Castellani and Chalmers (ATCC® 35218™ ) and P. aeruginosa (Schroeter) Migula (ATCC® 27853™ ) strains. The authors found that the diameters of the inhibition zones after application of PEO were similar to the control samples (96% ethanol). It was also found that after the application of REO, the increase in the diameters of the inhibition zones was 60.3% (p &lt; 0.05) for the Escherichia coli strain (Migula) Castellani and Chalmers (ATCC® 25922™ ) compared to control samples (96% ethanol ). Accordingly, Gram-positive strains such as S. aureus subsp. aureus Rosenbach (ATCC® 29213™ ) and methicillin-resistant S. aureus (NCTC® 12493) were equally resistant to PEO, similarly. On the other hand, Enterococcus faecalis (Andrewes and Horder) Schleifer and Kilpper-Balz (ATCC® 29212™ ) and Enterococcus faecalis (Andrewes and Horder) Schleifer and Kilpper-Balz (ATCC® 51299™ ) were sensitive to PEO. After the application of PEO, the largest diameters of inhibition zones were observed for the E. faecalis strain. The results suggest that commercial peppermint essential oil provided by Polish essential oil manufacturers (Naturalne Aromaty sp. z o.o., Kłaj, Poland) possesses some noteworthy antimicrobial properties. In vivo studies are necessary to calculate the effective dose of EOs and determine their possible side effects and toxicity.