Tea Tree Oil Research Articles

Alternative control of bacterial leaf blight of eucalypt using essential oils

Bacterial leaf blight, attributed to Xanthomonas citri pv. eucalyptorum comb. nov., poses a significant threat to eucalypt nursery and field conditions in Brazil, resulting in substantial annual losses. While various disease management practices are employed, the quest for alternative control methods and environmentally friendly antimicrobial agents remains imperative. Thus, this project was developed to assess the potential efficacy in vitro of essential oils derived from tea tree (Melaleuca alternifolia), copaíba (Copaifera officinalis), and lemongrass (Cymbopogon spp.) against X. citri pv. eucalyptorum. The sensitivity of the bacteria to these oils was examined via antibiogram testing, with each antibiogram subjected to different oil dilutions (6.25 %, 10.00 %, 12.50 %, 25.00 %, 50.00 %, and 100.00 %). Inhibition zones were assessed to determine the inhibitory capacity of each compound on microbial growth, and statistical analysis was conducted using the Mann-Whitney test. Copaíba oil did not exhibit any inhibitory effect on the pathogen growth in vitro. Conversely, both lemongrass and tea tree oils displayed inhibitory effects on the target bacteria, with a minimum inhibitory concentration of 12.50 %. Furthermore, no significant distinctions were observed between the utilization of 12.50 % and 25.00 % concentrations of tea tree, neither between 25.00 % of lemongrass or 50.00 % of tea tree dilutions. These findings may pave the way for new strategies in pathogen management.

High-adhesion antimicrobial composite coating incorporating quaternary chitosan and tea tree oil for enhanced preservation of fruits and vegetables

This study developed high-adhesion quaternary chitosan coatings using amphiphilic HACC-oleic acid conjugates (HACC-OA) to enhance fruit and vegetable preservation. HACC-OA demonstrated improved viscosity and adhesion, providing a stable carrier for tea tree oil (TTO). The resulting TTO@HACC-OA coatings exhibited significantly reduced contact angle (43.7°) and increased retention amount on strawberry surfaces. Furthermore, TTO@HACC-OA demonstrated a lower volatilization rate of TTO (27.8 %) compared to pure TTO (49.5 %) and an enhanced synergistic antimicrobial activity (EC50 = 1.51 mg/mL) against Botrytis cinerea Pers compared to HACC alone (EC50 = 1.58 mg/mL). Preservation experiments revealed that TTO@HACC-OA effectively maintained color and firmness, reduced decay index and weight loss, delayed decline in vitamin C content of strawberries, postponed increase in total phenolic content, and mitigated malondialdehyde accumulation. Therefore, the prepared TTO@HACC-OA composite coating with excellent adhesion ability and preservation effect holds great potential for applications in fruit and vegetable preservation.

An Overview of Commonly Used Natural Alternatives for the Treatment of Androgenetic Alopecia, with Special Emphasis on Rosemary Oil.

Androgenetic alopecia is a chronic dermatological condition in which genetically predisposed individuals undergo progressive hair loss secondary to the effects of circulating androgens. It has been well documented that dihydrotestosterone binds to the androgenic receptors prevalent in the scalp, thus inducing miniaturization of the hair follicle. To date, the only FDA approved medications for the treatment of androgenetic alopecia are finasteride and minoxidil. A plethora of studies have been conducted testing the efficacy of various herbal compounds, but additional research is needed to further establish the concrete efficacy of such natural remedies in treating androgenetic alopecia. Of late, rosemary oil has gained mass popularity as a promising natural alternative. This review article will not only provide a detailed background on this ancient herbal component but will additionally overview all other major herbal alternatives including peppermint oil, tea tree oil, green tea, pumpkin seed oil, saw palmetto, and lavender oil and will summarize the latest clinical studies, which have tested their efficacy for the management of androgenetic alopecia.

Developing Lignin/Pva- Tea Tree Oil Composites for Enhanced Antibacterial and Antifungal Properties

Developing Lignin/Pva- Tea Tree Oil Composites for Enhanced Antibacterial and Antifungal Properties

Anti-gingivitis natural products: Aloe vera gel, tea tree oil mouthwash, turmeric gel, myrrh extract/mouthwash

Gingivitis is an inflammatory gum disease which occurs around the cervical portion of the gum and is classified by its clinical appearance. Gingivitis is very common, and anyone can be affected including but not limited to poor oral care habits. This paper reviews the potential of Aloe Vera, Tea Tree Oil Mouthwash, Turmeric Gel, and Myrrh Extract/Mouthwash. The study also assessed the knowledge and opinions of first-year pharmacy students. The survey part of the study included 5 knowledge-based and 5 opinion-based questions, focusing on the four herbal remedies. The knowledge-based questions showed a 65.7% correct response rate, with the question on turmeric receiving the highest accuracy (94.3%), while the question surveying the participants’ knowledge about the source of information for herbal products received the lowest correct answer rate at 31.4%. Opinion-based questions revealed a positive attitude towards herbal remedies, with about 67.6% to 94.3% strongly agreeing, or agreeing with the potential benefits of the products. The highest agreement rate at 94.3% was obtained for the statement that myrrh can help reduce inflammation in the gums and inhibit the growth of bacteria, thus assisting in the management of gingivitis. Disagreement of opinions was minimal, ranging from 5.7% to 32.3%, indicating a widespread inclination towards positive agreement.

Electricallymodified bacterial cellulose tailored with plant based green materials for infected wound healing applications

Effective treatment of infected wounds remains a challenge due to the rise of antibiotic-resistant microorganisms. The development of advanced materials with strong antimicrobial properties is necessary to address this issue. In this study, a unique composite of electrically modified bacterial cellulose (EBC) with allantoin (ABC) and zein was developed by dipping diffusion method. Morphological structural analysis revealed a uniform distribution of zein and aligned fibers, confirming the synthesis of the ABC-Zein composite. The formation of ABC-Zein was further confirmed by attenuated total reflection-Fourier transform infrared (ATR-FTIR), which displayed additional peaks corresponding to EBC, indicating the incorporation of zein into ABC. X-ray diffraction (XRD) analysis of ABC-Zein demonstrated a similar crystalline structure with EBC. The ABC-Zein showed mechanical integrity (tensile strength: 1.15 ± 0.21 MPa), thermal stability (degradation temperature: 290 °C), porous structure (porosity: 40.23 ± 0.21 %), and hydrophilic (water contact angle: 53.3 ± 5.3°) properties. Furthermore, the antimicrobial agent terpinen-4-ol (T4O), derived from tea tree oil, was incorporated into the ABC-Zein composite. Biological studies confirmed the antimicrobial efficacy (Staphylococcus aureus inhibition: 88.5 ± 7.19 %) and biocompatible (cell viability: 84.95 ± 5.6 %, hemolysis: 4.479 ± 0.39 %) nature of the T4O-ABC-Zein composite. The combined effects of the aligned fiber structure, zein protein, and antimicrobial T4O significantly enhanced infected wound healing by day 7, promoting inflammatory response, granular tissue formation, cell proliferation, and angiogenesis. By day 14, T4O-ABC-Zein facilitated complete wound healing, with reepithelization, collagen I deposition, and downregulation of CD 31, Ki67, and α-SMA. Overall, the innovative T4O-ABC-Zein composite, with an aligned fiber structure, improved biocompatibility, and antimicrobial properties, holds significant potential for the treatment of infected wounds.

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.

New insights from the integration of dapsone, flutamide, tea tree oil, and rose oil as a topical combined microemulsion for the management of Acne Vulgaris: Design, development, and in vitro/in vivo characterization

Acne vulgaris (AV) is a multifactorial sebaceous glands disorder resulting from androgen receptor activation associated with follicular colonization by bacteria. Oral administration of the androgenic antagonist flutamide (FLU) and the antibacterial dapsone (DAP) may cause several side effects. Hence, this study aimed to design a topical microemulsion (ME) combining these drugs to manage AV. Drugs solubility was examined in different oils, surfactants and cosurfactants. Pre-formulation and compatibility studies were performed. The selected MEs were characterized to determine one ME to be investigated regarding stability, and skin irritation as well as antibacterial, anti-inflammatory, and anti-acne activities. Based on the in vitro characterization of the selected MEs, o/w ME (F1) based on 15 % w/w oils (tea tree oil (TTO)/rose oil (RO)) and 40%w/w of tween 20 as surfactant together with transcutol p as co-surfactant was chosen as the optimized ME. The results revealed that F1 showed acceptable pH, viscosity, conductivity, and droplet size (172.6 ± 9.7 nm). The in vitro release and ex vivo permeation of DAP and FLU were efficiently enhanced by their combination in F1. Moreover, F1 exhibited considerable antimicrobial activity against Staphylococcus aureus (S. aureus). Topical application of F1 resulted in low expression levels of interleukin 1β associated with a reduction in the number of androgenic receptors (AR). In conclusion, F1 could be suggested as a combination topical therapy to control AV via its anti-inflammatory, anti-acne, and antimicrobial activities.

Topical Tea Tree Oil versus Systemic Azithromycin in the Treatment of Posterior Marginal Blepharitis

Topical Tea Tree Oil versus Systemic Azithromycin in the Treatment of Posterior Marginal Blepharitis

Exploring the antifungal activity of clove oil (Syzygium aromaticum) against wilt disease caused by Fusarium equiseti in bitter gourd (Momordica charantia L.)

This study investigates the isolation and characterization of Fusarium equiseti, a fungal pathogen causing wilt in bitter gourd. It explores the antifungal activity of essential oils, particularly clove oil, as a natural management approach. The pathogen was isolated from wilt-infected bitter gourd stems and it was confirmed as F. equiseti morphologically by the presence of three-septate falcate macroconidia and globose microconidia and also confirmed molecularly by PCR amplification of the ITS region (PP501044.1). Among the tested essential oils, clove oil demonstrated the highest mycelial growth inhibition (100%) at a concentration of 0.5%, followed by peppermint, wintergreen and tea tree oils. In comparison, neem oil exhibited the least inhibition (15.54%). GC-MS analysis of clove oil revealed 38 compounds, where eugenol is the predominant compound that played a crucial role in antifungal activity. Additionally, metabolic analysis revealed several enriched pathways in F. equiseti during its interaction with clove oil, particularly those involved in lipid metabolism and energy production. Pot culture experiments confirmed the efficacy of clove oil in reducing disease severity and incidence in bitter gourd, achieving a 66.99 % reduction when combined with soil application.Furthermore, clove oil-treated plants showed increased activity of defense-related enzymes, including peroxidase (PO), polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL), suggesting the induction of systemic resistance. This study highlights the potential of clove oil as an eco-friendly alternative to synthetic fungicides for managing F. exquisite-induced wilt in bitter gourd. Future research should focus on optimizing clove oil application methods and understanding its interactions with fungal pathogens at the molecular level to enhance its efficacy in sustainable disease management.

Exploring the antimicrobial efficacy of tea tree essential oil and chitosan against oral pathogens to overcome antimicrobial resistance

BackgroundConsidering that antimicrobial resistance among oral pathogens is a significant concern in dental practice, with broader implications for overall health due to the oral microbiota serving as a reservoir for antibiotic resistance genes (ARGs), research into natural products is crucial for addressing this issue. ObjectiveThis study aimed to evaluate tea tree oil (TTO) and chitosan (CH) performance against oral pathogens, including mixed-species biofilm, and its effects on bacteria growth, in addition to chemical characterization and cytotoxicity of TTO. MethodsTea Tree Oil and low molecular weight chitosan were used in this study. The chemical composition of TTO was analyzed using gas chromatography coupled with mass spectrometry (GC-MS). To evaluate TTO's antimicrobial properties, time-kill and cell viability assays were conducted. Additionally, minimum inhibitory concentration (MIC), minimum microbiocidal concentration (MMC), checkerboard, and biofilm assays were performed using TTO and CH alone and in combination. ResultsTTO chromatography peaks found consistent with the standard ISO4730:2017 and literature. TTO and CH exhibited inhibitory activity against all tested microorganisms. The predominantly microbiostatic activity of TTO is probably related to terpinen-4-ol associated with terpinene. The oil at MIC value was able to delay the log phase of Aggregatibacter actinomycetemcomitans growth. Fibroblasts (L929) viability remained above 70 % during 24 h for TTO concentrations ranging from 0.5 to 0.0625 mg/ml. TTO-CH combination showed a synergistic activity (FIC = 0.5) against A. actinomycetemcomitans and Streptococcus sanguinis, at a concentration of 0,25MIC for both species. The compounds at MIC concentration inhibited both monospecies and mixed-species biofilms studied bacteria to the same extent as the azithromycin control. ConclusionTTO and CH demonstrated efficacy in combating oral pathogens and TTO-CH combination offers a promising approach to confront microbial resistance in the oral environment.

Effects of tea tree oil and cefepime treatments on morphological, genetic, histopathological, immunohistochemistry, and biochemical assessments in liver and kidney of Escherichia coli infected rats

The current study evaluated the influence of the treatment with tea tree oil and cefepime on morpho- genetic, histo-immunohistochemical, and biochemical assessments in rats experimentally challenged with Escherichia coli ATCC 4157™. Thirty adult male rats were divided into control, E. coli infected positive group (1×108CFU/I/P/once), E. coli with cefepime-supplemented group (45 mg/kg bw/I/M/day), E. coli with tea tree oil treated group (1.5 ml/per os/day), and the E. coli-challenged group that received a combination of tea tree oil and cefepime. E. coli infection induced morphological changes in color and texture of both liver and kidney. The transcription levels of the PHLPP2 and Nrf2 genes were noticeably lowered in all treated groups related to the E. coli group. Regarding the TLR4 expression, it was clearly up-regulated in the E. coli group in comparison to other groups, while CD14 gene decreased clearly in all treated groups compared to the positive group. The findings revealed that RBC, HGB, and PCV were clearly higher in the positive group compared to all treated groups. AST, ALT, and ALP, total bilirubin and its fractions, urea, and creatinine maximized in the positive group and decreased by the treatment, especially in the E+CF+oil treated group. Regarding the redox balance, MDA levels of MDA were notably reduced in the E+CF+oil treated group compared to the positive and the other treated groups. GSH, SOD, and GPX were significantly induced in the E. coil-treated group and decreased significantly with treatment. Overall, cefepime is highly safe especially when dually supplied with tea tree oil for mitigating E. coli adverse impact.

Development, Optimization, and Evaluation of New Gel Formulations with Cyclodextrin Complexes and Volatile Oils with Antimicrobial Activity.

This study aimed to develop and evaluate hydrogels containing a cyclodextrin complex with clove essential oil and other free volatile oils with antimicrobial properties (tea tree and rosemary essential oils), focusing on their pharmaco-technical and rheological characteristics. The formulations varied in the Carbopol 940 (a hydrophilic polymer) and volatile oils' concentrations. Rheological analysis indicated that the gels displayed pseudoplastic behavior, with the flow index (n) values below 1, ensuring appropriate consistency and handling. The results showed that increasing the Carbopol concentration significantly enhanced the yield stress, consistency index, and viscosity, with gel B, containing 1% Carbopol, 1.5% tea tree essential oil, and 1.5% rosemary essential oil, demonstrating optimal stability and rheological properties. At the same time, the concentration of volatile oils was found to modulate the gels' flow parameters, but their effect was less pronounced than that of the gel-forming polymer. Antimicrobial testing revealed that both gel B and gel E (containing 1% Carbopol, 2% tea tree essential oil, and 2% rosemary essential oil) exhibited antimicrobial activity against Gram-positive, Gram-negative bacteria, and Candida spp., with gel E showing superior efficacy against Candida tropicalis. The antimicrobial effects were likely influenced by the higher concentrations of tea tree and rosemary essential oils in gel E. Overall, the study demonstrates that the concentration of Carbopol 940 primarily determines the gel's rheological behavior, while volatile oil concentration modulates antimicrobial effectiveness.

Microbiological studies on Escherichia coli and Klebsiella pneumoniae causing vaginal and urinary tract inflammation; prevalence, antibiotics-resistance and natural products susceptibility

Great efforts have been made for controlling multidrug-resistant bacteria (MDR). The antibacterial activity of natural products is an effective strategy due to its beneficial effects on human health. This study focused on the isolation, identification, studying the prevalence and the susceptibility of Escherichia coli and Klebsiella spp. to some natural products. After isolation, the isolates primarily identified using biochemical and API tests. Then, the antibiotic susceptibility test was done to reveal the most antibiotics resistant isolates before further identification of Escherichia coli and Klebsiella pneumoniae using phoA and gyrA genes, respectively. Furthermore, the sensitivity of the most antibiotics resistant isolates to apple cider vinegar (ACV), garlic oil (GO), coconut oil (CNO), tea tree oil (TTO), and lavender oil (LO) was estimated. All tested extracts especially ACV and TTO showed good antibacterial activity against MRD selected isolates. Statistical analysis indicated that there was significant difference in ACV and TTO antibacterial response between Escherichia coli and Klebsiella pneumoniae whereas there was no significant difference between natural products activity when tested against Escherichia coli and Klebsiella pneumoniae seperatly. GC-MS spectroscopy analysis revealed the most prominent active constituents present in tested ACV and TTO. Analyzing the 16S rRNA sequence confirmed the two most MRD pathogenic isolates that showed sensitivity to ACV and TTO were Escherichia coli MS1 and Klebsiella pneumoniae MS47, respectively. Essential oils tea tree and apple cider vinegar showed good antibacterial activities against antibiotics-resistant Escherichia coli and Klebsiella pneumoniae causing vaginal and urinary tract inflammation.

A chitosan-modified tea tree oil self-nanoemulsion improves antibacterial effects in vivo and in vitro and promotes wound healing by influencing metabolic processes against multidrug-resistant bacterial infections

Infectious diseases, especially multidrug-resistant bacterial infections, have caused crises and majorly disrupted public health and economic stability worldwide. Many natural essential oils, especially tea tree oil, have potential to treat multidrug-resistant bacteria, such as H. pylori and P. aeruginosa. However, there are some problems need to be solved, such as poor stability upon light or oxygen exposure. Therefore, it is urgent to develop the ideal formation to tackle these difficulties. Herein, we reported the novel chitosan-modified self-nanoemulsion (TNE) encapsulating natural essential tea tree oil with strong antibacterial and stability characterize. In this study, we found that this self-nanoemulsion (size: 212 nm, PDI: 0.124, zeta potential: −20.5 mV, 6 % tea tree oil) not only had physical properties, good stability and tissue safety, but also had better antibacterial synergism (2–8 times) than that of water suspension against various multidrug-resistant bacterial (such as H. pylori, MRSA and P. aeruginosa). Additionally, TNE showed high antibacterial effectiveness in vivo, reduced inflammation, promoted ulcer healing after H. pylori infection and accelerated wound healing after P. aeruginosa infection. Importantly, this novel self-nanoemulsion can induce 274 protein down-regulated and 251 protein up-regulated, and disrupt H. pylori metabolic processes (glyoxylate, dicarboxylic acid, glutamate and tryptophan metabolism) and reduced its viability, leading to significant synergistic antibacterial effects. TNE is a potential treatment for skin wounds or ulcers caused by multidrug-resistant bacterial infections.

Formulation and characterization of tea tree and jojoba oils nano-emulgel for in-vivo wound healing assessment

Cutaneous wounds are the most common surgical affections among living organisms worldwide, and their healing may be interrupted by several factors. This study aimed to formulate and evaluate the antioxidant, anti-inflammatory, and antimicrobial activity of tea tree and jojoba oils nano-emulsions, additionally, investigating the cytotoxicity of the optimized formula was investigated on normal human lung fibroblast cells (WI-38) by MTT colorimetric assay, additionally its in-vivo wound healing. Nano-emulsions (NEs) were prepared using a high-energy method and characterized by Transmission electron microscopy (TEM), Zeta potential, droplet size, and poly dispersive index (PDI). Nano-emulgel (NEG) was formulated by mixing the standard NE with carbopol® 940. For in-vivo wound healing, thirty adult female albino rats were assigned into control, moist exposed burn ointment (Mebo), and NEG-treated groups. The healing was assessed by analysis of superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and histopathology in healed wound tissues. All formulations demonstrated antioxidant, anti-inflammatory, and antimicrobial activity against Bacillus Subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Enterococcus faecalis, and Candida albicans. The CC50 of the optimized formula was 453.82± 3.87 µg/mL, with a mean droplet size of 105.4 nm and a zeta potential of −39.2 ± 2.1 mV. NEG enhanced wound closure compared to Mebo-treated and control groups. Also, MDA significantly decreased and SOD significantly increased in NEG and Mebo-treated groups compared to the control (p ˂ 0.05). TNF-α, and IL-1β significantly decreased in NEG and Mebo-treated compared to the control (p < 0.05). Histopathology revealed reduced inflammatory cell infiltration, rapid epithelization, and increased collagen deposition in NEG-treated wound tissues compared to the control and Mebo-treated wounds. In conclusion, the NEG containing tea tree and jojoba oils demonstrated significant antioxidant, anti-inflammatory, antimicrobial, and wound healing activities.

Tea Tree Oil Effect on Dimensional Change and Detail Reproduction of Addition Silicon Impression Material

Objective: Impression materials are thought to be the one of the primary sources of cross infection between patients and dentists. However, it was discovered that disinfection of the impression is not conducted routinely in ordinary dental treatment. Disinfection of addition silicon impression, whether by immersion or spray should not produce dimensional or detail errors. The purpose of this study was to examine the immersion of addition silicon impression material in tea tree oil and its influence on dimensional stability and detail reproduction of the addition silicon imprint material. Materials and Methods: This study employed a total of 120 heavy- and light-body addition silicon impression material specimens. The specimens were randomly sorted and immersed into six groups. These test groups where four concentrations of TTO (0.25%, 0.5%, 0.75%, and 1%), and the other two groups were distilled water (negative control) and 2% glutaraldehyde (positive control). All specimens were immersed for 10 minutes in the testing solutions. Each of the six groups had 20 specimens separated into two subgroups. Results: There were no statistically significant differences in linear dimensional changes and detail reproduction among all test groups. Conclusion: The addition silicon impression material may be safely submerged in TTO for 10 minutes to disinfect it without impairing its dimensional correctness or detail replication of the impression.

In vitro culture and morphological observation of human eye demodex mites

The prevalence of human Demodex mites has surged in recent years, prompting significant concern among both patients and the medical community. This study aimed to investigate the survival duration and morphological alterations of Demodex folliculorum under diverse temperature conditions and in various culture media. We employed the eyelash sampling technique to procure the mites. The collected specimens were then subjected to culture at two distinct temperature ranges (16–22 °C and 4 °C) across a spectrum of media, including 30% tea tree oil (TTO), phosphate-buffered saline (PBS), pure water, 0.9% physiological saline, 5 µg/ml propidium iodide (PI), liquid paraffin, glycerol, and a blank culture medium. Post-administration, the mites’ activity and morphological changes were meticulously documented. Our findings indicate that the survival span of Demodex mites within the same medium was notably extended at 4 °C compared to room temperature. Specifically, under 4 °C, the use of liquid paraffin as a culture medium yielded the longest survival time of 12 days, surpassing all other conditions. Remarkably, the morphological integrity of the mites in this group remained largely unaltered. These results suggest that 4 °C is the optimal temperature for the in vitro cultivation of Demodex mites, offering insights into the environmental preferences of these organisms and potentially informing future therapeutic strategies.

Development of synergistic antifungal in situ gel of miconazole nitrate loaded microemulsion as a novel approach to treat vaginal candidiasis

Limited solubility is the main cause of the low local availability of anti-candidiasis drug, miconazole nitrate (MN). The study’s objective was to develop and characterize microemulsion (ME) based temperature-triggered in situ gel of MN for intravaginal administration to enhance local availability and antifungal activity. The solubility of MN was initially studied in different oils, surfactants, and co-surfactants. Then, pseudo-ternary phase diagrams were constructed to select the best ratio of various components. The ME formulations were characterized by thermodynamic study, droplet size, polydispersity index (PDI), viscosity, and in-vitro antifungal mean inhibition zone (MIZ). Selected MEs were incorporated into different in situ gel bases using a combination of two thermosensitive polymers (poloxamer (PLX) 407 and 188), with 0.6% of hydroxypropyl methylcellulose (HPMC K4M) and gellan gum (GG) as mucoadhesive polymer. ME-based gels (MG) were investigated for gelation temperature, gelation time, viscosity, spreadability, mucoadhesive strength, in vitro release profile, and MIZ test. Furthermore, the optimum MG was assessed for in vivo animal irritation test and FESEM investigation. Tea tree oil, lavender oil, tween 80, and propylene glycol (PG) were chosen for ME preparation for the optimal formulation; formulation ME7 and ME10 were chosen. After incorporation of the selected formulation into a mixture of P407 and P188 (18:2% w/w) with 0.6% mucoadhesive polymer, the resultant MG formulation (MG1) revealed optimum gelation temperature (33 ± 0.01℃) and appropriate viscosity with enhanced sustained release (98%) and retention through sheep vaginal mucosa, MG1 exhibited a better MIZ compared to the 2% MN gel formulation and the marketed MN product, and no rabbit vagina irritation. In conclusion, the miconazole nitrate-loaded MG-based formula sustained the duration of action and better antifungal activity than the marketed miconazole nitrate formulation.

Safety and efficacy of a feed additive consisting of an essential oil derived from leaves and terminal branchlets of Melaleuca alternifolia (Maiden & Betche) Cheel (tea tree oil) for use in all animal species (FEFANA asbl).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of tea tree oil obtained from leaves and terminal branchlets of Melaleuca alternifolia (Maiden & Betche) Cheel when used as a sensory additive for all animal species. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that tea tree oil was very unlikely to be of safety concern for long-living and reproductive animals and is of no concern for target species for fattening at the following concentrations in complete feed: 1.1 mg/kg for chickens for fattening, 1.5 mg/kg for turkeys for fattening, 1.7 mg/kg for laying hens, 2.0 mg/kg for piglets, 2.4 mg/kg for pigs for fattening, 3.1 mg/kg for sows, 5.0 mg/kg for veal calves (milk replacer) and salmonids, 4.4 mg/kg for cattle for fattening, sheep/goats and horses, 2.9 mg/kg for dairy cows, 1.8 mg/kg for rabbits, 0.9 mg/kg for cats, 5.3 mg/kg for dogs, 6.6 for crustaceans and 15 mg/kg for ornamental fish. These conclusions were extrapolated to other physiologically related species. For any other species, the additive is very unlikely to be of safety concern at 1.1 mg/kg complete feed. No concerns for consumers and the environment were identified following the use of the additive up to the highest safe use level in feed. Regarding user safety, tea tree oil should be considered as an irritant to skin and eyes and as a dermal and respiratory sensitiser. It is classified as a reprotoxic substance (category 1B) following CLP criteria and should be handled accordingly. Since M. alternifolia and its preparations were recognised to flavour food and its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary.